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Sample records for switchgrass panicum virgatum

  1. Breaking seed dormancy of switchgrass (Panicum virgatum L.): A review

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) is a perennial warm-season grass identified as a model species for bioenergy feedstock. Established switchgrass stand are very resilient to environmental fluctuations, however, seed dormancy and weak seedling vigor make establishment difficult. Seeds with high leve...

  2. Genome-size variation in switchgrass (Panicum virgatum): flow cytometry and cytology reveal rampant aneuploidy

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    Switchgrass (Panicum virgatum L.), a native perennial dominant of the prairies of North America, has been targeted as a model herbaceous species for biofeedstock development. A flow-cytometric survey of a core set of 11 primarily upland polyploid switchgrass accessions indicated that there was con...

  3. Five nuclear loci resolve the polyploid history of switchgrass (Panicum virgatum L.) and relatives.

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    Triplett, Jimmy K; Wang, Yunjing; Zhong, Jinshun; Kellogg, Elizabeth A

    2012-01-01

    Polyploidy poses challenges for phylogenetic reconstruction because of the need to identify and distinguish between homoeologous loci. This can be addressed by use of low copy nuclear markers. Panicum s.s. is a genus of about 100 species in the grass tribe Paniceae, subfamily Panicoideae, and is divided into five sections. Many of the species are known to be polyploids. The most well-known of the Panicum polyploids are switchgrass (Panicum virgatum) and common or Proso millet (P. miliaceum). Switchgrass is in section Virgata, along with P. tricholaenoides, P. amarum, and P. amarulum, whereas P. miliaceum is in sect. Panicum. We have generated sequence data from five low copy nuclear loci and two chloroplast loci and have clarified the origin of P. virgatum. We find that all members of sects. Virgata and Urvilleana are the result of diversification after a single allopolyploidy event. The closest diploid relatives of switchgrass are in sect. Rudgeana, native to Central and South America. Within sections Virgata and Urvilleana, P. tricholaenoides is sister to the remaining species. Panicum racemosum and P. urvilleanum form a clade, which may be sister to P. chloroleucum. Panicum amarum, P. amarulum, and the lowland and upland ecotypes of P. virgatum together form a clade, within which relationships are complex. Hexaploid and octoploid plants are likely allopolyploids, with P. amarum and P. amarulum sharing genomes with P. virgatum. Octoploid P. virgatum plants are formed via hybridization between disparate tetraploids. We show that polyploidy precedes diversification in a complex set of polyploids; our data thus suggest that polyploidy could provide the raw material for diversification. In addition, we show two rounds of allopolyploidization in the ancestry of switchgrass, and identify additional species that may be part of its broader gene pool. This may be relevant for development of the crop for biofuels.

  4. Five nuclear loci resolve the polyploid history of switchgrass (Panicum virgatum L. and relatives.

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    Jimmy K Triplett

    Full Text Available Polyploidy poses challenges for phylogenetic reconstruction because of the need to identify and distinguish between homoeologous loci. This can be addressed by use of low copy nuclear markers. Panicum s.s. is a genus of about 100 species in the grass tribe Paniceae, subfamily Panicoideae, and is divided into five sections. Many of the species are known to be polyploids. The most well-known of the Panicum polyploids are switchgrass (Panicum virgatum and common or Proso millet (P. miliaceum. Switchgrass is in section Virgata, along with P. tricholaenoides, P. amarum, and P. amarulum, whereas P. miliaceum is in sect. Panicum. We have generated sequence data from five low copy nuclear loci and two chloroplast loci and have clarified the origin of P. virgatum. We find that all members of sects. Virgata and Urvilleana are the result of diversification after a single allopolyploidy event. The closest diploid relatives of switchgrass are in sect. Rudgeana, native to Central and South America. Within sections Virgata and Urvilleana, P. tricholaenoides is sister to the remaining species. Panicum racemosum and P. urvilleanum form a clade, which may be sister to P. chloroleucum. Panicum amarum, P. amarulum, and the lowland and upland ecotypes of P. virgatum together form a clade, within which relationships are complex. Hexaploid and octoploid plants are likely allopolyploids, with P. amarum and P. amarulum sharing genomes with P. virgatum. Octoploid P. virgatum plants are formed via hybridization between disparate tetraploids. We show that polyploidy precedes diversification in a complex set of polyploids; our data thus suggest that polyploidy could provide the raw material for diversification. In addition, we show two rounds of allopolyploidization in the ancestry of switchgrass, and identify additional species that may be part of its broader gene pool. This may be relevant for development of the crop for biofuels.

  5. Selecting, Establishing, and Managing Switchgrass (Panicum virgatum) for Biofuels

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    Parrish, David J.; Fike, John H.

    Switchgrass is being widely considered as a feedstock for biofuel production. Much remains to be learned about ideal feedstock characteristics, but switchgrass offers many advantages already and can perhaps be manipulated to offer more. When planning to grow switchgrass, select a cultivar that is well adapted to the location - generally a lowland cultivar for the southern United States and an upland cultivar at higher latitudes. Plant non-dormant seed after soils are well warmed, preferably with no-till methods and always with good weed control. Except for weeds, few pests appear to be widespread; but disease and insect pests could become more important as acreages increase. Fertilization requirements are relatively low, with 50 kg N/ha/year being a good “generic” recommendation where a single harvest is taken after plants have senesced; more will be needed if biomass is harvested while still green. Switchgrass should be harvested no more than twice per year and may generally be expected to produce 12 to ≥20 mg/ha/year across its usual range of distribution. A single harvest may provide for maximum sustainable yields - especially if the harvest is taken after tops die back at the end of the season. Several harvesting technologies are available, but the preferred technology may depend on logistics and economics associated with the local processing point, or biorefinery.

  6. Evaluation of parameters affecting switchgrass tissue culture: toward a consolidated procedure forAgrobacterium-mediated transformation of switchgrass (Panicum virgatum).

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    Lin, Chien-Yuan; Donohoe, Bryon S; Ahuja, Neha; Garrity, Deborah M; Qu, Rongda; Tucker, Melvin P; Himmel, Michael E; Wei, Hui

    2017-01-01

    Switchgrass ( Panicum virgatum ), a robust perennial C4-type grass, has been evaluated and designated as a model bioenergy crop by the U.S. DOE and USDA. Conventional breeding of switchgrass biomass is difficult because it displays self-incompatible hindrance. Therefore, direct genetic modifications of switchgrass have been considered the more effective approach to tailor switchgrass with traits of interest. Successful transformations have demonstrated increased biomass yields, reduction in the recalcitrance of cell walls and enhanced saccharification efficiency. Several tissue culture protocols have been previously described to produce transgenic switchgrass lines using different nutrient-based media, co-cultivation approaches, and antibiotic strengths for selection. After evaluating the published protocols, we consolidated these approaches and optimized the process to develop a more efficient protocol for producing transgenic switchgrass. First, seed sterilization was optimized, which led to a 20% increase in yield of induced calluses. Second, we have selected a N 6 macronutrient/B 5 micronutrient (NB)-based medium for callus induction from mature seeds of the Alamo cultivar, and chose a Murashige and Skoog-based medium to regenerate both Type I and Type II calluses. Third, Agrobacterium -mediated transformation was adopted that resulted in 50-100% positive regenerated transformants after three rounds (2 weeks/round) of selection with antibiotic. Genomic DNA PCR, RT-PCR, Southern blot, visualization of the red fluorescent protein and histochemical β-glucuronidase (GUS) staining were conducted to confirm the positive switchgrass transformants. The optimized methods developed here provide an improved strategy to promote the production and selection of callus and generation of transgenic switchgrass lines. The process for switchgrass transformation has been evaluated and consolidated to devise an improved approach for transgenic switchgrass production. With the

  7. Early lignin pathway enzymes and routes to chlorogenic acid in switchgrass (Panicum virgatum L.).

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    Escamilla-Treviño, Luis L; Shen, Hui; Hernandez, Timothy; Yin, Yanbin; Xu, Ying; Dixon, Richard A

    2014-03-01

    Studying lignin biosynthesis in Panicum virgatum (switchgrass) has provided a basis for generating plants with reduced lignin content and increased saccharification efficiency. Chlorogenic acid (CGA, caffeoyl quinate) is the major soluble phenolic compound in switchgrass, and the lignin and CGA biosynthetic pathways potentially share intermediates and enzymes. The enzyme hydroxycinnamoyl-CoA: quinate hydroxycinnamoyltransferase (HQT) is responsible for CGA biosynthesis in tobacco, tomato and globe artichoke, but there are no close orthologs of HQT in switchgrass or in other monocotyledonous plants with complete genome sequences. We examined available transcriptomic databases for genes encoding enzymes potentially involved in CGA biosynthesis in switchgrass. The protein products of two hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyltransferase (HCT) genes (PvHCT1a and PvHCT2a), closely related to lignin pathway HCTs from other species, were characterized biochemically and exhibited the expected HCT activity, preferring shikimic acid as acyl acceptor. We also characterized two switchgrass coumaroyl shikimate 3'-hydroxylase (C3'H) enzymes (PvC3'H1 and PvC3'H2); both of these cytochrome P450s had the capacity to hydroxylate 4-coumaroyl shikimate or 4-coumaroyl quinate to generate caffeoyl shikimate or CGA. Another switchgrass hydroxycinnamoyl transferase, PvHCT-Like1, is phylogenetically distant from HCTs or HQTs, but exhibits HQT activity, preferring quinic acid as acyl acceptor, and could therefore function in CGA biosynthesis. The biochemical features of the recombinant enzymes, the presence of the corresponding activities in plant protein extracts, and the expression patterns of the corresponding genes, suggest preferred routes to CGA in switchgrass.

  8. Global changes in mineral transporters in tetraploid switchgrasses (Panicum virgatum L.

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    Nathan A. Palmer

    2014-01-01

    Full Text Available Switchgrass (Panicum virgatum L is perennial, C4 grass with great potential as a biofuel crop. An in-depth understanding of the mechanisms that control mineral uptake, distribution and remobilization will benefit sustainable production. Nutrients are mobilized from aerial portions to below-ground crowns and rhizomes as a natural accompaniment to above-ground senescence post seed-set. Mineral uptake and remobilization is dependent on transporters, however, little if any information is available about the specific transporters that are needed and how their relative expression changes over a growing season. Using well-defined classes of mineral transporters, we identified 520 genes belonging to 40 different transporter classes in the tetraploid switchgrass genome. Expression patterns were determined for many of these genes using publically available transcriptomic datasets obtained from both greenhouse and field grown plants. Certain transporters showed strong temporal patterns of expression in distinct developmental stages of the plant. Gene-expression was verified for selected transporters using qRT-PCR. By and large these analyses confirmed the developmental stage-specific expression of these genes. Mineral analyses indicated that K, Fe, Mg, Co and As had a similar pattern of accumulation with apparent limited remobilization at the end of the growing season. These initial analyses will serve as a foundation for more detailed examination of the nutrient biology of switchgrass.

  9. Switchgrass (Panicum virgatum) Intercropping within Managed Loblolly Pine (Pinus taeda) Does Not Affect Wild Bee Communities.

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    Campbell, Joshua W; Miller, Darren A; Martin, James A

    2016-11-04

    Intensively-managed pine ( Pinus spp.) have been shown to support diverse vertebrate communities, but their ability to support invertebrate communities, such as wild bees, has not been well-studied. Recently, researchers have examined intercropping switchgrass ( Panicum virgatum ), a native perennial, within intensively managed loblolly pine ( P. taeda ) plantations as a potential source for cellulosic biofuels. To better understand potential effects of intercropping on bee communities, we investigated visitation of bees within three replicates of four treatments of loblolly pine in Mississippi, U.S.A.: 3-4 year old pine plantations and 9-10 year old pine plantations with and without intercropped switchgrass. We used colored pan traps to capture bees during the growing seasons of 2013 and 2014. We captured 2507 bees comprised of 18 different genera during the two-year study, with Lasioglossum and Ceratina being the most common genera captured. Overall, bee abundances were dependent on plantation age and not presence of intercropping. Our data suggests that switchgrass does not negatively impact or promote bee communities within intensively-managed loblolly pine plantations.

  10. Accelerating the Switchgrass (Panicum virgatum L.) Breeding Cycle Using Genomic Selection Approaches

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    Lipka, Alexander E.; Lu, Fei; Cherney, Jerome H.; Buckler, Edward S.; Casler, Michael D.; Costich, Denise E.

    2014-01-01

    Switchgrass (Panicum virgatum L.) is a perennial grass undergoing development as a biofuel feedstock. One of the most important factors hindering breeding efforts in this species is the need for accurate measurement of biomass yield on a per-hectare basis. Genomic selection on simple-to-measure traits that approximate biomass yield has the potential to significantly speed up the breeding cycle. Recent advances in switchgrass genomic and phenotypic resources are now making it possible to evaluate the potential of genomic selection of such traits. We leveraged these resources to study the ability of three widely-used genomic selection models to predict phenotypic values of morphological and biomass quality traits in an association panel consisting of predominantly northern adapted upland germplasm. High prediction accuracies were obtained for most of the traits, with standability having the highest ten-fold cross validation prediction accuracy (0.52). Moreover, the morphological traits generally had higher prediction accuracies than the biomass quality traits. Nevertheless, our results suggest that the quality of current genomic and phenotypic resources available for switchgrass is sufficiently high for genomic selection to significantly impact breeding efforts for biomass yield. PMID:25390940

  11. Exogenous GR24 Alleviates Cadmium Toxicity by Reducing Cadmium Uptake in Switchgrass (Panicum virgatum) Seedlings.

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    Tai, Zhenglan; Yin, Xinqiang; Fang, Zhigang; Shi, Gaoling; Lou, Laiqing; Cai, Qingsheng

    2017-07-29

    Strigolactones (SLs) are classified into plant hormones, playing a key role as a mediator of plant growth in response to several abiotic stresses, including drought and salinity. However, the role of SLs in cadmium (Cd)-induced stress to plants is still unknown. The physiological responses of switchgrass ( Panicum virgatum ) stressed in 10 μmol L -1 Cd to exogenous synthetic SLs analog, GR24 were studied in hydroponics. The Cd stress significantly caused the adverse effects on plant growth and root morphology, inhibited photosynthesis, but boosted lipid peroxidation of Switchgrass seedlings. After treatment of 1 μmol L -1 GR24, the above adverse effects caused by Cd stress were significantly alleviated, mainly reflects in improvement of shoot biomass, relative water content, root development, chlorophyll contents, activities of typical antioxidant enzymes, nutrient uptake. The reason for exogenous GR24 alleviating cadmium toxicity might be owing to that exogenous GR24 promoted the content of endogenous SLs, increased some essential element Fe (iron), Zn (zinc), Mn (manganese) and Cu (copper) uptake and reduced cadmium uptake, accumulation and partition in shoot of switchgrass seedlings.

  12. Physiological Evaluation of Alkali-Salt Tolerance of Thirty Switchgrass (Panicum virgatum Lines.

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    Guofu Hu

    Full Text Available Soil salt-alkalization is a major limiting factor for crop production in many regions. Switchgrass (Panicum virgatum L. is a warm-season C4 perennial rhizomatous bunchgrass and a target lignocellulosic biofuel species. The objective of this study was to evaluate relative alkali-salt tolerance among 30 switchgrass lines. Tillers of each switchgrass line were transplanted into pots filled with fine sand. Two months after transplanting, plants at E5 developmental stage were grown in either half strength Hoagland's nutrient solution with 0 mM Na+ (control or half strength Hoagland's nutrient solution with 150 mM Na+ and pH of 9.5 (alkali-salt stress treatment for 20 d. Alkali-salt stress damaged cell membranes [higher electrolyte leakage (EL], reduced leaf relative water content (RWC, net photosynthetic rate (Pn, stomatal conductance (gs, and transpiration rate (Tr. An alkali-salt stress tolerance trait index (ASTTI for each parameter was calculated based on the ratio of the value under alkali-salt stress and the value under non-stress conditions for each parameter of each line. Relative alkali-salt tolerance was determined based on principal components analysis and cluster analysis of the physiological parameters and their ASTTI values. Significant differences in alkali-salt stress tolerance were found among the 30 lines. Lowland lines TEM-SEC, Alamo, TEM-SLC and Kanlow were classified as alkali-salt tolerant. In contrast, three lowland lines (AM-314/MS-155, BN-13645-64 and two upland lines (Caddo and Blackwell-1 were classified as alkali-salt sensitive. The results suggest wide variations exist in alkali-salt stress tolerance among the 30 switchgrass lines. The approach of using a combination of principal components and cluster analysis of the physiological parameters and related ASTTI is feasible for evaluating alkali-salt tolerance in switchgrass.

  13. Physiological Evaluation of Alkali-Salt Tolerance of Thirty Switchgrass (Panicum virgatum) Lines.

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    Hu, Guofu; Liu, Yiming; Zhang, Xunzhong; Yao, Fengjiao; Huang, Yan; Ervin, Erik H; Zhao, Bingyu

    2015-01-01

    Soil salt-alkalization is a major limiting factor for crop production in many regions. Switchgrass (Panicum virgatum L.) is a warm-season C4 perennial rhizomatous bunchgrass and a target lignocellulosic biofuel species. The objective of this study was to evaluate relative alkali-salt tolerance among 30 switchgrass lines. Tillers of each switchgrass line were transplanted into pots filled with fine sand. Two months after transplanting, plants at E5 developmental stage were grown in either half strength Hoagland's nutrient solution with 0 mM Na+ (control) or half strength Hoagland's nutrient solution with 150 mM Na+ and pH of 9.5 (alkali-salt stress treatment) for 20 d. Alkali-salt stress damaged cell membranes [higher electrolyte leakage (EL)], reduced leaf relative water content (RWC), net photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (Tr). An alkali-salt stress tolerance trait index (ASTTI) for each parameter was calculated based on the ratio of the value under alkali-salt stress and the value under non-stress conditions for each parameter of each line. Relative alkali-salt tolerance was determined based on principal components analysis and cluster analysis of the physiological parameters and their ASTTI values. Significant differences in alkali-salt stress tolerance were found among the 30 lines. Lowland lines TEM-SEC, Alamo, TEM-SLC and Kanlow were classified as alkali-salt tolerant. In contrast, three lowland lines (AM-314/MS-155, BN-13645-64) and two upland lines (Caddo and Blackwell-1) were classified as alkali-salt sensitive. The results suggest wide variations exist in alkali-salt stress tolerance among the 30 switchgrass lines. The approach of using a combination of principal components and cluster analysis of the physiological parameters and related ASTTI is feasible for evaluating alkali-salt tolerance in switchgrass.

  14. The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum

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    Elizabeth R. Milano

    2016-11-01

    Full Text Available The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures, and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mapping population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq, and mapped quantitative trait loci (QTL for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTL for multiple traits, we did not find any large-effect QTL that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis, and that similar loci may underlie divergence across the geographic range of the ecotypes.

  15. The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum)

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    Milano, Elizabeth R.; Lowry, David B.; Juenger, Thomas E.

    2016-01-01

    The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures, and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum) ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mapping population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq, and mapped quantitative trait loci (QTL) for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTL for multiple traits, we did not find any large-effect QTL that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis, and that similar loci may underlie divergence across the geographic range of the ecotypes. PMID:27613751

  16. Targeted mutagenesis in tetraploid switchgrass (Panicum virgatum L.) using CRISPR/Cas9.

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    Liu, Yang; Merrick, Paul; Zhang, Zhengzhi; Ji, Chonghui; Yang, Bing; Fei, Shui-Zhang

    2018-02-01

    The CRISPR/Cas9 system has become a powerful tool for targeted mutagenesis. Switchgrass (Panicum virgatum L.) is a high yielding perennial grass species that has been designated as a model biomass crop by the U.S. Department of Energy. The self-infertility and high ploidy level make it difficult to study gene function or improve germplasm. To overcome these constraints, we explored the feasibility of using CRISPR/Cas9 for targeted mutagenesis in a tetraploid cultivar 'Alamo' switchgrass. We first developed a transient assay by which a non-functional green-fluorescent protein gene containing a 1-bp frameshift insertion in its 5' coding region was successfully mutated by a Cas9/sgRNA complex resulting in its restored function. Agrobacterium-mediated stable transformation of embryogenic calli derived from mature caryopses averaged a 3.0% transformation efficiency targeting the genes of teosinte branched 1(tb1)a and b and phosphoglycerate mutase (PGM). With a single construct containing two sgRNAs targeting different regions of tb1a and tb1b genes, primary transformants (T0) containing CRISPR/Cas9-induced mutations were obtained at frequencies of 95.5% (tb1a) and 11% (tb1b), respectively, with T0 mutants exhibiting increased tiller production. Meanwhile, a mutation frequency of 13.7% was obtained for the PGM gene with a CRISPR/Cas9 construct containing a single sgRNA. Among the PGM T0 mutants, six are heterozygous and one is homozygous for a 1-bp deletion in the target region with no apparent phenotypical alterations. We show that CRISPR/Cas9 system can generate targeted mutagenesis effectively and obtain targeted homozygous mutants in T0 generation in switchgrass, circumventing the need of inbreeding. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  17. Allelopathic Potential of Switchgrass ( Panicum virgatum L.) on Perennial Ryegrass ( Lolium perenne L.) and Alfalfa ( Medicago sativa L.)

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    Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

    2010-10-01

    This study investigated allelopathy and its chemical basis in nine switchgrass ( Panicum virgatum L.) accessions. Perennial ryegrass ( Lolium perenne L.) and alfalfa ( Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China’s Loess Plateau.

  18. Identification and characterization of microRNAs and their targets in the bioenergy plant switchgrass (Panicum virgatum).

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    Xie, Fuliang; Frazier, Taylor P; Zhang, Baohong

    2010-07-01

    MicroRNAs (miRNAs) are a class of non-coding small endogenous RNAs with lengths of approximately 22 nucleotides (nt) that have been shown to regulate gene expression at the post-transcriptional levels by targeting mRNAs for degradation or by inhibiting protein translation. Although thousands of miRNAs have been identified in many species, miRNAs have not yet been identified in switchgrass (Panicum virgatum), one of the most important bioenergy crops in the United States and around the world. In this study, we identified 121 potential switchgrass miRNAs, belonging to 44 families, using a well-defined comparative genome-based computational approach. We also identified miRNA clusters and antisense miRNAs in switchgrass expressed sequences tags. These identified miRNAs potentially target 839 protein-coding genes, which can act as transcription factors, and take part in multiple biological and metabolic processes including sucrose and fat metabolism, signal transduction, stress response, and plant development. Gene ontology (GO) analysis, based on these targets, showed that 527 biological processes were involved. Twenty-five of these processes were demonstrated to participate in the metabolism of carbon, glucose, starch, fatty acid, and lignin and in xylem formation. According to pathway enrichment analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG), 118 metabolism networks were found. These networks are involved in sucrose metabolism, fat metabolism, carbon fixation, hormone regulation, oxidative stress response, and the processing of other secondary metabolites.

  19. Identification and overexpression of a Knotted1-like transcription factor in switchgrass (Panicum virgatum L. for lignocellulosic feedstock improvement

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    Wegi eWuddineh

    2016-04-01

    Full Text Available High biomass production and wide adaptation has made switchgrass (Panicum virgatum L. an important candidate lignocellulosic bioenergy crop. One major limitation of this and other lignocellulosic feedstocks is the recalcitrance of complex carbohydrates to hydrolysis for conversion to biofuels. Lignin is the major contributor to recalcitrance as it limits the accessibility of cell wall carbohydrates to enzymatic breakdown into fermentable sugars. Therefore, genetic manipulation of the lignin biosynthesis pathway is one strategy to reduce recalcitrance. Here, we identified a switchgrass Knotted1 transcription factor, PvKN1, with the aim of genetically engineering switchgrass for reduced biomass recalcitrance for biofuel production. Gene expression of the endogenous PvKN1 gene was observed to be highest in young inflorescences and stems. Ectopic overexpression of PvKN1 in switchgrass altered growth, especially in early developmental stages. Transgenic lines had reduced expression of most lignin biosynthetic genes accompanied by a reduction in lignin content suggesting the involvement of PvKN1 in the broad regulation of the lignin biosynthesis pathway. Moreover, the reduced expression of the Gibberellin 20-oxidase (GA20ox gene in tandem with the increased expression of Gibberellin 2-oxidase (GA2ox genes in transgenic PvKN1 lines suggest that PvKN1 may exert regulatory effects via modulation of GA signalling. Furthermore, overexpression of PvKN1 altered the expression of cellulose and hemicellulose biosynthetic genes and increased sugar release efficiency in transgenic lines. Our results demonstrated that switchgrass PvKN1 is a putative ortholog of maize KN1 that is linked to plant lignification and cell wall and development traits as a major regulatory gene. Therefore, targeted overexpression of PvKN1 in bioenergy feedstocks may provide one feasible strategy for reducing biomass recalcitrance and simultaneously improving plant growth characteristics.

  20. Effect of Removal of Woody Biomass after Clearcutting and Intercropping Switchgrass (Panicum virgatum with Loblolly Pine (Pinus taeda on Rodent Diversity and Populations

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    Matthew M. Marshall

    2012-01-01

    Full Text Available Plant-based feedstocks have long been considered viable, potential sources for biofuels. However, concerns regarding production effects may outweigh gains like carbon savings. Additional information is needed to understand environmental effects of growing feedstocks, including effects on wildlife communities and populations. We used a randomized and replicated experimental design to examine initial effects of biofuel feedstock treatment options, including removal of woody biomass after clearcutting and intercropping switchgrass (Panicum virgatum, on rodents to 2 years post-treatment in regenerating pine plantations in North Carolina, USA. Rodent community composition did not change with switchgrass production or residual biomass removal treatments. Further, residual biomass removal had no influence on rodent population abundances. However, Peromyscus leucopus was found in the greatest abundance and had the greatest survival in treatments without switchgrass. In contrast, abundance of invasive Mus musculus was greatest in switchgrass treatments. Other native species, such as Sigmodon hispidus, were not influenced by the presence of switchgrass. Our results suggest that planting of switchgrass, but not biomass removal, had species-specific effects on rodents at least 2 years post-planting in an intensively managed southern pine system. Determining ecological mechanisms underlying our observed species associations with switchgrass will be integral for understanding long-term sustainability of biofuels production in southern pine forest.

  1. NEW STRAIN PRODUCERS OF BIOBUTANOL. III. METHODS OF INCREASED BUTANOL ACCUMULATION FROM BIOMASS OF SWITCHGRASS Panicum virgatum L.

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    Tigunova O. O.

    2015-08-01

    Full Text Available The aim of this work was to enlarge accumulation of butanol from switchgrass Panicum virgatum L. biomass using strains-producers obtained from grounds and silts of Kyiv lakes. The objects of the study were strains of C. acetobutylicum ІМВ B-7407 (IFBG C6H, Clostridium acetobutylicum IFBG C6H 5М and Clostridium tyrobutyricum IFBG C4B from the "Collections of microbial strains and lines of plants for food and agricultural biotechnology" of the Public Institution "Institute of Food Biotechnology and Genomics" of the National Academy of Sciences of Ukraine. Gas chromatography was used to determine the alcohol concentration at the stage of solvent synthesis. To determine the effect of butanol precursors during cultivation, butyric, lactic and acetic acids were used. Optimization of processing parameters, which was based on the needs of cultures, allowed us to increase the yield by 20 and 50% for the initial and mutant strain respectively. Using synthetic precursors (such as lactic, butyric and acetic acid during cultivation increased total concentration of butanol by 1.7 times. To optimize the process, a study was carried out using acetone- butyl grains. Using of acetone-butyl grains in concentrations up to 60% does not affect the synthesis of butanol by C. acetobutylicum IFBG C6H 5M. Increasing the concentration of grains led to decrease in accumulation of butanol. Almost double increase in accumulation of the target product (butanol was achieved using two-stage fermentation and/or precursors of synthesis. It was shown the possibility of using acetone-butyl grains in fermentation. As a result the mass fraction of the waste was reduced.

  2. Accuracy of Genomic Prediction in Switchgrass (Panicum virgatum L. Improved by Accounting for Linkage Disequilibrium

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    Guillaume P. Ramstein

    2016-04-01

    Full Text Available Switchgrass is a relatively high-yielding and environmentally sustainable biomass crop, but further genetic gains in biomass yield must be achieved to make it an economically viable bioenergy feedstock. Genomic selection (GS is an attractive technology to generate rapid genetic gains in switchgrass, and meet the goals of a substantial displacement of petroleum use with biofuels in the near future. In this study, we empirically assessed prediction procedures for genomic selection in two different populations, consisting of 137 and 110 half-sib families of switchgrass, tested in two locations in the United States for three agronomic traits: dry matter yield, plant height, and heading date. Marker data were produced for the families’ parents by exome capture sequencing, generating up to 141,030 polymorphic markers with available genomic-location and annotation information. We evaluated prediction procedures that varied not only by learning schemes and prediction models, but also by the way the data were preprocessed to account for redundancy in marker information. More complex genomic prediction procedures were generally not significantly more accurate than the simplest procedure, likely due to limited population sizes. Nevertheless, a highly significant gain in prediction accuracy was achieved by transforming the marker data through a marker correlation matrix. Our results suggest that marker-data transformations and, more generally, the account of linkage disequilibrium among markers, offer valuable opportunities for improving prediction procedures in GS. Some of the achieved prediction accuracies should motivate implementation of GS in switchgrass breeding programs.

  3. Alfalfa (Medicago sativa L. overseeding on mature switchgrass (Panicum virgatum L. stand: biomass yield and nutritive value after the establishment year

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    Alberto Mantino

    2016-08-01

    Full Text Available Perennial crops can positively act on the environment providing a better inter-annual protection of soil cover from water erosion, limiting soil fertility degradation, the risk of nutrient leaching and the exploitation of water for irrigation. Switchgrass (Panicum virgatum L., a warm-season grass native from North America, has been cultivated for decades as forage crop and only recently as bioenergy crop. Even if several studies reported a positive effect of nitrogen (N supply on switchgrass yield and quality, potential indirect and direct environmental risks (e.g., eutrophication and greenhouse gas emission are related to this practice. For this reason grass-legume intercropping can represent a sustainable practice able to increase biomass yield and quality, and at the same time to improve N use efficiency, soil structure and fertility. Based on this, the aim of this study was to evaluate the suitability of switchgrass to Mediterranean environment as forage crop and to improve biomass yield and its nutritional value by intercropping with alfalfa (Medicago sativa L. During spring 2013, in two switchgrass pure stands (varieties Alamo and Blackwell, respectively, alfalfa was established through direct seeding implementing a split-plot experimental design. Our first year results report a positive effect of the intercropping in increasing the total annual yield of the stand, of about 20% with respect to the pure switchgrass stand. However, the presence of alfalfa negatively affected switchgrass yield in the mixture. In both varieties, the crude protein content was higher in the mixture than in the pure switchgrass stands. Conversely, the neutral detergent fibre content in the mixture was lower than in pure switchgrass. Then, our results show that switchgrass-alfalfa intercropping leads to increase the profitability of grassland-based livestock production.

  4. Genome-size Variation in Switchgrass (Panicum virgatum: Flow Cytometry and Cytology Reveal Rampant Aneuploidy

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    Denise E. Costich

    2010-11-01

    Full Text Available Switchgrass ( L., a native perennial dominant of the prairies of North America, has been targeted as a model herbaceous species for biofeedstock development. A flow-cytometric survey of a core set of 11 primarily upland polyploid switchgrass accessions indicated that there was considerable variation in genome size within each accession, particularly at the octoploid (2 = 8 = 72 chromosome ploidy level. Highly variable chromosome counts in mitotic cell preparations indicated that aneuploidy was more common in octoploids (86.3% than tetraploids (23.2%. Furthermore, the incidence of hyper- versus hypoaneuploidy is equivalent in tetraploids. This is clearly not the case in octoploids, where close to 90% of the aneuploid counts are lower than the euploid number. Cytogenetic investigation using fluorescent in situ hybridization (FISH revealed an unexpected degree of variation in chromosome structure underlying the apparent genomic instability of this species. These results indicate that rapid advances in the breeding of polyploid biofuel feedstocks, based on the molecular-genetic dissection of biomass characteristics and yield, will be predicated on the continual improvement of our understanding of the cytogenetics of these species.

  5. Development of In Vitro Systems for Switchgrass (Panicum virgatum) - Final Report for 1992 to 2002

    Energy Technology Data Exchange (ETDEWEB)

    Conger, B.V.

    2003-01-16

    Our project began on July 1, 1992, with the objective of developing systems that could be used in biotechnological approaches to switchgrass improvement. Within six months after initiation of the project, we had worked out protocols in which plants could be regenerated from callus cultures through both organogenesis and somatic embryogenesis. Documentation for both modes of regeneration was provided in our progress reports and in publications. One thousand regenerated plants were established in the field during the first year. We found that Alamo (lowland type) was much more amenable to in vitro culture, and plants could be regenerated much more easily than from Cave-in-Rock (upland type). During the first three years of the project, we studied the influence of genotype, culture medium components, explant type, etc., on regeneration. As mentioned, we found that the lowland cultivars Alamo and Kanlow were much easier to regenerate than upland cultivars, such as Trailblazer, Blackwell, and Cave-in-Rock. For callus induction, we initially used mature caryopses, young leaf tissue, and portions of seedlings. We were successful in inducing callus and regenerating plants from all explants. Two other systems developed during the 4th to 6th year period of the project included multiple shoot formation initiated from germinated seedlings and regenerable suspension cultures. The latter were initiated from embryogenic calluses produced from in vitro developed inflorescences. An important factor for producing multiple shoots was the presence of thidiazuron in the medium. The shoots could be easily rooted and numerous plantlets produced. The last 3 to 4 years of the project focused on anther and microspore culture experiments to produce haploid plants and on genetic transformation. Although thousands of putative haploid plants were produced from a few anthers, they were very weak and difficult to keep alive. Chromosome counts revealed the gametic number in cells where it was

  6. Response surface studies that elucidate the role of infiltration conditions on Agrobacterium tumefaciens-mediated transient transgene expression in harvested switchgrass (Panicum virgatum)

    Energy Technology Data Exchange (ETDEWEB)

    VanderGheynst, J.S.; Guo, H.-Y.; Simmons, C.W. [Department of Biological and Agricultural Engineering, University of California, Davis, One Shields Avenue, Davis, CA 95616 (United States)

    2008-04-15

    Agrobacterium tumefaciens-mediated transient expression (agroinfiltration) experiments were performed in harvested switchgrass (Panicum virgatum) leaves to identify the effects of wounding by bead beating, surfactant concentration and vacuum application on in planta {beta}-glucuronidase expression and leaf decay. Expression was scored based on a consistent pattern of visual observations of histochemical staining over the leaf surface as might be observed in stable gene expression in switchgrass leaves. Assays on extracts from leaves were also performed to measure expression levels; however, these assays showed low expression levels, which may have been due to low recombinant protein recovery and decomposition in the leaf. Bead beating was successful for wounding the plant surface, but did not improve the consistency of expression based on histochemical staining observations. Surfactant was necessary for improving contact between the leaf surface and Agrobacterium suspension and consistently improved expression when vacuum application level was low (25 kPa). Increasing vacuum application from 25 to 5 kPa improved expression only when surfactant concentration was low. When a suspension of A. tumefaciens containing 1000 ppm Break-Thru surfactant was added to harvested leaves and 25 kPa vacuum applied, a fairly uniform expression was visualized across the leaf surface within 2-3 days of incubation, suggesting that agroinfiltration is a rapid tool for examining expression of transgenes in switchgrass leaves. (author)

  7. Overexpression of miR156 in switchgrass (Panicum virgatum L.) results in various morphological alterations and leads to improved biomass production

    Science.gov (United States)

    Fu, Chunxiang; Sunkar, Ramanjulu; Zhou, Chuanen; Shen, Hui; Zhang, Ji-Yi; Matts, Jessica; Wolf, Jennifer; Mann, David G J; Stewart, C Neal; Tang, Yuhong; Wang, Zeng-Yu

    2012-01-01

    Switchgrass (Panicum virgatum L.) has been developed into a dedicated herbaceous bioenergy crop. Biomass yield is a major target trait for genetic improvement of switchgrass. microRNAs have emerged as a prominent class of gene regulatory factors that has the potential to improve complex traits such as biomass yield. A miR156b precursor was overexpressed in switchgrass. The effects of miR156 overexpression on SQUAMOSA PROMOTER BINDING PROTEIN LIKE (SPL) genes were revealed by microarray and quantitative RT-PCR analyses. Morphological alterations, biomass yield, saccharification efficiency and forage digestibility of the transgenic plants were characterized. miR156 controls apical dominance and floral transition in switchgrass by suppressing its target SPL genes. Relatively low levels of miR156 overexpression were sufficient to increase biomass yield while producing plants with normal flowering time. Moderate levels of miR156 led to improved biomass but the plants were non-flowering. These two groups of plants produced 58%–101% more biomass yield compared with the control. However, high miR156 levels resulted in severely stunted growth. The degree of morphological alterations of the transgenic switchgrass depends on miR156 level. Compared with floral transition, a lower miR156 level is required to disrupt apical dominance. The improvement in biomass yield was mainly because of the increase in tiller number. Targeted overexpression of miR156 also improved solubilized sugar yield and forage digestibility, and offered an effective approach for transgene containment. PMID:22239253

  8. Selection and validation of reference genes for gene expression analysis in switchgrass (Panicum virgatum) using quantitative real-time RT-PCR.

    Science.gov (United States)

    Gimeno, Jacinta; Eattock, Nicholas; Van Deynze, Allen; Blumwald, Eduardo

    2014-01-01

    Switchgrass (Panicum virgatum) has received a lot of attention as a forage and bioenergy crop during the past few years. Gene expression studies are in progress to improve new traits and develop new cultivars. Quantitative real time PCR (qRT-PCR) has emerged as an important technique to study gene expression analysis. For accurate and reliable results, normalization of data with reference genes is essential. In this work, we evaluate the stability of expression of genes to use as reference for qRT-PCR in the grass P. virgatum. Eleven candidate reference genes, including eEF-1α, UBQ6, ACT12, TUB6, eIF-4a, GAPDH, SAMDC, TUA6, CYP5, U2AF, and FTSH4, were validated for qRT-PCR normalization in different plant tissues and under different stress conditions. The expression stability of these genes was verified by the use of two distinct algorithms, geNorm and NormFinder. Differences were observed after comparison of the ranking of the candidate reference genes identified by both programs but eEF-1α, eIF-4a, CYP5 and U2AF are ranked as the most stable genes in the samples sets under study. Both programs discard the use of SAMDC and TUA6 for normalization. Validation of the reference genes proposed by geNorm and NormFinder were performed by normalization of transcript abundance of a group of target genes in different samples. Results show similar expression patterns when the best reference genes selected by both programs were used but differences were detected in the transcript abundance of the target genes. Based on the above research, we recommend the use of different statistical algorithms to identify the best reference genes for expression data normalization. The best genes selected in this study will help to improve the quality of gene expression data in a wide variety of samples in switchgrass.

  9. Possibilities for Growing Switch-grass (Panicum virgatum as Second Generation Energy Crop in Dry-subhumid, Semiarid and Arid Regions of the Argentina

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    Silvia FALASCA

    2017-03-01

    Full Text Available Panicum virgatum (swich-grass is cultivated in some countries to obtain biomass used in the production of heat, fiber, electricity and second generation ethanol. Currently, in Argentina, this species is used for forage and as an ornamental. The aim of this work was to design an agroclimatic zoning model for swich-grass in Argentina, both for upland and lowland ecotypes, based on its bioclimatic requirements and employing a Geography Information System. The variables taken into consideration were: average temperature during growing period and reproductive period, frost free days and rainfall during growing season. This work demonstrated that an ample region of the country is agro-climatically suitable for the implantation of switch-grass in rainfed conditions or with complementary irrigation. The agroclimatic zoning for the upland ecotype shows that suitability reaches latitudes of up to 46ºS, while the lowland ecotype can be grown up to 40ºS. Thornthwaite's Moisture Index equal to zero was overlapped to the Argentinean agroclimatic zoning for upland and lowland types, to obtain the potential growing areas under dry-subhumid, semiarid to arid climates. The areas where switch-grass should be effectively tested are those categorized as optimal, very suitable, suitable, and very suitable/suitable with irrigation, located to the West of TMI equal to zero, which include dry-subhumid (0

  10. Switchgrass (Panicum virgatum L) flag leaf transcriptomes reveal molecular signatures of leaf development, senescence, and mineral dynamics

    Science.gov (United States)

    We provide the first comprehensive transcriptomic inspection of switchgrass flag leaf development. Flag leaves were collected from field grown switchgrass plants at five plant developmental stages: heading, anthesis, early and late seed development, and at physiological maturity and analyzed by RNA...

  11. Downregulation of the UDP-arabinomutase gene in switchgrass (Panicum virgatum L. results in increased cell wall lignin while reducing arabinose-glycans

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    Jonathan Duran Willis

    2016-10-01

    Full Text Available Switchgrass (Panicum virgatum L. is a C4 perennial prairie grass and a lignocellulosic biofuels feedstock. Saccharification and biofuel yields are inhibited by the plant cell wall’s natural recalcitrance against enzymatic degradation. Plant hemicellulose polysaccharides such as arabinoxylans structurally support and crosslink other cell wall polymers. Grasses have predominately Type II cell walls that are abundant in arabinoxylan, which comprise nearly 25% of aboveground biomass. A primary component of arabinoxylan synthesis is uridine diphosphate (UDP linked to arabinofuranose (Araf. A family of UDP-arabinopyranose mutase/reversible glycosylated polypeptides (UAM/RGPs catalyze the interconversion between UDP-arabinopyranose (UDP-Arap and UDP-Araf. In switchgrass we knocked down expression of the endogenous PvUAM1 gene via RNAi to investigate its role in cell wall recalcitrance in the feedstock. PvUAM1 encodes a switchgrass homolog of UDP-arabinose mutase, which converts UDP-Arap to UDP-Araf. Each transgenic line contained between one to at least seven T-DNA insertions, resulting in some cases, a 95% reduction of native PvUAM1 transcript in stem internodes. Transgenic plants had increased pigmentation in vascular tissues at nodes, but were otherwise morphologically similar to non-transgenics. There was decreased cell wall-associated arabinose in leaves and stems by over 50%, but there was an increase in cellulose in these organs. In addition, there was a commensurate change in arabinose side chain extension. Cell wall lignin composition was altered with a concurrent increase in lignin content and transcript abundance of lignin biosynthetic genes in mature tillers. Enzymatic saccharification efficiency was unchanged in the transgenic plants relative to the control, but had increased glucose in cell walls. The increased glucose detected in stems and leaves indicates that attenuation of PvUAM1 expression might have downstream effects on starch

  12. Growth promotion and colonization of switchgrass (Panicum virgatum cv. Alamo by bacterial endophyte Burkholderia phytofirmans strain PsJN

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    Kim Seonhwa

    2012-05-01

    Full Text Available Abstract Background Switchgrass is one of the most promising bioenergy crop candidates for the US. It gives relatively high biomass yield and can grow on marginal lands. However, its yields vary from year to year and from location to location. Thus it is imperative to develop a low input and sustainable switchgrass feedstock production system. One of the most feasible ways to increase biomass yields is to harness benefits of microbial endophytes. Results We demonstrate that one of the most studied plant growth promoting bacterial endophytes, Burkholderia phytofirmans strain PsJN, is able to colonize and significantly promote growth of switchgrass cv. Alamo under in vitro, growth chamber, and greenhouse conditions. In several in vitro experiments, the average fresh weight of PsJN-inoculated plants was approximately 50% higher than non-inoculated plants. When one-month-old seedlings were grown in a growth chamber for 30 days, the PsJN-inoculated Alamo plants had significantly higher shoot and root biomass compared to controls. Biomass yield (dry weight averaged from five experiments was 54.1% higher in the inoculated treatment compared to non-inoculated control. Similar results were obtained in greenhouse experiments with transplants grown in 4-gallon pots for two months. The inoculated plants exhibited more early tillers and persistent growth vigor with 48.6% higher biomass than controls. We also found that PsJN could significantly promote growth of switchgrass cv. Alamo under sub-optimal conditions. However, PsJN-mediated growth promotion in switchgrass is genotype specific. Conclusions Our results show B. phytofirmans strain PsJN significantly promotes growth of switchgrass cv. Alamo under different conditions, especially in the early growth stages leading to enhanced production of tillers. This phenomenon may benefit switchgrass establishment in the first year. Moreover, PsJN significantly stimulated growth of switchgrass cv. Alamo under sub

  13. Functional Characterization of NAC and MYB Transcription Factors Involved in Regulation of Biomass Production in Switchgrass (Panicum virgatum.

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    Ruiqin Zhong

    Full Text Available Switchgrass is a promising biofuel feedstock due to its high biomass production and low agronomic input requirements. Because the bulk of switchgrass biomass used for biofuel production is lignocellulosic secondary walls, studies on secondary wall biosynthesis and its transcriptional regulation are imperative for designing strategies for genetic improvement of biomass production in switchgrass. Here, we report the identification and functional characterization of a group of switchgrass transcription factors, including several NACs (PvSWNs and a MYB (PvMYB46A, for their involvement in regulating secondary wall biosynthesis. PvSWNs and PvMYB46A were found to be highly expressed in stems and their expression was closely associated with sclerenchyma cells. Overexpression of PvSWNs and PvMYB46A in Arabidopsis was shown to result in activation of the biosynthetic genes for cellulose, xylan and lignin and ectopic deposition of secondary walls in normally parenchymatous cells. Transactivation and complementation studies demonstrated that PvSWNs were able to activate the SNBE-driven GUS reporter gene and effectively rescue the secondary wall defects in the Arabidopsis snd1 nst1 double mutant, indicating that they are functional orthologs of Arabidopsis SWNs. Furthermore, we showed that PvMYB46A could activate the SMRE-driven GUS reporter gene and complement the Arabidopsis myb46 myb83 double mutant, suggesting that it is a functional ortholog of Arabidopsis MYB46/MYB83. Together, these results indicate that PvSWNs and PvMYB46A are transcriptional switches involved in regulating secondary wall biosynthesis, which provides molecular tools for genetic manipulation of biomass production in switchgrass.

  14. Functional Characterization of NAC and MYB Transcription Factors Involved in Regulation of Biomass Production in Switchgrass (Panicum virgatum).

    Science.gov (United States)

    Zhong, Ruiqin; Yuan, Youxi; Spiekerman, John J; Guley, Joshua T; Egbosiuba, Janefrances C; Ye, Zheng-Hua

    2015-01-01

    Switchgrass is a promising biofuel feedstock due to its high biomass production and low agronomic input requirements. Because the bulk of switchgrass biomass used for biofuel production is lignocellulosic secondary walls, studies on secondary wall biosynthesis and its transcriptional regulation are imperative for designing strategies for genetic improvement of biomass production in switchgrass. Here, we report the identification and functional characterization of a group of switchgrass transcription factors, including several NACs (PvSWNs) and a MYB (PvMYB46A), for their involvement in regulating secondary wall biosynthesis. PvSWNs and PvMYB46A were found to be highly expressed in stems and their expression was closely associated with sclerenchyma cells. Overexpression of PvSWNs and PvMYB46A in Arabidopsis was shown to result in activation of the biosynthetic genes for cellulose, xylan and lignin and ectopic deposition of secondary walls in normally parenchymatous cells. Transactivation and complementation studies demonstrated that PvSWNs were able to activate the SNBE-driven GUS reporter gene and effectively rescue the secondary wall defects in the Arabidopsis snd1 nst1 double mutant, indicating that they are functional orthologs of Arabidopsis SWNs. Furthermore, we showed that PvMYB46A could activate the SMRE-driven GUS reporter gene and complement the Arabidopsis myb46 myb83 double mutant, suggesting that it is a functional ortholog of Arabidopsis MYB46/MYB83. Together, these results indicate that PvSWNs and PvMYB46A are transcriptional switches involved in regulating secondary wall biosynthesis, which provides molecular tools for genetic manipulation of biomass production in switchgrass.

  15. Switchgrass (Panicum virgatum fermentation by Clostridium thermocellum and Clostridium saccharoperbutylacetonicum sequential culture in a continuous flow reactor

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    Noelia M. Elía

    2016-01-01

    Full Text Available The study was conducted to evaluate fermentation by Clostridium thermocellum and C. saccharoperbutylacetonicum in a continuous-flow, high-solids reactor. Liquid medium was continuously flowed through switchgrass (2 mm particle size at one of three flow rates: 83.33 mL h−1 (2 L d−1, 41.66 mL h−1 (1 L d−1, and 20.833 mL h−1 (0.5 L d−1. The cellulolytic phase was initiated by culturing C. thermocellum (63 °C, 24 h. The temperature was decreased (35 and C. saccharoperbutylacetonicum was inoculated. When metabolism decreased (96 h, the temperature was increased (63 °C; 24 h to permit cellulosome production by C. thermocellum. The C. saccharoperbutylacetonicum was re-inoculated and the temperature returned to 35°C. The average gross production over 9 d was 1480 mg total acids (formic, acetic lactic butyric, 207 mg total solvents (acetone, butanol, ethanol, and average dry matter disappearance was 2.8 g from 25 g non-pretreated switchgrass. There was no effect of flow rate on the product formation. These results indicate that C. thermocellum can survive and produce cellulases with C. saccharoperbutylacetonicumin a continuous-flow, high-solids reactor temperature with temperature cycling.

  16. Model optimization of cadmium and accumulation in switchgrass (Panicum virgatum L.): potential use for ecological phytoremediation in Cd-contaminated soils.

    Science.gov (United States)

    Wang, Quanzhen; Gu, Muyu; Ma, Xiaomin; Zhang, Hongjuan; Wang, Yafang; Cui, Jian; Gao, Wei; Gui, Jing

    2015-11-01

    Soil pollution with heavy metals is an increasingly serious threat to the environment, food security, and human health. Therefore, it is urgent to develop economic and highly efficient soil restoration technology for environmental improvement; phytoremediation is an option that is safe, has low cost, and is environmentally friendly. However, in selecting hyperaccumulators or tolerant plants, theories and operation technologies for optimal restoration should be satisfied. In this study, the switchgrass growth response and performance of phytoextraction under the coupling effect of Cd and pH were investigated by evaluating seed germination, seedling growth, and the Cd content in the plant to evaluate the potential use of switchgrass as a phytoremediation plant in cadmium contaminated soil. This study conducted three sets of independent experiments with five levels of Cd concentrations, including two orthogonal matrix designs of combining Cd with pH values. The results showed that switchgrass was germinated well under all treatments (Cd concentration of 0-500 μM), but the seedling growth was significantly affected by Cd and pH, as shown by multivariate regression analyses. Hormesis was found during the growth of switchgrass plants exposed to low Cd concentrations under hydroponic conditions, and switchgrass plants were capable of developing with a Cd concentration of 100-175 μM and pH of 4.1-5.9. Mild acidic conditions can enhance the ability of Cd to accumulate in switchgrass. Switchgrass was moderately tolerant to Cd and may be used as a phytoremediation plant for Cd-contaminated soils in the future. Our results also suggest that hormetic effects should be taken into consideration in the phytoremediation of Cd-contaminated soils. We discuss the physiological and biochemical mechanisms contributing to the effective application of the plant for the phytoremediation of Cd-contaminated soils.

  17. Distribution models for Panicum virgatum (Poaceae) reveal an expanded range in present and future climate regimes in the northeastern United States.

    Science.gov (United States)

    Ahrens, Collin W; Meyer, Thomas H; Auer, Carol A

    2014-11-01

    Expanded area cultivated with the bioenergy crop Panicum virgatum (switchgrass) could alter the genetics of native populations through gene flow, so understanding current and future species distribution is a first step toward estimating ecological impacts. We surveyed switchgrass distribution in the northeastern United States and generated statistical models to address hypotheses about current distribution relative to historical records and responses to climate change. Surveys were conducted on 1600 km of road verges along environmental gradients. Switchgrass abundance became the training data for two multivariate generalized linear models that generated maps representing the probability of switchgrass in road verges. Models were evaluated and the superior model was used with variables from three climate change scenarios for 2050 and 2099. Switchgrass populations were found in 41% of roadside plots and up to 188 km from the coast. The environmental variables temperature, urban areas, and sandy soils were positively correlated with switchgrass presence, while elevation, soil pH, and distance to the coast were negatively correlated. The model without spatial autocorrelation performed better. Models and maps incorporating climate change predictions showed a sharp northward shift in suitable habitat. Switchgrass populations in the northeastern United States occur on inland road verges, supporting the idea that species distribution has expanded relative to historical descriptions of a restricted coastal habitat. The optimal model showed that mean temperature, elevation, and urban development were important in switchgrass distribution today, and climate change will increase suitable habitat for future bioenergy production and wild populations. © 2014 Botanical Society of America, Inc.

  18. Understanding changes in lignin of Panicum virgatum and Eucalyptus globulus as a function of ionic liquid pretreatment.

    Science.gov (United States)

    Varanasi, Patanjali; Singh, Priyanka; Arora, Rohit; Adams, Paul D; Auer, Manfred; Simmons, Blake A; Singh, Seema

    2012-12-01

    Ionic liquids (ILs) have shown great potential for the reduction of lignin in biomass after pretreatment. Although dilute acid and base pretreatments have been shown to result in pretreated biomass with substantially different lignin composition, there is scarce information on the composition of lignin of IL pretreated biomass. In this work, temperature dependent compositional changes in lignin after IL pretreatment were studied to develop a mechanistic understanding of the process. Panicum virgatum and Eucalyptus globulus were pretreated with 1-ethyl-3-methylimidazolium acetate ([C(2)mim][OAc]). Measurement of syringyl and guaiacyl ratio using pyrolysis-GC/MS and Kamlet-Taft properties of [C(2)mim][OAc] at 120 °C and 160 °C strongly suggest two different modes of IL pretreatment. Preferential breakdown of S-lignin in both eucalyptus and switchgrass at high pretreatment temperature (160 °C) and breakdown of G-lignin for eucalyptus and no preferential break down of either S- or G-lignin in switchgrass was observed at lower pretreatment temperatures (120 °C). Copyright © 2012. Published by Elsevier Ltd.

  19. Production and supply logistics of switchgrass as an energy feedstock

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) is a warm-season (C4), perennial grass that is native to the tallgrass ecoregion of North America (Figure 1). Historically, switchgrass has been used for summer forage, hay, ensiling, or in conservation plantings. At the end of the 20th century, switchgrass was de...

  20. Sustainable Production of Switchgrass for Biomass Energy

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) is a C4 grass native to the North American tallgrass prairies, which historically extended from Mexico to Canada. It is the model perennial warm-season grass for biomass energy. USDA-ARS in Lincoln, NE has studied switchgrass continuously since 1936. Plot-scale rese...

  1. Registration of 'liberty' switchgrass

    Science.gov (United States)

    ‘Liberty’ switchgrass (Panicum virgatum L.) is a lowland type cultivar that is adapted to USDA Plant Hardiness Zones 4, 5, and 6 in the Great Plains and Midwest, USA east of 100o W. Longitude and potentially other regions where it has not been tested to date. It was developed for use as a perennia...

  2. Phytoextraction of contaminated urban soils by Panicum virgatum L. enhanced with application of a plant growth regulator (BAP) and citric acid.

    Science.gov (United States)

    Aderholt, Matthew; Vogelien, Dale L; Koether, Marina; Greipsson, Sigurdur

    2017-05-01

    Lead (Pb) contamination in soil represents a threat to human health. Phytoextraction has gained attention as a potential alternative to traditional remediation methods because of lower cost and minimal soil disruption. The North American native switchgrass (Panicum virgatum L.) was targeted due to its ability to produce high biomass and grow across a variety of ecozones. In this study switchgrass was chemically enhanced with applications of the soil-fungicide benomyl, chelates (EDTA and citric acid), and PGR to optimize phytoextraction of Pb and zinc (Zn) from contaminated urban soils in Atlanta, GA. Exogenous application of two plant hormones was compared in multiple concentrations to determine effects on switchgrass growth: indole-3-acetic acid (IAA), and Gibberellic Acid (GA 3 ), and one PGR benzylaminopurine (BAP), The PGR BAP (1.0 μM) was found to generate a 48% increase in biomass compared to Control plants. Chemical application of citric acid, EDTA, benomyl, and BAP were tested separately and in combination in a pot experiment in an environmentally controlled greenhouse to determine the efficacy of phtyoextraction by switchgrass. Soil acidification by citric acid application resulted in highest level of aluminum (Al) and iron (Fe) in plants foliage resulting in severe phytotoxic effects. Total Pb phytoextraction was significantly highest in plants treated with combined chemical application of B + C and B + C + H. Suppression of AMF activities by benomyl application significantly increased concentrations of Al and Fe in roots. Application of benomyl reduced AMF colonization but was also shown to dramatically increase levels of septa fungi infection as compared to Control plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Economics of intercropping loblolly pine and switchgrass for bioenergy markets in the southeastern United States

    Science.gov (United States)

    Andres Susaeta; Janaki Alavalapati Pankaj Lal; D. Evan Mercer; Douglas Carter

    2012-01-01

    Abstract The main objective of this study was to assess the economics of alley cropping of loblolly pine (Pinus taeda L.) and switchgrass (Panicum virgatum) in the southern United States. Assuming a price range of switchgrass between $15 and $50 Mg-1 and yield of 12 Mg ha-1 year-1, we investigated the effect of switchgrass production on the optimal forest management...

  4. Genetic Transformation of Switchgrass

    Science.gov (United States)

    Xi, Yajun; Ge, Yaxin; Wang, Zeng-Yu

    Switchgrass (Panicum virgatum L.) is a highly productive warm-season C4 species that is being developed into a dedicated biofuel crop. This chapter describes a protocol that allows the generation of transgenic switchgrass plants by Agrobacterium tumefaciens-mediated transformation. Embryogenic calluses induced from caryopses or inflorescences were used as explants for inoculation with A. tumefaciens strain EHA105. Hygromycin phosphotransferase gene (hph) was used as the selectable marker and hygromycin was used as the selection agent. Calluses resistant to hygromycin were obtained after 5-6 weeks of selection. Soil-grown switchgrass plants were regenerated about 6 months after callus induction and Agrobacterium-mediated transformation.

  5. The Genetics of Biofuel Traits in Panicum Grasses: Developing a Model System with Diploid Panicum Hallii

    Energy Technology Data Exchange (ETDEWEB)

    Juenger, Thomas [Univ. of Texas, Austin, TX (United States). Dept. of Integrative Biology; Wolfrum, Ed [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-07-31

    Our DOE funded project focused on characterizing natural variation in C4 perennial grasses including switchgrass (Panicum virgatum) and Hall’s panicgrass (Panicum hallii). The main theme of our project was to better understand traits linked with plant performance and that impact the utility of plant biomass as a biofuel feedstock. In addition, our project developed tools and resources for studying genetic variation in Panicum hallii. Our project successfully screened both Panicum virgatum and Panicum hallii diverse natural collections for a host of phenotypes, developed genetic mapping populations for both species, completed genetic mapping for biofuel related traits, and helped in the development of genomic resources of Panicum hallii. Together, these studies have improved our understanding of the role of genetic and environmental factors in impacting plant performance. This information, along with new tools, will help foster the improvement of perennial grasses for feedstock applications.

  6. Gas exchange and stand-level estimates of water use and gross primary productivity in an experimental pine and switchgrass intercrop forestry system on the Lower Coastal Plain of North Carolina, U.S.A

    Science.gov (United States)

    Janine M. Albaugha; Jean-Christophe Domeca; Chris A. Maier; Eric B. Sucre; Zakiya H. Leggett; John S. King

    2014-01-01

    Despite growing interest in using switchgrass (Panicum virgatum L.) as a biofuel, there are limiteddata on the physiology of this species and its effect on stand water use and carbon (C) assimilationwhen grown as a forest intercrop for bioenergy. Therefore, we quantified gas exchange rates of switch-grass within intercropped plots and in pure switchgrass plots during...

  7. Impact of harvest time and switchgrass cultivar on sugar release through enzymatic hydrolysis

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) is a native North American prairie grass being developed for bioenergy production in the central and eastern USA. The objective of this study was to identify the impacts harvest time and switchgrass cultivar had on sugar release variables determined through enzymat...

  8. Etude de production et de caracterisation de biocharbons de panic erige (Panicum virgatum L.) obtenus par pyrolyse

    Science.gov (United States)

    Pilon, Guillaume

    This research aimed at the production of biomass char under pyrolytic conditions, targeting biochar as soil amendment, while also considering its application as biocoal, either for bioenergy or subsequent upgrading. The production of biomass char was performed using two bench-scale, batch-type, fixed-bed reactors, each with an operating capacity of 1 and 25 gw.b. /batch, respectively. Switchgrass (Panicum virgatum) has been used for the tests. Production conditions studied implied temperatures of 300, 400 and 500 °C with short residence times (2.5 and 5 min). As well, the effect of using CO2 as vector gas has been compared to a common inert environment of N2. The effects of the previously mentioned parameters were correlated with some important physicochemical characteristics of biomass char. Analyses were also performed on complementary pyrolytic products (bio-oil and gas). The biomass char extraction was performed using a Soxhlet and dichloromethane was used as extracting solvent. The extracts were then characterized by GC-MS thus allowing the identification of several compounds. Specific pyrolysis conditions used at 300 °C - N2 with the 1 g/batch reactor, such as high heating rates as well as high convection conditions, presented advantegeous biomass char yields and properties, and, possible torrefaction process productivity improvement (in comparison to reported literature, such as Gilbert et al. [2009]). The char extracts as well as the bio-oils analysis (also performed using GC-MS), all generated from the 25 g/batch reactor, showed major differences among the compounds obtained from the CO2 and N2 environments, respectively. Several compounds observed in the char extracts appeared less concentrated in the CO2 environment vs N2, for the same reaction temperatures. As an example, at 400 °C, furfural was found only in char extracts from N2 environment as compared to the CO2 environment. Among all studied conditions (for both reactors), only naphthalene and

  9. Impact of harvest time and cultivar on conversion of switchgrass to bio-oils via fast pyrolysis

    Science.gov (United States)

    The study of the effects of harvest time on switchgrass (Panicum virgatum L.) biomass and bioenergy production reported herein is the final part complementing two prior studies reporting on the harvest of six switchgrass cultivars grown at three northern United States locations over three years, har...

  10. Utility of remote sensing-based surface energy balance models to track water stress in rain-fed switchgrass under dry and wet conditions

    Science.gov (United States)

    The ability of remote sensing-based surface energy balance (SEB) models to track water stress in rain-fed switchgrass has not been explored yet. In this paper, the theoretical framework of crop water stress index (CWSI) was utilized to estimate CWSI in rain-fed switchgrass (Panicum virgatum L.) usin...

  11. Environmental sustainability of intercropping switchgrass in a loblolly pine forest

    Science.gov (United States)

    George Chescheir; Francois Birgand; Mohamed Youssef; Jami Nettles; Devendra Amatya

    2016-01-01

    A multi-institutional watershed study has been conducted since 2010 to quantify the environmental sustainability of planting switchgrass (Panicum virgatum L.) between wide rows of loblolly pine (Pinus taeda L.). The hypothesized advantage of this intercropping system is the production of biofuel feedstock to provide additional...

  12. Field productivities of Switchgrass for conversion to sugars and ethanol

    Science.gov (United States)

    Switchgrass (SG, Panicum virgatum) is a warm season perennial grass being developed as a dedicated bioenergy crop. The Agricultural Research Service has recently released a new cultivar of SG named Liberty, which is a cross between Summer and Kanlow cultivars. In prior studies Liberty grown on 4 sit...

  13. Use of Switchgrass as a Nursery Container Substrate

    Science.gov (United States)

    Pine (Pinus taeda L.) bark is the primary component of Nursery container crops in the eastern U.S. Shortages in pine bark prompted investigation of alternative substrates. The objective of this research was to determine if ground switchgrass (Panicum virgatum L.) could be used for short production...

  14. Generation of octoploid switchgrass by seedling treatment with mitotic inhibitors

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) exists as multiple cytotypes with octaploid and tetraploid populations occupying distinct, overlapping ranges. These cytotypes tend to show differences in adaptation, yield potential, and other characters, but the specific role of whole genome duplication is not cl...

  15. The WRKY transcription factor family and senescence in switchgrass

    Science.gov (United States)

    Background: Early aerial senescence in switchgrass (Panicum virgatum) can significantly limit biomass yields. WRKY transcription factors that can regulate senescence could be used to reprogram senescence and enhance biomass yields. Methods: All potential WRKY genes present in the version 1.0 of the...

  16. Evaluation of intercropped switchgrass establishment under a range of experimental site preparation treatments in a forested setting on the Lower Coastal Plain of North Carolina, U.S.A

    Science.gov (United States)

    Janine M. Albaugh; Eric B. Sucre; Zakiya H. Leggett; Jean-Christophe Domec; John S. King

    2012-01-01

    There is growing interest in using switchgrass (Panicum virgatum L.) as a biofuel crop and for its potential to sequester carbon. However, there are limited data on the establishment success of this species when grown as a forest intercrop in coastal plain settings of the U.S. Southeast. Therefore, we studied establishment success of switchgrass...

  17. Genomic Characterization of Interspecific Hybrids and an Admixture Population Derived from Panicum amarum × P. virgatum

    Directory of Open Access Journals (Sweden)

    Christopher Heffelfinger

    2015-07-01

    Full Text Available Switchgrass ( L. and its relatives are regarded as top bioenergy crop candidates; however, one critical barrier is the introduction of useful genetic diversity and the development of new cultivars and hybrids. Combining genomes from related cultivars and species provides an opportunity to introduce new traits. In switchgrass, a breeding advantage would be achieved by combining the genomes of intervarietal ecotypes or interspecific hybrids. The recovery of wide crosses, however, is often tedious and may involve complicated embryo rescue and numerous backcrosses. Here, we demonstrate a straightforward approach to wide crosses involving the use of a selectable transgene for recovery of interspecific [ cv. Alamo × Ell var or Atlantic Coastal Panicgrass (ACP] F hybrids followed by backcrossing to generate a nontransgenic admixture population. A nontransgenic herbicide-sensitive (HbS admixture population of 83 FBC progeny was analyzed by genotyping-by-sequencing (GBS to characterize local ancestry, parental contribution, and patterns of recombination. These results demonstrate a widely applicable breeding strategy that makes use of transgenic selectable resistance to identify and recover true hybrids.

  18. Water quality effects of switchgrass intercropping on pine forest in Coastal North Carolina.

    Science.gov (United States)

    Augustine Muwamba; Devendra Amatya; George M Chescheir; Jamie Nettles; Timothy Appelboom; Herbert Ssegane; Ernest Tollner; Mohamed Youssef; Francois Birgand; R. Wayne Skaggs; Shiying Tian

    2017-01-01

    Interplanting a cellulosic bioenergy crop (switchgrass, Panicum virgatum L.) between loblolly pine (Pinus taeda L.) rows could potentially provide a sustainable source of bio-feedstock without competing for land currently in food production. The objectives of this study were to: (1) quantify the concentrations and loads of drainage water nitrogen (N) and phosphorus (...

  19. Quantitative trait loci mapping for flowering time in a switchgrass pseudo-F2 population

    Science.gov (United States)

    Flowering is an important developmental event in switchgrass (Panicum virgatum) because the onset of flowering causes the cessation of vegetative growth and biomass accumulation. The objective of this study was to generate a linkage map using single nucleotide polymorphism (SNP) markers to identify ...

  20. Chemical compositions of four switchgrass populations

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Jinhua; Hu, Zhoujian; Pu, Yunqiao [School of Chemistry and Biochemistry, Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Charles Brummer, E. [Institute of Plant Breeding, Center for Applied Genetic Technologies Crop and Soil Sciences Department, University of Georgia, Athens, GA 30602 (United States); Ragauskas, Arthur J. [School of Chemistry and Biochemistry, Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Forest Products and Chemical Engineering, Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden)

    2010-01-15

    Four populations of switchgrass (Alamo, GA993, GA992, Kanlow), Panicum virgatum L., were studied for the difference of their chemical constituents. The extractives, Klason lignin, and carbohydrates compositions of the stem portion of these switchgrass populations were determined by gas chromatography mass spectroscopy (GC-MS) and high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) respectively. Ball milled grass lignin (BMGL) was isolated and analyzed by NMR spectroscopy. The results demonstrated that the chemical compositions of four switchgrass populations were similar with the exception of the lignin content and chemical composition of extractives. The results of quantitative {sup 13}C NMR spectroscopy indicated that switchgrass lignin consisted of p-hydroxylphenyl, guaiacyl, and syringyl units in an average ratio of 26:42:32 and incorporated with p-coumaric acid and ferulic acid at a level of approximately 0.20 per aromatic ring. The lignin structure of four switchgrass cultivars was comparable. (author)

  1. Greenhouse gas fluxes and root productivity in a switchgrass and loblolly pine intercropping system for bioenergy production

    Science.gov (United States)

    Paliza Shrestha; John R. Seiler; Brian D. Strahm; Eric B. Sucre; Zakiya H. Leggett

    2015-01-01

    This study is part of a larger collaborative effort to determine the overall environmental sustainability of intercropping pine (Pinus taeda L.) and switchgrass (Panicum virgatum L.), both of which are promising feedstock for bioenergy production in the Lower Coastal Plain in North Carolina.

  2. Production of polyhydroxybutyrate in switchgrass

    Science.gov (United States)

    Somleva, Mariya N.; Snell, Kristi D.; Beaulieu, Julie; Peoples, Oliver P.; Garrison, Bradley; Patterson, Nii

    2013-07-16

    Transgenic plants, plant material, and plant cells for synthesis of polyhydroxyalkanoates, preferably poly(3-hydroxybutyrate) (also referred to a as PHB) are provided. Preferred plants that can be genetically engineered to produce PHB include plants that do not normally produce storage products such as oils and carbohydrates, and plants that have a C.sub.4 NAD-malic enzyme photosynthetic pathway. Such plants also advantageously produce lignocellulosic biomass that can be converted into biofuels. An exemplary plant that can be genetically engineered to produce PHB and produce lignocellulosic biomass is switchgrass, Panicum virgatum L. A preferred cultivar of switchgrass is Alamo. Other suitable cultivars of switchgrass include but are not limited to Blackwell, Kanlow, Nebraska 28, Pathfinder, Cave-in-Rock, Shelter and Trailblazer.

  3. ESTABLISHMENT AND EVALUATION OF SWITCHGRASS ON RECLAIMED MINE SOIL [English

    Energy Technology Data Exchange (ETDEWEB)

    Lang, David; Shankle, Brandon; Oswalt, Ernest; Duckworth, Jeremy; Sanborn, Judd; Buell, Rebecca; Roberson, Bill

    2010-06-30

    Switchgrass (Panicum virgatum L.) is a native warm season perennial grass that has productive potential of up to 20 Mg ha-1 of biomass and it persists for decades when harvested once per year. Switchgrass provides excellent ground cover and soil stabilization once established and contributes to soil sequestration of new carbon. Slow establishment on newly reclaimed soil, however, provides for significant erosive opportunities thereby requiring initial soil stabilization with a cover crop. Several planting options were evaluated on two topsoil substitute soils. The planting options included: 1) an existing stand of bermudagrass (Cynodon dactylon L.) that was killed with glyphosate followed by disking in red oxidized topsoil substitute and prime farmland topsoil respread in 2007, 2) red oxidized topsoil substitute was seeded directly with switchgrass, 3) browntop millet (Panicum ramosum) was established with switchgrass, 4) or switchgrass was established in senescing browntop millet or wheat without tillage. Switchgrass was successfully established into a bermudagrass sod that had been killed with herbicides and disked as well as into a senescing stand of browntop millet or wheat. Significant soil erosion occurred on the disked area in 2008 leading to considerable repair work followed by planting wheat. Disked areas that did not erode had an excellent stand of switchgrass with 23.3 plants m-2 in November, 2008. Eroded areas replanted in April, 2009 into senescing wheat had 46 plants m-2 by July, 2009. The area planted directly into newly respread soil in May, 2009 was eroded severely by a 75 mm thunderstorm and was repaired, disked and replanted to switchgrass and browntop millet. Switchgrass seeded with browntop millet had a sparse switchgrass stand and was replanted to switchgrass in August, 2009. Rainfall volumes from August, 2009 to October, 2009 totaled 750 mm, but new erosion damage in areas successfully planted to switchgrass has been minimal.

  4. Plant community and white-tailed deer nutritional carrying capacity response to intercropping switchgrass in loblolly pine plantations

    Science.gov (United States)

    Greene, Ethan Jacob

    Switchgrass (Panicum virgatum L.) is a cellulosic feedstock for alternative energy production that could grow well between planted pines (Pinus spp.). Southeastern planted pine occupies 15.8 million hectares and thus, switchgrass intercropping could affect biodiversity if broadly implemented. Therefore, I evaluated effects of intercropping switchgrass in loblolly pine (P. taeda L.) plantations on plant community diversity, plant biomass production, and white-tailed deer (Odocoileus virginianus Zimmerman) nutritional carrying capacity. In a randomized complete block design, I assigned three treatments (switchgrass intercropped, switchgrass monoculture, and a "control" of traditional pine management) to 4 replicates of 10-ha experimental units in Kemper County, Mississippi during 2014-2015. I detected 246 different plant species. Switchgrass intercropping reduced plant species richness and diversity but maintained evenness. I observed reduced forb and high-use deer forage biomass but only in intercropped alleys (interbeds). Soil micronutrient interactions affected forage protein of deer plants. White-tailed deer nutritional carrying capacity remained unaffected.

  5. VOC Emissions from the Potential Biofuel Crop, Switchgrass

    Science.gov (United States)

    Graus, M.; Eller, A. S.; Fall, R.; Gilman, J. B.; Kuster, W. C.; de Gouw, J. A.; Qian, Y.; Sekimoto, K.; Monson, R. K.; Warneke, C.

    2010-12-01

    Volatile organic compound (VOC) emission rates during the growth and simulated harvest phases were determined for three different cultivars of switchgrass (Panicum virgatum) using laboratory chamber measurements. Switchgrass is a candidate for use in second-generation (cellulosic) ethanol production and the acerage dedicated to its growth in the USA has already increased during the past decade. We estimate that the yearly emissions from switchgrass plantations, including both the growth and harvest phases, will be on the order of 3 kg C ha-1 methanol, 1 kg C ha-1 acetaldehyde, 1 kg C ha-1 acetone, 0.9 kg C ha-1 monoterpenes, 0.5 kg C ha-1 isoprene + 1-penten-3-ol, 0.2 kg C ha-1 hexenals, and 0.1 kg C ha-1 hexenols. These emission rates are lower than those expected from Eucalyptus or Poplar plantations, which are other potential biofuel crops and have significantly higher VOC emissions.

  6. Simulating Potential Switchgrass Production in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, Allison M.; Izaurralde, Roberto C.; West, T. O.; Parrish, David J.; Tyler, Donald D.; Williams, Jimmy R.

    2009-12-31

    Using results from field trials of switchgrass (Panicum virgatum L.) in the United States, the EPIC (Environmental Policy Integrated Climate) process-level agroecosystem model was calibrated, validated, and applied to simulate potential productivity of switchgrass for use as a biofuel feedstock. The model was calibrated with a regional study of 10-yr switchgrass field trials and subsequently tested against a separate compiled dataset of field trials from across the eastern half of the country. An application of the model in a national database using 8-digit watersheds as the primary modeling unit produces 30-yr average switchgrass yield estimates that can be aggregated to 18 major watersheds. The model projects average annual switchgrass productivity of greater than 7 Mg ha-1 in the Upper Mississippi, Lower Mississippi, and Ohio watersheds. The major factors limiting simulated production vary by region; low precipitation is the primary limiting factor across the western half of the country, while moderately acidic soils limit yields on lands east of the Mississippi River. Average projected switchgrass production on all crop land in the continental US is 5.6 Mg ha-1. At this level of productivity, 28.6 million hectares of crop land would be required to produce the 16 billion gallons of cellulosic ethanol called for by 2022 in the 2007 Energy Independence and Security Act. The model described here can be applied as a tool to inform the land-use and environmental consequences of switchgrass production.

  7. Exploring the switchgrass transcriptome using second-generation sequencing technology.

    Directory of Open Access Journals (Sweden)

    Yixing Wang

    Full Text Available BACKGROUND: Switchgrass (Panicum virgatum L. is a C4 perennial grass and widely popular as an important bioenergy crop. To accelerate the pace of developing high yielding switchgrass cultivars adapted to diverse environmental niches, the generation of genomic resources for this plant is necessary. The large genome size and polyploid nature of switchgrass makes whole genome sequencing a daunting task even with current technologies. Exploring the transcriptional landscape using next generation sequencing technologies provides a viable alternative to whole genome sequencing in switchgrass. PRINCIPAL FINDINGS: Switchgrass cDNA libraries from germinating seedlings, emerging tillers, flowers, and dormant seeds were sequenced using Roche 454 GS-FLX Titanium technology, generating 980,000 reads with an average read length of 367 bp. De novo assembly generated 243,600 contigs with an average length of 535 bp. Using the foxtail millet genome as a reference greatly improved the assembly and annotation of switchgrass ESTs. Comparative analysis of the 454-derived switchgrass EST reads with other sequenced monocots including Brachypodium, sorghum, rice and maize indicated a 70-80% overlap. RPKM analysis demonstrated unique transcriptional signatures of the four tissues analyzed in this study. More than 24,000 ESTs were identified in the dormant seed library. In silico analysis indicated that there are more than 2000 EST-SSRs in this collection. Expression of several orphan ESTs was confirmed by RT-PCR. SIGNIFICANCE: We estimate that about 90% of the switchgrass gene space has been covered in this analysis. This study nearly doubles the amount of EST information for switchgrass currently in the public domain. The celerity and economical nature of second-generation sequencing technologies provide an in-depth view of the gene space of complex genomes like switchgrass. Sequence analysis of closely related members of the NAD(+-malic enzyme type C4 grasses such as

  8. Switching to switchgrass: Pathways and consequences of bioenergy switchgrass entering the Midwestern landscape

    Science.gov (United States)

    Krohn, Brian

    The US has the ambitious goal of producing 60 billion liters of cellulosic biofuel by 2022. Researchers and US Federal Agencies have identified switchgrass (Panicum virgatum L.) as a potential feedstock for next generation biofuels to help meet this goal because of its excellent agronomic and environmental characteristics. With national policy supporting the development of a switchgrass to bioenergy industry two key questions arise: 1) Under what economic and political conditions will switchgrass enter the landscape? 2) Where on the landscape will switchgrass be cultivated given varying economic and political conditions? The goal of this dissertation is to answer these questions by analyzing the adoption of switchgrass across the upper Midwestern US at a high spatial resolution (30m) under varying economic conditions. In the first chapter, I model switchgrass yields at a high resolution and find considerable variability in switchgrass yields across space, scale, time, and nitrogen management. Then in the second chapter, I use the spatial results from chapter one to challenge the assumption that low-input (unmanaged) switchgrass systems cannot compete economically with high-input (managed) switchgrass systems. Finally, in the third chapter, I evaluate the economic and land quality conditions required for switchgrass to be competitive with a corn/soy rotation. I find that switchgrass can displace low-yielding corn/soy on environmentally sensitive land but, to be competitive, it requires economic support through payments for ecosystem services equal to 360 ha-1. With a total expenditure of 4.3 billion annually for ecosystem services, switchgrass could displace corn/soy on 12.2 million hectares of environmentally sensitive land and increase ethanol production above that from the existing corn by 20 billion liters. Thus, ecosystem services can be an effective means of meeting both bioenergy and environmental goals. Taking the three chapters in aggregate it is apparent

  9. Overexpression of AtLOV1 in Switchgrass Alters Plant Architecture, Lignin Content, and Flowering Time

    Science.gov (United States)

    Xu, Bin; Sathitsuksanoh, Noppadon; Tang, Yuhong; Udvardi, Michael K.; Zhang, Ji-Yi; Shen, Zhengxing; Balota, Maria; Harich, Kim; Zhang, Percival Y.-H.; Zhao, Bingyu

    2012-01-01

    Background Switchgrass (Panicum virgatum L.) is a prime candidate crop for biofuel feedstock production in the United States. As it is a self-incompatible polyploid perennial species, breeding elite and stable switchgrass cultivars with traditional breeding methods is very challenging. Translational genomics may contribute significantly to the genetic improvement of switchgrass, especially for the incorporation of elite traits that are absent in natural switchgrass populations. Methodology/Principal Findings In this study, we constitutively expressed an Arabidopsis NAC transcriptional factor gene, LONG VEGETATIVE PHASE ONE (AtLOV1), in switchgrass. Overexpression of AtLOV1 in switchgrass caused the plants to have a smaller leaf angle by changing the morphology and organization of epidermal cells in the leaf collar region. Also, overexpression of AtLOV1 altered the lignin content and the monolignol composition of cell walls, and caused delayed flowering time. Global gene-expression analysis of the transgenic plants revealed an array of responding genes with predicted functions in plant development, cell wall biosynthesis, and flowering. Conclusions/Significance To our knowledge, this is the first report of a single ectopically expressed transcription factor altering the leaf angle, cell wall composition, and flowering time of switchgrass, therefore demonstrating the potential advantage of translational genomics for the genetic improvement of this crop. PMID:23300513

  10. Overexpression of AtLOV1 in Switchgrass alters plant architecture, lignin content, and flowering time.

    Directory of Open Access Journals (Sweden)

    Bin Xu

    Full Text Available BACKGROUND: Switchgrass (Panicum virgatum L. is a prime candidate crop for biofuel feedstock production in the United States. As it is a self-incompatible polyploid perennial species, breeding elite and stable switchgrass cultivars with traditional breeding methods is very challenging. Translational genomics may contribute significantly to the genetic improvement of switchgrass, especially for the incorporation of elite traits that are absent in natural switchgrass populations. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we constitutively expressed an Arabidopsis NAC transcriptional factor gene, LONG VEGETATIVE PHASE ONE (AtLOV1, in switchgrass. Overexpression of AtLOV1 in switchgrass caused the plants to have a smaller leaf angle by changing the morphology and organization of epidermal cells in the leaf collar region. Also, overexpression of AtLOV1 altered the lignin content and the monolignol composition of cell walls, and caused delayed flowering time. Global gene-expression analysis of the transgenic plants revealed an array of responding genes with predicted functions in plant development, cell wall biosynthesis, and flowering. CONCLUSIONS/SIGNIFICANCE: To our knowledge, this is the first report of a single ectopically expressed transcription factor altering the leaf angle, cell wall composition, and flowering time of switchgrass, therefore demonstrating the potential advantage of translational genomics for the genetic improvement of this crop.

