WorldWideScience

Sample records for california perennial crop

  1. Impacts of Future Climate Change on California Perennial Crop Yields: Model Projections with Climate and Crop Uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Lobell, D; Field, C; Cahill, K; Bonfils, C

    2006-01-10

    Most research on the agricultural impacts of climate change has focused on the major annual crops, yet perennial cropping systems are less adaptable and thus potentially more susceptible to damage. Improved assessments of yield responses to future climate are needed to prioritize adaptation strategies in the many regions where perennial crops are economically and culturally important. These impact assessments, in turn, must rely on climate and crop models that contain often poorly defined uncertainties. We evaluated the impact of climate change on six major perennial crops in California: wine grapes, almonds, table grapes, oranges, walnuts, and avocados. Outputs from multiple climate models were used to evaluate climate uncertainty, while multiple statistical crop models, derived by resampling historical databases, were used to address crop response uncertainties. We find that, despite these uncertainties, climate change in California is very likely to put downward pressure on yields of almonds, walnuts, avocados, and table grapes by 2050. Without CO{sub 2} fertilization or adaptation measures, projected losses range from 0 to >40% depending on the crop and the trajectory of climate change. Climate change uncertainty generally had a larger impact on projections than crop model uncertainty, although the latter was substantial for several crops. Opportunities for expansion into cooler regions are identified, but this adaptation would require substantial investments and may be limited by non-climatic constraints. Given the long time scales for growth and production of orchards and vineyards ({approx}30 years), climate change should be an important factor in selecting perennial varieties and deciding whether and where perennials should be planted.

  2. Soil erosion: perennial crop plantations

    NARCIS (Netherlands)

    Hartemink, A.E.

    2006-01-01

    Plantation agriculture is an important form of land-use in the tropics. Large areas of natural and regenerated forest have been cleared for growing oil palm, rubber, cocoa, coffee, and other perennial tree crops. These crops grown both on large scale plantations and by smallholders are important

  3. Nigeria: macroeconomic environment and the perennial crops ...

    African Journals Online (AJOL)

    This paper examines the impacts of macroeconomic environment on the output performances of perennial crops – namely cocoa, rubber, palm oil and palm kernel in Nigeria. The time series data used for the analysis reveals agricultural policy/programme instability. Ordinary Least Square estimation shows that most ...

  4. Agroecology of Novel Annual and Perennial Crops for Biomass Production

    DEFF Research Database (Denmark)

    Manevski, Kiril; Jørgensen, Uffe; Lærke, Poul Erik

    The agroecological potential of many crops under sustainable intensification has not been investigated. This study investigates such potential for novel annual and perennial crops grown for biomass production.......The agroecological potential of many crops under sustainable intensification has not been investigated. This study investigates such potential for novel annual and perennial crops grown for biomass production....

  5. Impact of cash cropping and perennial crops on food crop ...

    African Journals Online (AJOL)

    synergies or trade-offs between the two crops are scant to address the concerns that cash cropping can ..... production and productivity, we develop indices of intensity of PCC and enset cultivation. We define household i's ... study the impact of these indices on food crop production and productivity, we specify models for i.

  6. Impact of cash cropping and perennial crops on food crop ...

    African Journals Online (AJOL)

    Increased crop production and sale of part of production during the main harvest season led households to ... Ethiopia, crop income accounts for the largest share of total income, 71%, followed by share of off-farm ... and Olinto (2001), in Colombia, off-farm employment contributes a significant share. (45%) to household ...

  7. Crop rotation and its ability to suppress perennial weeds

    OpenAIRE

    Askegaard, Margrethe

    2016-01-01

    The appropriate combination of crops and green manures prevents spread of perennial weeds and increases crop yields and quality. Weed-suppressing crop rotations are absolutely essential for sustainable organic arable farming. Practical recommendation Basic rules • Implement green manures, such as clover or lucerne, in at least 20 % of the rotation. • Do not grow more than 50 % of cereals with low weed competitiveness in the rotation. Do not cultivate such crops for more than 2 con...

  8. Nigeria: macroeconomic environment and the perennial crops ...

    African Journals Online (AJOL)

    Ordinary Least Square estimation shows that most macroeconomic policy variables – exchange rate, interest rate, government expenditure, credit are negatively related to outputs. Technological change and policy shift variables are negative for cocoa but positive for other crops. Collectively, the variables explain between ...

  9. Perennial forages as second generation bioenergy crops.

    Science.gov (United States)

    Sanderson, Matt A; Adler, Paul R

    2008-05-01

    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.

  10. Energizing marginal soils: A perennial cropping system for Sida hermaphrodita

    Science.gov (United States)

    Nabel, Moritz; Poorter, Hendrik; Temperton, Vicky; Schrey, Silvia D.; Koller, Robert; Schurr, Ulrich; Jablonowski, Nicolai D.

    2017-04-01

    As a way to avoid land use conflicts, the use of marginal soils for the production of plant biomass can be a sustainable alternative to conventional biomass production (e.g. maize). However, new cropping strategies have to be found that meet the challenge of crop production under marginal soil conditions. We aim for increased soil fertility by the use of the perennial crop Sida hermaphrodita in combination with organic fertilization and legume intercropping to produce substantial biomass yield. We present results of a three-year outdoor mesocosm experiment testing the perennial energy crop Sida hermaphrodita grown on a marginal model substrate (sand) with four kinds of fertilization (Digestate broadcast, Digestate Depot, mineral NPK and unfertilized control) in combination with legume intercropping. After three years, organic fertilization (via biogas digestate) compared to mineral fertilization (NPK), reduced the nitrate concentration in leachate and increased the soil carbon content. Biomass yields of Sida were 25% higher when fertilized organically, compared to mineral fertilizer. In general, digestate broadcast application reduced root growth and the wettability of the sandy substrate. However, when digestate was applied locally as depot to the rhizosphere, root growth increased and the wettability of the sandy substrate was preserved. Depot fertilization increased biomass yield by 10% compared to digestate broadcast fertilization. We intercropped Sida with various legumes (Trifolium repens, Trifolium pratense, Melilotus spp. and Medicago sativa) to enable biological nitrogen fixation and make the cropping system independent from synthetically produced fertilizers. We could show that Medicago sativa grown on marginal substrate fixed large amounts of N, especially when fertilized organically, whereas mineral fertilization suppressed biological nitrogen fixation. We conclude that the perennial energy crop Sida in combination with organic fertilization has great

  11. Tradeoffs between water requirements and yield stability in annual vs. perennial crops

    Science.gov (United States)

    Vico, Giulia; Brunsell, Nathaniel A.

    2018-02-01

    Population growth and changes in climate and diets will likely further increase the pressure on agriculture and water resources globally. Currently, staple crops are obtained from annuals plants. A shift towards perennial crops may enhance many ecosystem services, but at the cost of higher water requirements and lower yields. It is still unclear when the advantages of perennial crops overcome their disadvantages and perennial crops are thus a sustainable solution. Here we combine a probabilistic description of the soil water balance and crop development with an extensive dataset of traits of congeneric annuals and perennials to identify the conditions for which perennial crops are more viable than annual ones with reference to yield, yield stability, and effective use of water. We show that the larger and more developed roots of perennial crops allow a better exploitation of soil water resources and a reduction of yield variability with respect to annual species, but their yields remain lower when considering grain crops. Furthermore, perennial crops have higher and more variable irrigation requirements and lower water productivity. These results are important to understand the potential consequences for yield, its stability, and water resource use of a shift from annual to perennial crops and, more generally, if perennial crops may be more resilient than annual crops in the face of climatic fluctuations.

  12. Modelling farmer uptake of perennial energy crops in the UK

    Energy Technology Data Exchange (ETDEWEB)

    Sherrington, Chris; Moran, Dominic [Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG (United Kingdom)

    2010-07-15

    The UK Biomass Strategy suggests that to reach the technical potential of perennial energy crops such as short rotation coppice (SRC) willow and miscanthus by 2020 requires 350,000 hectares of land. This represents a more than 20-fold increase on the current 15,546 hectares. Previous research has identified several barriers to adoption, including concerns over security of income from contracts. In addition, farmers perceive returns from these crops to be lower than for conventional crops. This paper uses a farm-level linear programming model to investigate theoretical uptake of energy crops at different gross margins under the assumption of a profit-maximising decision maker, and in the absence of known barriers to adoption. The findings suggest that while SRC willow, at current prices, remains less competitive, returns to miscanthus should have encouraged adoption on a wider scale than at present. This highlights the importance of the barriers to adoption. Recently announced contracts for miscanthus appear to offer a significant premium to farmers in order to encourage them to grow the crops. This raises the question of whether a more cost-effective approach would be for government to provide guarantees addressing farmers concerns including security of income from the contracts. Such an approach should encourage adoption at lower gross margins. (author)

  13. Can exotic phytoseiids be considered 'benevolent invaders' in perennial cropping systems?

    Science.gov (United States)

    Palevsky, Eric; Gerson, Uri; Zhang, Zhi-Qiang

    2013-02-01

    Numerous natural enemies were adopted worldwide for the control of major pests, including exotic phytoseiid species (Acari: Mesostigmata: Phytoseiidae) that had been moved from continent to continent in protected and perennial agricultural systems. However, relatively fewer successes were recorded in perennial agricultural systems. In this manuscript we focus on the question: Can and will exotic phytoseiids provide better pest control than indigenous species in perennial agricultural systems? To answer this question, we review the efficacy of biological control efforts with phytoseiids in several case studies, where exotic and indigenous species were used against pests on indigenous host plants and some crops that were historically or recently introduced. Related factors affecting predator establishment, such as intraguild predation and pesticide effects are discussed, as well as the potential negative effects of exotic species releases on biological control and their impact on the indigenous natural fauna. On citrus, apple, grape and cassava exotic phytoseiids have enhanced biological control without negatively affecting indigenous species of natural enemies, except for the case of Euseius stipulatus (Athias-Henriot) on citrus that displaced Euseius hibisci (Chant) in a limited region of coastal California, USA, the latter considered to be an inferior biocontrol agent of Panonychus citri Koch. Phytoseiulus persimilis Athias-Henriot on gorse, an invasive weed, is perhaps the only recorded case of a negative effect of an established exotic phytoseiid on biological control.

  14. Integration of annual and perennial cover crops for improving soil health

    Science.gov (United States)

    Annual and perennial cover crops in rotation provide environmental services and benefit soil health. Environmentally, cover crops can fill gaps in the rotation where the field may otherwise be fallow, thereby reducing soil erosion. Additionally, using cover crops as a nutrient capture tool can red...

  15. High quality reference genome of drumstick tree (Moringa oleifera Lam.), a potential perennial crop

    National Research Council Canada - National Science Library

    Tian, Yang; Zeng, Yan; Zhang, Jing; Yang, ChengGuang; Yan, Liang; Wang, XuanJun; Shi, ChongYing; Xie, Jing; Dai, TianYi; Peng, Lei; Zeng Huan, Yu; Xu, AnNi; Huang, YeWei; Zhang, JiaJin; Ma, Xiao; Dong, Yang; Hao, ShuMei; Sheng, Jun

    2015-01-01

    The drumstick tree (Moringa oleifera Lam.) is a perennial crop that has gained popularity in certain developing countries for its high-nutrition content and adaptability to arid and semi-arid environments...

  16. Energy balance and cost-benefit analysis of biogas production from perennial energy crops pretreated by wet oxidation

    DEFF Research Database (Denmark)

    Uellendahl, Hinrich; Wang, Guangtao; Møller, H.B.

    2008-01-01

    . The conversion into biogas in anaerobic digestion plants shows however much lower specific methane yields for the raw perennial crops like miscanthus and willow due to their lignocellulosic structure. Without pretreatment the net energy gain is therefore lower for the perennials than for corn. When applying wet......Perennial crops need far less energy to plant, require less fertilizer and pesticides, and show a lower negative environmental impact compared with annual crops like for example corn. This makes the cultivation of perennial crops as energy crops more sustainable than the use of annual crops...... oxidation to the perennial crops, however, the specific methane yield increases significantly and the ratio of energy output to input and of costs to benefit for the whole chain of biomass supply and conversion into biogas becomes higher than for corn. This will make the use of perennial crops as energy...

  17. Energy balance and cost-benefit analysis of biogas production from perennial energy crops pretreated by wet oxidation

    DEFF Research Database (Denmark)

    Uellendahl, Hinrich; Wang, Guangtao; Møller, Henrik B.

    2008-01-01

    Perennial crops need far less energy to plant, require less fertilizer and pesticides, and show a lower negative environmental impact compared with annual crops like for example corn. This makes the cultivation of perennial crops as energy crops more sustainable than the use of annual crops....... The conversion into biogas in anaerobic digestion plants shows however much lower specific methane yields for the raw perennial crops like miscanthus and willow due to their lignocellulosic structure. Without pretreatment the net energy gain is therefore lower for the perennials than for corn. When applying wet...... oxidation to the perennial crops, however, the specific methane yield increases significantly and the ratio of energy output to input and of costs to benefit for the whole chain of biomass supply and conversion into biogas becomes higher than for corn. This will make the use of perennial crops as energy...