  11. Towards uncovering the roles of switchgrass peroxidases in plant processes

    Directory of Open Access Journals (Sweden)

    Aaron eSaathoff

    2013-06-01

    Full Text Available Herbaceous perennial plants selected as potential biofuel feedstocks had been understudied at the genomic and functional genomic levels. Recent investments, primarily by the U.S. Department of Energy, have led to the development of a number of molecular resources for bioenergy grasses, such as the partially annotated genome for switchgrass (Panicum virgatum L., and some related diploid species. In its current version, the switchgrass genome contains 65,878 gene models arising from the A and B genomes of this tetraploid grass. The availability of these gene sequences provides a framework to exploit transcriptomic data obtained from next generation sequencing platforms to address questions of biological importance. One such question pertains to discovery of genes and proteins important for biotic and abiotic stress responses, and how these components might affect biomass quality and stress response in plants engineered for a specific end purpose. It can be expected that production of switchgrass on marginal lands will expose plants to diverse stresses, including herbivory by insects. Class III plant peroxidases have been implicated in many developmental responses such as lignification and in the adaptive responses of plants to insect feeding. Here, we have analyzed the class III peroxidases encoded by the switchgrass genome, and have mined available transcriptomic datasets to develop a first understanding of the expression profiles of the class III peroxidases in different plant tissues. Lastly, we have identified switchgrass peroxidases that appear to be orthologs of enzymes shown to play key roles in lignification and plant defense responses to hemipterans.

  12. Switchgrass, Bermudagrass, Flaccidgrass, and Lovegrass biomass yield response to nitrogen for single and double harvest

    International Nuclear Information System (INIS)

    Aravindhakshan, Sijesh C.; Epplin, Francis M.; Taliaferro, Charles M.

    2011-01-01

    Switchgrass (Panicum virgatum) has been identified as a model dedicated energy crop species. After a perennial grass is established, the major variable costs are for nitrogen (N) fertilizer and harvest. Prior to establishing switchgrass on millions of ha in a particular agro-climatic region, it would be useful to determine switchgrass yield response to N and its response to harvest frequency relative to alternative grass species. The objective of this research is to determine biomass yield response to N for four perennial grass species and to determine the species, N level, and harvest frequency that will maximize expected net returns, given the climate and soils of the U.S.A. Southern Plains. Yield data were produced in an experiment that includes four species (switchgrass, bermudagrass (Cynodon dactylon), weeping lovegrass (Eragrostis curvula), and carostan flaccidgrass (Pennisetum flaccidum)), four N levels, and two harvest levels. Linear response plateau (LRP), linear response stochastic plateau (LRSP), and quadratic response (QR) functions are estimated. For all combinations of biomass and N prices considered, the optimal species is switchgrass. For most price situations, it is economically optimal to fertilize established stands of switchgrass with 69 kg N ha -1 yr -1 and to harvest once yr -1 after senescence. (author)

  13. Integrating future scenario‐based crop expansion and crop conditions to map switchgrass biofuel potential in eastern Nebraska, USA

    Science.gov (United States)

    Gu, Yingxin; Wylie, Bruce K.

    2018-01-01

    Switchgrass (Panicum virgatum) has been evaluated as one potential source for cellulosic biofuel feedstocks. Planting switchgrass in marginal croplands and waterway buffers can reduce soil erosion, improve water quality, and improve regional ecosystem services (i.e. it serves as a potential carbon sink). In previous studies, we mapped high risk marginal croplands and highly erodible cropland buffers that are potentially suitable for switchgrass development, which would improve ecosystem services and minimally impact food production. In this study, we advance our previous study results and integrate future crop expansion information to develop a switchgrass biofuel potential ensemble map for current and future croplands in eastern Nebraska. The switchgrass biomass productivity and carbon benefits (i.e. NEP: net ecosystem production) for the identified biofuel potential ensemble areas were quantified. The future scenario‐based (‘A1B’) land use and land cover map for 2050, the US Geological Survey crop type and Compound Topographic Index (CTI) maps, and long‐term (1981–2010) averaged annual precipitation data were used to identify future crop expansion regions that are suitable for switchgrass development. Results show that 2528 km2 of future crop expansion regions (~3.6% of the study area) are potentially suitable for switchgrass development. The total estimated biofuel potential ensemble area (including cropland buffers, marginal croplands, and future crop expansion regions) is 4232 km2 (~6% of the study area), potentially producing 3.52 million metric tons of switchgrass biomass per year. Converting biofuel ensemble regions to switchgrass leads to potential carbon sinks (the total NEP for biofuel potential areas is 0.45 million metric tons C) and is environmentally sustainable. Results from this study improve our understanding of environmental conditions and ecosystem services of current and future cropland systems in eastern Nebraska and provide

  14. Impacts of Improved Switchgrass and Big Bluestem Selections on Yield, Morphological Characteristics, and Biomass Quality

    Directory of Open Access Journals (Sweden)

    Erik Delaquis

    2014-01-01

    Full Text Available Switchgrass (Panicum virgatum L. and big bluestem (Andropogon gerardii V. are promising warm-season grasses for biomass production. Understanding the morphological and quality-related traits of these grasses can guide breeders in developing strategies to improve yield and quality for bioindustrial applications. Elite selections were made in Southern Quebec from four promising varieties of switchgrass and one of big bluestem. Biomass yield, morphological characteristics, and selected quality traits were evaluated at two sites in 2011 and 2012. Significant variation was detected for all measured characteristics, with differences varying by site and year. In some cases the selection process modified characteristics including increasing height and reducing tiller mortality. Switchgrasses reached a similar tiller equilibrium density in both years of 690 m−2 and 379 m−2 at a productive and marginal site, respectively. Differences in yield were pronounced at the marginal site, with some advanced selections having a higher yield than their parent varieties. Switchgrass yields were generally greater than those of big bluestem. A delayed spring harvest date greatly reduced yield but reduced moisture content and slightly increased cellulose concentration. Big bluestem had a higher cellulose content than switchgrass, likely due to greater stem content.

  15. A review of carbon and nitrogen balances in switchgrass grown for energy

    International Nuclear Information System (INIS)

    Bransby, D.I.; McLaughlin, S.B.; Parrish, D.J.

    1998-01-01

    Increased atmospheric CO 2 caused partly by burning fossil fuels, is assumed to elevate the risk of global warming, while nitrate contamination of surface runoff and groundwater from fertilizer and agricultural wastes constitutes a serious environmental hazard on a regional scale. Switchgrass (Panicum virgatum L.) grown as an energy crop could reduce atmospheric CO 2 accumulation by replacing fossil fuels and sequestering C. It could also improve soil productivity by C sequestration, and reduce NO 3 -1 contamination of water by absorbing N lost from fertilizer and agricultural waste if planted in filter strips on adjacent land. The objective of this study was to assess potential impacts of switchgrass on C and N balances by reviewing and synthesizing information from current literature, unpublished data and on-going research. Replacing fossil fuels with switchgrass, or any other biomass, will have a much greater effect on atmospheric CO 2 than C sequestration. This is because replacing fossil fuels provides a cumulative effect, while C sequestration offers only a one-time benefit. Furthermore, switchgrass will provide net gains in C sequestration only if it replaces annual row crops, but not if it replaces grazed pasture. Nitrogen recovery by switchgrass in an Alabama study was 65.6%, which compares favorably with the 50% recovery frequently quoted as the norm for wheat (Triticum aestivum L.) and corn (Zea mays L.). (Author)

  16. Effects of switchgrass cultivars and intraspecific differences in root structure on soil carbon inputs and accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Adkins, Jaron [Michigan State Univ., East Lansing, MI (United States); Jastrow, Julie D. [Argonne National Lab. (ANL), Argonne, IL (United States); Morris, Geoffrey P. [Kansas State Univ., Manhattan, KS (United States); Six, Johan [Swiss Federal Inst. of Technology, Zurich (Switzerland); de Graaff, Marie-Anne [Boise State Univ., ID (United States)

    2016-01-01

    Switchgrass (Panicum virgatum L), a cellulosic biofuel feedstock, may promote soil C 21 accumulation compared to annual cropping systems by increasing the amount and retention of 22 root-derived soil C inputs. The aim of this study was to assess how different switchgrass 23 cultivars impact soil C inputs and retention, whether these impacts vary with depth, and whether 24 specific root length (SRL) explains these impacts. We collected soil to a depth of 30 cm from six 25 switchgrass cultivars with root systems ranging from high to low SRL. The cultivars (C4 species) 26 were grown for 27 months on soils previously dominated by C3 plants, allowing us to use the 27 natural difference in 13C isotopic signatures between C3 soils and C4 plants to quantify 28 switchgrass-derived C accumulation. The soil was fractionated into coarse particulate organic 29 matter (CPOM), fine particulate organic matter (FPOM), silt, and clay-sized fractions. We 30 measured total C and plant-derived C in all soil fractions across all depths. The study led to two main results: (1) bulk soil C concentrations beneath switchgrass cultivars varied by 40% in the 0-32 10 cm soil depth and by 70% in the 10-20 cm soil depth, and cultivars with high bulk soil C 33 concentrations tended to have relatively high C concentrations in the mineral soil fractions and 34 relatively low C concentrations in the POM fractions; (2) there were significant differences in 35 switchgrass-derived soil C between cultivars at the 0-10 cm depth, where soil C inputs ranged 36 from 1.2 to 3.2 mg C g-1 dry soil. There was also evidence of a positive correlation between SRL 37 and switchgrass-derived C inputs when one outlier data point was removed. These results 38 indicate that switchgrass cultivars differentially impact mechanisms contributing to soil C accumulation.

  17. Research and Technology Development for Genetic Improvement of Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Kausch, Albert [Univ. of Rhode Island, Kingston, RI (United States); Rhodes, Richard [Univ. of Rhode Island, Kingston, RI (United States)

    2017-05-02

    This research adds to the understanding of switchgrass genetics and the increasing of biomass relevant to production of bioenergy. Switchgrass, Panicum virgatum L., and its related species are well known as potential bioenergy crops since the early 1990s. There are global economic, political, US national security and environmental pressures to increase renewable biofuel production and utilization to offset gasoline and diesel fuel use and climate change, especially in the liquid fuel transportation sector. To realize the potential of bioenergy crops, rapid genetic improvement of the most promising perennial grass feedstocks, such as switchgrass, are anticipated by current genomics, association genetics, marker assisted breeding, hybrid plant development, advanced tissue culture, conventional genetics and other approaches to increase yield, processability, and regional adaptation. The technical effectiveness and economic feasibility of the methods or techniques investigated are demonstrated by several publications, presentations and patents produced as an outcome and deliverable of this research. This project is of a broad benefit to the public not only through the dissemination of this information but also to the development of new methods which will be applied to future bioenergy crop improvement as well as other crops.

  18. Targeted discovery of glycoside hydrolases from a switchgrass-adapted compost community

    Energy Technology Data Exchange (ETDEWEB)

    Allgaier, M.; Reddy, A.; Park, J. I.; Ivanova, N.; D' haeseleer, P.; Lowry, S.; Sapra, R.; Hazen, T.C.; Simmons, B.A.; VanderGheynst, J. S.; Hugenholtz, P.

    2009-11-15

    Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, {approx}10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50 C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

  19. Fiber length and pulping characteristics of switchgrass, alfalfa stems, hybrid poplar and willow biomasses.

    Science.gov (United States)

    Ai, Jun; Tschirner, Ulrike

    2010-01-01

    Switchgrass (Panicum virgatum), alfalfa stems (Medicago sativa), second year growth hybrid poplar (Populus) and willow (Salix spp.) were examined to determine fiber characteristics, pulping behavior and paper properties. Alfalfa stems and switchgrass both showed length weighted average fiber length (LWW) of 0.78 mm, a very narrow fiber length distribution and high fines content. Willow and hybrid poplar have lower fines content but a very low average fiber length (0.42 and 0.48 mm LWW). In addition, the four biomass species showed distinctly different chemical compositions. Switchgrass was defibered successfully using Soda and Soda Anthraquinone (AQ) pulping and demonstrated good paper properties. Both fast-growing wood species pulped well using the Kraft process, and showed acceptable tensile strength, but low tear strength. Alfalfa stems reacted very poorly to Soda and Soda AQ pulping but responded well to Kraft and Kraft AQ. Pulps with tensile and tear strength considerably higher than those found for commercial aspen pulps were observed for alfalfa. All four biomass species examined demonstrated low pulp yield. The highest yields were obtained with poplar and switchgrass (around 43%). Considering the short fibers and low yields, all four biomass types will likely only be used in paper manufacturing if they offer considerable economic advantage over traditional pulp wood.

  20. Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Amitha; Allgaier, Martin; Park, Joshua I.; Ivanoval, Natalia; Dhaeseleer, Patrik; Lowry, Steve; Sapra, Rajat; Hazen, Terry C.; Simmons, Blake A.; VanderGheynst, Jean S.; Hugenholtz, Philip

    2011-05-11

    Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Smallsubunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, ,10percent were putative cellulasesmostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50uC and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

  1. Non-targeted Colonization by the Endomycorrhizal Fungus, Serendipita vermifera, in Three Weeds Typically Co-occurring with Switchgrass

    Directory of Open Access Journals (Sweden)

    Prasun Ray

    2018-01-01

    Full Text Available Serendipita vermifera (=Sebacina vermifera; isolate MAFF305830 is a mycorrhizal fungus originally isolated from the roots of an Australian orchid that we have previously shown to be beneficial in enhancing biomass yield and drought tolerance in switchgrass, an important bioenergy crop for cellulosic ethanol production in the United States. However, almost nothing is known about how this root-associated fungus proliferates and grows through the soil matrix. Such information is critical to evaluate the possibility of non-target effects, such as unintended spread to weedy plants growing near a colonized switchgrass plant in a field environment. A microcosm experiment was conducted to study movement of vegetative mycelia of S. vermifera between intentionally inoculated switchgrass (Panicum virgatum L. and nearby weeds. We constructed size-exclusion microcosms to test three different common weeds, large crabgrass (Digitaria sanguinalis L., Texas panicum (Panicum texanum L., and Broadleaf signalgrass (Brachiaria platyphylla L., all species that typically co-occur in Southern Oklahoma and potentially compete with switchgrass. We report that such colonization of non-target plants by S. vermifera can indeed occur, seemingly via co-mingled root systems. As a consequence of colonization, significant enhancement of growth was noted in signalgrass, while a mild increase (albeit not significant was evident in crabgrass. Migration of the fungus seems unlikely in root-free bulk soil, as we failed to see transmission when the roots were kept separate. This research is the first documentation of non-targeted colonization of this unique root symbiotic fungus and highlights the need for such assessments prior to deployment of biological organisms in the field.

  2. Non-targeted Colonization by the Endomycorrhizal Fungus, Serendipita vermifera, in Three Weeds Typically Co-occurring with Switchgrass

    Science.gov (United States)

    Ray, Prasun; Guo, Yingqing; Kolape, Jaydeep; Craven, Kelly D.

    2018-01-01

    Serendipita vermifera (=Sebacina vermifera; isolate MAFF305830) is a mycorrhizal fungus originally isolated from the roots of an Australian orchid that we have previously shown to be beneficial in enhancing biomass yield and drought tolerance in switchgrass, an important bioenergy crop for cellulosic ethanol production in the United States. However, almost nothing is known about how this root-associated fungus proliferates and grows through the soil matrix. Such information is critical to evaluate the possibility of non-target effects, such as unintended spread to weedy plants growing near a colonized switchgrass plant in a field environment. A microcosm experiment was conducted to study movement of vegetative mycelia of S. vermifera between intentionally inoculated switchgrass (Panicum virgatum L.) and nearby weeds. We constructed size-exclusion microcosms to test three different common weeds, large crabgrass (Digitaria sanguinalis L.), Texas panicum (Panicum texanum L.), and Broadleaf signalgrass (Brachiaria platyphylla L.), all species that typically co-occur in Southern Oklahoma and potentially compete with switchgrass. We report that such colonization of non-target plants by S. vermifera can indeed occur, seemingly via co-mingled root systems. As a consequence of colonization, significant enhancement of growth was noted in signalgrass, while a mild increase (albeit not significant) was evident in crabgrass. Migration of the fungus seems unlikely in root-free bulk soil, as we failed to see transmission when the roots were kept separate. This research is the first documentation of non-targeted colonization of this unique root symbiotic fungus and highlights the need for such assessments prior to deployment of biological organisms in the field. PMID:29375607

  3. Bio-remediation of Pb and Cd polluted soils by switchgrass: A case study in India.

    Science.gov (United States)

    Arora, Kalpana; Sharma, Satyawati; Monti, Andrea

    2016-01-01

    In the present study bioremediation potential of a high biomass yielding grass, Panicum virgatum (switchgrass), along with plant associated microbes (AM fungi and Azospirillum), was tested against lead and cadmium in pot trials. A pot trial was set up in order to evaluate bioremediation efficiency of P. virgatum in association with PAMs (Plant Associated Microbes). Growth parameters and bioremediation potential of endomycorrhizal fungi (AMF) and Azospirillum against different concentrations of Pb and Cd were compared. AM fungi and Azospirillum increased the root length, branches, surface area, and root and shoot biomass. The soil pH was found towards neutral with AMF and Azospirillum inoculations. The bioconcentration factor (BCF) for Pb (12 mg kg(-1)) and Cd (10 mg kg(-1)) were found to be 0.25 and 0.23 respectively and translocation index (Ti) was 17.8 and 16.7 respectively (approx 45% higher than control). The lower values of BCF and Ti, even at highest concentration of Pb and Cd, revealed the capability of switchgrass of accumulating high concentration of Pb and Cd in the roots, while preventing the translocation of Pb and Cd to aerial biomass.

  4. ASSESSING OF HERBIVOROUS AND BENEFICIAL INSECTS ON SWITCHGRASS IN UKRAINE.

    Science.gov (United States)

    Stefanovska, T; Kucherovska, S; Pisdlisnyuk, V

    2014-01-01

    A perennial switchgrass, (Panicum virgatum L.), (C4) that is native to North America has good potential for biomass production because of its wide geographic distribution and adaptability to diverse environmental conditions. Insects can significantly impact the yield and quality of biofuel crops. If switchgrass are to be grown on marginally arable land or in monoculture, it are likely to be plagued with herbivore pests and plant diseases at a rate that exceeds what would be expected if the plants were not stressed in this manner. This biofuel crop has been under evaluation for commercial growing in Ukraine for eight years. However, insect diversity and the potential impact of pests on biomass production of this feedstock have not been accessed yet. The objective of our study, started in 2011, is a survey of switch grass insects by trophic groups and determine species that have pest status at two sites in the Central part of Ukraine (Kiev and Poltava regions). In Poltava site we investigated the effect of nine varieties of switchgrass (lowland and upland) to insects' diversity. We assessed changes over time in the densities of major insects' trophic groups, identifying potential pests and natural enemies. Obtained results indicates that different life stages of herbivorous insects from Hymenoptera, Homoptera, Diptera and Coleoptera orders were present on switchgrass during the growing season. Our study results suggests that choice of variety has an impact on trophic groups' structure and number of insects from different orders on swicthgrass. Herbivores and beneficial insects were the only groups that showed significant differences across sampling dates. The highest population of herbivores insects we recorded on 'Alamo' variety for studied years, although herbivore diversity tended to increase on 'Shelter', 'Alamo' and 'Cave-in-Rock' during 2012 and 2013. 'Dacotah', 'Nebraska', 'Sunburst', 'Forestburg' and 'Carthage' showed the highest level of beneficial insects

  5. Economic assessment of short-rotation forestry and switchgrass plantations for energy production in central Canada

    International Nuclear Information System (INIS)

    Girouard, P.; Samson, R.; Henning, J. C.

    1996-01-01

    A joint research program between Resource Efficient Agricultural Production (REAP)-Canada and McGill University to determine which factors are limiting biomass productivity and cost-effectiveness for various biomass crops was described, focusing on the two main crops investigated, namely willow trees (Salix spp>) and switchgrass (Panicum virgatum), a perennial grass. Estimates of the cost of growing both crops in Central Canada, based on quasi-commercial size plots, were given. The advantages and disadvantages of each crop as an energy source were discussed. It was suggested that in addition to the energy sector, other markets, such as papermaking, should be investigated to achieve the full potential of these new crops. 6 refs., 2 tabs., 5 figs

  6. Inside out: high-efficiency plant regeneration and Agrobacterium-mediated transformation of upland and lowland switchgrass cultivars.

    Science.gov (United States)

    Liu, Yan-Rong; Cen, Hui-Fang; Yan, Jian-Ping; Zhang, Yun-Wei; Zhang, Wan-Jun

    2015-07-01

    Selection of pre-embryogenic callus from a core structure from mature seed-derived callus is the key for high-efficiency plant regeneration and transformation of switchgrass different cultivars. Switchgrass (Panicum virgatum L.) has been identified as a dedicated biofuel crop. For its trait improvement through biotechnological approaches, we have developed a highly efficient plant regeneration and genetic transformation protocol for both lowland and upland cultivars. We identified and separated a pre-embryogenic "core" structure from the seed-derived callus, which often leads to development of highly regenerative type II calluses. From the type II callus, plant regeneration rate of lowland cultivars Alamo and Performer reaches 95%, and upland cultivars Blackwell and Dacotah, 50 and 76%, respectively. The type II callus was also amenable for Agrobacterium-mediated transformation. Transformation efficiency of 72.8% was achieved for lowland cultivar Alamo, and 8.0% for upland cultivar Dacotah. PCR, Southern blot and GUS staining assays were performed to verify the transgenic events. High regenerative callus lines could be established in 3 months, and transgenic plants could be obtained in 2 months after Agrobacterium infection. To our knowledge, this is the first report on successful plant regeneration and recovery of transgenic plants from upland switchgrass cultivars by Agrobacterium-mediated transformation. The method presented here could be helpful in breaking through the bottleneck of regeneration and transformation of lowland and upland switchgrass cultivars and probably other recalcitrant grass crops.

  7. Volatile organic compound emissions from switchgrass cultivars used as biofuel crops

    Science.gov (United States)

    Eller, A. S. D.; Sekimoto, K.; Gilman, J. B.; Kuster, W. C.; de Gouw, J. A.; Monson, R. K.; Graus, M.; Crespo, E.; Warneke, C.; Fall, R.

    2011-06-01

    Volatile organic compound (VOC) emission rates during the growth and simulated harvest phases were determined for switchgrass (Panicum virgatum) using laboratory chamber measurements. Switchgrass is a candidate for use in second-generation (cellulosic) biofuel production and the acreage dedicated to its growth in the USA has already increased during the past decade. We estimate that the yearly emissions from switchgrass plantations, including both the growth and harvest phases will be on the order of 3 kg C ha-1 methanol, 1 kg C ha-1 acetaldehyde, 1 kg C ha-1 acetone, 0.9 kg C ha-1 monoterpenes, 0.5 kg C ha-1 isoprene + another compound, most likely 1-penten-3-ol, 0.2 kg C ha-1 hexenals, and 0.1 kg C ha-1 hexenols. These emission rates are much lower than those expected from Eucalyptus or poplar plantations, which are other potential biofuel crops and have significantly higher VOC emissions, suggesting that the choice of species in the production of biofuels could have serious implications for regional air quality.

  8. Switchgrass Cultivar/Ecotype Selection and Management for Biofuels in the Upper Southeast USA

    Science.gov (United States)

    Parrish, David J.; Wolf, Dale D.

    2014-01-01

    Switchgrass (Panicum virgatum L.), a perennial warm-season grass indigenous to the eastern USA, has potential as a biofuels feedstock. The objective of this study was to investigate the performance of upland and lowland switchgrass cultivars under different environments and management treatments. Four cultivars of switchgrass were evaluated from 2000 to 2001 under two management regimes in plots established in 1992 at eight locations in the upper southeastern USA. Two management treatments included 1) a single annual harvest (in late October to early November) and a single application of 50 kg N/ha/yr and 2) two annual harvests (in midsummer and November) and a split application of 100 kg N/ha/yr. Biomass yields averaged 15 Mg/ha/yr and ranged from 10 to 22 Mg/ha/yr across cultivars, managements, locations, and years. There was no yield advantage in taking two harvests of the lowland cultivars (Alamo and Kanlow). When harvested twice, upland cultivars (Cave-in-Rock and Shelter) provided yields equivalent to the lowland ecotypes. Tiller density was 36% lower in stands cutting only once per year, but the stands appeared vigorous after nine years of such management. Lowland cultivars and a one-cutting management (after the tops have senesced) using low rates of applied N (50 kg/ha) are recommended. PMID:25105170

  9. Electron beam pretreatment of switchgrass to enhance enzymatic hydrolysis to produce sugars for biofuels.

    Science.gov (United States)

    Sundar, Smith; Bergey, N Scott; Salamanca-Cardona, Lucia; Stipanovic, Arthur; Driscoll, Mark

    2014-01-16

    Conversion of lignocellulosic biomass to value added products such as ethanol and other platform chemicals is enhanced by pretreatment, which reduces the crystallinity and molecular weight of cell wall polymers, thus increasing the available reaction sites. In this study, switchgrass (Panicum virgatum L.) was pretreated with high energy electron beam (EB) irradiation to reduce its recalcitrance and achieve higher sugar conversion rates during treatment with cellulases and β-glucosidase. Conversion rates to sugars were compared before and after hot water (HW) extraction of EB-treated and control samples of switchgrass. Thermogravimetric analysis (TGA) was employed to determine peak degradation temperature of these EB-treated biomass samples before and after HW extraction, and near infrared spectroscopy (NIR) was used as a rapid technique to determine cellulose, hemicellulose, and lignin contents in the samples. TGA data confirm previously reported results that EB pretreatment reduces the molecular weight and crystallinity of cellulose and hemicellulose. This leaves hemicellulose more amenable to HW extraction and creates more cellulase-accessible sites, as shown by NIR and glucose yield data, respectively. Hemicellulose content was reduced from 30.2 to 16.9% after HW extraction and 1000 kGy EB treatment, and ultimate glucose yield after cellulase hydrolysis increased more than 4-fold. This study provides evidence that when EB pretreatment is utilized in combination with HW extraction, higher conversion rates and yields of glucose can be obtained from the cellulosic fraction of switchgrass. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Microbial community analysis of switchgrass planted and unplanted soil microcosms displaying PCB dechlorination.

    Science.gov (United States)

    Liang, Yi; Meggo, Richard; Hu, Dingfei; Schnoor, Jerald L; Mattes, Timothy E

    2015-08-01

    Polychlorinated biphenyls (PCBs) pose potential risks to human and environmental health because they are carcinogenic, persistent, and bioaccumulative. In this study, we investigated bacterial communities in soil microcosms spiked with PCB 52, 77, and 153. Switchgrass (Panicum virgatum) was employed to improve overall PCB removal, and redox cycling (i.e., sequential periods of flooding followed by periods of no flooding) was performed in an effort to promote PCB dechlorination. Lesser chlorinated PCB transformation products were detected in all microcosms, indicating the occurrence of PCB dechlorination. Terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis showed that PCB spiking, switchgrass planting, and redox cycling affected the microbial community structure. Putative organohalide-respiring Chloroflexi populations, which were not found in unflooded microcosms, were enriched after 2 weeks of flooding in the redox-cycled microcosms. Sequences classified as Geobacter sp. were detected in all microcosms and were most abundant in the switchgrass-planted microcosm spiked with PCB congeners. The presence of possible organohalide-respiring bacteria in these soil microcosms suggests that they play a role in PCB dechlorination therein.

  11. Accumulation and partitioning of biomass, nutrients, and trace elements in switchgrass for phytoremediation of municipal biosolids.

    Science.gov (United States)

    Jeke, Nicholson N; Zvomuya, Francis; Ross, Lisette

    2016-09-01

    In situ phytoremediation of municipal biosolids is a promising alternative to the land spreading and landfilling of biosolids from end-of-life municipal lagoons. Accumulation and partitioning of dry matter, nitrogen (N), phosphorus (P), and trace elements were determined in aboveground biomass (AGB) and belowground biomass (BGB) of switchgrass (Panicum virgatum L.) to determine the harvest stage that maximizes phytoextraction of contaminants from municipal biosolids. Seedlings were transplanted into 15-L plastic pails containing 3.9 kg (dry wt.) biosolids. Biomass yield components and contaminant concentrations were assessed every 14 days for up to 161 days. Logistic model fits to biomass yield data indicated no significant differences in asymptotic yield between AGB and BGB. Switchgrass partitioned significantly more N and P to AGB than to BGB. Maximum uptake occurred 86 days after transplanting (DAT) for N and 102 DAT for P. Harvesting at peak aboveground element accumulation removed 5% of N, 1.6% of P, 0.2% of Zn, 0.05% of Cd, and 0.1% of Cr initially present in the biosolids. These results will contribute toward identification of the harvest stage that will optimize contaminant uptake and enhance in situ phytoremediation of biosolids using switchgrass.

  12. Comparison of the Carbon Budget, Evapotranspiration, and Albedo Effect between the Biofuel Crops Switchgrass and Corn

    Science.gov (United States)

    Eichelmann, E.; Wagner-Riddle, C.; Warland, J. S.; Deen, B.; Voroney, P.

    2015-12-01

    Switching from annual cropping systems to perennial crops like switchgrass (Panicum virgatum L.) for biofuel feedstock production will have implications on carbon and water cycling as well as biophysical parameters, such as surface albedo.We conducted eddy covariance measurements of carbon dioxide and water fluxes over a mature (>5 years) switchgrass field over three years (2012 to 2014) and a continuous corn field during the year 2014. Both fields were located in Southern Ontario, Canada. Results for carbon and water cycling were compared between the two crops for the year 2014. Differences in surface albedo between the two biofuel cropping systems were compared for the years 2012, 2013, and 2014. In 2014 switchgrass was a carbon sink with a net ecosystem carbon balance (NECB) of -66±59 g C m-2, while corn was a carbon source with an NECB of 328±30 g C m-2 for a scenario where corn grain only is harvested and 634±34 g C m-2 for a scenario where both grain and stover are harvested. Annual evapotranspiration in 2014 was higher for the corn field (608.7±12 mm) than for the switchgrass field (517.0±8 mm). Albedo measurements showed an average annual negative radiative forcing effect for the switchgrass field compared to corn. Differences in albedo were largest in spring and fall when radiative forcing values of -10.2 and -5.5 W m-2 were observed, respectively.Comparing carbon cycling results from previous years, the switchgrass field was a source of carbon in 2012 (NEBC 106±45 g C m-2), but a small sink of carbon in 2013 (NEBC -59±45) and 2014. On average over the three measurement years, the switchgrass field was carbon neutral.Qualitative analysis of the carbon budget, evapotranspiration, and albedo results from this study suggest that biofuel produced from switchgrass can have more climate benefits than biofuel from continuous corn. This study provides important data for improvement of Life Cycle Analysis of switchgrass biofuel.

  13. Economics of switchgrass and miscanthus relative to coal as feedstock for generating electricity

    International Nuclear Information System (INIS)

    Aravindhakshan, Sijesh C.; Epplin, Francis M.; Taliaferro, Charles M.

    2010-01-01

    Switchgrass (Panicum virgatum) serves as a model dedicated energy crop in the U.S.A. Miscanthus (Miscanthus x giganteus) has served a similar role in Europe. This study was conducted to determine the most economical species, harvest frequency, and carbon tax required for either of the two candidate feedstocks to be an economically viable alternative for cofiring with coal for electricity generation. Biomass yield and energy content data were obtained from a field experiment conducted near Stillwater, Oklahoma, U.S.A., in which both grasses were established in 2002. Plots were split to enable two harvest treatments (once and twice yr -1 ). The switchgrass variety 'Alamo', with a single annual post-senescence harvest, produced more biomass (15.87 Mg ha -1 yr -1 ) than miscanthus (12.39 Mg ha -1 yr -1 ) and more energy (249.6 million kJ ha -1 yr -1 versus 199.7 million kJ ha -1 yr -1 for miscanthus). For the average yields obtained, the estimated cost to produce and deliver biomass an average distance of 50 km was $43.9 Mg -1 for switchgrass and $51.7 Mg -1 for miscanthus. Given a delivered coal price of $39.76 Mg -1 and average energy content, a carbon tax of $7 Mg -1 CO 2 would be required for switchgrass to be economically competitive. For the location and the environmental conditions that prevailed during the experiment, switchgrass with one harvest per year produced greater yields at a lower cost than miscanthus. In the absence of government intervention such as requiring biomass use or instituting a carbon tax, biomass is not an economically competitive feedstock for electricity generation in the region studied. (author)

  14. Bioclimatic predictions of habitat suitability for the biofuel switchgrass in North America under current and future climate scenarios

    International Nuclear Information System (INIS)

    Barney, Jacob N.; DiTomaso, Joseph M.

    2010-01-01

    Dedicated biofuel crops, while providing economic and other benefits, may adversely impact biodiversity directly via land use conversion, or indirectly via creation of novel invasive species. To mitigate negative impacts bioclimatic envelope models (BEM) can be used to estimate the potential distribution and suitable habitat based on the climate and distribution in the native range. We used CLIMEX to evaluate the regions of North America suitable for agronomic production, as well as regions potentially susceptible to an invasion of switchgrass (Panicum virgatum) under both current and future climate scenarios. Model results show that >8.7 million km 2 of North America has suitable to very favorable habitat, most of which occurs east of the Rocky Mountains. The non-native range of western North America is largely unsuitable to switchgrass as a crop or potential weed unless irrigation or permanent water is available. Under both the CGCM2 and HadCM3 climate models and A2 and B2 emissions scenarios, an overall increase in suitable habitat is predicted over the coming century, although the western US remains unsuitable. Our results suggest that much of North America is suitable for switchgrass cultivation, although this is likely to shift north in the coming century. Our results also agree with field collections of switchgrass outside its native range, which indicate that switchgrass is unlikely to establish unless it has access to water throughout the year (e.g., along a stream). Thus, it is the potential invasion of switchgrass into riparian habitats in the West that requires further investigation. (author)

  15. Complete nucleotide sequences and virion particle association of two satellite RNAs of panicum mosaic virus.

    Science.gov (United States)

    Pyle, Jesse D; Monis, Judit; Scholthof, Karen-Beth

    2017-08-15

    Over six decades ago, panicum mosaic virus (PMV) was identified as the first viral pathogen of cultivated switchgrass (Panicum virgatum). Subsequently, PMV was demonstrated to support the replication of both a satellite RNA virus (SPMV) and satellite RNA (satRNA) agents during natural infections of host grasses. In this study, we report the isolation and full-length sequences of two PMV satRNAs identified in 1988 from St. Augustinegrass (Stenotaphrum secundatum) and centipedegrass (Eremochloa ophiuroides) hosts. Each of these satellites have sequence relatedness at their 5'- and 3'-ends. In addition, satC has a region of ∼100 nt complementary to the 3'-end of the PMV genome. These agents are associated with purified virions of SPMV infections. Additionally, satS and satC RNAs contain conserved in-frame open reading frames in the complementary-sense sequences that could potentially generate 6.6- and 7.9-kDa proteins, respectively. In protoplasts and plants satS is infectious, when co-inoculated with the PMV RNA alone or PMV+SPMV RNAs, and negatively affects their accumulation. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Switchgrass as a biofuels crop for the upper Southeast

    Energy Technology Data Exchange (ETDEWEB)

    Parrish, D.J.; Wolf, D.D. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)

    1993-12-31

    Switchgrass (Panicum virgatum) has been identified in DOE-sponsored studies as a widely adapted, productive herbaceous candidate for biofuels cropping. It is a perennial that has been planted using no-till procedures, and it appears to have positive effects on the soils in which it grows. We have been looking at this species as a potential fuelcrop (as well as a valuable forage) for several years. In this presentation, we note several {open_quotes}lessons learned{close_quotes} about switchgrass establishment and management as an energy crop. Data include results from recent plantings in the upper Southeast USA and from cutting management studies. Six varieties of switchgrass (Alamo, Cave-in-Rock, Kanlow, Shelter, and two breeder`s lines) varied markedly in the success of their no-till establishment at eight locations across the upper Southeast. Better weed control, which was achieved at later planting dates, seemed to be the key. Yields obtained in the establishment stands revealed that two harvests per season are more productive (by 2 to 3 Mg/ha) than one, but the date of first cutting is crucial. First cutting should be from late-June to mid-July. A two-cut system may not be economically advantageous, however. Another cutting-management study detected losses of standing biomass at the end of the growing season. As much as 15% of the above-ground biomass present in early-September was no longer harvestable in early-November. We think this loss results from translocation of dry matter to below-ground parts.

  17. Drought-Induced Leaf Proteome Changes in Switchgrass Seedlings

    Directory of Open Access Journals (Sweden)

    Zhujia Ye

    2016-08-01

    Full Text Available Switchgrass (Panicum virgatum is a perennial crop producing deep roots and thus highly tolerant to soil water deficit conditions. However, seedling establishment in the field is very susceptible to prolonged and periodic drought stress. In this study, a “sandwich” system simulating a gradual water deletion process was developed. Switchgrass seedlings were subjected to a 20-day gradual drought treatment process when soil water tension was increased to 0.05 MPa (moderate drought stress and leaf physiological properties had expressed significant alteration. Drought-induced changes in leaf proteomes were identified using the isobaric tags for relative and absolute quantitation (iTRAQ labeling method followed by nano-scale liquid chromatography mass spectrometry (nano-LC-MS/MS analysis. Additionally, total leaf proteins were processed using a combinatorial library of peptide ligands to enrich for lower abundance proteins. Both total proteins and those enriched samples were analyzed to increase the coverage of the quantitative proteomics analysis. A total of 7006 leaf proteins were identified, and 257 (4% of the leaf proteome expressed a significant difference (p < 0.05, fold change <0.6 or >1.7 from the non-treated control to drought-treated conditions. These proteins are involved in the regulation of transcription and translation, cell division, cell wall modification, phyto-hormone metabolism and signaling transduction pathways, and metabolic pathways of carbohydrates, amino acids, and fatty acids. A scheme of abscisic acid (ABA-biosynthesis and ABA responsive signal transduction pathway was reconstructed using these drought-induced significant proteins, showing systemic regulation at protein level to deploy the respective mechanism. Results from this study, in addition to revealing molecular responses to drought stress, provide a large number of proteins (candidate genes that can be employed to improve switchgrass seedling growth and

  18. Simulated biomass, environmental impacts and best management practices for long-term switchgrass systems in a semi-arid region

    International Nuclear Information System (INIS)

    Wang, Limei; Qian, Yaling; Brummer, Joe E.; Zheng, Jiyong; Wilhelm, Sarah; Parton, William J.

    2015-01-01

    Long-term information on switchgrass (Panicum virgatum L.) as a biomass energy crop grown on marginally saline soil and the associated impacts on soil carbon (C) and nitrogen (N) dynamics, greenhouse gas (GHG) emissions, and best management practices (BMPs) are limited. In this study, we employed the DAYCENT model, based on a 4-year switchgrass field experiment, to evaluate the long-term biomass yield potential and environmental impacts, and further to develop BMPs for switchgrass in a semi-arid region. The model showed that long-term (14-year) annual mean biomass yields were 9.6 and 5.2 Mg ha −1 for irrigated and rainfed switchgrass systems, respectively. The simulated biomass yields correlated well with field-measured biomass with r 2 values of 0.99 and 0.89 for irrigated and rainfed systems, respectively. Soil organic carbon (SOC) and soil total nitrogen (STN) accumulated rapidly after switchgrass establishment, with mean accrual rates of 0.99–1.13 Mg C ha −1  yr −1 and 0.04–0.08 Mg N ha −1  yr −1 , respectively. Based on the outputs of numerous long-term model simulations with variable irrigation water supplies and N rates, the irrigation regime and N rate with the highest yield to input ratio were chosen as BMPs. The DAYCENT model predicted-BMP was irrigating every 14 days at 70% potential evapotranspiration combined with an N rate of 67 kg ha −1  yr −1 . Switchgrass established and produced biomass reasonably well in this semi-arid region; however, appropriate irrigation and N fertilization were needed for optimal biomass yield. Switchgrass had a great potential to sequester C into soils with low N 2 O emissions while supplying significant quantities of biomass for biofuel synthesis. - Highlights: • The DAYCENT model reliably simulated the growth of switchgrass on marginal land. • Long-term biomass and environmental impacts were simulated using the DAYCENT model. • Switchgrass produced biomass well on marginal land, but

  19. Identifying Differences in Abiotic Stress Gene Networks between Lowland and Upland Ecotypes of Switchgrass (DE-SC0008338)

    Energy Technology Data Exchange (ETDEWEB)

    Childs, Kevin [Michigan State Univ., East Lansing, MI (United States); Buell, Robin [Michigan State Univ., East Lansing, MI (United States); Zhao, Bingyu [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Zhang, Xunzhong [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2016-11-10

    Switchgrass (Panicum virgatum) is a warm-season C4 grass that is a target lignocellulosic biofuel species for use in the United States due to its local adaption capabilities and high biomass accumulation. Two ecotypes of switchgrass have been described. Members of the lowland ecotype are taller, have narrower leaf blades and generate more biomass compared to individuals from the upland ecotype. Additionally, lowland plants are generally found in the southern United States while upland switchgrass is more typically present in the northern United States. These differences are important as it is envisioned that switchgrass for biofuel production will typically be grown on marginal lands in the northern United States to supplement and diversify farmers' traditional crop incomes. While lowland switchgrass is more productive, it has poor winter survivability in northern latitudes where upland switchgrass is expected to be grown for biofuel use. Abiotic stresses likely to be encountered by switchgrass include drought and salinity. Despite initially being described as preferring wetter environments, members of the lowland ecotype have been characterized as being more drought tolerant than plants of the upland ecotype. Nonetheless, direct trials have indicated that variation for drought tolerance exists in both ecotypes, but prior to this project, only a relatively small number of switchgrass lines had been tested for drought responses. Similarly, switchgrass cultivars have not been widely tested for salt tolerance, but a few studies have shown that even mild salt stress can inhibit growth. The effects of drought and salt stress on plant growth are complex. Both drought and salinity affect the osmotic potential of plant cells and negatively affect plant growth due to reduced water potential and reduced photosynthesis that results from lower stomatal conductance of CO2. Plants respond to drought and salt stress by activating genes that directly attempt to

  20. Soil respiration, microbial biomass and exoenzyme activity in switchgrass stands under nitrogen fertilization management and climate warming.

    Science.gov (United States)

    Jian, S.; Li, J.; de Koff, J.; Celada, S.; Mayes, M. A.; Wang, G.; Guo, C.

    2016-12-01

    Switchgrass (Panicum virgatum L.), as a model bioenergy crop, received nitrogen fertilizers for increasing its biomass yields. Studies rarely investigate the interactive effects of nitrogen fertilization and climate warming on soil microbial activity and carbon cycling in switchgrass cropping systems. Enhanced nitrogen availability under fertilization can alter rates of soil organic matter decomposition and soil carbon emissions to the atmosphere and thus have an effect on climate change. Here, we assess soil CO2 emission, microbial biomass and exoenzyme activities in two switchgrass stands with no fertilizer and 60 lbs N / acre. Soils were incubated at 15 ºC and 20 ºC for 180-day. Dry switchgrass plant materials were added to incubation jars and the 13C stable isotopic probing technique was used to monitor soil CO2 respiration derived from relatively labile litter and indigenous soil. Measurements of respiration, δ13C of respiration, microbial biomass carbon and exoenzyme activity were performed on days 1, 5, 10, 15, 30, 60, 90, 120, 150 and 180. Soil respiration rate was greater in the samples incubated at 20 ºC as compared to those incubated at 15 ºC. Exoenzyme activities were significantly altered by warming, litter addition and nitrogen fertilization. There was a significant interactive effect of nitrogen fertilization and warming on the proportion of CO2 respired from soils such that nitrogen fertilization enhanced warming-induced increase by 12.0% (Pmineralization. Fertilization increased soil microbial biomass carbon at both temperatures (9.0% at 15 ºC and 14.5% at 20 ºC). Our preliminary analysis suggested that warming effects on enhanced soil respiration can be further increased with elevated fertilizer input via greater microbial biomass and exoenzyme activity. In addition to greater biomass yield under N fertilization, this study informs potential soil carbon loss from stimulated soil respiration under nitrogen fertilization and warming in

  1. Switchgrass SBP-box transcription factors PvSPL1 and 2 function redundantly to initiate side tillers and affect biomass yield of energy crop.

    Science.gov (United States)

    Wu, Zhenying; Cao, Yingping; Yang, Ruijuan; Qi, Tianxiong; Hang, Yuqing; Lin, Hao; Zhou, Gongke; Wang, Zeng-Yu; Fu, Chunxiang

    2016-01-01

    Switchgrass (Panicum virgatum L.) is a dedicated lignocellulosic feedstock for bioenergy production. The SQUAMOSA PROMOTER-BINDING PROTEIN (SBP-box)-LIKE transcription factors (SPLs) change plant architecture and vegetative-to-reproductive phase transition significantly, and as such, they are promising candidates for genetic improvement of switchgrass biomass yield. However, the genome-wide identification and functional characterization of SPL genes have yet to be investigated in herbaceous energy crops. We identified 35 full-length SPL genes in the switchgrass genome. The phylogenetic relationship and expression pattern of PvSPLs provided baseline information for their function characterization. Based on the global overview of PvSPLs, we explored the biological function of miR156-targeted PvSPL1 and PvSPL2, which are closely related members of SPL family in switchgrass. Our results showed that PvSPL1 and PvSPL2 acted redundantly to modulate side tiller initiation, whereas they did not affect phase transition and internode initiation. Consistently, overexpression of the miR156-resistant rPvSPL2 in the miR156-overexpressing transgenic plants greatly reduced tiller initiation, but did not rescue the delayed flowering and increased internode numbers. Furthermore, suppression of PvSPL2 activity in switchgrass increased biomass yield and reduced lignin accumulation, which thereby elevated the total amount of solubilized sugars. Our results indicate that different miR156-targeted PvSPL subfamily genes function predominantly in certain biological processes in switchgrass. We suggest that PvSPL2 and its paralogs can be utilized as the valuable targets in molecular breeding of energy crops for developing novel germplasms with high biofuel production.

  2. Biomass production by fescue and switchgrass alone and in mixed swards with legumes. Final project report

    Energy Technology Data Exchange (ETDEWEB)

    Collins, M. [Univ. of Kentucky, Lexington, KY (United States). Univ. of Agronomy

    1994-06-01

    In assessing the role of biomass in alleviating potential global warming, the absence of information on the sustainability of biomass production on soils of limited agricultural potential is cited as a major constraint to the assessment of the role of biomass. Research on the sustainability of yields, recycling of nutrients, and emphasis on reduced inputs of agricultural chemicals in the production of biomass are among the critical research needs to clarify optimum cropping practice in biomass production. Two field experiments were conducted between 1989 and 1993. One study evaluated biomass production and composition of switchgrass (Panicum virgatum L.) grown alone and with bigflower vetch (Vicia grandiflora L.) and the other assessed biomass productivity and composition of tall fescue (Festuca arundinacea Schreb.) grown alone and with perennial legumes. Switchgrass received 0, 75 or 150 kg ha{sup {minus}1} of N annually as NH{sub 4}NO{sub 3} or was interseeded with vetch. Tall fescue received 0, 75, 150 or 225 kg ha{sup {minus}1} of N annually or was interseeded with alfalfa (Medicago L.) or birdsfoot trefoil (Lotus corniculatus L.). It is hoped that production systems can be designed to produce high yields of biomass with minimal inputs of fertilizer N. Achievement of this goal would reduce the potential for movement of NO{sub 3} and other undesirable N forms outside the biomass production system into the environment. In addition, management systems involving legumes could reduce the cost of biomass production.

  3. Reversal of dormancy in switchgrass with low-light photoperiod extension.

    Science.gov (United States)

    Van Esbroeck, G A; Hussey, M A; Sanderson, M A

    2004-01-01

    Some switchgrass (Panicum virgatum L.) cultivars originating in the northern USA show limited late-summer and fall growth when grown in more southerly locations despite adequate temperature and moisture. Our objective was to determine the effects of low-light photoperiod extension on the dry matter yield of switchgrass cultivars originating from contrasting latitudes. Seedlings of the four cultivars (Cave-in-Rock, 'Caddo', 'Kanlow', and 'Alamo') were grown for 100 d in a greenhouse in winter under ambient (11.2-12.2 h) and extended (18 h) photoperiods. Photoperiod extension was with 7 micromol m(-2) s(-1) photosynthetic photon flux density. Cultivars responded differently to photoperiod extension (Pphotoperiods were observed in Cave-in-Rock (+98%) and Caddo (+129%). The dry matter yield of Kanlow increased by 31%, whereas dry matter yield of the southernmost cultivar Alamo was not affected by photoperiod extension. Yield increases for Cave-in-Rock and Caddo were associated with increased tiller number and weight. A reversal of dormancy for some cultivars with a photoperiodic signal verified that dormancy was not simply a result of a low radiant input.

  4. Induced Phytoextraction of Lead Through Chemical Manipulation of Switchgrass and Corn; Role of Iron Supplement.

    Science.gov (United States)

    Johnson, Deayne M; Deocampo, Daniel M; El-Mayas, Hanan; Greipsson, Sigurdur

    2015-01-01

    The effects of combined chemical application of benomyl, ethylenedianinetetraacetate (EDTA), and iron (Fe) (foliar and root) on lead (Pb) phytoextraction by switchgrass (Panicum virgatum) and corn (Zea mays) was examined. Switchgrass was grown in Pb-contaminated urban topsoil with the following treatments: (C) Control, (B) benomyl, (E) EDTA, (F) foliar-Fe, (BE) benomyl + EDTA, (BF) benomyl + foliar-Fe, (FE) foliar-Fe + EDTA, (BFE) benomyl + foliar-Fe + EDTA. Corn was grown in sand-culture supplemented with Pb (500 mg kg(-1)) with the following treatments: (C) control, (B) benomyl, (E) EDTA, (F) root-Fe, (BE) benomyl + EDTA, (BF) benomyl + root-Fe, (FE) root-iron + EDTA, and, (BFE) benomyl + root-Fe + EDTA. All treatments were replicated three times and pots were arranged in a completely randomized design. Plants were analyzed for element concentration (Fe, Zn, P, and Pb) using either inductively coupled plasma (argon) atomic emission spectroscopy (ICP-AES) or graphite furnace atomic absorption spectrometer. Iron supplementation (foliar and root) affected Pb-translocation in plants. Foliar-Fe treatment increased translocation ratio of Pb (TF-Pb) significantly compared to other treatments with the exception of plants treated with benomyl and BF. Root-Fe treatment in combination with EDTA (FE) increased TF-Pb significantly compared to other treatments. Phytoextraction was improved by the combined chemical application; plants treated with BFE treatment increased Pb-total-phytoextraction by 424% compared to Control plants.

  5. Factors affecting polyhydroxybutyrate accumulation in mesophyll cells of sugarcane and switchgrass

    Science.gov (United States)

    2014-01-01

    Background Polyhydroxyalkanoates are linear biodegradable polyesters produced by bacteria as a carbon store and used to produce a range of bioplastics. Widespread polyhydroxyalkanoate production in C4 crops would decrease petroleum dependency by producing a renewable supply of biodegradable plastics along with residual biomass that could be converted into biofuels or energy. Increasing yields to commercial levels in biomass crops however remains a challenge. Previously, lower accumulation levels of the short side chain polyhydroxyalkanoate, polyhydroxybutyrate (PHB), were observed in the chloroplasts of mesophyll (M) cells compared to bundle sheath (BS) cells in transgenic maize (Zea mays), sugarcane (Saccharum sp.), and switchgrass (Panicum virgatum L.) leading to a significant decrease in the theoretical yield potential. Here we explore various factors which might affect polymer accumulation in mesophyll cells, including targeting of the PHB pathway enzymes to the mesophyll plastid and their access to substrate. Results The small subunit of Rubisco from pea effectively targeted the PHB biosynthesis enzymes to both M and BS chloroplasts of sugarcane and switchgrass. PHB enzyme activity was retained following targeting to M plastids and was equivalent to that found in the BS plastids. Leaf total fatty acid content was not affected by PHB production. However, when fatty acid synthesis was chemically inhibited, polymer accumulated in M cells. Conclusions In this study, we provide evidence that access to substrate and neither poor targeting nor insufficient activity of the PHB biosynthetic enzymes may be the limiting factor for polymer production in mesophyll chloroplasts of C4 plants. PMID:25209261

  6. The PIN1 family gene PvPIN1 is involved in auxin-dependent root emergence and tillering in switchgrass

    Directory of Open Access Journals (Sweden)

    Kaijie Xu

    2016-03-01

    Full Text Available Abstract Switchgrass (Panicum virgatum L.; family Poaceae is a warm-season C4 perennial grass. Tillering plays an important role in determining the morphology of aboveground parts and the final biomass yield of switchgrass. Auxin distribution in plants can affect a variety of important growth and developmental processes, including the regulation of shoot and root branching, plant resistance and biological yield. Auxin transport and gradients in plants are mediated by influx and efflux carriers. PvPIN1, a switchgrass PIN1-like gene that is involved in regulating polar transport, is a putative auxin efflux carrier. Neighbor-joining analysis using sequences deposited in NCBI databases showed that the PvPIN1gene belongs to the PIN1 family and is evolutionarily closer to the Oryza sativa japonica group. Tiller emergence and development was significantly promoted in plants subjected toPvPIN1 RNA interference (RNAi, which yielded a phenotype similar to that of wild-type plants treated with the auxin transport inhibitor TIBA (2,3,5-triiodobenzoic acid. A transgenic approach that inducedPvPIN1 gene overexpression or suppression altered tiller number and the shoot/root ratio. These data suggest that PvPIN1plays an important role in auxin-dependent adventitious root emergence and tillering.

  7. Transcriptional analysis of defense mechanisms in upland tetraploid switchgrass to greenbugs.

    Science.gov (United States)

    Donze-Reiner, Teresa; Palmer, Nathan A; Scully, Erin D; Prochaska, Travis J; Koch, Kyle G; Heng-Moss, Tiffany; Bradshaw, Jeffrey D; Twigg, Paul; Amundsen, Keenan; Sattler, Scott E; Sarath, Gautam

    2017-02-16

    Aphid infestation of switchgrass (Panicum virgatum) has the potential to reduce yields and biomass quality. Although switchgrass-greenbug (Schizaphis graminum; GB) interactions have been studied at the whole plant level, little information is available on plant defense responses at the molecular level. The global transcriptomic response of switchgrass cv Summer to GB was monitored by RNA-Seq in infested and control (uninfested) plants harvested at 5, 10, and 15 days after infestation (DAI). Differentially expressed genes (DEGs) in infested plants were analyzed relative to control uninfested plants at each time point. DEGs in GB-infested plants induced by 5-DAI included an upregulation of reactive burst oxidases and several cell wall receptors. Expression changes in genes linked to redox metabolism, cell wall structure, and hormone biosynthesis were also observed by 5-DAI. At 10-DAI, network analysis indicated a massive upregulation of defense-associated genes, including NAC, WRKY, and MYB classes of transcription factors and potential ancillary signaling molecules such as leucine aminopeptidases. Molecular evidence for loss of chloroplastic functions was also detected at this time point. Supporting these molecular changes, chlorophyll content was significantly decreased, and ROS levels were elevated in infested plants 10-DAI. Total peroxidase and laccase activities were elevated in infested plants at 10-DAI relative to control uninfested plants. The net result appeared to be a broad scale defensive response that led to an apparent reduction in C and N assimilation and a potential redirection of nutrients away from GB and towards the production of defensive compounds, such as pipecolic acid, chlorogenic acid, and trehalose by 10-DAI. By 15-DAI, evidence of recovery in primary metabolism was noted based on transcript abundances for genes associated with carbon, nitrogen, and nutrient assimilation. Extensive remodeling of the plant transcriptome and the production of

  8. Toxicity of coal fly ash (CFA) and toxicological response of switchgrass in mycorrhiza-mediated CFA-soil admixtures.

    Science.gov (United States)

    Awoyemi, Olushola M; Dzantor, E Kudjo

    2017-10-01

    Increasing support for the use of Coal fly ash (CFA) in agriculture has necessitated a better understanding of the effects of the CFA in various cropping schemes. Experiments were conducted to assess mutagenic response of a mutant strain of Salmonella enterica serovar Typhimurium (TA100) to varying concentrations of CFA-water extracts, determine oxidative stress in switchgrass (Panicum virgatum L.) at varying levels of CFA-soil admixtures, and evaluate mycorrhiza-mediated modulation of oxidative stress responses of CFA-grown switchgrass. The TA100 exposed to 0%, 5%, 10%, 15%, 20% and 25% (w/v) CFA-water extracts elicited significant (p < 0.05) mutagenic responses at 20% and 25% extract levels but not below the 15% level. In greenhouse pot experiment, CFA-soil admixtures at 7.5% and 15% (w/w) significantly (p < 0.05) decreased the activities of superoxide dismutase (SOD) by 19.1% and 28.3% respectively, compared to control soil (0% w/w CFA/soil). Under the same conditions, activities of glutathione peroxidase (GPx) decreased by 75.9% and 66.9%. In contrast to the antioxidant enzyme activities, levels of malondialdehyde (MDA) an indicator of lipid peroxidation increased significantly (p < 0.05) by 30.49% and 38.38%. Inoculation of 7.5% and 15% CFA-soil admixtures with arbuscular mycorrhizal fungi (AMF), Rhizophaga clarus enhanced the activities of both SOD and GPx in the switchgrass, while it significantly (p < 0.05) reduced the levels of MDA. The study demonstrated that incorporation of CFA (at concentrations considered to be non-mutagenic against TA100) as soil amendment produced concentration-dependent oxidative stress responses in switchgrass; however, inoculation of the CFA-soil admixtures with AMF significantly modulated the oxidative stress responses. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Simultaneous Downregulation of MTHFR and COMT in Switchgrass Affects Plant Performance and Induces Lesion-Mimic Cell Death

    Directory of Open Access Journals (Sweden)

    Sijia Liu

    2017-06-01

    Full Text Available Switchgrass (Panicum virgatum has been developed into a model lignocellulosic bioenergy crop. Downregulation of caffeic acid O-methyltransferase (COMT, a key enzyme in lignin biosynthesis, has been shown to alter lignification and increase biofuel yield in switchgrass. Methylenetetrahydrofolate reductase (MTHFR mediates C1 metabolism and provides methyl units consumed by COMT. It was predicted that co-silencing of MTHFR and COMT would impact lignification even more than either of the single genes. However, our results showed that strong downregulation of MTHFR in a COMT-deficient background led to altered plant growth and development, but no significant change in lignin content or composition was found when compared with COMT plants. Another unexpected finding was that the double MTHFR/COMT downregulated plants showed a novel lesion-mimic leaf phenotype. Molecular analyses revealed that the lesion-mimic phenotype was caused by the synergistic effect of MTHFR and COMT genes, with MTHFR playing a predominant role. Microarray analysis showed significant induction of genes related to oxidative and defense responses. The results demonstrated the lack of additive effects of MTHFR and COMT on lignification. Furthermore, this research revealed an unexpected role of the two genes in the modulation of lesion-mimic cell death as well as their synergistic effects on agronomic performance.

  10. Evaluation of ammonia fibre expansion (AFEX) pretreatment for enzymatic hydrolysis of switchgrass harvested in different seasons and locations.

    Science.gov (United States)

    Bals, Bryan; Rogers, Chad; Jin, Mingjie; Balan, Venkatesh; Dale, Bruce

    2010-01-04

    When producing biofuels from dedicated feedstock, agronomic factors such as harvest time and location can impact the downstream production. Thus, this paper studies the effectiveness of ammonia fibre expansion (AFEX) pretreatment on two harvest times (July and October) and ecotypes/locations (Cave-in-Rock (CIR) harvested in Michigan and Alamo harvested in Alabama) for switchgrass (Panicum virgatum). Both harvest date and ecotype/location determine the pretreatment conditions that produce maximum sugar yields. There was a high degree of correlation between glucose and xylose released regardless of the harvest, pretreatment conditions, or enzyme formulation. Enzyme formulation that produced maximum sugar yields was the same across all harvests except for the CIR October harvest. The least mature sample, the July harvest of CIR switchgrass, released the most sugars (520 g/kg biomass) during enzymatic hydrolysis while requiring the least severe pretreatment conditions. In contrast, the most mature harvest released the least amount of sugars (410 g/kg biomass). All hydrolysates were highly fermentable, although xylose utilisation in the July CIR hydrolysate was poor. Each harvest type and location responded differently to AFEX pretreatment, although all harvests successfully produced fermentable sugars. Thus, it is necessary to consider an integrated approach between agricultural production and biochemical processing in order to insure optimal productivity.

  11. Evaluation of ammonia fibre expansion (AFEX pretreatment for enzymatic hydrolysis of switchgrass harvested in different seasons and locations

    Directory of Open Access Journals (Sweden)

    Balan Venkatesh

    2010-01-01

    Full Text Available Abstract Background When producing biofuels from dedicated feedstock, agronomic factors such as harvest time and location can impact the downstream production. Thus, this paper studies the effectiveness of ammonia fibre expansion (AFEX pretreatment on two harvest times (July and October and ecotypes/locations (Cave-in-Rock (CIR harvested in Michigan and Alamo harvested in Alabama for switchgrass (Panicum virgatum. Results Both harvest date and ecotype/location determine the pretreatment conditions that produce maximum sugar yields. There was a high degree of correlation between glucose and xylose released regardless of the harvest, pretreatment conditions, or enzyme formulation. Enzyme formulation that produced maximum sugar yields was the same across all harvests except for the CIR October harvest. The least mature sample, the July harvest of CIR switchgrass, released the most sugars (520 g/kg biomass during enzymatic hydrolysis while requiring the least severe pretreatment conditions. In contrast, the most mature harvest released the least amount of sugars (410 g/kg biomass. All hydrolysates were highly fermentable, although xylose utilisation in the July CIR hydrolysate was poor. Conclusions Each harvest type and location responded differently to AFEX pretreatment, although all harvests successfully produced fermentable sugars. Thus, it is necessary to consider an integrated approach between agricultural production and biochemical processing in order to insure optimal productivity.

  12. Evaluation of the bioconversion of genetically modified switchgrass using simultaneous saccharification and fermentation and a consolidated bioprocessing approach

    Directory of Open Access Journals (Sweden)

    Yee Kelsey L

    2012-11-01

    Full Text Available Abstract Background The inherent recalcitrance of lignocellulosic biomass is one of the major economic hurdles for the production of fuels and chemicals from biomass. Additionally, lignin is recognized as having a negative impact on enzymatic hydrolysis of biomass, and as a result much interest has been placed on modifying the lignin pathway to improve bioconversion of lignocellulosic feedstocks. Results Down-regulation of the caffeic acid 3-O-methyltransferase (COMT gene in the lignin pathway yielded switchgrass (Panicum virgatum that was more susceptible to bioconversion after dilute acid pretreatment. Here we examined the response of these plant lines to milder pretreatment conditions with yeast-based simultaneous saccharification and fermentation and a consolidated bioprocessing approach using Clostridium thermocellum, Caldicellulosiruptor bescii and Caldicellulosiruptor obsidiansis. Unlike the S. cerevisiae SSF conversions, fermentations of pretreated transgenic switchgrass with C. thermocellum showed an apparent inhibition of fermentation not observed in the wild-type switchgrass. This inhibition can be eliminated by hot water extraction of the pretreated biomass, which resulted in superior conversion yield with transgenic versus wild-type switchgrass for C. thermocellum, exceeding the yeast-based SSF yield. Further fermentation evaluation of the transgenic switchgrass indicated differential inhibition for the Caldicellulosiruptor sp. strains, which could not be rectified by additional processing conditions. Gas chromatography–mass spectrometry (GC-MS metabolite profiling was used to examine the fermentation broth to elucidate the relative abundance of lignin derived aromatic compounds. The types and abundance of fermentation-derived-lignin constituents varied between C. thermocellum and each of the Caldicellulosiruptor sp. strains. Conclusions The down-regulation of the COMT gene improves the bioconversion of switchgrass relative to the

  13. Different Effects of Corn Ethanol and Switchgrass-Based Biofuels on Soil Erosion and Nutrients Loads in the Iowa River Basin

    Science.gov (United States)

    Wu, Y.; Liu, S.

    2010-12-01

    Biofuels have become important alternative energy resources and their use is likely to expand in the foreseeable future. The expansion of corn-based ethanol production has resulted in a tightening of the global corn supply-and-demand balance. Perennial grasses such as switchgrass (Panicum virgatum) are also being considered as candidates for biofuel feedstocks. Expansion of biofuel production will generate diverse impacts on the economy and environment. How to optimize land use activities to address the need for biofuel production while protecting the environment is still a grand challenge. Unfortunately, little is known about the effects of biofuel-oriented alternative land uses on water quality. Can we produce the same amount or more biofuels by converting some cornfields to switchgrass, for example, while reducing environmental pressure? The objective of this study was to evaluate the potential impacts of land cover change from corn to switchgrass (e.g., on marginal lands) and related management activities on water quality in the Iowa River Basin (drainage area of 32,360 km2) using the Soil and Water Assessment Tool (SWAT). The model was calibrated and validated under baseline conditions using daily streamflow and sediment, and monthly nutrients at Wapello, Iowa (near the outlet of the watershed). The preliminary results show that both the annual average sediment yield and nitrate nitrogen load would decrease when marginal corn areas are converted to switchgrass. However, the magnitude of change depends greatly on the detailed management practices, such as techniques and amount of fertilization, harvesting practices, and residue management.

  14. Developing Switchgrass as a Bioenergy Crop

    Energy Technology Data Exchange (ETDEWEB)

    Bouton, J.; Bransby, D.; Conger, B.; McLaughlin, S.; Ocumpaugh, W.; Parrish, D.; Taliaferro, C.; Vogel, K.; Wullschleger, S.

    1998-11-08

    The utilization of energy crops produced on American farms as a source of renewable fuels is a concept with great relevance to current ecological and economic issues at both national and global scales. Development of a significant national capacity to utilize perennial forage crops, such as switchgrass (Panicum virgatum, L.) as biofuels could benefit our agricultural economy by providing an important new source of income for farmers. In addition energy production from perennial cropping systems, which are compatible with conventional fining practices, would help reduce degradation of agricultural soils, lower national dependence on foreign oil supplies, and reduce emissions of greenhouse gases and toxic pollutants to the atmosphere (McLaughlin 1998). Interestingly, on-farm energy production is a very old concept, extending back to 19th century America when both transpofiation and work on the farm were powered by approximately 27 million draft animals and fueled by 34 million hectares of grasslands (Vogel 1996). Today a new form of energy production is envisioned for some of this same acreage. The method of energy production is exactly the same - solar energy captured in photosynthesis, but the subsequent modes of energy conversion are vastly different, leading to the production of electricity, transportation fuels, and chemicals from the renewable feedstocks. While energy prices in the United States are among the cheapest in the world, the issues of high dependency on imported oil, the uncertainties of maintaining stable supplies of imported oil from finite reserves, and the environmental costs associated with mining, processing, and combusting fossil fuels have been important drivers in the search for cleaner burning fuels that can be produced and renewed from the landscape. At present biomass and bioenergy combine provide only about 4% of the total primary energy used in the U.S. (Overend 1997). By contrast, imported oil accounts for approximately 44% of the

  15. Switchgrass cultivar EG1102

    Energy Technology Data Exchange (ETDEWEB)

    Bouton, Joseph H; Wood, Donald T

    2012-11-20

    A switchgrass cultivar designated EG1102 is disclosed. The invention relates to the seeds of switchgrass cultivar EG1102, to the plants of switchgrass EG1102, to plant parts of switchgrass cultivar EG1102 and to methods for producing a switchgrass plant produced by crossing switchgrass cultivar EG1102 with itself or with another switchgrass variety. The invention also relates to methods for producing a switchgrass plant containing in its genetic material one or more transgenes and to the transgenic switchgrass plants and plant parts produced by those methods. This invention also relates to switchgrass cultivars or breeding cultivars and plant parts derived from switchgrass variety EG1102, to methods for producing other switchgrass cultivars, lines or plant parts derived from switchgrass cultivar EG1102 and to the switchgrass plants, varieties, and their parts derived from use of those methods. The invention further relates to hybrid switchgrass seeds, plants and plant parts produced by crossing the cultivar EG1102 with another switchgrass cultivar.

  16. Switchgrass cultivar EG1101

    Energy Technology Data Exchange (ETDEWEB)

    Bouton, Joseph H; Wood, Donald T

    2012-11-27

    A switchgrass cultivar designated EG1101 is disclosed. Also disclosed are seeds of switchgrass cultivar EG1101, plants of switchgrass EG1101, plant parts of switchgrass cultivar EG1101 and methods for producing a switchgrass plant produced by crossing switchgrass cultivar EG1101 with itself or with another switchgrass variety. Methods are also described for producing a switchgrass plant containing in its genetic material one or more transgenes and to the transgenic switchgrass plants and plant parts produced by those methods. Switchgrass cultivars or breeding cultivars and plant parts derived from switchgrass variety EG1101, methods for producing other switchgrass cultivars, lines or plant parts derived from switchgrass cultivar EG1101 and the switchgrass plants, varieties, and their parts derived from use of those methods are described herein. Hybrid switchgrass seeds, plants and plant parts produced by crossing the cultivar EG1101 with another switchgrass cultivar are also described.

  17. Switchgrass biomass energy storage project. Final report, September 23, 1996--December 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Miller, G.A.; Teel, A.; Brown, S.S. [Iowa State Univ., Ames, IA (United States)

    1996-07-01

    The Chariton Valley Biomass Power Project, sponsored by the Chariton Valley RC&D Inc., a USDA-sponsored rural development organization, the Iowa Department of Natural Resources Energy Bureau (IDNR-EB), and IES Utilities, a major Iowa energy company, is directed at the development of markets for energy crops in southern Iowa. This effort is part of a statewide coalition of public and private interests cooperating to merge Iowa`s agricultural potential and its long-term energy requirements to develop locally sustainable sources of biomass fuel. The four-county Chariton Valley RC&D area (Lucas, Wayne, Appanoose and Monroe counties) is the site of one of eleven NREL/EPRI feasibility studies directed at the potential of biomass power. The focus of renewable energy development in the region has centered around the use of swithgrass (Panicum virgatum, L.). This native Iowa grass is one of the most promising sustainable biomass fuel crops. According to investigations by the U.S. Department of Energy (DOE), switchgrass has the most potential of all the perennial grasses and legumes evaluated for biomass production.

  18. Deciphering Natural Allelic Variation in Switchgrass for Biomass Yield and Quality Using a Nested Association Mapping Population

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Malay C. [The Samuel Roberts Noble Foundation, Inc., Ardmore, OK (United States). Forage Improvement Division (FID); Brummer, E. Charles [The Samuel Roberts Noble Foundation, Inc., Ardmore, OK (United States); Kaeppler, Shawn [Univ. of Wisconsin, Madison, WI (United States); Bhandari, Hem S. [Univ. of Tennessee, Knoxville, TN (United States)

    2016-10-28

    Switchgrass (Panicum virgatum L.) is a C4 grass with high biomass yield potential and a model species for bioenergy feedstock development. Understanding the genetic basis of quantitative traits is essential to facilitate genome-enabled breeding programs. The nested association mapping (NAM) analysis combines the best features of both bi-parental and association analyses and can provide high power and high resolution in QTL detection and will ensure significant improvements in biomass yield and quality. To develop a NAM population of switchgrass, 15 highly diverse genotypes with specific characteristics were selected from a diversity panel and crossed to a recurrent parent, AP13, a genotype selected for whole genome sequencing and parent of a mapping population. Ten genotypes from each of the 15 F1 families were then chain crossed. Progenies form each family were randomly selected to develop the NAM population. The switchgrass NAM population consists of a total of 2000 genotypes from 15 families. All the progenies, founder parents, F1 parents (n=2350) were evaluated in replicated field trials at Ardmore, OK and Knoxville, TN. Phenotypic data on plant height, tillering ability, regrowth, flowering time, and biomass yield were collected. Dried biomass samples were also analyzed using prediction equations of NIRS at the Noble Foundation and for lignin content, S/G ratio, and sugar release characteristics at the NREL. Genomic shotgun sequencing of 15 switchgrass NAM founder parental genomes at JGI produced 28-66 Gb high-quality sequence data. Alignment of these sequences with the reference genome, AP13 (v3.0), revealed that up to 99% of the genomic sequences mapped to the reference genome. A total of 2,149 individuals from NAM populations were sequenced by exome capture and two sets of 15 SNP matrices (one for each family) were generated. QTL associated with important traits have been identified and verified in breeding populations. The QTL detected and their associated

  19. Down-regulation of the caffeic acid O-methyltransferase gene in switchgrass reveals a novel monolignol analog

    Directory of Open Access Journals (Sweden)

    Tschaplinski Timothy J

    2012-09-01

    Full Text Available Abstract Background Down-regulation of the caffeic acid 3-O-methyltransferase EC 2.1.1.68 (COMT gene in the lignin biosynthetic pathway of switchgrass (Panicum virgatum resulted in cell walls of transgenic plants releasing more constituent sugars after pretreatment by dilute acid and treatment with glycosyl hydrolases from an added enzyme preparation and from Clostridium thermocellum. Fermentation of both wild-type and transgenic switchgrass after milder hot water pretreatment with no water washing showed that only the transgenic switchgrass inhibited C. thermocellum. Gas chromatography–mass spectrometry (GCMS-based metabolomics were undertaken on cell wall aqueous extracts to determine the nature of the microbial inhibitors. Results GCMS confirmed the increased concentration of a number of phenolic acids and aldehydes that are known inhibitors of microbial fermentation. Metabolomic analyses of the transgenic biomass additionally revealed the presence of a novel monolignol-like metabolite, identified as trans-3, 4-dimethoxy-5-hydroxycinnamyl alcohol (iso-sinapyl alcohol in both non-pretreated, as well as hot water pretreated samples. iso-Sinapyl alcohol and its glucoside were subsequently generated by organic synthesis and the identity of natural and synthetic materials were confirmed by mass spectrometric and NMR analyses. The additional novel presence of iso-sinapic acid, iso-sinapyl aldehyde, and iso-syringin suggest the increased activity of a para-methyltransferase, concomitant with the reduced COMT activity, a strict meta-methyltransferase. Quantum chemical calculations were used to predict the most likely homodimeric lignans generated from dehydration reactions, but these products were not evident in plant samples. Conclusions Down-regulation of COMT activity in switchgrass resulted in the accumulation of previously undetected metabolites resembling sinapyl alcohol and its related metabolites, but that are derived from para

  20. Improved tissue culture conditions for the emerging C4model Panicum hallii.

    Science.gov (United States)

    Grant, Joshua N; Burris, Jason N; Stewart, C Neal; Lenaghan, Scott C

    2017-04-27

    Panicum hallii Vasey (Hall's panicgrass) is a compact, perennial C 4 grass in the family Poaceae, which has potential to enable bioenergy research for switchgrass (Panicum virgatum L.). Unlike P. hallii, switchgrass has a large genome, allopolyploidy, self-incompatibility, a long life cycle, and large stature-all suboptimal traits for rapid genetics research. Herein we improved tissue culture methodologies for two inbred P. hallii populations: FIL2 and HAL2, to enable further development of P. hallii as a model C 4 plant. The optimal seed-derived callus induction medium was determined to be Murashige and Skoog (MS) medium supplemented with 40 mg L -1 L-cysteine, 300 mg L -1 L-proline, 3% sucrose, 1 g L -1 casein hydrolysate, 3 mg L -1 2,4-dichlorophenoxyacetic acid (2,4-D), and 45 μg L -1 6-benzylaminopurine (BAP), which resulted in callus induction of 51 ± 29% for FIL2 and 81 ± 19% for HAL2. The optimal inflorescence-derived callus induction was observed on MP medium (MS medium supplemented with 2 g L -1 L-proline, 3% maltose, 5 mg L -1 2,4-D, and 500 μg L -1 BAP), resulting in callus induction of 100 ± 0.0% for FIL2 and 84 ± 2.4% for HAL2. Shoot regeneration rates of 11.5 ± 0.8 shoots/gram for FIL2 and 11.3 ± 0.6 shoots/gram for HAL2 were achieved using seed-induced callus, whereas shoot regeneration rates of 26.2 ± 2.6 shoots/gram for FIL2 and 29.3 ± 3.6 shoots/gram for HAL2 were achieved from inflorescence-induced callus. Further, cell suspension cultures of P. hallii were established from seed-derived callus, providing faster generation of callus tissue compared with culture using solidified media (1.41-fold increase for FIL2 and 3.00-fold increase for HAL2). Aside from abbreviated tissue culture times from callus induction to plant regeneration for HAL2, we noted no apparent differences between FIL2 and HAL2 populations in tissue culture performance. For both populations, the cell suspension cultures

  1. Utility of remote sensing-based surface energy balance models to track water stress in rain-fed switchgrass under dry and wet conditions

    Science.gov (United States)

    Bhattarai, Nishan; Wagle, Pradeep; Gowda, Prasanna H.; Kakani, Vijaya G.

    2017-11-01

    The ability of remote sensing-based surface energy balance (SEB) models to track water stress in rain-fed switchgrass (Panicum virgatum L.) has not been explored yet. In this paper, the theoretical framework of crop water stress index (CWSI; 0 = extremely wet or no water stress condition and 1 = extremely dry or no transpiration) was utilized to estimate CWSI in rain-fed switchgrass using Landsat-derived evapotranspiration (ET) from five remote sensing based single-source SEB models, namely Surface Energy Balance Algorithm for Land (SEBAL), Mapping ET with Internalized Calibration (METRIC), Surface Energy Balance System (SEBS), Simplified Surface Energy Balance Index (S-SEBI), and Operational Simplified Surface Energy Balance (SSEBop). CWSI estimates from the five SEB models and a simple regression model that used normalized difference vegetation index (NDVI), near-surface temperature difference, and measured soil moisture (SM) as covariates were compared with those derived from eddy covariance measured ET (CWSIEC) for the 32 Landsat image acquisition dates during the 2011 (dry) and 2013 (wet) growing seasons. Results indicate that most SEB models can predict CWSI reasonably well. For example, the root mean square error (RMSE) ranged from 0.14 (SEBAL) to 0.29 (SSEBop) and the coefficient of determination (R2) ranged from 0.25 (SSEBop) to 0.72 (SEBAL), justifying the added complexity in CWSI modeling as compared to results from the simple regression model (R2 = 0.55, RMSE = 0.16). All SEB models underestimated CWSI in the dry year but the estimates from SEBAL and S-SEBI were within 7% of the mean CWSIEC and explained over 60% of variations in CWSIEC. In the wet year, S-SEBI mostly overestimated CWSI (around 28%), while estimates from METRIC, SEBAL, SEBS, and SSEBop were within 8% of the mean CWSIEC. Overall, SEBAL was the most robust model under all conditions followed by METRIC, whose performance was slightly worse and better than SEBAL in dry and wet years

  2. Direct mechanical energy measures of hammer mill comminution of switchgrass, wheat straw, and corn stover and analysis of their particle size distributions

    Energy Technology Data Exchange (ETDEWEB)

    Bitra, V.S.P [University of Tennessee; Womac, A.R. [University of Tennessee; Chevanan, Nehru [University of Tennessee; Miu, P.I. [University of Tennessee; Smith, D.R. [University of Tennessee; Igathinathane, C. [Mississippi State University (MSU); Sokhansanj, Shahabaddine [ORNL

    2009-07-01

    Biomass particle size impacts handling, storage, conversion, and dust control systems. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented hammer mill. Direct energy inputs were determined for hammer mill operating speeds from 2000 to 3600 rpm for 3.2 mm integral classifying screen and mass input rate of 2.5 kg/min with 90 - and 30 -hammers. Overall accuracy of specific energy measurement was calculated as 0.072 MJ/Mg. Particle size distributions created by hammer mill were determined for mill operating factors using ISO sieve sizes from 4.75 to 0.02 mm in conjunction with Ro-Tap sieve analyzer. A wide range of analytical descriptors were examined to mathematically represent the range of particle sizes in the distributions. Total specific energy (MJ/Mg) was defined as size reduction energy to operate the hammer mill plus that imparted to biomass. Effective specific energy was defined as energy imparted to biomass. Total specific energy for switchgrass, wheat straw, and corn stover grinding increased by 37, 30, and 45% from 114.4, 125.1, and 103.7 MJ/Mg, respectively, with an increase in hammer mill speed from 2000 to 3600 rpm for 90 -hammers. Corresponding total specific energy per unit size reduction was 14.9, 19.7, and 13.5 MJ/Mg mm, respectively. Effective specific energy of 90 -hammers decreased marginally for switchgrass and considerably for wheat straw and it increased for corn stover with an increase in speed from 2000 to 3600 rpm. However, effective specific energy increased with speed to a certain extent and then decreased for 30 -hammers. Rosin Rammler equation fitted the size distribution data with R2 > 0.995. Mass relative span was greater than 1, which indicated a wide distribution of particle sizes. Hammer milling of switchgrass, wheat straw, and corn stover with 3.2 mm screen resulted in well-graded fine-skewed mesokurtic

  3. Nutrient uptake of ornamental plants exposed to arsenic in hydroponic solution

    Science.gov (United States)

    Arsenic-based agro-chemicals have contaminated considerable acreage on turf-farms, orchards, and around horticultural production structures. A study was undertaken to evaluate iris (Iris virginica), switchgrass (Panicum virgatum), Tithonia rotundiflora, Coreopsis lanceolata, Sunflower (Helianthus an...

  4. The Hunt for Green Every April: Factors Affecting Fitness in Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Sarath, Gautam [US Dept. of Agriculture (USDA), Lincoln, NE (United States). Agricultural Research Service (ARS). Wheat, Sorghum and Forage Research

    2014-12-10

    This grant funded work was undertaken to develop fundamental biological knowledge of the factors affecting the complex plant trait “fitness” in switchgrass (Panicum virgatum L.), a plant being developed as a biomass crop. Using a diverse range of latitudinally-adapted switchgrass plants, genomic, molecular and physiological studies were performed to track a number of different aspects of plant genetics and physiology over the course of the growing season. Work was performed on both genetically unrelated and genetically related plants. Plants were established in the field from seedlings raised in a greenhouse, or from clones present in other field nurseries. Field grown plants were used as the source of all tissues. The three objectives of this proposal were:(1) Transcript Profiling, Metabolomics, and C and N Partitioning and Recycling in Crowns and Rhizomes of Switchgrass over two growing seasons; (2) Gene Profiling During Regreening and Dormancy of Bulked Segregants; (3) Extent of Linkage Disequilibrium in Populations for Adaptation and Fitness Traits Being Developed for Central and Northern USA, that Show Significant Heterosis. Objective 1 results: Plants were labeled using 13CO2 (a stable isotope) using an acrylic chamber constructed specifically for this purpose. Plants became labeled with 13C and label decayed in aerial tissues over the course of the growing season. Varying amounts of 13C were recovered in the rhizomes. These data are being analyzed. Plants were also labeled with 15N-urea. Plants absorbed significant amounts of label that was remobilized to the growing shoots. N-dynamics would suggest that a portion of the 15N absorbed into the crowns and rhizomes is sequestered below ground. Variable amounts of 15N were translocated from the shoots to the roots over the course of the growing season. Polar metabolites extracted from a diverse array of rhizomes were analyzed using GCMS. Data

  5. Performance of sheep grazing Brachiaria decumbens, Panicum ...

    African Journals Online (AJOL)

    Performance of sheep grazing Brachiaria decumbens, Panicum maximum and Pennisetum purpureum in combination with gliricidia sepium. ... The animals weregrazed continuously for 28 days in the sub plots. Sheep grazing the Gliricidia/Panicum plot had a higher (P < 001) growth rate (38 g d-1) than those animals ...

  6. Switchgrass for ethanol and lipid production

    Science.gov (United States)

    Switchgrass is being developed as a dedicated cellulosic biomass crop by the Agricultural Research Service (ARS). Switchgrass is a native prairie grass with high productivity and favorable agronomic traits. ARS researchers have recently released Liberty switchgrass, which has a 25-78% increase in bi...

  7. Impact of mechanical, chemical and enzymatic pre-treatments on the methane yield from the anaerobic digestion of switchgrass

    International Nuclear Information System (INIS)

    Frigon, Jean-Claude; Mehta, Punita; Guiot, Serge R.

    2012-01-01

    The conversion of cellulosic crops into biofuels, including methane, is receiving a lot of attention lately. Panicum vergatum, or switchgrass, is a warm season perennial grass well adapted to grow in North America. Different pre-treatments were tested in 0.5 l batch reactors, at 35 °C, in order to enhance the methane production from switchgrass, including temperature, sonication, alkalinization and autoclaving. The methane production on the basis of volatile solids (VS) added to the fermentation were 112.4 ± 8.4, 132.5 ± 9.7 and 139.8 ml g −1 after 38 days of incubation for winter harvested switchgrass (WHS) after grinding, grinding with alkalinization, and grinding with alkalinization and autoclaving, respectively. The methane production was higher for fresh summer harvested switchgrass (SHS), with a production of 256.6 ± 8.2 ml g −1 VS after mulching, alkalinization and autoclaving. The methane production from SHS was improved by 29 and 42% when applying lignin (LiP) or manganese peroxidase (MnP), at 202.1 ± 9.8 and 222.9 ± 22.5 ml g −1 VS, respectively. The combination of an alkali pre-treatment with the MnP increased the methane production furthermore at 297.7 ml g −1 VS. The use of pectinases without chemical pre-treatment showed promising yields at 287.4 and 239.5 ml g −1 VS for pectate-lyase and poly-galacturonase, respectively. An estimation of the methane yield per hectare of crop harvested resulted in net energy production of 29.8, 49.7 and 78.1 GJ for winter harvested switchgrass, mulched and pretreated summer harvested switchgrass, respectively. Switchgrass represents an interesting candidate as a lignocellulosic crop for methane production. -- Highlights: ► Switchgrass is a model energy crops for biofuels production. ► This study evaluated different pre-treatments to enhance methane production. ► Pre-treatments increase significantly the methane produced from switchgrass. ► Enzymatic pre-treatments were superior to physical and

  8. The Switchgrass Genome: Tools and Strategies

    Directory of Open Access Journals (Sweden)

    Michael D. Casler

    2011-11-01

    Full Text Available Switchgrass ( L. is a perennial grass species receiving significant focus as a potential bioenergy crop. In the last 5 yr the switchgrass research community has produced a genetic linkage map, an expressed sequence tag (EST database, a set of single nucleotide polymorphism (SNP markers that are distributed across the 18 linkage groups, 4x sampling of the AP13 genome in 400-bp reads, and bacterial artificial chromosome (BAC libraries containing over 200,000 clones. These studies have revealed close collinearity of the switchgrass genome with those of sorghum [ (L. Moench], rice ( L., and (L. P. Beauv. Switchgrass researchers have also developed several microarray technologies for gene expression studies. Switchgrass genomic resources will accelerate the ability of plant breeders to enhance productivity, pest resistance, and nutritional quality. Because switchgrass is a relative newcomer to the genomics world, many secrets of the switchgrass genome have yet to be revealed. To continue to efficiently explore basic and applied topics in switchgrass, it will be critical to capture and exploit the knowledge of plant geneticists and breeders on the next logical steps in the development and utilization of genomic resources for this species. To this end, the community has established a switchgrass genomics executive committee and work group ( [verified 28 Oct. 2011].

  9. Delignification of Switchgrass Cultivars for Bioethanol Production

    Science.gov (United States)

    Three switchgrass cultivars (‘Performer’, ‘BoMaster’, and ‘Colony’ switchgrass) were delignified using NaOH at varying concentrations and residence times at 121 oC for improved sugar production in enzymatic hydrolysis. Because of its greater carbohydrate/lignin ratio and the more substantial lignin ...

  10. Transport biofuel yields from food and lignocellulosic C4 crops

    NARCIS (Netherlands)

    Reijnders, L.

    2010-01-01

    In the near future, the lignocellulosic C4 crops Miscanthus and switchgrass (Panicum virgatum) are unlikely to outcompete sugarcane (Saccharum officinarum) in net energetic yearly yield of transport biofuel ha(-1). This holds both for the thermochemical conversion into liquid hydrocarbons and the

  11. The water quality and quantity effects of biofuel operations in pine plantations of the southeastern USA

    Science.gov (United States)

    J. Nettles; M. Youssef; J. Cacho; J. Grace; Z. Leggett; E. Sucre

    2011-01-01

    Working alongside operational trials, a comprehensive research programme was developed to evaluate sustainability, life-cycle analysis, soil productivity, wildlife, and water resource impacts. The hydrology field studies consist of three sets of forested watersheds, each with mid-rotation pine reference, switchgrass (Panicum virgatum) interplanted, typical...

  12. Impacts of managing perennial grasses in the northern Midwest United States for bioenergy on soil organic C and nitrous oxide emission

    Science.gov (United States)

    In the USA perennial grasses [e.g., switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman)] are proposed as cellulosic feedstock. Perennial grasses are often touted as being low input and as having a C-neutral foot print, but managing them as bioenergy feedstock means addin...

  13. The effect of five biomass cropping systems on soil-saturated hydraulic conductivity across a topographic gradient

    Science.gov (United States)

    Usman Anwar; Lisa A. Schulte; Matthew Helmers; Randall K. Kolka

    2017-01-01

    Understanding the environmental impact of bioenergy crops is needed to inform bioenergy policy development. We determined the effects of five biomass cropping systems—continuous maize (Zea mays), soybean (Glycine max)-triticale (Triticosecale ×)/soybean-maize, maize-switchgrass (Panicum virgatum...

  14. Chemistry and microbial functional diversity differences in biofuel crop and grassland soils in multiple geographies

    Science.gov (United States)

    As crop and non-crop lands are increasingly becoming converted to biofuel feedstock production, it is of interest to identify potential impacts of annual and perennial feedstocks on soil ecosystem services. Soil samples obtained from 6 regional sets of switchgrass (Panicum virgatum L.) and 3 regiona...

  15. Modeling phosphorus capture by plants growing in a multi-species riparian buffer

    Science.gov (United States)

    The NST 3.0 mechanistic nutrient uptake model was used to explore phosphorus (P) uptake to a depth of 120 cm over a 126-d growing season in simulated buffer communities composed of mixtures of cottonwood (Populus deltoids Bartr.), switchgrass (Panicum virgatum L.), and smooth brome (Bromis inermis L...

  16. Evaluation of pulp and paper making characteristics of elephant ...

    African Journals Online (AJOL)

    Shortage of conventional raw material for the pulp and paper products together with the increasing world demand for paper has renewed interest in non-wood fibres. Non-wood pulping capacity has been increasing steadily over the last decade. A lot of crops grown for biomass, like switchgrass (Panicum virgatum L.), are ...

  17. Soil organic matter fractions in loblolly pine forests of Coastal North Carolina managed for bioenergy production

    Science.gov (United States)

    Kevan J. Minick; Brian D. Strahm; Thomas R. Fox; Eric B. Surce; Zakiya H. Leggett

    2015-01-01

    Dependence on foreign oil continues to increase, and concern over rising atmospheric CO2 and other greenhouse gases has intensified research into sustainable biofuel production. Intercropping switchgrass (Panicum virgatum L.) between planted rows of loblolly pine (Pinus taeda L.) offers an opportunity to utilize inter-row space that typically contains herbaceous and...

  18. Nitrous oxide emission and soil carbon sequestration from herbaceous perennial biofuel feedstocks

    Science.gov (United States)

    Greenhouse gas (GHG) mitigation and renewable, domestic fuels are needed in the United States. Switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman) are potential bioenergy feedstocks that may meet this need. However, managing perennial grasses for feedstock requires nitro...

  19. Switchgrass a valuable biomass crop for energy

    CERN Document Server

    2012-01-01

    The demand of renewable energies is growing steadily both from policy and from industry which seeks environmentally friendly feed stocks. The recent policies enacted by the EU, USA and other industrialized countries foresee an increased interest in the cultivation of energy crops; there is clear evidence that switchgrass is one of the most promising biomass crop for energy production and bio-based economy and compounds. Switchgrass: A Valuable Biomass Crop for Energy provides a comprehensive guide to  switchgrass in terms of agricultural practices, potential use and markets, and environmental and social benefits. Considering this potential energy source from its biology, breed and crop physiology to its growth and management to the economical, social and environmental impacts, Switchgrass: A Valuable Biomass Crop for Energy brings together chapters from a range of experts in the field, including a foreword from Kenneth P. Vogel, to collect and present the environmental benefits and characteristics of this a ...

  20. Micro-mesh fabric pollination bags for switchgrass

    Science.gov (United States)

    Pollination bags for making controlled crosses between switchgrass plants were made from a polyester micro-mesh fabric with a mesh size of 41 µm which is smaller than the mean reported 43 µm diameter of switchgrass pollen. When used in paired plant crosses between switchgrass plants, the mean amoun...

  1. Production of deuterated switchgrass by hydroponic cultivation.

    Science.gov (United States)

    Evans, Barbara R; Bali, Garima; Foston, Marcus; Ragauskas, Arthur J; O'Neill, Hugh M; Shah, Riddhi; McGaughey, Joseph; Reeves, David; Rempe, Caroline S; Davison, Brian H

    2015-07-01

    The bioenergy crop switchgrass was grown hydroponically from tiller cuttings in 50 % D 2 O to obtain biomass with 34 % deuterium substitution and physicochemical properties similar to those of H 2 O-grown switchgrass controls. Deuterium enrichment of biological materials can potentially enable expanded experimental use of small angle neutron scattering (SANS) to investigate molecular structural transitions of complex systems such as plant cell walls. Two key advances have been made that facilitate cultivation of switchgrass, an important forage and biofuel crop, for controlled isotopic enrichment: (1) perfusion system with individual chambers and (2) hydroponic growth from tiller cuttings. Plants were grown and maintained for several months with periodic harvest. Photosynthetic activity was monitored by measurement of CO2 in outflow from the growth chambers. Plant morphology and composition appeared normal compared to matched controls grown with H2O. Using this improved method, gram quantities of switchgrass leaves and stems were produced by continuous hydroponic cultivation using growth medium consisting of basal mineral salts in 50 % D2O. Deuterium incorporation was confirmed by detection of the O-D and C-D stretching peaks with FTIR and quantified by (1)H- and (2)H-NMR. This capability to produce deuterated lignocellulosic biomass under controlled conditions will enhance investigation of cell wall structure and its deconstruction by neutron scattering and NMR techniques.

  2. Microwave pretreatment of switchgrass for bioethanol production

    Science.gov (United States)

    Keshwani, Deepak Radhakrishin

    Lignocellulosic materials are promising alternative feedstocks for bioethanol production. These materials include agricultural residues, cellulosic waste such as newsprint and office paper, logging residues, and herbaceous and woody crops. However, the recalcitrant nature of lignocellulosic biomass necessitates a pretreatment step to improve the yield of fermentable sugars. The overall goal of this dissertation is to expand the current state of knowledge on microwave-based pretreatment of lignocellulosic biomass. Existing research on bioenergy and value-added applications of switchgrass is reviewed in Chapter 2. Switchgrass is an herbaceous energy crop native to North America and has high biomass productivity, potentially low requirements for agricultural inputs and positive environmental impacts. Based on results from test plots, yields in excess of 20 Mg/ha have been reported. Environmental benefits associated with switchgrass include the potential for carbon sequestration, nutrient recovery from run-off, soil remediation and provision of habitats for grassland birds. Published research on pretreatment of switchgrass reported glucose yields ranging from 70-90% and xylose yields ranging from 70-100% after hydrolysis and ethanol yields ranging from 72-92% after fermentation. Other potential value-added uses of switchgrass include gasification, bio-oil production, newsprint production and fiber reinforcement in thermoplastic composites. Research on microwave-based pretreatment of switchgrass and coastal bermudagrass is presented in Chapter 3. Pretreatments were carried out by immersing the biomass in dilute chemical reagents and exposing the slurry to microwave radiation at 250 watts for residence times ranging from 5 to 20 minutes. Preliminary experiments identified alkalis as suitable chemical reagents for microwave-based pretreatment. An evaluation of different alkalis identified sodium hydroxide as the most effective alkali reagent. Under optimum pretreatment

  3. Microbiological Quality of Panicum maximum Grass Silage with Addition of Lactobacillus sp. as Starter

    Science.gov (United States)

    Sumarsih, S.; Sulistiyanto, B.; Utama, C. S.

    2018-02-01

    The aim of the research was to evaluate microbiological quality of Panicum maximum grass silage with addition Lactobacillus sp as starter. The completely randomized design was been used on this research with 4 treaments and 3 replications. The treatments were P0 ( Panicum maximum grass silage without addition Lactobacillus sp ), P1 ( Panicum maximum grass silage with 2% addition Lactobacillus sp), P2 (Panicum maximum grass silage with 4% addition Lactobacillus sp) and P3 (Panicum maximum grass silage with 6% addition Lactobacillus sp).The parameters were microbial populations of Panicum maximum grass silage (total lactic acid bacteria, total bacteria, total fungi, and Coliform bacteria. The data obtained were analyzed variance (ANOVA) and further tests performed Duncan’s Multiple Areas. The population of lactic acid bacteria was higher (PMicrobiological quality of Panicum maximum grass silage with addition Lactobacillus sp was better than no addition Lactobacillus sp.

  4. Microelement contents of two Panicum maximum varieties as ...

    African Journals Online (AJOL)

    A study was carried out to determine the influence of variety, manure type and season on the micro mineral content of two P. maximum varieties. The trial included: two Panicum varieties (Local and Ntchisi), three manure types (cattle dung, swine dung and poultry droppings) plus control (No manure) and two seasons (rainy ...

  5. The regulation of starch accumulation in Panicum maximum Jacq ...

    African Journals Online (AJOL)

    Electron microscopic studies of Panicum maximum (PCK C4 photosynthetic type) when grown under controlled growth conditions as low nutrient nitrogen (20 ppm N, KNO3) showed interesting second order bundle sheath cell organisation: the cells were several times bigger than the mesophyll cells and were packed with ...

  6. Molecular markers linked to apomixis in Panicum maximum Jacq ...

    African Journals Online (AJOL)

    Panicum maximum Jacq. is an important forage grass of African origin largely used in the tropics. The genetic breeding of this species is based on the hybridization of sexual and apomictic genotypes and selection of apomictic F1 hybrids. The objective of this work was to identify molecular markers linked to apomixis in P.

  7. The regulation of starch accumulation in Panicum maximum Jacq ...

    African Journals Online (AJOL)

    ... decrease the starch level. These observations are discussed in relation to the photosynthetic characteristics of P. maximum. Keywords: accumulation; botany; carbon assimilation; co2 fixation; growth conditions; mesophyll; metabolites; nitrogen; nitrogen levels; nitrogen supply; panicum maximum; plant physiology; starch; ...

  8. Anti-nutrient components of guinea grass ( Panicum maximum ...

    African Journals Online (AJOL)

    This research was carried out in 2004 in the Department of Crop Science, University of Nigeria, Nsukka. The study investigated the anti-quality factors in Panicum maximum under different N-fertilizer application rates and cutting management. The experiment was a 4 × 4 factorial laid out in a randomized complete block ...

  9. Estruturas silicosas na gramínea Panicum maximum

    Directory of Open Access Journals (Sweden)

    Pedro Fontana Junior

    1957-05-01

    Full Text Available The silica structure of the grass Panicum maximum were studied by electron and phase contrast microscopy. Several interesting kinds of silica formation (spiklets were found. The most ineresting structures ressembels the "Schaumstruktur" found by HELMCKE in diatoms. Another interesting structure was described in the "silica cells" and a detailed study of the mophology of some different kinds of spiklets was made.

  10. Performance of weaner rabbits fed Panicum maximum, Centrosema ...

    African Journals Online (AJOL)

    Sixteen Crossbred Weaner rabbits aged eight weeks made up of 8 males and 8 females with initial average weight of 650 ± 21.76 g were subjected to four dietary treatments namely Panicum maximum plus Poultry growers mash (T1), Centrosema pubescens plus Poultry growers mash (T2) Sida acuta plus Poultry growers ...

  11. Potential for nitrogen fixation and biomass production in Panicum ...

    African Journals Online (AJOL)

    Azospirillum sp. contributed approximately 48 per cent of total aerobic counts and was found to be capabl e of growth under strictly anaerobic conditions where it constituted about 11 per cent of total counts. Panicum maximum was found to be capable of growth in soils of clay-loam, sandyclay or purely loam types with pH ...

  12. Response of switchgrass yield to future climate change

    International Nuclear Information System (INIS)

    Tulbure, Mirela G; Wimberly, Michael C; Owens, Vance N

    2012-01-01

    A climate envelope approach was used to model the response of switchgrass, a model bioenergy species in the United States, to future climate change. The model was built using general additive models (GAMs), and switchgrass yields collected at 45 field trial locations as the response variable. The model incorporated variables previously shown to be the main determinants of switchgrass yield, and utilized current and predicted 1 km climate data from WorldClim. The models were run with current WorldClim data and compared with results of predicted yield obtained using two climate change scenarios across three global change models for three time steps. Results did not predict an increase in maximum switchgrass yield but showed an overall shift in areas of high switchgrass productivity for both cytotypes. For upland cytotypes, the shift in high yields was concentrated in northern and north-eastern areas where there were increases in average growing season temperature, whereas for lowland cultivars the areas where yields were projected to increase were associated with increases in average early growing season precipitation. These results highlight the fact that the influences of climate change on switchgrass yield are spatially heterogeneous and vary depending on cytotype. Knowledge of spatial distribution of suitable areas for switchgrass production under climate change should be incorporated into planning of current and future biofuel production. Understanding how switchgrass yields will be affected by future changes in climate is important for achieving a sustainable biofuels economy. (letter)

  13. Antimicrobial and anti-inflammatory activity of switchgrass-derived extractives

    Energy Technology Data Exchange (ETDEWEB)

    Labbe, Nicole; Ownley, Bonnie H.; Gwinn, Kimberly D.; Moustaid-Moussa, Naima; D' Souza, Doris H.

    2016-03-15

    Switchgrass is an increasingly important biofuel crop, but knowledge of switchgrass fungal pathogens is not extensive. The purpose of this research was to identify the fungal pathogens that decrease crop yield of switchgrass grown in Tennessee and to investigate a potential sustainable disease management strategy from a value-added by-product of the switchgrass biofuel conversion process. The specific objectives were 1) to identify and characterize prevalent fungal pathogens of switchgrass in Tennessee, 2) assess switchgrass seed produced in the United States for seedborne fungal pathogens, and 3) evaluate switchgrass extractives for antimicrobial activity against plant pathogens.

  14. Switchgrass growth and pine–switchgrass interactions in established intercropping systems

    Czech Academy of Sciences Publication Activity Database

    Tian, S.; Cacho, J. F.; Youssef, M. A.; Chescheir, G. M.; Fischer, Milan; Nettles, J. E.; King, J. S.

    2017-01-01

    Roč. 9, č. 5 (2017), s. 845-857 ISSN 1757-1693 Institutional support: RVO:67179843 Keywords : agroforestry * competition * grass growth * interspecific interactions * loblolly pine * switchgrass Subject RIV: GC - Agronomy OBOR OECD: Agronomy, plant breeding and plant protection Impact factor: 4.655, year: 2016

  15. Molecular markers linked to apomixis in Panicum maximum Jacq.

    African Journals Online (AJOL)

    SAM

    2014-05-28

    May 28, 2014 ... Panicum maximum Jacq. is an important forage grass of African origin largely used in the tropics. The genetic breeding of this ... Pastures play an important role in the national economy of most countries in the tropics .... final volume of 25 µL, using, 1xTaq DNA polymerase buffer. (Invitrogen); 1.5 mM MgCl2.

  16. Morfogênese de cultivares de Panicum maximum jacq. Morphogenesis of Panicum maximum jacq. cultivars

    Directory of Open Access Journals (Sweden)

    Carlos Augusto Miranda Gomide

    2000-04-01

    Full Text Available Quatro cultivares de Panicum maximum, Mombaça, Tanzânia, Vencedor e Centenário, foram cultivados em vasos, sob cobertura plástica transparente, para estudo da dinâmica do crescimento de folhas e perfilhos, em dois tipos de perfilho, o principal e o primário, e dois crescimentos, o de estabelecimento, logo após a emergência das plântulas, e o de rebrota, após corte, a 8 cm do solo, aos 21 dias. Os tratamentos foram estudados, em arranjo fatorial 4 x 2 x 2, segundo delineamento de blocos completamente casualizados com quatro repetições. O comprimento da lâmina foliar cresceu com o nível de inserção até a folha de número 9 ou 10, tornando-se menor nas folhas subseqüentes. O perfilhamento teve início na segunda semana de idade e se estendeu até 22 dias de idade, quando o número de perfilhos por planta se estabilizou. O cultivar Tanzânia apresentou maior número de perfilhos por planta (15, enquanto em Mombaça e Vencedor foram observados apenas 10 perfilhos. Maiores taxas de aparecimento e alongamento de folhas foram observadas durante o crescimento de estabelecimento. Em ambos os crescimentos, o cultivar Vencedor exibiu a maior taxa de aparecimento de folhas. O número médio de folhas verdes por perfilho estabilizou-se em 6,5 no cultivar Vencedor e 3,5 nos demais cultivares, no crescimento de rebrota, em que a vida útil das folhas foi de 29 dias para o cultivar Centenário e 36 dias para os demais.Four cultivars of Panicum maximum: Mombaça, Tanzânia, Centenário and Vencedor were grown in pots, under a transparent plastic cover, to evaluate the dynamic of leaf and tillers growth. Two growths, the establishment and the aftermath, after clipping at the age of 21 days, and two types of tiller, main and primary tillers, were studied. A completely randomized design with four replicates was used to compare the treatments resulting from a 4 x 2 x 2 factorial arrangement. The leaf blade length increased with insertion level until

  17. The distribution of 137Cs in maize (Zea mays L.) and two millet species (Panicum miliaceum L. and Panicum maximum Jacq.) cultivated on the cesium-contaminated soil

    International Nuclear Information System (INIS)

    Bystrzejewska-Nowacka, G.; Nowacka, R.

    2004-01-01

    The plant of three species (Zea mays L., Panicum miliaceum L. and Panicum maximum Jacq.) were grown on the soil contaminated with 0.3 mM CsCl solution traced with 137 Cs, in greenhouse. For all the species, the fresh-to-dry weight ratio was equal in the cesium-treated plants and in the central group after 3 weeks of culture. The shoot-to root fresh weight and dry weight ratios were decreased in maize, unchanged in Panicum miliaceum and increased in Panicum maximum, comparing to the control without cesium treatment. The shoot/soil and also root/soil transfer (TF) for 137 Cs (measured by means of Na I gamma spectrometer) were always the highest in maize, then lower in Panicum miliaceum and the lowest in Panicum maximum. All the plants seem to be hyperaccumulators of cesium. The root/soil Tf was especially high in maize, i.e. 55 (kBq kg -1 biomass)/kBq Kg -1 soil). The shoot/root concentration factor (CF) for 137 Cs was the lowest in maize, higher in Panicum miliaceum and highest in Panicum maximum. The proved ability of the investigated plants for phytoextraction of the soil cesium points to the (author). The detectability and reliin soil bioremediation. From this point of view, Panicum maximum seems to be the most useful plant because it accumulates cesium mainly in the shoot, and maize would be the least useful spices since it has the highest accumulation in root. (author)

  18. Responses of switchgrass to precipitation changes: Nonlinear and asymmetric?

    Science.gov (United States)

    Background/Question/Methods: Climate changes, including chronic changes in precipitation amounts, will influence plant physiology, biomass and productivity, and soil respiration. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. Two preci...

  19. Estimativas de repetibilidade para caracteres forrageiros em Panicum maximum Repeatability estimates for forage characters in Panicum maximum

    Directory of Open Access Journals (Sweden)

    Francisco José da Silva Lédo

    2008-08-01

    Full Text Available Objetiva-se com este trabalho estimar a repetibilidade para caracteres forrageiros de Panicum, e determinar o número de cortes de avaliação necessários para a seleção de genótipos de Panicum, com confiabilidade. Utilizaram-se os dados de um ensaio conduzido no período de 21/11/2002 a 08/04/2005, no Campo Experimental da Embrapa Gado de Leite, localizado em Valença-RJ, onde foram realizados 15 cortes de avaliação. No ensaio, foram avaliados 23 genótipos de Panicum maximum, em parcelas experimentais, dispostas no delineamento de blocos casualizados, com três repetições. Foram estimados os coeficientes de repetibilidade para as características produção de matéria verde de forragem (PMV; produção de matéria seca de forragem (PMS e de folhas (PMSF; porcentagem de folhas na PMS (%FOL e altura da planta (AP, utilizando os métodos da análise de variância, componentes principais e análise estrutural. Para todas as características avaliadas os efeitos de genótipos, cortes e interação genótipos x cortes foram significativos (PThe objective of this work was to estimate the repeatability for forage characters of Panicum and to determinate the necessary number of evaluation cuts to select Panicum genotypes with confidence. Data of a trial with 15 cuts, carried out between 21/11/2002 and 08/04/2005 in the experimental station of Embrapa Gado de Leite located in Valença, RJ, Brazil, were used. In this study. 23 genotypes of " Panicum maximum" were evaluated, in a complete randomized block, with three replications. The coefficient of repeatability for fresh forage production (PMV, total plant dry matter production (PMS and leaves dry matter production (PMSF were recorded along with leaves percentage in PMS (%FOL and plant hight (AP, using the variance analysis, main components and structural analysis methods. For all evaluated parameters the effects of genotype, cut and genotype x cut interaction were significant (P<0.01. When

  20. Compositional analysis of water-soluble materials in switchgrass.

    Science.gov (United States)

    Chen, Shou-Feng; Mowery, Richard A; Sevcik, Richard S; Scarlata, Christopher J; Chambliss, C Kevin

    2010-03-24

    Any valuation of a potential feedstock for bioprocessing is inherently dependent upon detailed knowledge of its chemical composition. Accepted analytical procedures for compositional analysis of biomass water-soluble extracts currently enable near-quantitative mass closure on a dry weight basis. Techniques developed in conjunction with a previous analytical assessment of corn stover have been applied to assess the composition of water-soluble materials in four representative switchgrass samples. To date, analytical characterization of water-soluble material in switchgrass has resulted in >78% mass closures for all four switchgrass samples, three of which have a mass closure of >85%. Over 30 previously unknown constituents in aqueous extracts of switchgrass were identified and quantified using a variety of chromatographic techniques. Carbohydrates (primarily sucrose, glucose, and fructose) were found to be the predominant water-soluble components of switchgrass, accounting for 18-27% of the dry weight of extractives. Total glycans (monomeric and oligomeric sugars) contributed 25-32% to the dry weight of extractives. Additional constituents contributing to the mass balance for extractives included various alditols (2-3%), organic acids (10-13%), inorganic ions (11-13%), and a distribution of oligomers presumed to represent a diverse mixture of lignin-carbohydrate complexes (30-35%). Switchgrass results are compared with previous analyses of corn stover extracts and presented in the context of their potential impact on biomass processing, feedstock storage, and future analyses of feedstock composition.

  1. Some Aspects Of The Autecology Of Panicum Turgidum Forsk

    OpenAIRE

    Ismail, A. M. A. [احمد محمد علي اسماعيل; El Seed, M. T.

    1983-01-01

    The germination of Panicum turgidum seeds was tested under different conditions. They showed ability to germinate under a range of temperatures from 25-42°C. The maximum percentage of germination was 45%, at 30°C. The species responded differently to the various chemical substances used to stimulate its germination. The particular effect of each chemical substance was discussed. The percentage of seedling emergence was highest in the case of seeds sown at 0. cm depth and decreased gradually a...

  2. Transport biofuel yields from food and lignocellulosic C{sub 4} crops

    Energy Technology Data Exchange (ETDEWEB)

    Reijnders, L. [IBED University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam (Netherlands)

    2010-01-15

    In the near future, the lignocellulosic C{sub 4} crops Miscanthus and switchgrass (Panicum virgatum) are unlikely to outcompete sugarcane (Saccharum officinarum) in net energetic yearly yield of transport biofuel ha{sup -1}. This holds both for the thermochemical conversion into liquid hydrocarbons and the enzymatic conversion into ethanol. Currently, Miscanthus and switchgrass would also not seem able to outcompete corn (Zea mays) in net energetic yearly yield of liquid transport biofuel ha{sup -1}, but further development of these lignocellulosic crops may gradually lead to a different outcome. (author)

  3. A Probabilistic Analysis of the Switchgrass Ethanol Cycle

    Directory of Open Access Journals (Sweden)

    Tadeusz W. Patzek

    2010-09-01

    Full Text Available The switchgrass-driven process for producing ethanol has received much popular attention. However, a realistic analysis of this process indicates three serious limitations: (a If switchgrass planted on 140 million hectares (the entire area of active U.S. cropland were used as feedstock and energy source for ethanol production, the net ethanol yield would replace on average about 20% of today’s gasoline consumption in the U.S. (b Because nonrenewable resources are required to produce ethanol from switchgrass, the incremental gas emissions would be on average 55 million tons of equivalent carbon dioxide per year to replace just 10% of U.S. automotive gasoline. (c In terms of delivering electrical or mechanical power, ethanol from 1 hectare (10,000 m2 of switchgrass is equivalent, on average, to 30 m2 of low-efficiency photovoltaic cells. This analysis suggests that investing toward more efficient and durable solar cells, and batteries, may be more promising than investing in a process to convert switchgrass to ethanol.

  4. Investigation of Pleurotus ostreatus pretreatment on switchgrass for ethanol production

    Science.gov (United States)

    Slavens, Shelyn Gehle

    Fungal pretreatment using the white-rot fungus Pleurotus ostreatus on switchgrass for ethanol production was studied. In a small-scale storage study, small switchgrass bales were inoculated with fungal spawn and automatically watered to maintain moisture. Sampled at 25, 53, and 81 d, the switchgrass composition was determined and liquid hot water (LHW) pretreatment was conducted. Fungal pretreatment significantly decreased the xylan and lignin content; glucan was not significantly affected by fungal loading. The glucan, xylan, and lignin contents significantly decreased with increased fungal pretreatment time. The effects of the fungal pretreatment were not highly evident after the LHW pretreatment, showing only changes based on sampling time. Although other biological activity within the bales increased cellulose degradation, the fungal pretreatment successfully reduced the switchgrass lignin and hemicellulose contents. In a laboratory-scale nutrient supplementation study, copper, manganese, glucose, or water was added to switchgrass to induce production of ligninolytic enzymes by P. ostreatus. After 40 d, ligninolytic enzyme activities and biomass composition were determined and simultaneous saccharification and fermentation (SSF) was conducted to determine ethanol yield. Laccase activity was similar for all supplements and manganese peroxidase (MnP) activity was significantly less in copper-treated samples than in the other fungal-inoculated samples. The fungal pretreatment reduced glucan, xylan, and lignin content, while increasing extractable sugars content. The lowest lignin contents occurred in the water-fungal treated samples and produced the greatest ethanol yields. The greatest lignin contents occurred in the copper-fungal treated samples and produced the lowest ethanol yields. Manganese-fungal and glucose-fungal treated samples had similar, intermediate lignin contents and produced similar, intermediate ethanol yields. Ethanol yields from switchgrass

  5. Controle químico de Panicum repens e Paspalum repens Chemical control of Panicum repens and Paspalum repens

    Directory of Open Access Journals (Sweden)

    C.A. Carbonari

    2004-09-01

    Full Text Available Panicum repens e Paspalum repens são espécies infestantes de ambientes úmidos e alagados, freqüentes em margens de lagos, reservatórios, canais de irrigação e drenagem. O presente trabalho teve como objetivo avaliar a eficiência de diferentes herbicidas no controle dessas duas espécies. O experimento foi conduzido no Núcleo de Pesquisas Avançadas em Matologia, do Departamento de Produção Vegetal, pertencente à Faculdade de Ciências Agronômicas/UNESP, campus de Botucatu-SP. As plantas foram cultivadas em caixas d'água e as pulverizações foram realizadas utilizando-se um pulverizador costal pressurizado a CO2. Os tratamentos testados foram: glyphosate a 2.400, 3.360 e 4.320 g e.a. ha-1 + Aterbane 0,5% v/v, glyphosate a 2.400, 3.360 e 4.320 g e.a. ha-1 + Silwet 0.1% v/v, imazapyr a 750 e 1.500 g e.a. ha-1 e diquat a 400 e 800 g i.a. ha-1 (em aplicações seqüenciais de 200+200 g i.a. ha-1 e 400+400 g i.a. ha-1, além de uma testemunha sem aplicação de herbicidas. O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições. Avaliações visuais de controle foram realizadas, sendo a massa seca das plantas determinada ao final do estudo. O herbicida glyphosate na dose de 4.320 g e.a. ha-1, independentemente do adjuvante utilizado, assim como na dose de 3.360 g e.a. ha-1 com Aterbane, proporcionou bom controle de Panicum repens e, em todas as doses e adjuvantes testados, promoveu controle excelente de Paspalum repens. O herbicida imazapyr, independentemente da dose testada, apresentou resultados insatisfatórios no controle das plantas de Panicum repens, porém promoveu um excelente controle de Paspalum repens; o herbicida diquat, apesar das duas aplicações e independentemente da dose utilizada, mostrou-se ineficiente para controle das duas espécies.Two experiments were carried out to evaluate the susceptibility of Panicum repens and Paspalum repens Bergius to different herbicides applied in

  6. Genotypic value in hybrid progenies of Panicum maximum Jacq.

    Directory of Open Access Journals (Sweden)

    Thiago Gomes dos Santos Braz

    Full Text Available ABSTRACT: Genetic breeding of forage plants has increasingly contributed to the release of more productive plants. In this regard, evaluating the genotypic value is essential when aiming to rank genotypes based on the mean free of environmental factors. Therefore, this study aimed to predict the genotypic value of agronomic and nutritive value characters of three progenies of Panicum maximum. Hybrids were evaluated in a clonal test in an incomplete-randomized design with three treatments (progenies 1, 2, and 3 and two replications (clones. Six harvests were performed at 25cm from the ground level throughout one year. Progeny 2 provided better results for total and leaf dry mass yield, regrowth, and height, and lower incidence of leaf spot. Progenies 1 and 3 had a better response for qualitative characters such as higher crude protein and digestibility and lower lignin and fiber content. Hybrid progenies of P. maximum have forage characters of interest for breeding, and when using ‘Mombaça’ grass as parents, the progeny stands out for leaf production and resistance to leaf spot and for ‘Tanzania’ grass as parent has resulted in better forage quality.

  7. Morphophysiological and chemical aspects of torpedograss (Panicum repens L., Poaceae

    Directory of Open Access Journals (Sweden)

    Simone Meredith Scheffer-Basso

    2007-09-01

    Full Text Available This work evaluated some of the morphophysiological and bromatological aspects of torpedograss (Panicum repens L. through the quantification of accumulation, allocation and chemical composition of dry matter (DM during spring-summer. Four destructive harvests of aerial and underground parts were carried out on 23 October 2003, 3 December 2003, 22 January 2004 and 20 February 2004, corresponding to 31, 73, 123 and 152 days after the start of the spring. In these harvests, the DM accumulation was respectively 1,650; 4,470; 10,900 and 14,540 kg/ha in the aerial part, with leaf percentages between 45% (first harvest and 35% (last harvest. The crude protein (CP, neutral detergent fiber (NDF and acid detergent fiber (ADF changed between the first and the last harvest, from 9.9 to 7% (CP, 63.9% to 70.3% (FDN, and 37% to 40.8% (FDA, in samples composed by leaves, culms, inflorescences and stolons. The DM allocation to rhizomes (Rh, roots (R, leaves (L, culms+stolons (C and inflorescences (I changed, between the first and the last harvest, from 42 to 19% (Rh, 10 to 7% (R, 22 to 27% (L, 25 to 44% (C, and 0 to 2% (I.

  8. Translational Genomics for the Improvement of Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Carpita, Nicholas; McCann, Maureen

    2014-05-07

    Our objectives were to apply bioinformatics and high throughput sequencing technologies to identify and classify the genes involved in cell wall formation in maize and switchgrass. Targets for genetic modification were to be identified and cell wall materials isolated and assayed for enhanced performance in bioprocessing. We annotated and assembled over 750 maize genes into gene families predicted to function in cell wall biogenesis. Comparative genomics of maize, rice, and Arabidopsis sequences revealed differences in gene family structure. In addition, differences in expression between gene family members of Arabidopsis, maize and rice underscored the need for a grass-specific genetic model for functional analyses. A forward screen of mature leaves of field-grown maize lines by near-infrared spectroscopy yielded several dozen lines with heritable spectroscopic phenotypes, several of which near-infrared (nir) mutants had altered carbohydrate-lignin compositions. Our contributions to the maize genome sequencing effort built on knowledge of copy number variation showing that uneven gene losses between duplicated regions were involved in returning an ancient allotetraploid to a genetically diploid state. For example, although about 25% of all duplicated genes remain genome-wide, all of the cellulose synthase (CesA) homologs were retained. We showed that guaiacyl and syringyl lignin in lignocellulosic cell-wall materials from stems demonstrate a two-fold natural variation in content across a population of maize Intermated B73 x Mo7 (IBM) recombinant inbred lines, a maize Association Panel of 282 inbreds and landraces, and three populations of the maize Nested Association Mapping (NAM) recombinant inbred lines grown in three years. We then defined quantitative trait loci (QTL) for stem lignin content measured using pyrolysis molecular-beam mass spectrometry, and glucose and xylose yield measured using an enzymatic hydrolysis assay. Among five multi-year QTL for lignin

  9. Biofuel, land and water: maize, switchgrass or Miscanthus?

    International Nuclear Information System (INIS)

    Zhuang Qianlai; Qin Zhangcai; Chen Min

    2013-01-01

    The productive cellulosic crops switchgrass and Miscanthus are considered as viable biofuel sources. To meet the 2022 national biofuel target mandate, actions must be taken, e.g., maize cultivation must be intensified and expanded, and other biofuel crops (switchgrass and Miscanthus) must be cultivated. This raises questions on the use efficiencies of land and water; to date, the demand on these resources to meet the national biofuel target has rarely been analyzed. Here, we present a data-model assimilation analysis, assuming that maize, switchgrass and Miscanthus will be grown on currently available croplands in the US. Model simulations suggest that maize can produce 3.0–5.4 kiloliters (kl) of ethanol for every hectare of land, depending on the feedstock to ethanol conversion efficiency; Miscanthus has more than twice the biofuel production capacity relative to maize, and switchgrass is the least productive of the three potential sources of ethanol. To meet the biofuel target, about 26.5 million hectares of land and over 90 km 3 of water (of evapotranspiration) are needed if maize grain alone is used. If Miscanthus was substituted for maize, the process would save half of the land and one third of the water. With more advanced biofuel conversion technology for Miscanthus, only nine million hectares of land and 45 km 3 of water would probably meet the national target. Miscanthus could be a good alternative biofuel crop to maize due to its significantly lower demand for land and water on a per unit of ethanol basis. (letter)

  10. Genetic diversity based on morphological data in Panicum maximum hybrids

    Directory of Open Access Journals (Sweden)

    Janaina Azevedo Martuscello

    2012-09-01

    Full Text Available The objective of this experiment was to evaluate the genetic divergence between hybrids obtained from 10 sexual genitors of the Panicum maximum breeding program at Embrapa Beef Cattle. For this, the following morphological descriptors were used: plant height, growth habit, leaf aspect, leaf waxiness, hair density on the sheath (DePB and blade (DePL, degree of hardiness of the hairs on the leaf sheath (DuPB and blade (DuPL and length of hairs on the sheath and blade. The characteristics growth habit and waxiness were not included in the analysis for being invariant. The phenotypic correlations were low and, therefore, not used to eliminate variables. By the principal component analysis, an 84.3% accumulation of the variation was observed until the fourth component. The last four principal components presented an estimate lower than 0.7 and allowed the identification of the variables DePB, DuPB and DuPL as the least important for diversity studies. The morphological characters used were not efficient to distinguish the progenies, but allowed the formation of morphological groups that converged with the graphic analysis of the principal components. An apparent error rate of 17.04% was observed in the classification of the individuals in the groups and 55.5% in the classification of the individuals in the progenies. The individuals in the P. maximum half-sib progenies are genetically divergent, but may not be grouped with only the descriptors used in this experiment. The pubescence characteristics were the least important in the discrimination of the genotypes.

  11. Panicum simulans (Paniceae, Poaceae, a new species from southern Africa and its leaf anatomy

    Directory of Open Access Journals (Sweden)

    L. Smook

    1993-10-01

    Full Text Available Panicum simulans Smook from northern Namibia is formally described. The morphology and leaf blade anatomy in transection and surface view, as observed under the light microscope, are described. The species is compared to others with which it has been confused in the past.  P. simulans can be readily distinguished from  P. novemnerve Stapf and P schinzii Hack, on the basis of both anatomical and morphological characters such as the venation of the lower glume and the photosynthetic anatomy, which is of the NAD-me subtype of the C4 photosynthetic pathway. On this basis it appears that P simulans is closely allied to the P. coloratum L. group of species and should be placed in section Panicum of subgenus Panicum.

  12. Análise de crescimento de cultivares de Panicum maximum Jacq. Growth analysis of Panicum maximum Jacq. cultivars

    Directory of Open Access Journals (Sweden)

    Carlos Augusto de Miranda Gomide

    1999-08-01

    Full Text Available O objetivo deste trabalho foi analisar o crescimento de três cultivares de Panicum maximum: Mombaça, Tanzânia e Vencedor cultivados em vasos, sob cobertura de lona plástica transparente. Os vasos foram cheios com 6 dm³ de latossolo vermelho-amarelo, textura argilosa, contendo alto teor de matéria orgânica. O solo, após ser peneirado, recebeu calagem e enriquecimento com N e P, 150 mg/dm³ de cada elemento. As sementes foram plantadas em vasos, num total de 54. Após desbaste, cinco plantas foram deixadas por vaso. Diariamente os vasos foram molhados e quinzenalmente fertilizados, cada um, com 50 mg/dm³ de N e K, em solução aquosa. Cada cultivar foi colhido às idades de 17, 24, 31, 38, 45 e 52 dias após emergência da semente. Houve três repetições para cada cultivar e idade. Em cada colheita, as plantas foram cortadas próximo à superfície do solo e separadas em folhas, colmo, raízes e material morto. A área das lâminas foliares foi medida em integrador de área foliar. Lâminas foliares, colmo e sistema radicular foram pesados após secagem a 60ºC por 72 horas. Valores instantâneos foram estimados para os índices de crescimento: área foliar específica (AFE, razão de peso foliar (RPF, razão de área foliar (RAF, taxa assimilatória líquida (TAL e taxa de crescimento relativo (TCR, de todos três cultivares. Houve diferenças entre os cultivares quanto aos valores instantâneos de RAF e TCR à idade de 17 dias. As variações de AFE foram as principais causas das mudanças em RAF. Nenhuma diferença foi observada entre os cultivares quanto à TAL.The objective of this work was to analyze the growth of three cultivars of Panicum maximum: Mombaça, Tanzânia and Vencedor grown in pots, under a transparent plastic cover. The pots were filled with 6 dm³ of redyellow latossol, clayish texture, with high organic matter content. The soil, after sifted, was limed and enriched with N and P, 150 mg/dm³ of each element. The

  13. Repetibilidade de caracteres agronômicos em Panicum maximum Jacq. Agronomic characters repeatability in Panicum maximum Jacq

    Directory of Open Access Journals (Sweden)

    Janaina Azevedo Martuscello

    2007-12-01

    Full Text Available O experimento foi conduzido para avaliar o coeficiente de repetibilidade de algumas características agronômicas em híbridos de Panicum maximum. Dez parcelas de plantas sexuais da espécie foram aleatoriamente distribuídas entre as 230 parcelas de acessos apomíticos. Após a fecundação natural, sementes de cada planta sexual constituíram-se uma família de meios-irmãos. Trinta plantas de cada progenitora foram avaliadas em delineamento de blocos ao acaso, com cinco plantas por parcela e seis repetições. A partir de cinco cortes, estimou-se o coeficiente de repetibilidade pelos métodos da Análise de Variância, Componentes principais (matriz de correlação e covariância e Análise estrutural. Os coeficientes de repetibilidade (r nos diferentes métodos, para todas as características avaliadas, oscilaram entre 0,51 e 0,86 e podem ser considerados altos, assim como os coeficientes de determinação. As estimativas do coeficiente de repetibilidade obtidas para as quatro características avaliadas pelo método da análise de variância foram quase sempre menores que as obtidas pelos demais métodos. Pelo método dos componentes principais (baseado na matriz de covariância, as estimativas foram sempre maiores em relação aos demais métodos. Considerando satisfatórios níveis de 80 ou 90% de confiabilidade para avaliação da superioridade relativa dos híbridos para todas as características avaliadas, as cinco medições realizadas são suficientes para escolha da melhor planta. A exclusão dos cortes 1 e 2 promove aumento nos coeficientes de repetibilidade e determinação.The experiment was carried out to evaluate the coefficient of repeatability of some agronomic characteristics in Panicum maximum hybrids. Ten plots of sexual plants of this species were randomly distributed among 230 plots of apomitic accessions. After natural hybridization, seeds of each sexual plant constituted a half-sib family. Thirty plants of each female

  14. Natural cellulose fibers from switchgrass with tensile properties similar to cotton and linen.

    Science.gov (United States)

    Reddy, Narendra; Yang, Yiqi

    2007-08-01

    We report the production and characteristics of natural cellulose fibers obtained from the leaves and stems of switchgrass. In this paper, the composition, structure and properties of fibers obtained from the leaves and stem of switchgrass have been studied in comparison to the common natural cellulose fibers, such as cotton, linen and kenaf. The leaves and stems of switchgrass have tensile properties intriguingly similar to that of linen and cotton, respectively. Fibers were obtained from the leaves and stems of switchgrass using a simple alkaline extraction and the structure and properties of the fibers were studied. Fibers obtained from switchgrass leaves have crystallinity of 51%, breaking tenacity of 5.5 g per denier (715 MPa) and breaking elongation of 2.2% whereas the corresponding values for fibers obtained from switchgrass stems are 46%, 2.7 g per denier and 6.8%, respectively. Switchgrass is a relatively easy to grow and high yield biomass crop that can be source to partially substitute the natural and synthetic fibers currently in use. We hope that this research will stimulate interests in using switchgrass as a novel fiber crop in addition to being promoted as a potential source for biofuels. (c) 2007 Wiley Periodicals, Inc.

  15. Leaf Dynamics of Panicum maximum under Future Climatic Changes.

    Science.gov (United States)

    Britto de Assis Prado, Carlos Henrique; Haik Guedes de Camargo-Bortolin, Lívia; Castro, Érique; Martinez, Carlos Alberto

    2016-01-01

    Panicum maximum Jacq. 'Mombaça' (C4) was grown in field conditions with sufficient water and nutrients to examine the effects of warming and elevated CO2 concentrations during the winter. Plants were exposed to either the ambient temperature and regular atmospheric CO2 (Control); elevated CO2 (600 ppm, eC); canopy warming (+2°C above regular canopy temperature, eT); or elevated CO2 and canopy warming (eC+eT). The temperatures and CO2 in the field were controlled by temperature free-air controlled enhancement (T-FACE) and mini free-air CO2 enrichment (miniFACE) facilities. The most green, expanding, and expanded leaves and the highest leaf appearance rate (LAR, leaves day(-1)) and leaf elongation rate (LER, cm day(-1)) were observed under eT. Leaf area and leaf biomass were higher in the eT and eC+eT treatments. The higher LER and LAR without significant differences in the number of senescent leaves could explain why tillers had higher foliage area and leaf biomass in the eT treatment. The eC treatment had the lowest LER and the fewest expanded and green leaves, similar to Control. The inhibitory effect of eC on foliage development in winter was indicated by the fewer green, expanded, and expanding leaves under eC+eT than eT. The stimulatory and inhibitory effects of the eT and eC treatments, respectively, on foliage raised and lowered, respectively, the foliar nitrogen concentration. The inhibition of foliage by eC was confirmed by the eC treatment having the lowest leaf/stem biomass ratio and by the change in leaf biomass-area relationships from linear or exponential growth to rectangular hyperbolic growth under eC. Besides, eC+eT had a synergist effect, speeding up leaf maturation. Therefore, with sufficient water and nutrients in winter, the inhibitory effect of elevated CO2 on foliage could be partially offset by elevated temperatures and relatively high P. maximum foliage production could be achieved under future climatic change.

  16. Characterization of Brachypodium distachyon as a nonhost model against switchgrass rust pathogen Puccinia emaculata.

    Science.gov (United States)

    Gill, Upinder S; Uppalapati, Srinivasa R; Nakashima, Jin; Mysore, Kirankumar S

    2015-05-08

    Switchgrass rust, caused by Puccinia emaculata, is an important disease of switchgrass, a potential biofuel crop in the United States. In severe cases, switchgrass rust has the potential to significantly affect biomass yield. In an effort to identify novel sources of resistance against switchgrass rust, we explored nonhost resistance against P. emaculata by characterizing its interactions with six monocot nonhost plant species. We also studied the genetic variations for resistance among Brachypodium inbred accessions and the involvement of various defense pathways in nonhost resistance of Brachypodium. We characterized P. emaculata interactions with six monocot nonhost species and identified Brachypodium distachyon (Bd21) as a suitable nonhost model to study switchgrass rust. Interestingly, screening of Brachypodium accessions identified natural variations in resistance to switchgrass rust. Brachypodium inbred accessions Bd3-1 and Bd30-1 were identified as most and least resistant to switchgrass rust, respectively, when compared to tested accessions. Transcript profiling of defense-related genes indicated that the genes which were induced in Bd21after P. emaculata inoculation also had higher basal transcript abundance in Bd3-1 when compared to Bd30-1 and Bd21 indicating their potential involvement in nonhost resistance against switchgrass rust. In the present study, we identified Brachypodium as a suitable nonhost model to study switchgrass rust which exhibit type I nonhost resistance. Variations in resistance response were also observed among tested Brachypodium accessions. Brachypodium nonhost resistance against P. emaculata may involve various defense pathways as indicated by transcript profiling of defense related genes. Overall, this study provides a new avenue to utilize novel sources of nonhost resistance in Brachypodium against switchgrass rust.

  17. An evaluation of Panicum maximum cv. Gatton: 1. The effect of ...

    African Journals Online (AJOL)

    Unknown

    The aim of this study was to evaluate the livestock production potential of Panicum maximum cv. Gatton ... consumed which varies according to the quantity and quality of forage on offer (Heitschmidt et al., 1990). The .... Dry matter availability differed between treatments both at the beginning and end of each grazing period.

  18. Economic and Environmental Assessment of Switchgrass Production on High-Fertility Soil and an Assessment of Anaerobic Digests as an Intermediate Market for Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Rhykerd, Robert [Illinois State Univ., Normal, IL (United States); Bierma, Thomas [Illinois State Univ., Normal, IL (United States); Jin, Guang [Illinois State Univ., Normal, IL (United States); Walker, Paul [Illinois State Univ., Normal, IL (United States)

    2014-03-31

    This project had two parts. Part 1 was an economic and environmental assessment of switchgrass production on high-fertility soil, and included an assessment of the effects of field irrigation with treated municipal wastewater (Studies A,C, and E in Final Agreement). Part 2 was an assessment of methods to enhance anaerobic digestion of switchgrass, and included evaluation of several other potential biomass feedstocks (Studies B and D in Final Agreement). Results from Part 1 demonstrated that switchgrass does not compete economically against a corn and soybean rotation on highly productive soils. All four varieties of switchgrass lost money while corn and soybeans were profitable in all four years of this study. Breakeven prices for the four switchgrass varieties were calculated using production costs. The installation of a center pivot irrigation system had minimal impact on crop production and corn and soybean production remained profitable in the year the irrigator was installed. Because of drought and delays in installing the wastewater treatment plant, the irrigation system was not used until year 4 of this study. Therefore, longer term studies evaluating multiple year studies on the impact of irrigation on switchgrass are warranted. Results from irrigating with treated municipal wastewater showed no negative impact on soil quality. Results from Part 2 demonstrated that anaerobic digestion (AD) of switchgrass could be significantly enhanced using low heat (100oC) and mild caustic pretreatment without fine-grinding. Heat for pretreatment could be available from biogas-based combined heat and power (CHP) systems. In bench-top digesters simulating municipal wastewater treatment AD, methane production of coarse-ground switchgrass increased over 20-fold with pretreatment compared to untreated switchgrass. Bench-top studies simulating dairy-based AD also found high specific methane yield, but even untreated switchgrass digested reasonably well, indicating the value of

  19. Compatibility of switchgrass as an energy crop in farming systems of the southeastern USA

    Energy Technology Data Exchange (ETDEWEB)

    Bransby, D.I.; Rodriguez-Kabana, R.; Sladden, S.E. [Auburn Univ., AL (United States)

    1993-12-31

    The objective of this paper is to examine the compatibility of switchgrass as an energy crop in farming systems in the southeastern USA, relative to other regions. In particular, the issues addressed are (1) competition between switchgrass as an energy crop and existing farm enterprises, based primarily on economic returns, (2) complementarity between switchgrass and existing farm enterprises, and (3) environmental benefits. Because projected economic returns for switchgrass as an energy crop are highest in the Southeast, and returns from forestry and beef pastures (the major existing enterprises) are low, there is a very strong economic incentive in this region. In contrast, based on current information, economic viability of switchgrass as an energy crop in other regions appears doubtful. In addition, switchgrass in the southeastern USA would complement forage-livestock production, row crop production and wildlife and would provide several additional environmental benefits. It is concluded that the southeastern USA offers the greatest opportunity for developing switchgrass as an economically viable energy crop.

  20. Genetic manipulation of lignin reduces recalcitrance and improves ethanol production from switchgrass

    Science.gov (United States)

    Fu, Chunxiang; Mielenz, Jonathan R.; Xiao, Xirong; Ge, Yaxin; Hamilton, Choo Y.; Rodriguez, Miguel; Chen, Fang; Foston, Marcus; Ragauskas, Arthur; Bouton, Joseph; Dixon, Richard A.; Wang, Zeng-Yu

    2011-01-01

    Switchgrass is a leading dedicated bioenergy feedstock in the United States because it is a native, high-yielding, perennial prairie grass with a broad cultivation range and low agronomic input requirements. Biomass conversion research has developed processes for production of ethanol and other biofuels, but they remain costly primarily because of the intrinsic recalcitrance of biomass. We show here that genetic modification of switchgrass can produce phenotypically normal plants that have reduced thermal-chemical (≤180 °C), enzymatic, and microbial recalcitrance. Down-regulation of the switchgrass caffeic acid O-methyltransferase gene decreases lignin content modestly, reduces the syringyl:guaiacyl lignin monomer ratio, improves forage quality, and, most importantly, increases the ethanol yield by up to 38% using conventional biomass fermentation processes. The down-regulated lines require less severe pretreatment and 300–400% lower cellulase dosages for equivalent product yields using simultaneous saccharification and fermentation with yeast. Furthermore, fermentation of diluted acid-pretreated transgenic switchgrass using Clostridium thermocellum with no added enzymes showed better product yields than obtained with unmodified switchgrass. Therefore, this apparent reduction in the recalcitrance of transgenic switchgrass has the potential to lower processing costs for biomass fermentation-derived fuels and chemicals significantly. Alternatively, such modified transgenic switchgrass lines should yield significantly more fermentation chemicals per hectare under identical process conditions. PMID:21321194

  1. Breeding and Selection of New Switchgrass Varieties for Increased Biomass Production

    Energy Technology Data Exchange (ETDEWEB)

    Taliaferro, C.M.

    2003-05-27

    Switchgrass breeding and genetics research was conducted from 1992-2002 at the Oklahoma State University as part of the national DOE-Bioenergy Feedstock Development Program (BFDP) effort to develop the species as a bioenergy feedstock crop. The fundamental objective of the program was to implement and conduct a breeding program to increase biomass yield capability in switchgrass and develop cultivars for the central and southern United States. Supporting research objectives included: (1) switchgrass germplasm collection, characterization, and enhancement; (2) elucidation of cytogenetic and breeding behavior; and (3) identification of best breeding procedures.

  2. Exploring Potential U.S. Switchgrass Production for Lignocellulosic Ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, Carla A [ORNL; Davis, Ethan [ORNL; Jager, Yetta [ORNL; West, Tristram O. [ORNL; Perlack, Robert D [ORNL; Brandt, Craig C [ORNL; Wullschleger, Stan D [ORNL; Baskaran, Latha Malar [ORNL; Webb, Erin [ORNL; Downing, Mark [ORNL

    2008-08-01

    In response to concerns about oil dependency and the contributions of fossil fuel use to climatic change, the U.S. Department of Energy has begun a research initiative to make 20% of motor fuels biofuel based in 10 years, and make 30% of fuels bio-based by 2030. Fundamental to this objective is developing an understanding of feedstock dynamics of crops suitable for cellulosic ethanol production. This report focuses on switchgrass, reviewing the existing literature from field trials across the United States, and compiling it for the first time into a single database. Data available from the literature included cultivar and crop management information, and location of the field trial. For each location we determined latitude and longitude, and used this information to add temperature and precipitation records from the nearest weather station. Within this broad database we were able to identify the major sources of variation in biomass yield, and to characterize yield as a function of some of the more influential factors, e.g., stand age, ecotype, precipitation and temperature in the year of harvest, site latitude, and fertilization regime. We then used a modeling approach, based chiefly on climatic factors and ecotype, to predict potential yields for a given temperature and weather pattern (based on 95th percentile response curves), assuming the choice of optimal cultivars and harvest schedules. For upland ecotype varieties, potential yields were as high as 18 to 20 Mg/ha, given ideal growing conditions, whereas yields in lowland ecotype varieties could reach 23 to 27 Mg/ha. The predictive equations were used to produce maps of potential yield across the continental United States, based on precipitation and temperature in the long term climate record, using the Parameter-elevation Regressions on Independent Slopes Model (PRISM) in a Geographic Information System (GIS). Potential yields calculated via this characterization were subsequently compared to the Oak Ridge

  3. Prospects for Hybrid Breeding in Bioenergy Grasses

    DEFF Research Database (Denmark)

    Aguirre, Andrea Arias; Studer, Bruno; Frei, Ursula

    2012-01-01

    , we address crucial topics to implement hybrid breeding, such as the availability and development of heterotic groups, as well as biological mechanisms for hybridization control such as self-incompatibility (SI) and male sterility (MS). Finally, we present potential hybrid breeding schemes based on SI...... of different hybrid breeding schemes to optimally exploit heterosis for biomass yield in perennial ryegrass (Lolium perenne L.) and switchgrass (Panicum virgatum), two perennial model grass species for bioenergy production. Starting with a careful evaluation of current population and synthetic breeding methods...

  4. Comprehensive Evaluation of Potassium-deficiency Stress of Switchgrass at Seedling Stage

    Directory of Open Access Journals (Sweden)

    ZHU Yi

    2014-04-01

    Full Text Available To illustrate the effects of potassium-deficiency stress on biomass, agronomic traits and physiological indexes of switchgrass, a sort of bioenergy crop, and to obtain the cultivar with best tolerance, 13 switchgrasses were treated under potassium-deficiency in hydroponic ar-tificial climatic chamber. The comprehensive evaluation was made through the analysis of evaluation indexes using standard deviation coeffi-cient allocation weighed method. The results indicated that: the potassium-deficiency stress had exerted significantly inhibitory effects on the aboveground and belowground growth of switchgrass, including the reduction of growth rate, decrease of chlorophyll content, reduction of ef-festive photosynthetic area, decrease of photosynthetic rate, which led to the lower biomass production. The tolerance of 13 switchgrasses from strong to weak was as follows: Cave-In-Rock, Trailblazer, BJ-5, Forestburg, BJ-4, Pathfinder, BJ-3, BJ-2, Blackwell, Alamo, BJ一1, BJ-6 and Kanlnw

  5. Diuretic activity of ethanolic extract of Panicum repens L. roots and rhizomes.

    Science.gov (United States)

    Hozaien, Hoda E; El-Tantawy, Walid Hamdy; Temraz, Abeer; El-Gindi, Omayma D; Taha, Kamilia F

    2018-02-08

    The diuretic activity of ethanolic extract of Panicum repens was investigated in rats. A single oral dose of 500 mg/kg of P. repens extract were given to rats, after 24 h, urine volume, its sodium and potassium concentrations were estimated. Treatment with P. repens extract caused a significant increase in tested parameters as compared to their corresponding controls, p < 0.05.

  6. Impact of Nitrogen Application Rate on Switchgrass Yield, Production Costs, and Nitrous Oxide Emissions.

    Science.gov (United States)

    McGowan, Andrew R; Min, Doo-Hong; Williams, Jeffery R; Rice, Charles W

    2018-03-01

    Switchgrass ( L.) has been promoted as a potential feedstock for cellulosic biofuel in the United States. Switchgrass is known to respond to N fertilizer, but optimal rates remain unclear. Given the potential nonlinear response of nitrous oxide (NO) emissions to N inputs, N additions to switchgrass above optimal levels could have large impacts on the greenhouse gas balance of switchgrass-based biofuel. Additionally, N additions are likely to have large impacts on switchgrass production costs. Yield, N removal, and net returns were measured in switchgrass receiving 0 to 200 kg N ha in Manhattan, KS, from 2012 to 2014. Emissions of NO were measured in the 0- to 150-kg N ha treatments. Total emissions of NO increased from 0.2 to 3.0 kg NO-N ha as N inputs increased from 0 to 150 kg N ha. The 3-yr averages of fertilizer-induced emission factors were 0.7, 2.1, and 2.6% at 50, 100, and 150 kg N ha, respectively. Removal of N at harvest increased linearly with increasing N rate. Switchgrass yields increased with N inputs up to 100 to 150 kg N ha, but the critical N level for maximum yields decreased each year, suggesting that N was being applied in excess at higher N rates. Net returns were maximized at 100 kg N ha at both a high and low urea cost (US$394.71 and $945.91 ha, respectively). These results demonstrate that N inputs were necessary to increase switchgrass productivity, but rates exceeding optimal levels resulted in excessive NO emissions and increased costs for producers. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  7. Morphological characters of Panicum maximum cv Gatton planted from different source of sapling

    Directory of Open Access Journals (Sweden)

    Fanindi A

    2014-03-01

    Full Text Available Morphological characters and agronomic information of Panicum maximum cv Gatton is required in forage crop breeding activities. Therefore a research was conducted to determine the morphology and characteristic of generative phase of Panicum maximum cv Gatton. The study was conducted in greenhouses, using a 40 cm diameter pot. The planting medium was soil from Ciawi (Latosol. Research design was Completely Randomized Design, with 10 replications. Treatments used were 2 types of planting material, 1 derived from the pols (vegetative and 2 seeds. Plants used were Panicum maximum cv Gatton that have been collected and evaluated at the IRIAP, Ciawi. Variables measured were plant morphology, reproductive traits, seed production per panicle and seed quality. Results showes that morphological characters of cv Gatton derived from seed and pols was not significantly different (p > 0.05, whereas the flowering time and the time of seeds mature after cutting derived from the seeds was faster (p < 0.05 than cultivars derived from pols. While the production of seed derived from the seeds was higher (p < 0.05 when compared to that derived from the pols.

  8. Effect of intercropping Panicum maximum var. Ntchisi and Lablab purpureus on the growth, herbage yield and chemical composition of Panicum maximum var. Ntchisi at different harvesting times.

    Science.gov (United States)

    Ojo, V O A; Dele, P A; Amole, T A; Anele, U Y; Adeoye, S A; Hassan, O A; Olanite, J A; Idowu, O J

    2013-11-15

    The study was conducted to evaluate the effect of intercropping Panicum maximum var. Ntchisi and Lablab purpureus on the growth, herbage yield and chemical composition of P. maximum var. Ntchisi at different harvesting times at the Teaching and Research farm, Federal University of Agriculture, Abeokuta in a randomized complete block design. Samples were collected at different harvesting times (8, 10, 12, 14 weeks after planting). The growth parameters which were plant height, leaf length, leaf number and tiller number measured showed that the intercropping of grass with legume were higher than in the sole plot of P. maximum var. Ntchisi. The plant yield was consistently higher (p < 0.05) in intercropped forages than in sole throughout the harvesting times. The crude protein contents of the forages were also higher for the intercropped across the treatments. The values of the fibre components were significantly different (p < 0.05) at different harvesting times and it was increasing as the harvesting time was increasing. From this study, considering the herbage yield and chemical composition of intecropping Panicum maximum var. Ntchisi and Lablab purpureus, they can be grazed by ruminant animals or harvested at 12 weeks after planting when the quality and quantity will support livestock productivity and can be conserved to be fed to ruminant animals during dry season when feed availability and quality are extremely low.

  9. Effet de Panicum maximum sur la productivité des femelles primipares durant le cycle de reproduction chez le cobaye (Cavia porcellus L.)

    OpenAIRE

    Danho, M.; Thys, E.; N'Goran D.V. Kouakou; Nogbou Assidjo, E.; Grongnet, JF.

    2012-01-01

    Effect of Panicum maximum on Productivity of Primiparous Females during Reproduction Cycle in Guinea Pigs (Cavia porcellus L.). In Ivory Coast, Guinea pigs reared for meat (Cavia porcellus L.) are mainly fed with Panicum maximum. To assess the effect of the latter during pregnancy and lactation (RC) of these animals, primiparous dams were fed ad libitum, Panicum maximum alone during the RC (MOD1) or associated with pellets for rabbits during lactation (MOD2), or associated with pellets for ra...

  10. Kinetics of methane production from the codigestion of switchgrass and Spirulina platensis algae.

    Science.gov (United States)

    El-Mashad, Hamed M

    2013-03-01

    Anaerobic batch digestion of four feedstocks was conducted at 35 and 50 °C: switchgrass; Spirulina platensis algae; and two mixtures of both switchgrass and S. platensis. Mixture 1 was composed of 87% switchgrass (based on volatile solids) and 13% S. platensis. Mixture 2 was composed of 67% switchgrass and 33% S. platensis. The kinetics of methane production from these feedstocks was studied using four first order models: exponential, Gompertz, Fitzhugh, and Cone. The methane yields after 40days of digestion at 35 °C were 355, 127, 143 and 198 ml/g VS, respectively for S. platensis, switchgrass, and Mixtures 1 and 2, while the yields at 50 °C were 358, 167, 198, and 236 ml/g VS, respectively. Based on Akaike's information criterion, the Cone model best described the experimental data. The Cone model was validated with experimental data collected from the digestion of a third mixture that was composed of 83% switchgrass and 17% S. platensis. Published by Elsevier Ltd.

  11. Rheology of transgenic switchgrass reveals practical aspects of biomass processing.

    Science.gov (United States)

    Wan, Guigui; Frazier, Taylor; Jorgensen, Julianne; Zhao, Bingyu; Frazier, Charles E

    2018-01-01

    Mechanical properties of transgenic switchgrass have practical implications for biorefinery technologies. Presented are fundamentals for simple (thermo)mechanical measurements of genetically transformed switchgrass. Experimental basics are provided for the novice, where the intention is to promote collaboration between plant biologists and materials scientists. Stem sections were subjected to two stress modes: (1) torsional oscillation in the linear response region, and (2) unidirectional torsion to failure. Specimens were analyzed while submerged/saturated in ethylene glycol, simulating natural hydration and allowing experimental temperatures above 100 °C for an improved view of the lignin glass transition. Down-regulation of the 4-Coumarate:coenzyme A ligase gene (reduced lignin content and altered monomer composition) generally resulted in less stiff and weaker stems. These observations were associated with a reduction in the temperature and activation energy of the lignin glass transition, but surprisingly with no difference in the breadth and intensity of the tan  δ signal. The results showed promise in further investigations of how rheological methods relate to stem lignin content, composition, and functional properties in the field and in bioprocessing. Measurements such as these are complicated by small specimen size; however, torsional rheometers (relatively common in polymer laboratories) are well suited for this task. As opposed to the expense and complication of relative humidity control, solvent-submersion rheological methods effectively reveal fundamental structure/property relationships in plant tissues. Demonstrated are low-strain linear methods, and also nonlinear yield and failure analysis; the latter is very uncommon for typical rheological equipment.

  12. Macronutrients leaf contents of corn in consortium with forage of the genus Panicum and Urochloa

    Directory of Open Access Journals (Sweden)

    Verena Micheletti Protes

    2013-12-01

    Full Text Available In recent years, the corn crop in Brazil has undergone major technological changes, aiming at a sustainable production. This improvement may be related to appropriate management, which includes, among other practices, crop rotation and tillage; that one can get through crop-livestock integration (CLI. The CLI can be done by the consortium sequence or crop rotation with annual forages in order to recover degraded pastures. This work aimed to evaluate the macronutrient leaf content of corn intercropped with forages of the genus Panicum and Urochloa. The experiment was conducted at the Farm for Teaching, Research and Extension, Faculty of Engineering - UNESP, Ilha Solteira in an Oxisol in Savannah conditions, being in no-tillage for 8 years (previous corn crop. In nitrogen fertilization was applying 100 kg ha-1 of N as urea. The experimental design was a randomized block with four replications and five treatments: Panicum maximum cv. Tanzania sown during the nitrogen fertilization (CTD of the corn; Panicum maximum cv. Mombaça sown during the nitrogen fertilization (CMD of the corn; Urochloa brizantha Xaraes sown during the occasion of nitrogen fertilization (CBD of the corn; Urochloa ruziziensis sown during the nitrogen fertilization (CRD of the corn, and corn without intercropping (CWI. The grasses seeds were mixed with fertilizer minutes before sowing and placed in fertilizer seeder compartment and the fertilizer were deposited in the soil at a depth of 0.03 m in the amount of 5 kg ha-1. It was observed that there was no significant difference between the single corn tillage and the corn in intercropping with different modalities of forages of genus Panicum and Urochloa to foliar contents of N, P, K, Ca and Mg, demonstrating that the consortium did not influence the absorption of nutrients by corn. In respect to S, the consortium CTD, was higher only when compared at CWI, however, did not differ significantly from the others (Table 1. The

  13. Policy incentives for switchgrass production using valuation of non-market ecosystem services

    International Nuclear Information System (INIS)

    Chamberlain, Jim F.; Miller, Shelie A.

    2012-01-01

    This study presents a linear profit model with combined economic and environmental factors for a switchgrass-for-biofuels agricultural system in the southeastern U.S. The objectives are to establish conversion-to-switchgrass thresholds for various market prices and identify policy incentives that would ensure economic profit while also maximizing environmental benefits (carbon sequestration, displacement of fossil fuels) and minimizing negative impacts (global warming potential, nitrate loss). Weighting factors are chosen to represent incentives and penalties by assigning value to the impacts. With no other incentives, switchgrass market prices of at least $51 and $58/dton would be needed in order to make a profitable switch from corn/Conservation Reserve Program (CRP) lands and cotton, respectively. At a mid-range offering of $50/dton, feasible carbon credit prices of $3/ $8/ $23 per metric tonne CO 2 e would incentivize conversion from corn, CRP, or cotton, respectively. Similarly, a water quality penalty of $0.20/ $3/ $2 per kilogram NO 3 –N leached would incentivize the same conversions with resultant watershed improvement. At a lower price of $30/dton switchgrass, incentives based on valuation of ecosystem services begin to exceed feasible ranges of these valuations. - Highlights: ► A linear effective profit model predicts conversion thresholds to switchgrass. ► Carbon and nitrogen fluxes can be valued and incorporated into producer choices. ► Farmgate prices alone of $51 and $58/dton switchgrass will entice conversion. ► Reasonable ecosystem service valuations will encourage adoption of switchgrass.