  18. A Systematic Review of Perennial Staple Crops Literature Using Topic Modeling and Bibliometric Analysis.

    Directory of Open Access Journals (Sweden)

    Daniel A Kane

    Full Text Available Research on perennial staple crops has increased in the past ten years due to their potential to improve ecosystem services in agricultural systems. However, multiple past breeding efforts as well as research on traditional ratoon systems mean there is already a broad body of literature on perennial crops. In this review, we compare the development of research on perennial staple crops, including wheat, rice, rye, sorghum, and pigeon pea. We utilized the advanced search capabilities of Web of Science, Scopus, ScienceDirect, and Agricola to gather a library of 914 articles published from 1930 to the present. We analyzed the metadata in the entire library and in collections of literature on each crop to understand trends in research and publishing. In addition, we applied topic modeling to the article abstracts, a type of text analysis that identifies frequently co-occurring terms and latent topics. We found: 1. Research on perennials is increasing overall, but individual crops have each seen periods of heightened interest and research activity; 2. Specialist journals play an important role in supporting early research efforts. Research often begins within communities of specialists or breeders for the individual crop before transitioning to a more general scientific audience; 3. Existing perennial agricultural systems and their domesticated crop material, such as ratoon rice systems, can provide a useful foundation for breeding efforts, accelerating the development of truly perennial crops and farming systems; 4. Primary research is lacking for crops that are produced on a smaller scale globally, such as pigeon pea and sorghum, and on the ecosystem service benefits of perennial agricultural systems.

  19. Contrasting weed species composition in perennial alfalfas and six annual crops: implications for integrated weed management

    OpenAIRE

    Meiss, Helmut; Médiène, Safia; Waldhardt, Rainer; Caneill, Jacques; Munier-Jolain, Nathalie

    2010-01-01

    International audience; Weed communities are most strongly affected by the characteristics and management of the current crop. Crop rotation may thus be used to prevent the repeated selection of particular weed species. While weed communities are frequently compared among annual crops, little is known about the differences between annual and perennial crops that may be included in the rotations. Moreover, nearly all existing studies (17 articles reviewed) are based on local field experiments ...

  20. A generic model for estimating biomass accumulation and greenhouse gas emissions from perennial crops

    Science.gov (United States)

    Ledo, Alicia; Heathcote, Richard; Hastings, Astley; Smith, Pete; Hillier, Jonathan

    2017-04-01

    Agriculture is essential to maintain humankind but is, at the same time, a substantial emitter of greenhouse gas (GHG) emissions. With a rising global population, the need for agriculture to provide secure food and energy supply is one of the main human challenges. At the same time, it is the only sector which has significant potential for negative emissions through the sequestration of carbon and offsetting via supply of feedstock for energy production. Perennial crops accumulate carbon during their lifetime and enhance organic soil carbon increase via root senescence and decomposition. However, inconsistency in accounting for this stored biomass undermines efforts to assess the benefits of such cropping systems when applied at scale. A consequence of this exclusion is that efforts to manage this important carbon stock are neglected. Detailed information on carbon balance is crucial to identify the main processes responsible for greenhouse gas emissions in order to develop strategic mitigation programs. Perennial crops systems represent 30% in area of total global crop systems, a considerable amount to be ignored. Furthermore, they have a major standing both in the bioenergy and global food industries. In this study, we first present a generic model to calculate the carbon balance and GHGs emissions from perennial crops, covering both food and bioenergy crops. The model is composed of two simple process-based sub-models, to cover perennial grasses and other perennial woody plants. The first is a generic individual based sub-model (IBM) covering crops in which the yield is the fruit and the plant biomass is an unharvested residue. Trees, shrubs and climbers fall into this category. The second model is a generic area based sub-model (ABM) covering perennial grasses, in which the harvested part includes some of the plant parts in which the carbon storage is accounted. Most second generation perennial bioenergy crops fall into this category. Both generic sub

  1. A realistic meteorological assessment of perennial biofuel crop deployment: a southern Great Plains perspective

    Science.gov (United States)

    Utility of perennial bioenergy crops (e.g., switchgrass and miscanthus) offer unique opportunities to transition toward a more sustainable energy pathway due to their reduced carbon footprint, averted competition with food crops, and ability to grow on abandoned and degraded farmlands. Studies that ...

  2. Investigating hydrometeorological impacts of perennial bioenergy crops under realistic scenario expansions

    Science.gov (United States)

    Wagner, M.; Wang, M.; Miguez-Macho, G.; Miller, J. N.; Bagley, J. E.; Bernacchi, C.; Georgescu, M.

    2016-12-01

    Perennial bioenergy crops, such as switchgrass and miscanthus, have been posed as a more sustainable energy pathway relative to annual bioenergy crops due to their reduced carbon footprint and ability to grow on abandoned and degraded land, thereby, avoiding competition with food crops. Previous studies that replaced annual bioenergy crops with perennial crops noted regional cooling associated with enhanced ET due to their deeper rooting systems extracting deeper soil moisture. This study provides a more realistic assessment by (1) analyzing perennial bioenergy expansion only in suitable abandoned and degraded farmlands, and (2) using field scale measurements of albedo in conjunction with known vegetation fraction and leaf area index (LAI) values. High-resolution (2 km grid spacing) simulations were performed using a state-of-the-art atmospheric model (Weather Research and Forecasting system) dynamically coupled to a land surface model system over the Southern Plains of the U.S., during a normal precipitation year (2007) and a drought year (2011). Our results show that perennial bioenergy crop expansion leads to regional cooling (1-2 oC), that is driven primarily by enhanced reflection of shortwave radiation, and secondarily, by enhanced ET. Perennial bioenergy crop expansion was also shown to mitigate drought impacts through moistening and cooling of the near-surface environment. These impacts, however, were reduced during the drought year as a result of differential environmental conditions, when compared to those of the normal cimate year. This study serves as a major step towards assessing the sustainability of perennial bioenergy crop expansion under diverse hydrometeorological conditions by highlighting the driving mechanisms and processes associated with this energy pathway.

  3. Weed management in short rotation poplar and herbaceous perennial crops grown for biofuel production

    Energy Technology Data Exchange (ETDEWEB)

    Buhler, D.D. [USDA-Agricultural Research Service National Soil Tilth Lab., Ames, IA (United States); Netzer, D.A.; Riemenschneider, D.E. [USDA-Forest Service, Forestry Sciences Lab., Rhinelander, WI (United States); Hartzler, R.G. [Iowa State Univ., Ames, IA (United States). Dept. of Agrimony

    1998-12-31

    Weed management is a key element of any crop production system. Weeds are a particular problem in the production of short rotation woody and perennial herbaceous biomass crops due to the shortage of registered herbicides and integrated weed management systems. Herbicides will be an important component of weed management of biomass crops. However, producers should take a broader view of weeds and incorporate all available weed management tactics in these production systems. In both short rotation poplar and herbaceous perennial crops, weed control during the establishment period is most critical. New plantings of these species grow very slowly and do not compete well with weeds until a canopy develops. Effective weed control can double the growth of short rotation poplar crops and affect the variability of the resulting stand. In crops like switchgrass, uncontrolled weeds during establishment can result in stand failure. Cultural practices such as site preparation, using weed-free seed, fallowing, selecting the proper planting dates, companion crops and controlling weeds in previous crops must be combined with herbicides to develop integrated management systems. Weeds may also cause problems in established stands through competition with the biomass crop and by contaminating the product. Effective and economical weed management systems will be essential for the development of short rotation woody and herbaceous perennial biomass crop production systems. (Author)

  4. Medium-term effect of perennial energy crops on soil organic carbon storage

    Directory of Open Access Journals (Sweden)

    Enrico Ceotto

    2011-11-01

    Full Text Available The scope of this study was to evaluate the effect of perennial energy crops on soil organic carbon (SOC storage. A field experiment was undertaken in 2002 at Anzola dell’Emilia in the lower Po Valley, Northern Italy. Five perennial energy crops were established on a land area which had been previously cultivated with arable crops for at least 20 years. The compared crops are: the herbaceous perennials giant reed and miscanthus, and the woody species poplar, willow and black locust, managed as short rotation coppice (SRC. SOC was measured in 2009, seven years after the start of the experiment, on an upper soil layer of 0.0-0.2 m and a lower soil layer of 0.2-0.4 m. The study aimed to compare the SOC storage of energy crops with alternative land use. Therefore, two adjacent areas were sampled in the same soil layers: i arable land in steady state, cultivated with rainfed annual crops; ii natural meadow established at the start of the experiment. The conversion of arable land into perennial energy crops resulted in SOC storage, in the upper soil layer (0.0-0.2 m ranging from 1150 to 1950 kg C ha-1 year-1 during the 7-year period. No significant differences were detected in SOC among crop species. We found no relationship between the harvested dry matter and the SOC storage. The conversion of arable land into perennial energy crops provides a substantial SOC sequestration benefit even when the hidden C cost of N industrial fertilizers is taken into account. While the SOC increased, the total N content in the soil remained fairly constant. This is probably due to the low rate of nitrogen applied to the perennial crops. However, our data are preliminary and the number of years in which the SOC continues to increase needs to be quantified, especially for the herbaceous species giant reed and miscanthus, with a supposedly long duration of the useful cropping cycle of 20 years or longer.

  5. Impact of perennial cash croppin on food crop productivity. | Debela ...

    African Journals Online (AJOL)

    The argument for promoting cash crops in developing countries has generally been based on their contribution to small farmer incomes and their impact on other household activities such as household crop production through interlinked markets. While these arguments are supported by some empirical results, there is little ...

  6. Impact of perennial cash croppin on food crop productivity. | Debela ...

    African Journals Online (AJOL)

    ... production through cash income and its impact on food crops, coffee and enset can be produced to bring additional income to the household at no significant cost to food crops. The real impact of chat on the welfare of households should be viewed in terms of its opportunity costs and its contribution to household income.

  7. Italian ryegrass as a perennial fodder crop. | C.A.H. | African Journal ...

    African Journals Online (AJOL)

    Italian ryegrass (Lolium multiflorum Lam.) may be re-established from seedfall if the appropriate management practices are applied, and may thus function as a perennial fodder crop. Annual seedbed preparation and seeding are eliminated in this way. Keywords: botany; fodder; grasses; italian ryegrass; lolium multiflorum; ...

  8. Candidate perennial bioenergy grasses have a higher albedo than annual row crops in the Midwestern US

    Science.gov (United States)

    The production of perennial cellulosic feedstocks for bioenergy presents the potential to diversify regional economies and the national energy supply, while also serving as climate ‘regulators’ due to a number of biogeochemical and biogeophysical differences relative to row crops. Numerous observati...

  9. A multi-scale hydroclimatological assessment of perennial bioenergy cropping systems

    Science.gov (United States)

    Georgescu, Matei; Miguez-Macho, Gonzalo; Wagner, Melissa; Wang, Meng; Bagley, Justin; Vanloocke, Andrew

    2017-04-01

    Hydro-climatic sustainability associated with deployment of perennial bioenergy cropping systems requires a holistic approach that extends beyond merely carbon accounting. Here, we present results from a five-year National Science Foundation project (Water Sustainability and Climate initiative) focused on development of geographically explicit maps depicting sustainable regional "hot-spots" of perennial biomass energy expansion in the United States (U.S.). Using short-term/high-resolution (1 year/1km) and climate scale/medium range resolution (10 years/20km) simulations with the Weather Research and Forecasting (WRF) system, an atmospheric code coupled to a suite of land surface models, we quantify impacts on the hydrologic cycle, and examine the effect of energy crops (e.g., miscanthus and switchgrass) on subsurface hydrology (e.g., soil moisture, groundwater impacts) and atmospheric dynamics. We avoid the competition with food crops by focusing energy crop deployment exclusively on abandoned and degraded farmland regions within the Continental U.S. Finally, assessment of photosynthetic production of bioenergy crops is made, based on hydro-climatic constraints associated with varying scenarios of perennial bioenergy crop deployment simulated with WRF.

  10. Fusarium-induced diseases of tropical, perennial crops.

    Science.gov (United States)

    Ploetz, Randy C

    2006-06-01

    ABSTRACT The world's oldest ecosystems are found in the tropics. They are diverse, highly evolved, but barely understood. This and subsequent papers describe diseases of tropical, perennial plants that are caused by Fusarium spp. Many of these are economically significant, difficult to manage, and of scientific interest. Some represent coevolved patho-systems (e.g., Panama disease, tracheomycosis of coffee, fusariosis of pineapple, and Fusarium wilt of oil palm), whereas others may be new-encounter diseases or are caused by generalist pathogens (cushion gall of cacao). New vector relationships are evident in other pathosystems (e.g., mango malformation), and two or more pathogens have been shown to cause some of the diseases (Panama disease and tracheomycosis of coffee). More work on these pathosystems is warranted as they could reveal much about the evolution of plant pathogens and the important diseases they cause.