  14. Using satellite vegetation and compound topographic indices to map highly erodible cropland buffers for cellulosic biofuel crop developments in eastern Nebraska, USA

    Science.gov (United States)

    Gu, Yingxin; Wylie, Bruce K.

    2015-01-01

    Cultivating annual row crops in high topographic relief waterway buffers has negative environmental effects and can be environmentally unsustainable. Growing perennial grasses such as switchgrass (Panicum virgatum L.) for biomass (e.g., cellulosic biofuel feedstocks) instead of annual row crops in these high relief waterway buffers can improve local environmental conditions (e.g., reduce soil erosion and improve water quality through lower use of fertilizers and pesticides) and ecosystem services (e.g., minimize drought and flood impacts on production; improve wildlife habitat, plant vigor, and nitrogen retention due to post-senescence harvest for cellulosic biofuels; and serve as carbon sinks). The main objectives of this study are to: (1) identify cropland areas with high topographic relief (high runoff potentials) and high switchgrass productivity potential in eastern Nebraska that may be suitable for growing switchgrass, and (2) estimate the total switchgrass production gain from the potential biofuel areas. Results indicate that about 140,000 hectares of waterway buffers in eastern Nebraska are suitable for switchgrass development and the total annual estimated switchgrass biomass production for these suitable areas is approximately 1.2 million metric tons. The resulting map delineates high topographic relief croplands and provides useful information to land managers and biofuel plant investors to make optimal land use decisions regarding biofuel crop development and ecosystem service optimization in eastern Nebraska.

  15. Impact of harvesting time on ultimate methane yield of switchgrass grown in eastern Canada

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, Y.; Masse, D. [Agriculture and Agri-Food Canada, Sherbrooke, PQ (Canada). Dairy and Swine Research and Development Centre; Savoie, P.; Belanger, G.; Parent, G. [Agriculture and Agri-Food Canada, Quebec City, PQ (Canada). Soils and Crops Research and Development Centre; Babineau, D.L. [Groupe EBI, Berthierville, PQ (Canada)

    2010-07-01

    European research in green energy production from crops has resulted in the development of full scale bioreactors that use energy crops as feedstock. Switchgrass has been touted as one of the most promising crops for energy production among several perennial grass species grown under moderate to hot climates. However, few studies have been conducted in colder climate conditions. This study examined the mesophilic methane yield of switchgrass grown under the cooler growing conditions that exist in northeastern North America. In 2007, switchgrass was harvested in late July, August and September and conserved as silage. The regrowth of plots harvested in late July was also harvested in late September as a two-cut strategy. A 30 L small-scale laboratory digester was used to anaerobically digest the switchgrass silage samples. Specific methane yield decreased considerably with advancing plant development, but was similar between the first harvest in late July and the regrowth in late September. Nearly 25 per cent more methane could be produced by hectare for the two-cut strategy compared to harvesting once in late August. It was concluded that additional studies are needed to determine the effect of cutting times and strategies on the long term yield of switchgrass and to establish the production cost of this renewable energy.

  16. Efecto de la altura de poda en Leucaena leucocephala y su influencia en el rebrote y rendimiento de Panicum maximum

    OpenAIRE

    H. M. Bacab; F. J. Solorio; S. B. Solorio

    2012-01-01

    Una de las prácticas importantes de manejo en los sistemas de Leucaena leucocephala asociada con pastos tropicales, como Panicum maximum, es la poda; en la actualidad se continúan los estudios para determinar los efectos de esta práctica en el componente arbóreo y herbáceo. Por todo ello, en el presente trabajo se evaluó el efecto de tres alturas de poda en Leucaena leucocephala cv. Cunningham y su influencia en la pastura asociada (Panicum maximum cv. Tanzania). El estudio se realizó en la é...

  17. Investigating the impact of biomass quality on near-infrared models for switchgrass feedstocks

    Directory of Open Access Journals (Sweden)

    Lindsey M. Kline

    2015-12-01

    Full Text Available The aim of this study was to determine the impact of incorporating switchgrass samples that have been in long term storage on the development of near-infrared (NIR multivariate calibration models and their predictive capabilities. Stored material contains more variation in their respective spectral signatures due to chemical changes in the bales with storage time. Partial least squares (PLS regression models constructed using NIR spectra of stored switchgrass possessed an instability that interfered with the correlation between the spectral data and measured chemical composition. The models were improved using calibration sample sets of equal parts stored and fresh switchgrass to more accurately predict the chemical composition of stored switchgrass. Acceptable correlation values (rcalibration were obtained using a calibration sample set composed of 25 stored samples and 25 samples of fresh switchgrass for cellulose (0.91, hemicellulose (0.74, total carbohydrates (0.76, lignin (0.98, extractives (0.92, and ash (0.87. Increasing the calibration sample set to 100 samples of equal parts stored to senesced material resulted in statistically increased (p = 0.05 correlations for total carbohydrates (0.89 and ash (0.96. When these models were applied to a separate validation set (equal to 10% of the calibration sample set, high correlation coefficients (r for predicted versus measured constituent content were observed for cellulose (0.94, total carbohydrates (0.98, lignin (0.91, extractives (0.97, and ash (0.90. For optimization of processing economics, the impact of feedstock storage must be investigated for implementation in conversion processes. While NIR is a well-known high-throughput technique for characterization of senesced switchgrass, the selection of appropriate calibration samples and consequent multivariate models must be taken into careful consideration for NIR application in a biomass storage facility for rapid chemical compositional

  18. Analysis of environmental and economic tradeoffs in switchgrass supply chains for biofuel production

    International Nuclear Information System (INIS)

    Zhong, Jia; Yu, T. Edward; Larson, James A.; English, Burton C.; Fu, Joshua S.; Calcagno, James

    2016-01-01

    This study considered the environmental advantages of switchgrass, along with the economic challenges in its logistics, in the design of a sustainable switchgrass supply chain in Tennessee. Applying a multi-objective optimization model to high-resolution spatial data, potential tradeoffs among the objectives of minimizing feedstock costs, GHG (greenhouse gas) emissions, and soil erosion were identified for a set of conversion facilities on an efficient frontier. The tradeoff relationship was primarily driven by the type of agricultural land converted to switchgrass. Hay and pasture lands were more cost effective but resulted in higher soil carbon losses and soil erosion after being converted to switchgrass. Converting crop lands reduced GHG emissions and soil erosion but caused higher feedstock cost primarily due to the higher opportunity cost of land use. The respective average costs of abating GHG emissions and soil erosion on the efficient frontier were $2378 Mg −1 and $10 Mg −1 . The compromise solution conversion facility site generated 63% higher feedstock cost compared to the cost minimizing location, while reducing soil erosion by 70 fold and diminishing GHG emissions by 27%. Reducing soil erosion may be a more cost effective environmental criterion than reducing GHG emissions in developing a sustainable switchgrass supply chain in Tennessee. - Highlights: • Multi-objective optimization is applied to a switchgrass supply chain in Tennessee. • Tradeoffs are identified among costs, greenhouse gas, and soil erosion in supply chain. • The type of agricultural land converted to feedstock is a key factor to the tradeoffs. • Abating soil erosion rather than greenhouse gas is more cost effective in Tennessee.

  19. Effet de l'herbe de Guinée ( Panicum maximum Jacq.) associée à l ...

    African Journals Online (AJOL)

    Effet de l'herbe de Guinée ( Panicum maximum Jacq.) associée à l'herbe de lait ( Euphorbia heterophylla L.) ou aux feuilles de patate douce ( Ipomoea batatas (L.) Lam) sur la croissance des lapins ( Oryctolagus cuniculus L.)

  20. Macronutrients leaf contents of corn in intercropping with forages of genus Panicum and Urochloa in simultaneous seeding

    Directory of Open Access Journals (Sweden)

    Denise Tsuzukibashi

    2013-12-01

    Full Text Available The planting of crops in degraded pasture areas is a formula used for decades by farmers to recover the productive capacity of pastures and soils. The integrated crop-livestock (ICL consists of different production systems of grains, fibers, wood, meat, milk and agro-deployed in the same area, in intercrop, rotation or succession. Typically this integration mainly involves the planting of grain and pasture in the recovery or deployment. This work aimed to evaluate the macronutrients leaf contents of irrigated corn intercropped with forages of the genus Panicum and Urochloa simultaneously to sown corn. The experiment was conducted at the Farm for Teaching, Research and Extension, Faculty of Engineering - UNESP, Ilha Solteira in an Oxisol in Savannah conditions, in experimental area that had a history of no-tillage to 8 years (previous crop corn. The experimental design used was randomized blocks with four replications and five treatments: Panicum maximum cv. Tanzania sown simultaneously (CTS corn; Panicum maximum cv. Mombaça sown simultaneously (CMS to corn; Urochloa brizantha cv. Xaraes sown simultaneously (CBS corn; Urochloa ruziziensis sown simultaneously (CRS to corn, and corn without intercropping (CWI. The seeds of grasses were sown in spacing of 0.34 m, being sown with a seed drill with disc coulters mounted mechanism for no-tillage system at a depth of 0.03 m. There was no significant difference between the single corn tillage and intercropping with different modalities of forage genus Panicum and Urochloa to the leaf contents of N, P, K, Ca and Mg, demonstrating the non-compete forages with corn in a intercrop on the absorption of these nutrients. In respect to S, CTS presented higher content of S foliar when compared to CWI (Table 1. The absorption of nutrients by corn are not affect by the intercrop with forages of the genus Panicum and Urochloa, in simultaneously sown.

  1. Historical Perspective on How and Why Switchgrass was Seleced as a "Model" High-Potential Energy Crop

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Lynn [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2007-07-01

    Economic and environmental assessments by Oak Ridge National Laboratory’s Biofuels Feedstock Development Program staff together with the screening project results, and funding limitations lead to making the decision to further develop only switchgrass as a “model” or “prototype” species in about 1990. This paper describes the conditions under which the herbaceous species were screened, summarizes results from those trials, discusses the various factors which influenced the selection of switchgrass, and provides a brief evaluation of switchgrass with respect to criteria that should be considered when selecting and developing a crop for biofuels and bioproducts.

  2. Karyotype variation is indicative of subgenomic and ecotypic differentiation in switchgrass

    Science.gov (United States)

    A cytogenetic study was conducted on a dihaploid individual (2n'='2X'='18) of switchgrass to establish a chromosome karyotype. Size differences, condensation patterns, and arm-length ratios were used as identifying features and fluorescence in-situ hybridization (FISH) assigned 5S and 45S rDNA loci...

  3. RNA-seq analysis of overexpressing ovine AANAT gene of melatonin biosynthesis in switchgrass

    Directory of Open Access Journals (Sweden)

    Shan Yuan

    2016-08-01

    Full Text Available Melatonin serves important functions in the promotion of growth and anti-stress regulation by efficient radical scavenging and regulation of antioxidant enzyme activity in various plants. To investigate its regulatory roles and metabolism pathways, the transcriptomic profile of overexpressing the ovine arylalkylamine N-acetyltransferase (oAANAT gene, encoding the penultimate enzyme in melatonin biosynthesis, was compared with empty vector (EV control using RNA-seq in switchgrass, a model plant of cellulosic ethanol conversion. The 85.22 million high quality reads that were assembled into 135,684 unigenes were generated by Illumina sequencing for transgenic oAANAT switchgrass with an average sequence length of 716 bp. A total of 946 differential expression genes (DEGs in transgenic line comparing to control switchgrass, including 737 up-regulated and 209 down-regulated genes, were mainly enriched with two main functional patterns of melatonin identifying by gene ontology analysis: the growth regulator and stress tolerance. Furthermore, KEGG maps indicated that the biosynthetic pathways of secondary metabolite (phenylpropanoids, flavonoids, steroids, stilbenoid, diarylheptanoid and gingerol and signaling pathways (MAPK signaling pathway, estrogen signaling pathway were involved in melatonin metabolism. This study substantially expands the transcriptome information for switchgrass and provides valuable clues for identifying candidate genes involved in melatonin biosynthesis and elucidating the mechanism of melatonin metabolism.

  4. Characterization of biobased polyurethane foams employing lignin fractionated from microwave liquefied switchgrass

    Science.gov (United States)

    Xingyan Huang; Cornelis F. De Hoop; Jiulong Xie; Chung-Yun Hse; Jinqiu Qi; Tingxing Hu

    2017-01-01

    Lignin samples fractionated from microwave liquefied switchgrass were applied in the preparation of semirigid polyurethane (PU) foamswithout purification.Theobjective of this study was to elucidate the influence of lignin in thePUmatrix on themorphological, chemical,mechanical, and thermal properties of thePUfoams.Thescanning electron microscopy (SEM) images revealed...

  5. Sodium hydroxide pretreatment of genetically modified switchgrass for improved enzymatic release of sugars

    Science.gov (United States)

    Overcoming biomass recalcitrance to biological conversion has been the focus of enormous research efforts in the cellulosic biofuel area in the past decades. In this study, Alamo switchgrass was genetically transformed to suppress the expression of 4-coumarate-CoA ligase (4CL). The transgenic plants...

  6. Effects of precipitation changes on switchgrass photosynthesis, growth, and biomass: A mesocosm experiment

    Science.gov (United States)

    Climate changes, including chronic changes in precipitation amounts, will influence plant physiology and growth. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. We conducted a two-year precipitation simulation experiment using large pots...

  7. Low-heat, mild alkaline pretreatment of switchgrass for anaerobic digestion.

    Science.gov (United States)

    Jin, Guang; Bierma, Tom; Walker, Paul M

    2014-01-01

    This study examines the effectiveness of alkaline pretreatment under mild heat conditions (100°C or 212°F) on the anaerobic co-digestion of switchgrass. The effects of alkaline concentration, types of alkaline, heating time and rinsing were evaluated. In addition to batch studies, continuous-feed studies were performed in triplicate to identify potential digester operational problems caused by switchgrass co-digestion while accounting for uncertainty due to digester variability. Few studies have examined anaerobic digestion of switchgrass or the effects of mild heating to enhance alkaline pretreatment prior to biomass digestion. Results indicate that pretreatment can significantly enhance digestion of coarse-ground (≤ 0.78 cm particle size) switchgrass. Energy conversion efficiency as high as 63% was observed, and was comparable or superior to fine-grinding as a pretreatment method. The optimal NaOH concentration was found to be 5.5% (wt/wt alkaline/biomass) with a 91.7% moisture level. No evidence of operational problems such as solids build-up, poor mixing, or floating materials were observed. These results suggest the use of waste heat from a generator could reduce the concentration of alkaline required to adequately pretreat lignocellulosic feedstock prior to anaerobic digestion.

  8. Substrate-Specific Development of Thermophilic Bacterial Consortia by Using Chemically Pretreated Switchgrass

    OpenAIRE

    Eichorst, Stephanie A.; Joshua, Chijioke; Sathitsuksanoh, Noppadon; Singh, Seema; Simmons, Blake A.; Singer, Steven W.

    2014-01-01

    Microbial communities that deconstruct plant biomass have broad relevance in biofuel production and global carbon cycling. Biomass pretreatments reduce plant biomass recalcitrance for increased efficiency of enzymatic hydrolysis. We exploited these chemical pretreatments to study how thermophilic bacterial consortia adapt to deconstruct switchgrass (SG) biomass of various compositions. Microbial communities were adapted to untreated, ammonium fiber expansion (AFEX)-pretreated, and ionic-liqui...

  9. Comparison of Dilute Acid and Ionic Liquid Pretreatment of Switchgrass: Biomass Recalcitrance, Delignification and Enzymatic Saccharification

    Science.gov (United States)

    The efficiency of two biomass pretreatment technologies, dilute acid hydrolysis and dissolution in an ionic liquid, are compared in terms of delignification, saccharification efficiency and saccharide yields with switchgrass serving as a model bioenergy crop. When subject to ionic liquid pretreatme...

  10. Soil physical and hydrological properties under three biofuel crops in Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, Catherine [Ohio State University; Lal, Dr. Rattan [Ohio State University; Schmitz, Matthias [Rheinsche Friedrich/Wilhelms Universitaet Boon; Wullschleger, Stan D [ORNL

    2012-01-01

    While biofuel crops are widely studied and compared for their energy and carbon footprints, less is known about their effects on other soil properties, particularly hydrologic characteristics. Soils under three biofuel crops, corn (Zea mays), switchgrass (Panicum virgatum), and willow (Salix spp.), were analyzed seven years after establishment to assess the effects on soil bulk density ({rho}{sub b}), penetration resistance (PR), water-holding capacity, and infiltration characteristics. The PR was the highest under corn, along with the lowest associated water content, while PR was 50-60% lower under switchgrass. In accordance with PR data, surface (0-10 cm) bulk density also tended to be lower under switchgrass. Both water infiltration rates and cumulative infiltration amounts varied widely among and within the three crops. Because the Philip model did not fit the data, results were analyzed using the Kostiakov model instead. Switchgrass plots had an average cumulative infiltration of 69 cm over 3 hours with a constant infiltration rate of 0.28 cm min{sup -1}, compared with 37 cm and 0.11 cm min{sup -1} for corn, and 26 cm and 0.06 cm min{sup -1} for willow, respectively. Results suggest that significant changes in soil physical and hydrologic properties may require more time to develop. Soils under switchgrass may have lower surface bulk density, higher field water capacity, and a more rapid water infiltration rate than those under corn or willow.

  11. Soil physical and hydrological properties under three biofuel crops in Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, Catherine; Lal, Rattan [The Ohio State Univ., School of Environment and Natural Resources, Carbon Management and Sequestration Center, Columbus, OH (United States); Schmitz, Matthias [Rheinische Friedrich/Wilhelms-Universitaet Bonn, Steinmann Institut fuer Geologie, Mineralogie und Palaeontologie, Bonn (Germany); Wullschleger, S. [The Oakridge National Lab., Oakridge, TN (United States)

    2012-10-15

    While biofuel crops are widely studied and compared for their energy and carbon footprints, less is known about their effects on other soil properties, particularly hydrologic characteristics. Soils under three biofuel crops, corn (Zea mays), switchgrass (Panicum virgatum), and willow (Salix spp.), were analyzed seven years after establishment to assess the effects on soil bulk density ({rho}{sub b}), penetration resistance (PR), water-holding capacity, and infiltration characteristics. The PR was the highest under corn, along with the lowest associated water content, while PR was 50-60 % lower under switchgrass. In accordance with PR data, surface (0-10 cm) bulk density also tended to be lower under switchgrass. Both water infiltration rates and cumulative infiltration amounts varied widely among and within the three crops. Because the Philip model did not fit the data, results were analyzed using the Kostiakov model instead. Switchgrass plots had an average cumulative infiltration of 69 cm over 3 hours with a constant infiltration rate of 0.28 cm min{sup -1}, compared with 37 cm and 0.11 cm min{sup -1} for corn, and 26 cm and 0.06 cm min{sup -1} for willow, respectively. Results suggest that significant changes in soil physical and hydrologic properties may require more time to develop. Soils under switchgrass may have lower surface bulk density, higher field water capacity, and a more rapid water infiltration rate than those under corn or willow.

  12. Vaccinium virgatum fruit extract as an important adjuvant in biochemical and behavioral alterations observed in animal model of metabolic syndrome.

    Science.gov (United States)

    Oliveira, Pathise Souto; Gazal, Marta; Flores, Natália Porto; Zimmer, Aline Rigon; Chaves, Vitor Clasen; Reginatto, Flávio Henrique; Kaster, Manuella Pinto; Tavares, Rejane Giacomelli; Spanevello, Roselia Maria; Lencina, Claiton Leoneti; Stefanello, Francieli Moro

    2017-04-01

    The aim of this study was to investigate the effect of blueberry (Vaccinium virgatum) fruit extract on metabolic, behavioral and oxidative stress parameters in the hippocampus and cerebral cortex of mice submitted to an experimental model of metabolic syndrome induced by a highly palatable diet (HPD). Mice C57BL/6 were divided into 4 experimental groups: (1) received standard chow and saline orally, (2) received standard chow and blueberry hydroalcoholic extract, (3) received HPD and saline orally, (4) received HPD and blueberry hydroalcoholic extract. The animals were treated for 150days. Our results showed that the animals fed with HPD presented insulin resistance, increased body weight, visceral fat, glucose, triglycerides, and total cholesterol when compared to the control group. The blueberry extract prevented the increase of these metabolic parameters. Also, the extract was able to reduce the levels of thiobarbituric acid reactive substances in the cerebral cortex and hippocampus of animals submitted to HPD. In contrast, no differences were observed in the total thiol content, activity of the antioxidant enzymes catalase and superoxide dismutase. In addition, the HPD fed animals showed a significant increase in immobility time in the forced swimming test and blueberry prevented this alteration, although no changes were observed in the ambulatory behavior, as well as in the anxiolytic profile of these animals. Overall, our findings suggest that chronic consumption of blueberry extract exhibits hypoglycemic, hypolipidemic, antidepressant-like and antiperoxidative effects in an animal model of metabolic syndrome. Copyright © 2017. Published by Elsevier Masson SAS.

  13. Acumulación de hojarasca en un pastizal de Panicum maximum y en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala Litter accumulation in a Panicum maximum grassland and in a silvopastoral system of Panicum maximum and Leucaena leucocephala

    Directory of Open Access Journals (Sweden)

    Saray Sánchez

    2007-09-01

    Full Text Available Se realizó un estudio en la Estación Experimental de Pastos y Forrajes "Indio Hatuey", Matanzas, Cuba, con el objetivo de determinar la acumulación de la hojarasca en un pastizal de Panicum maximum Jacq cv. Likoni y en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala (Lam de Wit cv. Cunningham. En los pastizales de P. maximum de ambos sistemas se determinó la acumulación de la hojarasca según la técnica propuesta por Bruce y Ebershon (1982, mientras que la hojarasca de L. leucocephala acumulada en el sistema silvopastoril se determinó según Santa Regina et al. (1997. De forma general, los resultados demostraron que en ambos pastizales la guinea acumuló una menor cantidad de hojarasca durante el período junio-diciembre, etapa en la que se produce su mayor desarrollo vegetativo. En la leucaena la mayor producción de hojarasca ocurrió en el período de diciembre a enero, asociada con la caída natural de sus hojas que se produce por efecto de las temperaturas más bajas y la escasa humedad en el suelo. En el sistema silvopastoril la hojarasca de leucaena representó el mayor porcentaje de peso dentro de la producción total, con un contenido más alto de nitrógeno y de calcio que el de la hojarasca del estrato herbáceo. En la guinea la lluvia fue el factor climático que mayor correlación negativa presentó con la producción de hojarasca en ambos sistemas, y en la leucaena la mayor correlación negativa se encontró con la temperatura mínima.A study was carried out at the Experimental Station of Pastures and Forages "Indio Hatuey", Matanzas, Cuba, with the objective of determining the litter accumulation in a pastureland of Panicum maximum Jacq cv. Likoni and in a silvopastoral system of Panicum maximum and Leucaena leucocephala (Lam de Wit cv. Cunningham. In the P. maximum pasturelands of both systems the litter accumulation was determined by means of the technique proposed by Bruce and Ebershon (1982, while

  14. Antihepatotoxic Effect and Metabolite Profiling of Panicum turgidum Extract via UPLC-qTOF-MS

    Science.gov (United States)

    Farag, Mohamed A.; El Fishawy, Ahlam M.; El-Toumy, Sayed A.; Amer, Khadiga F.; Mansour, Ahmed M.; Taha, Hala E.

    2016-01-01

    Background: Panicum turgidum, desert grass, has not reported any detailed phytochemical or biological study as yet Objective: To establish P. turgidum secondary metabolite profile and to assess its antihepatotoxic effect Materials and Methods: Ultra-performance liquid chromatography (UPLC) coupled to quadrupole high-resolution time of flight mass spectrometry (qTOF-MS) was used for large-scale secondary metabolites profiling in P. turgidum extract, alongside assessing median lethal dose (LD50) and hepatoprotective effect against carbon tetrachloride (CCl4) intoxication Results: A total of 39 metabolites were identified with flavonoids as the major class present as O/C-glycosides of luteolin, apigenin, isorhamnetin and naringenin, most of which are first time to be reported in Panicum sp. Antihepatotoxic effect of P. turgidum crude extract was revealed via improving several biochemical marker levels and mitigation against oxidative stress in the serum and liver tissues, compared with CCl4 intoxicated group and further confirmed by histopathological examination. Conclusion: This study reveals that P. turgidum, enriched in C-flavonoids, presents a novel source of safe antihepatotoxic agents and further demonstrates the efficacy of UPLC-MS metabolomics in the field of natural products drug discovery. SUMMARY UPLC coupled to qTOF-MS was used for large scale secondary metabolites profiling in P. turgidum.A total of 39 metabolites were identified with flavonoids amounting as the major metabolite class.Anti-hepatotoxic effect of P. turgidum extract was revealed via several biochemical markers and histopathological examination.This study reveals that P. turgidum, enriched in C-flavonoids, present a novel source of antihepatotoxic agents. Abbreviations used: UPLC: Ultra-performance liquid chromatography (UPLC), LD50: median lethal dose, MDA: malondialdehyde, GSH: glutathione reductase, CAT: catalase, SOD: superoxide dismutase, ALT: alanine aminotransferase, AST: aspartate

  15. Proteomic responses of switchgrass and prairie cordgrass to senescence

    Directory of Open Access Journals (Sweden)

    Bimal ePaudel

    2016-03-01

    Full Text Available Senescence in biofuel grasses is a critical issue because early senescence decreases potential biomass production by limiting aerial growth and development. 2-Dimensional, differential in-gel electrophoresis (2D-DIGE followed by mass spectrometry of selected protein spots was used to evaluate differences between leaf proteomes of early (ES- and late- senescing (LS genotypes of Prairie cordgrass (ES/LS PCG and switchgrass (ES/LS SG, just before and after senescence was initiated. Analysis of the manually filtered and statistically evaluated data indicated that 69 proteins were significantly differentially abundant across all comparisons, and a majority (41 % were associated with photosynthetic processes as determined by gene ontology analysis. Ten proteins were found in common between PCG and SG, and nine and 18 proteins were unique to PCG and SG respectively. Five of the 10 differentially abundant spots common to both species were increased in abundance, and five were decreased in abundance. Leaf proteomes of the LS genotypes of both grasses analyzed before senescence contained significantly higher abundances of a 14-3-3 like protein and a glutathione-S-transferase protein when compared to the ES genotypes, suggesting differential cellular metabolism in the LS versus the ES genotypes. The higher abundance of 14-3-3 like proteins may be one factor that impacts the senescence process in both LS PCG and LS SG. Aconitase dehydratase was found in greater abundance in all four genotypes after the onset of senescence, consistent with literature reports from genetic and transcriptomic studies. A Rab protein of the Ras family of G proteins and an s-adenosylmethionine synthase were more abundant in ES PCG when compared with the LS PCG. In contrast, several proteins associated with photosynthesis and carbon assimilation were detected in greater abundance in LS PCG when compared to ES PCG, suggesting that a loss of these proteins potentially contributed to

  16. Fungic microflora of Panicum maximum and Styosanthes spp. commercial seed / Microflora fúngica de sementes comerciais de Panicum maximum e Stylosanthes spp.

    Directory of Open Access Journals (Sweden)

    Larissa Rodrigues Fabris

    2010-09-01

    Full Text Available The sanitary quality of 26 lots commercial seeds of tropical forages, produced in different regions (2004-05 and 2005-06 was analyzed. The lots were composed of seeds of Panicum maximum ('Massai', 'Mombaça' e 'Tanzânia' and stylo ('Estilosantes Campo Grande' - ECG. Additionally, seeds of two lots of P. maximum for exportation were analyzed. The blotter test was used, at 20ºC under alternating light and darkness in a 12 h photoperiod, for seven days. The Aspergillus, Cladosporium and Rhizopus genus consisted the secondary or saprophytes fungi (FSS with greatest frequency in P. maximum lots. In general, there was low incidence of these fungus in the seeds. In relation to pathogenic fungi (FP, it was detected high frequency of contaminated lots by Bipolaris, Curvularia, Fusarium and Phoma genus. Generally, there was high incidence of FP in P. maximum seeds. The occurrence of Phoma sp. was hight, because in 81% of the lots showed incidence superior to 50%. In 'ECG' seeds it was detected FSS (Aspergillus, Cladosporium, and Penicillium genus and FP (Bipolaris, Curvularia, Fusarium and Phoma genus, usually, in low incidence. FSS and FP were associated to P. maximum seeds for exportation, with significant incidence in some cases. The results indicated that there was a limiting factor in all producer regions regarding sanitary quality of the seeds.Sementes comerciais de forrageiras tropicais, pertencente a 26 lotes produzidos em diferentes regiões (safras 2004-05 e 2005-06, foram avaliadas quanto à sanidade. Foram analisadas sementes de cultivares de Panicum maximum (Massai, Mombaça e Tanzânia e de estilosantes (Estilosantes Campo Grande – ECG. Adicionalmente, avaliou-se a qualidade sanitária de dois lotes de sementes de P. maximum destinados à exportação. Para isso, as sementes foram submetidas ao teste de papel de filtro em gerbox, os quais foram incubados a 20ºC, com fotoperíodo de 12 h, durante sete dias. Os fungos saprófitos ou

  17. Sheep poisoning by Panicum dichotomiflorum in northeastern Brazil Intoxicação por Panicum dicotomiflorum em ovinos na região nordeste

    Directory of Open Access Journals (Sweden)

    Franklin Riet-Correa

    2009-01-01

    Full Text Available Different species of Panicum, including P. dichotomiflorum,have been reported as a cause of photosensitization in sheep, horses, cattle and goats. An outbreak of hepatogenous photosensitization occurred in 3 flocks of hair sheep in the Brazilian semiarid region. Eighty one out of 365 sheep were affected and 39 died. The main affected animals were nursing lambs and sheep younger than one year old. Donkeys, goats and cattle grazing in the same pasture were not affected. Clinical signs were edema of the head, followed by dermatitis, mainly in the face, ears, and croup, ocular discharge, corneal opacity with blindness, and redness of the coronary band and hoof. At necropsy of one affected lamb the liver was yellowish. Upon histologic examination scattered necrotic hepatocytes were observed in the liver and focal areas of necrosis of myocytes appeared in the heart. Samples of P. dicotomiflorum were analyzed by TLC and those containing saponins were isolated by HPLC using RP-C18 column and eluted with a mixture of MeOH and H2O. The isolated compounds were submitted to ¹H and 13C NMR spectroscopy. Reactions were positive to furostanol saponins with the same Rf of the standard protodioscin (0.21 and methylprotodioscin (0.32. The spectroscopic results indicated a mixture of (25R- and (25S-protodioscin isomers in a proportion of 3:1, and methylprotodioscin.Diferentes espécies de Panicum, incluindo P. dichotomiflorum,causam fotossensibilização em ovinos, eqüinos, bovinos e caprinos. Um surto de fotossensibilização hepatógena ocorreu em 3 rebanhos de ovinos no município de Casa Nova, Bahia. Oitenta e um de 365 ovinos adoeceram e 39 morreram. Cordeiros lactentes e ovinos de menos de um ano foram mais afetados. Jumentos, cabras e bovinos que permaneciam nas mesmas pastagens não foram afetados. Clinicamente observou-se edema da face, seguido por dermatite, principalmente da face, orelhas e garupa, corrimento ocular, opacidade da córnea com cegueira

  18. Consumo voluntário de forragem de três cultivares de Panicum maximum sob pastejo Voluntary intake of three cultivars of Panicum maximum under grazing

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    Valéria Pacheco Batista Euclides

    1999-01-01

    Full Text Available Os objetivos deste trabalho foram estimar o consumo de matéria seca de animais pastejando três cultivares de Panicum maximum e relacioná-lo com ganho de peso, tempo de pastejo (TP e algumas características químicas e estruturais do pasto. O delineamento experimental foi o de blocos casualizados com três tratamentos e três repetições. O consumo voluntário de matéria seca (CVMS foi estimado em quatro ocasiões (maio, setembro, novembro e fevereiro. Para calcular a produção de fezes, foi usado o óxido crômico como marcador externo. Foram estimados a digestibilidade in situ da matéria seca e o tempo de pastejo, respectivamente, por intermédio de extrusas e tacógrafos. Foram estimadas as disponibilidades da forragem e dos componentes da planta. Apesar de os CVMS pelos animais terem sido semelhantes entre as cultivares, foram observadas maiores diferenças nos ganhos de peso, para os animais pastejando o capim Tanzânia, seguidos daqueles pastejando os capins Colonião e Tobiatã. Diferenças também foram observadas entre as cultivares para TP, que foi menor para os animais em pasto de Tobiatã, quando comparados aos que pastejaram as outras duas cultivares. O aumento no TP observado durante o período da seca não foi suficiente para impedir queda no consumo de forragem neste período. O CVMS foi correlacionado (r² = 0,77 com ganho diário de peso. As características estruturais das pastagens, disponibilidade de folhas e relação material verde:material morto, influenciaram mais o CVMS, ganho de peso diário e TP que os valores nutritivos das mesmas.The objectives of this work were to estimate the dry matter intake by animals grazing three cultivars of Panicum maximum, and to relate it to live weight gain, grazing time (GT and some structural and chemical characteristics of the pastures. The experimental design was the randomized block with three treatments and three replicates. The dry matter voluntary intake (DMVI was

  19. New genomic resources for switchgrass: a BAC library and comparative analysis of homoeologous genomic regions harboring bioenergy traits

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    Feltus Frank A

    2011-07-01

    Full Text Available Abstract Background Switchgrass, a C4 species and a warm-season grass native to the prairies of North America, has been targeted for development into an herbaceous biomass fuel crop. Genetic improvement of switchgrass feedstock traits through marker-assisted breeding and biotechnology approaches calls for genomic tools development. Establishment of integrated physical and genetic maps for switchgrass will accelerate mapping of value added traits useful to breeding programs and to isolate important target genes using map based cloning. The reported polyploidy series in switchgrass ranges from diploid (2X = 18 to duodecaploid (12X = 108. Like in other large, repeat-rich plant genomes, this genomic complexity will hinder whole genome sequencing efforts. An extensive physical map providing enough information to resolve the homoeologous genomes would provide the necessary framework for accurate assembly of the switchgrass genome. Results A switchgrass BAC library constructed by partial digestion of nuclear DNA with EcoRI contains 147,456 clones covering the effective genome approximately 10 times based on a genome size of 3.2 Gigabases (~1.6 Gb effective. Restriction digestion and PFGE analysis of 234 randomly chosen BACs indicated that 95% of the clones contained inserts, ranging from 60 to 180 kb with an average of 120 kb. Comparative sequence analysis of two homoeologous genomic regions harboring orthologs of the rice OsBRI1 locus, a low-copy gene encoding a putative protein kinase and associated with biomass, revealed that orthologous clones from homoeologous chromosomes can be unambiguously distinguished from each other and correctly assembled to respective fingerprint contigs. Thus, the data obtained not only provide genomic resources for further analysis of switchgrass genome, but also improve efforts for an accurate genome sequencing strategy. Conclusions The construction of the first switchgrass BAC library and comparative analysis of

  20. Comparison of Chemical Composition and Energy Property of Torrefied Switchgrass and Corn Stover

    International Nuclear Information System (INIS)

    Tumuluru, Jaya Shankar

    2015-01-01

    In the present study, 6-mm ground corn stover and switchgrass were torrefied in temperatures ranging from 180 to 270°C for 15- to 120-min residence time. Thermogravimetric analyzer was used to do the torrefaction studies. At a torrefaction temperature of 270°C and a 30-min residence time, the weight loss increased to >45%. At 180°C and 120 min, there was about 56 and 73% of moisture loss in the corn stover and switchgrass; further increasing the temperature to 270°C and 120 min resulted in about 78.8–88.18% moisture loss in both the feedstock. Additionally, at these temperatures, there was a significant decrease in the volatile content and increase in the fixed carbon content, and the ash content for both the biomasses tested. The ultimate composition like carbon content increased and hydrogen content decreased with increase in the torrefaction temperature and time. At 270°C and 120-min residence time, the carbon content observed was 56.63 and 58.04% and hydrogen content observed was 2.74 and 3.14%. Nitrogen and sulfur content measured at 270°C and 120 min were 0.98, 0.8, 0.076, and 0.07% for both the corn stover and switchgrass. The hydrogen/carbon and oxygen/carbon ratios calculated decreased to the lowest values of 0.59 and 0.64, and 0.71 and 0.76 for both biomasses. The van Krevelen diagram drawn for corn stover and switchgrass torrefied at 270°C indicated that H/C and O/C values are closer to coals like Illinois Basis and Powder River Basin. In the present study, the maximum higher heating value that was observed by corn stover and switchgrass was 21.51 and 21.53 MJ/kg at 270°C and a 120-min residence time. From these results, it can be concluded that corn stover and switchgrass, after torrefaction, shows consistent proximate, ultimate, and energy properties.

  1. The effect of alcoholic extract of Panicum miliaceum L. seed on hippocampus neuronal density in male mouse

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    Arezoo Bornarodi

    2017-08-01

    Full Text Available Background: Hippocampus organization is a part of temporal lobe, which consists of several sections including hippocampal body, dentate gyrus and subiculum. Panicum miliaceum L. contains proteins, vitamins and antioxidants for human health. This study was conducted to examine the effect of the alcoholic extract of the seed of Panicum miliaceum L. plant on hippocampus neuronal density. Materials and Methods: In this experimental study, 24 male mice were divided into 4 groups (n=6, each group. The alcoholic extract of the seed of the Panicum miliaceum L. plant was prepared by soxhlet extraction. Three doses of the extract 25, 50, 75 mg/kg were intraperitoneally injected to 3 treatment groups for 21 days and the control group received normal saline injection. At the end of the experiment, the animals were anesthetized and after perfusion, their brains were removed from the skull. After tissue processing, slices of the brain were prepared and stained. Then, different regions of the hippocampus were photographed and neuronal densities were evaluated. Results: Results showed that the neuronal density in the CA1, CA3 regions of the group treated with 50 mg/kg of the alcoholic extract and in all regions of hippocampus (CA1,CA2,CA3 in groups treated with dose of 75 mg/kg of the alcoholic extract had a significant increase compared to the control group (P<0.05. Conclusion: The present study shows that the alcoholic extract of the seed of Panicum miliaceum L. plant increases neuronal density and induces neurogenesis in the mouse hippocampus.

  2. PRODUTIVIDADE E DEGRADABILIDADE RUMINAL DA FORRAGEM DE CAPINS da espécie Panicum maximum

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    Carlos Guilherme Silveira Pedreira

    2014-09-01

    Full Text Available O objetivo do presente estudo foi avaliar o acúmulo de forragem durante o verão agrostológico e a degradabilidade ruminal da matéria seca, fibra em detergente neutro e fibra em detergente ácido da forragem de cinco capins do gênero Panicum (Mombaça, Tanzânia, Massai, Tobiatã e Atlas em Piracicaba, SP. O período experimental foi de setembro de 2003 a março de 2004. Os intervalos de colheita foram fixados em períodos de 28 dias para Atlas, Massai e Mombaça e em períodos de 35 dias para Tanzânia e Tobiatã, em função de suas características morfológicas e estruturais. Amostras de forragem foram incubadas, adotando-se seis tempos de incubação: 96; 48; 24; 12; 6; 3 e 0 horas. Os cultivares Mombaça (15.500 kg MS ha-1 e Massai (20.400 kg MS ha-1 destacaram-se com as maiores produções de forragem. O estudo da degradabilidade in situ mostrou que, embora sua composição química seja bastante semelhante, alguns fatores importantes como a degradabilidade potencial, tempo de colonização e degradabilidade efetiva diferem entre genótipos, o que sugere diferentes potenciais de produção animal. Palavra-chave: gramínea, in situ, incubação, tempo de colonização.   FORAGE YIELD AND RUMINAL DEGRADABILITY OF FIVE Panicum spp GRASSES ABSTRACT The aim of this study was to evaluate the forage yield during the growing season of 2003/2004 as well as the ruminal dry matter degradability, neutral detergent fiber and acid detergent fiber concentration in the forage of five Panicum grasses (Mombaça, Tanzânia, Massai, Tobiatã and Atlas in Piracicaba, SP. Rest period was fixed on 28 days for Atlas, Massai and Mombaça and 35 days for Tanzânia and Tobiatã, according to their morphologic and structural characteristics. The samples were incubated for 96; 48; 24; 12; 6; 3 and 0 hours. Mombaça (15500 kg DM ha-1 and Massai (20400 kg DM ha-1 were the highest yielding genotypes. Ruminal degradability showed that, although chemical composition

  3. Agricultural Worker Injury Comparative Risk Assessment Methodology: Assessing Corn and Biofuel Switchgrass Production Systems.

    Science.gov (United States)

    Schwab, Charles V; Mosher, Gretchen A; Ryan, Saxon J

    2017-07-31

    Keeping workers safe is a continuing challenge in agricultural production. Risk assessment methodologies have been used widely in other industries to better understand systems and enhance decision making, yet their use in production agriculture has been limited. This article describes the considerations and the approach taken to measure the difference in worker injury risks between two agricultural production systems. A model was developed specifically for the comparison of worker injury risk between corn and biofuel switchgrass production systems. The model is composed of injury and exposure values that were used in a Monte Carlo simulation. The output of this risk assessment shows that approximately 99% of the values from the Monte Carlo simulation rank corn production as a greater worker injury risk than biofuel switchgrass production. Furthermore, the greatest contributing factors for each production system were identified as harvest, and that finding aligns with current literature. Copyright© by the American Society of Agricultural Engineers.

  4. Switchgrass storage effects on the recovery of carbohydrates after liquid hot water pretreatment and enzymatic hydrolysis

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    Danielle Julie Carrier

    2016-08-01

    Full Text Available Perennial grasses that would be used for bioenergy and bioproducts production will need to be stored for various periods of time to ensure a continual feedstock supply to a bioprocessing facility. The effects of storage practices on grass composition and the response of grasses to subsequent bioprocesses such as pretreatment and enzymatic hydrolysis needs to be understood to develop the most efficient storage protocols. This study examined the effect of outdoor storage of round switchgrass bales on composition before and after liquid hot water pretreatment (LHW and enzymatic hydrolysis. This study also examined the effect of washing LHW pretreated biomass prior to enzymatic hydrolysis. It was determined that switchgrass composition after baling was stable. As expected, glucan and lignin contents increased after LHW due to decreases in xylan and galactan. Washing biomass prior to enzymatic hydrolysis reduced saccharification, especially in samples from the interior of the bale, by at least 5%.

  5. Total number of tillers of different accessions of Panicum maximum Jacq.

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    Thiago Perez Granato

    2012-12-01

    Full Text Available The productivity of forage grasses is due to continuous emission of leaves and tillers, ensuring the restoration of leaf área after cutting or grazing, thus ensuring the sustainability of forage. This study aimed to asses the total number tillers in different acessions of Panicum maximum Jacq. The experiment was carried in field belonging to the Instituto de Zootecnia located in Nova Odessa / SP. Evaluated two new accesses Panicum maximum, and two commercial cultivars. The cultivars tested were Aruana, Milenio, NO 2487, NO 78, and the two latter belonging to the Germoplasm Collection of the IZ. The experimental desing was in randomized complete block with four replications. The experimental area consisted of 16 plots of 10 m2 (5 x 2 m each. The experimental area was analyzed and according to the results, received dolomitic limestone corresponding 2t /ha, two months before the implementation of the experiment. Sowing was made by broad costing together with 80 kg/ha of P2O5 in the form of single superphosfate. After 60 days of implantation of the experiment it was a made a leveling of the plots to a height of about 15 cm. After this it was applied 250g of the 20-00-20 fertilizer/plot. Thirty days after the standardization it was evaluated the total number of tillers of the cultivars, using a metal frame of 0.5 x 0.5m which was thrown at random on each of the 16 plots, leaving one meter of each extremitly, and all tillers which were within the frame counted. After finished the counting of all tillers, the plots cut again at a height of approximately 15 cm. The second evaluation took place after thirty days, and it was again counted the total number of tillers following the same procedure. The results were analyzed by Tukey test at 5% after transforming the data to log(x. For the first evaluation there was no statistical difference in the total number of tillers between cultivars. But, in the second evaluation, the total number of tillers of NO 78

  6. Association Mapping of Cell Wall Synthesis Regulatory Genes and Cell Wall Quality in Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Bartley, Laura [Univ. of Oklahoma, Norman, OK (United States). Dept. of Microbiology and Plant Biology; Wu, Y. [Oklahoma State Univ., Stillwater, OK (United States); Zhu, L. [Oklahoma State Univ., Stillwater, OK (United States); Brummer, E. C. [Noble Foundation, Ardmore, OK (United States); Saha, M. [Noble Foundation, Ardmore, OK (United States)

    2016-05-31

    Inefficient conversion of biomass to biofuels is one of the main barriers for biofuel production from such materials. Approximately half of polysaccharides in biomass remain unused by typical biochemical conversion methods. Conversion efficiency is influenced by the composition and structure of cell walls of biomass. Grasses such as wheat, maize, and rice, as well as dedicated perennial bioenergy crops, like switchgrass, make up ~55% of biomass that can be produced in the United States. Grass cell walls have a different composition and patterning compared with dicotyledonous plants, including the well-studied model plant, Arabidopsis. This project identified genetic determinants of cell wall composition in grasses using both naturally occurring genetic variation of switchgrass and gene network reconstruction and functional assays in rice. In addition, the project linked functional data in rice and other species to switchgrass improvement efforts through curation of the most abundant class of regulators in the switchgrass genome. Characterizing natural diversity of switchgrass for variation in cell wall composition and properties, also known as quality, provides an unbiased avenue for identifying biologically viable diversity in switchgrass cell walls. To characterizing natural diversity, this project generated cell wall composition and enzymatic deconstruction data for ~450 genotypes of the Switchgrass Southern Association Collection (SSAC), a diverse collection composed of 36 switchgrass accessions from the southern U.S. distribution of switchgrass. Comparing these data with other measures of cell wall quality for the same samples demonstrated the complementary nature of the diverse characterization platforms now being used for biomass characterization. Association of the composition data with ~3.2K single nucleotide variant markers identified six significant single nucleotide variant markers co-associated with digestibility and another compositional trait. These

  7. Switchgrass-Based Bioethanol Productivity and Potential Environmental Impact from Marginal Lands in China

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    Xun Zhang

    2017-02-01

    Full Text Available Switchgrass displays an excellent potential to serve as a non-food bioenergy feedstock for bioethanol production in China due to its high potential yield on marginal lands. However, few studies have been conducted on the spatial distribution of switchgrass-based bioethanol production potential in China. This study created a land surface process model (Environmental Policy Integrated Climate GIS (Geographic Information System-based (GEPIC model coupled with a life cycle analysis (LCA to explore the spatial distribution of potential bioethanol production and present a comprehensive analysis of energy efficiency and environmental impacts throughout its whole life cycle. It provides a new approach to study the bioethanol productivity and potential environmental impact from marginal lands based on the high spatial resolution GIS data, and this applies not only to China, but also to other regions and to other types of energy plant. The results indicate that approximately 59 million ha of marginal land in China are suitable for planting switchgrass, and 22 million tons of ethanol can be produced from this land. Additionally, a potential net energy gain (NEG of 1.75 x 106 million MJ will be achieved if all of the marginal land can be used in China, and Yunnan Province offers the most significant one that accounts for 35% of the total. Finally, this study obtained that the total environmental effect index of switchgrass-based bioethanol is the equivalent of a population of approximately 20,300, and a reduction in the global warming potential (GWP is the most significant environmental impact.

  8. Impact of an innovated storage technology on the quality of preprocessed switchgrass bales

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    Christopher N. Boyer

    2016-03-01

    Full Text Available The purpose of this study was to determine the effects of three particle sizes of feedstock and two types of novel bale wraps on the quality of switchgrass by monitoring the chemical changes in cellulose, hemicellulose, lignin, extractives, and ash over a 225-day period. Using NIR (Near-infrared modeling to predict the chemical composition of the treated biomass, differences were found in cellulose, lignin, and ash content across switchgrass bales with different particle sizes. Enclosing bales in a net and film impacted the cellulose, lignin, and ash content. Cellulose, hemicellulose, lignin, extractives, and ash were different across the 225-day storage period. A quadratic response function made better prediction about cellulose, lignin, and ash response to storage, and a linear response function best described hemicellulose and extractives response to storage. This study yields valuable information regarding the quality of switchgrass at different intervals between the start and end date of storage, which is important to conversion facilities when determining optimal storage strategies to improve quality of the biomass feedstock, based on potential output yield of a bale over time.

  9. Effects of precipitation changes on switchgrass photosynthesis, growth, and biomass: A mesocosm experiment.

    Science.gov (United States)

    Hui, Dafeng; Yu, Chih-Li; Deng, Qi; Dzantor, E Kudjo; Zhou, Suping; Dennis, Sam; Sauve, Roger; Johnson, Terrance L; Fay, Philip A; Shen, Weijun; Luo, Yiqi

    2018-01-01

    Climate changes, including chronic changes in precipitation amounts, will influence plant physiology and growth. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. We conducted a two-year precipitation simulation experiment using large pots (95 L) in an environmentally controlled greenhouse in Nashville, TN. Five precipitation treatments (ambient precipitation, and -50%, -33%, +33%, and +50% of ambient) were applied in a randomized complete block design with lowland "Alamo" switchgrass plants one year after they were established from tillers. The growing season progression of leaf physiology, tiller number, height, and aboveground biomass were determined each growing season. Precipitation treatments significantly affected leaf physiology, growth, and aboveground biomass. The photosynthetic rates in the wet (+50% and +33%) treatments were significantly enhanced by 15.9% and 8.1%, respectively, than the ambient treatment. Both leaf biomass and plant height were largely increased, resulting in dramatically increases in aboveground biomass by 56.5% and 49.6% in the +50% and +33% treatments, respectively. Compared to the ambient treatment, the drought (-33% and -50%) treatments did not influence leaf physiology, but the -50% treatment significantly reduced leaf biomass by 37.8%, plant height by 16.3%, and aboveground biomass by 38.9%. This study demonstrated that while switchgrass in general is a drought tolerant grass, severe drought significantly reduces Alamo's growth and biomass, and that high precipitation stimulates its photosynthesis and growth.

  10. Development of a Low Input and sustainable Switchgrass Feedstock Production System Utilizing Beneficial Bacterial Endophytes

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Chuansheng [IALR; Nowak, Jerzy [VPISU; Seiler, John [VPISU

    2014-10-24

    Switchgrass represents a promising feedstock crop for US energy sustainability. However, its broad utilization for bioenergy requires improvements of biomass yields and stress tolerance. In this DOE funded project, we have been working on harnessing beneficial bacterial endophytes to enhance switchgrass performance and to develop a low input feedstock production system for marginal lands that do not compete with the production of food crops. We have demonstrated that one of most promising plant growth-promoting bacterial endophytes, Burkholderia phytofirmans strain PsJN, is able to colonize roots and significantly promote growth of switchgrass cv. Alamo under in vitro, growth chamber, greenhouse, as well as field conditions. Furthermore, PsJN bacterization improved growth and development of switchgrass seedlings, significantly stimulated plant root and shoot growth, and tiller number in the field, and enhanced biomass accumulation on both poor (p<0.001) and rich (p<0.05) soils, with more effective stimulation of plant growth in low fertility soil. Plant physiology measurements showed that PsJN inoculated Alamo had consistently lower transpiration, lower stomatal conductance, and higher water use efficiency in greenhouse conditions. These physiological changes may significantly contribute to the recorded growth enhancement. PsJN inoculation rapidly results in an increase in photosynthetic rates which contributes to the advanced growth and development. Some evidence suggests that this initial growth advantage decreases with time when resources are not limited such as in greenhouse studies. Additionally, better drought resistance and drought hardening were observed in PsJN inoculated switchgrass. Using the DOE-funded switchgrass EST microarray, in a collaboration with the Genomics Core Facility at the Noble Foundation, we have determined gene expression profile changes in both responsive switchgrass cv. Alamo and non-responsive cv. Cave-in-Rock (CR) following Ps

  11. Biomass logistics analysis for large scale biofuel production: case study of loblolly pine and switchgrass.

    Science.gov (United States)

    Lu, Xiaoming; Withers, Mitch R; Seifkar, Navid; Field, Randall P; Barrett, Steven R H; Herzog, Howard J

    2015-05-01

    The objective of this study was to assess the costs, energy consumption and greenhouse gas (GHG) emissions throughout the biomass supply chain for large scale biofuel production. Two types of energy crop were considered, switchgrass and loblolly pine, as representative of herbaceous and woody biomass. A biomass logistics model has been developed to estimate the feedstock supply system from biomass production through transportation. Biomass in the form of woodchip, bale and pellet was investigated with road, railway and waterway transportation options. Our analysis indicated that the farm or forest gate cost is lowest for loblolly pine whole tree woodchip at $39.7/dry tonne and highest for switchgrass round bale at $72.3/dry tonne. Switchgrass farm gate GHG emissions is approximately 146kgCO2e/dry tonne, about 4 times higher than loblolly pine. The optimum biomass transportation mode and delivered form are determined by the tradeoff between fixed and variable costs for feedstock shipment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Community dynamics and glycoside hydrolase activities of thermophilic bacterial consortia adapted to switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Gladden, J.M.; Allgaier, M.; Miller, C.S.; Hazen, T.C.; VanderGheynst, J.S.; Hugenholtz, P.; Simmons, B.A.; Singer, S.W.

    2011-05-01

    Industrial-scale biofuel production requires robust enzymatic cocktails to produce fermentable sugars from lignocellulosic biomass. Thermophilic bacterial consortia are a potential source of cellulases and hemicellulases adapted to harsher reaction conditions than commercial fungal enzymes. Compost-derived microbial consortia were adapted to switchgrass at 60 C to develop thermophilic biomass-degrading consortia for detailed studies. Microbial community analysis using small-subunit rRNA gene amplicon pyrosequencing and short-read metagenomic sequencing demonstrated that thermophilic adaptation to switchgrass resulted in low-diversity bacterial consortia with a high abundance of bacteria related to thermophilic paenibacilli, Rhodothermus marinus, and Thermus thermophilus. At lower abundance, thermophilic Chloroflexi and an uncultivated lineage of the Gemmatimonadetes phylum were observed. Supernatants isolated from these consortia had high levels of xylanase and endoglucanase activities. Compared to commercial enzyme preparations, the endoglucanase enzymes had a higher thermotolerance and were more stable in the presence of 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), an ionic liquid used for biomass pretreatment. The supernatants were used to saccharify [C2mim][OAc]-pretreated switchgrass at elevated temperatures (up to 80 C), demonstrating that these consortia are an excellent source of enzymes for the development of enzymatic cocktails tailored to more extreme reaction conditions.

  13. Effects of precipitation changes on switchgrass photosynthesis, growth, and biomass: A mesocosm experiment.

    Directory of Open Access Journals (Sweden)

    Dafeng Hui

    Full Text Available Climate changes, including chronic changes in precipitation amounts, will influence plant physiology and growth. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. We conducted a two-year precipitation simulation experiment using large pots (95 L in an environmentally controlled greenhouse in Nashville, TN. Five precipitation treatments (ambient precipitation, and -50%, -33%, +33%, and +50% of ambient were applied in a randomized complete block design with lowland "Alamo" switchgrass plants one year after they were established from tillers. The growing season progression of leaf physiology, tiller number, height, and aboveground biomass were determined each growing season. Precipitation treatments significantly affected leaf physiology, growth, and aboveground biomass. The photosynthetic rates in the wet (+50% and +33% treatments were significantly enhanced by 15.9% and 8.1%, respectively, than the ambient treatment. Both leaf biomass and plant height were largely increased, resulting in dramatically increases in aboveground biomass by 56.5% and 49.6% in the +50% and +33% treatments, respectively. Compared to the ambient treatment, the drought (-33% and -50% treatments did not influence leaf physiology, but the -50% treatment significantly reduced leaf biomass by 37.8%, plant height by 16.3%, and aboveground biomass by 38.9%. This study demonstrated that while switchgrass in general is a drought tolerant grass, severe drought significantly reduces Alamo's growth and biomass, and that high precipitation stimulates its photosynthesis and growth.

  14. Towards the Development of a Molecular Map in Switchgrass: I. Microsatellite Marker Development; ANNUAL

    International Nuclear Information System (INIS)

    Gunter, L.E.

    2001-01-01

    The long-term goal of the switchgrass breeding program is to improve regionally adapted varieties and increase biomass yield and feedstock quality. Although, to some extent, biomass yields are dependent on environmental constraints, increased yield can be achieved through the development of genotypes with improved seasonal adaptation, tolerance to unfavorable environmental conditions, and improved resistance to pest and disease. To date, improvement in switchgrass has relied on recurrent breeding strategies based on phenotypic or genotypic selection. Yield improvements have been modest by this method. If we expect to make significant increase in yields, we need tools that will allow us to map complex traits and uncover the genes that influence them. A genetic linkage map could be a powerful tool for accelerating switchgrass development through marker-assisted selection, breeding and recombination. This type of mapping requires the development of markers that can be associated with phenotypic traits in a population of known pedigree. The most commonly used markers for mapping include restriction fragment length polymorphisms (RFLP) and simple sequence repeats (SSR). At ORNL, we have been concentrating on the development of SSR markers, while our colleagues at the University of Georgia are developing RFLP markers in order to select parents to produce a mapping population and from there to create a framework map from(approx)100 F1 progeny

  15. Comparative analysis of Panicum streak virus and Maize streak virus diversity, recombination patterns and phylogeography

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    Markham Peter G

    2009-11-01

    Full Text Available Abstract Background Panicum streak virus (PanSV; Family Geminiviridae; Genus Mastrevirus is a close relative of Maize streak virus (MSV, the most serious viral threat to maize production in Africa. PanSV and MSV have the same leafhopper vector species, largely overlapping natural host ranges and similar geographical distributions across Africa and its associated Indian Ocean Islands. Unlike MSV, however, PanSV has no known economic relevance. Results Here we report on 16 new PanSV full genome sequences sampled throughout Africa and use these together with others in public databases to reveal that PanSV and MSV populations in general share very similar patterns of genetic exchange and geographically structured diversity. A potentially important difference between the species, however, is that the movement of MSV strains throughout Africa is apparently less constrained than that of PanSV strains. Interestingly the MSV-A strain which causes maize streak disease is apparently the most mobile of all the PanSV and MSV strains investigated. Conclusion We therefore hypothesize that the generally increased mobility of MSV relative to other closely related species such as PanSV, may have been an important evolutionary step in the eventual emergence of MSV-A as a serious agricultural pathogen. The GenBank accession numbers for the sequences reported in this paper are GQ415386-GQ415401

  16. The genetics of divergence and reproductive isolation between ecotypes of Panicum hallii

    Science.gov (United States)

    Lowry, David B; Hernandez, Kyle; Taylor, Samuel H; Meyer, Eli; Logan, Tierney L; Barry, Kerrie W; Chapman, Jarrod A; Rokhsar, Daniel S; Schmutz, Jeremy; Juenger, Thomas E

    2015-01-01

    The process of plant speciation often involves the evolution of divergent ecotypes in response to differences in soil water availability between habitats. While the same set of traits is frequently associated with xeric/mesic ecotype divergence, it is unknown whether those traits evolve independently or if they evolve in tandem as a result of genetic colocalization either by pleiotropy or genetic linkage. The self-fertilizing C4 grass species Panicum hallii includes two major ecotypes found in xeric (var. hallii) or mesic (var. filipes) habitats. We constructed the first linkage map for P. hallii by genotyping a reduced representation genomic library of an F2 population derived from an intercross of var. hallii and filipes. We then evaluated the genetic architecture of divergence between these ecotypes through quantitative trait locus (QTL) mapping. Overall, we mapped QTLs for nine morphological traits that are involved in the divergence between the ecotypes. QTLs for five key ecotype-differentiating traits all colocalized to the same region of linkage group five. Leaf physiological traits were less divergent between ecotypes, but we still mapped five physiological QTLs. We also discovered a two-locus Dobzhansky–Muller hybrid incompatibility. Our study suggests that ecotype-differentiating traits may evolve in tandem as a result of genetic colocalization. PMID:25252269

  17. Transcriptomic analysis, genic SSR development, and genetic diversity of proso millet (Panicum miliaceum; Poaceae).

    Science.gov (United States)

    Hou, Siyu; Sun, Zhaoxia; Li, Yaoshen; Wang, Yijie; Ling, Hubin; Xing, Guofang; Han, Yuanhuai; Li, Hongying

    2017-07-01

    Proso millet ( Panicum miliaceum ; Poaceae) is a minor crop with good nutritional qualities and strong tolerance to drought stress and soil infertility. However, studies on genetic diversity have been limited due to a lack of efficient genetic markers. Illumina sequencing technology was used to generate short read sequences of proso millet, and de novo transcriptome assemblies were used to develop a de novo assembly of proso millet. Genic simple sequence repeat (SSR) markers were identified and used to detect polymorphism among 56 accessions. Population structure and genetic similarity coefficient were estimated. In total, 25,341 unique gene sequences and 4724 SSR loci were obtained from the transcriptome, of which 229 pairs of SSR primers were validated, which resulted in 14 polymorphic genic SSR primers exhibiting 43 total alleles. According to the ratio of polymorphic markers (6.1%, 14/229), there are potentially 288 polymorphic genic SSR markers available for genetic assay development in the future. Bayesian population analyses showed that the 56 accessions comprised two distinct groups. A genetic structure and cluster assay indicated that the accessions from the Loess Plateau of China shared a high genetic similarity coefficient with those from other regions and that there was no correlation between genetic diversity and geographic origin. The transcriptome sequencing data and millet-specific SSR markers developed in this study establish an excellent resource for gene discovery and may improve the development of breeding programs in proso millet in the future.

  18. Evaluation of ecophysiological characteristics of intercropping of millet (Panicum miliaceum L. and cowpea (Vigna unguiculata L.

    Directory of Open Access Journals (Sweden)

    A. Ghanbari

    2016-04-01

    Full Text Available In order to evaluate millet (Panicum miliaceum L. and cowpea (Vigna unguiculata L. intercropping, an experiment was conducted during 2008-2009 at Agriculture Research Center of Zabol University, Iran. The experiment was as randomized complete block design with three replications. Treatment s consisted of sole crop of millet, sole crop of cowpea, 25% millet + 100% cowpea, 50% millet + 50% cowpea, 75% millet + 100% cowpea and 100% millet + 100% cowpea. The results showed that intercropping treatments had significant effect (P < 1% on millet and bean seed yield, LER, dry matter of weeds, PAR, temperature and (P < 5% on soil moisture content. The highest seed yield of millet and cowpea obtained from treatments of sole crops. The LER for most intercrops was greater than one which indicated that intercropping had advantage over sole crop. For weeds management and control the results indicated that weed suppressing effects in intercropping treatments is better than sole crops treatment, so that the lowest dry matter of weeds obtained from 100% millet + 100% cowpea treatment. PAR in all of stages showed that the highest PAR interception obtained from intercropping treatments specially 100% millet + 100% cowpea treatment. In addition to the lowest of soil moisture content and temperature obtained from this treatment.

  19. Satellite panicum mosaic virus coat protein enhances the performance of plant virus gene vectors.

    Science.gov (United States)

    Everett, Anthany L; Scholthof, Herman B; Scholthof, Karen-Beth G

    2010-01-05

    The coat protein of satellite panicum mosaic virus (SPCP) is known to effectively protect its cognate RNA from deleterious events, and here, we tested its stabilizing potential for heterologous virus-based gene vectors in planta. In support of this, a Potato virus X (PVX) vector carrying the SPMV capsid protein (PVX-SPCP) gene was stable for at least three serial systemic passages through Nicotiana benthamiana. To test the effect of SPCP in trans, PVX-SPCP was co-inoculated onto N. benthamiana together with a Tomato bushy stunt virus (TBSV) vector carrying a green fluorescent protein (GFP) gene that normally does not support systemic GFP expression. In contrast, co-inoculation of TBSV-GFP plus PVX-SPCP resulted in GFP accumulation and concomitant green fluorescent spots in upper, non-inoculated leaves in a temperature-responsive manner. These results suggest that the multifaceted SPMV CP has intriguing effects on virus-host interactions that surface in heterologous systems.

  20. Effect of pollination mode on progeny of Panicum coloratum var. makarikariense: Implications for conservation and breeding

    Directory of Open Access Journals (Sweden)

    Lorena V. Armando

    2017-09-01

    Full Text Available Panicum coloratum var. makarikariense, a perennial grass native to Africa, is adapted to a wide range of soil and climatic conditions with potential to be used as forage in tropical and semi-arid regions around the world. Our objective was to understand how the pollination mode affects viable seed production and further survival of the progeny. We evaluated self- and open-pollinated progenies from different accessions by measuring the seed production of the parents and their germination performance, germination rate and seedling survival. Parents and progeny were also fingerprinted with Simple Sequence Repeats (SSR. Progeny produced through open-pollination resulted in significantly more filled seeds and superior seedling survival than self-pollination. These results indicate that accessions studied here rely heavily on cross-pollination, whereas the contribution of self-pollinated offspring to the population is likely to be low. SSR profiles showed that, on average, 85% of the progeny (arising from cross-pollination possessed paternal specific markers and 100% of them were genetically different from the maternal genotype. All plants examined had 4x = 36 chromosomes. Overall, our findings indicate that var. makarikariense is able to generate highly polymorphic progeny through segregation and recombination. This study provides reference information for the formulation of appropriate strategies for pasture germplasm management, conservation and development of breeding programs. 

  1. Extended light exposure increases stem digestibility and biomass production of switchgrass.

    Directory of Open Access Journals (Sweden)

    Chunqiao Zhao

    Full Text Available Switchgrass is a photoperiod-sensitive energy grass suitable for growing in the marginal lands of China. We explored the effects of extended photoperiods of low-irradiance light (7 μmol·m-2·s-1, no effective photosynthesis on the growth, the biomass dry weight, the biomass allocation, and, especially, the stem digestibility and cell wall characteristics of switchgrass. Two extended photoperiods (i.e., 18 and 24 h were applied over Alamo. Extended light exposure (18 and 24 h resulted in delayed heading and higher dry weights of vegetative organs (by 32.87 and 35.94%, respectively at the expense of reducing the amount of sexual organs (by 40.05 and 50.87%, respectively. Compared to the control group (i.e., natural photoperiod, the yield of hexoses (% dry matter in the stems after a direct enzymatic hydrolysis (DEH treatment significantly increased (by 44.02 and 46.10% for those groups irradiated during 18 and 24 h, respectively. Moreover, the yield of hexoses obtained via enzymatic hydrolysis increased after both basic (1% NaOH and acid (1% H2SO4 pretreatments for the groups irradiated during 18 and 24 h. Additionally, low-irradiance light extension (LILE significantly increased the content of non-structural carbohydrates (NSCs while notably reducing the lignin content and the syringyl to guaiacyl (S/G ratio. These structural changes were in part responsible for the observed improved stem digestibility. Remarkably, LILE significantly decreased the cellulose crystallinity index (CrI of switchgrass by significantly increasing both the arabinose substitution degree in xylan and the content of ammonium oxalate-extractable uronic acids, both favoring cellulose digestibility. Despite this LILE technology is not applied to the cultivation of switchgrass on a large scale yet, we believe that the present work is important in that it reveals important relationships between extended day length irradiations and biomass production and quality. Additionally

  2. Energy Potential and Greenhouse Gas Emissions from Bioenergy Cropping Systems on Marginally Productive Cropland

    Science.gov (United States)

    Schmer, Marty R.; Vogel, Kenneth P.; Varvel, Gary E.; Follett, Ronald F.; Mitchell, Robert B.; Jin, Virginia L.

    2014-01-01

    Low-carbon biofuel sources are being developed and evaluated in the United States and Europe to partially offset petroleum transport fuels. Current and potential biofuel production systems were evaluated from a long-term continuous no-tillage corn (Zea mays L.) and switchgrass (Panicum virgatum L.) field trial under differing harvest strategies and nitrogen (N) fertilizer intensities to determine overall environmental sustainability. Corn and switchgrass grown for bioenergy resulted in near-term net greenhouse gas (GHG) reductions of −29 to −396 grams of CO2 equivalent emissions per megajoule of ethanol per year as a result of direct soil carbon sequestration and from the adoption of integrated biofuel conversion pathways. Management practices in switchgrass and corn resulted in large variation in petroleum offset potential. Switchgrass, using best management practices produced 3919±117 liters of ethanol per hectare and had 74±2.2 gigajoules of petroleum offsets per hectare which was similar to intensified corn systems (grain and 50% residue harvest under optimal N rates). Co-locating and integrating cellulosic biorefineries with existing dry mill corn grain ethanol facilities improved net energy yields (GJ ha−1) of corn grain ethanol by >70%. A multi-feedstock, landscape approach coupled with an integrated biorefinery would be a viable option to meet growing renewable transportation fuel demands while improving the energy efficiency of first generation biofuels. PMID:24594783

  3. Energy potential and greenhouse gas emissions from bioenergy cropping systems on marginally productive cropland.

    Directory of Open Access Journals (Sweden)

    Marty R Schmer

    Full Text Available Low-carbon biofuel sources are being developed and evaluated in the United States and Europe to partially offset petroleum transport fuels. Current and potential biofuel production systems were evaluated from a long-term continuous no-tillage corn (Zea mays L. and switchgrass (Panicum virgatum L. field trial under differing harvest strategies and nitrogen (N fertilizer intensities to determine overall environmental sustainability. Corn and switchgrass grown for bioenergy resulted in near-term net greenhouse gas (GHG reductions of -29 to -396 grams of CO2 equivalent emissions per megajoule of ethanol per year as a result of direct soil carbon sequestration and from the adoption of integrated biofuel conversion pathways. Management practices in switchgrass and corn resulted in large variation in petroleum offset potential. Switchgrass, using best management practices produced 3919±117 liters of ethanol per hectare and had 74±2.2 gigajoules of petroleum offsets per hectare which was similar to intensified corn systems (grain and 50% residue harvest under optimal N rates. Co-locating and integrating cellulosic biorefineries with existing dry mill corn grain ethanol facilities improved net energy yields (GJ ha-1 of corn grain ethanol by >70%. A multi-feedstock, landscape approach coupled with an integrated biorefinery would be a viable option to meet growing renewable transportation fuel demands while improving the energy efficiency of first generation biofuels.

  4. De novo transcriptome assembly for the tropical grass Panicum maximum Jacq.

    Directory of Open Access Journals (Sweden)

    Guilherme Toledo-Silva

    Full Text Available Guinea grass (Panicum maximum Jacq. is a tropical African grass often used to feed beef cattle, which is an important economic activity in Brazil. Brazil is the leader in global meat exportation because of its exclusively pasture-raised bovine herds. Guinea grass also has potential uses in bioenergy production due to its elevated biomass generation through the C4 photosynthesis pathway. We generated approximately 13 Gb of data from Illumina sequencing of P. maximum leaves. Four different genotypes were sequenced, and the combined reads were assembled de novo into 38,192 unigenes and annotated; approximately 63% of the unigenes had homology to other proteins in the NCBI non-redundant protein database. Functional classification through COG (Clusters of Orthologous Groups, GO (Gene Ontology and KEGG (Kyoto Encyclopedia of Genes and Genomes analyses showed that the unigenes from Guinea grass leaves are involved in a wide range of biological processes and metabolic pathways, including C4 photosynthesis and lignocellulose generation, which are important for cattle grazing and bioenergy production. The most abundant transcripts were involved in carbon fixation, photosynthesis, RNA translation and heavy metal cellular homeostasis. Finally, we identified a number of potential molecular markers, including 5,035 microsatellites (SSRs and 346,456 single nucleotide polymorphisms (SNPs. To the best of our knowledge, this is the first study to characterize the complete leaf transcriptome of P. maximum using high-throughput sequencing. The biological information provided here will aid in gene expression studies and marker-assisted selection-based breeding research in tropical grasses.

  5. Selection of full-sib families of Panicum maximum Jacq under low light conditions

    Directory of Open Access Journals (Sweden)

    Douglas Mochi Victor

    2015-04-01

    Full Text Available The silvopastoral system is a viable technological alternative to extensive cattle grazing, however, for it to be successful, forage grass genotypes adapted to reduced light need to be identified. The objective of this study was to select progenies of Panicum maximum tolerant to low light conditions for use in breeding programs and to study the genetic control and performance of some traits associated with shade tolerance. Six full-sib progenies were evaluated in full sun, 50% and 70% of light reduction in pots and subjected to cuttings. Progeny genotypic values ​​(GV increased with light reduction in relation to plant height (H and specific leaf area (SLA. The traits total dry mass accumulation (DM and leaf dry mass accumulation (LDM had GV higher in 50% shade and intermediate in 70% shade. The GV of tiller number (TIL and root dry mass accumulation (RDM decreased with light reduction. The highest positive correlations were obtained for the traits H and RDM with SLA and DM; the highest negative correlations were between TIL and SLA and RDM, and H and LDM. The progenies showed higher tolerance to 50% light reduction and, among them, two stood out and will be used in breeding programs. It was also found that it is not necessary to evaluate some traits under all light conditions. All traits had high broad sense heritability and high genotypic correlation between progenies in all light intensities. There is genetic difference among the progenies regarding the response to different light intensities, which will allow selection for shade tolerance

  6. The Mechanisms of Salinity Tolerance in the Xero-halophyte Blue Panicgrass (Panicum antidotale Retz

    Directory of Open Access Journals (Sweden)

    Hamid R. ESHGHIZADEH

    2012-05-01

    Full Text Available Identifying the physiological traits associated with salt tolerance is important in optimal management of biosaline systems and optimum utilization of saline water resources in dry and saline areas. Therefore, some indices of photosynthetic activity, dry matter production and accumulation of sodium and potassium ions in Blue panicgrass (Panicum antidotale Retz were evaluated in five levels of salinity treatment (0, 70, 140, 210 and 280 mM NaCl solution under greenhouse conditions. The results showed that at 28 and 35 days after salt stress, plant leaf area reduced in the highest salinity treatment, 93 and 96% respectively, compared with control. Leaf stomatal conductance, CO2 fixation and quantum efficiency of photosystem II were decreased by increasing salinity. It caused also a reduction in chlorophyll content (Chl a, Chl b in leaves of Blue panicgrass. Content of carotenoids showed binary patterns to different salinity levels, slightly increased in 70-140 mM NaCl and decreased again in 210-280 mM, respectively. Increasing levels of salinity, increased sodium content in both roots and shoots but the shoots potassium content decreased. Decline in photosynthesis indices caused the reduction of root and shoot dry weight. This decrease resulted from lower leaf area (r=0.91**, lower stomatal conductance (r=0.78**, lower CO2 fixed in photosynthesis (r=0.63**, lower quantum efficiency of photosystem II (r=0.54** and lower Chl a (r=0.45**, respectively. Data analysis base on using stepwise regression introduced leaf area (?=0.560, chlorophyll a content (?=0.245 and shoot potassium content (?= 0.264 as main effective components of salinity tolerance in Blue panicgrass.

  7. Efecto de la altura de poda en Leucaena leucocephala y su influencia en el rebrote y rendimiento de Panicum maximum

    Directory of Open Access Journals (Sweden)

    H. M. Bacab

    2012-01-01

    Full Text Available Una de las prácticas importantes de manejo en los sistemas de Leucaena leucocephala asociada con pastos tropicales, como Panicum maximum, es la poda; en la actualidad se continúan los estudios para determinar los efectos de esta práctica en el componente arbóreo y herbáceo. Por todo ello, en el presente trabajo se evaluó el efecto de tres alturas de poda en Leucaena leucocephala cv. Cunningham y su influencia en la pastura asociada (Panicum maximum cv. Tanzania. El estudio se realizó en la época poco lluviosa del año (marzo a mayo de 2010, se utilizó un diseño de bloques completos al azar con cuatro repeticiones. Al inicio del experimento se asignaron los tratamientos (alturas de poda de 20, 40 y 60 cm sobre el nivel del suelo para Leucaena leucocephala. En el caso de Panicum maximum, se realizó una poda a 5 cm sobre el nivel del suelo en todas las parcelas experimentales. Los resultados obtenidos indicaron que la poda de la leguminosa a 40 y 60 cm permitió obtener brotes de mayor talla, sin afectar a la gramínea asociada. De igual manera, al incrementar la altura de poda, la leguminosa presentó mayor rendimiento y proporción de forraje comestible; sin embargo, se afectó negativamente a la pastura asociada. Ante ello, considerándose el aspecto animal, se recomienda no reducir la altura de poda de Leucaena leucocephala a menos de 40 cm, ya que se reduce significativamente el rendimiento y la proporción de forraje comestible de esta leguminosa, el cual es de mayor calidad para la alimentación animal.

  8. Historical Perspective on How and Why Switchgrass was Selected as a "Model" High-Potential Energy Crop

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Lynn L [ORNL

    2007-11-01

    A review of several publications of the Biofuels Feedstock Development Program, and final reports from the herbaceous crop screening trials suggests that there were several technical and non-technical factors that influenced the decision to focus on one herbaceous "model" crop species. The screening trials funded by the U.S. Department of Energy in the late 1980's to early 1990's assessed a wide range of about 34 species with trials being conducted on a wide range of soil types in 31 different sites spread over seven states in crop producing regions of the U.S. While several species, including sorghums, reed canarygrass and other crops, were identified as having merit for further development, the majority of institutions involved in the herbaceous species screening studies identified switchgrass as having high priority for further development. Six of the seven institutions included switchgrass among the species recommended for further development in their region and all institutions recommended that perennial grasses be given high research priority. Reasons for the selection of switchgrass included the demonstration of relatively high, reliable productivity across a wide geographical range, suitability for marginal quality land, low water and nutrient requirements, and positive environmental attributes. Economic and environmental assessments by Oak Ridge National Laboratory's Biofuels Feedstock Development Program staff together with the screening project results, and funding limitations lead to making the decision to further develop only switchgrass as a "model" or "prototype" species in about 1990. This paper describes the conditions under which the herbaceous species were screened, summarizes results from those trials, discusses the various factors which influenced the selection of switchgrass, and provides a brief evaluation of switchgrass with respect to criteria that should be considered when selecting and developing a crop for biofuels and

  9. CINÉTICA DE DEGRADABILIDAD in vitro DE CUATRO VARIEDADES DE Panicum maximum COSECHADAS A CUATRO EDADES

    OpenAIRE

    Juan Humberto Avellaneda Cevallos; Carlos Alberto Molina Hidrovo; Wilson Roberto Briones Caicedo; Máximo Fernando Tubay Moreira; Santiago Coello Díaz

    2015-01-01

    Se evaluó la degradabilidad in vitro de la materia seca (MS) de las hojas, tallos y planta completa de cuatro variedades de pasto Guinea (Panicum maximum: Común, Tanzania, Enano y Tobiata) en cuatro edades de cosecha (21, 42, 63 y 84 d). Se evaluó la composición química de las variedades. Para la digestibilidad in vitro, se empleó la primera fase de la técnica de Tilley y Terry, para lo cual se extrajo líquido ruminal de dos bovinos Brown Swiss canulados a rumen. Se evaluaron seis periodos de...

  10. The influence of phosphorus nutritional status on the uptake of germanium in Panicum miliaceum and Brassica alba

    Science.gov (United States)

    Kaden, Ute Susanne; Székely, Balázs; Wiche, Oliver

    2015-04-01

    In order to investigate the influence of the phosphorus nutritional status on the uptake of germanium (Ge) in biomass two species, white millet (Panicum miliaceum) and white mustard (Brassica alba) were grown and sampled in a greenhouse experiment. The cultivation took place on two different substrates. The plants were fertilized with different nutrient solutions which differed in their phosphate content, and artificial addition of Ge was held via the casting solution. During the test period, measurements of the pH value, electric conductivity, and phosphate content of the soil solution were conducted. To transfer germanium from soil and plant material in solution, melting and microwave digestion processes were done. The experiment showed that in both species the additional Ge supply also leads to an increasing germanium content in the aboveground plant material. The two species, however, behave differently in response to this Ge supply. Panicum miliaceum accumulates Ge in the above-ground parts of plants stem, leaf and fruit to a much greater extent than Brassica alba. On the other hand the Ge accumulation in the roots of both B. alba and P. miliaceum was very high. In case of B. alba the root content was found by far higher as compared to the other parts of the plant. The addition of phosphate in the system changes the behavior. Without additional Ge its natural uptake from soil decreases in both species but in B. alba it is more characteristic. Increasing Ge supply (for both species) leads to an increased Ge uptake, until it reaches a maximum, regardless of the presence of phosphate addition. Phosphate, on the other hand, has positive effects on Ge uptake only in the case of B. alba roots, and to a limited extent in roots of P. miliaceum. In addition, for Panicum miliaceum an increase of germanium mainly in the underground parts was achieved. A further addition of phosphate did not have a positive effect on a greater enrichment of germanium. Whereas in Brassica

  11. Nitrogen fertilization of switchgrass increases biomass yield and improves net greenhouse gas balance in northern Michigan, U.S.A

    International Nuclear Information System (INIS)

    Nikiema, Paligwende; Rothstein, David E.; Min, Doo-Hong; Kapp, Christian J.

    2011-01-01

    Nitrogen (N) fertilization can increase bioenergy crop production; however, fertilizer production and application can contribute to greenhouse gas (GHG) emissions, potentially undermining the GHG benefits of bioenergy crops. The objective of this study was to evaluate the effects of N fertilization on GHG emissions and biomass production of switchgrass bioenergy crop, in northern Michigan. Nitrogen fertilization treatments included 0 kg ha -1 (control), 56 kg ha -1 (low) and 112 kg ha -1 (high) of N applied as urea. Soil fluxes of CO 2 , N 2 O and CH 4 were measured every two weeks using static chambers. Indirect GHG emissions associated with field activities, manufacturing and transport of fertilizer and pesticides were derived from the literature. Switchgrass aboveground biomass yield was evaluated at the end of the growing season. Nitrogen fertilization contributed little to soil GHG emissions; relative to the control, there were additional global warming potential of 0.7 Mg ha -1 y -1 and 1.5 Mg ha -1 y -1 as CO 2 equivalents (CO 2 eq), calculated using the IPCC values, in the low and high N fertilization treatments, respectively. However, N fertilization greatly stimulated CO 2 uptake by switchgrass, resulting in 1.5- and 2.5-fold increases in biomass yield in the low and high N fertilization treatments, respectively. Nitrogen amendments improved the net GHG benefits by 2.6 Mg ha -1 y -1 and 9.4 Mg ha -1 y -1 as CO 2 eq relative to the control. Results suggest that N fertilization of switchgrass in this region could reduce (15-50%) the land base needed for bioenergy production and decrease pressure on land for food and forage crop production. -- Highlights: → We examine the effects of N fertilization of switchgrass on GHG emissions. → Effects of N fertilization on biomass production of switchgrass bioenergy crop. → N fertilization contributed little to greenhouse gas emissions. → N fertilization greatly stimulated CO 2 uptake by the switchgrass. → N

  12. Changes in Lignin Chemistry of Switchgrass due to Delignification by Sodium Hydroxide Pretreatment

    Directory of Open Access Journals (Sweden)

    Woochul Jung

    2018-02-01

    Full Text Available Switchgrass was pretreated with sodium hydroxide (NaOH at various concentrations and pretreatment times to investigate how delignification caused by NaOH affects its lignin chemistry. NaOH resulted in significant delignification ranging from 44.0 to 84.6% depending on pretreatment intensity. While there was no significant glucan loss due to NaOH pretreatment, higher NaOH concentrations removed xylan by up to 28.3%. Nitrobenzene oxidation (NBO was used to study changes in lignin chemistry, and indicated that at higher NaOH concentrations, the amount of 4-hydroxygenzaldehyde (Hy degraded from p-hydroxyphenyl propanol (H lignin units was significantly reduced (p < 0.05. However, amounts of syringic (SA and vanillic (VA acids generated from syringyl (S and guaiacyl (G degradation were greater at higher NaOH concentration. S/G ratio (=0.62 raw switchgrass did not significantly (p > 0.05 change with 15 min pretreatment, but it increased to 0.75 and 0.72, respectively, with 30 and 60 min pretreatments (p < 0.05. Increase in NaOH concentration did not significantly (p > 0.05 change S/G ratio, but H/G ratio (=0.48 raw switchgrass decreased significantly to 0.14 regardless of pretreatment times. Overall, the H unit was found to be more susceptible to NaOH than S and G unit monolignols. Though changes in lignin chemistry due to NaOH concentration were observed, their impact on cellulolytic enzyme action during hydrolysis could not be fully understood. Further studies on lignin isolation may help to determine how these changes in lignin chemistry by NaOH impact cellulolytic enzymes.

  13. The complex subcellular distribution of satellite panicum mosaic virus capsid protein reflects its multifunctional role during infection

    International Nuclear Information System (INIS)

    Qi Dong; Omarov, Rustem T.; Scholthof, Karen-Beth G.

    2008-01-01

    Satellite panicum mosaic virus (SPMV) depends on its helper Panicum mosaic virus for replication and movement in host plants. The positive-sense single-stranded genomic RNA of SPMV encodes a 17-kDa capsid protein (CP) to form 16-nm virions. We determined that SPMV CP accumulates in both cytosolic and non-cytosolic fractions, but cytosolic accumulation of SPMV CP is exclusively associated with virions. An N-terminal arginine-rich motif (N-ARM) on SPMV CP is used to bind its cognate RNA and to form virus particles. Intriguingly, virion formation is dispensable for successful systemic SPMV RNA accumulation, yet this process still depends on an intact N-ARM. In addition, a C-terminal domain on the SPMV CP is necessary for self-interaction. Biochemical fractionation and fluorescent microscopy of green fluorescent protein-tagged SPMV CP demonstrated that the non-cytosolic SPMV CP is associated with the cell wall, the nucleus and other membranous organelles. To our knowledge, this is the first report that a satellite virus CP not only accumulates exclusively as virions in the cytosol but also is directed to the nucleolus and membranes. That SPMV CP is found both in the nucleus and the cell wall suggests its involvement in viral nuclear import and cell-to-cell transport

  14. Produtividade do Panicum maximum cv. Mombaça irrigado, sob pastejo rotacionado

    Directory of Open Access Journals (Sweden)

    Müller Marcela dos Santos

    2002-01-01

    Full Text Available O uso da irrigação em pastagens é uma realidade fundamentada na experiência empírica de produtores, devido à falta de bases científicas definidas sobre o assunto. O trabalho visou avaliar a produtividade do capim Mombaça (Panicum maximum Jacq. cv. Mombaça manejado em pastejo rotacionado, sob sistema de irrigação e as principais variáveis climáticas responsáveis pelo acúmulo de massa de forragem. O experimento foi conduzido sob irrigação por aspersão tipo pivô central, de julho a dezembro de 1998, em região de cerrado (Latossolo Vermelho-Amarelo em São Desidério, BA. Foi quantificada a massa de forragem da pastagem aos 30 dias de crescimento e antes do pastejo e desenvolvidos modelos matemáticos que relacionam a produção de forragem a variáveis climáticas. A produção e a taxa de acúmulo de matéria seca da pastagem, ao longo do período de inverno não apresentaram diferenças significativas. Na primavera, houve tendência de aumento em ambas, com maiores produções obtidas no período final de avaliação. As menores taxas de acúmulo durante a primavera foram observadas nos primeiros piquetes, coincidindo com a ocorrência de baixas temperaturas durante o período de descanso. Com a elevação da temperatura mínima, a produção forrageira entrou em fase de acúmulo crescente. A produção de forragem, durante a primavera, foi superior à do inverno, apresentando incrementos em função da maior temperatura mínima do ar, do período de descanso e da área foliar inicial. As principais variáveis climáticas responsáveis pela produção da forragem foram temperatura mínima do ar e disponibilidade de água no solo.

  15. Predicted avian responses to bioenergy development scenarios in an intensive agricultural landscape

    Science.gov (United States)

    Uden, Daniel R.; Allen, Craig R.; Mitchell, Rob B.; McCoy, Tim D.; Guan, Qingfeng

    2015-01-01

    Conversion of native prairie to agriculture has increased food and bioenergy production but decreased wildlife habitat. However, enrollment of highly erodible cropland in conservation programs has compensated for some grassland loss. In the future, climate change and production of second-generation perennial biofuel crops could further transform agricultural landscapes and increase or decrease grassland area. Switchgrass (Panicum virgatum) is an alternative biofuel feedstock that may be economically and environmentally superior to maize (Zea mays) grain for ethanol production on marginally productive lands. Switchgrass could benefit farmers economically and increase grassland area, but there is uncertainty as to how conversions between rowcrops, switchgrass monocultures and conservation grasslands might occur and affect wildlife. To explore potential impacts on grassland birds, we developed four agricultural land-use change scenarios for an intensively cultivated landscape, each driven by potential future climatic changes and ensuing irrigation limitations, ethanol demand, commodity prices, and continuation of a conservation program. For each scenario, we calculated changes in area for landcover classes and predicted changes in grassland bird abundances. Overall, birds responded positively to the replacement of rowcrops with switchgrass and negatively to the conversion of conservation grasslands to switchgrass or rowcrops. Landscape context and interactions between climate, crop water use, and irrigation availability could influence future land-use, and subsequently, avian habitat quality and quantity. Switchgrass is likely to provide higher quality avian habitat than rowcrops but lower quality habitat than conservation grasslands, and therefore, may most benefit birds in heavily cultivated, irrigation dependent landscapes under warmer and drier conditions, where economic profitability may also encourage conversions to drought tolerant bioenergy feedstocks.

  16. Evaluation of biogas production potential by dry anaerobic digestion of switchgrass--animal manure mixtures.

    Science.gov (United States)

    Ahn, H K; Smith, M C; Kondrad, S L; White, J W

    2010-02-01

    Anaerobic digestion is a biological method used to convert organic wastes into a stable product for land application with reduced environmental impacts. The biogas produced can be used as an alternative renewable energy source. Dry anaerobic digestion [>15% total solid (TS)] has an advantage over wet digestion (produces a fertilizer that is easier to transport. Performance of anaerobic digestion of animal manure-switchgrass mixture was evaluated under dry (15% TS) and thermophilic conditions (55 degrees C). Three different mixtures of animal manure (swine, poultry, and dairy) and switchgrass were digested using batch-operated 1-L reactors. The swine manure test units showed 52.9% volatile solids (VS) removal during the 62-day trial, while dairy and poultry manure test units showed 9.3% and 20.2%, respectively. Over the 62 day digestion, the swine manure test units yielded the highest amount of methane 0.337 L CH4/g VS, while the dairy and poultry manure test units showed very poor methane yield 0.028 L CH4/g VS and 0.002 L CH4/g VS, respectively. Although dairy and poultry manure performed poorly, they may still have high potential as biomass for dry anaerobic digestion if appropriate designs are developed to prevent significant volatile fatty acid (VFA) accumulation and pH drop.

  17. Life Cycle Assessment of Switchgrass Cellulosic Ethanol Production in the Wisconsin and Michigan Agricultural Contexts

    Energy Technology Data Exchange (ETDEWEB)

    Sinistore, Julie C.; Reinemann, D. J.; Izaurralde, Roberto C.; Cronin, Keith R.; Meier, Paul J.; Runge, Troy M.; Zhang, Xuesong

    2015-04-25

    Spatial variability in yields and greenhouse gas emissions from soils has been identified as a key source of variability in life cycle assessments (LCAs) of agricultural products such as cellulosic ethanol. This study aims to conduct an LCA of cellulosic ethanol production from switchgrass in a way that captures this spatial variability and tests results for sensitivity to using spatially averaged results. The Environment Policy Integrated Climate (EPIC) model was used to calculate switchgrass yields, greenhouse gas (GHG) emissions, and nitrogen and phosphorus emissions from crop production in southern Wisconsin and Michigan at the watershed scale. These data were combined with cellulosic ethanol production data via ammonia fiber expansion and dilute acid pretreatment methods and region-specific electricity production data into an LCA model of eight ethanol production scenarios. Standard deviations from the spatial mean yields and soil emissions were used to test the sensitivity of net energy ratio, global warming potential intensity, and eutrophication and acidification potential metrics to spatial variability. Substantial variation in the eutrophication potential was also observed when nitrogen and phosphorus emissions from soils were varied. This work illustrates the need for spatially explicit agricultural production data in the LCA of biofuels and other agricultural products.

  18. Industrial hemp as a potential bioenergy crop in comparison with kenaf, switchgrass and biomass sorghum.

    Science.gov (United States)

    Das, Lalitendu; Liu, Enshi; Saeed, Areej; Williams, David W; Hu, Hongqiang; Li, Chenlin; Ray, Allison E; Shi, Jian

    2017-11-01

    This study takes combined field trial, lab experiment, and economic analysis approaches to evaluate the potential of industrial hemp in comparison with kenaf, switchgrass and biomass sorghum. Agronomy data suggest that the per hectare yield (5437kg) of industrial hemp stem alone was at a similar level with switchgrass and sorghum; while the hemp plants require reduced inputs. Field trial also showed that ∼1230kg/ha hemp grain can be harvested in addition to stems. Results show a predicted ethanol yield of ∼82gallons/dry ton hemp stems, which is comparable to the other three tested feedstocks. A comparative cost analysis indicates that industrial hemp could generate higher per hectare gross profit than the other crops if both hemp grains and biofuels from hemp stem were counted. These combined evaluation results demonstrate that industrial hemp has great potential to become a promising regional commodity crop for producing both biofuels and value-added products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. The economical and environmental performance of miscanthus and switchgrass production and supply chains in a European setting

    NARCIS (Netherlands)

    Smeets, E.M.W.|info:eu-repo/dai/nl/311445217; Lewandowski, I.M.; Faaij, A.P.C.|info:eu-repo/dai/nl/10685903X

    2009-01-01

    The purpose of this study is to analyse the economical and environmental performance of switchgrass and miscanthus production and supply chains in the European Union (EU25), for the years 2004 and 2030. The environmental performance refers to the greenhouse gas (GHG) emissions, the primary fossil

  20. Economic potential for switchgrass production in the U.S. Northern Plains: A minimum-data analysis

    Science.gov (United States)

    There is a demand for timely information to support policy decision making. There is also interest in the potential for alternative crops such as switchgrass to be used for ethanol production and which would have a positive impact on net greenhouse gas emission. This paper uses a new minimum-data mo...

  1. Effects of light intensity on growth, anatomy and forage quality of two tropical grasses (Brachiaria brizantha and Panicum maximum var. trichoglume).

    NARCIS (Netherlands)

    Deinum, B.; Sulastri, R.D.; Zeinab, M.H.J.; Maassen, A.

    1996-01-01

    Effects of light intensity on growth, histology and anatomy, and nutritive value were studied in seedlings of two shade tolerant species: Brachiaria brizantha and Panicum maximum var. trichoglume. They were studied under greenhouse conditions in pots with sandy soil and sufficient N and cut after a

  2. Queilite angular traumática em eqüinos associada à ingestão de Panicum maximum Angular cheilitis in horses associated with ingestion of Panicum maximum

    Directory of Open Access Journals (Sweden)

    José Diomedes Barbosa

    2009-05-01

    Full Text Available Uma condição com aumento da fenda bucal de eqüinos por lesão na comissura labial foi estudada. Este aumento tinha extensão variável e era uni ou bilateral. Na mucosa da bochecha da comissura labial exposta havia pequenas erosões. Durante a mastigação havia perda de pequena quantidade de capim e saliva pela fenda bucal aumentada. Os animais apresentavam bom estado nutricional. O exame histopatológico de tecido retirado da comissura labial revelou epidermite superficial. Nas quatro propriedades onde se verificou o problema, constatou-se que os eqüinos eram mantidos em sistema extensivo de criação em pastagem de Panicum maximum (variedades Tanzânia, Mombaça, Tobiatã e Colonião, com folhas maduras, altas, lignificadas e de bordos cortantes. De acordo com os dados epidemiológicos, com os achados clínicos e histopatológicos, concluí-se que essas lesões foram causadas pela ação cortante das folhas de Panicum maximum, associada à forma de apreensão da pastagem alta e mastigação pelos eqüinos.A condition with enlargement of the oral cleft in horses was studied. The enlargement of varied extension was uni or bilateral. The cheek mucosa of the labial commissure showed slight erosions. During chewing there was loss of small amounts of grass and saliva through the oral cleft. The affected horses were in good nutritional condition. Histopathological studies of tissues obtained by biopsia, revealed a superficial epidermitis. The pastures consisted of Panicum maximum grass (varieties Tanzânia, Mombaça, Tobiatã and Colonião which was mature, tall, lignified, with leaves of cutting edges. Based on epidemiological, clinical and histopathological data, it was concluded that the lesions were caused by the hard grass, favored by the way horses pull the tall grass and chew it.

  3. Microbial nitrogen cycling response to forest-based bioenergy production.

    Science.gov (United States)

    Minick, Kevan J; Strahm, Brian D; Fox, Thomas R; Sucre, Eric B; Leggett, Zakiya H

    2015-12-01

    Concern over rising atmospheric CO2 and other greenhouse gases due to fossil fuel combustion has intensified research into carbon-neutral energy production. Approximately 15.8 million ha of pine plantations exist across the southeastern United States, representing a vast land area advantageous for bioenergy production without significant landuse change or diversion of agricultural resources from food production. Furthermore, intercropping of pine with bioenergy grasses could provide annually harvestable, lignocellulosic biomass feedstocks along with production of traditional wood products. Viability of such a system hinges in part on soil nitrogen (N) availability and effects of N competition between pines and grasses on ecosystem productivity. We investigated effects of intercropping loblolly pine (Pinus taeda) with switchgrass (Panicum virgatum) on microbial N cycling processes in the Lower Coastal Plain of North Carolina, USA. Soil samples were collected from bedded rows of pine and interbed space of two treatments, composed of either volunteer native woody and herbaceous vegetation (pine-native) or pure switchgrass (pine-switchgrass) in interbeds. An in vitro 15N pool-dilution technique was employed to quantify gross N transformations at two soil depths (0-5 and 5-15 cm) on four dates in 2012-2013. At the 0-5 cm depth in beds of the pine-switchgrass treatment, gross N mineralization was two to three times higher in November and February compared to the pine-native treatment, resulting in increased NH4(+) availability. Gross and net nitrification were also significantly higher in February in the same pine beds. In interbeds of the pine-switchgrass treatment, gross N mineralization was lower from April to November, but higher in February, potentially reflecting positive effects of switchgrass root-derived C inputs during dormancy on microbial activity. These findings indicate soil N cycling and availability has increased in pine beds of the pine-switchgrass

  4. Neutron Imaging Reveals Internal Plant Hydraulic Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Jeffrey [ORNL; Bilheux, Hassina Z [ORNL; Kang, Misun [ORNL; Voisin, Sophie [ORNL; Cheng, Chu-Lin [ORNL; Horita, Jusuke [ORNL; Perfect, Edmund [ORNL

    2013-01-01

    Many terrestrial ecosystem processes are constrained by water availability and transport within the soil. Knowledge of plant water fluxes is thus critical for assessing mechanistic processes linked to biogeochemical cycles, yet resolution of root structure and xylem water transport dynamics has been a particularly daunting task for the ecologist. Through neutron imaging, we demonstrate the ability to non-invasively monitor individual root functionality and water fluxes within Zea mays L. (maize) and Panicum virgatum L. (switchgrass) seedlings growing in a sandy medium. Root structure and growth were readily imaged by neutron radiography and neutron computed tomography. Seedlings were irrigated with water or deuterium oxide and imaged through time as a growth lamp was cycled on to alter leaf demand for water. Sub-millimeter scale resolution reveals timing and magnitudes of root water uptake, redistribution within the roots, and root-shoot hydraulic linkages, relationships not well characterized by other techniques.

  5. Anaerobic decomposition of switchgrass by tropical soil-derived feedstock-adapted consortia.

    Science.gov (United States)

    DeAngelis, Kristen M; Fortney, Julian L; Borglin, Sharon; Silver, Whendee L; Simmons, Blake A; Hazen, Terry C

    2012-01-01

    Tropical forest soils decompose litter rapidly with frequent episodes of anoxic conditions, making it likely that bacteria using alternate terminal electron acceptors (TEAs) play a large role in decomposition. This makes these soils useful templates for improving biofuel production. To investigate how TEAs affect decomposition, we cultivated feedstock-adapted consortia (FACs) derived from two tropical forest soils collected from the ends of a rainfall gradient: organic matter-rich tropical cloud forest (CF) soils, which experience sustained low redox, and iron-rich tropical rain forest (RF) soils, which experience rapidly fluctuating redox. Communities were anaerobically passed through three transfers of 10 weeks each with switchgrass as a sole carbon (C) source; FACs were then amended with nitrate, sulfate, or iron oxide. C mineralization and cellulase activities were higher in CF-FACs than in RF-FACs. Pyrosequencing of the small-subunit rRNA revealed members of the Firmicutes, Bacteroidetes, and Alphaproteobacteria as dominant. RF- and CF-FAC communities were not different in microbial diversity or biomass. The RF-FACs, derived from fluctuating redox soils, were the most responsive to the addition of TEAs, while the CF-FACs were overall more efficient and productive, both on a per-gram switchgrass and a per-cell biomass basis. These results suggest that decomposing microbial communities in fluctuating redox environments are adapted to the presence of a diversity of TEAs and ready to take advantage of them. More importantly, these data highlight the role of local environmental conditions in shaping microbial community function that may be separate from phylogenetic structure. After multiple transfers, we established microbial consortia derived from two tropical forest soils with different native redox conditions. Communities derived from the rapidly fluctuating redox environment maintained a capacity to use added terminal electron acceptors (TEAs) after multiple

  6. CINÉTICA DE DEGRADABILIDAD in vitro DE CUATRO VARIEDADES DE Panicum maximum COSECHADAS A CUATRO EDADES

    Directory of Open Access Journals (Sweden)

    Juan Humberto Avellaneda Cevallos

    2015-12-01

    Full Text Available Se evaluó la degradabilidad in vitro de la materia seca (MS de las hojas, tallos y planta completa de cuatro variedades de pasto Guinea (Panicum maximum: Común, Tanzania, Enano y Tobiata en cuatro edades de cosecha (21, 42, 63 y 84 d. Se evaluó la composición química de las variedades. Para la digestibilidad in vitro, se empleó la primera fase de la técnica de Tilley y Terry, para lo cual se extrajo líquido ruminal de dos bovinos Brown Swiss canulados a rumen. Se evaluaron seis periodos de incubación (3, 6, 12, 24, 48 y 72 h. Para la cinética de degradación in vitro, se aplicó un diseño de bloques completos al azar (DBCA, utilizando a la corrida (2 como criterio de bloqueo y repetición; se usó una incubadora DaisyII 200 y una bolsita de degradabilidad por corrida. Se observó que la mejor degradabilidad in vitro se presenta en los primeros estadios fenológicos, y que las hojas demuestran mayores características nutricionales, seguida de la planta completa y tallos. Se demostró que las diferencias en degradabilidad no están fuertemente asociadas con la variedad de Panicum maximum, sino más bien con la edad de cosecha. Por lo que se concluye, que la degradabilidad in vitro de las variedades de pasto Guinea, difieren en función del estado de madurez de la planta.

  7. Comparative Genomics in Switchgrass Using 61,585 High-Quality Expressed Sequence Tags

    Directory of Open Access Journals (Sweden)

    Christian M. Tobias

    2008-11-01

    Full Text Available The development of genomic resources for switchgrass ( L., a perennial NAD-malic enzyme type C grass, is required to enable molecular breeding and biotechnological approaches for improving its value as a forage and bioenergy crop. Expressed sequence tag (EST sequencing is one method that can quickly sample gene inventories and produce data suitable for marker development or analysis of tissue-specific patterns of expression. Toward this goal, three cDNA libraries from callus, crown, and seedling tissues of ‘Kanlow’ switchgrass were end-sequenced to generate a total of 61,585 high-quality ESTs from 36,565 separate clones. Seventy-three percent of the assembled consensus sequences could be aligned with the sorghum [ (L. Moench] genome at a -value of <1 × 10, indicating a high degree of similarity. Sixty-five percent of the ESTs matched with gene ontology molecular terms, and 3.3% of the sequences were matched with genes that play potential roles in cell-wall biogenesis. The representation in the three libraries of gene families known to be associated with C photosynthesis, cellulose and β-glucan synthesis, phenylpropanoid biosynthesis, and peroxidase activity indicated likely roles for individual family members. Pairwise comparisons of synonymous codon substitutions were used to assess genome sequence diversity and indicated an overall similarity between the two genome copies present in the tetraploid. Identification of EST–simple sequence repeat markers and amplification on two individual parents of a mapping population yielded an average of 2.18 amplicons per individual, and 35% of the markers produced fragment length polymorphisms.

  8. LIGNOCELLULOSIC BIOMASS AFTER EXPLOSIVE AUTOHYDROLYSIS AS SUBSTRATE TO BUTANOL OBTAINING

    Directory of Open Access Journals (Sweden)

    Tigunova

    2016-08-01

    Full Text Available The aim of the work was investigation of the effect of the explosive autohydrolysis on lignocellulosic biomass (saving, switchgrass biomass for consequent use as a substrate to produce biofuels such as butanol. Butanol-producing strains, switchgrass Panicum virgatum L. biomass and its components after autohydrolysis were used in study. The thermobaric pressure pretreatment of lignocellulosic biomass was carried out using specially designed equipment. The effect of explosive autohydrolysis on lignocellulosic biomass for further use in producing biofuels using microbial conversion was studied. Components of lignocellulosic biomass were fractionated after undergoing thermobaric treatment. The possibility of using different raw material components after using explosive autohydrolysis processing to produce biobutanol was found. Products of switchgrass biomass autohydrolysis were shown to need further purification before fermentation from furfural formed by thermobaric pretreatment and inhibiting the growth of microorganisms. The ability of strains of the genus Clostridium to use cellulose as a substrate for fermentation was proved. It was found that using explosive autohydrolysis pretreatment to savings allowed boosting the butanol accumulation by 2 times.

  9. Nitrogen recycling in prairie species managed for biomass production

    Science.gov (United States)

    Smith, L.; Jackson, R. D.

    2011-12-01

    Plant nutrient recycling is an important mechanism for nitrogen (N) retention in plants and has been identified as a means for reducing N losses in perennial grass systems managed for biomass production. Warm-season (C4 photosynthesis) prairie grasses are thought to be inherently good at recycling N, because they often thrive in nutrient-limited native grasslands where N recycling strategies would be advantageous. Results from studies of plant responses to altered N resources and the subsequent ability or need for plants to resorb N in high-productivity environments have been equivocal. We addressed N resorption of four species -- Panicum virgatum in a switchgrass monoculture, and Andropogen gerardii, Sorghastrum nutans and Helianthus grosseserratus in a restored prairie -- and their responses to fertilizer additions of 0, 50, or 150 kg N ha-1 on productive mollisols. We hypothesized that senesced leaf N (the final N concentration retained in a senesced leaf) would increase with fertility, while N resorption efficiency (the proportion of original green leaf N resorbed after senescence) would decrease with fertility. N resorption efficiency rates in the prairie differed mainly by species without significant treatment effects. Helianthus grosseserratus resorption efficiency was highest (69.0 ± 2.6% [s.e.]), followed by Sorghastrum nutans (47.9 ± 5.4%) and Andropogen gerardii (35.3 ± 5.7%). Panicum virgatum resorption efficiencies responded opposite to our predictions with the highest resorption rates in the high-fertility treatment (62.9 ± 5.7%) and the lowest resorption rates in the unfertilized treatment (49.4 ± 6.1%). Fertilizer effects were only significant in senesced Panicum virgatum leaves, but across all species, plants with high green leaf N tended to also have higher senesced leaf N. This suggests that plants with high N resorption efficiencies may resorb a higher proportion of original leaf N because there is more N to remobilize. However, these

  10. Effets de Panicum maximum Jacq. associé à Euphorbia heterophylla (L.) Klotz. & Garcke sur la productivité des femelles durant le cycle de reproduction chez le cobaye (Cavia porcellus L.)

    OpenAIRE

    N'G. D.V. Kouakou; Thys, E.; Yapi, YM.; Assidjo, EN.; Marnet, PG.; Grongnet, JF.

    2015-01-01

    Effect of Panicum maximum Jacq. Associated with Euphorbia heterophylla (L.) Klotz. & Garcke on Productivity of Females (Cavia porcellus L) During the Reproductive Cycle. In Ivory Coast, Guinea pigs reared for meat (Cavia porcellus L.) are mainly fed with Panicum maximum Jacq. The association of this forage with Euphorbia heterophylla (L.) Klotz. & Garcke improves the organic matter digestibility of the mixed diet compared to P. maximum distributed alone in growing male guinea pigs. In order t...

  11. Life Cycle Costs and Life Cycle Assessment for the Harvesting, Conversion, and the Use of Switchgrass to Produce Electricity

    OpenAIRE

    Lerkkasemsan, Nuttapol; Achenie, Luke E. K.

    2013-01-01

    This paper considers both LCA and LCC of the pyrolysis of switchgrass to use as an energy source in a conventional power plant. The process consists of cultivation, harvesting, transportation, storage, pyrolysis, transportation, and power generation. Here pyrolysis oil is converted to electric power through cocombustion in conventional fossil fuel power plants. Several scenarios are conducted to determine the effect of selected design variables on the production of pyrolysis oil and type of c...

  12. Soil and variety effects on energy use and carbon emissions associated with switchgrass-based ethanol production in Mississippi

    Energy Technology Data Exchange (ETDEWEB)

    Woli, Prem; Paz, Joel O.; Baldwin, Brian S.; Lang, David J.; Kiniry, James R.

    2012-06-29

    High biomass production potential, wide adaptability, low input requirement, and low environmental risk make switchgrass an economically and ecologically viable energy crop.The inherent variablity in switchgrass productivity due to variations in soil and variety could affect the sustainability and eco-friendliness of switchgrass-based ethanol production. This study examined the soil and variety effects on these variables. Three locations in Mississippi were selected based on latitude and potential acreage. Using ALMANAC, switchgrass biomass yields were simulated for several scenarios of soils and varities. The simulated yields were fed to IBSAL to compute energy use and CO2 emissions in various operations in the biomass supply From the energy and emissions values, the sustainability and eco-friendliness of ethanol production were determined using net energy value (NEV) and carbon credit balance (CCB) as indicators, respectively. Soil and variety effects on NEV and CCB were analyzed using the Kruskal-Wallis test. Results showed significant differences in NEV and CCB across soils and varieties. Both NEV and CCB increased in the direction of heavier to lighter soils and on the order of north-upland , south-upland, north-lowland, and south-lowland varieties. Only north-upland and south-lowland varieties were significantly significantly different because they were different in both cytotype and ecotype. Gaps between lowland and upland varieties were smaller in a dry year than in a wet year. The NEV and CCB increased in the direction of dry to wet year. From south to north, they decreased for lowland cytotypes but increased for upland cytotypes. Thus, the differences among varieties decreased northwards.

  13. Mapeamento da distribuição espacial da infestação de Panicum maximum durante a colheita da cultura de milho Mapping of the spatial distribution of Panicum maximum during corn harvesting

    Directory of Open Access Journals (Sweden)

    L.S. Shiratsuchi

    2004-06-01

    Full Text Available Metodologias de mapeamento de plantas daninhas em áreas agrícolas estão sendo utilizados a fim de gerar mapas de aplicação localizada de herbicidas, sendo que, este mapeamento vem sendo feito através de ferramentas da agricultura de precisão. O mapeamento das plantas daninhas gera então mapas de tratamentos de herbicidas que comandam pulverizadores capazes de realizar a aplicação localizada de herbicidas, aproveitando o comportamento contagioso inerente da comunidade das plantas daninhas, porém poucos experimentos relatam a eficiência desses métodos. Este experimento teve como objetivo comparar metodologias de mapeamento do capim-colonião (Panicum maximum, com base na avaliação visual durante e após a colheita da cultura de milho. Durante a colheita foi conduzido o monitoramento com avaliação visual, feito por uma pessoa devidamente treinada e pelo operador antecipadamente orientado. Após a colheita, a avaliação visual foi feita por amostragens, numa grade regular de 20 x 20 m. Foi observada uma subestimação de 6% da área infestada, com uma infestação de mais de 80% de cobertura pelo método de mapeamento durante a colheita, quando comparado com o caminhamento na grade regular após a colheita. Os dois métodos foram coincidentes em 45% da área marcada.Weed mapping methodologies are being tested in agricultural fields to generate maps of spotted application of herbicides by using precision farming tools. Weed mapping may generate herbicide treatment maps, allowing herbicide spray only where needed. However, few experiments have reported the efficiency of these methods. This research aimed to compare Panicum maximum mapping methodologies based on visual assessment during and after corn harvesting. Monitoring combined with visual assessment was performed during harvesting by a duly trained worker and a previously oriented operator. Visual assessment was done by samplings after harvesting in a regular 20 x 20 m grid. An

  14. Imbalanced carbon-for-phosphorus exchange between European arbuscular mycorrhizal fungi and non-native Panicum grasses-A case of dysfunctional symbiosis

    Czech Academy of Sciences Publication Activity Database

    Řezáčová, Veronika; Slavíková, Renata; Konvalinková, Tereza; Hujslová, Martina; Gryndlerová, Hana; Gryndler, Milan; Püschel, David; Jansa, Jan

    2017-01-01

    Roč. 62, May 2017 (2017), s. 48-55 ISSN 0031-4056 R&D Projects: GA MŠk(CZ) LK11224; GA ČR(CZ) GA14-19191S Grant - others:AV ČR(CZ) Fellowship J. E. Purkyně Institutional support: RVO:61388971 Keywords : Arbuscular mycorrhiza * Panicum * Plant biomass Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 2.000, year: 2016

  15. Effet de Panicum maximum sur la productivité des femelles primipares durant le cycle de reproduction chez le cobaye (Cavia porcellus L.

    Directory of Open Access Journals (Sweden)

    Danho, M.

    2012-01-01

    Full Text Available Effect of Panicum maximum on Productivity of Primiparous Females during Reproduction Cycle in Guinea Pigs (Cavia porcellus L.. In Ivory Coast, Guinea pigs reared for meat (Cavia porcellus L. are mainly fed with Panicum maximum. To assess the effect of the latter during pregnancy and lactation (RC of these animals, primiparous dams were fed ad libitum, Panicum maximum alone during the RC (MOD1 or associated with pellets for rabbits during lactation (MOD2, or associated with pellets for rabbits during the last part of the pregnancy period and the lactation (MOD3, or associated with pellets for rabbits during the entire RC (MOD4. The number of corpora lutea per female was 1.3 ± 0.5 and 2.0 ± 0.0 respectively for MOD1 and MOD4. No pre-embryonic mortality was recorded. The mean weight of the young guinea pigs of MOD1 (54.7 ± 10. g was only 55% of that of MOD4 (98.6 ± 13.6 g. At weaning, the average weight gain of young guinea pigs of MOD1 (40.5 ± 22.2 g represented a third of those obtained with other diets that did not significantly differ. At the end of RC, the weight gain of dams was 17 ± 13.3% for MOD1 compared to 50% for MOD2, MOD3 and MOD4. Feeding Panicum maximum alone induces chronic malnutrition which in turn is responsible of the low ovulation rate and reduced growth in guinea pig breeding.

  16. Genetic Improvement of Switchgrass and Other Herbaceous Plants for Use as Biomass Fuel Feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, K.P.

    2001-01-11

    It should be highly feasible to genetically modify the feedstock quality of switchgrass and other herbaceous plants using both conventional and molecular breeding techniques. Effectiveness of breeding to modify herbages of switchgrass and other perennial and annual herbaceous species has already been demonstrated. The use of molecular markers and transformation technology will greatly enhance the capability of breeders to modify the plant structure and cell walls of herbaceous plants. It will be necessary to monitor gene flow to remnant wild populations of plants and have strategies available to curtail gene flow if it becomes a potential problem. It also will be necessary to monitor plant survival and long-term productivity as affected by genetic changes that improve forage quality. Information on the conversion processes that will be used and the biomass characteristics that affect conversion efficiency and rate is absolutely essential as well as information on the relative economic value of specific traits. Because most forage or biomass quality characteristics are highly affected by plant maturity, it is suggested that plant material of specific maturity stages be used in research to determining desirable feedstock quality characteristics. Plant material could be collected at various stages of development from an array of environments and storage conditions that could be used in conversion research. The same plant material could be used to develop NIRS calibrations that could be used by breeders in their selection programs and also to develop criteria for a feedstock quality assessment program. Breeding for improved feedstock quality will likely affect the rate of improvement of biomass production per acre. If the same level of resources are used, multi-trait breeding simply reduces the selection pressure and hence the breeding progress that can be made for a single trait unless all the traits are highly correlated. Since desirable feedstock traits are likely

  17. Survival of Salmonella, Escherichia coli 0157:H7, non-0157 shiga toxin producing E.coli, and potential surrogate bacteria in crop soil as affected by the addition of fast pyrolysis-generated switchgrass biochar

    Science.gov (United States)

    Fast pyrolysis of switchgrass (and resultant biochar) can be used for bio-fuel production, soil amendments for fertilizing crops, binding heavy metals, and sequestering environmental biocarbon. To determine the influence of fast pyrolysis-generated switchgrass biochar on survival of foodborne path...

  18. Genetic Diversity and Population Structure of Broomcorn Millet (Panicum miliaceum L.) Cultivars and Landraces in China Based on Microsatellite Markers

    Science.gov (United States)

    Liu, Minxuan; Xu, Yue; He, Jihong; Zhang, Shuang; Wang, Yinyue; Lu, Ping

    2016-01-01

    Broomcorn millet (Panicum miliaceum L.), one of the first domesticated crops, has been grown in Northern China for at least 10,000 years. The species is presently a minor crop, and evaluation of its genetic diversity has been very limited. In this study, we analyzed the genetic diversity of 88 accessions of broomcorn millet collected from various provinces of China. Amplification with 67 simple sequence repeat (SSR) primers revealed moderate levels of diversity in the investigated accessions. A total of 179 alleles were detected, with an average of 2.7 alleles per locus. Polymorphism information content and expected heterozygosity ranged from 0.043 to 0.729 (mean = 0.376) and 0.045 to 0.771 (mean = 0.445), respectively. Cluster analysis based on the unweighted pair group method of mathematical averages separated the 88 accessions into four groups at a genetic similarity level of 0.633. A genetic structure assay indicated a close correlation between geographical regions and genetic diversity. The uncovered information will be valuable for defining gene pools and developing breeding programs for broomcorn millet. Furthermore, the millet-specific SSR markers developed in this study should serve as useful tools for assessment of genetic diversity and elucidation of population structure in broomcorn millet. PMID:26985894

  19. Invertebrate fauna associated with Torpedograss, Panicum repens (Cyperales: Poaceae), in Lake Okeechobee, Florida, and prospects for biological control

    International Nuclear Information System (INIS)

    Cuda, J.P.; Dunford, J.C.; Leavengood, J.M. Jr.

    2007-01-01

    Torpedograss, Panicum repens L., is an adventive, rhizomatous grass species that has become an invasive weed of terrestrial, wetland, and aquatic environments in tropical and subtropical regions worldwide. Until recently, strategies for controlling torpedograss in the USA have focused almost exclusively on mechanical and chemical methods, either alone or in combination, with varied results. A survey of the arthropods and nematodes currently associated with the plant in Lake Okeechobee, Florida, was conducted as part of a feasibility study to determine whether torpedograss is an appropriate target for a classical biological control program. Overall, approximately 4,000 arthropods and 400 nematode specimens were collected. Sweep, clipped vegetation, and soil core samples were dominated by representatives of the arthropod orders Hemiptera, Hymenoptera, Diptera, and Acari. Lesion nematodes of the genus Pratylenchus were commonly associated with the roots of torpedograss. None of the organisms collected were torpedograss specialists. Although classical biological control of torpedograss is feasible based on the extent of the infestation, economic losses, resistance to conventional controls, and the report of a potentially host specific natural enemy in India, the botanical position of this grass weed will require a formal risk assessment before proceeding with a classical biological control program. (author) [es

  20. DINAMICA POBLACIONAL DE Panicum polygonatum Y Axonopus micay BAJO COMBATE CON HERBICIDAS Y CHAPEA, EN UNA PLANTACIÓN BANANERA

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    Ana Mar\\u00EDa Rodr\\u00EDguez-Ruiz

    2011-01-01

    Full Text Available El objetivo de esta investigación fue determinar los cambios poblacionales de arvenses poáceas bajo combate químico y de chapea . El trabajo se realizó en una finca bananera en la zona de Cariari de Pococí, entre octubre del 2003 a setiembre 2005. Se estableció un experimento con un diseño de bloques al azar, con cuatro tratamie ntos: chapea s bimensuales, aplicaciones calendarizadas con glifosato, aplicaciones calendarizadas con glufosinato y tratamie nto monitoreado aplicado con base al monitoreo de las arvenses presentes. Las principa les poáceas registradas fueron Panicum polygonatum y Axonopus micay. Se realizaron recuentos de las arvenses cada dos meses. A partir de la segunda evaluación el glifosato tendió a disminuir de manera significativa las poblaciones de P. polygonatum, en tanto que la chapea favoreció el desarrollo de la misma; con los tratamie ntos de glufosinato y el monitoreado las poblaciones de la maleza se mantuvie ron intermedia s. Los tratamie ntos de glufosinato y la chapea aumentaron las poblaciones de A. micay.

  1. Hydrogen production from switchgrass via an integrated pyrolysis-microbial electrolysis process.

    Science.gov (United States)

    Lewis, A J; Ren, S; Ye, X; Kim, P; Labbe, N; Borole, A P

    2015-11-01

    A new approach to hydrogen production using an integrated pyrolysis-microbial electrolysis process is described. The aqueous stream generated during pyrolysis of switchgrass was used as a substrate for hydrogen production in a microbial electrolysis cell, achieving a maximum hydrogen production rate of 4.3 L H2/L anode-day at a loading of 10 g COD/L-anode-day. Hydrogen yields ranged from 50±3.2% to 76±0.5% while anode Coulombic efficiency ranged from 54±6.5% to 96±0.21%, respectively. Significant conversion of furfural, organic acids and phenolic molecules was observed under both batch and continuous conditions. The electrical and overall energy efficiency ranged from 149-175% and 48-63%, respectively. The results demonstrate the potential of the pyrolysis-microbial electrolysis process as a sustainable and efficient route for production of renewable hydrogen with significant implications for hydrocarbon production from biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Synthesis of three advanced biofuels from ionic liquid-pretreated switchgrass using engineered Escherichia coli

    Science.gov (United States)

    Bokinsky, Gregory; Peralta-Yahya, Pamela P.; George, Anthe; Holmes, Bradley M.; Steen, Eric J.; Dietrich, Jeffrey; Soon Lee, Taek; Tullman-Ercek, Danielle; Voigt, Christopher A.; Simmons, Blake A.; Keasling, Jay D.

    2011-01-01

    One approach to reducing the costs of advanced biofuel production from cellulosic biomass is to engineer a single microorganism to both digest plant biomass and produce hydrocarbons that have the properties of petrochemical fuels. Such an organism would require pathways for hydrocarbon production and the capacity to secrete sufficient enzymes to efficiently hydrolyze cellulose and hemicellulose. To demonstrate how one might engineer and coordinate all of the necessary components for a biomass-degrading, hydrocarbon-producing microorganism, we engineered a microorganism naïve to both processes, Escherichia coli, to grow using both the cellulose and hemicellulose fractions of several types of plant biomass pretreated with ionic liquids. Our engineered strains express cellulase, xylanase, beta-glucosidase, and xylobiosidase enzymes under control of native E. coli promoters selected to optimize growth on model cellulosic and hemicellulosic substrates. Furthermore, our strains grow using either the cellulose or hemicellulose components of ionic liquid-pretreated biomass or on both components when combined as a coculture. Both cellulolytic and hemicellulolytic strains were further engineered with three biofuel synthesis pathways to demonstrate the production of fuel substitutes or precursors suitable for gasoline, diesel, and jet engines directly from ionic liquid-treated switchgrass without externally supplied hydrolase enzymes. This demonstration represents a major advance toward realizing a consolidated bioprocess. With improvements in both biofuel synthesis pathways and biomass digestion capabilities, our approach could provide an economical route to production of advanced biofuels. PMID:22123987

  3. Potential of potassium hydroxide pretreatment of switchgrass for fermentable sugar production.

    Science.gov (United States)

    Sharma, Rajat; Palled, Vijaykumar; Sharma-Shivappa, Ratna R; Osborne, Jason

    2013-02-01

    Chemical pretreatment of lignocellulosic biomass has been extensively investigated for sugar generation and subsequent fuel production. Alkaline pretreatment has emerged as one of the popular chemical pretreatment methods, but most attempts thus far have utilized NaOH for the pretreatment process. This study aimed at investigating the potential of potassium hydroxide (KOH) as a viable alternative alkaline reagent for lignocellulosic pretreatment based on its different reactivity patterns compared to NaOH. Performer switchgrass was pretreated at KOH concentrations of 0.5-2% for varying treatment times of 6-48 h, 6-24 h, and 0.25-1 h at 21, 50, and 121 °C, respectively. The pretreatments resulted in the highest percent sugar retention of 99.26% at 0.5%, 21 °C, 12 h while delignification up to 55.4% was observed with 2% KOH, 121 °C, 1 h. Six pretreatment conditions were selected for subsequent enzymatic hydrolysis with Cellic CTec2® for sugar generation. The pretreatment condition of 0.5% KOH, 24 h, 21 °C was determined to be the most effective as it utilized the least amount of KOH while generating 582.4 mg sugar/g raw biomass for a corresponding percent carbohydrate conversion of 91.8%.

  4. Substrate-Specific Development of Thermophilic Bacterial Consortia by Using Chemically Pretreated Switchgrass.

    Science.gov (United States)

    Eichorst, Stephanie A; Joshua, Chijioke; Sathitsuksanoh, Noppadon; Singh, Seema; Simmons, Blake A; Singer, Steven W

    2014-12-01

    Microbial communities that deconstruct plant biomass have broad relevance in biofuel production and global carbon cycling. Biomass pretreatments reduce plant biomass recalcitrance for increased efficiency of enzymatic hydrolysis. We exploited these chemical pretreatments to study how thermophilic bacterial consortia adapt to deconstruct switchgrass (SG) biomass of various compositions. Microbial communities were adapted to untreated, ammonium fiber expansion (AFEX)-pretreated, and ionic-liquid (IL)-pretreated SG under aerobic, thermophilic conditions using green waste compost as the inoculum to study biomass deconstruction by microbial consortia. After microbial cultivation, gravimetric analysis of the residual biomass demonstrated that both AFEX and IL pretreatment enhanced the deconstruction of the SG biomass approximately 2-fold. Two-dimensional nuclear magnetic resonance (2D-NMR) experiments and acetyl bromide-reactive-lignin analysis indicated that polysaccharide hydrolysis was the dominant process occurring during microbial biomass deconstruction, and lignin remaining in the residual biomass was largely unmodified. Small-subunit (SSU) rRNA gene amplicon libraries revealed that although the dominant taxa across these chemical pretreatments were consistently represented by members of the Firmicutes, the Bacteroidetes, and Deinococcus-Thermus, the abundance of selected operational taxonomic units (OTUs) varied, suggesting adaptations to the different substrates. Combining the observations of differences in the community structure and the chemical and physical structure of the biomass, we hypothesize specific roles for individual community members in biomass deconstruction. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  5. Economic analysis of ethanol production from switchgrass using hybrid thermal/biological processing

    Energy Technology Data Exchange (ETDEWEB)

    So, K.S.; Brown, R.C. [Iowa State Univ., Ames, IA (United States). Center for Coal and the Environment; Scott, D.S. [Univ. of Waterloo, Ontario (Canada). Dept. of Chemical Engineering

    1998-12-31

    The economics of ethanol production from switchgrass using Waterloo fast pyrolysis with a fermentation step is investigated. Standard chemical engineering methods are used to estimate capital investment and operating costs. Order of magnitude method is employed for preliminary approximation of capital investment. The azeotropic ethanol production capacity used in this case study is 189 million liters/year (50 million gallons/year). All cost figures are updated to 1997 US $. Total capital investment is estimated to be $142 million, while the annual operating cost is about $118 million with an ethanol selling price of $0.62/l ($2.35/gal). This compares to $0.58/l ($2.20/gal) for ethanol from popular wood as determined in a previous study of the Waterloo fast pyrolysis process. Conservation of energy, especially, in the separation and purification steps, and generation of steam from lignin to meet energy requirements are evaluated in terms of energy saving costs. Additional steam has to be purchased, at $0.30 million/year, in order to meet the heat energy requirement of the process. Sensitivity analyses of feedstock cost and yield of sugar fermentation on the selling price of ethanol show that feedstock cost is positively related to ethanol selling price, while the yield has a negative relationship with selling price.

  6. Characterization of Biobased Polyurethane Foams Employing Lignin Fractionated from Microwave Liquefied Switchgrass

    Directory of Open Access Journals (Sweden)

    Xingyan Huang

    2017-01-01

    Full Text Available Lignin samples fractionated from microwave liquefied switchgrass were applied in the preparation of semirigid polyurethane (PU foams without purification. The objective of this study was to elucidate the influence of lignin in the PU matrix on the morphological, chemical, mechanical, and thermal properties of the PU foams. The scanning electron microscopy (SEM images revealed that lignin with 5 and 10% content in the PU foams did not influence the cell shape and size. The foam cell size became larger by increasing the lignin content to 15%. Fourier transform infrared spectroscopy (FTIR indicated that chemical interactions occurred between the lignin hydroxyl and isocyanate revealing that lignin was well dispersed in the matrix materials. The apparent density of the foam with 10% lignin increased by 14.2% compared to the control, while the foam with 15% lignin had a decreased apparent density. The effect of lignin content on the mechanical properties was similar to that on apparent density. The lignin containing foams were much more thermally stable than the control foam as evidenced by having higher initial decomposition temperature and maximum decomposition rate temperature from the thermogravimetric analysis (TGA profiles.

  7. Comparison of different pretreatments for the production of bioethanol and biomethane from corn stover and switchgrass.

    Science.gov (United States)

    Papa, G; Rodriguez, S; George, A; Schievano, A; Orzi, V; Sale, K L; Singh, S; Adani, F; Simmons, B A

    2015-05-01

    In this study the efficiency of mild ionic liquid (IL) pretreatment and pressurized hot water (PHW) is evaluated and compared in terms of bioethanol and biomethane yields, with corn stover (CS) and switchgrass (SG) as model bioenergy crops. Both feedstocks pretreated with the IL 1-ethyl-3-methylimidazolium acetate [C2C1Im][OAc] at 100°C for 3h exhibited lower glucose yield that those treated with harsher pretreatment conditions previously used. Compared to PHW, IL pretreatment demonstrated higher bioethanol yields; moreover IL pretreatment enhanced biomethane production. Taking into consideration both bioethanol and biomethane productions, results indicated that when using IL pretreatment, the total energy produced per kg of total solids was higher compared to untreated biomasses. Specifically energy produced from CS and SG was +18.6% and +34.5% respectively, as compared to those obtained by hot water treatment, i.e. +2.3% and +23.4% for CS and SG, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Modifying a Cow-Calf Biophysical Simulation Model for Analyses of Alternative Enterprises

    Science.gov (United States)

    Lutes, Jennifer L.

    Cow-calf producers in the United States, tasked with providing beef calves for the beef industry, have had a multitude of difficulties to overcome in recent years. Producers in northwest Arkansas were negatively impacted by high hay prices coupled with low beef cattle market prices due to severe drought experienced in portions of 2010, 2011, and 2012. During this time they also faced high grain prices, due to a record low harvest, combined with portions of the corn harvest diverted from human and animal feed to ethanol production. Tight lending policies of this time, reminiscent of the housing market crash in 2008, along with the negative public attention associated with high levels of greenhouse gas emissions associated with beef production, lead to a tough situation for cattle producers faced with increasing input costs, decreased revenue, and lack of access to loans. With these issues in mind, this research aimed to determine if incorporating switchgrass (Panicum virgatum) production on a cow-calf farm could serve to increase net returns, decrease income volatility, lower net greenhouse gas (GHG) emissions without decreasing beef output, and provide a viable source of feedstock for a potential bio-refinery. The study determined that switchgrass is a potential solution to these problems and thus aimed to discover differences in switchgrass supply under different government policies in four northwestern counties in Arkansas to an as-yet, non-existent bio-refinery. It was determined that growing switchgrass on pastureland, once devoted to cow-calf production, is a viable enterprise diversification tool that under the right conditions could be used to improve producer financial and environmental outcomes. However, bioenergy production is slow to gain traction in the US due to adverse market conditions from low fossil fuel prices. Thus, in the US, there are only a few bio-refineries currently online and accepting lignocellulosic biomass, however none of them are

  9. Produção de forragem do capim-Tanzânia (Panicum maximum Jacq. cv. Tanzânia-1 pastejado em diferentes alturas Forage production of Tanzaniagrass (Panicum maximum Jacq. cv. Tanzania-1 grazed at different heights

    Directory of Open Access Journals (Sweden)

    Clovenilson Cláudio Perissato Cano

    2004-12-01

    Full Text Available Objetivou-se, com este experimento, avaliar a massa de forragem (MF, massa de lâmina verde (MLV, massa de colmo + bainha verde (MCV, massa de material morto (MMM, massa de forragem verde (MFV, relação folha/colmo (F/C, taxa de acúmulo de massa seca (TAMS, acúmulo de massa de forragem (AMF, índice de área foliar (IAF, porcentagem de solo descoberto (SD e porcentagem de solo coberto com liteira (SCL em pastagem de capim-Tanzânia (Panicum maximum Jacq. cv. Tanzânia-1 manejada em quatro alturas do dossel forrageiro (20, 40, 60 e 80 cm. O método de pastejo utilizado foi o de lotação contínua e taxa de lotação variável, com novilhos da raça Nelore com peso médio de 340 kg. Utilizou-se o delineamento experimental inteiramente casualizado com duas repetições e realizaram-se cinco avaliações. MLV, MCV, MMM, MFV, MF, IAF, TAMS e AMF aumentaram com o avanço da altura do dossel, sendo que a porcentagem de SD, SCL e material morto diminui em pastos mais altos. O manejo do capim-Tanzânia nas alturas de 40 e 60 cm, apresentou as melhores respostas de composição morfológica, garantindo boa oferta de folhas, de cobertura do solo e taxa de acúmulo de massa seca. As alturas de 20 e 80 cm não devem ser recomendadas para o manejo do capim-Tanzânia quando o objetivo for produção com qualidade e quantidade.This experiment was conducted out to evaluate the forage mass (FM, green leaf lamina mass (GLLM, green stem + leaf sheath mass (GSSM, mass of dead material (MDM, green forage mass (GMF, total forage mass (TFM, leaf/stem ratio (L/S, dry matter accumulation rate (DMAR, leaf area index (LAI, % of bare soil (BS and litter cover percentage (LCP in Tanzaniagrass pasture (Panicum maximum Jacq. cv. Tanzania-1 managed at four different sward heights (20, 40, 60 and 80 cm. The grazing method was the continuous stocking with variable stocking rate, and the grazing animals were Nellore steers with average weight of 340 kg. The completely

  10. Efeito do hexazinone isolado e em mistura na eficiência fotossintética de Panicum maximum Effect of hexazinone applied alone and in combination on the photosynthetic efficiency of Panicum maximum

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    M. Girotto

    2012-06-01

    Full Text Available Esta pesquisa teve como objetivo avaliar a velocidade e intensidade de ação do hexazinone isolado e em mistura com outros inibidores do fotossistema II, através da eficiência fotossintética de Panicum maximum em pós-emergência. O ensaio foi constituído de seis tratamentos: hexazinone (250 g ha-1, tebuthiuron (1,0 kg ha-1, hexazinone + tebuthiuron (125 g ha-1 + 0,5 kg ha-1, diuron (2.400 g ha-1, hexazinone + diuron (125 + 1.200 g ha-1, metribuzin (1.440 g ha-1, hexazinone + metribuzin (125 + 720 g ha-1 e uma testemunha. O experimento foi instalado em delineamento inteiramente casualizado, com quatro repetições. Após a aplicação dos tratamentos, as plantas foram transportadas para casa de vegetação sob condições controladas de temperatura e umidade, onde ficaram durante o período experimental, sendo realizadas as seguintes avaliações: taxa de transporte de elétrons e análise visual de intoxicação. A avaliação com o fluorômetro foi realizada nos intervalos de 1, 2, 6, 24, 48, 72, 120 e 168 horas após a aplicação, e as avaliações visuais, aos três e sete dias após a aplicação. Os resultados demonstraram diferença nos tratamentos, enfatizando a aplicação do diuron, que reduziu lentamente o transporte de elétrons comparado com os outros herbicidas e, em mistura com hexazinone, apresentou efeito sinérgico. Verificou-se com o uso do fluorômetro a intoxicação antecipada em plantas de P. maximum após a aplicação de herbicidas inibidores do fotossistema II de forma isolada e em mistura.This work aimed to evaluate the speed and intensity of action of hexazinone applied alone and in combination with other photo-system II inhibitors on the photosynthetic efficiency of Panicum maximum in post-emergence. The assay consisted of six treatments: hexazinone (250 g ha-1, tebuthiuron (1.0 kg ha-1, hexazinone + tebuthiuron (125 g ha-1+ 0.5 kg ha-1, diuron (2,400 g ha-1, hexazinone + diuron (125 + 1,200 g ha-1, metribuzin

  11. Aislamiento e identificación de cepas de Azospirillum sp. en pasto guinea (Panicum maximum Jacq. del Valle del Cesar Isolation and identification of Azospirillum sp. in Guinea grass (Panicum maximum Jacq. of the Valle del Cesar

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    Diana M Cárdenas

    2010-09-01

    Full Text Available Se evaluó el efecto de factores ambientales del Valle del Cesar y el manejo agronómico del pasto guinea (Panicum maximum Jacq., sobre la población bacteriana del género Azospirillum en medios de cultivo semisólidos NFb y LGI, para lo cual se utilizó un diseño experimental en parcelas divididas con un arreglo factorial de 2 (épocas climáticas: lluvia y sequía x 2 (manejos agronómicos: agroecólogico y extractivo x 3 (muestras analizadas: suelo rizosférico, raíces y hojas. Los resultados no revelaron diferencias estadísticas significativas, lo que indica que esta bacteria puede mantener su población en condiciones de estrés por diferentes mecanismos fisiológicos. A partir de estas muestras se obtuvieron 16 aislamientos pertenecientes al género Azospirillum, a los cuales se les evaluó su actividad de reducción de acetileno como indicador de la fijación biológica de nitrógeno y su capacidad en la producción de compuestos indólicos como promotores del crecimiento vegetal. Se seleccionaron las cepas SRGM2, SRGM3 y SRGM4 obtenidas de muestras de suelo rizosférico de pasto guinea de la Estación Experimental Motilonia de Corpoica, municipio Agustín Codazzi, departamento del Cesar. Estos aislamientos se caracterizaron molecularmente por el gen 16S rRNA y según el análisis BLAST en la base de datos del GenBank y presentaron 93% de similitud con A. lipoferum (SRGM2 y SRGM3 y 94% con A. brasilense (SRGM4.The effect of environmental factors of the Valle del Cesar and the agronomic management of Guinea grass (Panicum maximum Jacq., on the bacterial population of the Azospirillum genus in semisolid NFb and LGI culture media was evaluated, for which an experimental design was used in divided plots with a 2 (climatic seasons: rainy and dry x 2 (agronomic managements: agroecological and extractive x 3 (analyzed samples: rhizospheric soil, roots and leaves factorial arrangement. The results did not reveal significant statistical

  12. Producción de semilla de guinea (Panicum maximum Jacq. en un sistema intensivo de ceba de ganado vacuno Seed production of Guinea grass (Panicum maximum Jacq. in an intensive cattle fattening system

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    G Oquend

    2008-09-01

    Full Text Available En un suelo Pardo sialítico del subtipo Cambisol cálcico, localizado en la Empresa Pecuaria «Calixto García», en la provincia de Holguín, se estudio la producción de semilla de guinea (Panicum maximum Jacq. en un sistema intensivo de ceba de ganado vacuno, en condiciones de riego. Los tratamientos fueron cinco varieda­des del pasto guinea: A Común; B Likoni; C Mombasa; D Tanzania; y E Tobiatá. Los siguientes métodos se consideraron a su vez como subtratamientos: 1 Siembra con semilla gámica; 2 Plantación por macollas; y 3 Por vía de trasplante. La carga se mantuvo ajustada a 2 UGM/ha. En la producción de semillas existieron interacciones favorables entre los métodos de siembra y las variedades: semilla gámica-guinea Likoni; maco­lla-guinea Mombasa, Tanzania y Tobiatá; trasplante-guinea Común. En todo el sistema de explotación se obtuvo un aporte adicional superior a los $1 000/ha por concepto de producción de semilla, sin afectar la producción animal, en la que se obtuvieron ganancias superiores a los 800 g/animal/día y producciones pro­medio de 46 212 t de carne en pie por ciclo de ceba. Se considera factible la producción de semilla del pasto guinea en sistemas intensivos de ceba de ganado vacuno.On a sialitic Brown soil of the calcic Cambisol subtype, located at the «Calixto García» Livestock Production Enterprise, in the Holguín province, the production of Guinea grass (Panicum maximum Jacq. was studied in an intensive cattle fattening system, with irrigation. The treatments were five varieties of Guinea grass: A Common; B Likoni; C Mombasa; D Tanzania; and E Tobiatá. The following methods were considered, in turn, sub-treatments: 1 Seeding with gamic seed; 2 Planting with tillers; and 3 Transplanting. The stocking rate remained adjusted at 2 animals/ha. In seed production there were favorable interactions between the planting methods and the varieties: gamic seed-Guinea grass Likoni; tiller-Guinea grass

  13. Ecological aspects study of replacement intercropping patterns of Soybean (Glycine max L. and Millet (Panicum miliaceum L.

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    Goudarz Ahmadvand

    2016-03-01

    Full Text Available Intercropping is considered for increasing and stability of yield in per unit. In order to study the effects of soybean (Glycine max L. and millet (Panicum miliaceum L. replacement intercropping on agronomic traits, diversity of weeds and soil biological activity, an experiment was conducted at the Research Station of Agricultural Faculty, of Bu-Ali Sina University, in 2014. The experiment was carried out as a randomized complete block design with three replications. The replacement intercropping series consisted of monoculture of soybean, monoculture of millet, 75% soybean+ 25% millet, 50% soybean+ 50% millet and 25% soybean+ 75% millet. The results showed that the highest seed yield of 219.8 and 171.9 gm-2 belonged to monoculture of soybean and monoculture of millet, respectively. Intercropping reduced maximum leaf area index of soybean and millet but leaf chlorophyll content of soybean and millet were increased. The highest number of pods per plant, number of seeds per plant in soybean and panicle number per plant in millet were obtained in 50S:50M ratio. Mean soil respiration rate in intercropping treatments was 4 and 8 % higher than the monoculture of soybean and millet, respectively. Intercropping patterns of 50S:50M and 25S:75M were successful in reducing weed plant density and diversity in comparison with soybean monoculture. Results showed that in all intercropping treatments, land equivalent ratio was more than one. Maximum value of land equivalent ratio (2.20 was achieved in 50S:50M treatment. Soybean and millet intercropping at different levels of replacement, didn’t have actual yield loss. Calculating the aggressivity showed that millet was more dominate than soybean. The maximum relative crowding coefficient of soybean was observed in 75S:25M, however that of millet was obtained in 25S:75M and 50S:50M intercroppings indicating that millet is more competitor than soybean.

  14. De novo assembly and characterization of the transcriptome of broomcorn millet (Panicum miliaceum L. for gene discovery and marker development

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    Hong Yue

    2016-07-01

    Full Text Available Broomcorn millet (Panicum miliaceum L. is one of the world’s oldest cultivated cereals, which is well adapted to extreme environments such as drought, heat and salinity with an efficient C4 carbon fixation. Discovery and identification of genes involved in these processes will provide valuable information to improve the crop for meeting the challenge of global climate change. However, the lack of genetic resources and genomic information make gene discovery and molecular mechanism studies very difficult. Here, we sequenced and assembled the transcriptome of broomcorn millet using Illumina sequencing technology. After sequencing, a total of 45,406,730 and 51,160,820 clean paired-end reads were obtained for two genotypes Yumi No.2 and Yumi No.3. These reads were mixed and then assembled into 113,643 unigenes, with the length ranging from 351 to 15,691 bp, of which 62,543 contings could be assigned to 315 gene ontology (GO categories. Cluster of orthologous groups and kyoto encyclopedia of genes and genomes (KEGG analyses assigned could map 15,514 unigenes into 202 KEGG pathways and 51,020 unigenes to 25 COG categories, respectively. Furthermore, 35,216 simple sequence repeats (SSRs were identified in 27,055 unigene sequences, of which trinucleotides were the most abundant repeat unit, accounting for 66.72% of SSRs. In addition, 292 differentially expressed genes (DEGs were identified between the two genotypes, which were significantly enriched in 88 GO terms and 12 KEGG pathways. Finally, the expression patterns of 4 selected transcripts were validated through quantitative reverse transcription PCR (qRT-PCR analysis. Our study for the first time sequenced and assembled the transcriptome of broomcorn millet, which not only provided a rich sequence resource for gene discovery and marker development in this important crop, but will also facilitate the further investigation of the molecular mechanism of its favored agronomic traits and beyond.

  15. Perennial species for optimum production of herbaceous biomass in the Piedmont (Management study, 1987--1991)

    Energy Technology Data Exchange (ETDEWEB)

    Parrish, D.J.; Wolf, D.D.; Daniels, W.L. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Crop and Soil Environmental Sciences)

    1993-04-01

    The authors have investigated cutting and N management strategies for two biofuel feedstock candidate species -- switchgrass (Panicum virgatum) and weeping lovegrass (Eragrostis curvula). Each was no-till planted in 1987 at three sites underlain by Davidson or Cecil soils. Three N levels (0, 50, or 100 kg/ha) were applied, and the plots fertilized at each level were harvested either twice (early-September and early-November) or only in early-November. The results with lovegrass suggest 50 kg N/ha is nearly optimal and that two cuttings provide more biomass than one. For switchgrass, when averaged across sites and years, 50 kg N/ha produced a slight yield advantage over no added N, but 50 kg was not different from 100 kg. In 1989 and 1990, more biomass was available in early-September harvests (9.6 Mg/ha) than in early-November (8.3 Mg/ha). Apparently the plants translocated significant portions of their biomass below ground during the last few weeks of the season. In 1991, we harvested only in early-November. Plots that had been cut in early-September in the previous three years had lower yields (7.6 Mg/ha) than those that had been cut only in early-November (9.4 Mg/ha). The delayed cutting permitted more growth on a sustained basis -- presumably because of conservation of translocatable materials. This poses an interesting dilemma for the producer of biomass. In additional studies, the authors found no advantage in double-cropping rye (Secale cereale) with switchgrass; at low input levels, rye yields were low, and rye lowered switchgrass yields. Other studies showed double-cropping with winter-annual legumes such as crimson clover (Trifolium incarnatum) may have potential. The timing of herbicide treatment of the legume is critical.

  16. Perennial species for optimum production of herbaceous biomass in the Piedmont (Management study, 1987--1991). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Parrish, D.J.; Wolf, D.D.; Daniels, W.L. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (US). Dept. of Crop and Soil Environmental Sciences

    1993-04-01

    The authors have investigated cutting and N management strategies for two biofuel feedstock candidate species -- switchgrass (Panicum virgatum) and weeping lovegrass (Eragrostis curvula). Each was no-till planted in 1987 at three sites underlain by Davidson or Cecil soils. Three N levels (0, 50, or 100 kg/ha) were applied, and the plots fertilized at each level were harvested either twice (early-September and early-November) or only in early-November. The results with lovegrass suggest 50 kg N/ha is nearly optimal and that two cuttings provide more biomass than one. For switchgrass, when averaged across sites and years, 50 kg N/ha produced a slight yield advantage over no added N, but 50 kg was not different from 100 kg. In 1989 and 1990, more biomass was available in early-September harvests (9.6 Mg/ha) than in early-November (8.3 Mg/ha). Apparently the plants translocated significant portions of their biomass below ground during the last few weeks of the season. In 1991, we harvested only in early-November. Plots that had been cut in early-September in the previous three years had lower yields (7.6 Mg/ha) than those that had been cut only in early-November (9.4 Mg/ha). The delayed cutting permitted more growth on a sustained basis -- presumably because of conservation of translocatable materials. This poses an interesting dilemma for the producer of biomass. In additional studies, the authors found no advantage in double-cropping rye (Secale cereale) with switchgrass; at low input levels, rye yields were low, and rye lowered switchgrass yields. Other studies showed double-cropping with winter-annual legumes such as crimson clover (Trifolium incarnatum) may have potential. The timing of herbicide treatment of the legume is critical.

  17. The feasibility of producing adequate feedstock for year–round cellulosic ethanol production in an intensive agricultural fuelshed

    Science.gov (United States)

    Uden, Daniel R.; Mitchell, Rob B.; Allen, Craig R.; Guan, Qingfeng; McCoy, Tim D.

    2013-01-01

    To date, cellulosic ethanol production has not been commercialized in the United States. However, government mandates aimed at increasing second-generation biofuel production could spur exploratory development in the cellulosic ethanol industry. We conducted an in-depth analysis of the fuelshed surrounding a starch-based ethanol plant near York, Nebraska that has the potential for cellulosic ethanol production. To assess the feasibility of supplying adequate biomass for year-round cellulosic ethanol production from residual maize (Zea mays) stover and bioenergy switchgrass (Panicum virgatum) within a 40-km road network service area of the existing ethanol plant, we identified ∼14,000 ha of marginally productive cropland within the service area suitable for conversion from annual rowcrops to switchgrass and ∼132,000 ha of maize-enrolled cropland from which maize stover could be collected. Annual maize stover and switchgrass biomass supplies within the 40-km service area could range between 429,000 and 752,000 metric tons (mT). Approximately 140–250 million liters (l) of cellulosic ethanol could be produced, rivaling the current 208 million l annual starch-based ethanol production capacity of the plant. We conclude that sufficient quantities of biomass could be produced from maize stover and switchgrass near the plant to support year-round cellulosic ethanol production at current feedstock yields, sustainable removal rates and bioconversion efficiencies. Modifying existing starch-based ethanol plants in intensive agricultural fuelsheds could increase ethanol output, return marginally productive cropland to perennial vegetation, and remove maize stover from productive cropland to meet feedstock demand.

  18. Opportunities for Energy Crop Production Based on Subfield Scale Distribution of Profitability

    Directory of Open Access Journals (Sweden)

    Ian J. Bonner

    2014-10-01

    Full Text Available Incorporation of dedicated herbaceous energy crops into row crop landscapes is a promising means to supply an expanding biofuel industry while benefiting soil and water quality and increasing biodiversity. Despite these positive traits, energy crops remain largely unaccepted due to concerns over their practicality and cost of implementation. This paper presents a case study for Hardin County, Iowa, to demonstrate how subfield decision making can be used to target candidate areas for conversion to energy crop production. Estimates of variability in row crop production at a subfield level are used to model the economic performance of corn (Zea mays L. grain and the environmental impacts of corn stover collection using the Landscape Environmental Analysis Framework (LEAF. The strategy used in the case study integrates switchgrass (Panicum virgatum L. into subfield landscape positions where corn grain is modeled to return a net economic loss. Results show that switchgrass integration has the potential to increase sustainable biomass production from 48% to 99% (depending on the rigor of conservation practices applied to corn stover collection, while also improving field level profitability of corn. Candidate land area is highly sensitive to grain price (0.18 to 0.26 $·kg−1 and dependent on the acceptable subfield net loss for corn production (ranging from 0 to −1000 $·ha−1 and the ability of switchgrass production to meet or exceed this return. This work presents the case that switchgrass may be economically incorporated into row crop landscapes when management decisions are applied at a subfield scale within field areas modeled to have a negative net profit with current management practices.

  19. Impacts of biofuels production alternatives on water quantity and quality in the Iowa River Basin

    Science.gov (United States)

    Wu, Y.; Liu, S.

    2012-01-01

    Corn stover as well as perennial grasses like switchgrass (Panicum virgatum) and miscanthus are being considered as candidates for the second generation biofuel feedstocks. However, the challenges to biofuel development are its effects on the environment, especially water quality. This study evaluates the long-term impacts of biofuel production alternatives (e.g., elevated corn stover removal rates and the potential land cover change) on an ecosystem with a focus on biomass production, soil erosion, water quantity and quality, and soil nitrate nitrogen concentration at the watershed scale. The Soil and Water Assessment Tool (SWAT) was modified for setting land cover change scenarios and applied to the Iowa River Basin (a tributary of the Upper Mississippi River Basin). Results show that biomass production can be sustained with an increased stover removal rate as long as the crop demand for nutrients is met with appropriate fertilization. Although a drastic increase (4.7–70.6%) in sediment yield due to erosion and a slight decrease (1.2–3.2%) in water yield were estimated with the stover removal rate ranging between 40% and 100%, the nitrate nitrogen load declined about 6–10.1%. In comparison to growing corn, growing either switchgrass or miscanthus can reduce sediment erosion greatly. However, land cover changes from native grass to switchgrass or miscanthus would lead to a decrease in water yield and an increase in nitrate nitrogen load. In contrast to growing switchgrass, growing miscanthus is more productive in generating biomass, but its higher water demand may reduce water availability in the study area.

  20. Can the Results of Biodiversity-Ecosystem Productivity Studies Be Translated to Bioenergy Production?

    Directory of Open Access Journals (Sweden)

    Timothy L Dickson

    Full Text Available Biodiversity experiments show that increases in plant diversity can lead to greater biomass production, and some researchers suggest that high diversity plantings should be used for bioenergy production. However, many methods used in past biodiversity experiments are impractical for bioenergy plantings. For example, biodiversity experiments often use intensive management such as hand weeding to maintain low diversity plantings and exclude unplanted species, but this would not be done for bioenergy plantings. Also, biodiversity experiments generally use high seeding densities that would be too expensive for bioenergy plantings. Here we report the effects of biodiversity on biomass production from two studies of more realistic bioenergy crop plantings in southern Michigan, USA. One study involved comparing production between switchgrass (Panicum virgatum monocultures and species-rich prairie plantings on private farm fields that were managed similarly to bioenergy plantings. The other study was an experiment where switchgrass was planted in monoculture and in combination with increasingly species-rich native prairie mixtures. Overall, we found that bioenergy plantings with higher species richness did not produce more biomass than switchgrass monocultures. The lack of a positive relationship between planted species richness and production in our studies may be due to several factors. Non-planted species (weeds were not removed from our studies and these non-planted species may have competed with planted species and also prevented realized species richness from equaling planted species richness. Also, we found that low seeding density of individual species limited the biomass production of these individual species. Production in future bioenergy plantings with high species richness may be increased by using a high density of inexpensive seed from switchgrass and other highly productive species, and future efforts to translate the results of

  1. Production of butanol (a biofuel) from agricultural residues: Part II - Use of corn stover and switchgrass hydrolysates

    Energy Technology Data Exchange (ETDEWEB)

    Qureshi, Nasib; Saha, Badal C.; Hector, Ronald E.; Dien, Bruce; Iten, Loren; Bowman, Michael J.; Cotta, Michael A. [United States Department of Agriculture (USDA), Agricultural Research Service (ARS), National Center for Agricultural Utilization Research (NCAUR), Bioenergy Research, 1815 N. University Street, Peoria, IL 61604 (United States); Hughes, Stephen; Liu, Siqing [USDA-ARS-NCAUR, Renewable Product Technology, 1815 N. University Street, Peoria, IL 61604 (United States); Sarath, Gautam [USDA-ARS, Grain, Forage, and Bioenergy Research Unit, University of Nebraska, 314 Biochemistry Hall, East Campus, Lincoln, NE 68583 (United States)

    2010-04-15

    Acetone butanol ethanol (ABE) was produced from hydrolysed corn stover and switchgrass using Clostridium beijerinckii P260. A control experiment using glucose resulted in the production of 21.06 g L{sup -1} total ABE. In this experiment an ABE yield and productivity of 0.41 and 0.31 g L{sup -1} h{sup -1} was achieved, respectively. Fermentation of untreated corn stover hydrolysate (CSH) exhibited no growth and no ABE production; however, upon dilution with water (two fold) and wheat straw hydrolysate (WSH, ratio 1:1), 16.00 and 18.04 g L{sup -1} ABE was produced, respectively. These experiments resulted in ABE productivity of 0.17-0.21 g L{sup -1} h{sup -1}. Inhibitors present in CSH were removed by treating the hydrolysate with Ca(OH){sub 2} (overliming). The culture was able to produce 26.27 g L{sup -1} ABE after inhibitor removal. Untreated switchgrass hydrolysate (SGH) was poorly fermented and the culture did not produce more than 1.48 g L{sup -1} ABE which was improved to 14.61 g L{sup -1}. It is suggested that biomass pretreatment methods that do not generate inhibitors be investigated. Alternately, cultures resistant to inhibitors and able to produce butanol at high concentrations may be another approach to improve the current process. (author)

  2. Characteristics of Lignin Fractions from Dilute Acid Pretreated Switchgrass and Their Effect on Cellobiohydrolase from Trichoderma longibrachiatum

    Directory of Open Access Journals (Sweden)

    Lan Yao

    2018-02-01

    Full Text Available To investigate the interactions between acid pretreated switchgrass lignin and cellobiohydrolase (CBH, three different lignin fractions were isolated from dilute acid pretreated switchgrass by (i ethanol extraction, followed by (ii dioxane/H2O extraction, and (iii cellulase treatment, respectively. Structural properties of each lignin fraction were elucidated by GPC, 13C-NMR, and 2D-HSQC NMR analyses. The adsorptions of CBH to the isolated lignin fractions were also studied by Langmuir adsorption isotherms. Ethanol-extractable lignin fraction, mainly composed of syringyl (S and guaiacyl (G units, had the lowest molecular weight, while dioxane/H2O-extracted lignin fraction had the lowest S/G ratio with higher content of p-coumaric acid (pCA unit. The residual lignin fraction after enzymatic treatment had the highest S/G ratio without hydroxyphenyl (H unit. Strong associations were found between lignin properties such as lignin composition and S/G ratio and its non-productive enzyme adsorption factors including the maximum adsorption capacity and binding strength.

  3. Natural binders and solid bridge type binding mechanisms in briquettes and pellets made from corn stover and switchgrass.