  11. Crop rotations for increased soil carbon: perenniality as a guiding principle.

    Science.gov (United States)

    King, Alison E; Blesh, Jennifer

    2018-01-01

    More diverse crop rotations have been promoted for their potential to remediate the range of ecosystem services compromised by biologically simplified grain-based agroecosystems, including increasing soil organic carbon (SOC). We hypothesized that functional diversity offers a more predictive means of characterizing the impact of crop rotations on SOC concentrations than species diversity per se. Furthermore, we hypothesized that functional diversity can either increase or decrease SOC depending on its associated carbon (C) input to soil. We compiled a database of 27 cropping system sites and 169 cropping systems, recorded the species and functional diversity of crop rotations, SOC concentrations (g C kg/soil), nitrogen (N) fertilizer applications (kg N·ha-1 ·yr-1 ), and estimated C input to soil (Mg C·ha-1 ·yr-1 ). We categorized crop rotations into three broad categories: grain-only rotations, grain rotations with cover crops, and grain rotations with perennial crops. We divided the grain-only rotations into two sub-categories: cereal-only rotations and those that included both cereals and a legume grain. We compared changes in SOC and C input using mean effect sizes and 95% bootstrapped confidence intervals. Cover cropped and perennial cropped rotations, relative to grain-only rotations, increased C input by 42% and 23% and SOC concentrations by 6.3% and 12.5%, respectively. Within grain-only rotations, cereal + legume grain rotations decreased total C input (-16%), root C input (-12%), and SOC (-5.3%) relative to cereal-only rotations. We found no effect of species diversity on SOC within grain-only rotations. N fertilizer rates mediated the effect of functional diversity on SOC within grain-only crop rotations: at low N fertilizer rates (≤75 kg N·ha-1 ·yr-1 ), the decrease in SOC with cereal + legume grain rotations was less than at high N fertilizer rates. Our results show that increasing the functional diversity of crop rotations is more

  12. Roguing with replacement in perennial crops: conditions for successful disease management.

    Science.gov (United States)

    Sisterson, Mark S; Stenger, Drake C

    2013-02-01

    Replacement of diseased plants with healthy plants is commonly used to manage spread of plant pathogens in perennial cropping systems. This strategy has two potential benefits. First, removing infected plants may slow pathogen spread by eliminating inoculum sources. Second, replacing infected plants with uninfected plants may offset yield losses due to disease. The extent to which these benefits are realized depends on multiple factors. In this study, sensitivity analyses of two spatially explicit simulation models were used to evaluate how assumptions concerning implementation of a plant replacement program and pathogen spread interact to affect disease suppression. In conjunction, effects of assumptions concerning yield loss associated with disease and rates of plant maturity on yields were simultaneously evaluated. The first model was used to evaluate effects of plant replacement on pathogen spread and yield on a single farm, consisting of a perennial crop monoculture. The second model evaluated effects of plant replacement on pathogen spread and yield in a 100 farm crop growing region, with all farms maintaining a monoculture of the same perennial crop. Results indicated that efficient replacement of infected plants combined with a high degree of compliance among farms effectively slowed pathogen spread, resulting in replacement of few plants and high yields. In contrast, inefficient replacement of infected plants or limited compliance among farms failed to slow pathogen spread, resulting in replacement of large numbers of plants (on farms practicing replacement) with little yield benefit. Replacement of infected plants always increased yields relative to simulations without plant replacement provided that infected plants produced no useable yield. However, if infected plants produced useable yields, inefficient removal of infected plants resulted in lower yields relative to simulations without plant replacement for perennial crops with long maturation periods

  13. Comparative water use by maize, perennial crops, restored prairie, and poplar trees in the US Midwest

    Science.gov (United States)

    Hamilton, S. K.; Hussain, M. Z.; Bhardwaj, A. K.; Basso, B.; Robertson, G. P.

    2015-06-01

    Water use by plant communities across years of varying water availability indicates how terrestrial water balances will respond to climate change and variability as well as to land cover change. Perennial biofuel crops, likely grown mainly on marginal lands of limited water availability, provide an example of a potentially extensive future land cover conversion. We measured growing-season evapotranspiration (ET) based on daily changes in soil profile water contents in five perennial systems—switchgrass, miscanthus, native grasses, restored prairie, and hybrid poplar—and in annual maize (corn) in a temperate humid climate (Michigan, USA). Three study years (2010, 2011 and 2013) had normal growing-season rainfall (480-610 mm) whereas 2012 was a drought year (210 mm). Over all four years, mean (±SEM) growing-season ET for perennial systems did not greatly differ from corn (496 ± 21 mm), averaging 559 (±14), 458 (±31), 573 (±37), 519 (±30), and 492 (±58) mm for switchgrass, miscanthus, native grasses, prairie, and poplar, respectively. Differences in biomass production largely determined variation in water use efficiency (WUE). Miscanthus had the highest WUE in both normal and drought years (52-67 and 43 kg dry biomass ha-1 mm-1, respectively), followed by maize (40-59 and 29 kg ha-1 mm-1) the native grasses and prairie were lower and poplar was intermediate. That measured water use by perennial systems was similar to maize across normal and drought years contrasts with earlier modeling studies and suggests that rain-fed perennial biomass crops in this climate have little impact on landscape water balances, whether replacing rain-fed maize on arable lands or successional vegetation on marginal lands. Results also suggest that crop ET rates, and thus groundwater recharge, streamflow, and lake levels, may be less sensitive to climate change than has been assumed.

  14. A Decade of Carbon Flux Measurements with Annual and Perennial Crop Rotations on the Canadian Prairies

    Science.gov (United States)

    Amiro, B. D.; Tenuta, M.; Gao, X.; Gervais, M.

    2016-12-01

    The Fluxnet database has over 100 cropland sites, some of which have long-term (over a decade) measurements. Carbon neutrality is one goal of sustainable agriculture, although measurements over many annual cropping systems have indicated that soil carbon is often lost. Croplands are complex systems because the CO2 exchange depends on the type of crop, soil, weather, and management decisions such as planting date, nutrient fertilization and pest management strategy. Crop rotations are often used to decrease pest pressure, and can range from a simple 2-crop system, to have 4 or more crops in series. Carbon dioxide exchange has been measured using the flux-gradient technique since 2006 in agricultural systems in Manitoba, Canada. Two cropping systems are being followed: one that is a rotation of annual crops (corn, faba bean, spring wheat, rapeseed, barley, spring wheat, corn, soybean, spring wheat, soybean); and the other with a perennial phase of alfalfa/grass in years 3 to 6. Net ecosystem production ranged from a gain of 330 g C m-2 y-1 in corn to a loss of 75 g C m-2 y-1 in a poor spring-wheat crop. Over a decade, net ecosystem production for the annual cropping system was not significantly different from zero (carbon neutral), but the addition of the perennial phase increased the sink to 130 g C m-2 y-1. Once harvest removals were included, there was a net loss of carbon ranging from 77 g C m-2 y-1 in the annual system to 52 g C m-2 y-1 in the annual-perennial system; but neither of these were significantly different from zero. Termination of the perennial phase of the rotation only caused short-term increases in respiration. We conclude that both these systems were close to carbon-neutral over a decade even though they were tilled with a short growing season (90 to 130 days). We discuss the need for more datasets on agricultural systems to inform management options to increase the soil carbon sink.

  15. Modelling the perennial energy crop market: the role of spatial diffusion.

    Science.gov (United States)

    Alexander, Peter; Moran, Dominic; Rounsevell, Mark D A; Smith, Pete

    2013-11-06

    Biomass produced from energy crops, such as Miscanthus and short rotation coppice is expected to contribute to renewable energy targets, but the slower than anticipated development of the UK market implies the need for greater understanding of the factors that govern adoption. Here, we apply an agent-based model of the UK perennial energy crop market, including the contingent interaction of supply and demand, to understand the spatial and temporal dynamics of energy crop adoption. Results indicate that perennial energy crop supply will be between six and nine times lower than previously published, because of time lags in adoption arising from a spatial diffusion process. The model simulates time lags of at least 20 years, which is supported empirically by the analogue of oilseed rape adoption in the UK from the 1970s. This implies the need to account for time lags arising from spatial diffusion in evaluating land-use change, climate change (mitigation or adaptation) or the adoption of novel technologies.

  16. Modeling plant interspecific interactions from experiments with perennial crop mixtures to predict optimal combinations.

    Science.gov (United States)

    Halty, Virginia; Valdés, Matías; Tejera, Mauricio; Picasso, Valentín; Fort, Hugo

    2017-12-01

    The contribution of plant species richness to productivity and ecosystem functioning is a longstanding issue in ecology, with relevant implications for both conservation and agriculture. Both experiments and quantitative modeling are fundamental to the design of sustainable agroecosystems and the optimization of crop production. We modeled communities of perennial crop mixtures by using a generalized Lotka-Volterra model, i.e., a model such that the interspecific interactions are more general than purely competitive. We estimated model parameters -carrying capacities and interaction coefficients- from, respectively, the observed biomass of monocultures and bicultures measured in a large diversity experiment of seven perennial forage species in Iowa, United States. The sign and absolute value of the interaction coefficients showed that the biological interactions between species pairs included amensalism, competition, and parasitism (asymmetric positive-negative interaction), with various degrees of intensity. We tested the model fit by simulating the combinations of more than two species and comparing them with the polycultures experimental data. Overall, theoretical predictions are in good agreement with the experiments. Using this model, we also simulated species combinations that were not sown. From all possible mixtures (sown and not sown) we identified which are the most productive species combinations. Our results demonstrate that a combination of experiments and modeling can contribute to the design of sustainable agricultural systems in general and to the optimization of crop production in particular. © 2017 by the Ecological Society of America.

  17. A Calculation Tool for Analyzing Nitrogen Use Efficiency in Annual and Perennial Crops

    Directory of Open Access Journals (Sweden)

    Martin Weih

    2014-11-01

    Full Text Available Assessment of crop nitrogen use efficiency (NUE is important in agricultural research. Various approaches exist to analyze NUE. A recently proposed NUE concept is further developed and a calculation tool for practical use presented. A critical component in the NUE concept is the plants’ mean nitrogen (N content during the main growth period (N’. The N’ is delimited by the critical crop phenology stages initiating and terminating accelerated crop N uptake. Especially when experimental treatments and/or crop cultivars cause great variation in phenology, it is often not feasible to perform destructive plant harvests at the critical phenology stages for all treatments and cultivars, which may result in inaccurate estimates of N’ and, ultimately, the NUE components N uptake efficiency and yield-specific N efficiency. A method is proposed to accurately calculate the crop N contents at the relevant critical phenology stages even when sampling is made at other time points. The only requirements are two separate destructive plant harvests performed within the main growth period, together with the time points for the critical phenology events. The method was exemplified using data from wheat and the perennial energy crop Salix, and an electronic calculation tool for the various NUE components is provided.

  18. Water Use and Water-Use Efficiency of Three Perennial Bioenergy Grass Crops in Florida

    Directory of Open Access Journals (Sweden)

    Jerry M. Bennett

    2012-10-01

    Full Text Available Over two-thirds of human water withdrawals are estimated to be used for agricultural production, which is expected to increase as demand for renewable liquid fuels from agricultural crops intensifies. Despite the potential implications of bioenergy crop production on water resources, few data are available on water use of perennial bioenergy grass crops. Therefore, the objective of this study was to compare dry matter yield, water use, and water-use efficiency (WUE of elephantgrass, energycane, and giant reed, grown under field conditions for two growing seasons in North Central Florida. Using scaled sap flow sensor data, water use ranged from about 850 to 1150 mm during the growing season, and was generally greater for giant reed and less for elephantgrass. Despite similar or greater water use by giant reed, dry biomass yields of 35 to 40 Mg ha−1 were significantly greater for energycane and elephantgrass, resulting in greater WUE. Overall, water use by the bioenergy crops was greater than the rainfall received during the study, indicating that irrigation will be needed in the region to achieve optimal yields. Species differ in water use and WUE and species selection can play an important role with regard to potential consequences for water resources.

  19. Variation in canopy duration in the perennial biofuel crop Miscanthus reveals complex associations with yield

    Science.gov (United States)

    Robson, Paul R.H.; Farrar, Kerrie; Gay, Alan P.; Jensen, Elaine F.; Clifton-Brown, John C.; Donnison, Iain S.

    2013-01-01

    Energy crops can provide a sustainable source of power and fuels, and mitigate the negative effects of CO2 emissions associated with fossil fuel use. Miscanthus is a perennial C4 energy crop capable of producing large biomass yields whilst requiring low levels of input. Miscanthus is largely unimproved and therefore there could be significant opportunities to increase yield. Further increases in yield will improve the economics, energy balance, and carbon mitigation of the crop, as well as reducing land-take. One strategy to increase yield in Miscanthus is to maximize the light captured through an extension of canopy duration. In this study, canopy duration was compared among a diverse collection of 244 Miscanthus genotypes. Canopy duration was determined by calculating the number of days between canopy establishment and senescence. Yield was positively correlated with canopy duration. Earlier establishment and later senescence were also both separately correlated with higher yield. However, although genotypes with short canopy durations were low yielding, not all genotypes with long canopy durations were high yielding. Differences of yield between genotypes with long canopy durations were associated with variation in stem and leaf traits. Different methodologies to assess canopy duration traits were investigated, including visual assessment, image analysis, light interception, and different trait thresholds. The highest correlation coefficients were associated with later assessments of traits and the use of quantum sensors for canopy establishment. A model for trait optimization to enable yield improvement in Miscanthus and other bioenergy crops is discussed. PMID:23599277

  20. Risk assessment for herbaceous biomass crops: the case of perennial grasses

    Energy Technology Data Exchange (ETDEWEB)

    Lowenberg-DeBoer, J.; Lopez-Pereira, M.A. (Purdue Univ., West Lafayette, IN (US). Dept. of Agricultural Economics)

    1990-01-01

    The production of two perennial grasses, tall fescue and switchgrass, for biomass energy were included as alternative activities in a single-index model (SIM) of portfolio selection for an agricultural enterprise. Results indicate that, from the risk efficiency point of view, switchgrass is a good alternative and is included in a risk efficient farm enterprise, while tall fescue, due to its low expected return, is not included. The correlation of returns of the grass crops with those of the conventional activities was low or negative, suggesting that the energy crops may be good candidates for diversification. However, the high correlation between the returns on the two grass crops indicates that only one of them would be included in a risk efficient farm enterprise. The SIM regression estimates seemed sufficient to determine the risk characteristics of the new energy crops. The SIM quadratic-programming results added little additional information; thus, this stage of the analysis can be obviated without great loss of information. (author).

  1. Genotypic diversity effects on biomass production in native perennial bioenergy cropping systems.

    Science.gov (United States)

    Morris, Geoffrey P; Hu, Zhenbin; Grabowski, Paul P; Borevitz, Justin O; de Graaff, Marie-Anne; Miller, R Michael; Jastrow, Julie D

    2016-09-01

    The perennial grass species that are being developed as biomass feedstock crops harbor extensive genotypic diversity, but the effects of this diversity on biomass production are not well understood. We investigated the effects of genotypic diversity in switchgrass (Panicum virgatum) and big bluestem (Andropogon gerardii) on perennial biomass cropping systems in two experiments conducted over 2008-2014 at a 5.4-ha fertile field site in northeastern Illinois, USA. We varied levels of switchgrass and big bluestem genotypic diversity using various local and nonlocal cultivars - under low or high species diversity, with or without nitrogen inputs - and quantified establishment, biomass yield, and biomass composition. In one experiment ('agronomic trial'), we compared three switchgrass cultivars in monoculture to a switchgrass cultivar mixture and three different species mixtures, with or without N fertilization. In another experiment ('diversity gradient'), we varied diversity levels in switchgrass and big bluestem (1, 2, 4, or 6 cultivars per plot), with one or two species per plot. In both experiments, cultivar mixtures produced yields equivalent to or greater than the best cultivars. In the agronomic trial, the three switchgrass mixture showed the highest production overall, though not significantly different than best cultivar monoculture. In the diversity gradient, genotypic mixtures had one-third higher biomass production than the average monoculture, and none of the monocultures were significantly higher yielding than the average mixture. Year-to-year variation in yields was lowest in the three-cultivar switchgrass mixtures and Cave-In-Rock (the southern Illinois cultivar) and also reduced in the mixture of switchgrass and big bluestem relative to the species monocultures. The effects of genotypic diversity on biomass composition were modest relative to the differences among species and genotypes. Our findings suggest that local genotypes can be included in

  2. Comparative performance of annual and perennial energy cropping systems under different management regimes

    Energy Technology Data Exchange (ETDEWEB)

    Boehmel, Ute Constanze

    2007-07-18

    The theme of this thesis was chosen against the background of the necessary substitution of fossil fuels and the need to reduce greenhouse gas emissions. One major solution for these topics may be the energy generation from domestically produced biomass. The overall aim of this thesis was the identification of one or more efficient energy cropping systems for Central Europe. The existence of diverse production environments necessitates further diversification and the identification of several energy crops and the development of energy cropping systems suited to those diverse environments. This thesis starts with an introductory essay (chapter 1), which provides the background for renewable energy production, its features, demands and potentials, and the scientific basis of this thesis. Chapters 2 to 6 consist of five manuscripts to be published in reviewed journals (Papers I, II, IV and V) or in a multi-author book (Paper III). Subsequently, the results from all papers are discussed in a general setting (chapter 7), from which a general conclusion is formulated (chapter 8). The basis of the research formed four field experiments, which were conducted at the experimental sites Ihinger Hof, Oberer Lindenhof and Goldener Acker of the University of Hohenheim, in south-western Germany. Paper I addresses the overall objective of this thesis. Selected cropping systems for this experiment were short rotation willow, miscanthus, switchgrass, energy maize and two different crop rotation systems including winter oilseed rape, winter wheat and winter triticale with either conventional tillage or no-till. The systems were cultivated with three different nitrogen fertilizer applications. An energy balance was calculated to evaluate the biomass and energy yields of the different cropping systems. Results indicate that perennial lignocellulosic crops combine high biomass and net energy yields with low input and potential ecological impacts. Switchgrass, which produced low yields

  3. High quality reference genome of drumstick tree (Moringa oleifera Lam.), a potential perennial crop.

    Science.gov (United States)

    Tian, Yang; Zeng, Yan; Zhang, Jing; Yang, ChengGuang; Yan, Liang; Wang, XuanJun; Shi, ChongYing; Xie, Jing; Dai, TianYi; Peng, Lei; Zeng Huan, Yu; Xu, AnNi; Huang, YeWei; Zhang, JiaJin; Ma, Xiao; Dong, Yang; Hao, ShuMei; Sheng, Jun

    2015-07-01

    The drumstick tree (Moringa oleifera Lam.) is a perennial crop that has gained popularity in certain developing countries for its high-nutrition content and adaptability to arid and semi-arid environments. Here we report a high-quality draft genome sequence of M. oleifera. This assembly represents 91.78% of the estimated genome size and contains 19,465 protein-coding genes. Comparative genomic analysis between M. oleifera and related woody plant genomes helps clarify the general evolution of this species, while the identification of several species-specific gene families and positively selected genes in M. oleifera may help identify genes related to M. oleifera's high protein content, fast-growth, heat and stress tolerance. This reference genome greatly extends the basic research on M. oleifera, and may further promote applying genomics to enhanced breeding and improvement of M. oleifera.

  4. Carbon Sequestration by Perennial Energy Crops: Is the Jury Still Out?

    Science.gov (United States)

    Agostini, Francesco; Gregory, Andrew S; Richter, Goetz M

    Soil organic carbon (SOC) changes associated with land conversion to energy crops are central to the debate on bioenergy and their potential carbon neutrality. Here, the experimental evidence on SOC under perennial energy crops (PECs) is synthesised to parameterise a whole systems model and to identify uncertainties and knowledge gaps determining PECs being a sink or source of greenhouse gas (GHG). For Miscanthus and willow (Salix spp.) and their analogues (switchgrass, poplar), we examine carbon (C) allocation to above- and belowground residue inputs, turnover rates and retention in the soil. A meta-analysis showed that studies on dry matter partitioning and C inputs to soils are plentiful, whilst data on turnover are rare and rely on few isotopic C tracer studies. Comprehensive studies on SOC dynamics and GHG emissions under PECs are limited and subsoil processes and C losses through leaching remain unknown. Data showed dynamic changes of gross C inputs and SOC stocks depending on stand age. C inputs and turnover can now be specifically parameterised in whole PEC system models, whilst dependencies on soil texture, moisture and temperature remain empirical. In conclusion, the annual net SOC storage change exceeds the minimum mitigation requirement (0.25 Mg C ha-1 year-1) under herbaceous and woody perennials by far (1.14 to 1.88 and 0.63 to 0.72 Mg C ha-1 year-1, respectively). However, long-term time series of field data are needed to verify sustainable SOC enrichment, as the physical and chemical stabilities of SOC pools remain uncertain, although they are essential in defining the sustainability of C sequestration (half-life >25 years).

  5. Assessing hydroclimate impacts of a large-scale perennial biofuel crop expansion over the continental United States

    Science.gov (United States)

    Wang, M.; Wagner, M.; Miguez-Macho, G.; Mahalov, A.; Georgescu, M.

    2013-12-01

    Perennial bioenergy crops are a potential alternative energy source to fossil fuels that could increase U.S. energy independence and mitigate anthropogenic climate change. Large-scale conversion of existing lands to perennial bioenergy crops has shown the potential to decrease near-surface temperatures but could cause unintended consequences on water resources via changes in soil moisture/groundwater depletion. Spatiotemporal analysis of long-term and extreme hydrological impacts remains limited but is necessary for examination of large-scale sustainable deployment of this alternative energy pathway. Here, we quantify hydroclimatic impacts associated with perennial bioenergy crop expansion (e.g., miscanthus or switchgrass) and examine simulated effects on magnitude and frequency of extreme events (i.e. heat waves and anomalous precipitation events). We conduct 10-year (2001-2010) U.S. continental scale simulations of baseline and perennial bioenergy crop expansion (based on recent assessments of abandoned and degraded cropland over the conterminous U.S.) using WRF coupled to a land surface model (LEAF-Hydro) at 20 km resolution. Time series analysis and spatial statistical methods are applied to quantify extreme hydroclimate frequency owing to biofuels expansion, investigated through groundwater table depth, soil moisture and energy partitioning change and variability, and consequential impacts on ET, temperature, and precipitation. A further quantification of intensity, duration and persistence of extreme hydroclimate events is made based on extreme value theory. This study demonstrates a framework of feedback assessment between land use/land cover change and water resources, as well as evaluating feasibility and long-term sustainability of large-scale deployment of perennial bioenergy crops across the continental U.S.

  6. Ecosystem-service tradeoffs associated with switching from annual to perennial energy crops in riparian zones of the US Midwest.

    Directory of Open Access Journals (Sweden)

    Timothy D Meehan

    Full Text Available Integration of energy crops into agricultural landscapes could promote sustainability if they are placed in ways that foster multiple ecosystem services and mitigate ecosystem disservices from existing crops. We conducted a modeling study to investigate how replacing annual energy crops with perennial energy crops along Wisconsin waterways could affect a variety of provisioning and regulating ecosystem services. We found that a switch from continuous corn production to perennial-grass production decreased annual income provisioning by 75%, although it increased annual energy provisioning by 33%, decreased annual phosphorous loading to surface water by 29%, increased below-ground carbon sequestration by 30%, decreased annual nitrous oxide emissions by 84%, increased an index of pollinator abundance by an average of 11%, and increased an index of biocontrol potential by an average of 6%. We expressed the tradeoffs between income provisioning and other ecosystem services as benefit-cost ratios. Benefit-cost ratios averaged 12.06 GJ of additional net energy, 0.84 kg of avoided phosphorus pollution, 18.97 Mg of sequestered carbon, and 1.99 kg of avoided nitrous oxide emissions for every $1,000 reduction in income. These ratios varied spatially, from 2- to 70-fold depending on the ecosystem service. Benefit-cost ratios for different ecosystem services were generally correlated within watersheds, suggesting the presence of hotspots--watersheds where increases in multiple ecosystem services would come at lower-than-average opportunity costs. When assessing the monetary value of ecosystem services relative to existing conservation programs and environmental markets, the overall value of enhanced services associated with adoption of perennial energy crops was far lower than the opportunity cost. However, when we monitized services using estimates for the social costs of pollution, the value of enhanced services far exceeded the opportunity cost. This

  7. Ecosystem-service tradeoffs associated with switching from annual to perennial energy crops in riparian zones of the US Midwest.

    Science.gov (United States)

    Meehan, Timothy D; Gratton, Claudio; Diehl, Erica; Hunt, Natalie D; Mooney, Daniel F; Ventura, Stephen J; Barham, Bradford L; Jackson, Randall D

    2013-01-01

    Integration of energy crops into agricultural landscapes could promote sustainability if they are placed in ways that foster multiple ecosystem services and mitigate ecosystem disservices from existing crops. We conducted a modeling study to investigate how replacing annual energy crops with perennial energy crops along Wisconsin waterways could affect a variety of provisioning and regulating ecosystem services. We found that a switch from continuous corn production to perennial-grass production decreased annual income provisioning by 75%, although it increased annual energy provisioning by 33%, decreased annual phosphorous loading to surface water by 29%, increased below-ground carbon sequestration by 30%, decreased annual nitrous oxide emissions by 84%, increased an index of pollinator abundance by an average of 11%, and increased an index of biocontrol potential by an average of 6%. We expressed the tradeoffs between income provisioning and other ecosystem services as benefit-cost ratios. Benefit-cost ratios averaged 12.06 GJ of additional net energy, 0.84 kg of avoided phosphorus pollution, 18.97 Mg of sequestered carbon, and 1.99 kg of avoided nitrous oxide emissions for every $1,000 reduction in income. These ratios varied spatially, from 2- to 70-fold depending on the ecosystem service. Benefit-cost ratios for different ecosystem services were generally correlated within watersheds, suggesting the presence of hotspots--watersheds where increases in multiple ecosystem services would come at lower-than-average opportunity costs. When assessing the monetary value of ecosystem services relative to existing conservation programs and environmental markets, the overall value of enhanced services associated with adoption of perennial energy crops was far lower than the opportunity cost. However, when we monitized services using estimates for the social costs of pollution, the value of enhanced services far exceeded the opportunity cost. This disparity between

  8. The development and current status of perennial rhizomatous grasses as energy crops in the US and Europe

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowski, I. [Universiteit Utrecht (Netherlands). Copernicus Institute for Sustainable Development and Innovation, Department of Science, Technology and Society; Scurlock, J.M.O. [Oak Ridge National Laboratory, TN (United States). Environmental Sciences Division; Lindvall, E. [Svaloef Weibull AB, Umeae (Sweden); Christou, M. [Center for Renewable Energy Sources, Pikermi-Attikis (Greece)

    2003-10-01

    Perennial grasses display many beneficial attributes as energy crops, and there has been increasing interest in their use in the US and Europe since the mid-1980s. In the US, the Herbaceous Energy Crops Research Program (HECP), funded by the US Department of Energy (DOE), was established in 1984. After evaluating 35 potential herbaceous crops of which 18 were perennial grasses it was concluded that switchgrass (Panicum virgatum) was the native perennial grass which showed the greatest potential. In 1991, the DOE's Bioenergy Feedstock Development Program (BFDP), which evolved from the HECP, decided to focus research on a 'model' crop system and to concentrate research resources on switchgrass, in order to rapidly attain its maximal output as a biomass crop. In Europe, about 20 perennial grasses have been tested and four perennial rhizomatous grasses (PRG), namely miscanthus (Miscanthus spp.), reed canarygrass (Phalaris arundinacea) giant reed (Arundo donax) and switchgrass (Panicum virgatum) were chosen for more extensive research programs. Reed canary grass and giant reed are grasses with the C{sub 3} photosynthetic pathway, and are native to Europe. Miscanthus, which originated in Southeast Asia, and switchgrass, native to North America, are both C{sub 4} grasses. These four grasses differ in their ecological/climatic demands, their yield potentials, biomass characteristics and crop management requirements. Efficient production of bioenergy from such perennial grasses requires the choice of the most appropriate grass species for the given ecological/climatic conditions. In temperate and warm regions, C{sub 4} grasses outyield C{sub 3} grasses due to their more efficient photosynthetic pathway. However, the further north perennial grasses are planted, the more likely cool season grasses are to yield more than warm season grasses. Low winter temperatures and short vegetation periods are major limits to the growth of C{sub 4} grasses in northern Europe

  9. Genomic selection prediction accuracy in a perennial crop: case study of oil palm (Elaeis guineensis Jacq.).

    Science.gov (United States)

    Cros, David; Denis, Marie; Sánchez, Leopoldo; Cochard, Benoit; Flori, Albert; Durand-Gasselin, Tristan; Nouy, Bruno; Omoré, Alphonse; Pomiès, Virginie; Riou, Virginie; Suryana, Edyana; Bouvet, Jean-Marc

    2015-03-01

    Genomic selection empirically appeared valuable for reciprocal recurrent selection in oil palm as it could account for family effects and Mendelian sampling terms, despite small populations and low marker density. Genomic selection (GS) can increase the genetic gain in plants. In perennial crops, this is expected mainly through shortened breeding cycles and increased selection intensity, which requires sufficient GS accuracy in selection candidates, despite often small training populations. Our objective was to obtain the first empirical estimate of GS accuracy in oil palm (Elaeis guineensis), the major world oil crop. We used two parental populations involved in conventional reciprocal recurrent selection (Deli and Group B) with 131 individuals each, genotyped with 265 SSR. We estimated within-population GS accuracies when predicting breeding values of non-progeny-tested individuals for eight yield traits. We used three methods to sample training sets and five statistical methods to estimate genomic breeding values. The results showed that GS could account for family effects and Mendelian sampling terms in Group B but only for family effects in Deli. Presumably, this difference between populations originated from their contrasting breeding history. The GS accuracy ranged from -0.41 to 0.94 and was positively correlated with the relationship between training and test sets. Training sets optimized with the so-called CDmean criterion gave the highest accuracies, ranging from 0.49 (pulp to fruit ratio in Group B) to 0.94 (fruit weight in Group B). The statistical methods did not affect the accuracy. Finally, Group B could be preselected for progeny tests by applying GS to key yield traits, therefore increasing the selection intensity. Our results should be valuable for breeding programs with small populations, long breeding cycles, or reduced effective size.