    Science.gov (United States)

    Kaliyan, Nalladurai; Morey, R Vance

    2010-02-01

    Corn stover and switchgrass are two important feedstocks considered for producing renewable fuels and energy in the US. Densification of these biomass feedstocks into briquettes/pellets would help reduce the problems and costs of bulk transportation, handling, and storage of biomass feedstocks. In this study, the role of the natural binders in corn stover and switchgrass to make durable particle-particle bonding in briquettes/pellets was investigated by micro-structural analyses. Scanning Electron Microscopy (SEM) images of briquettes made by using a uniaxial piston-cylinder densification apparatus in the laboratory, briquettes made by using a pilot-scale roll-press briquetting machine, and pellets made by using a pilot-scale conventional ring-die pelleting machine were analysed. The SEM images showed that the bonding between particles was created mainly through solid bridges. The solid bridges between particles were made by natural binders in the biomass expressed during the densification process. UV auto-fluorescence images of briquettes and pellets further confirmed that the solid bridges were made mainly by natural binders such as lignin and protein. It was found that activating (softening) the natural binders using moisture and temperature in the range of glass transition is important to make durable particle-particle bonding.

  4. Comparison of woody pellets, straw pellets, and delayed harvest system herbaceous biomass (switchgrass and miscanthus): analysis of current combustion techniques determining the value of biomass

    NARCIS (Netherlands)

    Hui, Y.

    2011-01-01

    Since the energy consumption is growing fast, it is important to find alternative resources for the future generation energy supply. This study is going to compare the woody pellets, straw pellets and delayed harvest system biomass (switchgrass and miscanthus) from the combustion technique

  5. Large-scale bioenergy production from soybeans and switchgrass in Argentina: Part A: Potential and economic feasibility for national and international markets

    NARCIS (Netherlands)

    van Dam, J.; Faaij, A.P.C.; Hilbert, J.; Petruzzi, H.; Turkenburg, W.C.

    2009-01-01

    This study focuses on the economic feasibility for large-scale biomass production from soybeans or switchgrass from a region in Argentina. This is determined, firstly, by estimating whether the potential supply of biomass, when food and feed demand are met, is sufficient under different scenarios to

  6. Temporal dynamics of fibrolytic and methanogenic rumen microorganisms during in situ incubation of switchgrass determined by 16S rRNA gene profiling

    Directory of Open Access Journals (Sweden)

    Hailan ePiao

    2014-07-01

    Full Text Available The rumen is known for its biomass-degrading and methane-producing phenotype. Fermentation of recalcitrant plant material necessitates the synergistic activity of diverse microbial taxonomic groups that inhabit this anaerobic environment. Although interspecies hydrogen (H2 transfer, a process during which bacterially generated H2 is transferred to methanogenic Archaea, has obtained significant attention over the last decades, the temporal variation of the different taxa involved in in situ biomass-degradation, H2 transfer and methanogenesis process remains to be established. We investigated the temporal succession of microbial taxa and its effect on fiber composition during rumen incubation using 16S rRNA amplicon sequencing. Switchgrass filled nylon bags were placed in the rumen of a cannulated cow and collected at nine time points for DNA extraction and 16S pyrotag profiling. The microbial community colonizing the air-dried and non-incubated switchgrass was dominated by members of the Bacilli. During in situ incubation of the switchgrass, two major shifts in the community composition were observed: Bacilli were replaced within 30 min by members belonging to the Bacteroidia and Clostridia. A second significant shift was observed after 16 h of rumen incubation, when members of the Spirochaetes and Fibrobacteria classes became more abundant in the fiber-adherent community. During the first 30 min of rumen incubation ~13% of the switchgrass dry matter was degraded, whereas little biomass degradation appeared to have occurred between 30 min and 4 h after the switchgrass was placed in the rumen. Interestingly, methanogenic members of the Euryarchaeota increased up to 3-fold during this period of reduced biomass-degradation, with peak abundance just before rates of dry matter degradation increased again. We hypothesize that during this period microbial-mediated fibrolysis was temporarily inhibited until H2 was metabolized into CH4 by methanogens.

  7. Fermentation characteristics and nutritive value of low moisture ...

    African Journals Online (AJOL)

    Fermentation characteristics and nutritive value of low moisture silage made from mature bermudagrass ( C. dactylon ) and switchgrass ( P. virgatum ) in mixture with alfalfa ( M. sativa ) or treated with urea and plantain ( Musa AAB )

  8. Comportamiento de 19 accesiones de Panicum maximum Jacq. bajo condiciones de pastoreo en un suelo de mediana fertilidad

    Directory of Open Access Journals (Sweden)

    R Machado

    Full Text Available El objetivo de este trabajo fue determinar el comportamiento de 19 accesiones de Panicum maximum en suelos de mediana fertilidad. Se utilizó un diseño de bloques al azar con tres repeticiones y parcelas de 20 m². Las rotaciones (pastoreo racional simulado se efectuaron entre 60 y 70 días (época de seca y entre 32 y 40 días (época de lluvia. Se detectó una aceptable variabilidad entre tratamientos (70,7 %. Los indicadores más variables fueron: la disponibilidad, el porcentaje de utilización, el porcentaje de hojas y la altura de las plantas. Se aplicó un análisis de conglomerados y se formaron dos grupos: tipos gigantes (grupo 1 y tipos medianos (grupo 2. Los tratamientos del grupo 1 alcanzaron una disponibilidad media de 5,0 t MS/ha/rotación y superaron en 0,7 t MS/ha/rotación a los del grupo 2. Sin embargo, estos últimos mostraron menores síntomas de clorosis (34,0 %, fueron más tolerantes a los microorganismos patógenos (25,0 % y menos afectados por la sequía (42,0 %, y presentaron mayor vigor (3,8 como media de los tres años. Se concluye que en la variabilidad tuvieron un papel fundamental la disponibilidad, la altura, el porcentaje de hojas y el porcentaje de utilización. El resto de los indicadores fue relativamente poco variable, pero también permitió enjuiciar el comportamiento de estos materiales. Se recomiendan los tipos medianos CIH-6, SIH-810 y CIH-22 como variedades precomerciales para condiciones similares a las aquí utilizadas, e incluir el tipo gigante SIH-759 en ensayos en los que se emplee el corte o el pastoreo con mayor intensidad

  9. Restoration of soil organic carbon with cultivation of perennial biofuel crops

    Science.gov (United States)

    Davis, S. C.; Yannarell, A.; Masters, M.; Anderson-Teixeira, K.; Drake, J. E.; Darmody, R.; Mackie, R.; David, M.; Delucia, E. H.

    2009-12-01

    A biofuel crop that can restore soil quality and maximize terrestrial carbon (C) sequestration would add substantial value to the sustainability of biofuel production chains. Currently in the Midwestern USA, Zea mays is the dominant biofuel feedstock despite a history of soil degradation associated with this crop. We compared soil organic carbon (SOC) storage and microbial communities in Zea mays L. (corn), Panicum virgatum L. (switchgrass), Miscanthus x giganteus Greef et Deuter (miscanthus), and native prairie sites at seven locations that spanned a range of temperatures, precipitation, and soil types in Illinois, USA. By comparing annually harvested switchgrass and miscanthus plots to conventional corn agro-ecosystems and native prairies, we determined the SOC restoration potential of perennial biofuel crops. We also calculated SOC accumulation using the δ13C isotope composition of the soil as a tracer for C4 plant-derived SOC additions. SOC differences among plant species varied significantly among sites, but on average, seven-year-old plots of miscanthus and switchgrass had 73% and 57% greater SOC in the top meter of soil than conventional corn crops, respectively, and had 50-63% greater SOC than the younger (four-year-old) miscanthus and switchgrass plots. The δ13C isotope signature of soil in miscanthus and switchgrass plots also indicated an accumulation of SOC. Plant species and SOC variability among sites explained 40-62% of the variation in microbial communities across sites. Microbial communities associated with annually harvested switchgrass and miscanthus differ from communities found in conventional corn agriculture and prairies. Thus, the potential to restore SOC to agriculturally depleted soils of the Midwest is not dependent on a soil microbial community that mimics prairie soil communities. Planting perennial grasses as biofuel crops can lead to an increase in SOC and a change in soil microbial communities. Conventional agricultural soils might

  10. Direct measures of mechanical energy for knife mill size reduction

    Energy Technology Data Exchange (ETDEWEB)

    Bitra, V.S.P. [University of Tennessee; Womac, A.R. [University of Tennessee; Igathinathane, C. [Mississippi State University (MSU); Miu, P.I [University of Tennessee; Yang, Y.T. [University of Tennessee; Smith, D.R. [University of Tennessee; Chevanan, Nehru [University of Tennessee; Sokhansanj, Shahabaddine [ORNL

    2009-08-01

    Lengthy straw/stalk of biomass may not be directly fed into grinders such as hammer mills and disc refiners. Hence, biomass needs to be preprocessed using coarse grinders like a knife mill to allow for efficient feeding in refiner mills without bridging and choking. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented knife mill. Direct power inputs were determined for different knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. Overall accuracy of power measurement was calculated to be 0.003 kW. Total specific energy (kWh/Mg) was defined as size reduction energy to operate mill with biomass. Effective specific energy was defined as the energy that can be assumed to reach the biomass. The difference is parasitic or no-load energy of mill. Total specific energy for switchgrass, wheat straw, and corn stover chopping increased with knife mill speed, whereas, effective specific energy decreased marginally for switchgrass and increased for wheat straw and corn stover. Total and effective specific energy decreased with an increase in screen size for all the crops studied. Total specific energy decreased with increase in mass feed rate, but effective specific energy increased for switchgrass and wheat straw, and decreased for corn stover at increased feed rate. For knife mill screen size of 25.4 mm and optimum speed of 250 rpm, optimum feed rates were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively, and the corresponding total specific energies were 7.57, 10.53, and 8.87 kWh/Mg and effective specific energies were 1.27, 1.50, and 0.24 kWh/Mg for switchgrass, wheat straw, and corn stover, respectively. Energy utilization ratios were calculated as 16.8%, 14.3%, and 2.8% for switchgrass, wheat straw, and corn stover, respectively. These

  11. Mapping grasslands suitable for cellulosic biofuels in the Greater Platte River Basin, United States

    Science.gov (United States)

    Wylie, Bruce K.; Gu, Yingxin

    2012-01-01

    Biofuels are an important component in the development of alternative energy supplies, which is needed to achieve national energy independence and security in the United States. The most common biofuel product today in the United States is corn-based ethanol; however, its development is limited because of concerns about global food shortages, livestock and food price increases, and water demand increases for irrigation and ethanol production. Corn-based ethanol also potentially contributes to soil erosion, and pesticides and fertilizers affect water quality. Studies indicate that future potential production of cellulosic ethanol is likely to be much greater than grain- or starch-based ethanol. As a result, economics and policy incentives could, in the near future, encourage expansion of cellulosic biofuels production from grasses, forest woody biomass, and agricultural and municipal wastes. If production expands, cultivation of cellulosic feedstock crops, such as switchgrass (Panicum virgatum L.) and miscanthus (Miscanthus species), is expected to increase dramatically. The main objective of this study is to identify grasslands in the Great Plains that are potentially suitable for cellulosic feedstock (such as switchgrass) production. Producing ethanol from noncropland holdings (such as grassland) will minimize the effects of biofuel developments on global food supplies. Our pilot study area is the Greater Platte River Basin, which includes a broad range of plant productivity from semiarid grasslands in the west to the fertile corn belt in the east. The Greater Platte River Basin was the subject of related U.S. Geological Survey (USGS) integrated research projects.

  12. The miR156-SPL4 module predominantly regulates aerial axillary bud formation and controls shoot architecture.

    Science.gov (United States)

    Gou, Jiqing; Fu, Chunxiang; Liu, Sijia; Tang, Chaorong; Debnath, Smriti; Flanagan, Amy; Ge, Yaxin; Tang, Yuhong; Jiang, Qingzhen; Larson, Preston R; Wen, Jiangqi; Wang, Zeng-Yu

    2017-11-01

    Grasses possess basal and aerial axillary buds. Previous studies have largely focused on basal bud (tiller) formation but scarcely touched on aerial buds, which may lead to aerial branch development. Genotypes with and without aerial buds were identified in switchgrass (Panicum virgatum), a dedicated bioenergy crop. Bud development was characterized using scanning electron microscopy. Microarray, RNA-seq and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to identify regulators of bud formation. Gene function was characterized by down-regulation and overexpression. Overexpression of miR156 induced aerial bud formation in switchgrass. Various analyses revealed that SQUAMOSA PROMOTER BINDING PROTEIN LIKE4 (SPL4), one of the miR156 targets, directly regulated aerial axillary bud initiation. Down-regulation of SPL4 promoted aerial bud formation and increased basal buds, while overexpression of SPL4 seriously suppressed bud formation and tillering. RNA-seq and RT-qPCR identified potential downstream genes of SPL4. Unlike all previously reported genes acting as activators of basal bud initiation, SPL4 acts as a suppressor for the formation of both aerial and basal buds. The miR156-SPL4 module predominantly regulates aerial bud initiation and partially controls basal bud formation. Genetic manipulation of SPL4 led to altered plant architecture with increased branching, enhanced regrowth after cutting and improved biomass yield. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  13. Improving Bioenergy Crops through Dynamic Metabolic Modeling

    Directory of Open Access Journals (Sweden)

    Mojdeh Faraji

    2017-10-01

    Full Text Available Enormous advances in genetics and metabolic engineering have made it possible, in principle, to create new plants and crops with improved yield through targeted molecular alterations. However, while the potential is beyond doubt, the actual implementation of envisioned new strains is often difficult, due to the diverse and complex nature of plants. Indeed, the intrinsic complexity of plants makes intuitive predictions difficult and often unreliable. The hope for overcoming this challenge is that methods of data mining and computational systems biology may become powerful enough that they could serve as beneficial tools for guiding future experimentation. In the first part of this article, we review the complexities of plants, as well as some of the mathematical and computational methods that have been used in the recent past to deepen our understanding of crops and their potential yield improvements. In the second part, we present a specific case study that indicates how robust models may be employed for crop improvements. This case study focuses on the biosynthesis of lignin in switchgrass (Panicum virgatum. Switchgrass is considered one of the most promising candidates for the second generation of bioenergy production, which does not use edible plant parts. Lignin is important in this context, because it impedes the use of cellulose in such inedible plant materials. The dynamic model offers a platform for investigating the pathway behavior in transgenic lines. In particular, it allows predictions of lignin content and composition in numerous genetic perturbation scenarios.

  14. Modeling Phosphorus Capture by Plants Growing in a Multispecies Riparian Buffer

    Directory of Open Access Journals (Sweden)

    J. M. Kelly

    2012-01-01

    Full Text Available The NST 3.0 mechanistic nutrient uptake model was used to explore P uptake to a depth of 120 cm over a 126 d growing season in simulated buffer communities composed of mixtures of cottonwood (Populus deltoids Bartr., switchgrass (Panicum virgatum L., and smooth brome (Bromus inermis Leyss. Model estimates of P uptake from pure stands of smooth brome and cottonwood were 18.9 and 24.5 kg ha−1, respectively. Uptake estimates for mixed stands of trees and grasses were intermediate to pure stands. A single factor sensitivity analysis of parameters used to calculate P uptake for each cover type indicated that Imax, k, ro, and Lo were consistently the most responsive to changes ranging from −50% to +100%. Model exploration of P uptake as a function of soil depth interval indicated that uptake was highest in the 0–30 cm intervals, with values ranging from 85% of total for cottonwood to 56% for switchgrass.

  15. Bioremediation and phytoremediation of total petroleum hydrocarbons (TPH) under various conditions.

    Science.gov (United States)

    McIntosh, Patrick; Schulthess, Cristian P; Kuzovkina, Yulia A; Guillard, Karl

    2017-08-03

    Remediation of contaminated soils is often studied using fine-textured soils rather than low-fertility sandy soils, and few studies focus on recontamination events. This study compared aerobic and anaerobic treatments for remediation of freshly introduced used motor oil on a sandy soil previously phytoremediated and bioacclimated (microorganisms already adapted in the soil environment) with some residual total petroleum hydrocarbon (TPH) contamination. Vegetated and unvegetated conditions to remediate anthropogenic fill containing residual TPH that was spiked with nonaqueous phase liquids (NAPLs) were evaluated in a 90-day greenhouse pot study. Vegetated treatments used switchgrass (Panicum virgatum). The concentration of aerobic bacteria were orders of magnitude higher in vegetated treatments compared to unvegetated. Nevertheless, final TPH concentrations were low in all saturated soil treatments, and high in the presence of switchgrass. Concentrations were also low in unvegetated pots with fertilizer. Acclimated indigenous microbial communities were shown to be more effective in breaking down hydrocarbons than introducing microbes from the addition of plant treatments in sandy soils. Remediation of fresh introduced NAPLs on pre-phytoremediated and bioacclimated soil was most efficient in saturated, anaerobic environments, probably due to the already pre-established microbial associations, easily bioavailable contaminants, and optimized soil conditions for microbial establishment and survival.

  16. Comparative feedstock analysis in Setaria viridis L. as a model for C4 bioenergy grasses and Panicoid crop species

    Directory of Open Access Journals (Sweden)

    Carloalberto ePetti

    2013-06-01

    Full Text Available Second generation feedstocks for bioethanol will likely include a sizable proportion of perennial C4 grasses, principally in the Panicoideae clade. The Panicoideae contain agronomically important annual grasses including Zea mays L. (maize, Sorghum bicolor (L. Moench (sorghum, and Saccharum officinarum L. (sugar cane as well as promising second generation perennial feedstocks including Miscanthus x giganteus and Panicum virgatum L. (switchgrass. The underlying complexity of these polyploid grass genomes is a major limitation for their direct manipulation and thus driving a need for rapidly cycling comparative model. Setaria viridis (green millet is a rapid cycling C4 Panicoid grass with a relatively small and sequenced diploid genome and abundant seed production. Stable, transient and protoplast transformation technologies have also been developed for S. viridis making it a potentially excellent model for other C4 bioenergy grasses. Here, the lignocellulosic feedstock composition, cellulose biosynthesis inhibitor (CBI response and saccharification dynamics of S. viridis are compared with the annual s00orghum and maize and the perennial switchgrass bioenergy crops as a baseline study into the applicability for translational research. A genome-wide systematic investigation of the cellulose synthase-A (CesA genes was performed identifying eight candidate sequences. Two-developmental stages; a metabolically active young tissue and b metabolically plateaued (mature material are examined to compare biomass performance metrics.

  17. Détermination de la cellulose, des hémicelluloses, de la lignine et des cendres dans diverses cultures lignocellulosiques dédiées à la production de bioéthanol de deuxième génération

    Directory of Open Access Journals (Sweden)

    Godin, B.

    2010-01-01

    Full Text Available Cellulose, hemicelluloses, lignin, and ash contents in various lignocellulosic crops for second generation bioethanol production. Various green energy crops are available for the production of renewable energy vectors such as second generation bioethanol. The efficiency of the energy recovery potential of these lignocellulosic crops depends on the crop husbandry, their content of main components (cellulose, hemicelluloses, lignin, ash and on the second generation bioethanol production process. The lignocellulosic crops investigated in this study are miscanthus (Miscanthus x giganteus J.M.Greef & Deuter ex Hodk. & Renvoize, switchgrass (Panicum virgatum L., fescue (Festuca arundinacea Schreb., fiber sorghum (Sorghum bicolor (L. Moench, fiber corn (Zea mays L., "cocksfoot-alfalfa" mixture (Dactylis glomerata L. – Medicago sativa L., comfrey (Symphytum officinale L., jerusalem artichoke (aerial part (Helianthus tuberosus L. and hemp (Cannabis sativa L.. The samples came from different energy crop trials and their content in cellulose, hemicelluloses and lignin was quantified using the Van Soest method. The ash content has also been quantified. The lignocellulosic crops with the best theoretical potential to produce second generation bioethanol based on their biochemical composition (with a yield of 100% for the hydrolysis and the fermentation of cellulose and hemicelluloses are in decreasing order miscanthus, switchgrass, fescue, fiber sorghum, fiber corn and hemp. On one hand, these crops are composed of high amounts of cellulose and hemicelluloses and, on the other hand, the lignin and ash concentration are low. A principal component analysis showed that commeniloïd monocotyledonous and dicotyledonous lignocellulosic crops formed two differentiated categories.

  18. Ethanol and High-Value Terpene Co-Production from Lignocellulosic Biomass of Cymbopogon flexuosus and Cymbopogon martinii.

    Directory of Open Access Journals (Sweden)

    Blake L Joyce

    Full Text Available Cymbopogon flexuosus, lemongrass, and C. martinii, palmarosa, are perennial grasses grown to produce essential oils for the fragrance industry. The objectives of this study were (1 to evaluate biomass and oil yields as a function of nitrogen and sulfur fertilization, and (2 to characterize their utility for lignocellulosic ethanol compared to Panicum virgatum (switchgrass. Mean biomass yields were 12.83 Mg lemongrass ha-1 and 15.11 Mg palmarosa ha-1 during the second harvest year resulting in theoretical biofuel yields of 2541 and 2569 L ethanol ha-1 respectively compared to reported 1749-3691 L ethanol ha-1 for switchgrass. Pretreated lemongrass yielded 198 mL ethanol (g biomass-1 and pretreated palmarosa yielded 170 mL ethanol (g biomass-1. Additionally, lemongrass yielded 85.7 kg essential oil ha-1 and palmarosa yielded 67.0 kg ha-1 with an estimated value of USD $857 and $1005 ha-1. These data suggest that dual-use crops such as lemongrass and palmarosa may increase the economic viability of lignocellulosic biofuels.

  19. Seasonality and Management Affect Land Surface Temperature Differences Between Loblolly Pine and Switchgrass Ecosystems in Central Virginia

    Science.gov (United States)

    Ahlswede, B.; Thomas, R. Q.; O'Halloran, T. L.; Rady, J.; LeMoine, J.

    2017-12-01

    Changes in land-use and land management can have biogeochemical and biophysical effects on local and global climate. While managed ecosystems provide known food and fiber benefits, their influence on climate is less well quantified. In the southeastern United States, there are numerous types of intensely managed ecosystems but pine plantations and switchgrass fields represent two biogeochemical and biophysical extremes; a tall, low albedo forest with trees harvested after multiple decades vs. a short, higher albedo C4 grass field that is harvested annually. Despite the wide spread use of these ecosystems for timber and bioenergy, a quantitative, empirical evaluation of the net influence of these ecosystems on climate is lacking because it requires measuring both the greenhouse gas and energy balance of the ecosystems while controlling for the background weather and soil environment. To address this need, we established a pair of eddy flux towers in these ecosystems that are co-located (1.5 km apart) in Central Virginia and measured the radiative energy, non-radiative energy and carbon fluxes, along with associated biometeorology variables; the paired site has run since April 2016. During the first 1.5 years (two growing seasons), we found strong seasonality in the difference in surface temperature between the two ecosystems. In the growing seasons, both sites had similar surface temperature despite higher net radiation in pine. Following harvest of the switchgrass in September, the switchgrass temperatures increased relative to pine. In the winter, the pine ecosystem was warmer. We evaluate the drivers of these intra-annual dynamics and compare the climate influence of these biophysical differences to the differences in carbon fluxes between the sites using a suite of established climate regulation services metrics. Overall, our results show tradeoffs exist between the biogeochemical and biophysical climate services in managed ecosystems in the southeastern United

  20. Impact of pretreated Switchgrass and biomass carbohydrates on Clostridium thermocellum ATCC 27405 cellulosome composition: a quantitative proteomic analysis.

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    Babu Raman

    Full Text Available BACKGROUND: Economic feasibility and sustainability of lignocellulosic ethanol production requires the development of robust microorganisms that can efficiently degrade and convert plant biomass to ethanol. The anaerobic thermophilic bacterium Clostridium thermocellum is a candidate microorganism as it is capable of hydrolyzing cellulose and fermenting the hydrolysis products to ethanol and other metabolites. C. thermocellum achieves efficient cellulose hydrolysis using multiprotein extracellular enzymatic complexes, termed cellulosomes. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we used quantitative proteomics (multidimensional LC-MS/MS and (15N-metabolic labeling to measure relative changes in levels of cellulosomal subunit proteins (per CipA scaffoldin basis when C. thermocellum ATCC 27405 was grown on a variety of carbon sources [dilute-acid pretreated switchgrass, cellobiose, amorphous cellulose, crystalline cellulose (Avicel and combinations of crystalline cellulose with pectin or xylan or both]. Cellulosome samples isolated from cultures grown on these carbon sources were compared to (15N labeled cellulosome samples isolated from crystalline cellulose-grown cultures. In total from all samples, proteomic analysis identified 59 dockerin- and 8 cohesin-module containing components, including 16 previously undetected cellulosomal subunits. Many cellulosomal components showed differential protein abundance in the presence of non-cellulose substrates in the growth medium. Cellulosome samples from amorphous cellulose, cellobiose and pretreated switchgrass-grown cultures displayed the most distinct differences in composition as compared to cellulosome samples from crystalline cellulose-grown cultures. While Glycoside Hydrolase Family 9 enzymes showed increased levels in the presence of crystalline cellulose, and pretreated switchgrass, in particular, GH5 enzymes showed increased levels in response to the presence of cellulose in general

  1. Anaerobic microplate assay for direct microbial conversion of switchgrass and Avicel using Clostridium thermocellum

    Energy Technology Data Exchange (ETDEWEB)

    Oguntimein, Gbekeloluwa B. [Morgan State Univ., Baltimore, MD (United States); Rodriguez, Jr., Miguel [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); National Lab., Oak Ridge, TN (United States). BioEnergy Science Center; Dumitrache, Alexandru [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); National Lab., Oak Ridge, TN (United States). BioEnergy Science Center; Shollenberger, Todd [National Renewable Energy Lab. (NREL), Golden, CO (United States); Decker, Stephen R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Davison, Brian H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); National Lab., Oak Ridge, TN (United States). BioEnergy Science Center; Brown, Steven D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); National Lab., Oak Ridge, TN (United States). BioEnergy Science Center; LanzaTech, Inc., Skokie, IL (United States)

    2017-11-09

    Here, to develop and prototype a high-throughput microplate assay to assess anaerobic microorganisms and lignocellulosic biomasses in a rapid, cost-effective screen for consolidated bioprocessing potential. Clostridium thermocellum parent Δhpt strain deconstructed Avicel to cellobiose, glucose, and generated lactic acid, formic acid, acetic acid and ethanol as fermentation products in titers and ratios similar to larger scale fermentations confirming the suitability of a plate-based method for C. thermocellum growth studies. C. thermocellum strain LL1210, with gene deletions in the key central metabolic pathways, produced higher ethanol titers in the Consolidated Bioprocessing (CBP) plate assay for both Avicel and switchgrass fermentations when compared to the Δhpt strain. A prototype microplate assay system is developed that will facilitate high-throughput bioprospecting for new lignocellulosic biomass types, genetic variants and new microbial strains for bioethanol production.

  2. Developing County-level Water Footprints of Biofuel Produced from Switchgrass and Miscanthus x Giganteus in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Wu, May M. [Argonne National Lab. (ANL), Argonne, IL (United States); Chiu, Yi-Wen [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-09-30

    Perennial grass has been proposed as a potential candidate for producing cellulosic biofuel because of its promising productivity and benefits to water quality, and because it is a non-food feedstock. While extensive research focuses on selecting and developing species and conversion technologies, the impact of grass-based biofuel production on water resources remains less clear. As feedstock growth requires water and the type of water consumed may vary considerably from region to region, water use must be characterized with spatial resolution and on a fuel production basis. This report summarizes a study that assesses the impact of biofuel production on water resource use and water quality at county, state, and regional scales by developing a water footprint of biofuel produced from switchgrass and Miscanthus × giganteus via biochemical conversion.

  3. Understanding the Impacts of AFEX™ Pretreatment and Densification on the Fast Pyrolysis of Corn Stover, Prairie Cord Grass, and Switchgrass.

    Science.gov (United States)

    Sundaram, Vijay; Muthukumarappan, Kasiviswanathan; Gent, Stephen

    2017-03-01

    Lignocellulosic feedstocks corn stover, prairie cord grass, and switchgrass were subjected to ammonia fiber expansion (AFEX™) pretreatment and densified using extrusion pelleting and ComPAKco densification technique. The effects of AFEX™ pretreatment and densification were studied on the fast pyrolysis product yields. Feedstocks were milled in a hammer mill using three different screen sizes (2, 4, and 8 mm) and were subjected to AFEX™ pretreatment. The untreated and AFEX™-pretreated feedstocks were moisture adjusted at three levels (5, 10, and 15 % wb) and were extruded using a lab-scale single screw extruder. The barrel temperature of the extruder was maintained at 75, 100, and 125 °C. Durability of the extruded pellets made from AFEX™-pretreated corn stover, prairie cord grass, and switchgrass varied from 94.5 to 99.2, 94.3 to 98.7, and 90.1 to 97.5 %, respectively. Results of the thermogravimetric analysis showed the decrease in the decomposition temperature of the all the feedstocks after AFEX™ pretreatment indicating the increase in thermal stability. Loose and densified feedstocks were subjected to fast pyrolysis in a lab-scale reactor, and the yields (bio-oil and bio-char) were measured. Bio-char obtained from the AFEX™-pretreated feedstocks exhibited increased bulk and particle density compared to the untreated feedstocks. The properties of the bio-oil were statistically similar for the untreated, AFEX™-pretreated, and AFEX™-pretreated densified feedstocks. Based on the bio-char and bio-oil yields, the AFEX™-pretreated feedstocks and the densified AFEX™-pretreated feedstocks (pellets and PAKs) exhibited similar behavior. Hence, it can be concluded that densifying the AFEX™-pretreated feedstocks could be a viable option in the biomass-processing depots to reduce the transportation costs and the logistical impediments without affecting the product yields.

  4. Producción y calidad del forraje diferido de Panicum coloratum L. en dos periodos de diferimiento y tres momentos de defoliación Production and quality of Panicum coloratum L. deferred forage with two deferred period and three times of defolation

    Directory of Open Access Journals (Sweden)

    M.R. Steinberg

    2012-06-01

    Full Text Available Los sistemas pecuarios de las áreas subtropicales de la Argentina utilizan en invierno forrajes diferidos, provenientes del crecimiento acumulado en verano de gramíneas megatérmicas o pasturas naturales. El objetivo del trabajo fue determinar la producción de materia seca, porcentajes de hojas, tallos, proteína bruta, fibra detergente neutra, fibra detergente ácida, cenizas y digestibilidad del diferido de Panicum coloratum cv Verde. Se evaluaron dos periodos de diferimiento: diferido total (DT, forraje acumulado desde el rebrote en primavera y diferido parcial (DP, forraje acumulado desde un corte a fines de diciembre y ambos con tres oportunidades de defoliación: temprano (mayo; intermedio (julio y tardío (agosto. DT produjo más materia seca, pero con alta proporción de tallos, mayor cantidad de fibra y menor porcentaje de proteínas y cenizas; mientras que DP presentó menos tallos y más hojas y como consecuencia mayor porcentaje de proteínas y cenizas. Se concluye que P. coloratum es un recurso adecuado para diferir, sólo si se lo utiliza con un período corto de diferido y momentos tempranos de uso, ya que presenta un nivel mínimo de proteína suficiente para satisfacer los requerimientos de los animales sin la necesidad de realizar suplementación nitrogenada y valores superiores al 55% de digestibilidad.During winter the livestock production systems in subtropical areas of Argentina use deferred forage of native pasture or warm season grasses from the cumulative growth of the summer. The aim of this study was to determine dry matter production and percentage of leaves, stems, crude protein, neutral detergent fiber, acid detergent fiber, ash and digestibility of deferred forage of Panicum coloratum cv Verde. Two deferred periods were evaluated: total deferred (TD, forage accumulated since the spring regrowth and partial deferred (PD, forage accumulated from a cut in late December, and both with three cut dates: early (May

  5. Effect of the populational densities of Panicum maximum (cultivar Tanzânia in phytoremediation of polluted soil with picloram herbicide / Efeito da densidade populacional de Panicum maximum (cultivar Tanzânia na fitorremediação de solo contaminado com o herbicida picloram

    Directory of Open Access Journals (Sweden)

    Leandro Pereira Pacheco

    2009-07-01

    Full Text Available This research was carried out from September of 2006 to February of 2007, under greenhouse conditions, in Rio Verde –GO/ Brazil to study the influence of Panicum maximum populational density on the phytoremediation of soil contaminated with picloram. The treatments were the combination of four Panicum maximum (cultivar Tanzânia populational densities (0, 5, 10 e 15 plants per pot, corresponding to a 0, 122, 244 and 366 plants m-2, respectively and three rates of picloram (0, 80 and 160 g ha-1 applied directly on the pots, simulating levels of soil contamination. After cultivating the phytoremediator specie on substrate during 100 days, soybean Glycine max L was sown at the same pot, used as a phytotoxicity bioindicator specie. Height of plants and green and dry mass of the above ground part of soybean were evaluated. The population density of the phytoremediate species Tanzania influenced the level of phytotoxicity of the herbicide picloram soybean crop sowed in succession. The population density of , 122 plants m-2 was the most efficient in the decontamination of the soil.O objetivo desse trabalho foi avaliar a influência da densidade populacional de Panicum maximum (cultivar Tanzânia sobre a fitorremediação de solo contaminado com o herbicida picloram. O experimento foi conduzido em casa-de-vegetação, de setembro de 2006 a fevereiro de 2007. Os tratamentos foram compostos pela combinação entre quatro densidades populacionais da espécie vegetal Panicum maximum (cultivar Tanzânia (0, 5, 10 e 15 plantas por vaso, equivalentes a 0, 122, 244 e 366 plantas m2, respectivamente e de três doses do picloram (0, 80 e 160 g ha-1 aplicadas diretamente nos vasos, simulando níveis de contaminação do solo. Após o cultivo da espécie fitorremediadora por 100 dias, efetuou-se, no próprio vaso, a semeadura da espécie bioindicadora da presença do picloram, soja (cultivar Monsoy 6101, na qual foram avaliadas a fitotoxicidade, a altura de

  6. Timpanismo gastrointestinal em equídeos alimentados com Panicum maximum com alto conteúdo de amido

    Directory of Open Access Journals (Sweden)

    Taciane M. Souza

    Full Text Available RESUMO: Timpanismo intestinal agudo em cavalos e mulas introduzidos em pastagens de Panicum maximum cv. Tanzânia, cv. Massai e cv. Mombaça são relatados na região norte do Brasil, durante o período das chuvas. As causas são desconhecidas, porém, tem sido sugerido que estão associados a um maior armazenamento de carboidratos não fibrosos na gramínea. Este trabalho teve por objetivos realizar um levantamento epidemiológico dos surtos de cólicas ocorridos no Estado de Rondônia, assim como contribuir com o estudo da ação dos carboidratos de P. maximum na ocorrência da doença. Para isso foram realizadas visitas em 10 propriedades que apresentaram casos da enfermidade. Em duas propriedades foram introduzidos equinos no mês de março e foram coletadas amostras de pastagens para a determinação de energia digestiva, lisina, matéria seca, carboidratos solúveis em água, carboidratos solúveis em éter, carboidratos não fibrosos, fibra de detergente neutra, fibra de detergente ácido, lignina, amido, gordura e proteína bruta. Essas determinações foram realizadas, também, em amostras de pastagens de P. maximum de outras propriedades onde não estavam ocorrendo cólicas e das pastagens de Cynodon dactylon de onde provinham os equinos. Os resultados mostraram que os surtos de cólica ocorrem na época de chuva, quando as pastagens estão rebrotando com uma morbidade de 31,6%, e letalidade de 86,1%. As análises bromatológicas mostraram uma diferença significativa nas concentrações de amido (P=0,0072 do P. maximum que causou cólica (8,3 % e 9,2%, quando comparado com o P. maximum das outras propriedades (0,9% e 4,3% e com o Tifton, utilizado previamente na alimentação dos mesmos equinos (0,2% e 0,8%. Em outra fazenda a doença foi reproduzida experimentalmente em um equino, no mês de março administrando P. maximum cortado contendo 6,5% de amido. A mesma pastagem não causou cólica quando foi administrada a equinos entre os

  7. Uptake of Germanium and Rare Earth Elements (La, Gd, Er, Nd) by white mustard (Brassica alba L.) and common millet (Panicum milliaceum L.) as affected by Phosphorus Nutrition

    Science.gov (United States)

    Zill, Juliane; Wiche, Oliver

    2015-04-01

    The effect of phosphate nutrition is important due to the future usage of fertilizer treatment in phytomining experiments e.g. in accumulation of the economically important rare earth elements (REE). It is expected that the trivalent charge of REE will result in complexation with phosphate and REEs could be immobilized and not further bioavailable for plants which would cause losses of REE concentration in biomass. To investigate this influence on lanthanum, neodymium, gadolinium and erbium two plant species Brassica alba (white mustard) and Panicum miliaceum (common millet) were cultured in a greenhouse study. The plants were cultivated onto two different substrates and were poured with modified REE and phosphate solutions within an eight-week period. The concentrations of REE in soil, soil solution and plant samples were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The results show an increase of concentration of REE with increasing levels of element solution applied for both species. REE accumulations are elevated in roots and decrease in the order of roots> leaves> stem> fruit/blossom. Brassica accumulated more REE in root whereas Panicum showed higher REE concentrations in leaves. Exposure to increased phosphate addition did not significantly change the concentrations of REE in both plant species yet the REE concentrations in leaves slightly decreased with increasing phosphate addition. For root and stem no precise trend could be determined. It is most likely that REEs precipitate with phosphate on root surfaces and in the roots. The bioavailability of REE to plants is affected by complexation processes of REEs with phosphate in the rhizosphere. The results indicate that phosphate application plays an important role on REE uptake by roots and accumulation in different parts of a plant and it might have an influence on translocation of REE within the plant.

  8. Topgrass. A trial of the suitability of switchgrass and reed canary grass as biofuel crops under UK conditions. 4th interim report

    Energy Technology Data Exchange (ETDEWEB)

    Riche, A.B.

    2004-04-01

    This report summarises the results of the Topgrass project growing miscanthus, switchgrass and reed canary grass at nine UK sites and covers a one year period between the winter harvesting of the plots in 2002/3 and 2003/4. Details are given of the rainfall, air temperature and solar radiation; crop monitoring for pests, diseases and weeds; crop measurements; and a comparison of all sites. Appendices present individual site diaries and individual site operations and costs.

  9. Conversion of ammonia-pretreated switchgrass to biofuel precursors by bacterial-fungal consortia under solid-state and submerged-state cultivation.

    Science.gov (United States)

    Jain, A; Pelle, H S; Baughman, W H; Henson, J M

    2017-04-01

    The aim of this study was to develop and evaluate bacterial-fungal communities to deconstruct switchgrass to biofuel precursors. Bacterial-fungal consortia, mesophilic (25°C) and thermophilic (50°C), were enriched from switchgrass bales from which enzyme mixtures were used to deconstruct delignified switchgrass (DSG). The bacterial-fungal consortia were able to produce enzymes including endoglucanase, exoglucanase, β-glucosidase, xylanase, xylosidase and pectinase to convert DSG to soluble carbohydrates. 454 pyrosequencing revealed that Paenibacillus and Streptomyces were the dominant bacteria in the mesophilic and thermophilic consortia respectively. Penicillium and Acremonium were the dominant fungi in the mesophilic consortia, whereas Aspergillus and Penicillium were the dominant fungi present in the thermophilic consortia. The results show that the state of cultivation, solid-state or submerged-state, affects the community structure as well as enzyme activities produced by these bacterial-fungal consortia. The enzyme mixture produced by the bacterial-fungal consortia released a higher amount of xylose than glucose during saccharification of DSG. The study provides a novel approach to produce enzymes for conversion of lignocellulolytic feedstocks to soluble sugars which can be used to produce biofuel precursors. © 2016 The Society for Applied Microbiology.

  10. Effects of forest-based bioenergy feedstock production on shallow groundwater quality of a drained forest soil.

    Science.gov (United States)

    Cacho, Julian F; Youssef, Mohamed A; Chescheir, George M; Wayne Skaggs, R; Appelboom, Timothy W; Leggett, Zakiya H; Sucre, Eric B; Nettles, Jami E; Arellano, Consuelo

    2018-03-05

    Managed forests in southern U.S. are a potential source of lignocellulosic biomass for biofuel production. Changes in management practices to optimize biomass production may impact the quality of waters draining to nutrient-sensitive waters in coastal plain regions. We investigated shallow groundwater quality effects of intercropping switchgrass (Panicum virgatum L.) with managed loblolly pine (Pinus taeda L.) to produce bioenergy feedstock and quality sawtimber in a poorly drained soil of eastern North Carolina, U.S.A. Treatments included PINE (traditional pine production), PSWITCH (pine-switchgrass intercropped), SWITCH (switchgrass monoculture) and REF (mature loblolly pine stand). Each treatment was replicated three times on 0.8ha plots drained by parallel-open ditches, 1.0-1.2m deep and 100m apart. Water samples were collected monthly or more frequently after fertilizer application. Water samples were analyzed for organic nitrogen (ON), ammonium N (NH 4 + - N), and nitrite+nitrate N (NO 3 - + NO 2 - - N), ortohophosphate phosphorus (OP), and total organic carbon (TOC). Overall, PSWITCH did not significantly affect shallow groundwater quality relative to PINE and SWITCH. ON, NO 3 - + NO 2 - - N, and TOC concentrations in PSWITCH, PINE and SWITCH were substantially elevated during the two years after tree harvest and site establishment. The elevated nutrient concentrations at the beginning of the study were likely caused by a combination of rapid organic matter decomposition of the abundant supply of post-harvest residues, warming of exposed soil surfaces and reduction of plant nutrient uptake that can occur after harvesting, and pre-plant fertilization. Nutrient concentrations returned to background levels observed in REF during the third year after harvest. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Global transcriptome analysis of Clostridium thermocellum ATCC 27405 during growth on dilute acid pretreated Populus and switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Charlotte M [ORNL; Rodriguez Jr, Miguel [ORNL; Johnson, Courtney M [ORNL; Martin, S L. [North Carolina State University; Chu, Tzu Ming [SAS Institute; Wolfinger, Russ [SAS Institute; Hauser, Loren John [ORNL; Land, Miriam L [ORNL; Klingeman, Dawn Marie [ORNL; Tschaplinski, Timothy J [ORNL; Mielenz, Jonathan R [ORNL; Brown, Steven D [ORNL

    2013-01-01

    Background The thermophilic anaerobe Clostridium thermocellum is a candidate consolidated bioprocessing (CBP) biocatalyst for cellulosic ethanol production. The aim of this study was to investigate C. thermocellum genes required to ferment biomass substrates and to conduct a robust comparison of DNA microarray and RNA sequencing (RNA-seq) analytical platforms. Results C. thermocellum ATCC 27405 fermentations were conducted with a 5 g/L solid substrate loading of either pretreated switchgrass or Populus. Quantitative saccharification and inductively coupled plasma emission spectroscopy (ICP-ES) for elemental analysis revealed composition differences between biomass substrates, which may have influenced growth and transcriptomic profiles. High quality RNA was prepared for C. thermocellum grown on solid substrates and transcriptome profiles were obtained for two time points during active growth (12 hours and 37 hours postinoculation). A comparison of two transcriptomic analytical techniques, microarray and RNA-seq, was performed and the data analyzed for statistical significance. Large expression differences for cellulosomal genes were not observed. We updated gene predictions for the strain and a small novel gene, Cthe_3383, with a putative AgrD peptide quorum sensing function was among the most highly expressed genes. RNAseq data also supported different small regulatory RNA predictions over others. The DNA microarray gave a greater number (2,351) of significant genes relative to RNA-seq (280 genes when normalized by the kernel density mean of M component (KDMM) method) in an analysis of variance (ANOVA) testing method with a 5 % false discovery rate (FDR). When a 2-fold difference in expression threshold was applied, 73 genes were significantly differentially expressed in common between the two techniques. Sulfate and phosphate uptake/utilization genes, along with genes for a putative efflux pump system were some of the most differentially regulated transcripts

  12. Análise de repetibilidade de caracteres forrageiros de genótipos de Panicum maximum, avaliados com e sem restrição solar Repeatability analysis of forage traits of Panicum maximum genotypes evaluated under natural and attenuated solar radiation

    Directory of Open Access Journals (Sweden)

    Alberto Cargnelutti Filho

    2004-06-01

    Full Text Available O objetivo do trabalho foi determinar o número de medições necessárias à predição do desempenho de cinco genótipos de Panicum maximum Jacq. Os genótipos (Gatton, Vencedor, Mombaça, Tanzânia e Tobiatã foram avaliados sob os sistemas de cultivo com e sem restrição solar, na Fundação Estadual de Pesquisa Agropecuária, situada em Tupanciretã - Rio Grande do Sul. No sistema de cultivo com restrição solar, os genótipos foram avaliados sob um bosque de eucalipto. Em cada uma das oito medições (cortes, foram avaliadas a matéria seca total, matéria seca de folhas, matéria seca de colmo, matéria seca folha + colmo, altura de planta e relação matéria seca folha/colmo. As estimativas dos coeficientes de repetibilidade foram obtidas por três métodos - análise da variância, componentes principais e análise estrutural. Concluiu-se que os oito cortes possibilitaram selecionar genótipos superiores em relação a todas as características, com 80% de exatidão no prognóstico de seu valor real.The objective of this study was to determine how many evaluations were necessary to predict the performance of Panicum maximum Jacq. genotypes. The genotypes Gatton, Vencedor, Mombaça, Tanzânia, and Tobiatã were evaluated under natural and attenuated solar radiation at the Fundação Estadual de Pesquisa Agropecuária, Tupanciretã, RS. Attenuated solar radiation was obtained when plants were grown in Eucalyptus woods. Genotypes in both crop systems were evaluated eight times. Total dry matter production, leaf, stem, and leaf plus stem dry matter, plant height and index of leaf and stem dry matter were recorded each evaluation time. Repeatability estimations were obtained through variance, structural, and principal component analysis. In conclusion, eight evaluations permit to select superior Panicum maximum genotypes, considering all characteristics, with 80% accuracy of the real value.

  13. Efectos del forraje diferido como cobertura de invierno en el crecimiento primaveral de las gramíneas tropicales Chloris gayana y Panicum coloratum

    Directory of Open Access Journals (Sweden)

    José A. Imaz

    2017-01-01

    Full Text Available En La Plata, Buenos Aires, Argentina, en un experimento en macetas a aire libre (condiciones de luz y temperatura naturales se evaluó el efecto del forraje diferido como cobertura invernal en 2 gramíneas tropicales C4 (Chloris gayana y Panicum coloratum. Plantas adultas fueron extraídas de un establecimiento ganadero, trasplantadas a macetas en un jardín experimental y después de crecer durante 111 días (2 de Febrero al 23 de Mayo sometidas a los tratamientos: (1 control [sin remoción del forraje diferido de otoño (DF]; y (2 remoción del forraje diferido de otoño (DFR a 15 cm del suelo. Se utilizaron 10 repeticiones por tratamiento y una planta por maceta (unidad experimental. Las plantas fueron cosechadas el 27 de Septiembre (después del invierno y nuevamente en Noviembre para medir la biomasa del rebrote primaveral en los estratos superior (>15 cm e inferior (<15 cm sobre el suelo, láminas, vainas y estolones. Se realizó un análisis alométrico para dilucidar la incidencia del estrés por frio y se registraron la temperatura del aire, la humedad relativa y la ocurrencia de heladas. Las plantas con forraje diferido alcanzaron una mayor biomasa (55‒80% que aquellas con remoción del forraje. Panicum coloratum mostró un ajuste significativo entre la biomasa total y la biomasa de los diferentes estratos para ambos tratamientos, mostrando buena tolerancia al estrés por frio. Por otro lado, C. gayana mostró  falta de ajuste de la biomasa y un mayor estrés por la remoción del forraje, mientras que las plantas sin remoción presentaron menor daño por frío y un mayor ajuste. La cobertura invernal del forraje diferido podría mejorar la productividad y supervivencia de estas especies forrajeras cuando son utilizadas en sistemas pastoriles templados. Estos resultados preliminares deben ser evaluados en condiciones de campo durante un mayor número de años, considerando diferentes estrategias de pastoreo. Palabras clave: Cobertura

  14. Uso de efluentes da carcinicultura na irrigação de Panicum maximum cvs. Tanzânia e Mombaça

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    Fábio Rodrigues de Miranda

    Full Text Available Resumo O trabalho objetivou avaliar as alterações químicas do solo e a produção de duas cultivares de capim Panicum maximum Jacq. (Tanzânia e Mombaça, em resposta à irrigação com o efluente da carcinicultura em águas interiores e comparar os resultados com os obtidos com a irrigação convencional, utilizando água de rio. O experimento foi realizado em uma fazenda de criação de camarão, em Russas-CE. Utilizou-se um delineamento experimental de blocos casualizados, em um esquema fatorial 2 (cultivares de capim x 2 (tipos de água utilizada na irrigação. Em quatro cortes do capim foram avaliadas as variáveis de produção: altura, produtividade de matéria seca e porcentagem de matéria seca. Os dados foram submetidos à análise de variância e ao teste de Tukey. Foram analisados, antes e após a aplicação dos tratamentos, os seguintes atributos químicos do solo: pH, condutividade elétrica do extrato saturado (CEes, porcentagem de sódio trocável (PST, matéria orgânica, P, K+, Ca2+, Mg2+ e Na+. Os dados foram submetidos ao teste de t , com nível de significância de 5%. A irrigação com o efluente da carcinicultura não aumentou nem reduziu, significativamente, a produção de matéria seca das duas cultivares de Panicum maximum, em comparação com a irrigação com a água do rio Jaguaribe. Após 14 meses de cultivo, o solo irrigado com o efluente apresentou níveis significativamente maiores (p < 0,05 de Na+, CEes e PST em relação ao solo irrigado com a água do rio Jaguaribe.

  15. Downregulation of cinnamyl-alcohol dehydrogenase in switchgrass by RNA silencing results in enhanced glucose release after cellulase treatment.

    Science.gov (United States)

    Saathoff, Aaron J; Sarath, Gautam; Chow, Elaine K; Dien, Bruce S; Tobias, Christian M

    2011-01-27

    Cinnamyl alcohol dehydrogenase (CAD) catalyzes the last step in monolignol biosynthesis and genetic evidence indicates CAD deficiency in grasses both decreases overall lignin, alters lignin structure and increases enzymatic recovery of sugars. To ascertain the effect of CAD downregulation in switchgrass, RNA mediated silencing of CAD was induced through Agrobacterium mediated transformation of cv. "Alamo" with an inverted repeat construct containing a fragment derived from the coding sequence of PviCAD2. The resulting primary transformants accumulated less CAD RNA transcript and protein than control transformants and were demonstrated to be stably transformed with between 1 and 5 copies of the T-DNA. CAD activity against coniferaldehyde, and sinapaldehyde in stems of silenced lines was significantly reduced as was overall lignin and cutin. Glucose release from ground samples pretreated with ammonium hydroxide and digested with cellulases was greater than in control transformants. When stained with the lignin and cutin specific stain phloroglucinol-HCl the staining intensity of one line indicated greater incorporation of hydroxycinnamyl aldehydes in the lignin.

  16. Environmental Performance of Miscanthus, Switchgrass and Maize: Can C4 Perennials Increase the Sustainability of Biogas Production?

    Directory of Open Access Journals (Sweden)

    Andreas Kiesel

    2016-12-01

    Full Text Available Biogas is considered a promising option for complementing the fluctuating energy supply from other renewable sources. Maize is currently the dominant biogas crop, but its environmental performance is questionable. Through its replacement with high-yielding and nutrient-efficient perennial C4 grasses, the environmental impact of biogas could be considerably improved. The objective of this paper is to assess and compare the environmental performance of the biogas production and utilization of perennial miscanthus and switchgrass and annual maize. An LCA was performed using data from field trials, assessing the impact in the five categories: climate change (CC, fossil fuel depletion (FFD, terrestrial acidification (TA, freshwater eutrophication (FE and marine eutrophication (ME. A system expansion approach was adopted to include a fossil reference. All three crops showed significantly lower CC and FFD potentials than the fossil reference, but higher TA and FE potentials, with nitrogen fertilizer production and fertilizer-induced emissions identified as hot spots. Miscanthus performed best and changing the input substrate from maize to miscanthus led to average reductions of −66% CC; −74% FFD; −63% FE; −60% ME and −21% TA. These results show that perennial C4 grasses and miscanthus in particular have the potential to improve the sustainability of the biogas sector.

  17. Influência do oeríodo de cultivo de Panicum maximum (cultivar Tanzânia na fitorremediação de solo contaminado com picloram Influence of Panicum maximum cultivation period on phytoremediation of soil contaminated with picloram

    Directory of Open Access Journals (Sweden)

    M.L. Carmo

    2008-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a influência do tempo de cultivo de Panicum maximum (cultivar Tanzânia sobre a fitorremediação de solo contaminado com picloram. O experimento foi conduzido em casa de vegetação no período de setembro de 2006 a fevereiro de 2007. Os fatores foram compostos pela combinação entre quatro períodos de cultivo da espécie vegetal Panicum maximum (cultivar Tanzânia (0, 60, 80 e 100 dias e três doses do picloram (0, 80 e 160 g ha-1, totalizando 12 tratamentos. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 4 x 3, com quatro repetições. Como substrato utilizaram-se amostras de solo classificado como Latossolo Vermelho eutroférrico. Após o tempo estabelecido de atuação da espécie fitorremediadora, efetuou-se a semeadura das espécies bioindicadoras da presença do picloram: tomate e soja. As espécies bioindicadoras demonstraram alta sensibilidade à presença do picloram no solo, sendo inviável o cultivo dessas culturas em áreas contaminadas com esse herbicida sem a execução de algum procedimento remediador. O cultivo prévio de Tanzânia por 60 dias garantiu crescimento inicial satisfatório das plantas de soja e tomate quando a contaminação inicial não foi maior que 80 g ha-1 de picloram. Acima desse valor, a fitorremediação ocorrida proporcionou menor crescimento das plantas de soja e tomate, sendo necessário maior tempo de descontaminação.The objective of this study was to evaluate the influence of cultivation time of Panicum maximum (cv. Tanzania on phyto-remediation of soil contaminated with picloram. The experiment was carried out under greenhouse conditions from September 2006 to February 2007, using euthroferric Red Latosol samples as substrate for plant growth. The experiment was arranged in a completely randomized design, with four replicates, with treatments in a 4 x 3 factorial scheme. The treatments comprised twelve combinations of

  18. Características agronômicas, morfogênicas e estruturais do capim "Panicum maximum" cv. Mombaça sob desfolhação intermitente Characteristics agronomic, morphogenic and structural of the “Panicum maximum” cv. Mombaça grass under intermittent defoliation

    OpenAIRE

    Rafael Henrique Pereira dos Reis; Roberta Gomes Marçal Vieira Vaz; Adriano Jakelaitis; Emerson Alexandrino; Carlos Henrique Oliveira Macedo; Jhony Vendrusculo

    2010-01-01

    Avaliou-se o efeito de dois períodos de descanso sobre as características morfogênicas, estruturais e o acúmulo de forragem do Panicum maximum cv. Mombaça estabelecido na Amazônia Legal. Os tratamentos foram dispostos em delineamento em blocos ao acaso, com quatro repetições. Os períodos avaliados foram de 36 e 48 dias de rebrotação, com 25 cm de altura do corte. Para as características agronômicas avaliadas, apenas a produção de matéria seca de lâmina foliar não foi incrementada com o prolon...

  19. Efeito do manejo sobre a produção e composição química de perfilhos do capim-colonião (Panicum maximum Jacq. Effect of management on the chemical composition and tillers production of colonião grass (Panicum maximum Jacq.

    Directory of Open Access Journals (Sweden)

    Jane Maria Bertocco Ezequiel

    2000-12-01

    Full Text Available O experimento foi conduzido com o objetivo de verificar os efeitos das freqüências de corte de 28, 35 e 42 dias, obtidas em dezembro, janeiro e fevereiro, cortadas rente a 15 cm e a 30 cm do solo, sobre a produção e composição química de perfilhos do capim-colonião. A área experimental foi adubada na semeadura e por ocasião dos cortes de uniformização. Verificou-se que a produção de MS foi o principal fator da produção de nutrientes por área. Os teores de PB dos perfilhos apresentaram comportamento não-linear com o avanço da idade e diminuíram sensivelmente a baixas alturas e altas freqüências de corte. Os teores de FDA dos perfilhos variaram pouco entre as idades de 28 e 42 dias. Concluiu-se que o melhor manejo do capim-colonião seria o corte a cada 42 dias e a 15 cm do solo.The effects of cutting frequency of 28, 35 and 42 days, performed in December, January and February at 0 cm, 15 cm and 30 cm from the ground on the chemical composition and tiller production of Panicum maximum Jacq were assayed. The experimental area was fertilized during the sowing, at uniform cuttings. Dry matter yield was the main factor affecting the nutrients production by area. The crude protein content of tillers showed no linear response to the cutting interval and sensitively decrease at low cutting height and high cutting frequency. The ADF concentrations of tillers exhibited small variation within the interval of growth period studied of 28 to 42 days. The best management for Panicum maximum could be at 42 days cutting frequency at 15 cm from the ground.

  20. DESEMPENHOS TÉCNICOS E ECONÔMICOS DA CONSORCIAÇÃO DE MILHO COM FORRAGEIRAS DOS GÊNEROS Panicum E Brachiaria EM SISTEMA DE INTEGRAÇÃO LAVOURA-PECUÁRIA TECHNICAL AND ECONOMIC PERFORMANCE OF CORN INTERCROPPED WITH Panicum AND Brachiaria FORAGE IN CROP-LIVESTOCK INTEGRATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Carlos Alessandro Chioderoli

    2009-10-01

    Full Text Available

    O trabalho teve como objetivo analisar a produtividade de grãos e os resultados econômicos de modalidades do cultivo de milho com forrageiras dos gêneros Panicum e Brachiaria, na integração lavoura-pecuária (ILP, sob sistema plantio direto (SPD. O experimento foi conduzido no ano agrícola de 2007/2008, no município de Selvíria, MS, em Latossolo Vermelho distroférrico. O delineamento experimental utilizado foi o de blocos casualizados, com quatro repetições, sendo os tratamentos constituídos por oito modalidades de cultivo do milho consorciado, simultaneamente e por ocasião da adubação nitrogenada de cobertura com os capins Tanzânia, Mombaça, Marandu e Ruziziensis, além do seu cultivo sem consórcio. A análise dos custos operacionais foi baseada nos preços de insumos e operações e a receita bruta no preço médio de venda do milho, no Estado de São Paulo. O decréscimo dos valores da relação custo/benefício e os melhores retornos econômicos, obtidos em função dos maiores índices de margem de contribuição, determinaram as modalidades de cultivo mais viáveis. Os capins Mombaça e Marandu, consorciados, simultaneamente, ao milho, reduziram a produtividade de grãos, em relação ao milho cultivado sem o consórcio. Com relação aos benefícios técnico-econômicos, visando à utilização em sistemas de ILP, o consórcio mais recomendado é o de milho com capim Tânzania, principalmente no cultivo simultâneo. No entanto, resultados técnico-econômicos a longo prazo, com diferentes preços e produtividades, devem ser avaliados

  1. Comparison of two organic fertilizers along with Zn and B elements on concentration, uptake of nutrients and some growth parameters in millet (Panicum miliaceum L.

    Directory of Open Access Journals (Sweden)

    T Nezhad hoseini

    2016-05-01

    Full Text Available A field experiment was conducted to study the effect of two organic fertilizers along with zinc and boron elements on some growth parameters, concentration and uptake of nutrients in millet (Panicum miliaceum L. by using factorial based on randomized completely block design with three replications in Qaen region, Iran. The main treatments were municipal solid waste compost and cow manure (each at 0 and 25 t.ha-1 and sub treatments were elements of Zn (0, 50 kg.ha-1 and B (0, 10 kg.ha-1 using their respective ZnSO4 and H3BO3 salts. Results showed that treatments interaction had significant effects on total dry matter yield, number of tillers per plant and plant height of Millet. The highest total dry matter production was achieved by interaction of cow manure along with Zn and B elements. Concentrations of N, Fe, Zn, B and Cu in plant were increased significantly by treatments interaction effects compared to control. Interaction effect of organic fertilizers with B (in the absence of Zn enhanced plant B concentration significantly, whereas, interaction of organic fertilizers with Zn (in the absence of B decreased B concentration in plant. The highest plant uptake of N, P, K, Zn, and B was observed in plots with cow manure and Zn and B elements.

  2. A trial of the suitability of switchgrass and reed canary grass as biofuel crops under UK conditions. 5th interim report March 2005

    Energy Technology Data Exchange (ETDEWEB)

    Richie, A.B.

    2005-07-01

    The Topgrass Project, established in 2002, investigated the potential of miscanthus, switchgrass and reed canary grass as biofuel crops at various sites in the UK. This interim report covers the period from the harvesting in winter 2003/04 to the harvesting in winter 2004/05. The report gives details on (i) pest and weed control and (ii) yields and associated costs per species per unit area. It was concluded that maximum potential yield has not been reached at some sites. The study was funded by the DTI and carried out by IACR Rothamstead with ADAS Consulting, Duchy College Cornwall and SCRI Invergowrie as collaborators. The project has now terminated.

  3. Nest survival modelling using a multi-species approach in forests managed for timber and biofuel feedstock

    Science.gov (United States)

    Loman, Zachary G.; Monroe, Adrian; Riffell, Samuel K.; Miller, Darren A.; Vilella, Francisco; Wheat, Bradley R.; Rush, Scott A.; Martin, James A.

    2018-01-01

    Switchgrass (Panicum virgatum) intercropping is a novel forest management practice for biomass production intended to generate cellulosic feedstocks within intensively managed loblolly pine‐dominated landscapes. These pine plantations are important for early‐successional bird species, as short rotation times continually maintain early‐successional habitat. We tested the efficacy of using community models compared to individual surrogate species models in understanding influences on nest survival. We analysed nest data to test for differences in habitat use for 14 bird species in plots managed for switchgrass intercropping and controls within loblolly pine (Pinus taeda) plantations in Mississippi, USA.We adapted hierarchical models using hyper‐parameters to incorporate information from both common and rare species to understand community‐level nest survival. This approach incorporates rare species that are often discarded due to low sample sizes, but can inform community‐level demographic parameter estimates. We illustrate use of this approach in generating both species‐level and community‐wide estimates of daily survival rates for songbird nests. We were able to include rare species with low sample size (minimum n = 5) to inform a hyper‐prior, allowing us to estimate effects of covariates on daily survival at the community level, then compare this with a single‐species approach using surrogate species. Using single‐species models, we were unable to generate estimates below a sample size of 21 nests per species.Community model species‐level survival and parameter estimates were similar to those generated by five single‐species models, with improved precision in community model parameters.Covariates of nest placement indicated that switchgrass at the nest site (forest stand level increased daily nest survival.Synthesis and applications. Community models represent a viable method for estimating community nest survival rates and effects of

  4. Nest survival modelling using a multi-species approach in forests managed for timber and biofuel feedstock

    Science.gov (United States)

    Loman, Zachary G.; Monroe, Adrian; Riffell, Samuel K.; Miller, Darren A.; Vilella, Francisco; Wheat, Bradley R.; Rush, Scott A.; Martin, James A.

    2018-01-01

    Switchgrass (Panicum virgatum) intercropping is a novel forest management practice for biomass production intended to generate cellulosic feedstocks within intensively managed loblolly pine‐dominated landscapes. These pine plantations are important for early‐successional bird species, as short rotation times continually maintain early‐successional habitat. We tested the efficacy of using community models compared to individual surrogate species models in understanding influences on nest survival. We analysed nest data to test for differences in habitat use for 14 bird species in plots managed for switchgrass intercropping and controls within loblolly pine (Pinus taeda) plantations in Mississippi, USA.We adapted hierarchical models using hyper‐parameters to incorporate information from both common and rare species to understand community‐level nest survival. This approach incorporates rare species that are often discarded due to low sample sizes, but can inform community‐level demographic parameter estimates. We illustrate use of this approach in generating both species‐level and community‐wide estimates of daily survival rates for songbird nests. We were able to include rare species with low sample size (minimum n = 5) to inform a hyper‐prior, allowing us to estimate effects of covariates on daily survival at the community level, then compare this with a single‐species approach using surrogate species. Using single‐species models, we were unable to generate estimates below a sample size of 21 nests per species.Community model species‐level survival and parameter estimates were similar to those generated by five single‐species models, with improved precision in community model parameters.Covariates of nest placement indicated that switchgrass at the nest site (<4 m) reduced daily nest survival, although intercropping at the forest stand level increased daily nest survival.Synthesis and applications. Community models represent a viable

  5. Combined inactivation of the Clostridium cellulolyticum lactate and malate dehydrogenase genes substantially increases ethanol yield from cellulose and switchgrass fermentations

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yongchao [ORNL; Tschaplinski, Timothy J [ORNL; Engle, Nancy L [ORNL; Hamilton, Choo Yieng [ORNL; Rodriguez, Jr., Miguel [ORNL; Liao, James C [ORNL; Schadt, Christopher Warren [ORNL; Guss, Adam M [ORNL; Yang, Yunfeng [ORNL; Graham, David E [ORNL

    2012-01-01

    Background: The model bacterium Clostridium cellulolyticum efficiently hydrolyzes crystalline cellulose and hemicellulose, using cellulosomes to degrade lignocellulosic biomass. Although it imports and ferments both pentose and hexose sugars to produce a mixture of ethanol, acetate, lactate, H2 and CO2, the proportion of ethanol is low, which impedes its use in consolidated bioprocessing for biofuels. Therefore genetic engineering will likely be required to improve the ethanol yield. Random mutagenesis, plasmid transformation, and heterologous expression systems have previously been developed for C. cellulolyticum, but targeted mutagenesis has not been reported for this organism. Results: The first targeted gene inactivation system was developed for C. cellulolyticum, based on a mobile group II intron originating from the Lactococcus lactis L1.LtrB intron. This markerless mutagenesis system was used to disrupt both the paralogous L-lactate dehydrogenase (Ccel_2485; ldh) and L-malate dehydrogenase (Ccel_0137; mdh) genes, distinguishing the overlapping substrate specificities of these enzymes. Both mutations were then combined in a single strain. This double mutant produced 8.5-times more ethanol than wild-type cells growing on crystalline cellulose. Ethanol constituted 93% of the major fermentation products (by molarity), corresponding to a molar ratio of ethanol to organic acids of 15, versus 0.18 in wild-type cells. During growth on acid-pretreated switchgrass, the double mutant also produced four-times as much ethanol as wild-type cells. Detailed metabolomic analyses identified increased flux through the oxidative branch of the mutant s TCA pathway. Conclusions: The efficient intron-based gene inactivation system produced the first gene-targeted mutations in C. cellulolyticum. As a key component of the genetic toolbox for this bacterium, markerless targeted mutagenesis enables functional genomic research in C. cellulolyticum and rapid genetic engineering to

  6. Bio-butanol vs. bio-ethanol: A technical and economic assessment for corn and switchgrass fermented by yeast or Clostridium acetobutylicum

    Energy Technology Data Exchange (ETDEWEB)

    Pfromm, Peter H. [Department of Chemical Engineering, Kansas State University, 1005 Durland Hall, Manhattan, KS 66506 (United States); Amanor-Boadu, Vincent [Department of Agricultural Economics, Kansas State University, Manhattan, KS 66506 (United States); Nelson, Richard [Center for Sustainable Energy, Kansas State University, Manhattan, KS 66506 (United States); Vadlani, Praveen [Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506 (United States); Madl, Ronald [Center for Sustainable Energy, Kansas State University, Manhattan, KS 66506 (United States); Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506 (United States)

    2010-04-15

    Fermentation-derived butanol is a possible alternative to ethanol as a fungible biomass-based liquid transportation fuel. We compare the fermentation-based production of n-butanol vs. ethanol from corn or switchgrass through the liquid fuel yield in terms of the lower heating value (LHV). Industrial scale data on fermentation to n-butanol (ABE fermentation) or ethanol (yeast) establishes a baseline at this time, and puts recent advances in fermentation to butanol in perspective. A dynamic simulation demonstrates the technical, economic and policy implications. The energy yield of n-butanol is about half that of ethanol from corn or switchgrass using current ABE technology. This is a serious disadvantage for n-butanol since feedstock costs are a significant portion of the fuel price. Low yield increases n-butanol's life-cycle greenhouse gas emission for the same amount of LHV compared to ethanol. A given fermenter volume can produce only about one quarter of the LHV as n-butanol per unit time compared to ethanol. This increases capital costs. The sometimes touted advantage of n-butanol being more compatible with existing pipelines is, according to our techno-economic simulations insufficient to alter the conclusion because of the capital costs to connect plants via pipeline. (author)

  7. COMPOSIÇÃO QUÍMICA DO CAPIM-MOMBAÇA (Panicum maximum Jacq. SUBMETIDO À ADUBAÇÃO ORGÂNICA E MINERAL

    Directory of Open Access Journals (Sweden)

    KARINA ROCHA FREITAS

    2011-09-01

    Full Text Available The objective of this study was to evaluate the chemical composition of Panicum maximum Jacq. fertilized with pig slurry (PS and mineral fertilizer during the rainy season for two consecutive years. The experiment was conducted from October 2004 to March 2005 and fromSeptember 2005 to April 2006. The following treatments were used: Witness=replacement of 3.5 kg/ha of P2O5 and 18 kg/ha of K2O/t of dry matter of forage; TQ=replacement of 3.5 kg/ha of P2O5, 18 kg/ha of K2O/t of dry matter of forage and 300 kg of N/ha/year; T100=100 m3/ha/year of LPW; T150=150 m3/ha/year of LPW; T200=200 m3/ha/year of LPW. The fertilizations were parceled out by the number of cuttings accomplished every year and applied after each cut. The cuttings wereaccomplished every 28 days at 0.30 m of the soil. Macromineral (N, P, K, S, Ca, Mg and microminerals (Cu, Fe, Zn e Mn were assessed in each evaluated period. The experimental design was split-plot random blocks, constituted by the fertilization treatments and by the yearsof evaluation. The chemical composition was influenced by the fertilization with LPW and mineral, as well as by the years of evaluation. The use of 200 m3/ha/ano dose of DLS is recommended.

  8. Optimización de las condiciones de germinación de cuatro especies de pastos tropicales II Brachiaria humidicola y panicum maximum

    Directory of Open Access Journals (Sweden)

    Carlos Gutiérrez

    2006-05-01

    Full Text Available Se evaluó el efecto de diferentes condiciones ambientales y de sustrato sobre la germinación de semilla de los pastos Brachiaria humidicola y Panicum maximum. Los sustratos evaluados fueron: papel, turba y suelo; las condiciones de temperatura fueron: continua a 30 °C y alterna con 8h a 20 °C y 16 h a 30° C. Se utilizaron diferentes contenidos de humedad en los sustratos: papel saturado, turba con 30, 45 y 60%, y suelo con 10, 20 y 30%. Se evaluó el porcentaje de germinación a los 3, 14 y 22 días, la longitud de la plúmula a los 5 días y el peso seco de las plántulas a los 7 días de la Alizaga3siembra. En P. maximum la temperatura no afectó la germinación, mientras que en B. humidicola la temperatura alterna favoreció un mayor porcentaje de plántulas normales. El mayor peso seco y longitud de plúmula se obtuvo con 30 °C. En B. humidicola el mejor sustrato fue turba y en P. maximum papel. La humedad de la turba no tuvo efecto sobre la germinación, en suelo fue crítica únicamente en P. maximum con 10% de humedad. La menor longitud se alcanzó en P. maximum en papel, mientras que en B. humidicola en suelo.

  9. Strategic control of Rhipicephalus (Boophilus) microplus infestation on beef cattle grazed in Panicum maximum grasses in a subtropical semi-arid region of Argentina.

    Science.gov (United States)

    Morel, Nicolás; Signorini, Marcelo L; Mangold, Atilio J; Guglielmone, Alberto A; Nava, Santiago

    2017-09-01

    The aim of this work was to test the efficacy of strategic control methods of Rhipicephalus microplus infestation on beef cattle grazed in Panicum maximum grasses in northwestern Argentina. Also, an analysis to discern how the R. microplus population was distributed amongst cattle was also performed to determine if partial selective treatment or cull the small proportion of more heavily infested animals are feasible options to control this tick. The strategic scheme of treatments was designed to act on the small 1st generation of R. microplus in early spring and prevent in that way the appearance of the annual peak of abundance of R. microplus in summer and autumn. Animals of the group 1 were treated with ivermectin 3.15% on day 0 (25th September 2015), with fluazuron on day 32 (27th October 2015) and with fipronil on day 75 (9th December 2015). Animals of group 2 formed the control group. The overall effect of the treatments was positively significant. The number of ticks observed on the control group was significantly higher than the number of ticks observed on the treated group in all post-treatment counts (Pstrategic control method evaluated during this study provides a remarkable overall effect against R. microplus because it significantly reduces the tick infestation on cattle with only three applications of acaricides in one-year period. The analyses of tick distribution amongst cattle suggest that partial selective treatment and culling do not represent feasible methods to control R. microplus infestation on cattle. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Effect of concentrate supplementation during pre-kidding on the productive and reproductive performance of goats raised on Guinea grass (Panicum maximum cv. Tobiatã pasture

    Directory of Open Access Journals (Sweden)

    Raquel Ornelas Marques

    2016-06-01

    Full Text Available Sixty goats (20 Alpine, 18 Anglo-Nubian, and 22 crossbred Boer, with average body weight 49.33 ± 1.41 kg, were raised on Panicum maximum cv. Tobiatã pasture with two different levels of concentrate supplementation, 300 (SL30 and 600 g kg-1 (SL60 of the daily requirements, and evaluated from the pre-mating season until an average of 110 days of lactation. Milk controls were performed every 14 days. The following milk production curve parameters were estimated: time to reach peak milk production (TP, peak milk production (PP and milk production during the first 110 days of lactation (MP. The following milk components were determined: fat, protein, lactose, total solids (TS, defatted dry extract (DDE, urea nitrogen (UN concentrations, and somatic cell count (SCC. Goat prolificacy and birth weight of the kids were also determined. Breed affected the lactation curve, with Alpine and Anglo- Nubian goats presenting higher TP, PP, and MP. Protein, TS, and DDE concentrations were also affected by breed, being higher for crossbred Boer goats. Milk fat, lactose concentrations, and the log of SCC were affected by the concentrate supplementation level, being higher for SL30, as well as by the breed, with crossbred Boer goats presenting higher fat concentrations and log of SCC, and crossbred Boer and Alpine goats presenting higher lactose concentrations. UN was affected by the stage of lactation. Prolificacy and birth weight were affected by breed and concentrate supplementation level, being higher for Anglo-Nubian and crossbred Boer goats with SL60. Kids from single births presented higher birth weights. The Anglo-Nubian breed presented good milk production and the best body condition, which might indicate the effectiveness of this production system, SL60 supplementation resulted in higher birth weight and prolificacy.

  11. Discovery of linear cyclotides in monocot plant Panicum laxum of Poaceae family provides new insights into evolution and distribution of cyclotides in plants.

    Science.gov (United States)

    Nguyen, Giang Kien Truc; Lian, Yilong; Pang, Edmund Weng Hou; Nguyen, Phuong Quoc Thuc; Tran, Tuan Dinh; Tam, James P

    2013-02-01

    Cyclotides are disulfide-rich macrocyclic peptides that display a wide range of bioactivities and represent an important group of plant defense peptide biologics. A few linear variants of cyclotides have recently been identified. They share a high sequence homology with cyclotides but are biosynthetically unable to cyclize from their precursors. All hitherto reported cyclotides and their acyclic variants were isolated from dicot plants of the Rubiaceae, Violaceae, Cucurbitaceae, and recently the Fabaceae and Solanaceae families. Although several cyclotide-like genes in the Poaceae family were known from the data mining of the National Center for Biotechnology Information (NCBI) nucleotide database, their expression at the protein level has yet to be proven. Here, we report the discovery and characterization of nine novel linear cyclotides, designated as panitides L1-9, from the Panicum laxum of the Poaceae family and provide the first evidence of linear cyclotides at the protein level in a monocot plant. Disulfide mapping of panitide L3 showed that it possesses a cystine knot arrangement similar to cyclotides. Several panitides were shown to be active against Escherichia coli and cytotoxic to HeLa cells. They also displayed a high stability against heat and proteolytic degradation. Oxidative folding of the disulfide-reduced panitide L1 showed that it can fold efficiently into its native form. The presence of linear cyclotides in both dicots and monocots suggests their ancient origin and existence before the divergence of these two groups of flowering plants. Moreover, the Poaceae family contains many important food crops, and our discovery may open up new avenues of research using cyclotides and their acyclic variants in crop protection.

  12. Avaliação dos capins mombaça e massai sob pastejo Evaluation of Panicum maximum cvs Mombaça and Massai under grazing

    Directory of Open Access Journals (Sweden)

    Valéria Pacheco Batista Euclides

    2008-01-01

    Full Text Available Visando à liberação para uso comercial, realizou-se avaliação do capim-massai (Panicum maximum quanto à adaptação e produtividade. No plantio foram utilizados 2,7 t/ha de calcário dolomítico, 500 kg/ha da fórmula 0-20-15 e 50 kg/ha de FTE BR-12. Como adubação de cobertura, efetuaram-se aplicações da fórmula 0-20-20 (200 kg/ha e de nitrogênio (50 kg/ha de N. Os cultivares testados foram Mombaça e Massai. O delineamento experimental foi o de blocos casualizados com dois tratamentos e duas repetições. Os piquetes (1,5 ha foram subdivididos em seis e submetidos ao pastejo rotacionado, com sete dias de utilização e 35 dias de descanso. Foram utilizados quatro animais-teste por piquete e animais reguladores para manter resíduos de MS pós-pastejo superiores a 2 t/ha. Os pastos foram amostrados no pré e no pós-pastejo para se estimarem a massa de forragem, a proporção dos componentes morfológicos e o valor nutritivo. Os animais foram pesados a cada 42 dias. Os animais no pasto de capim-mombaça ganharam mais peso (437 g/novilho.dia que aqueles no pasto de capim-massai (300 g/novilho.dia. No entanto, o capim-massai suportou maior taxa de lotação (2,15 UA/ha que o capim-mombaça (1,86 UA/ha. No entanto, esta maior capacidade de suporte não foi suficiente para compensar o menor ganho de peso vivo dos animais neste pasto (626 kg/ha.ano em comparação àqueles mantidos no pasto de capim-mombaça (691 kg/ha.ano. O desempenho satisfatório, associado a outras importantes características de adaptação, torna o cultivar Massai uma forrageira promissora para a diversificação e viabilização da sustentabilidade de sistema de produção de bovinos de corte.A new cultivar of Panicum maximum (Massai was evaluated for commercial release, at the Embrapa Beef Cattle, Campo Grande, MS, Brazil, from November 1993 to April 1999. At establishment, 2,7 t/ha of lime, 400 kg/ha of 0-20-20 and 50 kg/ha of FTE were applied. Maintenance

  13. Effets de Panicum maximum Jacq. associé à Euphorbia heterophylla (L. Klotz. & Garcke sur la productivité des femelles durant le cycle de reproduction chez le cobaye (Cavia porcellus L.