  10. Soil Compressibility under Irrigated Perennial and Annual Crops in a Semi-Arid Environment

    Directory of Open Access Journals (Sweden)

    Rafaela Watanabe

    Full Text Available ABSTRACT In irrigated soils, a continuous state of high moisture reduces resistance of the soil to applied external forces, favouring compaction. The aim of this study was to evaluate the susceptibility to compaction of developed calcareous soils in irrigated annual and perennial cropping systems of the Apodi Plateau, located in the Brazilian semi-arid region. Four areas of irrigated crops were evaluated: banana after two (B2 and 15 (B15 years cultivation, pasture (P, and a corn and beans succession (MB, as well as the reference areas for soil quality and corresponding natural vegetation (NVB2, NVB15, NVP and NVMB. Samples were collected at layers of 0.00-0.10 and 0.20-0.30 m; and for B2 and B15, samples were collected in the row and inter-row spaces. The following properties were determined: degree of compactness (DC, preconsolidation pressure (σp, compression index (Cc, maximum density (ρmax, critical water content (WCcrit, total organic carbon (TOC and carbon of light organic matter (Clom. Mean values were compared by the t-test at 5, 10, 15 and 20 % probability. An increase was seen in DC at a layer of 0.20-0.30 m in MB (p<0.15, showing the deleterious effects of preparing the soil by ploughing and chiselling, together with the cumulative traffic of heavy machinery. The TOC had a greater influence on ρmax than the stocks of Clom. Irrigation caused a reduction in Cc, and there was no effect on σp at field capacity. The planting rows showed different behaviour for Cc, ρmax, and WCcrit,, and in general the physical properties displayed better conditions than the inter-row spaces. Values for σp and Cc showed that agricultural soils display greater load-bearing capacity and are less susceptible to compaction in relation to soils under natural vegetation.

  11. Direct climate effects of perennial bioenergy crops in the United States.

    Science.gov (United States)

    Georgescu, Matei; Lobell, David B; Field, Christopher B

    2011-03-15

    Biomass-derived energy offers the potential to increase energy security while mitigating anthropogenic climate change, but a successful path toward increased production requires a thorough accounting of costs and benefits. Until recently, the efficacy of biomass-derived energy has focused primarily on biogeochemical consequences. Here we show that the biogeophysical effects that result from hypothetical conversion of annual to perennial bioenergy crops across the central United States impart a significant local to regional cooling with considerable implications for the reservoir of stored soil water. This cooling effect is related mainly to local increases in transpiration, but also to higher albedo. The reduction in radiative forcing from albedo alone is equivalent to a carbon emissions reduction of , which is six times larger than the annual biogeochemical effects that arise from offsetting fossil fuel use. Thus, in the near-term, the biogeophysical effects are an important aspect of climate impacts of biofuels, even at the global scale. Locally, the simulated cooling is sufficiently large to partially offset projected warming due to increasing greenhouse gases over the next few decades. These results demonstrate that a thorough evaluation of costs and benefits of bioenergy-related land-use change must include potential impacts on the surface energy and water balance to comprehensively address important concerns for local, regional, and global climate change.

  12. Sustainable domestic effluent reuse via Subsurface Drip Irrigation (SDI): alfalfa as a perennial model crop.

    Science.gov (United States)

    Kazumba, Shija; Gillerman, Leonid; DeMalach, Yoel; Oron, Gideon

    2010-01-01

    Scarcity of fresh high-quality water has heightened the importance of wastewater reuse primarily in dry regions together with improving its efficient use by implementing the Subsurface Drip Irrigation (SDI) method. Sustainable effluent reuse combines soil and plant aspects, along with the maintainability of the application system. In this study, field experiments were conducted for two years on the commercial farm of Revivim and Mashabay-Sade farm (RMF) southeast of the City of Beer-Sheva, Israel. The purpose was to examine the response of alfalfa (Medicago sativa) as a perennial model crop to secondary domestic effluent application by means of a SDI system as compared with conventional overhead sprinkler irrigation. Emitters were installed at different depths and spacing. Similar amounts of effluent were applied to all plots during the experimental period. The results indicated that in all SDI treatments, the alfalfa yields were 11% to 25% higher than the ones obtained under sprinkler irrigated plots, besides the one in which the drip laterals were 200 cm apart. The average Water Use Efficiency (WUE) was better in all SDI treatments in comparison with the sprinkler irrigated plots. An economic assessment reveals the dependence of the net profit on the emitters' installation geometry, combined with the return for alfalfa in the market.

  13. Comparative population genomics reveals the domestication history of the peach, Prunus persica, and human influences on perennial fruit crops.

    Science.gov (United States)

    Cao, Ke; Zheng, Zhijun; Wang, Lirong; Liu, Xin; Zhu, Gengrui; Fang, Weichao; Cheng, Shifeng; Zeng, Peng; Chen, Changwen; Wang, Xinwei; Xie, Min; Zhong, Xiao; Wang, Xiaoli; Zhao, Pei; Bian, Chao; Zhu, Yinling; Zhang, Jiahui; Ma, Guosheng; Chen, Chengxuan; Li, Yanjun; Hao, Fengge; Li, Yong; Huang, Guodong; Li, Yuxiang; Li, Haiyan; Guo, Jian; Xu, Xun; Wang, Jun

    2014-07-31

    Recently, many studies utilizing next generation sequencing have investigated plant evolution and domestication in annual crops. Peach, Prunus persica, is a typical perennial fruit crop that has ornamental and edible varieties. Unlike other fruit crops, cultivated peach includes a large number of phenotypes but few polymorphisms. In this study, we explore the genetic basis of domestication in peach and the influence of humans on its evolution. We perform large-scale resequencing of 10 wild and 74 cultivated peach varieties, including 9 ornamental, 23 breeding, and 42 landrace lines. We identify 4.6 million SNPs, a large number of which could explain the phenotypic variation in cultivated peach. Population analysis shows a single domestication event, the speciation of P. persica from wild peach. Ornamental and edible peach both belong to P. persica, along with another geographically separated subgroup, Prunus ferganensis. Our analyses enhance our knowledge of the domestication history of perennial fruit crops, and the dataset we generated could be useful for future research on comparative population genomics.

  14. Bioestadística en cultivos Perennes Biostatistics in Perennial crops

    Directory of Open Access Journals (Sweden)

    Martínez B. Ricardo

    1989-12-01

    varios períodos de tiempo sobre las mismas plantas. El análisis estadístico debe tener en cuenta esto y por lo tanto se sugieren algunos métodos de trabajo.Perennial crops live longer than annual crops, and since they are likely to be larger, experiments with them face special problems. The experiments often taken several years, so the plants are at risk longer, increasing the likelihood of mishap and thus unbalanced data, so greater caution is needed in making plants about them. The experimental design must be able to tolerate the inevitable missing data. Whatever design is used, it must be throughly practicable, for it is no use producing a scheme on paper that will give endless trouble in the field. Experimental objetives may change over time, requiring modification of the original study plan. It is better simple experimental design than complex ones, these are inflexible and are seriously undermined by missing data in both computation and interpretation. Since perennials are in general larger than annuals are of greater interest as individuals, and will probably use single.plant or several
    plant plots, and environmental variation in rarely of sole importance. With perennials the experimenter should not assume de error variation as positional, Le envirenmental,
    some of it may well derive from the plants themselves.
    Attempting to reduce error variance by merely increasing replicationwithin a standar design may not be satisfactory, The analysis of covariance has proven to be very effective
    alternative in many cases, after reducing de error variance by 25.50%. The data will probably include several observations collected over time on the same plant. The statistical analysis must take this into account, and several possible methods
    are suggested.

  15. Effects of strip intercropping concept with perennial diversified grass-clover strip and annual winter rye-winter vetch intercrop as energy crops

    OpenAIRE

    Hauggaard-Nielsen, Henrik; Johansen , Anders; Carter, Mette S.; Ambus, Per; Jensen, Erik Steen

    2011-01-01

    The combination of perennials and annuals in a strip cropping system is challenging primarily because the interspecific competitive ability of the perennials towards the annuals seems to be too dominating. Especially at the first harvest (tillering) closest to the adjacent grass-clover strip severe total dry matter production reductions was found ranging from 25%, 5% and 20% in the vetch SC, rye SC and vetch-rye IC, respectively. Rye in particular was suffering from the grass-clover interspec...

  16. Plant growth regulation in seed crops of perennial ryegrass (Lolium perenne L)

    DEFF Research Database (Denmark)

    Boelt, Birte; Lemaire, Charles; Abel, Simon

    2016-01-01

    Seed yield components were recorded in plants of perennial ryegrass cv. Calibra a medium late, forage type (4n) in a two factorial block design with Nitrogen (N) and plant growth regulator (PGR) application in 2014 and 2015 at Aarhus University (AU), Flakkebjerg. For each plant, reproductive...

  17. Implications for water use of a shift from annual to perennial crops - A stochastic modelling approach based on a trait meta-analysis

    Science.gov (United States)

    Vico, Giulia; Brunsell, Nathaniel

    2017-04-01

    The projected population growth and changes in climate and dietary habits will further increase the pressure on water resources globally. Within precision farming, a host of technical solutions has been developed to reduce water consumption for agricultural uses. The next frontier for a more sustainable agriculture is the combination of reduced water requirements with enhanced ecosystem services. Currently, staple grains are obtained from annuals crops. A shift from annual to perennial crops has been suggested as a way to enhance ecosystem services. In fact, perennial plants, with their continuous soil cover and the higher allocation of resources to the below ground, contribute to the reduction of soil erosion and nutrient losses, while enhancing carbon sequestration in the root zone. Nevertheless, the net effect of a shift to perennial crops on water use for agriculture is still unknown, despite its relevance for the sustainability of such a shift. We explore here the implications for water management at the field- to farm-scale of a shift from annual to perennial crops, under rainfed and irrigated agriculture. A probabilistic description of the soil water balance and crop development is employed to quantify water requirements and yields and their inter-annual variability, as a function of rainfall patterns, soil and crop features. Optimal irrigation strategies are thus defined in terms of maximization of yield and minimization of required irrigation volumes and their inter-annual variability. The probabilistic model is parameterized based on an extensive meta-analysis of traits of co-generic annual and perennial species to explore the consequences for water requirements of shifting from annual to perennial crops under current and future climates. We show that the larger and more developed roots of perennial crops may allow a better exploitation of soil water resources and a reduction of yield variability with respect to annual species. At the same time, perennial

  18. A Calculation Tool for Analyzing Nitrogen Use Efficiency in Annual and Perennial Crops

    OpenAIRE

    Martin Weih

    2014-01-01

    Assessment of crop nitrogen use efficiency (NUE) is important in agricultural research. Various approaches exist to analyze NUE. A recently proposed NUE concept is further developed and a calculation tool for practical use presented. A critical component in the NUE concept is the plants’ mean nitrogen (N) content during the main growth period (N’). The N’ is delimited by the critical crop phenology stages initiating and terminating accelerated crop N uptake. Especially when experimental treat...

  19. Comparing annual and perennial crops for bioenergy production - influence on nitrate leaching and energy balance

    DEFF Research Database (Denmark)

    Pugesgaard, Siri; Schelde, Kirsten; Ugilt Larsen, Søren

    2015-01-01

    Production of energy crops is promoted as a means to mitigate global warming by decreasing dependency on fossil energy. However, agricultural production of bioenergy can have various environmental effects depending on the crop and production system. In a field trial initiated in 2008, nitrate...

  20. Ownership characteristics and crop selection in California cropland

    Directory of Open Access Journals (Sweden)

    Luke Macaulay

    2017-11-01

    Full Text Available Land ownership is one of the primary determinants of how agricultural land is used, and property size has been shown to drive many land use decisions. Land ownership information is also key to understanding food production systems and land fragmentation, and in targeting outreach materials to improve agricultural production and conservation practices. Using a parcel dataset containing all 58 California counties, we describe the characteristics of cropland ownership across California. The largest 5% of properties — with “property” defined as all parcels owned by a given landowner — account for 50.6% of California cropland, while the smallest 84% of properties account for 25% of cropland. Cropland ownership inequality (few large properties, many small properties was greatest in Kings, Kern and Contra Costa counties and lowest in Mendocino, Napa and Santa Clara counties. Of crop types, rice properties had the largest median size, while properties with orchard trees had the smallest median sizes. Cluster analysis of crop mixes revealed that properties with grapes, rice, almonds and alfalfa/hay tended to be planted to individual crops, while crops such as grains, tomatoes and vegetables were more likely to be mixed within a single property. Analyses of cropland ownership patterns can help researchers prioritize outreach efforts and tailor research to stakeholders' needs.

  1. Multi-farm economic analysis of perennial energy crops in Central Greece, taking into account the CAP reform

    Energy Technology Data Exchange (ETDEWEB)

    Lychnaras, Vassilis [Centre for Planning and Economic Research, 11, Amerikis str., 106 72 Athens (Greece); Schneider, Uwe A. [Research Unit Sustainability and Global Change, University of Hamburg, KlimaCampus Hamburg, Bundesstrasse 55, D-20146 Hamburg (Germany)

    2011-01-15

    This study analyses farm level economic impacts of biomass production from perennial crops including Arundo donax L. (arundo), Miscanthus x giganteus (miscanthus), Panicum virgatum L. (switchgrass) and Cynara cardunculus L. (cardoon). Regional biomass supply curves are estimated with a dynamic, multi-farm, mathematical programming model. Micro-economic data for the model are generated from farm surveys covering 52 farms containing a total of 400 parcels, in Central Greece. The study also examines the potential effects of the Common Agricultural Policy reform in 2003 on regional biomass supply. Simulations show that the policy reform toward decoupled subsidies lowers the cost of biomass between 15 and 25 euro per tonne. Switchgrass appears to be the most attractive option, followed by cardoon and miscanthus. Due to high specific machinery cost, arundo is never preferred. Relative to the agricultural policy setting of Agenda 2000, the biomass potential increases more for farms of small economic size and farms with a higher share of cotton. (author)

  2. Bioenergy production from perennial energy crops: A consequential LCA of 12 bioenergy scenarios including land use changes

    DEFF Research Database (Denmark)

    Tonini, Davide; Hamelin, Lorie; Wenzel, Henrik

    2012-01-01

    In the endeavor of optimizing the sustainability of bioenergy production in Denmark, this consequential life cycle assessment (LCA) evaluated the environmental impacts associated with the production of heat and electricity from one hectare of Danish arable land cultivated with three perennial crops......: ryegrass (Lolium perenne), willow (Salix viminalis) and Miscanthus giganteus. For each, four conversion pathways were assessed against a fossil fuel reference: (I) anaerobic co-digestion with manure, (II) gasification, (III) combustion in small-to-medium scale biomass combined heat and power (CHP) plants...... and IV) co-firing in large scale coal-fired CHP plants. Soil carbon changes, direct and indirect land use changes as well as uncertainty analysis (sensitivity, MonteCarlo) were included in the LCA. Results showed that global warming was the bottleneck impact, where only two scenarios, namely willow...

  3. Satellite Estimation of Fractional Cover in Several California Specialty Crops

    Science.gov (United States)

    Johnson, Lee; Cahn, Michael; Rosevelt, Carolyn; Guzman, Alberto; Farrara, Barry; Melton, Forrest S.

    2016-01-01

    Past research in California and elsewhere has revealed strong relationships between satellite NDVI, photosynthetically active vegetation fraction (Fc), and crop evapotranspiration (ETc). Estimation of ETc can support efficiency of irrigation practice, which enhances water security and may mitigate nitrate leaching. The U.C. Cooperative Extension previously developed the CropManage (CM) web application for evaluation of crop water requirement and irrigation scheduling for several high-value specialty crops. CM currently uses empirical equations to predict daily Fc as a function of crop type, planting date and expected harvest date. The Fc prediction is transformed to fraction of reference ET and combined with reference data from the California Irrigation Management Information System to estimate daily ETc. In the current study, atmospherically-corrected Landsat NDVI data were compared with in-situ Fc estimates on several crops in the Salinas Valley during 2011-2014. The satellite data were observed on day of ground collection or were linearly interpolated across no more than an 8-day revisit period. Results will be presented for lettuce, spinach, celery, broccoli, cauliflower, cabbage, peppers, and strawberry. An application programming interface (API) allows CM and other clients to automatically retrieve NDVI and associated data from NASA's Satellite Irrigation Management Support (SIMS) web service. The SIMS API allows for queries both by individual points or user-defined polygons, and provides data for individual days or annual timeseries. Updates to the CM web app will convert these NDVI data to Fc on a crop-specific basis. The satellite observations are expected to play a support role in Salinas Valley, and may eventually serve as a primary data source as CM is extended to crop systems or regions where Fc is less predictable.

  4. Testing an Irrigation Decision Support Tool for California Specialty Crops

    Science.gov (United States)

    Johnson, L.; Cahn, M.; Benzen, S.; Zaragoza, I.; Murphy, L.; Melton, F. S.; Martin, F.; Quackenbush, A.; Lockhart, T.

    2015-12-01

    Estimation of crop evapotranspiration supports efficiency of irrigation water management, which in turn can mitigate nitrate leaching, groundwater depletion, and provide energy savings. Past research in California and elsewhere has revealed strong relationships between photosynthetically active vegetation fraction (Fc) and crop evapotranspiration (ETc). Additional research has shown the potential of monitoring Fc by satellite remote sensing. The U.C. Cooperative Extension developed and operates CropManage (CM) as on-line database irrigation (and nitrogen) scheduling tool. CM accounts for the rapid growth and typically brief cycle of cool-season vegetables, where Fc and fraction of reference ET can change daily during canopy development. The model automates crop water requirement calculations based on reference ET data collected by California Dept. Water Resources. Empirically-derived equations are used to estimate daily Fc time-series for a given crop type primarily as a function of planting date and expected harvest date. An application programming interface (API) is under development to provide a check on modeled Fc of current crops and facilitate CM expansion to new crops. The API will enable CM to extract field scale Fc observations from NASA's Satellite Irrigation Management Support (SIMS). SIMS is mainly Landsat based and currently monitors Fc over about 8 million irrigation acres statewide, with potential for adding data from ESA/Sentinel for improved temporal resolution. In the current study, a replicated irrigation trial was performed on romaine lettuce at the USDA Agricultural Research Station in Salinas, CA. CropManage recommendations were used to guide water treatments by drip irrigation at 50%, 75%, 100% ETc replacement levels, with an added treatment at 150% ET representing grower standard practice. Experimental results indicate that yields from the 100% and 150% treatments were not significantly different and were in-line with industry average, while

  5. Satellite Estimation of Fractional Cover in Several California Specialty Crops

    Science.gov (United States)

    Johnson, L.; Cahn, M.; Rosevelt, C.; Guzman, A.; Lockhart, T.; Farrara, B.; Melton, F. S.

    2016-12-01

    Past research in California and elsewhere has revealed strong relationships between satellite NDVI, photosynthetically active vegetation fraction (Fc), and crop evapotranspiration (ETc). Estimation of ETc can support efficiency of irrigation practice, which enhances water security and may mitigate nitrate leaching. The U.C. Cooperative Extension previously developed the CropManage (CM) web application for evaluation of crop water requirement and irrigation scheduling for several high-value specialty crops. CM currently uses empirical equations to predict daily Fc as a function of crop type, planting date and expected harvest date. The Fc prediction is transformed to fraction of reference ET and combined with reference data from the California Irrigation Management Information System to estimate daily ETc. In the current study, atmospherically-corrected Landsat NDVI data were compared with in-situ Fc estimates on several crops in the Salinas Valley during 2011-2014. The satellite data were observed on day of ground collection or were linearly interpolated across no more than an 8-day revisit period. Results will be presented for lettuce, spinach, celery, broccoli, cauliflower, cabbage, peppers, and strawberry. An application programming interface (API) allows CM and other clients to automatically retrieve NDVI and associated data from NASA's Satellite Irrigation Management Support (SIMS) web service. The SIMS API allows for queries both by individual points or user-defined polygons, and provides data for individual days or annual timeseries. Updates to the CM web app will convert these NDVI data to Fc on a crop-specific basis. The satellite observations are expected to play a support role in Salinas Valley, and may eventually serve as a primary data source as CM is extended to crop systems or regions where Fc is less predictable.

  6. Strip cropping of alternating perennial grass–clover and annual rye–vetch intercrops when grown within an organic farming system

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Johansen, A.; Carter, Mette Sustmann

    2012-01-01

    interactions. Less soil water content below the perennial strip indicated greater water uptake, than below the annual strips. Unfortunately, the present strip cropping system did not possess the right balance of co-existence and complementarity. However, from a practical point of view the system was manageable...

  7. Annual maize and perennial grass-clover strip cropping for increased resource use efficiency and productivity using organic farming practice as a model

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Johansen, Anders; Carter, Mette Sustmann

    2013-01-01

    A cropping system was designed to fulfill the increasing demand for biomass for food and energy without decreasing long term soil fertility. A field experiment was carried out including alternating strips of annual maize (Zea mays L.) and perennial ryegrass (Lolium perenne L.) – clover (Trifolium...

  8. Direct control of perennial weeds between crops - Implication for organic farming

    DEFF Research Database (Denmark)

    Melander, Bo; Holst, Niels; Rasmussen, Ilse Ankjær

    2012-01-01

    season that followed the post-harvest treatments. In the one experiment, repeated tine cultivation caused an 80–90% annual reduction of the population of mainly Cirsium arvense. With treatments conducted in two consecutive years, the accumulated effects reached 99% control. In the second experiment...... and ending the strategy with mouldboard ploughing in the succeeding spring. Grain yields did not differ among the treatments in the two experiments as a result of the generally high effectiveness exerted by the control strategies. Especially post-harvest control strategies based on rotating weed devices...... of different implement types and strategies. The treatments were employed against mixed stands of perennials after harvest of spring barley in two consecutive years. Time of treatment, cultivation depth and combinations of implements constituted the strategies. Treatment effects were evaluated in the growing...

  9. C4 bioenergy crops for cool climates, with special emphasis on perennial C4 grasses.

    Science.gov (United States)

    Sage, Rowan F; de Melo Peixoto, Murilo; Friesen, Patrick; Deen, Bill

    2015-07-01

    There is much interest in cultivating C4 perennial plants in northern climates where there is an abundance of land and a potential large market for biofuels. C4 feedstocks can exhibit superior yields to C3 alternatives during the long warm days of summer at high latitude, but their summer success depends on an ability to tolerate deep winter cold, spring frosts, and early growth-season chill. Here, we review cold tolerance limits in C4 perennial grasses. Dozens of C4 species are known from high latitudes to 63 °N and elevations up to 5200 m, demonstrating that C4 plants can adapt to cold climates. Of the three leading C4 grasses being considered for bioenergy production in cold climates--Miscanthus spp., switchgrass (Panicum virgatum), and prairie cordgrass (Spartina pectinata)--all are tolerant of cool temperatures (10-15 °C), but only cordgrass tolerates hard spring frosts. All three species overwinter as dormant rhizomes. In the productive Miscanthus×giganteus hybrids, exposure to temperatures below -3 °C to -7 °C will kill overwintering rhizomes, while for upland switchgrass and cordgrass, rhizomes survive exposure to temperatures above -20 °C to -24 °C. Cordgrass emerges earlier than switchgrass and M. giganteus genotypes, but lacks the Miscanthus growth potential once warmer days of late spring arrive. To enable C4-based bioenergy production in colder climates, breeding priorities should emphasize improved cold tolerance of M.×giganteus, and enhanced productivity of switchgrass and cordgrass. This should be feasible in the near future, because wild populations of each species exhibit a diverse range of cold tolerance and growth capabilities. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. Carbon dioxide flux as affected by tillage and irrigation in soil converted from perennial forages to annual crops.

    Science.gov (United States)

    Jabro, J D; Sainju, U; Stevens, W B; Evans, R G

    2008-09-01

    Among greenhouse gases, carbon dioxide (CO(2)) is one of the most significant contributors to regional and global warming as well as climatic change. A field study was conducted to (i) determine the effect of soil characteristics resulting from changes in soil management practices on CO(2) flux from the soil surface to the atmosphere in transitional land from perennial forages to annual crops, and (ii) develop empirical relationships that predict CO(2) flux from soil temperature and soil water content. The CO(2) flux, soil temperature (T(s)), volumetric soil water content (theta(v)) were measured every 1-2 weeks in no-till (NT) and conventional till (CT) malt barley and undisturbed soil grass-alfalfa (UGA) systems in a Lihen sandy loam soil (sandy, mixed, frigid Entic Haplustoll) under irrigated and non-irrigated conditions in western North Dakota. Soil air-filled porosity (epsilon) was calculated from total soil porosity and theta(v) measurements. Significant differences in CO(2) fluxes between land management practices (irrigation and tillage) were observed on some measurement dates. Higher CO(2) fluxes were detected in CT plots than in NT and UGA treatments immediately after rainfall or irrigation. Soil CO(2) fluxes increased with increasing soil moisture (R(2)=0.15, Pforages to annual crops.