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    N'G. D.V. Kouakou

    2015-01-01

    Full Text Available Effect of Panicum maximum Jacq. Associated with Euphorbia heterophylla (L. Klotz. & Garcke on Productivity of Females (Cavia porcellus L During the Reproductive Cycle. In Ivory Coast, Guinea pigs reared for meat (Cavia porcellus L. are mainly fed with Panicum maximum Jacq. The association of this forage with Euphorbia heterophylla (L. Klotz. & Garcke improves the organic matter digestibility of the mixed diet compared to P. maximum distributed alone in growing male guinea pigs. In order to determine the effect of this diet during gestation and lactation in female guinea pigs, three diets: P. maximum (PAN basic diet; P. maximum associated to E. heterophylla (PANEUPH and P. maximum associated to pellets for rabbit (PANGRAN, were distributed ad libitum to multiparous guinea pigs (604.9 ± 40.8 g. The daily ingestion during gestation and lactation were 59.8±11.2 and 53.2±8.5; 61.5±5.2 and 72.9±16.4; 83.1±12.9 and 111.3±13.9 g DM.d-1 respectively for PAN, PANEUPH and PANGRAN. Similarly, the rates of fecundity were 111.1±0.9; 188.9±0.6 and 244.4±0.5% respectively for PAN, PANEUPH and PANGRAN. The individual birth weight and weight gain during lactation of the piglets were 58.7±12.4, 75.6±16.2 and 102.5±12 g and 2.4±0.6; 4.1±0.9 and 6.5±1.2 g.d-1 respectively for PAN, PANEUPH, and PANGRAN. In conclusion, the association of P. maximum and E. heterophylla significantly improves ingestion, digestibility, fecundity, birth weight and weaning weight in guinea pigs in comparison to Panicum maximum used as a sole diet.

  14. Efectos del forraje diferido como cobertura de invierno en el crecimiento primaveral de las gramíneas tropicales Chloris gayana y Panicum coloratum

    OpenAIRE

    José A. Imaz; Víctor Merani; Daniel dos Santos; Marcelo Benvenutti; Daniel O. Giménez; Olegario Hernández; José I. Arroquy

    2017-01-01

    En La Plata, Buenos Aires, Argentina, en un experimento en macetas a aire libre (condiciones de luz y temperatura naturales) se evaluó el efecto del forraje diferido como cobertura invernal en 2 gramíneas tropicales C4 (Chloris gayana y Panicum coloratum). Plantas adultas fueron extraídas de un establecimiento ganadero, trasplantadas a macetas en un jardín experimental y después de crecer durante 111 días (2 de Febrero al 23 de Mayo) sometidas a los tratamientos: (1) control [sin remoción del...

  15. Densidade e qualidade dos estratos de forragem do capim Tanzânia (Panicum maximum Jacq. Cv. Tanzânia-1 manejado em diferentes alturas, sob pastejo Density bulk and quality of Tanzania grass layers (Panicum maximum Jacq.cv. Tanzania-1, at different heights in grazing

    Directory of Open Access Journals (Sweden)

    Geraldo Tadeu dos Santos

    2001-05-01

    Full Text Available O objetivo do trabalho foi avaliar o efeito de diferentes alturas (24; 26; 43; 45; 52; 62; 73 e 78 cm do pasto sobre a qualidade de forragem e estrutura do perfil do capim-Tanzânia, (Panicum maximum Jacq. cv. Tanzânia – 1 (Poaceae. Foram utilizados novilhos da raça Nelore sob pastejo com carga animal variável, por meio da técnica put and take. O delineamento experimental utilizado foi inteiramente casualizado, com duas repetições. A densidade de matéria seca total (DMT aumentou com o avanço no período experimental, enquanto a densidade de matéria seca de lâminas (DML não foi influenciada pelo período e pela altura do pasto. O estrato superior da pastagem foi a porção de maior qualidade, apresentando maior DML e maior teor de PB. Os estratos inferiores apresentaram menor qualidade, devido à maior DMT e menor DML, acarretando em maiores valores de FDA e FDN e menores teores de PB. O conteúdo de minerais das lâminas foi superior aos colmos, mantendo-se inalterado com relação aos estratos da pastagem.The effect of different sward heights (24; 26; 43; 45; 52; 62; 73 and 78 cm on forage quality and profile structure Tanzania grass, Panicum maximum Jacq. cv. Tanzania – 1 (Poaceae is provided. Nelore steers were used in grazing at variable stocking rates with put and take technique. The experimental design was completely randomized, with two replications. Total dry matter bulk densitity (TDMD increased during experimental period, while the leaf blade dry matter bulk density (LDMD was not influenced by period on by sward height. The upper layers had the best quality with higher LDMD and CP levels. Lower layers had the worst quality, due the higher TDMD and lower LDMD. This fact caused higher ADF and NDF levels and lower CP levels. Leaf blade mineral content was higher than that of stem, and remained unaltered in relation to the different layers.

  16. The economical and environmental performance of miscanthus and switchgrass production and supply chains in a European setting

    International Nuclear Information System (INIS)

    Smeets, Edward M.W.; Lewandowski, Iris M.; Faaij, Andre P.C.

    2009-01-01

    The purpose of this study is to analyse the economical and environmental performance of switchgrass and miscanthus production and supply chains in the European Union (EU25), for the years 2004 and 2030. The environmental performance refers to the greenhouse gas (GHG) emissions, the primary fossil energy use and to the impact on fresh water reserves, soil erosion and biodiversity. Analyses are carried out for regions in five countries. The lowest costs of producing (including storing and transporting across 100 km) in the year 2004 are calculated for Poland, Hungary and Lithuania at 43-64 EUR per oven dry tonne (odt) or 2.4-3.6 EUR GJ -1 higher heating value. This cost level is roughly equivalent to the price of natural gas (3.1 EUR GJ -1 ) and lower than the price of crude oil (4.6 EUR GJ -1 ) in 2004, but higher than the price of coal (1.7 EUR GJ -1 ) in 2004. The costs of biomass in Italy and the United Kingdom are somewhat higher (65-105 EUR odt -1 or 3.6-5.8 EUR GJ -1 ). The doubling of the price of crude oil and natural gas that is projected for the period 2004-2030, combined with nearly stable biomass production costs, makes the production of perennial grasses competitive with natural gas and fossil oil. The results also show that the substitution of fossil fuels by biomass from perennial grasses is a robust strategy to reduce fossil energy use and curb GHG emissions, provided that perennial grasses are grown on agricultural land (cropland or pastures). However, in such case deep percolation and runoff of water are reduced, which can lead to overexploitation of fresh water reservoirs. This can be avoided by selecting suitable locations (away from direct accessible fresh water reservoirs) and by limiting the size of the plantations. The impacts on biodiversity are generally favourable compared to conventional crops, but the location of the plantation compared to other vegetation types and the size and harvesting regime of the plantation are important variables

  17. Perennial Forages as Second Generation Bioenergy Crops

    Directory of Open Access Journals (Sweden)

    Paul R. Adler

    2008-05-01

    Full Text Available The lignocellulose in forage crops represents a second generation of biomass feedstock for conversion into energy-related end products. Some of the most extensively studied species for cellulosic feedstock production include forages such as switchgrass (Panicum virgatum L., reed canarygrass (Phalaris arundinacea L., and alfalfa (Medicago sativa L.. An advantage of using forages as bioenergy crops is that farmers are familiar with their management and already have the capacity to grow, harvest, store, and transport them. Forage crops offer additional flexibility in management because they can be used for biomass or forage and the land can be returned to other uses or put into crop rotation. Estimates indicate about 22.3 million ha of cropland, idle cropland, and cropland pasture will be needed for biomass production in 2030. Converting these lands to large scale cellulosic energy farming could push the traditional forage-livestock industry to ever more marginal lands. Furthermore, encouraging bioenergy production from marginal lands could directly compete with forage-livestock production.

  18. Mineralization of soil organic matter in biochar amended agricultural landscape

    Science.gov (United States)

    Chintala, R.; Clay, D. E.; Schumacher, T. E.; Kumar, S.; Malo, D. D.

    2015-12-01

    Pyrogenic biochar materials have been identified as a promising soil amendment to enhance climate resilience, increase soil carbon recalcitrance and achieve sustainable crop production. A three year field study was initiated in 2013 to study the impact of biochar on soil carbon and nitrogen storage on an eroded Maddock soil series - Sandy, Mixed, Frigid Entic Hapludolls) and deposition Brookings clay loam (Fine-Silty, Mixed, Superactive, Frigid Pachic Hapludolls) landscape positions. Three biochars produced from corn stover (Zea mays L.), Ponderosa pine (Pinus ponderosa Lawson and C. Lawson) wood residue, and switchgrass (Panicum virgatum L.) were incorporated at 9.75 Mg ha-1 rate (≈7.5 cm soil depth and 1.3 g/cm3 soil bulk density) with a rototiller. The changes in chemical fractionation of soil carbon (soluble C, acid hydrolyzable C, total C, and δ13 C) and nitrogen (soluble N, acid hydrolyzable N, total N, and δ14 N) were monitored for two soil depths (0-7.5 and 7.5 - 15 cm). Soluble and acid hydrolyzable fractions of soil C and N were influenced by soil series and were not significantly affected by incorporation of biochars. Based on soil and plant samples to be collected in the fall of 2015, C and N budgets are being developed using isotopic and non-isotopic techniques. Laboratory studies showed that the mean residence time for biochars used in this study ranged from 400 to 666 years. Laboratory and field studies will be compared in the presentation.

  19. Dissolution, sorption, and phytoremediation of IMX-101 explosive formulation constituents: 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO), and nitroguanidine.

    Science.gov (United States)

    Richard, Thomas; Weidhaas, Jennifer

    2014-09-15

    The insensitive munition, IMX-101 approved for use in the USA, contains 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO), and nitroguanidine (NQ) and is designed to be less sensitive to shock and sympathetic detonation. Given the estimated future use of IMX-101, an understanding of IMX-101 constituent attenuation mechanisms on testing and training ranges is needed. Studies were conducted to determine (1) the rates of IMX-101 fragment dissolution during simulated rainfall, (2) DNAN and NTO soil sorption coefficients, (3) ability of grasses to germinate in and phytoremediate IMX-101 contaminated soil, and (4) effect of the addition of IMX-101 degrading enrichment cultures on phytoremediation. The IMX-101 particles were found to dissolve slowly under simulated rainfall conditions with NQ and NTO dissolving first, leaving DNAN crystals. DNAN and NTO sorption to soils fit Freundlich isotherms and limited desorption was observed. DNAN and NQ were shown to be taken up into the roots and shoots of a mixture of big bluestem grass (Andropogon gerardii), Nash Indiangrass (Sorghastrum nutans), and switchgrass (Panicum virgatum) during phytoremediation of soils contaminated with up to 50 mg kg(-1) IMX-101. Complete degradation of IMX-101 to below detection limits occurred over 225 days. The addition of an IMX-101 degrading enrichment culture to the treatments significantly increased the root and shoot mass. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Scenarios of bioenergy development impacts on regional groundwater withdrawals

    Science.gov (United States)

    Uden, Daniel R.; Allen, Craig R.; Mitchell, Rob B.; Guan, Qingfeng; McCoy, Tim D.

    2013-01-01

    Irrigation increases agricultural productivity, but it also stresses water resources (Huffaker and Hamilton 2007). Drought and the potential for drier conditions resulting from climate change could strain water supplies in landscapes where human populations rely on finite groundwater resources for drinking, agriculture, energy, and industry (IPCC 2007). For instance, in the North American Great Plains, rowcrops are utilized for livestock feed, food, and bioenergy production (Cassman and Liska 2007), and a large portion is irrigated with groundwater from the High Plains aquifer system (McGuire 2011). Under projected future climatic conditions, greater crop water use requirements and diminished groundwater recharge rates could make rowcrop irrigation less feasible in some areas (Rosenberg et al. 1999; Sophocleous 2005). The Rainwater Basin region of south central Nebraska, United States, is an intensively farmed and irrigated Great Plains landscape dominated by corn (Zea mays L.) and soybean (Glycine max L.) production (Bishop and Vrtiska 2008). Ten starch-based ethanol plants currently service the region, producing ethanol from corn grain (figure 1). In this study, we explore the potential of switchgrass (Panicum virgatum L.), a drought-tolerant alternative bioenergy feedstock, to impact regional annual groundwater withdrawals for irrigation under warmer and drier future conditions. Although our research context is specific to the Rainwater Basin and surrounding North American Great Plains, we believe the broader research question is internationally pertinent and hope that this study simulates similar research in other areas.

  1. Emission of CO2 from energy crop production

    International Nuclear Information System (INIS)

    Turhollow, A.F.

    1991-01-01

    The production of cellulosic energy crops (e.g., short rotation woody crops and herbaceous crops) make a net contribution of CO 2 to the atmosphere to the extent that fossil-fuel based inputs are used in their production. The CO 2 released from the use of the biomass is merely CO 2 that has recently been removed from the atmosphere by the plant growth process. Fossil inputs used in the production of energy corps include energy invested in fertilizers and pesticides, and petroleum fuels used for machinery operation such as site preparation, weed control, harvesting, and hauling. Fossil inputs used come from petroleum, natural gas, and electricity derived from fossil sources. No fossil inputs for the capital used to produce fertilizers, pesticides, or machinery is calculated in this analysis. In this paper calculations are made for the short rotation woody crop hybrid poplar (Populus spp.), the annual herbaceous crop sorghum (Sorghum biocolor [L.] Moench), and the perennial herbaceous crop switchgrass (Panicum virgatum L.). For comparison purposes, emissions of CO 2 from corn (Zea mays L.) are calculated

  2. An exploration of common reed (Phragmites australis bioenergy potential in North America

    Directory of Open Access Journals (Sweden)

    R. Vaičekonytė

    2014-10-01

    Full Text Available In North America, reed (Phragmites australis is typically considered to be a weed although it provides important ecosystem services. Small, sparse, patchy or mixed reedbeds are more suitable as habitat for many species than extensive dense reedbeds, whose habitat functions can be enhanced by the selective removal of biomass. We propose that above-ground reed biomass could be harvested for bioenergy, at the same time improving habitat for biodiversity by thinning or fragmenting the more extensive reedbeds. Biofuel pellets manufactured from reeds harvested at Montréal (Canada had moisture content 6.4 %, energy content 16.9 kJ g-1 (dry mass, ash content 3.44 %, and chloride content 1962 ppm. Thus, reed as a material for fuel pellet manufacture is similar to switchgrass (Panicum virgatum, which is commonly cultivated for that purpose and requires higher inputs than harvested wild reed. We discuss these findings in the context of environmental considerations and conclude that the bioenergy potential of reed could most expediently be realised in North America by combining material harvested from the widespread spontaneously occurring reedbeds with organic waste from other sources to create mixed biofuels. However, reeds with high levels of chlorine, sulphur or metals should not be burned to avoid air pollution or equipment damage unless these problems are mitigated by means of appropriate season of harvest, equipment, combustion regime, or use of a mixed feedstock.

  3. Decreasing Fertilizer use by Optimizing Plant-microbe Interactions for Sustainable Supply of Nitrogen for Bioenergy Crops

    Science.gov (United States)

    Schicklberger, M. F.; Huang, J.; Felix, P.; Pettenato, A.; Chakraborty, R.

    2013-12-01

    Nitrogen (N) is an essential component of DNA and proteins and consequently a key element of life. N often is limited in plants, affecting plant growth and productivity. To alleviate this problem, tremendous amounts of N-fertilizer is used, which comes at a high economic price and heavy energy demand. In addition, N-fertilizer also significantly contributes to rising atmospheric greenhouse gas concentrations. Therefore, the addition of fertilizer to overcome N limitation is highly undesirable. To explore reduction in fertilizer use our research focuses on optimizing the interaction between plants and diazotrophic bacteria, which could provide adequate amounts of N to the host-plant. Therefore we investigated the diversity of microbes associated with Tobacco (Nicotiana tabacum) and Switchgrass (Panicum virgatum), considered as potential energy crop for bioenergy production. Several bacterial isolates with representatives from Alphaproteobacteria, Gammaproteobacteria, Actinobacteria, Bacteriodetes and Bacilli were obtained from the roots, leaves, rhizoplane and rhizosphere of these plants. Majority of these isolates grew best with simple sugars and small organic acids. As shown by PCR amplification of nifH, several of these isolates are potential N2-fixing bacteria. We investigated diazotrophs for their response to elevated temperature and salinity (two common climate change induced stresses found on marginal lands), their N2-fixing ability, and their response to root exudates (which drive microbial colonization of the plant). Together this understanding is necessary for the development of eco-friendly, economically sustainable energy crops by decreasing their dependency on fertilizer.

  4. LYOPHILIZATION EFFECT ON PRODUCTIVITY OF BUTANOL-PRODUCING STRAINS

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    O. O. Tigunova

    2016-10-01

    Full Text Available Investigation of lyophilization effect on the productivity of butanol-producing strains was the aim of our research. For this purpose we used butanol-producing strains; technical glycerol; biomass of switchgrass Panicum virgatum L. Lyophilization was performed using a lyophilization-drying. The effect of the protective medium on residual moisture of freezedrying cultures suspensions depending on the concentration of glucose and sucrose was studed. It was shown that the lowest residual moisture was attained by using glucose and sucrose in amount of 10% and if the samples of freeze-drying bacteria had been saved for one month at 4 οC the productivity did not decrease. As temperature preservation was increased the productivity of the cultures was gradually decreased and it was greatly reduced at 30 οC. So the protective medium composition was optimized for lyophilization of butanol-producing strains as follows: sucrose 10.0%; gelatin 10.0%; agar 0.02%. It was shown that the preservation of samples of freeze-drying bacteria for six months at a temperature of 4 οC did not affect the productivity of strains. It was found that cultures could use glycerol as a carbon source for butanol accumulation before lyophilization.

  5. Grass and forb species for revegetation of mixed soil-lignite overburden in East Central Texas

    Energy Technology Data Exchange (ETDEWEB)

    Skousen, J.G.; Call, C.A. (West Virginia University, Morgantown, WV (USA). Division of Plant and Soil Sciences)

    Ten grasses and seven forbs were seeded into mixed soil-lignite overburden in the Post Oak Savannah region of Texas and monitored for establishment and growth over a 3-year period without fertilization. Buffelgrass (Cenchrus ciliaris), green sprangletop (Leptochloa dubia), switchgrass (Panicum virgatum), and kleingrass (P. coloratum) developed monotypic stands with sufficent density, aerial cover, and aboveground biomass to stabilize the mixed soil-lignite overburden surface by the end of the first growing season. Plant mortality eliminated buffelgrass and green sprangletop stands by the end of the third growing season. Indiangrass (Sorghastrum nutans) developed a satisfactory stand by the end of the third growing season, while Oldworld bluestem (Bothriochloa X Dicanthium), yellow bluestem (Bothriochloa ischaemum), and sideoats grama (Bouteloua curtipendula) established at a slower rate. Cover and biomass measurements from an adjacent, unfertilized stand of Coastal bermudagrass (Cynodon dactylon) were compared with those of seeded grasses throughout the study. Partidge pea (Cassia fasciculata) established rapidly and had the greatest cover and biomass of all seeded forbs by the end of the first growing season. Sericea lespedeza (Lespedeza cuneata), Illinois bundleflower (Desmanthus illinoensis), and western indigo (Indigofera miniata) developed adequate stands for surface stabilization by the end of the third growing season, while faseanil indigo (Indigofera suffruticosa), virgata lespedeza (Lespedeza virgata), and awnless bushsunflower (Simsia calva) showed slower establishment. 27 refs., 3 tabs.

  6. Molecular characterization of biochars and their influence on microbiological properties of soil.

    Science.gov (United States)

    Chintala, Rajesh; Schumacher, Thomas E; Kumar, Sandeep; Malo, Douglas D; Rice, James A; Bleakley, Bruce; Chilom, Gabriela; Clay, David E; Julson, James L; Papiernik, Sharon K; Gu, Zheng Rong

    2014-08-30

    The tentative connection between the biochar surface chemical properties and their influence on microbially mediated mineralization of C, N, and S with the help of enzymes is not well established. This study was designed to investigate the effect of different biomass conversion processes (microwave pyrolysis, carbon optimized gasification, and fast pyrolysis using electricity) on the composition and surface chemistry of biochar materials produced from corn stover (Zea mays L.), switchgrass (Panicum virgatum L.), and Ponderosa pine wood residue (Pinus ponderosa Lawson and C. Lawson) and determine the effect of biochars on mineralization of C, N, and S and associated soil enzymatic activities including esterase (fluorescein diacetate hydrolase, FDA), dehydrogenase (DHA), β-glucosidase (GLU), protease (PROT), and aryl sulfatase (ARSUL) in two different soils collected from footslope (Brookings) and crest (Maddock) positions of a landscape. Chemical properties of biochar materials produced from different batches of gasification process were fairly consistent. Biochar materials were found to be highly hydrophobic (low H/C values) with high aromaticity, irrespective of biomass feedstock and pyrolytic process. The short term incubation study showed that biochar had negative effects on microbial activity (FDA and DHA) and some enzymes including β-glucosidase and protease. Published by Elsevier B.V.

  7. Perennial Forages as Second Generation Bioenergy Crops

    Science.gov (United States)

    Sanderson, Matt A.; Adler, Paul R.

    2008-01-01

    The lignocellulose in forage crops represents a second generation of biomass feedstock for conversion into energy-related end products. Some of the most extensively studied species for cellulosic feedstock production include forages such as switchgrass (Panicum virgatum L.), reed canarygrass (Phalaris arundinacea L.), and alfalfa (Medicago sativa L.). An advantage of using forages as bioenergy crops is that farmers are familiar with their management and already have the capacity to grow, harvest, store, and transport them. Forage crops offer additional flexibility in management because they can be used for biomass or forage and the land can be returned to other uses or put into crop rotation. Estimates indicate about 22.3 million ha of cropland, idle cropland, and cropland pasture will be needed for biomass production in 2030. Converting these lands to large scale cellulosic energy farming could push the traditional forage-livestock industry to ever more marginal lands. Furthermore, encouraging bioenergy production from marginal lands could directly compete with forage-livestock production. PMID:19325783

  8. Prairies Thrive Where Row Crops Drown: A Comparison of Yields in Upland and Lowland Topographies in the Upper Midwest US

    Directory of Open Access Journals (Sweden)

    Adam C. von Haden

    2016-05-01

    Full Text Available Cellulosic biofuel production is expected to increase in the US, and the targeted establishment of biofuel agriculture in marginal lands would reduce competition between biofuels and food crops. While poorly drained, seasonally saturated lowland landscape positions are marginal for production of row crops and switchgrass (Panicum virgatum L., it is unclear whether species-diverse tallgrass prairie yield would suffer similarly in saturated lowlands. Prairie yields typically increase as graminoids become more dominant, but it is uncertain whether this trend is due to greater aboveground net primary productivity (ANPP or higher harvest efficiency in graminoids compared to forbs. Belowground biomass, a factor that is important to ecosystem service provisioning, is reduced when switchgrass is grown in saturated lowlands, but it is not known whether the same is true in species-diverse prairie. Our objectives were to assess the effect of topography on yields and live belowground biomass in row crops and prairie, and to determine the mechanisms by which relative graminoid abundance influences tallgrass prairie yield. We measured yield, harvest efficiency, and live belowground biomass in upland and lowland landscape positions within maize silage (Zea mays L., winter wheat (Triticum aestivum L., and restored tallgrass prairie. Maize and winter wheat yields were reduced by more than 60% in poorly drained lowlands relative to well-drained uplands, but diverse prairie yields were equivalent in both topographic settings. Prairie yields increased by approximately 45% as the relative abundance of graminoids increased from 5% to 95%. However, this trend was due to higher harvest efficiency of graminoids rather than greater ANPP compared to forbs. In both row crops and prairie, live belowground biomass was similar between upland and lowland locations, indicating consistent biomass nutrient sequestration potential and soil organic matter inputs between topographic

  9. Strategies for enhancing the effectiveness of metagenomic-based enzyme discovery in lignocellulytic microbial communities

    Energy Technology Data Exchange (ETDEWEB)

    DeAngelis, K.M.; Gladden, J.G.; Allgaier, M.; D' haeseleer, P.; Fortney, J.L.; Reddy, A.; Hugenholtz, P.; Singer, S.W.; Vander Gheynst, J.; Silver, W.L.; Simmons, B.; Hazen, T.C.

    2010-03-01

    Producing cellulosic biofuels from plant material has recently emerged as a key U.S. Department of Energy goal. For this technology to be commercially viable on a large scale, it is critical to make production cost efficient by streamlining both the deconstruction of lignocellulosic biomass and fuel production. Many natural ecosystems efficiently degrade lignocellulosic biomass and harbor enzymes that, when identified, could be used to increase the efficiency of commercial biomass deconstruction. However, ecosystems most likely to yield relevant enzymes, such as tropical rain forest soil in Puerto Rico, are often too complex for enzyme discovery using current metagenomic sequencing technologies. One potential strategy to overcome this problem is to selectively cultivate the microbial communities from these complex ecosystems on biomass under defined conditions, generating less complex biomass-degrading microbial populations. To test this premise, we cultivated microbes from Puerto Rican soil or green waste compost under precisely defined conditions in the presence dried ground switchgrass (Panicum virgatum L.) or lignin, respectively, as the sole carbon source. Phylogenetic profiling of the two feedstock-adapted communities using SSU rRNA gene amplicon pyrosequencing or phylogenetic microarray analysis revealed that the adapted communities were significantly simplified compared to the natural communities from which they were derived. Several members of the lignin-adapted and switchgrass-adapted consortia are related to organisms previously characterized as biomass degraders, while others were from less well-characterized phyla. The decrease in complexity of these communities make them good candidates for metagenomic sequencing and will likely enable the reconstruction of a greater number of full length genes, leading to the discovery of novel lignocellulose-degrading enzymes adapted to feedstocks and conditions of interest.

  10. Accelerated development in Johnsongrass seedlings (Sorghum halepense suppresses the growth of native grasses through size-asymmetric competition.

    Directory of Open Access Journals (Sweden)

    Susanne Schwinning

    Full Text Available Invasive plant species often dominate native species in competition, augmenting other potential advantages such as release from natural enemies. Resource pre-emption may be a particularly important mechanism for establishing dominance over competitors of the same functional type. We hypothesized that competitive success of an exotic grass against native grasses is mediated by establishing an early size advantage. We tested this prediction among four perennial C4 warm-season grasses: the exotic weed Johnsongrass (Sorghum halepense, big bluestem (Andropogon gerardii, little bluestem (Schizachyrium scoparius and switchgrass (Panicum virgatum. We predicted that a the competitive effect of Johnsongrass on target species would be proportional to their initial biomass difference, b competitive effect and response would be negatively correlated and c soil fertility would have little effect on competitive relationships. In a greenhouse, plants of the four species were grown from seed either alone or with one Johnsongrass neighbor at two fertilizer levels and periodically harvested. The first two hypotheses were supported: The seedling biomass of single plants at first harvest (50 days after seeding ranked the same way as the competitive effect of Johnsongrass on target species: Johnsongrass < big bluestem < little bluestem/switchgrass, while Johnsongrass responded more strongly to competition from Johnsongrass than from native species. At final harvest, native plants growing with Johnsongrass attained between 2-5% of their single-plant non-root biomass, while Johnsongrass growing with native species attained 89% of single-plant non-root biomass. Fertilization enhanced Johnsongrass' competitive effects on native species, but added little to the already severe competitive suppression. Accelerated early growth of Johnsongrass seedlings relative to native seedlings appeared to enable subsequent resource pre-emption. Size-asymmetric competition and resource

  11. Will energy crop yields meet expectations?

    International Nuclear Information System (INIS)

    Searle, Stephanie Y.; Malins, Christopher J.

    2014-01-01

    Expectations are high for energy crops. Government policies in the United States and Europe are increasingly supporting biofuel and heat and power from cellulose, and biomass is touted as a partial solution to energy security and greenhouse gas mitigation. Here, we review the literature for yields of 5 major potential energy crops: Miscanthus spp., Panicum virgatum (switchgrass), Populus spp. (poplar), Salix spp. (willow), and Eucalyptus spp. Very high yields have been achieved for each of these types of energy crops, up to 40 t ha −1  y −1 in small, intensively managed trials. But yields are significantly lower in semi-commercial scale trials, due to biomass losses with drying, harvesting inefficiency under real world conditions, and edge effects in small plots. To avoid competition with food, energy crops should be grown on non-agricultural land, which also lowers yields. While there is potential for yield improvement for each of these crops through further research and breeding programs, for several reasons the rate of yield increase is likely to be slower than historically has been achieved for cereals; these include relatively low investment, long breeding periods, low yield response of perennial grasses to fertilizer, and inapplicability of manipulating the harvest index. Miscanthus × giganteus faces particular challenges as it is a sterile hybrid. Moderate and realistic expectations for the current and future performance of energy crops are vital to understanding the likely cost and the potential of large-scale production. - Highlights: • This review covers Miscanthus, switchgrass, poplar, willow, and Eucalyptus. • High yields of energy crops are typically from small experimental plots. • Field scale yields are lower due to real world harvesting losses and edge effects. • The potential for yield improvement of energy crops is relatively limited. • Expectations must be realistic for successful policies and commercial production

  12. Bio-energy feedstock yields and their water quality benefits in Mississippi

    Energy Technology Data Exchange (ETDEWEB)

    Parajuli, Prem B.

    2011-08-10

    Cellulosic and agricultural bio-energy crops can, under careful management, be harvested as feedstock for bio-fuels production and provide environmental benefits. However, it is required to quantify their relative advantages in feedstock production and water quality. The primary objective of this research was to evaluate potential feedstock yield and water quality benefit scenarios of bioenergy crops: Miscanthus (Miscanthus-giganteus), Switchgrass (Panicum virgatum), Johnsongrass (Sorghum halepense), Alfalfa (Medicago sativa L.), Soybean {Glycine max (L.) Merr.}, and Corn (Lea mays) in the Upper Pearl River watershed (UPRW), Mississippi using a Soil and Water Assessment Tool (SWAT). The SWAT model was calibrated (January 1981 to December 1994) and validated (January 1995 to September 2008) using monthly measured stream flow data. The calibrated and validated model determined good to very good performance for stream flow prediction (R2 and E from 0.60 to 0.86). The RMSE values (from 14 m3 s-1 to 37 m3 s-1) were estimated at similar levels of errors during model calibration and validation. The long-term average annual potential feedstock yield as an alternative energy source was determined the greatest when growing Miscanthus grass (373,849 Mg) as followed by Alfalfa (206,077 Mg), Switchgrass (132,077 Mg), Johnsongrass (47,576 Mg), Soybean (37,814 Mg), and Corn (22,069 Mg) in the pastureland and cropland of the watershed. Model results determined that average annual sediment yield from the Miscanthus grass scenario determined the least (1.16 Mg/ha) and corn scenario the greatest (12.04 Mg/ha). The SWAT model simulated results suggested that growing Miscanthus grass in the UPRW would have the greatest potential feedstock yield and water quality benefits.

  13. Evaluating environmental consequences of producing herbaceous crops for bioenergy

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, S.B.

    1995-12-31

    The environmental costs and benefits of producing bioenergy crops can be measured both in kterms of the relative effects on soil, water, and wildlife habitat quality of replacing alternate cropping systems with the designated bioenergy system, and in terms of the quality and amount of energy that is produced per unit of energy expended. While many forms of herbaceous and woody energy crops will likely contribute to future biofuels systems, The Dept. of Energy`s Biofuels Feedstock Development Program (BFDP), has chosen to focus its primary herbaceous crops research emphasis on a perennial grass species, switchgrass (Panicum virgatum), as a bioenergy candidate. This choice was based on its high yields, high nutrient use efficiency, and wide geographic distribution, and also on its poistive environmental attributes. The latter include its positive effects on soil quality and stabiity, its cover value for wildlife, and the lower inputs of enerty, water, and agrochemicals required per unit of energy produced. A comparison of the energy budgets for corn, which is the primary current source of bioethanol, and switchgrass reveals that the efficiency of energy production for a perennial grass system can exceed that for an energy intensive annual row crop by as much as 15 times. In additions reductions in CO{sub 2} emission, tied to the energetic efficiency of producing transportation fuels, are very efficient with grasses. Calculated carbon sequestration rates may exceed those of annual crops by as much as 20--30 times, due in part to carbon storage in the soil. These differences have major implications for both the rate and efficiency with which fossil energy sources can be replaced with cleaner burning biofuels.

  14. Evaluating environmental consequences of producing herbaceous crops for bioenergy

    International Nuclear Information System (INIS)

    McLaughlin, S.B.

    1995-01-01

    The environmental costs and benefits of producing bioenergy crops can be measured both in kterms of the relative effects on soil, water, and wildlife habitat quality of replacing alternate cropping systems with the designated bioenergy system, and in terms of the quality and amount of energy that is produced per unit of energy expended. While many forms of herbaceous and woody energy crops will likely contribute to future biofuels systems, The Dept. of Energy's Biofuels Feedstock Development Program (BFDP), has chosen to focus its primary herbaceous crops research emphasis on a perennial grass species, switchgrass (Panicum virgatum), as a bioenergy candidate. This choice was based on its high yields, high nutrient use efficiency, and wide geographic distribution, and also on its poistive environmental attributes. The latter include its positive effects on soil quality and stabiity, its cover value for wildlife, and the lower inputs of enerty, water, and agrochemicals required per unit of energy produced. A comparison of the energy budgets for corn, which is the primary current source of bioethanol, and switchgrass reveals that the efficiency of energy production for a perennial grass system can exceed that for an energy intensive annual row crop by as much as 15 times. In additions reductions in CO 2 emission, tied to the energetic efficiency of producing transportation fuels, are very efficient with grasses. Calculated carbon sequestration rates may exceed those of annual crops by as much as 20--30 times, due in part to carbon storage in the soil. These differences have major implications for both the rate and efficiency with which fossil energy sources can be replaced with cleaner burning biofuels

  15. Integrated omics analyses reveal the details of metabolic adaptation of Clostridium thermocellum to lignocellulose-derived growth inhibitors released during the deconstruction of switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Poudel, Suresh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Giannone, Richard J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rodriguez, Jr., Miguel [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Raman, Babu [Dow Chemical Company, Midland, MI (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Martin, Madhavi Z. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Engle, Nancy L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mielenz, Jonathan R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nookaew, Intawat [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Arkansas, Fayetteville, AR (United States); Brown, Steven D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Tschaplinski, Timothy J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ussery, David W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Arkansas, Fayetteville, AR (United States); Hettich, Robert L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)

    2017-01-10

    Clostridium thermocellum is capable of solubilizing and converting lignocellulosic biomass into ethanol. Though much of the work-to-date has centered on characterizing the organism s metabolism during growth on model cellulosic substrates, such as cellobiose, Avicel, or filter paper, it is vitally important to understand it metabolizes more complex, lignocellulosic substrates to identify relevant industrial bottlenecks that could undermine efficient biofuel production. To this end, we have examined a time course progression of C. thermocellum grown on switchgrass to assess the metabolic and protein changes that occur during the conversion of plant biomass to ethanol. The most striking feature of the metabolome was the observed accumulation of long-chain, branched fatty acids over time, implying an adaptive restructuring of C. thermocellum s cellular membrane as the culture progresses. This is likely a response to the gradual build-up of lignocellulose-derived inhibitory compounds detected as the organism deconstructs the switchgrass to access the embedded cellulose and includes 4-hydroxybenzoic acid, vanillic acid, ferulic acid, p-coumaric acid and vanillin. Corroborating the metabolomics data, proteomic analysis revealed a corresponding time-dependent increase in enzymes involved in the interconversion of branched amino acids valine, leucine and isoleucine to iso- and anteiso-fatty acid precursors. Furthermore, the metabolic accumulation of hemicellulose-derived sugars and sugar-alcohols concomitant with increased abundance of enzymes involved in C5 sugar metabolism / the pentose phosphate pathway, indicate that C. thermocellum either shifts glycolytic intermediates to alternate pathways to modulate overall carbon flux or is simply a response to C5 sugar metabolite pools that build during lignocellulose deconstruction.

  16. Lignocellulose fermentation and residual solids characterization for senescent switchgrass fermentation by Clostridium thermocellum in the presence and absence of continuous in situ ball-milling

    Energy Technology Data Exchange (ETDEWEB)

    Balch, Michael L.; Holwerda, Evert K.; Davis, Mark F.; Sykes, Robert W.; Happs, Renee M.; Kumar, Rajeev; Wyman, Charles E.; Lynd, Lee R.

    2017-04-12

    Milling during lignocellulosic fermentation, henceforth referred to as cotreatment, is investigated as an alternative to thermochemical pretreatment as a means of enhancing biological solubilization of lignocellulose. We investigate the impact of milling on soluble substrate fermentation by Clostridium thermocellum with comparison to yeast, document solubilization for fermentation of senescent switchgrass with and without ball milling, and characterize residual solids. Soluble substrate fermentation by C. thermocellum proceeded readily in the presence of continuous ball milling but was completely arrested for yeast. Total fractional carbohydrate solubilization achieved after fermentation of senescent switchgrass by C. thermocellum for 5 days was 0.45 without cotreatment or pretreatment, 0.81 with hydrothermal pretreatment (200 degrees C, 15 minutes, severity 4.2), and 0.88 with cotreatment. Acetate and ethanol were the main fermentation products, and were produced at similar ratios with and without cotreatment. Analysis of solid residues was undertaken using molecular beam mass spectrometry (PyMBMS) and solid-state nuclear magnetic resonance spectroscopy (NMR) in order to provide insight into changes in plant cell walls during processing via various modes. The structure of lignin present in residual solids remaining after fermentation with cotreatment appeared to change little, with substantially greater changes observed for hydrothermal pretreatment - particularly with respect to formation of C-C bonds. The observation of high solubilization with little apparent modification of the residue is consistent with cotreatment enhancing solubilization primarily by increasing the access of saccharolytic enzymes to the feedstock, and C. thermocellum being able to attack all the major linkages in cellulosic biomass provided that these linkages are accessible.

  17. Produção e composição químico-bromatológica do capim-furachão (Panicum repens L. sob adubação e diferentes idades de corte Production and chemical composition of furachão grass (Panicum repens L. under fertilization and different cutting ages

    Directory of Open Access Journals (Sweden)

    Rogério da Silva Aguiar

    2000-04-01

    Full Text Available O objetivo deste trabalho foi avaliar a produção de matéria seca (MS e a composição químico-bromatológica do capim-furachão (Panicum repens L. em diferentes idades de corte (15, 30, 45, 60 e 75 dias, na presença e ausência de adubação. Para as análises de produção e composição química, utilizou-se delineamento em blocos casualizados, em um fatorial 5 x 2 (cinco idades de corte e dois níveis de adubação, com três repetições. A adubação proporcionou aumento na produção e redução nos teores de MS. Os teores de proteína bruta (PB foram reduzidos com o avanço da idade da gramínea. Aos 60 dias, encontraram-se produções de 541,87 kg/ha de PB e 5343,92 kg/ha de MS e teores médios de FDN e FDA de 69,70 e 34,25% na MS, respectivamente. As idades de corte influíram nos teores de FDN e FDA, mas a adubação não influenciou os teores de FDN. Os teores de Ca não diferiram na presença ou ausência de adubação, com média de 0,13% na MS, e aumentaram com a idade de corte. Os teores de P diminuíram com o avanço da idade da gramínea, sendo o maior valor 0,22% na MS, na condição sem adubo.The objective of this work was to evaluate the dry matter (DM yield and chemical composition of furachão grass (Panicum repens L. at different cutting ages (15, 30, 45, 60 and 75 days, with and without fertilization. For the yield analysis and chemical aanalysis composition, a completely randomized block design in a 5 x 2 factorial arrangement (cutting ages and fertilization levels, with three replicates, was used. Fertilization increased DM produced and reduction in the DM contents. The crude protein (CP contents decreased as the cutting ages increased. At 60 days, productions of 541,87 kg/ha CP and 5343.92 kg/ha DM and average neutral detergent fiber (NDF and acid detergent fiber (ADF contents of 69.7 and basis 34.25% in DM respectively were observed. The cutting ages affected the NDF and ADF average contents, but fertilization

  18. Avaliação de três cultivares de Panicum maximum Jacq. sob pastejo: composição da dieta, consumo de matéria seca e ganho de peso animal Evaluation of three varieties of Panicum maximum Jacq. under grazing: diet composition, dry matter intake and animal weight gain

    Directory of Open Access Journals (Sweden)

    Patrícia Amarante Brâncio

    2003-10-01

    Full Text Available Três cultivares de Panicum maximum Jacq. submetidos a pastejo rotativo foram avaliados ao longo do ano, antes e após o período de pastejo, quanto à composição botânica e química da dieta, consumo de matéria seca e ganho de peso animal. Os tratamentos constituíram em: 1 cv. Tanzânia + 50 kg/ha de N, 2 cv. Tanzânia + 100 kg/ha de N, 3 cv. Mombaça + 50 kg/ha de N, e 4 cv. Massai + 50 kg/ha de N. As dietas selecionadas pelos animais na cv. Massai tenderam a apresentar os menores valores de digestibilidade e proteína bruta e os maiores de fibra em detergente neutro, enquanto na cv. Mombaça as dietas continham, em geral, maiores teores de sílica. Os animais selecionaram, em média, 92,4% de folhas verdes, independentemente do tratamento e da época de amostragem. Os animais consumiram semelhantes quantidades de forragem nos diversos tratamentos, apresentando, em média, consumos de 1,9; 2,8; 3,4; e 2,3 kgMS/100kgPV, respectivamente, em junho, setembro e novembro de 1998 e março de 1999. Os piores resultados quanto ao ganho de peso por animal foram verificados na cv. Massai, mas, devido a sua alta capacidade de suporte na época chuvosa, superou a cv. Mombaça e cv. Tanzânia + 50 kg/ha de N, em termos de ganho de peso por área. A participação de folhas, a altura do pasto, o teor de proteína bruta da dieta selecionada pelos animais e o tamanho de bocado foram os fatores que mais influenciaram positivamente o ganho de peso animal.Three varieties of Panicum maximum Jacq. were evaluated by measuring the botanical and chemical composition of the diet, and the dry matter intake and weight gain of the animal under rotational grazing, before and after a period of grazing. The treatments were: 1 v. Tanzânia + 50 kg N/ha, 2 v. Tanzânia + 100 kg N/ha, 3 v. Mombaça + 50 kg N/ha, and 4 v. Massai + 50 kg N/ha. Of the diets selected by the animals, v. Massai tended to show lower values for digestibility and crude protein, and higher values

  19. Beef cattle supplementation maintained on pasture of “Panicum maximum” cv. Tanzânia-1 on rainy season Suplementação de bovinos de corte mantidos em pastagem de "Panicum maximum" cv. Tanzânia-1 no período das águas

    Directory of Open Access Journals (Sweden)

    João Garcia Caramori Júnior

    2008-06-01

    Full Text Available The objective with this study was to evaluate the effect of different supplementation levels in Nelore bulls during rainy season. It was used 32 Nelore bulls with 18 months old and 374 Kg of body live weight (LW, which were submitted to one of the four treatments: T1, pasture with mineral salt; T2, pasture plus 0.2% of LW of concentrate ration; T3, pasture plus 0.4% of LW with concentrate ration; T4, pasture plus 0.6% of LW with concentrate ration. Animals were kept on pastures of Panicum maximum cv. Tanzânia-1 divided in four fields with 3 hectares, for each group. Supplements were constituted of mineral salt, corn meal, soybean meal, soybean hulls and urea. Animals were weighed at the beginning and every 28 days to determinate average daily weight gain (ADG, and kept under rotational grazing and pasture mass availability was evaluated. ADG was not influenced by the levels of supplement. The use of Tanzania grass with adequate mass pasture availability allowed higher performance of the beef cattle in rainy season, that presented ADG of 0.99kg/animal.Objetivou-se com este trabalho avaliar o efeito de diferentes níveis de suplementação sobre o desempenho de touros Nelore PO, durante o período das águas. Foram utilizados 32 animais de 18 meses de idade, com peso vivo médio inicial de 374 Kg, os quais foram divididos em quatro grupos e submetidos aos seguintes tratamentos experimentais avaliados: mistura mineral (T1; suplementação com concentrado na base de 0,2% do peso vivo (T2; suplementação com concentrado de 0,4% do PV (T3 e suplementação com concentrado de 0,6% do PV (T4. Os animais foram mantidos durante 84 dias em pastagem de Panicum maximum cv. Tanzânia -1, dividida em quatro piquetes de 3 ha , de modo que cada um dos grupos de animais fosse mantido de acordo com o tratamento utilizado. O concentrado foi composto de mistura mineral, fubá de milho, farelo de soja, casca de soja e uréia. Os animais foram pesados no início e a

  20. Descomposición de la hojarasca en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala (Lam de Wit cv. Cunningham: II. Influencia de los factores climáticos Litter decomposition in a silvopastoral system of Panicum maximum and Leucaena leucocephala (Lam de Wit cv. Cunningham: II. Influence of climatic factors

    Directory of Open Access Journals (Sweden)

    Saray Sánchez

    2009-12-01

    Full Text Available Con el objetivo de determinar la descomposición de la hojarasca en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala y su relación con algunos factores del clima, se realizó este experimento en la EEPF «Indio Hatuey». La descomposición de la hojarasca se determinó como la pérdida de biomasa a través del tiempo, con relación al peso inicial. Para el estudio de la dinámica de la descomposición se utilizó el método de bolsas de hojarasca (litter bags; se registró diariamente el comportamiento de la temperatura media, la humedad relativa, la precipitación y los días con lluvias, en la estación metereológica situada a 1 km del área experimental. Se utilizó el análisis de correlación y regresión para conocer la interrelación entre las variables y los modelos de mejor ajuste. Se consideró, como variables independientes, los factores climáticos estudiados, y como variable dependiente el porcentaje de biomasa perdida. De forma general, los resultados demostraron que el comportamiento de la descomposición de la hojarasca, tanto en la guinea como en la leucaena, estuvo relacionado con los factores climáticos que prevalecieron durante el período experimental y, por tanto, es posible explicar este proceso en ambos pastizales a partir de la acción conjunta de la temperatura, la humedad relativa y la precipitación.With the objective of determining the litter decomposition in a silvopastoral system of Panicum maximum and Leucaena leucocephala and its relationship to some climate factors, this trial was conducted at the EEPF «Indio Hatuey». Litter decomposition was determined as the loss of biomass through time, with regards to initial weight. For studying the decomposition dynamics the method of litter bags was used; the performance of mean temperature, relative humidity, rainfall and days with rain, was daily recorded at the meteorological station located 1 km away from the experimental area. . The

  1. Descomposición de la hojarasca en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala (Lam de Wit cv. Cunningham: I. Influencia de su composición química Litter decomposition in a silvopastoral system of Panicum maximum and Leucaena leucocephala (Lam de Wit cv. Cunningham: I. Influence of their chemical composition

    Directory of Open Access Journals (Sweden)

    Saray Sánchez

    2009-09-01

    Full Text Available Con el objetivo de determinar la descomposición de la hojarasca y su relación con la composición química de Panicum maximum y Leucaena leucocephala en un sistema silvopastoril, se realizó este experimento en la EEPF "Indio Hatuey". La descomposición de la hojarasca se determinó como la pérdida de biomasa a través del tiempo, con relación al peso inicial. Para el estudio de la dinámica de la descomposición se utilizó el método de bolsas de hojarasca (litter bags. En cada especie se presentó un patrón diferente de descomposición de la hojarasca; la tasa promedio de descomposición de la hojarasca en leucaena fue mayor que en la guinea. En ambas especies se encontró una rápida pérdida de peso durante los primeros 30 días y después el proceso fue más lento. Este comportamiento puede estar relacionado con la composición química de los pastos, pues el porcentaje de biomasa perdida de la hojarasca de L. leucocephala presentó una mayor correlación con las concentraciones del contenido celular, la relación lignina/nitrógeno, la celulosa y el Nt. Se observó una dependencia significativa y negativa de la hojarasca de P. maximum con las concentraciones de la FND y la hemicelulosa; mientras que se relacionó de forma positiva con las de N-FND y la relación lignina/nitrógenoWith the objective of determining the litter decomposition and its relationship to the chemical composition of Panicum maximum and Leucaena leucocephala in a silvopastoral system, this trial was conducted at the EEPF «Indio Hatuey». Litter decomposition was determined as biomass loss through time, with regards to initial weight. For studying the decomposition dynamics, the method of litter bags was used. In each species a different litter decomposition pattern appeared; the average litter decomposition rate was higher in leucaena than in Guinea grass. Rapid weight loss was found in both species during the first 30 days and afterwards the process was slower

  2. Descomposición de la hojarasca en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala (Lam de Wit cv. Cunningham: III. Influencia de la densidad y diversidad de la macrofauna asociada Litter decomposition in a silvopastoral system of Panicum maximum and Leucaena leucocephala (Lam de Wit cv. Cunningham: III. Influence of density and diversity of the associated macrofauna

    Directory of Open Access Journals (Sweden)

    Saray Sánchez

    2010-03-01

    Full Text Available Con el objetivo de determinar la descomposición de la hojarasca en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala y su relación con la densidad y la diversidad de la macrofauna asociada, se realizó este experimento en la EEPF «Indio Hatuey». Esta se determinó como la pérdida de biomasa a través del tiempo, con relación al peso inicial. Para el estudio de la dinámica de la descomposición se utilizó el método de bolsas de hojarasca (litter bags. Se escogieron al azar cuatro bolsas a los 30, 60, 90, 120, 150, 180 y 210 días de situadas en el pastizal. En cada fecha de recolección, a la hojarasca remanente de cada bolsa se le determinó la población de macrofauna (organismos con diámetro mayor que 2 mm mediante la separación manual, y se calculó el valor promedio de la densidad (individuos/m², así como la abundancia proporcional (% para cada taxón. Se utilizó el análisis de correlación y regresión para conocer la interrelación entre las variables y los modelos de mejor ajuste. De acuerdo con los resultados se concluye que las condiciones de humedad y temperatura que genera el árbol en este sistema, así como la calidad de su hojarasca, posibilitan la presencia de una diversa y estable fauna asociada a las bolsas, la cual influyó en el proceso de descomposición.The trial was conducted at the EEPF «Indio Hatuey» in order to determine the litter decomposition in a silvopastoral system of Panicum maximum and Leucaena leucocephala and its relation to the density and diversity of the associated macrofauna. It was determined as biomass loss through time, with regards to initial weight. For the study of the decomposition dynamics the litter bag method was used. Four bags were randomly chosen 30, 60, 90, 120, 150, 180 and 210 days after being placed in the pastureland. In each collection date, to the remnant litter of each bag, the macrofauna (organisms with diameter higher than 2 mm population was

  3. Avaliação de Três Cultivares de Panicum maximum Jacq. sob Pastejo: Composição Química e Digestibilidade da Forragem Evaluation of Three Cultivars of Panicum Maximum Jacq. under Grazing: Chemical Composition and in Vitro Organic Matter Digestibility

    Directory of Open Access Journals (Sweden)

    Patrícia Amarante Brâncio

    2002-07-01

    Full Text Available O estudo foi conduzido com o objetivo de estimar o valor nutritivo da MS de três cultivares de Panicum maximum Jacq. submetidas ao pastejo rotativo, através dos teores de proteína bruta, fibra em detergente neutro, fibra em detergente ácido, lignina, celulose, sílica e digestibilidade in vitro da matéria orgânica em amostras de folhas e colmos. Estudou-se, também, no cultivar Tanzânia, a adubação nitrogenada no final do período chuvoso, adicional à de manutenção comum às demais cultivares. As amostragens foram realizadas em junho, setembro e novembro de 1998 e março de 1999. Algumas diferenças entre tratamentos foram observadas, apresentando, em geral, menor valor nutritivo no cv. Massai, com menores teores de proteína bruta e digestibilidade e maiores teores de fibra em detergente neutro, fibra em detergente ácido e lignina tanto nas folhas, como nos colmos. Sua utilização como opção forrageira deve basear-se em outras características agronômicas. O cv. Mombaça apresentou, em geral, maiores teores de sílica e seu valor nutritivo não foi afetado pela adubação nitrogenada no final do período chuvoso, exceto pelo aumento no teor de proteína bruta e pela redução do conteúdo de lignina e sílica em março. O valor nutritivo dos colmos foi inferior ao das folhas. O início do período chuvoso foi, em geral, a época de maior valor nutritivo da forragem em todos os tratamentos.A study was conducted to evaluate three cultivars of Panicum maximum Jacq. under rotational grazing for the nutritive value,where the estimates of crude protein, neutral detergent fiber, acid detergent fiber, lignin, cellulose, silica, and in vitro digestibility of the organic material were performed in samples of leaves and stems. Additional nitrogen was applied in cv. Tanzania at the end of the rainny season. Samples were taken in June, September, and October 1998 and in March 1999. Some differences among treatments were observed. In general

  4. Cambios en la estructura, la población y la composición de 19 accesiones de Panicum maximum sometidas a pastoreo CIAT-184 Changes in the structure, population and composition of 19 Panicum maximum accessions under grazing conditions

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    R Machado

    2012-06-01

    Full Text Available Este trabajo tuvo como objetivo caracterizar los cambios y la tendencia de indicadores relacionados con la estructura, la población y la composición en 19 accesiones de Panicum maximum cuando fueron sometidas a condiciones de pastoreo simulado. Las rotaciones se hicieron cada 32-40 días en el periodo lluvioso y 60-70 días en el poco lluvioso, con intensidad de pastoreo de 80-135 UGM/ha/día (los dos primeros años y 120-160 UGM/ha/día (tercer año. Se utilizó un diseño de bloques al azar con tres repeticiones. Aunque en todos los tratamientos disminuyó la relación vástagos vivos/vástagos muertos, este cociente fue superior a uno, por lo que el ritmo de sustitución de vástagos fue favorable. En el 84,2% de los tratamientos se incrementó el número de macollas con relación a el estatus inicial. El porcentaje de arvenses aumentó con las rotaciones, pero ninguno de los tratamientos alcanzó un estado de deterioro avanzado. En este indicador se destacaron los tipos gigantes CIH-13, SIH-697, CIH-3, CC-1146 y SIH-10, con valores que variaron entre 4,6 y 14,1%, así como los tipos medianos CIH-15 y Tardío pequeño, con 10 y 12,3%, respectivamente. Se concluye que el germoplasma evaluado mostró valores adecuados, en función de los indicadores relacionados con la estructura de la macolla, la población y el porcentaje de invasión de las especies arvenses, aunque se identificó un alto contraste entre los tipos gigantes y medianos y dentro de estos grupos. Se sugiere analizar el resto de los indicadores productivos y con ello determinar los tipos más sobresalientes, sobre la base de los resultados en todos los indicadores incluidos.The objective of this work was to characterize the changes and trend of indicators related to the structure, population and composition in 19 Panicum maximum accessions under simulated grazing conditions. The rotations took place every 32-40 days in the rainy season and 60-70 days in the dry season, with

  5. Composição química do capim-Mombaça (Panicum maximum Jacq. cv. Mombaça adubado com diferentes fontes de fósforo sob pastejo = Chemical composition of Mombaça grass (Panicum maximum Jacq. cv. Mombaça fertilized with different phosphorus on grazing

    Directory of Open Access Journals (Sweden)

    Fábio Jacobs Dias

    2007-01-01

    Full Text Available O objetivo foi avaliar a composição química do Panicum maximum Jacq. cv. Mombaça, adubado com 140 kg ha-1 de P2O5 com diferentes fontes de fósforo, sob pastejo, no período de dezembro de 2002 a abril de 2003, com intervalo de coleta a cada 28 dias. Tratamentos: 1- termofosfato magnesiano YoorinÒ; 2-fosfato natural GafsaÒ; 3-superfosfato simples + superfosfato triplo (SS + ST; e 4-testemunha. Os teores de proteína bruta na lâmina foliar (PBf e colmo (PBc, nitrogênio insolúvel em detergente ácido (NIDA, fibra em detergente neutro (FDN, fibra em detergente ácido (FDA, celulose (CEL, hemicelulose (HCEL, lignina (LIG, extrato etéreo (EE, cálcio (Ca, fósforo (P, cinzas e carboidratos não-estruturais (CNE, não foram influenciados pela adubação fosfatada. As variáveis PBc, FDNf, FDNc, LIGf, LIGc, CELf, CELc, NIDAf, EEf, EEc, Caf, Cac, Pf, Pc, CINZAc, CNEc, apresentaram efeito do período de coleta. Não ocorreu diferença nacomposição química da forragem do capim-Mombaça em função das fontes de fósforo utilizadas na adubação da pastagem. As variações qualitativas foram de baixa magnitude.This study aimed to evaluate the chemical composition of Panicum maximum Jacq. cv. Mombaça. Grassland was fertilized with 140 kg ha-1 of P2O5 from different phosphorus sources on grazing, in December, 2002, until April, 2003, with a collection interval of every 28 days. Treatments: 1-YoorinÒ magnesium thermophosphate; 2-GafsaÒ natural phosphate; 3-simple superphosphate + triple superphosphate (SS + TS and 4-control. Leaf (lCP and stem (sCP crude protein, acid detergent fiber nitrogen (ADFN, neutral detergent fiber (NDF, acid detergent fiber (ADF, cellulose (CEL, hemicellulose (HEM, lignin (LIG, ether extract (EE, calcium (Ca, phosphorus (P, ash (A and non-structural carbohydrates (NSC were not influenced by phosphated fertilization. The variables sCP, lNDF, sNDF, sLIG, lLIG, sCEL, lCEL, lADFN, sEE, lEE, lCa, sCa, lP, sP, sA and s

  6. Efecto residual de dos rocas fosfóricas puras y parcialmente aciduladas, comparadas con SFT, sobre la aprovechabilidad del P por Panicum maximum L., en un oxisol de los Llanos Orientales de Colombia

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    Alejo M. Doris

    1986-03-01

    Full Text Available Panicum maximum L. se sembró, en condiciones de invernadero, en un Oxisol de los Llanos Orientales de Colombia, 18 meses después de la aplicación de las fuentes (rocas fosfóricas de Pesca - Colombia y Sechura - Perú crudas y aciduladas al 20 % con H3 P04, en dosis de 25, 50 Y 100 ppm de P. La roca fosfórica Sechura cruda y parcialmente acidulada junto con SFT, tuvieron el mejor efecto residual sobre el rendimiento y captación de P y mantuvieron los más altos niveles de P asimilable en el suelo al final del ensayo. Con las dosis superiores se obtuvo un nivel más alto de P asimilable en el suelo y mayor absorción de P por la planta.In order to study the residual effect of the Pesca (Colombia and Sechura (Perú phosphate rocks, both crude and acidulated in 20 % by H3P04, comparatively with SFT, Panicum rnaximum L. was planted under glasshouse conditions, in an Oxisol from the Eastern plains of Colombia, 18 months after sources application, with rates of 25. 50 and 100 ppm of P. Crude and partially acidulated Sechura phosphate rock, together with TSP, had the best residual effect on yield and P absorption and had the highest available P levels in the soil at the end of the trial. The highest available P level in the soil and P uptake by the plant was obtained with higher P rates.

  7. Saint Joseph's University Institute for Environmental Stewardship

    Energy Technology Data Exchange (ETDEWEB)

    McCann, Micahel P. [Saint Joseph' s Univ., Philadelphia, PA (United States); Springer, Clint J. [Saint Joseph' s Univ., Philadelphia, PA (United States)

    2014-06-03

    Task A: Examination of the physiological, morphological, and reproductive responses of Panicum virgatum (switchgrass) cultivars identified as potential biofuel producing cultivars as well as naturally-occurring varieties of switchgrass to projected changes in climate for the central portion of the United States. This project was a multi-year project set in a field site located at the Konza Prairie Biological Station near Manhattan, KS USA. The major objective of the study was to understand the physiological and growth responses of the important biofuel grass species, Panicum virgatum (switch grass) to simulated changes in precipitation expected for the Central Plains region of the United States. Population level adaptation to broad-scale regional climates or within-population variation in genome size of this genetically and phenotypically diverse C4 grass species may influence the responses to future precipitation variability associated with climate change. Therefore, we investigated switchgrass responses to water variability between natural populations collected across latitudinal gradient and populations. P. virgatum plants from natural populations originating from Kansas, Oklahoma, and Texas received frequent, small precipitation events (“ambient’) or infrequent, large precipitation events (‘altered”) to simulate contrasting rainfall variability expected from this region. We measured leaf-level physiology, aboveground biomass varied significantly by population origin but did not differ by genome size. Our results suggest that trait variation in P. virgatum is primarily attributed to population-level adaptation across latitudinal gradient, not genome size, and that neither population-level adaptation nor genome size may be important predictors of P. virgatum responses to future climatic conditions. Based solely on the data presented here, the most important consideration when deciding what varieties of switchgrass to cultivate for biofuel feedstocks under

  8. The enhancement by arbuscular mycorrhizal fungi of the Cd remediation ability and bioenergy quality-related factors of five switchgrass cultivars in Cd-contaminated soil

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    Hong Sun

    2018-03-01

    Full Text Available A greenhouse experiment was carried out to investigate the effects of arbuscular mycorrhizal fungi (AMF on the growth, P and Cd concentrations and bioenergy quality-related factors of five cultivars of switchgrass, including three lowland cultivars (Alamo (Ala, Kanlow (Kan, Performer (Per and two highland cultivars (Blackwell (Bw, Summer (Sum, with 0, 1 and 10 mg/kg Cd addition levels. The results showed that AMF inoculation notably increased the biomass and P concentrations of all the cultivars. The Cd concentrations in the roots were higher than those in the shoots of all cultivars irrespective of inoculation, but the AMF had different effects on Cd accumulation in highland and lowland cultivars. AMF inoculation decreased the shoot and root concentrations in Ala and Kan, increased the shoot and root concentrations of Cd in Bw and Sum, and increased shoot Cd concentrations and decreased root Cd concentrations in Per. The highest Cd concentrations were detected in the roots of Bw and in the shoots of Sum with AMF symbiosis. Bw contained the highest total extracted Cd which was primarily in the roots. Ala had the second highest extracted Cd in the shoots, reaching 32% with 1 mg/kg of added Cd, whereas Sum had the lowest extracted Cd. AMF symbiosis had varied effects on bioenergy quality-related factors: for example, AMF decreased the ash lignin content in Ala and the C/N in Sum, increased the nitrogen, gross calorie values, and maintained the hemicellulose and cellulose contents in all cultivars with all tested concentrations of Cd. A principal component analysis (PCA showed that AMF inoculation could enhance, weaken or transform (positive-negative, PC1-PC2 the correlations of these factors with the principle components under Cd stress. Therefore, AMF symbiosis enhanced the growth of different cultivars of switchgrass, increased/decreased Cd accumulation, promoted Cd extraction, and regulated the bioenergy quality-related factors in Cd

  9. pH foliar e deposição de gotas de pulverização em plantas daninhas aquáticas: Brachiaria mutica, Brachiaria subquadripara e Panicum repens Leaf pH and spray droplet deposition in aquatic weeds: Brachiaria mutica, Brachiaria subquadripara and Panicum repens

    Directory of Open Access Journals (Sweden)

    N.V. Costa

    2005-06-01

    Full Text Available A diversidade morfológica da superfície foliar existente entre as espécies de plantas e a presença de estruturas foliares, como tricomas, estômatos, cutícula e ceras, podem exercer grande influência na aderência e deposição das gotas de pulverização, assim como na absorção do herbicida. Dessa forma, o objetivo do presente trabalho foi estudar, em plantas daninhas aquáticas emersas (Brachiaria mutica, Brachiaria subquadripara e Panicum repens, o pH foliar, bem como a área de molhamento de gotas de pulverização na superfície foliar adaxial e abaxial. O experimento foi conduzido no Núcleo de Pesquisas Avançadas em Matologia - NUPAM, pertencente à Faculdade de Ciências Agronômicas de Botucatu/SP - UNESP. As plantas foram cultivadas em caixas d'água no campo, quando elas atingiram seu pleno desenvolvimento (antes do florescimento, foram feitas as avaliações de pH foliar e da área de molhamento de gotas de pulverização. As tensões superficiais das gotas depositadas (0,5 µL, apresentadas pelas soluções de glyphosate aplicado isoladamente (5,0% v v-1, Rodeo 480g L-1 e.a. - produto comercial, glyphosate + Aterbane BR (5,0% + 0,5% v v-1, glyphosate + Silwet L-77 (5,0% + 0,05% v v-1, além das soluções com os adjuvantes isolados, Aterbane BR (0,5% v v-1 e Silwet L-77 (0,05% v v-1, foram respectivamente de 72,1; 28,7; 23,3; 37,3; e 22,1 mN m-1. As médias obtidas de pH foliar variaram entre 5,71 e 6,03, destacando-se a espécie B. mutica, com valores de 5,72 e 6,03 para as faces adaxial e abaxial, respectivamente. Contudo, mais estudos devem ser realizados para verificar a influência do pH foliar na absorção de herbicidas por espécies daninhas aquáticas. Das plantas daninhas aquáticas avaliadas, B. subquadripara foi a espécie que obteve as maiores médias de área de molhamento nas faces adaxial e abaxial da folha, proporcionadas pelas soluções de glyphosate + Aterbane BR, glyphosate + Silwet L-77 e Silwet L-77

  10. NÍVEIS DE CALAGEM E FONTES DE FÓSFORO NA PRODUÇÃO DO CAPIM TANZÂNIA (Panicum maximum Jacq. cv. Tanzânia EFFECTS OF LIMING LEVELS AND PHOSPHORUS SOURCES ON TANZANIA GRASS YIELDS (Panicum maximum Jacq. cv. Tanzania

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    Luiz Augusto Fonseca Magalhães

    2007-09-01

    Full Text Available

    A deficiência de fósforo nos solos brasileiros, aliada à acidez natural dos solos de cerrado, contribuem para os baixos índices produtivos da pecuária nacional. O objetivo deste trabalho foi avaliar o efeito da calagem e de diferentes fontes e dosagens de fósforo na produção de matéria seca do capim Tanzânia (Panicum maximum Jacq. cv. Tanzânia. O experimento foi dividido em dois grupos, G1 e G2. No grupo G1 avaliaram-se três níveis de calagem (sem correção e com correções para elevar a saturação de bases para 30 e 60%, com doses de calcário de 1,12 e 2,64 t/ha, respectivamente e três fontes de fósforo (superfosfato simples, termofosfato Yoorin e hiperfosfato de Arad. No grupo G2 foram avaliados os mesmos três níveis de calagem e cinco doses de fósforo (0, 30, 60, 120 e 240 kg/ha de P. No G1 não houve interação entre as fontes de fósforo e a calagem, nem ocorreu efeito da calagem. Houve, contudo, diferenças significativas entre as fontes de fósforo, sendo o superfosfato simples superior ao termofosfato Yoorin e ao hiperfosfato de Arad. A produção de matéria seca no grupo G2 não foi influenciada pelos níveis de calagem. Contudo, houve diferença significativa entre os níveis de fósforo, com a máxima produção de matéria seca obtida com 172,8 kg/ha de P (395,6 kg/ha de P2O5. Não houve interação significativa entre calagem e dosagens de fósforo. Esse resultado reafirma a importância da adubação fosfatada para a produção, nos solos dos cerrados.

    PALAVRAS-CHAVE: Fósforo; calagem; forragem; tanzânia.

    The phosphorus deficiency and the natural acidity of Brazilian savannah soils contribute to the low productivity of Brazilian livestock raising. This research evaluated the effects of liming levels and phosphorus sources and levels in

  11. Métodos de colheita e qualidade das sementes de capim colonião cultivar Mombaça Effects of harvesting methods on seed quality of Panicum maximum (Jacq. cultivar Mombaça

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    Renata Waldemarin Maschietto

    2003-01-01

    Full Text Available A produção de sementes, em gramíneas forrageiras tropicais como o capim colonião (Panicum maximum Jacq., apresenta particularidades capazes de interferir na pureza física e na germinação das sementes. Por conseqüência, o método de colheita pode influenciar diretamente na qualidade das sementes produzidas. Buscando estudar o assunto, a presente pesquisa utilizou sementes de P. maximum cultivar Mombaça, colhidas pelos métodos (tratamentos do cacho, de varredura e mecanizado, as quais, previamente analisadas quanto à pureza física, foram armazenadas sob condições não controladas de laboratório durante 15 meses. A avaliação da qualidade fisiológica das sementes, realizada trimestralmente em seis épocas, constou da realização dos testes de germinação, de primeira contagem de germinação, de envelhecimento acelerado e de condutividade elétrica. Os resultados indicaram que há influência do método de colheita na qualidade das sementes; o método de varredura permite a obtenção de sementes que, embora de menor pureza física, apresentam maior qualidade fisiológica do que as provenientes dos métodos do cacho e mecânico.The production of higher quality seeds of tropical forage grasses such as guinea grass (Panicum maximum Jacq. presents some details that are able to influence on seed purity and germination. As a consequence, harvest time and method have a direct influence on seed quality. This research was carried out with the main objective of evaluating the quality of guinea grass seeds, cv Mombaça, harvested by three methods: a hand cutting the panicles followed by curing on the ground for three to five days; b hand collecting the shattered seeds from the ground and c mechanical. Seeds obtained from each harvesting procedure, were first evaluated for physical purity and then stored under uncontrolled conditions during 15 months. Germination, vigor (first count, accelerated aging, electrical conductivity were

  12. A Multipurpose Toolkit to Enable Advanced Genome Engineering in Plants

    Czech Academy of Sciences Publication Activity Database

    Čermák, Tomáš; Curtin, S.J.; Gil-Humanes, J.; Čegan, Radim; Kono, T.J.Y.; Konecna, E.; Belanto, J.J.; Starker, C.G.; Mathre, J.W.; Greenstein, R.L.; Voytas, D.F.

    2017-01-01

    Roč. 29, č. 6 (2017), s. 1196-1217 ISSN 1040-4651 Institutional support: RVO:68081707 Keywords : crispr /cas9-mediated targeted mutagenesis * zinc-finger nucleases * panicum-virgatum l. Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 8.688, year: 2016

  13. Water Use Efficiency for Establishing Biofuel Crops in Central Illinois

    Science.gov (United States)

    Bernacchi, C. J.; Zeri, M.; Hussain, M. Z.; Anderson-Teixeira, K. J.; Masters, M.; DeLucia, E. H.

    2012-12-01

    The production of biofuels from cellulosic plant material is expected to increase worldwide as countries look for alternative sources of energy. The choice of feedstocks suitable for ethanol production from cellulosic material must take into account several factors, such as productivity, response to local climate, and environmental impacts on the carbon, nitrogen and water cycles. With regards to the carbon cycle, the best options for biofuel crops are species that are highly productive in terms of harvestable biomass, but without depleting the soil carbon pools by requiring annual tillage before planting, as is the case of corn (Zea mays), the current dominant biofuel in the US. Perennial species such as miscanthus (Miscanthus × giganteus) and switchgrass (Panicum virgatum L.) have many advantages over annual crops due to the reduced use of fertilizer and less irrigation requirements relative to maize. The efficiency of plants in using water while accumulating biomass is an important factor when choosing the best biofuel crop to be planted in a certain location. Water use efficiency (WUE) is the term generally used to refer to the ratio of carbon accumulated over water used during a certain period of time. Water use efficiency is an important metric when cellulosic biofuels are considered, since it takes into account the benefits (carbon accumulated in soils or harvested) and the environmental impact (the use of water). This quantity is derived in many ways based on the metric of carbon for an ecosystem. Net ecosystem production (NEP) is the net balance of carbon derived from GPP - Re, where GPP is the gross primary production and Re is the ecosystem respiration. The ratio of NEP over total water used during the year (TWU) will be referred as EWUE, from "ecosystem" WUE. The value of EWUE represents ecological benefit of the feedstock, since it accounts for the carbon that might be accumulated in soils. Another metric is the HWUE, after "harvest" WUE, which

  14. Developing an Experimental Watershed for Monitoring the Impacts of Bioenergy Production on Marginal Lands of the Northeastern U.S

    Science.gov (United States)

    Rau, B. M.; Adler, P. R.; Kemanian, A. R.; Saha, D.; Montes, F.

    2012-12-01

    In the northeastern U.S. over 400,000 acres have been placed into conservation programs to reduce erosion and improve water quality. Most of this acreage is within the Chesepeake Bay watershed. Many of these acres may be suitable for raising second generation bioenergy crops such as switchgrass (Panicum virgatum L.) or miscanthus (Miscanthus × giganteus). Bioenergy production may provide a viable economic incentive to keep marginal lands in perennial crop production, and improve water quality. However, the environmental impacts and benefits of second generation bioenergy crop production are not well understood on marginal lands. We designed an experimental watershed to compare switchgrass and miscanthus production against typical conservation grasslands. The Mattern Watershed is a horseshoe shaped 1st order watershed located near Leck Kill, PA, and is representative of the Appalachian Ridge and Valley Province. The upper portions of the watershed have been and are currently used for tillage corn and bean production. The lower portions of the watershed are excessively wet and have been in a conservation easement since 2005. In spring 2012 we planted eight 0.4 ha replicate plots of switchgrass (4 fertilized and 4 with no fertilizer) and four 0.4 ha plots of miscanthus into the lower portions of the watershed an additional four 0.4 ha plots were left in conservation grassland using a randomized block design. We compare biomass production, biomass elemental content, N2O emissions, soil moisture, shallow groundwater quality, surface runoff, and soil organic carbon in order to determine which treatment most effectively produces bioenergy feedstock, mitigates greenhouse gas emissions, and improves water quality. The experimental watershed will provide an unparalleled opportunity to verify and parameterize watershed, and bigeochemical models. Preliminary results suggest that early in the growing season cool season grasses minimized shallow groundwater NO3 and N2O

  15. Características morfogênicas do capim-mombaça (Panicum maximum Jacq. cv. Mombaça adubado com fontes de fósforo, sob pastejo Morphogenic characteristics of mombaçagrass (Panicum maximum Jacq.cv. Mombaça fertilized with phosphorus sources, under grazing

    Directory of Open Access Journals (Sweden)

    Ulysses Cecato

    2007-12-01

    grazing return rate (GRR on mombaçagrass (Panicum maximum Jacq. cv. Mombaça. The experimental design was randomized blocks with three replications. There was no difference between phosphorus sources in all evaluated variables, except for leaf elongation rate, which was higher in tillers fertilized with the SPS+TSP treatment. Differences were found between evaluation periods, with summer showing higher leaf elongation rate and ligule height (first and last. The days evaluated indicated effect on first ligule height (FLH; LLH, number of expanded leaves (NEL, number of leaves in expansion (NFE, total number of leaves (TNL, total number of live leaves (TNLL, total number of senescent leaves (TLS, and grazing return rate (GRR. For days and period interactions only TNLL and TSL had positive linear correlations.

  16. Among and within family selection and combined half-sib family selection in Panicum maximum Jacq. Seleção entre e dentro de famílias e seleção combinada em famílias de meio-irmãos de Panicum maximum Jacq.

    Directory of Open Access Journals (Sweden)

    Janaina Azevedo Martuscello

    2009-10-01

    Full Text Available The objective of this study was to select superior genotypes in half-sib populations obtained from crosses between sexual plants and apomictic accessions. The experiment also proposed to compare among and within family and combined selection strategies. Ten plots of sexual plants were randomly distributed among 230 plots of apomictic accessions. After natural pollination, seeds of each sexual plant constituted a half-sib family. Thirty plants of each female progenitor were evaluated in a randomized block design experiment, with five plants per plot and five replications. Five evaluation harvests were made in the rainy seasons and two in the dry seasons of all plants. The production and quality characteristics were evaluated. The selection criteria used was: among and within family selection and combined selection with 50% selection in both. The selection criteria used (among and within family selection and combined selection, were efficient for use in P. maximum breeding, with medium to high gains for most characteristics evaluated. The highest genetic gains were obtained from combined selection. However, among and within family selection promoted high genetic gains and may be used in P. maximum breeding. The sexual progenitors identified as numbers 7, 1, 3 and 5 were promising and may be used in future crosses, as well as to increase the genetic variability in the P.maximum genebank.O experimento foi conduzido objetivando-se selecionar genótipos e genitores superiores de Panicum maximum em populações de meio-irmãos, originárias do cruzamento de plantas sexuais com plantas apomíticas, bem como comparar estratégias de seleção entre e dentro de famílias e seleção combinada. Dez parcelas de plantas sexuais de P. maximum foram aleatoriamente distribuídas entre 230 parcelas de acessos apomíticos. Após a fecundação natural, sementes de cada planta sexual constituíram-se uma família de meio-irmãos. Trinta plantas de cada genitora

  17. Engineered biochar from microwave-assisted catalytic pyrolysis of switchgrass for increasing water-holding capacity and fertility of sandy soil

    International Nuclear Information System (INIS)

    Mohamed, Badr A.; Ellis, Naoko; Kim, Chang Soo; Bi, Xiaotao; Emam, Ahmed El-raie

    2016-01-01

    Engineered biochars produced from microwave-assisted catalytic pyrolysis of switchgrass have been evaluated in terms of their ability on improving water holding capacity (WHC), cation exchange capacity (CEC) and fertility of loamy sand soil. The addition of K 3 PO 4 , clinoptilolite and/or bentonite as catalysts during the pyrolysis process increased biochar surface area and plant nutrient contents. Adding biochar produced with 10 wt.% K 3 PO 4 + 10 wt.% clinoptilolite as catalysts to the soil at 2 wt% load increased soil WHC by 98% and 57% compared to the treatments without biochar (control) and with 10 wt.% clinoptilolite, respectively. Synergistic effects on increased soil WHC were manifested for biochars produced from combinations of two additives compared to single additive, which may be the result of increased biochar microporosity due to increased microwave heating rate. Biochar produced from microwave catalytic pyrolysis was more efficient in increasing the soil WHC due to its high porosity in comparison with the biochar produced from conventional pyrolysis at the same conditions. The increases in soil CEC varied widely compared to the control soil, ranging from 17 to 220% for the treatments with biochars produced with 10 wt% clinoptilolite at 400 °C, and 30 wt% K 3 PO 4 at 300 °C, respectively. Strong positive correlations also exist among soil WHC with CEC and biochar micropore area. Biochar from microwave-assisted catalytic pyrolysis appears to be a novel approach for producing biochar with high sorption affinity and high CEC. These catalysts remaining in the biochar product would provide essential nutrients for the growth of bioenergy and food crops. - Highlights: • High quality biochar was made by catalytic pyrolysis in a microwave reactor. • High heating rate and good biochar quality were achieved using K 3 PO 4 and clinoptilolite mixture. • Biochars showed significant increase in soil WHC and CEC. • Microwave catalytic pyrolysis can produce

  18. Engineered biochar from microwave-assisted catalytic pyrolysis of switchgrass for increasing water-holding capacity and fertility of sandy soil.