  11. Genomic approaches to selection in outcrossing perennials: focus on essential oil crops.

    Science.gov (United States)

    Kainer, David; Lanfear, Robert; Foley, William J; Külheim, Carsten

    2015-12-01

    The yield of essential oil in commercially harvested perennial species (e.g. 'Oil Mallee' eucalypts, Tea Trees and Hop) is dependent on complex quantitative traits such as foliar oil concentration, biomass and adaptability. These often show large natural variation and some are highly heritable, which has enabled significant gains in oil yield via traditional phenotypic recurrent selection. Analysis of transcript abundance and allelic diversity has revealed that essential oil yield is likely to be controlled by large numbers of quantitative trait loci that range from a few of medium/large effect to many of small effect. Molecular breeding techniques that exploit this information could increase gains per unit time and address complications of traditional breeding such as genetic correlations between key traits and the lower heritability of biomass. Genomic selection (GS) is a technique that uses the information from markers genotyped across the whole genome in order to predict the phenotype of progeny well before they reach maturity, allowing selection at an earlier age. In this review, we investigate the feasibility of genomic selection (GS) for the improvement of essential oil yield. We explore the challenges facing breeders selecting for oil yield, and how GS might deal with them. We then assess the factors that affect the accuracy of genomic estimated breeding values, such as linkage disequilibrium (LD), heritability, relatedness and the genetic architecture of desirable traits. We conclude that GS has the potential to significantly improve the efficiency of selection for essential oil yield.

  12. Greenhouse Gas Emissions Increase Following the Termination of a Perennial Legume Phase of an Annual Crop Rotation within the Red River Valley, Manitoba

    Science.gov (United States)

    Hanis, K. L.; Tenuta, M.; Amiro, B. D.; Glenn, A. J.; Maas, S.; Gervais, M.

    2013-12-01

    Perennial legume forages may have the potential to increase soil carbon sequestration and decrease nitrous oxide (N2O) emissions to the atmosphere when introduced into annual cropping systems. However, little is known about what short-term effect the return to annual cropping following termination of perennial legume forage would have on carbon dioxide (CO2) and N2O emissions. Furthermore, there are few quantitative measurements about this impact on the Canadian Prairies. A long-term field experiment to continuously measure CO2 and N2O fluxes was established at the Trace Gas Manitoba (TGAS-MAN) Long Term Greenhouse Gas Monitoring Site at Glenlea, Manitoba using the flux gradient micrometeorlogical technique with a tunable diode laser analyzer. The soil is poorly drained clay in the Red River Valley. The field experiment consisted of four 4-hectare plots planted to corn in 2006 and faba bean in 2007. In 2008, grass-alfalfa forage was introduced to two plots (annual - perennial) and grown until 2011 whereas the other two plots (annual) were planted to annual crops: spring wheat, rapeseed, barley and spring wheat in 2008, 2009, 2010 and 2011, respectively. In late September of 2011 the grass-alfalfa forage was killed and in 2012 all four plots were planted with corn. Termination of the grass-alfalfa forage resulted in greater fall CO2 emissions in 2011, greater spring melt CO2 emissions and net annual N2O emissions in 2012 from the annual-perennial plots when compared to the annual plots. Over seven crop years (2006-2012), the annual - perennial system increased carbon uptake by 3.4 Mg C ha-1 and reduced N2O emissions by 3.0 Mg CO2-eq ha-1 compared to the annual system. However after accounting for harvest removals both the annual and annual-perennial systems were net carbon sources of 5.7 and 2.5 Mg C ha-1 and net GHG sources of 38 and 24 Mg CO2-eq ha-1 respectively. We are currently following the long-term impacts of inclusion of perennial forages in an annual

  13. Abundance and Diversity of Soil Macrofauna in Native Forest, Eucalyptus Plantations, Perennial Pasture, Integrated Crop-Livestock, and No-Tillage Cropping

    Directory of Open Access Journals (Sweden)

    Sheila Trierveiler de Souza

    2016-01-01

    Full Text Available ABSTRACT Intensive land use can affect macrofaunal biodiversity, which is a property that can be used as a soil quality indicator. This study evaluated the abundance and diversity of soil macrofauna and its relation to soil chemical and physical properties in five land use systems (LUS in the eastern region of Santa Catarina. The following LUS were studied: native forest (NF, eucalyptus plantations (EP, perennial pasture (PP, integrated crop-livestock (ICL, and no-tillage cropping (NT. The macrofauna was quantified in 0.25 × 0.25 m monoliths and sampled in the 0.00-0.20 m layer in the summer (Jan/2012 and winter (Jul/2012. For each LUS, nine points were sampled, distributed in a 30 × 30 m sampling grid. After screening the edaphic macrofauna organisms, the individuals were counted and identified at the species level when possible, or in major taxonomic groups. The Shannon diversity indices were calculated and the macrofaunal groups together with the physical and chemical properties were subjected to principal component (PCA and redundancy analysis (RDA. The abundance and diversity of macrofaunal groups are affected by the LUS. The properties of organic matter, macroporosity, bulk density, cation exchange capacity at pH 7.0, base saturation, potential acidity, and exchangeable Al were related to the abundance of soil macrofaunal groups. The stability and biodiversity of soil macrofauna were highest in the LUS of NF, PP, and EP.

  14. Reclamation of a Degraded Coal-Mining Area with Perennial Cover Crops

    Directory of Open Access Journals (Sweden)

    Eloy Antonio Pauletto

    Full Text Available ABSTRACT: Studies addressing the potential of grass roots in improving the structural quality of constructed minesoils are not frequent in the literature, although they are essential for understanding the re-establishment of soil functions in the environment. The objective of this study was to quantify the root attributes of the species Urochloa humidicola, Panicum maximum, and Urochloa brizantha and relate them to the physical properties of a constructed minesoil in reclamation of an area degraded by coal mining. The study was performed in a field experiment in a coal mining area located in southern Brazil. Soil samples were collected, five years after experiment installation, to determine bulk density, macroporosity, distribution of water stable aggregates expressed in different size classes, mean weight diameter of water stable aggregates, and organic carbon content, as well as for chemical characterization. Root sampling was performed by the monolith method to a depth of 0.30 m. Results confirm the hypothesis that the root system of the perennial grasses studied positively contributes to recovery of the constructed minesoil in the 0.00-0.10 m layer after 58 months of revegetation. The higher percentage of large aggregates, higher bulk density, and lower macroporosity in the subsurface indicate the presence of degraded layers, negatively influencing the development of the grass root system. Urochloa brizantha exhibited the largest root matter in the surface layer, influencing the breakdown of the large and cohesive aggregates, transforming them into smaller crumbly aggregates. In the 0.10-0.20 m layer, Urochloa humidicola showed greater volume and root length in relation to other species; nevertheless, changes in soil physical properties were not observed, showing that the time span of the root growth of the species was not sufficient to provide improvements in the subsurface layers.

  15. SEQUENTIAL STOCHASTIC PRODUCTION DECISIONS FOR A PERENNIAL CROP: THE YIELD/QUALITY TRADEOFF FOR ALFALFA HAY

    OpenAIRE

    Blank, Steven C.; Orloff, Steve B.; Putnam, Daniel H.

    2001-01-01

    The "optimal cutting schedule" for alfalfa hay is described as a function of the trade-off between rising yield and falling quality of alfalfa over time and the local market prices being offered for different qualities of hay during the harvest season. Field test results quantify the yield/quality tradeoff for a California case study. A general decision rule is then derived to assist growers in making cutting decisions during a season. Finally, the optimal cutting schedule is shown to be the ...

  16. Bioenergy production from perennial energy crops: a consequential LCA of 12 bioenergy scenarios including land use changes.

    Science.gov (United States)

    Tonini, Davide; Hamelin, Lorie; Wenzel, Henrik; Astrup, Thomas

    2012-12-18

    In the endeavor of optimizing the sustainability of bioenergy production in Denmark, this consequential life cycle assessment (LCA) evaluated the environmental impacts associated with the production of heat and electricity from one hectare of Danish arable land cultivated with three perennial crops: ryegrass (Lolium perenne), willow (Salix viminalis) and Miscanthus giganteus. For each, four conversion pathways were assessed against a fossil fuel reference: (I) anaerobic co-digestion with manure, (II) gasification, (III) combustion in small-to-medium scale biomass combined heat and power (CHP) plants and IV) co-firing in large scale coal-fired CHP plants. Soil carbon changes, direct and indirect land use changes as well as uncertainty analysis (sensitivity, MonteCarlo) were included in the LCA. Results showed that global warming was the bottleneck impact, where only two scenarios, namely willow and Miscanthus co-firing, allowed for an improvement as compared with the reference (-82 and -45 t CO₂-eq. ha⁻¹, respectively). The indirect land use changes impact was quantified as 310 ± 170 t CO₂-eq. ha⁻¹, representing a paramount average of 41% of the induced greenhouse gas emissions. The uncertainty analysis confirmed the results robustness and highlighted the indirect land use changes uncertainty as the only uncertainty that can significantly change the outcome of the LCA results.

  17. Bee species diversity enhances productivity and stability in a perennial crop.

    Directory of Open Access Journals (Sweden)

    Shelley R Rogers

    Full Text Available Wild bees provide important pollination services to agroecoystems, but the mechanisms which underlie their contribution to ecosystem functioning--and, therefore, their importance in maintaining and enhancing these services-remain unclear. We evaluated several mechanisms through which wild bees contribute to crop productivity, the stability of pollinator visitation, and the efficiency of individual pollinators in a highly bee-pollination dependent plant, highbush blueberry. We surveyed the bee community (through transect sampling and pan trapping and measured pollination of both open- and singly-visited flowers. We found that the abundance of managed honey bees, Apis mellifera, and wild-bee richness were equally important in describing resulting open pollination. Wild-bee richness was a better predictor of pollination than wild-bee abundance. We also found evidence suggesting pollinator visitation (and subsequent pollination are stabilized through the differential response of bee taxa to weather (i.e., response diversity. Variation in the individual visit efficiency of A. mellifera and the southeastern blueberry bee, Habropoda laboriosa, a wild specialist, was not associated with changes in the pollinator community. Our findings add to a growing literature that diverse pollinator communities provide more stable and productive ecosystem services.

  18. Planning and costing adaptation of perennial crop systems to climate change: Coffee and banana in Rwanda

    Energy Technology Data Exchange (ETDEWEB)

    Ngabitsinze, Jean Chrysostome; Mukashema, Adrie; Ikirezi, Mireille; Niyitanga, Fidele

    2011-10-15

    The Rwandan economy is mainly based on agriculture. Since agricultural production in Rwanda depends almost exclusively on the quality of the rainy season and specific temperature ranges, it makes the country particularly vulnerable to climate variability and change. The study objective of evaluating and costing the most suitable climate change adaptation measures for this geographic context responds to the Rwandan Economic Development and Poverty Reduction Strategy, 2008-2012 (EDPRS) (MINECOFIN 2007), in which climate change and its adverse impacts were recently identified as a high priority. This study has particularly focused on coffee and banana farming systems and aimed at analysing shocks due to climate change from farmer to policymaker perspectives. The study found that in the last 30 years, Rwanda has experienced a series of climate fluctuations in terms of frequency, intensity, and persistence of existing extremes. Heavy rains, storms, heatwaves and droughts are the observed manifestations of climate change in specific areas of Rwanda. Changing weather patterns have an adverse impact on the country's agricultural production and thus on the country's GDP. Adaptation options for Rwanda include the following efficiency-enhancing agricultural interventions: 1. Adaption of crop calendars to new climate patterns (more effective distribution of inputs such as fertilizers and pesticides). 2. Investments in farming equipment. 3. Improvement of extension services and research. 4. Restructuring of the institutional frameworks and development plans. Integrated water resources management (IWRM); setting up information systems for early warning systems and rapid intervention mechanisms; intense agri-pastoral activities; and research on climate-resilient varieties were identified as primary requirements for agricultural adaption to climate change. In addition, developing alternative energy sources (e.g., substituting firewood) and the promotion of non

  19. California's Effort to Improve Almond Orchard Crop Coefficients

    Science.gov (United States)

    Sanden, B. L.; Fulton, A. E.; Munk, D. S.; Ewert, S.; Little, C.; Anderson, F.; Connell, J. H.; Rivera, M.; Orang, M. N.; Snyder, R. L.

    2012-04-01

    Almonds are a major agricultural commodity in California and optimal irrigation management is important for production, protecting the environment, and long term water resources planning. While evapotranspiration (ET) estimates are widely used for water resource planning, it is used less for "realtime" irrigation management for several reasons. One problem is the lack of confidence in the crop coefficient (Kc) values that are used with reference ET (ETo) to estimate well-watered crop ET (ETc). This is especially true for orchard crops. Until recently, the Kc values used to estimate the ETc of most orchard crops in California were derived using measurements of applied water, runoff, and soil water content depletion with the assumption that the trees were transpiring at a rate that was not restricted by water availability. For decades, a typical midseason Kc value used for clean-cultivated almond orchards was 0.90. Recently, a study was conducted by the University of California and the California Department of Water Resources to improve the Kc estimates for almond orchards; helping growers improve their on-farm water management for better production and less adverse impacts on the environment. Field experiments were conducted in four locations (Butte, Fresno, Kern, and Tehama Counties) spanning 1000 km north to south within the Central Valley of California over somewhat different climates. California Irrigation Management Information System (CIMIS) weather stations were used with the ASCE-EWRI standardized reference evapotranspiration equation for short canopies to determine ETo. Latent heat flux (LE), in all four orchards, was estimated using the residual of the energy balance equation: LE=Rn-G-H from measured net radiation (Rn), ground heat flux (G), and sensible heat flux (H) using surface renewal and eddy covariance measurements. The LE was divided by the latent heat of vaporization (L) to determine ETc. In three years of measurements in Kern County, the data

  20. Identifying obstacles and ranking common biological control research priorities for Europe to manage most economically important pests in arable, vegetable and perennial crops.