    Science.gov (United States)

    Mohamed, Badr A; Ellis, Naoko; Kim, Chang Soo; Bi, Xiaotao; Emam, Ahmed El-Raie

    2016-10-01

    Engineered biochars produced from microwave-assisted catalytic pyrolysis of switchgrass have been evaluated in terms of their ability on improving water holding capacity (WHC), cation exchange capacity (CEC) and fertility of loamy sand soil. The addition of K3PO4, clinoptilolite and/or bentonite as catalysts during the pyrolysis process increased biochar surface area and plant nutrient contents. Adding biochar produced with 10wt.% K3PO4+10 wt.% clinoptilolite as catalysts to the soil at 2wt% load increased soil WHC by 98% and 57% compared to the treatments without biochar (control) and with 10wt.% clinoptilolite, respectively. Synergistic effects on increased soil WHC were manifested for biochars produced from combinations of two additives compared to single additive, which may be the result of increased biochar microporosity due to increased microwave heating rate. Biochar produced from microwave catalytic pyrolysis was more efficient in increasing the soil WHC due to its high porosity in comparison with the biochar produced from conventional pyrolysis at the same conditions. The increases in soil CEC varied widely compared to the control soil, ranging from 17 to 220% for the treatments with biochars produced with 10wt% clinoptilolite at 400°C, and 30wt% K3PO4 at 300°C, respectively. Strong positive correlations also exist among soil WHC with CEC and biochar micropore area. Biochar from microwave-assisted catalytic pyrolysis appears to be a novel approach for producing biochar with high sorption affinity and high CEC. These catalysts remaining in the biochar product would provide essential nutrients for the growth of bioenergy and food crops. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. INTERAÇÃO DO CALCÁRIO E DO SILICATO DE CÁLCIO E MAGNÉSIO COM GESSO AGRÍCOLA NO DESENVOLVIMENTO RADICULAR DE Panicum maximum JACQ. CV. CAPIM MOMBAÇA

    Directory of Open Access Journals (Sweden)

    Vinícius Faúla Aguiar

    2017-01-01

    Full Text Available O objetivo do trabalho é avaliar o efeito das correções do solo efetuadas com calcário e silicato de cálcio e magnésio no desenvolvimento radicular de Panicum maximum Jacq. Cultivar capim Mombaça. Foi adotado delineamento experimental em blocos ao acaso, em esquema fatorial 2x5, sendo estudado em quatro blocos o efeito de duas fontes de corretivo e cinco métodos de aplicação, além da testemunha. Nas análises onde foi observada significância estatística, realizou-se teste de Tukey a 5,0% de probabilidade. A unidade experimental é constituída por colunas de tubos de PVC de 15 centímetros de diâmetro por 60 cm de altura, dividida em seis anéis de 10 centímetros, totalizando 44 unidades. Depois de secas em estufa com circulação forçada de ar a 65 ºC até atingir peso constante as raízes foram pesadas em balança de precisão. O T2 resultou em maior incremento de massa seca. O crescimento radicular na faixa de 0 a 20 cm se mostrou superior às faixas de 20 a 40 e 40 a 60 cm.

  20. TERMINAÇÃO DE BOVINOS BRANGUS INTEIROS E CASTRADOS COM CANA-DEAÇÚCAR (SACCHARUM OFFICINARUM OU SILAGEM DE CAPIM MOMBAÇA (PANICUM MAXIMUM CV MOMBAÇA

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    Marcelo Diniz dos Santos

    2014-06-01

    Full Text Available The aim of this study was to evaluate the intake, weight gain, feed:gain ratio, carcass quality and economic viability of using fresh sugar cane and mombaça grass silage in Brangus castrated and intact males on termination. We used 140 Brangus cattle, with an average of 21 months and 355 kg live weight, identified and randomly assigned to treatments: T1, 37 intac males and T2, 37 castrated animals receiving both fresh sugar cane (Saccharum officinarum crushed;T3, 33 intact males and T4, 33 castrated animals, both fed mombaça grass silage (Panicum maximum cv mombaça. For economic evaluation, it was estimated the production costs of bulky coming from the farm costs, expenses concentrates, diesel, hand labor, equipment maintenance and control of 46 Colloquium Agrariae, v. 10, n.1, Jan-Jun. 2014, p.45-54. DOI: 10.5747/ca.2014.v10.n1.a099 parasites were also considered. The final weight of the entire animal was higher (P <0.05 than castrated animals. And feed conversion was higher in castrated animals, indicating that the bulls were more efficient in converting food into weight gain. The higher net revenue observed in intact males (mombaça is justified by the greater weight gain and lower diet costs. Animals that received diet with mombaça grass silage had greater economic feasibility of that received diet with sugar cane.

  1. Effect of germination on the phytase activity, phytate and total phosphorus contents of rice (Oryza sativa), maize (Zea mays), millet (Panicum miliaceum), sorghum (Sorghum bicolor) and wheat (Triticum aestivum).

    Science.gov (United States)

    Azeke, Marshall Arebojie; Egielewa, Samuel Jacob; Eigbogbo, Mary Ugunushe; Ihimire, Inegbenose Godwin

    2011-12-01

    The effect of germination on the level of phytase activity and the contents of phytates and phosphorus of five Nigeria grown cereal grains was studied. The cereals screened were rice (Oryza sativa), maize (Zea mays), millet (Panicum miliaceum), sorghum (Sorghum bicolor) and wheat (Triticum aestivum). Phytase activity was high (0.21-0.67 U g(-1)) in all samples. Phytate content ranged between 5.6 and 6.2 mg g(-1) while total phosphorus content ranged between 3.3 and 4.3 mg g(-1). During germination, the level of phytase activity increased and reached its maximal value after seven (16-fold), six (5-fold), five (7-fold), seven (3-fold) and eight (6-fold) days of germination for rice, maize, millet, sorghum and wheat respectively. After this initial increase, phytase activity declined slightly (P germination was accompanied by a significant reduction in phytate (P < 0.05) and a small but significant increase in total phosphorus.

  2. Engineered biochar from microwave-assisted catalytic pyrolysis of switchgrass for increasing water-holding capacity and fertility of sandy soil

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Badr A. [Department of Chemical and Biological Engineering, University of British Columbia, Vancouver BC V6T 1Z3 (Canada); Agricultural Engineering Department, Cairo University, Giza (Egypt); Ellis, Naoko [Department of Chemical and Biological Engineering, University of British Columbia, Vancouver BC V6T 1Z3 (Canada); Kim, Chang Soo [Department of Chemical and Biological Engineering, University of British Columbia, Vancouver BC V6T 1Z3 (Canada); Clean Energy Research Center, Korea Institute of Science and Technology, 14 gil 5 Hwarang-no Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Bi, Xiaotao, E-mail: tony.bi@ubc.ca [Department of Chemical and Biological Engineering, University of British Columbia, Vancouver BC V6T 1Z3 (Canada); Emam, Ahmed El-raie [Agricultural Engineering Department, Cairo University, Giza (Egypt)

    2016-10-01

    Engineered biochars produced from microwave-assisted catalytic pyrolysis of switchgrass have been evaluated in terms of their ability on improving water holding capacity (WHC), cation exchange capacity (CEC) and fertility of loamy sand soil. The addition of K{sub 3}PO{sub 4}, clinoptilolite and/or bentonite as catalysts during the pyrolysis process increased biochar surface area and plant nutrient contents. Adding biochar produced with 10 wt.% K{sub 3}PO{sub 4} + 10 wt.% clinoptilolite as catalysts to the soil at 2 wt% load increased soil WHC by 98% and 57% compared to the treatments without biochar (control) and with 10 wt.% clinoptilolite, respectively. Synergistic effects on increased soil WHC were manifested for biochars produced from combinations of two additives compared to single additive, which may be the result of increased biochar microporosity due to increased microwave heating rate. Biochar produced from microwave catalytic pyrolysis was more efficient in increasing the soil WHC due to its high porosity in comparison with the biochar produced from conventional pyrolysis at the same conditions. The increases in soil CEC varied widely compared to the control soil, ranging from 17 to 220% for the treatments with biochars produced with 10 wt% clinoptilolite at 400 °C, and 30 wt% K{sub 3}PO{sub 4} at 300 °C, respectively. Strong positive correlations also exist among soil WHC with CEC and biochar micropore area. Biochar from microwave-assisted catalytic pyrolysis appears to be a novel approach for producing biochar with high sorption affinity and high CEC. These catalysts remaining in the biochar product would provide essential nutrients for the growth of bioenergy and food crops. - Highlights: • High quality biochar was made by catalytic pyrolysis in a microwave reactor. • High heating rate and good biochar quality were achieved using K{sub 3}PO{sub 4} and clinoptilolite mixture. • Biochars showed significant increase in soil WHC and CEC.

  3. Ação do flúor dissolvido em chuva simulada sobre a estrutura foliar de Panicum maximum jacq. (colonião e Chloris gayana kunth. (capim-rhodes - Poaceae

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    Chaves Alba Lucilvânia Fonseca

    2002-01-01

    Full Text Available Panicum maximum e Chloris gayana foram submetidas à chuvas simuladas com soluções de fluoreto de potássio (15mg ml-1 com objetivo de identificar as injúrias causadas pelo flúor (F-, como poluente atmosférico, na estrutura da lâmina foliar e fornecer subsídios para a seleção de características diagnósticas a serem utilizadas na bioindicação. Os principais sintomas foram clorose e necrose, principalmente no ápice e margens das lâminas. Nos cortes transversais, quatro tipos de alterações causadas pelo flúor são relacionadas: redução do número, tamanho e arranjo dos cloroplastos; necrose dos tecidos principalmente nas margens das folhas; erosões na superfície da folha e hipertrofia das células. Em C. gayana, no entanto, não foram observadas as alterações nos cloroplastos e os outros sintomas foram bem mais discretos que em P. maximum. A ocorrência de compostos fenólicos foi registrada pela coloração com fucsina em todas as regiões da lâmina onde foram observadas lesões. Ao microscópio eletrônico de varredura foi observado o achatamento e formação de concavidades nas paredes externas das células. Este experimento confirma a maior sensibilidade de P. maximum ao flúor e revela algumas características anatômicas de C. gayana que, entre outros fatores, podem estar contribuindo para a maior resistência desta espécie a este poluente.

  4. Bioenergy Crop Breeding and Production Research in the Southeast, Final Report for 1996 to 2001

    Energy Technology Data Exchange (ETDEWEB)

    Bouton, J.H.

    2003-05-30

    Switchgrass (Panicum virgatum L.) is a native grass species to much of the US. It has shown great potential for use in production of fuel ethanol from cellulosic biomass (Lynd et al., 1991). Work in Alabama demonstrated very high dry matter yields can be achieved with switchgrass (Maposse et al. 1995) in the southeastern US. Therefore, this region is thought to be an excellent choice for development of a switchgrass cropping system where farmers can produce the grass for either biomass or forage. Another report has shown success with selection and breeding to develop high yielding germplasm from adapted cultivars and ecotypes of switchgrass (Moser and Vogel 1995). In the mid 1990s, however, there was little plant breeding effort for switchgrass with a potential for developing a cultivar for the southeast region. The main goal of the project was to develop adaptive, high-yielding switchgrass cultivars for use in cropping systems for bioenergy production in the southeastern US. A secondary objective was to assess the potential of alternate herbaceous species such as bermudagrass (Cynodon dactylon L.), bahiagrass (Paspalum notatum Flugge.), and napiergrass (Pennisetum purpureum Schumach.) that may compete with switchgrass for herbaceous bioenergy production in the southeast. During the conduct of the project, another goal of developing molecular markers useful for genetic mapping was added. The ''lowland'' cultivars, Alamo and Kanlow, were found to be the highest yielding switchgrass cultivars. Although most summers during the project period were hot and dry, their annual dry matter yield continue to outperform the best ''upland'' cultivars such as Cave-in-Rock, Shawnee, NE Late, and Trailblazer. The use of a breeding procedure based on the ''honeycomb design'' and multi-location progeny testing, coupled with the solid heritability and genetic gain estimates for dry matter yield in lowland type switchgrass

  5. Composição química do capim-Mombaça (Panicum maximum Jacq. cv. Mombaça adubado com diferentes fontes de fósforo sob pastejo - DOI: 10.4025/actascianimsci.v29i1.242 Chemical composition of Mombaça grass (Panicum maximum Jacq. cv. Mombaça fertilized with different phosphorus on grazing - DOI: 10.4025/actascianimsci.v29i1.242

    Directory of Open Access Journals (Sweden)

    Ulysses Cecato

    2007-11-01

    Full Text Available O objetivo foi avaliar a composição química do Panicum maximum Jacq. cv. Mombaça, adubado com 140 kg ha-1 de P2O5 com diferentes fontes de fósforo, sob pastejo, no período de dezembro de 2002 a abril de 2003, com intervalo de coleta a cada 28 dias. Tratamentos: 1- termofosfato magnesiano Yoorin®; 2-fosfato natural Gafsa®; 3-superfosfato simples + superfosfato triplo (SS + ST; e 4-testemunha. Os teores de proteína bruta na lâmina foliar (PBf e colmo (PBc, nitrogênio insolúvel em detergente ácido (NIDA, fibra em detergente neutro (FDN, fibra em detergente ácido (FDA, celulose (CEL, hemicelulose (HCEL, lignina (LIG, extrato etéreo (EE, cálcio (Ca, fósforo (P, cinzas e carboidratos não-estruturais (CNE, não foram influenciados pela adubação fosfatada. As variáveis PBc, FDNf, FDNc, LIGf, LIGc, CELf, CELc, NIDAf, EEf, EEc, Caf, Cac, Pf, Pc, CINZAc, CNEc, apresentaram efeito do período de coleta. Não ocorreu diferença na composição química da forragem do capim-Mombaça em função das fontes de fósforo utilizadas na adubação da pastagem. As variações qualitativas foram de baixa magnitude.This study aimed to evaluate the chemical composition of Panicum maximum Jacq. cv. Mombaça. Grassland was fertilized with 140 kg ha-1 of P2O5 from different phosphorus sources on grazing, in December, 2002, until April, 2003, with a collection interval of every 28 days. Treatments: 1-Yoorin® magnesium thermophosphate; 2-Gafsa® natural phosphate; 3-simple superphosphate + triple superphosphate (SS + TS and 4-control. Leaf (lCP and stem (sCP crude protein, acid detergent fiber nitrogen (ADFN, neutral detergent fiber (NDF, acid detergent fiber (ADF, cellulose (CEL, hemicellulose (HEM, lignin (LIG, ether extract (EE, calcium (Ca, phosphorus (P, ash (A and non-structural carbohydrates (NSC were not influenced by phosphated fertilization. The variables sCP, lNDF, sNDF, sLIG, lLIG, sCEL, lCEL, lADFN, sEE, lEE, lCa, sCa, lP, sP, sA and s

  6. Multifunctional landscapes: Site characterization and field-scale design to incorporate biomass production into an agricultural system

    Energy Technology Data Exchange (ETDEWEB)

    Ssegane, Herbert; Negri, M. Cristina; Quinn, John; Urgun-Demirtas, Meltem

    2015-09-01

    Current and future demand for food, feed, fiber, and energy require novel approaches to land management, which demands that multifunctional landscapes are created to integrate various ecosystem functions into a sustainable land use. We developed an approach to design such landscapes at a field scale to minimize concerns of land use change, water quality, and greenhouse gas emissions associated with production of food and bioenergy. This study leverages concepts of nutrient recovery and phytoremediation to place bioenergy crops on the landscape to recover nutrients released to watersheds by commodity crops. Crop placement is determined by evaluating spatial variability of: 1) soils, 2) surface flow pathways, 3) shallow groundwater flow gradients, 4) subsurface nitrate concentrations, and 5) primary crop yield. A 0.8 ha bioenergy buffer was designed within a 6.5 ha field to intercept concentrated surface flow, capture and use nitrate leachate, and minimize use of productive areas. Denitrification-Decomposition (DNDC) simulations show that on average, a switchgrass (Panicum Virgatum L.) or willow (Salix spp.) buffer within this catchment according to this design could reduce annual leached NO3 by 61 or 59% and N2O emission by 5.5 or 10.8%, respectively, produce 8.7 or 9.7 Mg ha-1 of biomass respectively, and displace 6.7 Mg ha-1 of corn (Zea mays L.) grain. Therefore, placement of bioenergy crops has the potential to increase environmental sustainability when the pairing of location and crop type result in minimal disruption of current food production systems and provides additional environmental benefits.

  7. Modeling state-level soil carbon emission factors under various scenarios for direct land use change associated with United States biofuel feedstock production

    International Nuclear Information System (INIS)

    Kwon, Ho-Young; Mueller, Steffen; Dunn, Jennifer B.; Wander, Michelle M.

    2013-01-01

    Current estimates of life cycle greenhouse gas emissions of biofuels produced in the US can be improved by refining soil C emission factors (EF; C emissions per land area per year) for direct land use change associated with different biofuel feedstock scenarios. We developed a modeling framework to estimate these EFs at the state-level by utilizing remote sensing data, national statistics databases, and a surrogate model for CENTURY's soil organic C dynamics submodel (SCSOC). We estimated the forward change in soil C concentration within the 0–30 cm depth and computed the associated EFs for the 2011 to 2040 period for croplands, grasslands or pasture/hay, croplands/conservation reserve, and forests that were suited to produce any of four possible biofuel feedstock systems [corn (Zea Mays L)-corn, corn–corn with stover harvest, switchgrass (Panicum virgatum L), and miscanthus (Miscanthus × giganteus Greef et Deuter)]. Our results predict smaller losses or even modest gains in sequestration for corn based systems, particularly on existing croplands, than previous efforts and support assertions that production of perennial grasses will lead to negative emissions in most situations and that conversion of forest or established grasslands to biofuel production would likely produce net emissions. The proposed framework and use of the SCSOC provide transparency and relative simplicity that permit users to easily modify model inputs to inform biofuel feedstock production targets set forth by policy. -- Highlights: ► We model regionalized feedstock-specific United States soil C emission factors. ► We simulate soil C changes from direct land use change associated with biofuel feedstock production. ► Corn, corn-stover, and perennial grass biofuel feedstocks grown in croplands maintain soil C levels. ► Converting grasslands to bioenergy crops risks soil C loss. ► This modeling framework yields more refined soil C emissions than national-level emissions

  8. Mapping Intra-Field Yield Variation Using High Resolution Satellite Imagery to Integrate Bioenergy and Environmental Stewardship in an Agricultural Watershed

    Directory of Open Access Journals (Sweden)

    Yuki Hamada

    2015-07-01

    Full Text Available Biofuels are important alternatives for meeting our future energy needs. Successful bioenergy crop production requires maintaining environmental sustainability and minimum impacts on current net annual food, feed, and fiber production. The objectives of this study were to: (1 determine under-productive areas within an agricultural field in a watershed using a single date; high resolution remote sensing and (2 examine impacts of growing bioenergy crops in the under-productive areas using hydrologic modeling in order to facilitate sustainable landscape design. Normalized difference indices (NDIs were computed based on the ratio of all possible two-band combinations using the RapidEye and the National Agricultural Imagery Program images collected in summer 2011. A multiple regression analysis was performed using 10 NDIs and five RapidEye spectral bands. The regression analysis suggested that the red and near infrared bands and NDI using red-edge and near infrared that is known as the red-edge normalized difference vegetation index (RENDVI had the highest correlation (R2 = 0.524 with the reference yield. Although predictive yield map showed striking similarity to the reference yield map, the model had modest correlation; thus, further research is needed to improve predictive capability for absolute yields. Forecasted impact using the Soil and Water Assessment Tool model of growing switchgrass (Panicum virgatum on under-productive areas based on corn yield thresholds of 3.1, 4.7, and 6.3 Mg·ha−1 showed reduction of tile NO3-N and sediment exports by 15.9%–25.9% and 25%–39%, respectively. Corresponding reductions in water yields ranged from 0.9% to 2.5%. While further research is warranted, the study demonstrated the integration of remote sensing and hydrologic modeling to quantify the multifunctional value of projected future landscape patterns in a context of sustainable bioenergy crop production.

  9. Rare earth elements (REEs): effects on germination and growth of selected crop and native plant species.

    Science.gov (United States)

    Thomas, Philippe J; Carpenter, David; Boutin, Céline; Allison, Jane E

    2014-02-01

    The phytotoxicity of rare earth elements (REEs) is still poorly understood. The exposure-response relationships of three native Canadian plant species (common milkweed, Asclepias syriaca L., showy ticktrefoil, Desmodium canadense (L.) DC. and switchgrass, Panicum virgatum L.) and two commonly used crop species (radish, Raphanus sativus L., and tomato, Solanum lycopersicum L.) to the REEs lanthanum (La), yttrium (Y) and cerium (Ce) were tested. In separate experiments, seven to eight doses of each element were added to the soil prior to sowing seeds. Effects of REE dose on germination were established through measures of total percent germination and speed of germination; effects on growth were established through determination of above ground biomass. Ce was also tested at two pH levels and plant tissue analysis was conducted on pooled samples. Effects on germination were mostly observed with Ce at low pH. However, effects on growth were more pronounced, with detectable inhibition concentrations causing 10% and 25% reductions in biomass for the two native forb species (A. syriaca and D. canadense) with all REEs and on all species tested with Ce in both soil pH treatments. Concentration of Ce in aboveground biomass was lower than root Ce content, and followed the dose-response trend. From values measured in natural soils around the world, our results continue to support the notion that REEs are of limited toxicity and not considered extremely hazardous to the environment. However, in areas where REE contamination is likely, the slow accumulation of these elements in the environment could become problematic. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Analyzing the impacts of three types of biochar on soil carbon fractions and physiochemical properties in a corn-soybean rotation.

    Science.gov (United States)

    Sandhu, Saroop S; Ussiri, David A N; Kumar, Sandeep; Chintala, Rajesh; Papiernik, Sharon K; Malo, Douglas D; Schumacher, Thomas E

    2017-10-01

    Biochar is a solid material obtained when biomass is thermochemically converted in an oxygen-limited environment. In most previous studies, the impacts of biochar on soil properties and organic carbon (C) were investigated under controlled conditions, mainly laboratory incubation or greenhouse studies. This 2-year field study was conducted to evaluate the influence of biochar on selected soil physical and chemical properties and carbon and nitrogen fractions for two selected soil types (clay loam and a sandy loam soil) under a corn (Zea mays L.)-soybean (Glycine max L.) rotation. The three plant based biochar materials used for this study were corn stover (CS), ponderosa pine (Pinus ponderosa Lawson and C. Lawson) wood residue (PW), and switchgrass (Panicum virgatum L.) (SG). Data showed that CS and SG significantly increased the pH of acidic soil at the eroded landscape position but produced no significant change in soil pH at the depositional landscape position. The effects of biochar treatments on cold water extractable C (WSC) and nitrogen (WSN) fractions for the 0-7.5 cm depth were depended on biochar and soil type. Results suggested that alkaline biochars applied at 10 Mg ha -1 can increase the pH and WSC fraction of acidic sandy loam soil, but the 10 Mg ha -1 rate might be low to substantially improve physical properties and hot water extractable C and N fractions of soil. Application of higher rates of biochar and long-term monitoring is needed to quantify the benefits of biochar under field conditions on soils in different environmental conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Ubiquity of insect-derived nitrogen transfer to plants by endophytic insect-pathogenic fungi: an additional branch of the soil nitrogen cycle.

    Science.gov (United States)

    Behie, Scott W; Bidochka, Michael J

    2014-03-01

    The study of symbiotic nitrogen transfer in soil has largely focused on nitrogen-fixing bacteria. Vascular plants can lose a substantial amount of their nitrogen through insect herbivory. Previously, we showed that plants were able to reacquire nitrogen from insects through a partnership with the endophytic, insect-pathogenic fungus Metarhizium robertsii. That is, the endophytic capability and insect pathogenicity of M. robertsii are coupled so that the fungus acts as a conduit to provide insect-derived nitrogen to plant hosts. Here, we assess the ubiquity of this nitrogen transfer in five Metarhizium species representing those with broad (M. robertsii, M. brunneum, and M. guizhouense) and narrower insect host ranges (M. acridum and M. flavoviride), as well as the insect-pathogenic fungi Beauveria bassiana and Lecanicillium lecanii. Insects were injected with (15)N-labeled nitrogen, and we tracked the incorporation of (15)N into two dicots, haricot bean (Phaseolus vulgaris) and soybean (Glycine max), and two monocots, switchgrass (Panicum virgatum) and wheat (Triticum aestivum), in the presence of these fungi in soil microcosms. All Metarhizium species and B. bassiana but not L. lecanii showed the capacity to transfer nitrogen to plants, although to various degrees. Endophytic association by these fungi increased overall plant productivity. We also showed that in the field, where microbial competition is potentially high, M. robertsii was able to transfer insect-derived nitrogen to plants. Metarhizium spp. and B. bassiana have a worldwide distribution with high soil abundance and may play an important role in the ecological cycling of insect nitrogen back to plant communities.

  12. Leaching and ponding of viral contaminants following land application of biosolids on sandy-loam soil.

    Science.gov (United States)

    Wong, Kelvin; Harrigan, Tim; Xagoraraki, Irene

    2012-12-15

    Much of the land available for application of biosolids is cropland near urban areas. Biosolids are often applied on hay or grassland during the growing season or on corn ground before planting or after harvest in the fall. In this study, mesophilic anaerobic digested (MAD) biosolids were applied at 56,000 L/ha on a sandy-loam soil over large containment lysimeters seeded to perennial covers of orchardgrass (Dactylis glomerata L.), switchgrass (Panicum virgatum), or planted annually to maize (Zea mays L.). Portable rainfall simulators were to maintain the lysimeters under a nearly saturated (90%, volumetric basis) conditions. Lysimeter leachate and surface ponded water samples were collected and analyzed for somatic phage, adenoviruses, and anionic (chloride) and microbial (P-22 bacteriophage) tracers. Neither adenovirus nor somatic phage was recovered from the leachate samples. P-22 bacteriophage was found in the leachate of three lysimeters (removal rates ranged from 1.8 to 3.2 log(10)/m). Although the peak of the anionic tracer breakthrough occurred at a similar pore volume in each lysimeter (around 0.3 pore volume) the peak of P-22 breakthrough varied between lysimeters (worm holes or other natural phenomena. The concentration of viral contaminants collected in ponded surface water ranged from 1 to 10% of the initial concentration in the applied biosolids. The die off of somatic phage and P-22 in the surface water was fit to a first order decay model and somatic phage reached background level at about day ten. In conclusion, sandy-loam soils can effectively remove/adsorb the indigenous viruses leached from the land-applied biosolids, but there is a potential of viral pollution from runoff following significant rainfall events when biosolids remain on the soil surface. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. The second green revolution? Production of plant-based biodegradable plastics.

    Science.gov (United States)

    Mooney, Brian P

    2009-03-01

    Biodegradable plastics are those that can be completely degraded in landfills, composters or sewage treatment plants by the action of naturally occurring micro-organisms. Truly biodegradable plastics leave no toxic, visible or distinguishable residues following degradation. Their biodegradability contrasts sharply with most petroleum-based plastics, which are essentially indestructible in a biological context. Because of the ubiquitous use of petroleum-based plastics, their persistence in the environment and their fossil-fuel derivation, alternatives to these traditional plastics are being explored. Issues surrounding waste management of traditional and biodegradable polymers are discussed in the context of reducing environmental pressures and carbon footprints. The main thrust of the present review addresses the development of plant-based biodegradable polymers. Plants naturally produce numerous polymers, including rubber, starch, cellulose and storage proteins, all of which have been exploited for biodegradable plastic production. Bacterial bioreactors fed with renewable resources from plants--so-called 'white biotechnology'--have also been successful in producing biodegradable polymers. In addition to these methods of exploiting plant materials for biodegradable polymer production, the present review also addresses the advances in synthesizing novel polymers within transgenic plants, especially those in the polyhydroxyalkanoate class. Although there is a stigma associated with transgenic plants, especially food crops, plant-based biodegradable polymers, produced as value-added co-products, or, from marginal land (non-food), crops such as switchgrass (Panicum virgatum L.), have the potential to become viable alternatives to petroleum-based plastics and an environmentally benign and carbon-neutral source of polymers.

  14. Potential uses of biomass from fast-growing crop miscanthus×giganteus

    Directory of Open Access Journals (Sweden)

    Babović Nada V.

    2012-01-01

    Full Text Available There is an increasing interest in perennial grasses as a renewable source of bioenergy and feedstock for second-generation cellulosic biofuels. Switchgrass (Panicum virgatum and miscanthus (Miscanthus×giganteus, belonging to the parennial grasses group, are the major lignocellulosic materials being studied today as sources for direct energy production, biofuels, bioremediation and other. They have the ability to grow at low cost on marginal land where they will not compete with the traditional food crops. Miscanthus×giganteus possesses a number of advantages in comparison with the other potential energy crops such as are: high yields, low moisture content at harvest, high water and nitrogen use efficiencies, low need for annual agronomic inputs such as fertilizers and pesticides, high cellulose content, non-invasive character, low susceptibility to pests and diseases and broad adaptation to temperate growing environments. The main problems are low rate of survival during the first winter after the creation of plantation and the relatively high establishment costs. Miscanthus×giganteus is grown primarily for heat and electricity generation but can also be used to produce transport fuels. Miscanthus biomass has a very good combustion quality due to its low water concentration as well as its low Cl, K, N, S and ash concentrations compared to other lignocellulose plants. It is expected that miscanthus will provide cheaper and more sustainable source of cellulose for production of bioethanol than annual crops such as corn. Miscanthus has great promise as a renewable energy source, but it can only be realised when the grass production has been optimised for large-scale commercial cultivation. However, further research is still needed to optimise agronomy of miscanthus, to develop the production chain and pre-treatment as well as to optimise energy conversation route to produce heat, electricity, and/or fuels from biomass, if miscanthus is to

  15. (Pennisetum purpureum Schum) and switchgrass

    African Journals Online (AJOL)

    user

    acceptable to the paper industry. The low tear strength values might impact negatively on print room runnability of paper sheets from the two tested species. REFERENCES. Akhtaruzzaman AFM, Shafi M (1995). Pulping of jute. Tappi J., 78: 106-. 112. CPPA (1997). Canadian Pulp and Paper Association. Testing Methods.

  16. Spatial optimization of cropping pattern for sustainable food and biofuel production with minimal downstream pollution.

    Science.gov (United States)

    Femeena, P V; Sudheer, K P; Cibin, R; Chaubey, I

    2018-04-15

    Biofuel has emerged as a substantial source of energy in many countries. In order to avoid the 'food versus fuel competition', arising from grain-based ethanol production, the United States has passed regulations that require second generation or cellulosic biofeedstocks to be used for majority of the biofuel production by 2022. Agricultural residue, such as corn stover, is currently the largest source of cellulosic feedstock. However, increased harvesting of crops residue may lead to increased application of fertilizers in order to recover the soil nutrients lost from the residue removal. Alternatively, introduction of less-fertilizer intensive perennial grasses such as switchgrass (Panicum virgatum L.) and Miscanthus (Miscanthus x giganteus Greef et Deu.) can be a viable source for biofuel production. Even though these grasses are shown to reduce nutrient loads to a great extent, high production cost have constrained their wide adoptability to be used as a viable feedstock. Nonetheless, there is an opportunity to optimize feedstock production to meet bioenergy demand while improving water quality. This study presents a multi-objective simulation optimization framework using Soil and Water Assessment Tool (SWAT) and Multi Algorithm Genetically Adaptive Method (AMALGAM) to develop optimal cropping pattern with minimum nutrient delivery and minimum biomass production cost. Computational time required for optimization was significantly reduced by loose coupling SWAT with an external in-stream solute transport model. Optimization was constrained by food security and biofuel production targets that ensured not more than 10% reduction in grain yield and at least 100 million gallons of ethanol production. A case study was carried out in St. Joseph River Watershed that covers 280,000 ha area in the Midwest U.S. Results of the study indicated that introduction of corn stover removal and perennial grass production reduce nitrate and total phosphorus loads without

  17. Differential priming of soil carbon driven by soil depth and root impacts on carbon availability

    Energy Technology Data Exchange (ETDEWEB)

    de Graaff, Marie-Anne; Jastrow, Julie D.; Gillette, Shay; Johns, Aislinn; Wullschleger, Stan D.

    2013-11-15

    Enhanced root-exudate inputs can stimulate decomposition of soil carbon (C) by priming soil microbial activity, but the mechanisms controlling the magnitude and direction of the priming effect remain poorly understood. With this study we evaluated how differences in soil C availability affect the impact of simulated root exudate inputs on priming. We conducted a 60-day laboratory incubation with soils collected (60 cm depth) from under six switchgrass (Panicum virgatum) cultivars. Differences in specific root length (SRL) among cultivars were expected to result in small differences in soil C inputs and thereby create small differences in the availability of recent labile soil C; whereas soil depth was expected to create large overall differences in soil C availability. Soil cores from under each cultivar (roots removed) were divided into depth increments of 0–10, 20–30, and 40–60 cm and incubated with addition of either: (1) water or (2) 13C-labeled synthetic root exudates (0.7 mg C/g soil). We measured CO2 respiration throughout the experiment. The natural difference in 13C signature between C3 soils and C4 plants was used to quantify cultivar-induced differences in soil C availability. Amendment with 13C-labeled synthetic root-exudate enabled evaluation of SOC priming. Our experiment produced three main results: (1) switchgrass cultivars differentially influenced soil C availability across the soil profile; (2) small differences in soil C availability derived from recent root C inputs did not affect the impact of exudate-C additions on priming; but (3) priming was greater in soils from shallow depths (relatively high total soil C and high ratio of labile-to-stable C) compared to soils from deep depths (relatively low total soil C and low ratio of labile-to-stable C). These findings suggest that the magnitude of the priming effect is affected, in part, by the ratio of root exudate C inputs to total soil C and that the impact of changes in exudate inputs on

  18. Effect of sources of phosphorus on “in vitro” digestibility of dry matter, organic matter and total digestible nutrients of Mombaça grass (Panicum maximum Jacq. Cv. Mombaça/ Efeito de fontes de fósforo sobre a digestibilidade “in vitro” da matéria seca, da matéria orgânica e nutrientes digestíveis totais do capim- Mombaça (Panicum maximum Jacq. Cv. Mombaça

    Directory of Open Access Journals (Sweden)

    Carlos Antonio Lopes de Oliveira

    2008-08-01

    Full Text Available The trial was performed to evaluate the effect of phosphorus sources on forage mass quality of Mombaça grass (Panicum maximum Jacq. cv. Mombaça, according to in vitro dry matter and organic matter digestibility and TDN concentration. Every month, samples of available forage mass were taken, from December, 2002 until April, 2003. The treatments were three phosphate sources (1-YoorinÆÊ magnesium thermophosphate; 2-GafsaÆÊ natural phosphate; 3-simple superphosphate + triple superphosphate and the control (no fertilizer. They were arranged in a randomised block design with three replications. It was used 12 plots sized from 0,7 to 1,0 hectare, which were delimited by two-line eletric fence. The grazing method was continuous stocking and variable stocking rate (“put-and-take”. The IVDMD, IVOMD and TDN coefficients decreased along sampling period. IVDMD, IVOMD and TDN concentration didn’t show significantly differences among treatments (P>0.05.O trabalho foi realizado com o objetivo de avaliar o efeito de fontes de fósforo sobre a qualidade de massa de forragem do capim-Mombaça (Panicum maximum Jacq. cv. Mombaça, no que se refere à digestibilidade “in vitro” da matéria seca e da matéria orgânica e concentração de NDT. Foram feitas amostragens mensais da massa de forragem disponível, no período de dezembro de 2002 a abril de 2003. Os tratamentos avaliados foram três fontes de fósforo (1-termofosfato magnesiano YoorinÆÊ; 2-fosfato natural GafsaÆÊ; 3-superfosfato simples + superfosfato triplo e tratamento testemunha, distribuídos em delineamento de blocos casualisados com três repetições. Foram utilizados 12 piquetes com tamanho de 0,7 a 1,0 hectare, separados por cerca com dois fios eletrificados. O método de pastejo utilizado foi o da lotação contínua com carga variável (“put-and-take”. Os coeficientes de DIVMS, DIVMO e NDT reduziram ao longo do período de coleta. Entre os tratamentos, a DIVMS, DIVMO e

  19. Etude comparative de la digestibilité in vivo de l'herbe de guinée (Panicum maximum Jacq. associée aux feuilles et tiges de patate douce (Ipomoea batatas (L. Lam (régime Panipo ou à l'herbe de lait (Euphorbia heterophylla L. (régime Paneuph chez le lapin (Oryctolagus cuniculus L. et le cobaye (Cavia porcellus L.

    Directory of Open Access Journals (Sweden)

    Kouakou, NGDV.

    2016-01-01

    Full Text Available Digestibility of Guinea grass (Panicum maximum Jacq. associated with sweet potato leaves and stems (Ipomoea batatas (L. Lam (Panipo diet or poison milk (Euphorbia heterophylla L. (Paneuph diet in Rabbits (Oryctolagus cuniculus L. and in Guinea Pigs (Cavia porcellus L.. A comparative study of in vivo digestibility of Guinea grass (Panicum maximum Jacq. associated with sweet potato leaves and stems (Ipomoea batatas (L. Lam (Panipo diet or with poison milk (Euphorbia heterophylla L. (Paneuph diet was conducted involving 16 rabbits and 16 weaned guinea pigs fed ad libitum. Paneuph was significantly better ingested (P0.05 for guinea pigs. Poison milk was better ingested than the leaves and stems of sweet potato (P0.05. The ADC of DM, OM and MAT of Paneuph exceeded 80% and were higher than those of Panipo in rabbits and guinea pigs (P<0.05. Based on the results obtained, the effects of the distribution of the Guinea grass associated with the poison milk during rabbits growing have to be further studied before recommending this new diet to farmers in areas where poison milk and Guinea grass are present and rabbit breeding enough developed.

  20. Fatores limitantes ao crescimento do capim-Tanzânia em um sistema agrossilvipastoril com eucalipto, na região dos Cerrados de Minas Gerais Factors limiting the growth of Panicum maximum cv. Tanzânia-1 in an agrosilvopastoral system with eucalypt, in the Cerrados of Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Soares de Andrade

    2001-07-01

    Full Text Available Conduziu-se um estudo em um sistema agrossilvipastoril, constituído por Eucalyptus urophylla e Panicum maximum cv. Tanzânia-1, para verificar a hipótese de que existiam outros fatores, além da baixa disponibilidade de luz, interferindo no crescimento normal da gramínea, quatro anos após sua introdução no sistema. O estudo consistiu de um ensaio de adubação NPK a campo, adotando-se o delineamento experimental de blocos casualizados, com os tratamentos dispostos no arranjo fatorial 2³, com duas doses de nitrogênio (0 e 100 kg/ha de N, fósforo (0 e 70 kg/ha de P2O5 e potássio (0 e 100 kg/ha de K2O. A gramínea não respondeu ao P nem ao K, embora os teores originais de P e K disponíveis no solo fossem baixos. A adubação nitrogenada dobrou a taxa de acumulação de matéria seca do sub-bosque, mostrando que o crescimento da gramínea estava sendo restringido pela baixa disponibilidade de N no solo. A elevada resposta à adubação nitrogenada mostrou que o sombreamento não era o único fator limitando a produtividade do sub-bosque, e, também, que as plantas estabelecidas do capim-tanzânia não estavam sendo afetadas negativa e significativamente por substâncias alelopáticas produzidas pelo eucalipto.A study was conducted in an agrosilvopastoral system, constituted by Eucalyptus urophylla and Panicum maximum cv. Tanzânia-1, to verify the hypothesis that there were other factors, besides the low light availability, affecting the normal growth of the grass, four years after its introduction in the system. A NPK fertilization field trial was carry out, using the randomized block design, with the treatments in the 2³ factorial outline, with two doses of nitrogen (0 and 100 kg/ha of N, phosphorus (0 and 70 kg/ha of P2O5 and potassium (0 and 100 kg/ha of K2O. The grass did not respond to P nor K fertilization, in spite of the low original P and K availability in the soil. However, with the application of nitrogen the rate of herbage

  1. Fluxes of nitrous oxide and carbon dioxide over four potential biofuel crops in Central Illinois

    Science.gov (United States)

    Zeri, M.; Hickman, G. C.; Bernacchi, C.

    2009-12-01

    Nitrous oxide (N2O) and carbon dioxide (CO2) are important greenhouse gases that contribute to global climate change. Agriculture is a significant source of N2O to the atmosphere due to the use of nitrogen-based fertilizers. Fluxes of N2O and CO2 are measured using the flux-gradient technique over four different crops at the Energy Farm, a University of Illinois research facility in Urbana, Illinois. Measurements started in June of 2009 and are part of a project that aims to assess the impacts of potential biofuel crops on the carbon, water and nitrogen cycles. The species chosen are Maize (Zea mays), Miscanthus (Miscanthus x giganteus), Switchgrass (Panicum virgatum) and Prairie (a mix of several native species). The choice of species was based on their potential for the production of second-generation biofuels, i.e., fuels derived from the decomposition of the cellulosic material in the plant biomass. The use of corn residue for cellulosic biofuels might impact the carbon cycle through the reduction of soil organic content. Miscanthus is a perennial grass with great potential for biomass production. However, the total water used during the growing season and its water use efficiency might impose limits on the regions where this biofuel crop can be sustainably planted on a large scale. Switchgrass and the prairie species are less productive but might be suited for being well adapted and easy to establish. This study is the first side-by-side comparison of fluxes of N2O for these agro-ecosystems. The measurements are performed at micrometeorological towers placed at the center of 4 ha plots. The air is sampled at two heights over the vegetation and is analyzed in a tunable diode laser (TDL) installed nearby. A valve system cycles the TDL measurements trough all the intakes in the plots. The fluxes are calculated using the flux-gradient method, which requires the knowledge of the scalar vertical gradient as well as of the friction velocity (u*) and the Monin

  2. Differential effects of biochar on soils within an eroded field

    Science.gov (United States)

    Schumacher, Thomas; Chintala, Rajesh; Sandhu, Saroop; Kumar, Sandeep; Clay, Dave; Gelderman, Ron; Papiernik, Sharon; Malo, Douglas; Clay, Sharon; Julson, Jim

    2015-04-01

    Future uses of biochar will in part be dependent not only on the effects of biochar on soil processes but also on the availability and economics of biochar production. If pyrolysis for production of bio-oil and syngas becomes wide-spread, biochar as a by-product of bio-oil production will be widely available and relatively inexpensive compared to the production of biochar as primary product. Biochar produced as a by-product of optimized bio-oil production using regionally available feedstocks was examined for properties and for use as an amendment targeted to contrasting soils within an eroded field in an on-farm study initiated in 2013 at Brookings, South Dakota, USA. Three plant based biochar materials produced from carbon optimized gasification of corn stover (Zea mays L.), Ponderosa pine (Pinus ponderosa Lawson and C. Lawson) wood residue, and switchgrass (Panicum virgatum L.) were applied at a 1% (w/w) rate to a Maddock soil (Sandy, Mixed, Frigid Entic Hapludolls) located in an eroded upper landscape position and a Brookings soil (Fine-Silty, Mixed, Superactive, Frigid Pachic Hapludolls) located in a depositional landscape position. The cropping system within this agricultural landscape was a corn (Zea mays L.) and soybean (Glycine max L.) rotation. Biochar physical and chemical properties for each of the feedstocks were determined including pH, surface area, surface charge potential, C-distribution, ash content, macro and micro nutrient composition. Yields, nutrient content, and carbon isotope ratio measurements were made on the harvested seed. Soil physical properties measured included water retention, bulk density, and water infiltration from a ponded double ring infiltrometer. Laboratory studies were conducted to determine the effects of biochar on partitioning of nitrate and phosphorus at soil surface exchange complex and the extracellular enzymes activity of C and N cycles. Crop yields were increased only in the Maddock soil. Biochar interacted with each

  3. Neutron imaging of root water uptake, transport and hydraulic redistribution

    Science.gov (United States)

    Warren, J.; Bilheux, H.; Kang, M.; Voisin, S.; Cheng, C.; Horita, J.; Perfect, E.

    2012-12-01

    Knowledge of plant water fluxes is critical for assessing mechanistic processes linked to biogeochemical cycles, yet resolving root water transport dynamics has been a particularly daunting task. Our objectives were to demonstrate the ability to non-invasively monitor individual root functionality and water fluxes within 1-3-week old Zea mays L. (maize) and Panicum virgatum L. (switchgrass) seedlings using neutron imaging. Seedlings were propagated in a growth chamber adjacent to the HFIR CG1 Beam Line at Oak Ridge National Laboratory in cylindrical or plate-like aluminum chambers containing sand. Seedlings were maintained under fairly dry conditions, with water added only to replace daily evapotranspiration. Plants were placed into the high flux cold neutron beam line and injections of H2O or deuterium oxide (D2O) were tracked through the soil and root systems by collecting consecutive CCD radiographs through time. Water fluxes within the root systems were manipulated by cycling on a growth lamp that altered foliar demand for water and thus internal water potential driving forces. 2D and 3D neutron radiography readily illuminated root structure, root growth, and relative plant and soil water content. 2D pulse-chase irrigation experiments with H2O and D2O, which have different neutron cross sections and thus differences in resulting image contrast, successfully allowed observation of uptake and mass flow of water within the root system. After irrigation there was rapid root water uptake from the newly wetted soil, followed by progressive hydraulic redistribution of water through the root systems to roots terminating in dry soil. Water flux within individual roots responded differentially to foliar illumination based on internal water potential gradients. Using 2D radiography, absolute fluxes of H2O or D2O through the system could not be easily determined since neutron attenuation through the sample was dependent on unknown and dynamic magnitudes of both D and H

  4. Eficiência biológica e econômica de pasto de capim-tanzânia adubado com nitrogênio no final do verão Biological and economic efficiency of Panicum maximum fertilized with nitrogen in the end of summer

    Directory of Open Access Journals (Sweden)

    Valéria Pacheco Batista Euclides

    2007-09-01

    Full Text Available O objetivo deste trabalho foi avaliar o ganho de peso vivo, a capacidade de suporte e a eficiência bioeconômica em pastos de Panicum maximum, cultivar Tanzânia, com aplicação de uma segunda dose de adubação nitrogenada no final do verão. Anualmente foram aplicados em cobertura: 50, 17,48, e 33,2 kg ha-1 de N, P e K, respectivamente, em novembro. A metade da área recebeu 50 kg ha-1 de N adicional em março. Os tratamentos foram pastos de capim-tanzânia com 50 e 100 kg ha-1 de N. Os piquetes foram submetidos ao pastejo rotacionado. Foram utilizados quatro animais por piquete, e animais adicionais foram colocados e removidos para manter resíduos semelhantes pós-pastejo. Não houve efeito da adubação nitrogenada sobre o ganho médio diário. No entanto, o pasto adubado com 100 kg ha-1 de N (1,8 UA ha-1 resultou em maior capacidade de suporte e maior produtividade (780 kg ha-1 por ano de PV do que o adubado com 50 kg ha-1 de N (1,5 UA ha-1 e com 690 kg ha-1 por ano de PV, em média. A eficiência da conversão do N em produto animal foi de 1,8 kg de PV por hectare para cada quilograma adicional de N aplicado. O uso da adubação nitrogenada no final do verão é uma alternativa bioeconomicamente viável para a produção sustentável de carne.The objective of the work was to estimate animal live weight gain, the pasture carrying capacity, and the bioeconomic efficiency of Panicum maximum, cultivar Tanzânia pastures, with a second application of nitrogen fertilizer in the end of summer (March. Maintenance fertilizer was 50, 17.5 and 33.2 kg ha-1 of N, P and K, respectively, applied annually in November. Besides, in half of the area, an additional 50 kg ha-1 of N was applied in March. Treatments were tanzânia pastures with two levels of nitrogen fertilization, 50 and 100 kg ha-1. The paddocks were submitted to a rotational grazing. Four steers were kept in each paddock, and additional steers were allocated and removed to assure similar

  5. Avaliação de três cultivares de Panicum maximum Jacq. sob pastejo: disponibilidade de forragem, altura do resíduo pós-pastejo e participação de folhas, colmos e material morto

    Directory of Open Access Journals (Sweden)

    Brâncio Patrícia Amarante

    2003-01-01

    Full Text Available Três cultivares de Panicum maximum Jacq. submetidos a pastejo rotativo foram avaliados ao longo do ano, antes e após o período de pastejo, quanto às disponibilidades de matéria seca total e de folhas, altura, profundidade pastejada, densidade, participações de folhas, colmos e material morto, relações folha/colmo e folha/material morto. Os tratamentos constituíram em: 1 cv. Tanzânia + 50 kg/ha de N, 2 cv. Tanzânia + 100 kg/ha de N, 3 cv. Mombaça + 50 kg/ha de B e 4 cv. Massai + N 50 kg/ha de N. O cultivar Mombaça apresentou menores disponibilidades de folhas, e maiores proporções de colmo, enquanto o cv. Massai tanto apresentou características que poderiam favorecer a seleção de folhas, como maior densidade de MS e maior relação folha/colmo, como a característica desfavorável de apresentar menor relação folha/material morto. No cv. Tanzânia, a adubação nitrogenada no final do período chuvoso trouxe benefícios apenas em março, quando houve aumento nas relações folha/colmo e folha/material morto. A profundidade pastejada correlacionou-se positivamente com a altura, e os animais pastejaram em média 41% da altura da pastagem, no período seco, e 47% no período chuvoso.

  6. PRODUÇÃO DE MASSA SECA, NÚMERO DE PERFÍLIOS E ÁREA FOLIAR DO CAPIM MOMBAÇA CULTIVADO EM DIFERENTES NÍVEIS DE NITROGÊNIO E FÓSFORO GROUWTH OF Panicum maximum Jacq. Cv. MOMBAÇA UNDER DIFFERENT LEVELS OF NITROGEN AND PHOSPHOROUS IN A GREEN HOUSE

    Directory of Open Access Journals (Sweden)

    Beneval Rosa

    2008-10-01

    Full Text Available

    No presente trabalho avaliaram-se diferentes combinações de doses de nitrogênio e de fósforo na produção de massa seca foliar, número de perfilhos e expansão da área foliar de Panicum maximum Jacq. cv. Mombaça. Para tanto, desenvolveu-se um experimento em casa de vegetação na Escola de Agronomia e Engenharia de Alimentos da Universidade Federal de Goiás. Fez-se uso, como substrato de crescimento, de 7,0 dm3 de terra, acondicionado em vaso plástico de 9,0 dm3 proveniente de um Latossolo Vermelho-escuro distrófico coletado na Fazenda Samambaia no município de Goiânia, GO. Os tratamentos se constituíram da aplicação de quatro doses de nitrogênio na forma de uréia (0, 100, 200 e 400 mg/dm3 de N e quatro doses de fósforo na forma de superfosfato triplo (0, 250, 500 e 750 mg/dm3 de P em quatro repetições. Parcelaram-se as doses de nitrogênio em três aplicações com intervalos de dez dias para cada corte de avaliação. O delineamento experimental foi o inteiramente casualizado com os tratamentos arranjados em um fatorial completo 24 , sendo os fatores as doses de nitrogênio e fósforo. Aos 60 dias após a emergência, efetuou-se um corte de uniformização a 20 cm de altura do solo. Para fins de avaliações, realizaram-se mais três cortes (20 cm de altura a cada trinta dias. Concluiu-se que doses de nitrogênio entre 300 e 400 mg/dm3 de N combinadas com doses de fósforo entre 250 e 500 mg/dm3 de P são as mais indicadas para trabalhos em casa de vegetação com o capim-Mombaça.

    PALAVRAS-CHAVES: Área foliar, capim-Mombaça, massa seca foliar, perfilhos, planta C4.

    The aim of this study was to evaluate the effects of different combinations of nitrogen and phosphorous levels on leaf area, leaf dry matter and tillers number of Panicum maximum Jacq. Cv

  7. Productivity and nutrient cycling in bioenergy cropping systems

    Science.gov (United States)

    Heggenstaller, Andrew Howard

    (Andropogon geradii Vitman), switchgrass (Panicum virgatum L.), indiangrass [ Sorghastrum nutans (L.) Nash], and eastern gamagrass (Tripsacum dactyloides L.). Generally, the optimum rate of fertilization for biomass yield by the grasses was 140 kg N ha-1. Nitrogen inputs also had pronounced but grass-specific effects on biomass and nutrient partitioning, and on carbon storage. For big bluestem and switchgrass, 140 kg N ha -1. maximized root biomass, favored allocation of nutrients to roots over shoots, and led to net increases in carbon storage over the study duration. In contrast, for indiangrass and eastern gamagrass, root biomass and root nutrient allocation were generally adversely affected by N fertilization and carbon storage increased only with 0 or 65 kg N ha-1. For all grasses, 220 kg N ha -1 tended to shift allocation of nutrients to shoots over roots and resulted in no net increase in carbon storage. Optimal nitrogen management strategies for perennial, warm-season grass energy crops should take into consideration the effects of N on biomass yield as well as factors such as nutrient and carbon balance that will also impact economic feasibility and environmental sustainability.

  8. Karyotype studies in Panicum maximum Jacq. | Adedeji | Nigerian ...

    African Journals Online (AJOL)

    No Abstract. Nigerian Journal of Genetics Vol. 18 2003: pp. 5-10. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/njg.v18i1.42284 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More ...

  9. Quality evaluation of little millet (Panicum miliare) incorporated functional bread.

    Science.gov (United States)

    Mannuramath, Mamata; Yenagi, Nirmala; Orsat, Valerie

    2015-12-01

    The study was undertaken with the objective of formulating a fiber enriched functional bread by incorporating little millet flour (LMF). Wheat flour (WF) was replaced with LMF at various proportions (10, 30 and 50%) in the bread preparation. The developed breads were evaluated for physical, sensory and nutritional characteristics. The loaf volume, weight, height and specific volume were decreased significantly with increased levels of LMF. The wheat bread (control), 10 and 30 % percent incorporation of LMF did not show significance difference in the sensory scores. Control and bread with 30 % incorporation of LMF were evaluated further for nutritional characteristics. There was an increase in the percentage of micronutrients such as Iron (94%), Zinc (29%), Copper (70%), Phosphorus (28%) and also fiber (19%) which improved the nutritional value of the wheat bread when substituted with LMF. The incorporation of LMF at 30% level in bread can be considered as a functional and nutritional food choice for the management of diet related metabolic disorders.

  10. An evaluation of Panicum maximum cv. Gatton: 3. The partial ...

    African Journals Online (AJOL)

    Unknown

    quantify the partial digestion of organic matter (OM), nitrogen (N) and neutral detergent fibre (NDF) in sheep .... number of publications have indicated that stage of maturity, as well as level of intake, could have an effect on digestion in the .... large proportion of N in mature pasture is associated with cell walls. This may ...

  11. Anti-nutrient components of guinea grass ( Panicum maximum ...

    African Journals Online (AJOL)

    Yomi

    2012-01-31

    Jan 31, 2012 ... The feeding value of any forage is a function of a number of characteristics of the species, including its availability, accessibility, nutrient availability ... Therefore, the present investigation was carried out to: (1) Evaluate the effect of cutting frequency on anti nutrient factors in P. maximum; (2) assess the effect ...

  12. An evaluation of Panicum maximum cv. Gatton: 3. The partial ...

    African Journals Online (AJOL)

    NDF disappearance from the total tract decreased with increasing pasture maturity during all seasons. It was concluded that P. maximum cv. Gatton pasture would best be utilized at the younger stages of development and that nutritional value would be higher in summer followed by younger autumn and winter pastures.

  13. Influence of growth stage on fermentative characteristics of Panicum ...

    African Journals Online (AJOL)

    p4324129

    ensiling for analysis of ... days 21 and 120 the full bloom stage had a higher acetic acid concentration when the material was directly ..... de-amination of forage proteins and reduce NH3-N production (Woolford, 1984; Jonsson, 1991; Meeske.

  14. Assessment of the phytoremediation potential of Panicum maximum ...

    African Journals Online (AJOL)

    Obvious signs of phyto-toxicity however appeared in plants exposed to 120 ppm Pb2+ and Cd2+ at day twenty-three, suggesting that P. maximum may be a moderate metal accumulator. Keywords: phytoremediation, heavy metals, uptake, tissues, accumulator. African Journal of Biotechnology, Vol 13(19), 1979-1984 ...

  15. Blueberry (Vaccinium virgatum) leaf extracts protect against Aβ-induced cytotoxicity and cognitive impairment.

    Science.gov (United States)

    Jeong, Hee Rok; Jo, Yu Na; Jeong, Ji Hee; Kim, Hyeon Ju; Kim, Man-Jo; Heo, Ho Jin

    2013-11-01

    The ethylacetate (EtOAc) fraction of blueberry leaf extract was investigated to examine the in vivo antiamnesic effects against amyloid β protein (Aβ)-induced learning and memory deficit. The fraction showed the highest antioxidant activities, and the generation of intracellular reactive oxygen species was significantly decreased. Cell viability assays revealed the in vitro cytoprotective effects of the fraction, and the cytoplasmic lactate dehydrogenase release into the medium was dose-dependently inhibited. In addition, a chlorogenic acid was identified as a predominant phenolic compound by high-performance liquid chromatography analysis. Antiamnesic effects were evaluated by using in vivo the Y-maze and passive avoidance tests, and preadministration of the fraction attenuated Aβ-induced memory impairment in both in vivo experiments. Acetylcholinesterase prepared from mice brain was inhibited by the fraction, and malondialdehyde generation in the brain homogenate was also decreased. These findings suggest that the EtOAc fraction of blueberry leaf extract could possess a wide range of physiological effects against neurodegenerative diseases.

  16. Biomass resources for heat and electricity in Greece

    Energy Technology Data Exchange (ETDEWEB)

    Christou, M.; Panoutsou, C. [Center for Renewable Energy Sources (CRES), Pikermi (Greece); Lychnaras, V. [Agricultural Univ. of Greece, Athens (Greece). Laboratory of Agribusiness Management

    2006-07-15

    }/day corresponding to 5.6 PJ annual energy production.Dedicated energy crops have not been commercially established so far. However, some very promising crops have been investigated in several research and development (RandD) programmes, like cardoon (Cynara cardunculus), giant reed (Arundo donax), miscanthus (Miscanthus x sinensis), switchgrass (Panicum virgatum). Productivity varied considerably with site, climate and soil, species and growing techniques, but yields of over 15 dry matter tones/ha/year appear feasible in most of the Greek regions. The reformed CAP is expected to facilitate the integration of dedicated energy crops in the Greek agriculture. In the present study traditional agricultural biomass resources (crop residues in the field and agro-industrial residues) have been listed and their theoretically available quantities and energy content have been assessed. Quantities used for energy production and fuel prices were also recorded where available. Additionally, yields of dedicated for heat and electricity energy crops were assessed, based on data which are a refinement of actual data collected from small and large scale fields, literature and expert estimations. Their energy content was also determined.Logistics and supply chains for the agricultural and energy crops were recorded and economic assessments were made in order to reveal if integration of energy dedicated crops into the local agricultural systems is feasible under the present circumstances as they are influenced by the reformed CAP and could result to significant social and economic benefits (providing additional income to the farmers or maintaining the present one, maintaining jobs in rural areas, etc.), restructuring thus the stagnant agricultural sector at both national and regional level. (Full text of contribution)

  17. Seasonal Soil Nitrogen Mineralization within an Integrated Crop and Livestock System in Western North Dakota, USA

    Science.gov (United States)

    Landblom, Douglas; Senturklu, Songul; Cihacek, Larry; Pfenning, Lauren; Brevik, Eric C.

    2015-04-01

    pipes were pressed into the soil as enclosures to restrict root access to soil nitrogen. Soil samples were taken as close to 2-week intervals as possible from both inside and outside the enclosures. The crop rotation N values were also compared to triple replicated perennial native grassland plot areas (predominate sp. Western wheatgrass - Pascopyrum smithii, Blue grama - Bouteloua gracilis, Little bluestem - Schizachyrium scoparium, Switchgrass - Panicum virgatum). Trends identified for both NH4-N and NO3-N indicate that the values are relatively similar with respect to seasonal change over time. There was a greater amount of soil nitrogen accumulation inside the enclosures indicating that outside the enclosures roots scavenge nitrogen for plant growth and production. Seasonally, comparing the cropping system crops, NO3-N declined mid-July and then rebounded by mid-August and continued to increase until leveling off in September. Corn NO3-N, however, did not follow this pattern, but increased from early June to the end of June and remained high until the first of September. We will present the results of bulk density data and seasonal N fertility data providing evidence for the impact of previous CC on corn production. Probable explanation for the mid-summer nitrogen decline will be presented and justification for reduced fertilizer application will be discussed.

  18. Crop-associated virus reduces the rooting depth of non-crop perennial native grass more than non-crop-associated virus with known viral suppressor of RNA silencing (VSR).

    Science.gov (United States)

    Malmstrom, Carolyn M; Bigelow, Patrick; Trębicki, Piotr; Busch, Anna K; Friel, Colleen; Cole, Ellen; Abdel-Azim, Heba; Phillippo, Colin; Alexander, Helen M

    2017-09-15

    As agricultural acreage expanded and came to dominate landscapes across the world, viruses gained opportunities to move between crop and wild native plants. In the Midwestern USA, virus exchange currently occurs between widespread annual Poaceae crops and remnant native perennial prairie grasses now under consideration as bioenergy feedstocks. In this region, the common aphid species Rhopalosiphum padi L. (the bird cherry-oat aphid) transmits several virus species in the family Luteoviridae, including Barley yellow dwarf virus (BYDV-PAV, genus Luteovirus) and Cereal yellow dwarf virus (CYDV-RPV and -RPS, genus Polerovirus). The yellow dwarf virus (YDV) species in these two genera share genetic similarities in their 3'-ends, but diverge in the 5'-regions. Most notably, CYDVs encode a P0 viral suppressor of RNA silencing (VSR) absent in BYDV-PAV. Because BYDV-PAV has been reported more frequently in annual cereals and CYDVs in perennial non-crop grasses, we examine the hypothesis that the viruses' genetic differences reflect different affinities for crop and non-crop hosts. Specifically, we ask (i) whether CYDVs might persist within and affect a native non-crop grass more strongly than BYDV-PAV, on the grounds that the polerovirus VSR could better moderate the defenses of a well-defended perennial, and (ii) whether the opposite pattern of effects might occur in a less defended annual crop. Because previous work found that the VSR of CYDV-RPS possessed greater silencing suppressor efficiency than that of CYDV-RPV, we further explored (iii) whether a novel grass-associated CYDV-RPS isolate would influence a native non-crop grass more strongly than a comparable CYDV-RPV isolate. In growth chamber studies, we found support for this hypothesis: only grass-associated CYDV-RPS stunted the shoots and crowns of Panicum virgatum L. (switchgrass), a perennial native North American prairie grass, whereas crop-associated BYDV-PAV (and coinfection with BYDV-PAV and CYDV-RPS) most

  19. Using the Model Perennial Grass Brachypodium sylvaticum to Engineer Resistance to Multiple Abiotic Stresses

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Sean; Reguera, Maria; Sade, Nir; Cartwright, Amy; Tobias, Christian; Thilmony, Roger; Blumwald, Eduardo; Vogel, John

    2015-03-20

    We are using the perennial model grass Brachypodium sylvaticum to identify combinations of transgenes that enhance tolerance to multiple, simultaneous abiotic stresses. The most successful transgene combinations will ultimately be used to create improved switchgrass (Panicum virgatum L.) cultivars. To further develop B. sylvaticum as a perennial model grass, and facilitate our planned transcriptional profiling, we are sequencing and annotating the genome. We have generated ~40x genome coverage using PacBio sequencing of the largest possible size selected libraries (18, 22, 25 kb). Our initial assembly using only long-read sequence contained 320 Mb of sequence with an N50 contig length of 315 kb and an N95 contig length of 40 kb. This assembly consists of 2,430 contigs, the largest of which was 1.6 Mb. The estimated genome size based on c-values is 340 Mb indicating that about 20 Mb of presumably repetitive DNA remains yet unassembled. Significantly, this assembly is far superior to an assembly created from paired-end short-read sequence, ~100x genome coverage. The short-read-only assembly contained only 226 Mb of sequence in 19k contigs. To aid the assembly of the scaffolds into chromosome-scale assemblies we produced an F2 mapping population and have genotyped 480 individuals using a genotype by sequence approach. One of the reasons for using B. sylvaticum as a model system is to determine if the transgenes adversely affect perenniality and winter hardiness. Toward this goal, we examined the freezing tolerance of wild type B. sylvaticum lines to determine the optimal conditions for testing the freezing tolerance of the transgenics. A survey of seven accessions noted significant natural variation in freezing tolerance. Seedling or adult Ain-1 plants, the line used for transformation, survived an 8 hour challenge down to -6 oC and 50% survived a challenge down to -9 oC. Thus, we will be able to easily determine if the transgenes compromise freezing tolerance. In the

  20. Switchgrass leaf area index and light extinction coefficients

    Science.gov (United States)

    Biomass production simulation modeling for plant species is often dependent upon accurate simulation or measurement of canopy light interception and radiation use efficiency. With the recent interest in converting large tracts of land to biofuel species cropping, modeling vegetative yield with grea...

  1. Proteomic responses of switchgrass and prairie cordgrass to senescence

    Science.gov (United States)

    Senescence in biofuel grasses is a critical issue because early senescence decreases potential biomass production by limiting aerial growth and development. 2-Dimensional,differential in-gel electrophoresis (2D-DIGE) followed by mass spectrometry of selected protein spots was used to evaluate differ...

  2. Analysis of Factors Affecting Farmers’ Willingness to Adopt Switchgrass Production

    OpenAIRE

    Qualls, D. Joshua; Jensen, Kimberly L.; English, Burton C.; Larson, James A.; Clark, Christopher D.

    2011-01-01

    In the United States, biomass is the largest source of renewable energy accounting for over 3 percent of the energy consumed domestically and is currently the only source for liquid, renewable, transportation fuels. Continued development of biomass as a renewable energy source is being driven in large part by the Energy Independence and Security Act of 2007, which mandates that by 2022 at least 36 billion gallons of fuel ethanol be produced, with at least 16 billion gallons being derived from...

  3. Biofuel intercropping effects on soil carbon and microbial activity.

    Science.gov (United States)

    Strickland, Michael S; Leggett, Zakiya H; Sucre, Eric B; Bradford, Mark A

    2015-01-01

    Biofuels will help meet rising demands for energy and, ideally, limit climate change associated with carbon losses from the biosphere to atmosphere. Biofuel management must therefore maximize energy production and maintain ecosystem carbon stocks. Increasingly, there is interest in intercropping biofuels with other crops, partly because biofuel production on arable land might reduce availability and increase the price of food. One intercropping approach involves growing biofuel grasses in forest plantations. Grasses differ from trees in both their organic inputs to soils and microbial associations. These differences are associated with losses of soil carbon when grasses become abundant in forests. We investigated how intercropping switchgrass (Panicum virgalum), a major candidate for cellulosic biomass production, in loblolly pine (Pinus taeda) plantations affects soil carbon, nitrogen, and microbial dynamics. Our design involved four treatments: two pine management regimes where harvest residues (i.e., biomass) were left in place or removed, and two switchgrass regimes where the grass was grown with pine under the same two biomass scenarios (left or removed). Soil variables were measured in four 1-ha replicate plots in the first and second year following switchgrass planting. Under switchgrass intercropping, pools of mineralizable and particulate organic matter carbon were 42% and 33% lower, respectively. These declines translated into a 21% decrease in total soil carbon in the upper 15 cm of the soil profile, during early stand development. The switchgrass effect, however, was isolated to the interbed region where switchgrass is planted. In these regions, switchgrass-induced reductions in soil carbon pools with 29%, 43%, and 24% declines in mineralizable, particulate, and total soil carbon, respectively. Our results support the idea that grass inputs to forests can prime the activity of soil organic carbon degrading microbes, leading to net reductions in stocks

  4. PRODUTIVIDADE DE CAPIM-MOMBAÇA (Panicum maximum, COM DIFERENTES DOSES DE BIOFERTILIZANTE / MOMBAÇA GRASS PRODUCTIVITY (Panicum maximum, WITH DIFFERENT DOSES OF BIOFERTILIZER

    Directory of Open Access Journals (Sweden)

    A. Simonetti

    2016-03-01

    Full Text Available O presente estudo teve por objetivo verificar a influência da aplicação do dejeto de bovino leiteiro tratados em biodigestores anaeróbios, na forma de biofertilizante, sobre a produtividade da capim Mombaça, em condições de sequeiro.  O trabalho foi conduzido no Instituto de Biotecnologia – IBIOTEC, pertencente à UNIARA, Araraquara – SP. Para obtenção do biofertilizante, foi feita a diluição dos dejetos em água e armazenado em um biodigestor modelo indiano de fibra de vidro com capacidade útil de 1000 L, instalado no referido instituto. As fertilizações foram feitas a lanço após cada rebaixamento das parcelas. O delineamento utilizado foi em blocos casualizados, com quatro tratamentos e quatro repetições, com diferentes doses do biofertilizante, sendo: 0; 50m³; 100m³ e 200m³/ha-1.  As variáveis avaliadas foram: altura, produção por hectare (matéria seca e matéria verde, e qualidade bromatológica. Foram observados que os tratamentos que receberam a maior dosagem de biofertilizante, apresentaram maiores valores para produtividade Matéria Seca, Matéria Verde e teor de proteína. Conclui-se que a aplicação de biofertilizante é benéfico ao sistema de pastagem, porém suas doses devem ser estudadas e a sua resposta na produção pode obtidas a longo prazo.

  5. GRASS SPECIES FROM C-4 CARBON FIXATION GROUP: POLISH EXPERIMENT WITH A NOVEL ENERGY AND FORAGE PURPOSES CROP

    Directory of Open Access Journals (Sweden)

    Włodzimierz Majtkowski

    2010-02-01

    Full Text Available Experiment was conducted during four years 2003-2006. Materials used were three genus grass species of C-4 photosynthesis: Andropogon gerardi Vitman, Panicum virgatum L. and Miscanthus sacchariflorus (Maxim. Hack. Plants were planted at spring 1998. Agrotechnical part of experiment was conducted in Botanical Garden of Plant Breeding Acclimatization Institute in Bydgoszcz and analytical part in Department of Animal Nutrition and Feed Management, Faculty of Animal Breeding and Biology of University of Technology and Life Science in Bydgoszcz. Forage from grass C-4 photosynthesis were material of good ensilage suitability. High structural carbohydrates (NDF, ADF contents in tested forage dry matter suggest ensilage at early phases of plant development. Above results suggest to possibility of usage of forage from grass C-4 carbon fixation group for animal feeding purposes. C-4 grass forage should be recognized as a supplementary source of green matter in periods of insufficient access to traditional silage sources.

  6. Croissance pré-sevrage des cobayes nourris au Panicum maximum ...

    African Journals Online (AJOL)

    L'objectif de ce travail est donc d'améliorer l'alimentation de ces animaux à travers la diversification des sources de protéine de la ration. Pour cet essai, 48 femelles ont préalablement été mises en croisement avec 8 mâles pendant une période de 31 jours selon un dispositif factoriel de quatre lots comptant 12 femelles ...

  7. Phenotypic Responses of Twenty Diverse Proso Millet (Panicum miliaceum L. Accessions to Irrigation

    Directory of Open Access Journals (Sweden)

    Cedric Habiyaremye

    2017-03-01

    Full Text Available To date, little research has been conducted on the phenotypic responses of proso millet to drought and deficit irrigation treatments in the dryland wheat-based cropping systems of the Palouse bioregion of the U.S. The objectives of this study were to evaluate critical agronomic traits of proso millet, including emergence, plant height, days to heading, days to maturity, and grain yield, with and without supplemental irrigation. Twenty diverse proso millet accessions, originating from Bulgaria, Czechoslovakia, Morocco, the former Soviet Union, Turkey, and the United States, were grown in irrigated and non-irrigated treatments under organic conditions in Pullman, WA, from 2012 to 2014. Irrigation was shown to significantly improve emergence and increase plant height at stem extension and to hasten ripening of all the varieties, whereas heading date was not affected by irrigation in two of the three years tested. Irrigation resulted in higher mean seed yield across all varieties, with ‘GR 665’ and ‘Earlybird’ performing best under irrigation. Seed yield was highest in ‘GR 658’ and ‘Minsum’ in the non-irrigated treatment, suggesting the importance of identification and utilization of varieties adapted to low rainfall conditions. The highest yielding varieties in irrigated systems are unlikely be the highest yielding in dryland systems. Our results suggest that millet has potential as a regionally novel crop for inclusion in traditional dryland cropping rotations in the Palouse ecosystem, thereby contributing to increased cropping system diversity.

  8. An evaluation of Panicum maximum cv. Gatton: 2. The influence of ...

    African Journals Online (AJOL)

    -N) levels and higher acetic:propionic acid ratios. This trend was noted in all seasons. The nutritional value of the pasture in summer was high enough to meet at least the maintenance requirements of sheep in all stages of maturity evaluated.

  9. An evaluation of Panicum maximum cv. Gatton: 2. The influence of ...

    African Journals Online (AJOL)

    Unknown

    maturity on diet selection, intake and rumen fermentation in sheep. E.A. Relling, W.A. ... The stage of maturity of pasture influences forage quality and hence voluntary intake and selection by sheep. ..... dry matter production of some improved pastures and animal performance in relation to chemical composition in Malawi.

  10. Accumulation of 137Cs and 90Sr from contaminated soil by three grass species inoculated with mycorrhizal fungi

    International Nuclear Information System (INIS)

    Entry, J.A.; Watrud, L.S.; Reeves, M.

    1999-01-01

    The use of plants to accumulate low level radioactive waste from soil, followed by incineration of plant material to concentrate radionuclides may prove to be a viable and economical method of remediating contaminated areas. We tested the influence of arbuscular mycorrhizae on 137 Cs and 90 Sr uptake by bahia grass (Paspalum notatum), johnson grass (Sorghum halpense) and switchgrass (Panicum virginatum) for the effectiveness on three different contaminated soil types. Exposure to 137 Cs or 90 Sr over the course of the experiment did not affect above ground biomass of the three grasses. The above ground biomass of bahia, johnson and switchgrass plants accumulated from 26.3 to 71.7% of the total amount of the 137 Cs and from 23.8 to 88.7% of the total amount of the 90 Sr added to the soil after three harvests. In each of the three grass species tested, plants inoculated with Glomus mosseae or Glomus intraradices had greater aboveground plant biomass, higher concentrations of 137 Cs or 90 Sr in plant tissue, % accumulation of 137 Cs or 90 Sr from soil and plant bioconcentration ratios at each harvest than those that did not receive mycorrhizal inoculation. Johnson grass had greater aboveground plant biomass, greater accumulation of 137 Cs or 90 Sr from soil and plant higher bioconcentration ratios with arbuscular mycorrhizal fungi than bahia grass and switchgrass. The greatest accumulation of 137 Cs and 90 Sr was observed in johnson grass inoculated with G. mosseae. Grasses can grow in wide geographical ranges that include a broad variety of edaphic conditions. The highly efficient removal of these radionuclides by these grass species after inoculation with arbuscular mycorrhizae supports the concept that remediation of radionuclide contaminated soils using mycorrhizal plants may present a viable strategy to remediate and reclaim sites contaminated with radionuclides

  11. Genetic diversity among proso millet (Panicum miliaceum biotypes assessed by AFLP technique Diversidade genética entre biótipos de proso millet (Panicum miliaceum revelada pela técnica de AFLP

    Directory of Open Access Journals (Sweden)

    D. Karam

    2004-06-01

    Full Text Available The Amplified Fragment Length Polymorphism (AFLP technique was used to access genetic diversity between three domestic and nine wild proso millet biotypes from the United States and Canada. Eight primer combinations detected 39 polymorphic DNA fragments, with the genetic distance estimates among biotypes ranging from 0.02 to 0.04. Colorado-Weld County black seeded and Wyoming-Platte County were the most distinct biotypes according to the dissimilarity level. A UPGMA cluster analysis revealed two distinct groups of proso millet without any geographic association. Six weed biotypes exhibiting some characters of cultivated plants were grouped together with domesticated biotypes of proso millet while the three typical wild phenotypes were clearly clustered into another group according to AFLP markers.A técnica de AFLP (Amplified Fragment Length Polymorphism foi empregada para acessar a diversidade genética entre três biótipos domesticados e nove biótipos selvagens de proso millet dos Estados Unidos e do Canadá. Oito combinações de primers detectaram 39 fragmentos polimórficos de DNA, e a estimativa da distância genética entre os biótipos variou de 0,02 a 0,04. Colorado-Weld County de sementes pretas e Wyoming-Platte County foram os biótipos mais distintos de acordo com o índice de dissimilaridade. A análise de cluster por UPGMA revelou dois grupos distintos de proso millet mas sem nenhuma relação geográfica. Seis biótipos selvagens que exibiam algumas características de plantas cultivadas foram agrupados juntamente com os biótipos domesticados de proso millet, enquanto os três fenótipos tipicamente selvagens formaram outro grupo distinto por marcadores AFLP.

  12. Evaluation of biogas production by dry anaerobic digestion of switchgrass-animal manure mixtures

    Science.gov (United States)

    Anaerobic digestion is a biological method used to convert organic wastes into a stable product for land application without adverse environmental effects. The biogas produced can be used as an alternative renewable energy source. Dry anaerobic digestion (> 15% TS; total solid) has an advantage ov...

  13. All washed out? Foliar nutrient resorption and leaching in senescing switchgrass

    Science.gov (United States)

    Ideal bioenergy feedstocks are low in nutrients that act as anti-quality factors during conversion processes. Research has shown that delaying harvest of temperate perennial grasses until late winter reduces nutrient content, primarily due to end-season resorption, but also indicates a role for foli...

  14. Development of Kinetics and Mathematical Models for High Pressure Gasification of Lignite-Switchgrass Blends

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Pradeep K. [Georgia Inst. of Technology, Atlanta, GA (United States). School of Chemical and Biomolecular Engineering

    2016-12-20

    The overall objective of the current project was to investigate the high pressure gasification characteristics of a feed containing both coal and biomass. The two feed types differ in their ash contents and ash composition, particularly the alkali content. Gasification of a combined feed of coal and biomass has the potential for considerable synergies that might lead to a dramatic improvement in process economics and flexibility. The proposed study aimed to develop a detailed understanding of the chemistry, kinetics, and transport effects during high pressure gasification of coal-biomass blend feed. Specifically, we studied to develop: (a) an understanding of the catalytic effect of alkali and other inorganic species present in the biomass and coal, (b) an understanding of processing conditions under which synergistic effects of the blending of coal and biomass might be observed. This included the role of particle size, residence time, and proximity of the two feed types, (c) kinetics of high pressure gasification of individual feeds as well as the blends, and (d) development of mathematical models that incorporate kinetics and transport models to enable prediction of gasification rate at a given set of operating conditions, and (e) protocols to extend the results to other feed resources. The goal was to provide a fundamental understanding of the gasification process and guide in optimizing the configurations and design of the next generation of gasifiers. The approach undertaken was centered on two basic premises: (1) the gasification for small particles without internal mass transfer limitations can be treated as the sum of two processes in series (pyrolysis and char gasification) , and (2) the reactivity of the char generated during pyrolysis not only depends on the pressure and temperature but is also affected by the heating rates. Thus low heating rates (10-50 °C/min) typical of PTGA fail to produce char that would typically be formed at high heating rates (~104 °C/sec), encountered in entrained flow gasifiers. The char morphology, also a function of the heating rate, would influence the transport rates during the char gasification phase. Thus, heating rate plays a critical role through which both, pyrolysis and char gasification, are interconnected. We utilized two complementary gasification experiments: PEFR (pressurized entrained flow gasifier) and PTGA (pressurized thermo-gravimetric analyzer). The PEFR allowed us to study gasification at pressures, temperatures, and heating rates relevant for coal-biomass gasifiers. The PTGA work was useful in understanding the basic chemistry of the evolution of various gaseous species during pyrolysis. These results helped improved our understanding of the chemistry and chemical changes during pyrolysis. The role alkali metals and other inorganics in char gasification using steam and/or CO2 was investigated. Finally, the mathematical models for char gasification without the transport effects were developed at commercial operating conditions.

  15. Engineering Saccharomyces cerevisiae to produce feruloyl esterase for the release of ferulic acid from switchgrass

    Science.gov (United States)