    Science.gov (United States)

    Lamichhane, Jay Ram; Bischoff-Schaefer, Monika; Bluemel, Sylvia; Dachbrodt-Saaydeh, Silke; Dreux, Laure; Jansen, Jean-Pierre; Kiss, Jozsef; Köhl, Jürgen; Kudsk, Per; Malausa, Thibaut; Messéan, Antoine; Nicot, Philippe C; Ricci, Pierre; Thibierge, Jérôme; Villeneuve, François

    2017-01-01

    EU agriculture is currently in transition from conventional crop protection to integrated pest management (IPM). Because biocontrol is a key component of IPM, many European countries recently have intensified their national efforts on biocontrol research and innovation (R&I), although such initiatives are often fragmented. The operational outputs of national efforts would benefit from closer collaboration among stakeholders via transnationally coordinated approaches, as most economically important pests are similar across Europe. This paper proposes a common European framework on biocontrol R&I. It identifies generic R&I bottlenecks and needs as well as priorities for three crop types (arable, vegetable and perennial crops). The existing gap between the market offers of biocontrol solutions and the demand of growers, the lengthy and expensive registration process for biocontrol solutions and their varying effectiveness due to variable climatic conditions and site-specific factors across Europe are key obstacles hindering the development and adoption of biocontrol solutions in Europe. Considering arable, vegetable and perennial crops, a dozen common target pests are identified for each type of crop and ranked by order of importance at European level. Such a ranked list indicates numerous topics on which future joint transnational efforts would be justified. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  1. Plant Stress Responses and Phenotypic Plasticity in the Epigenomics Era: Perspectives on the Grapevine Scenario, a Model for Perennial Crop Plants.

    Science.gov (United States)

    Fortes, Ana M; Gallusci, Philippe

    2017-01-01

    Epigenetic marks include Histone Post-Translational Modifications and DNA methylation which are known to participate in the programming of gene expression in plants and animals. These epigenetic marks may be subjected to dynamic changes in response to endogenous and/or external stimuli and can have an impact on phenotypic plasticity. Studying how plant genomes can be epigenetically shaped under stressed conditions has become an essential issue in order to better understand the molecular mechanisms underlying plant stress responses and enabling epigenetic in addition to genetic factors to be considered when breeding crop plants. In this perspective, we discuss the contribution of epigenetic mechanisms to our understanding of plant responses to biotic and abiotic stresses. This regulation of gene expression in response to environment raises important biological questions for perennial species such as grapevine which is asexually propagated and grown worldwide in contrasting terroirs and environmental conditions. However, most species used for epigenomic studies are annual herbaceous plants, and epigenome dynamics has been poorly investigated in perennial woody plants, including grapevine. In this context, we propose grape as an essential model for epigenetic and epigenomic studies in perennial woody plants of agricultural importance.

  2. Vulnerability of California specialty crops to projected mid-century temperature changes

    Science.gov (United States)

    Increasing global temperatures are likely to have major impacts on agriculture, but the effects will vary by crop and location. This paper describes the temperature sensitivity and exposure of selected specialty crops in California. We used literature synthesis to create several sensitivity indices ...

  3. Assessment of nutrient use in annual and perennial crops: a functional concept for analyzing nitrogen use efficiency

    OpenAIRE

    Weih, Martin; Asplund, Linnéa; Bergkvist, Göran

    2011-01-01

    The use of more nutrient-efficient crops is important for maintaining yields while enhancing environmental sustainability. Various approaches are being applied to evaluate aspects of plant nutrient use efficiency, among them ecological concepts based on accumulation and losses of biomass and nutrients, agronomic concepts with a major focus on agricultural crops and harvested products, and physiological approaches assessing single physiological processes important fo...

  4. The California Biomass Crop Adoption Model estimates biofuel feedstock crop production across diverse agro-ecological zones within the state, under different future climates

    Science.gov (United States)

    Kaffka, S.; Jenner, M.; Bucaram, S.; George, N.

    2012-12-01

    Both regulators and businesses need realistic estimates for the potential production of biomass feedstocks for biofuels and bioproducts. This includes the need to understand how climate change will affect mid-tem and longer-term crop performance and relative advantage. The California Biomass Crop Adoption Model is a partial mathematical programming optimization model that estimates the profit level needed for new crop adoption, and the crop(s) displaced when a biomass feedstock crop is added to the state's diverse set of cropping systems, in diverse regions of the state. Both yield and crop price, as elements of profit, can be varied. Crop adoption is tested against current farmer preferences derived from analysis of 10 years crop production data for all crops produced in California, collected by the California Department of Pesticide Regulation. Analysis of this extensive data set resulted in 45 distinctive, representative farming systems distributed across the state's diverse agro-ecological regions. Estimated yields and water use are derived from field trials combined with crop simulation, reported elsewhere. Crop simulation is carried out under different weather and climate assumptions. Besides crop adoption and displacement, crop resource use is also accounted, derived from partial budgets used for each crop's cost of production. Systematically increasing biofuel crop price identified areas of the state where different types of crops were most likely to be adopted. Oilseed crops like canola that can be used for biodiesel production had the greatest potential to be grown in the Sacramento Valley and other northern regions, while sugar beets (for ethanol) had the greatest potential in the northern San Joaquin Valley region, and sweet sorghum in the southern San Joaquin Valley. Up to approximately 10% of existing annual cropland in California was available for new crop adoption. New crops are adopted if the entire cropping system becomes more profitable. In

  5. Historical effects of temperature and precipitation on California crop yields

    Energy Technology Data Exchange (ETDEWEB)

    Lobell, D.B. [Energy and Environment Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Cahill, K.N. [Interdisciplinary Graduate Program in Environment and Resources, Stanford University, Stanford, CA 94305 (United States); Field, C.B. [Department of Global Ecology, Carnegie Institution, Stanford, CA 94305 (United States)

    2007-03-15

    For the 1980-2003 period, we analyzed the relationship between crop yield and three climatic variables (minimum temperature, maximum temperature, and precipitation) for 12 major Californian crops: wine grapes, lettuce, almonds, strawberries, table grapes, hay, oranges, cotton, tomatoes, walnuts, avocados, and pistachios. The months and climatic variables of greatest importance to each crop were used to develop regressions relating yield to climatic conditions. For most crops, fairly simple equations using only 2-3 variables explained more than two-thirds of observed yield variance. The types of variables and months identified suggest that relatively poorly understood processes such as crop infection, pollination, and dormancy may be important mechanisms by which climate influences crop yield. Recent climatic trends have had mixed effects on crop yields, with orange and walnut yields aided, avocado yields hurt, and most crops little affected by recent climatic trends. Yield-climate relationships can provide a foundation for forecasting crop production within a year and for projecting the impact of future climate changes.

  6. Super-races are not likely to dominate a fungal population within a life time of a perennial crop plantation of cultivar mixtures: a simulation study.

    Science.gov (United States)

    Xu, Xiangming

    2012-08-03

    Deployment of cultivars with different resistance in mixtures is one means to manage plant diseases and prolong the life of resistance genes. One major concern in adopting mixtures is the development of 'super-races' that can overcome many resistance genes present in the mixture. A stochastic simulation model was developed to study the dynamics of virulence alleles in two-cultivar mixtures of perennial crops, focusing on the effects of cost of virulence and pathogen reproduction mechanism. The simulated mechanism of virulence has characteristics of both major and minor genes. Random genetic drift due to repeated population crashes during the overwintering phase led to fixation of a single fungal genotype (in terms of its virulence), often within 100 seasons. Overall, cost of virulence is most important in determining the virulence dynamics under the present model formulation. With cost of virulence incorporated, nearly all simulation runs ended up with a single fungal genotype that can infect only one of the two cultivars. In absence of cost of virulence, most of the simulation runs ended up with fungal genotypes that can infect both host cultivars but in many cases do not contain the maximum possible number of virulence alleles due to random drift. A minimum of 20% sexual reproduction between strains from different cultivars is necessary to ensure that the final fixed strains are able to infect both cultivars. Although the number of virulence alleles in the final genotype and the time to fixation are affected by simulation factors, most of the variability was among replicate simulation runs (i.e. stochastic in nature). The time to fixation is generally long relative to cropping cycles. A single fungal genotype will dominate a population due to the bottleneck in overwintering with cost of virulence primarily determining whether the dominant genotype can infect both cultivars. However, the dominant genotype is unlikely to accumulate all the virulence alleles due to

  7. Super-races are not likely to dominate a fungal population within a life time of a perennial crop plantation of cultivar mixtures: a simulation study

    Directory of Open Access Journals (Sweden)

    Xu Xiangming

    2012-08-01

    Full Text Available Abstract Background Deployment of cultivars with different resistance in mixtures is one means to manage plant diseases and prolong the life of resistance genes. One major concern in adopting mixtures is the development of ‘super-races’ that can overcome many resistance genes present in the mixture. A stochastic simulation model was developed to study the dynamics of virulence alleles in two-cultivar mixtures of perennial crops, focusing on the effects of cost of virulence and pathogen reproduction mechanism. The simulated mechanism of virulence has characteristics of both major and minor genes. Results Random genetic drift due to repeated population crashes during the overwintering phase led to fixation of a single fungal genotype (in terms of its virulence, often within 100 seasons. Overall, cost of virulence is most important in determining the virulence dynamics under the present model formulation. With cost of virulence incorporated, nearly all simulation runs ended up with a single fungal genotype that can infect only one of the two cultivars. In absence of cost of virulence, most of the simulation runs ended up with fungal genotypes that can infect both host cultivars but in many cases do not contain the maximum possible number of virulence alleles due to random drift. A minimum of 20% sexual reproduction between strains from different cultivars is necessary to ensure that the final fixed strains are able to infect both cultivars. Although the number of virulence alleles in the final genotype and the time to fixation are affected by simulation factors, most of the variability was among replicate simulation runs (i.e. stochastic in nature. The time to fixation is generally long relative to cropping cycles. Conclusions A single fungal genotype will dominate a population due to the bottleneck in overwintering with cost of virulence primarily determining whether the dominant genotype can infect both cultivars. However, the dominant

  8. Growth and Metal Accumulation of an Alyssum murale Nickel Hyperaccumulator Ecotype Co-cropped with Alyssum montanum and Perennial Ryegrass in Serpentine Soil

    Directory of Open Access Journals (Sweden)

    Catherine Leigh Broadhurst

    2016-04-01

    Full Text Available The genus Alyssum (Brassicaceae contains Ni hyperaccumulators (50, many of which can achieve 30 g kg-1 Ni in dry leaf. Some Alyssum hyperaccumulators are viable candidates for commercial Ni phytoremediation and phytomining technologies. It is not known whether these species secrete organic and/or amino acids into the rhizosphere to solubilize Ni, or can make use of such acids within the soil to facilitate uptake. It has been hypothesized that in fields with mixed plant species, mobilization of metals by phytosiderophores secreted by Graminaceae plants could affect Alyssum Ni, Fe, Cu and Mn uptake.We co-cropped the Ni hyperaccumulator Alyssum murale, non-hyperaccumulator A. montanum and perennial ryegrass in a natural serpentine soil. All treatments had standard inorganic fertilization required for ryegrass growth and one treatment was compost amended. After 4 months A. murale leaves and stems contained 3600 mg kg-1 Ni which did not differ significantly with co-cropping. Overall Ni and Mn concentrations were significantly higher in A. murale than in A. montanum or L. perenne. Copper was not accumulated by either Alyssum species, but L. perenne accumulated up to 10 mg kg-1. A. montanum could not compete with either A. murale or ryegrass, and neither Alyssum species survived in the compost-amended soil. Co-cropping with ryegrass reduced Fe and Mn concentrations in A. murale but not to the extent of either increasing Ni uptake or affecting plant nutrition. The hypothesized Alyssum Ni accumulation in response to phytosiderophores secreted by co-cropped grass did not occur. Our data do not support increased mobilization of Mn by a phytosiderophore mechanism either, but the converse: mobilization of Mn by the Alyssum hyperaccumulator species significantly increased Mn levels in L. perenne. Tilling soil to maximize root penetration, adequate inorganic fertilization and appropriate plant densities are more important for developing efficient

  9. Developing the role of perennial forages for crop-livestock farms: a strategic multi-disciplinary approach

    NARCIS (Netherlands)

    Llewellyn, R.; Robertson, M.J.; Hayes, R.C.; Ferris, D.; Descheemaeker, K.K.E.; Revell, C.

    2014-01-01

    Developing new and improved grazing systems for crop–livestock farms where crop production is the major driver of farm management decisions presents a unique research and development challenge. In southern Australia, a substantial proportion of animal production from grazing comes from regions and

  10. 78 FR 46249 - Common Crop Insurance Regulations; Arizona-California Citrus Crop Insurance Provisions

    Science.gov (United States)

    2013-07-31

    ... the quality of the human environment, health, or safety. Therefore, neither an Environmental... the insurance period for lemons, by listing the counties: ``Southern California lemons (Imperial... no one will read this as meaning ``Southern California lemons'' is a separate citrus fruit commodity...

  11. Foliar Diseases of Apiaceae Crops in Coastal California

    Science.gov (United States)

    The number of outbreaks of leaf spot, blight and streak diseases on celery, cilantro, fennel and parsley has been increasing throughout central coastal California and particularly in Monterey County since 2002. Two different bacterial pathogens (Pseudomonas syringae pv. apii, and P. syringae pv. cor...

  12. Comparison of Satellite-based Basal and Adjusted Evapotranspiration for Several California Crops

    Science.gov (United States)

    Johnson, L.; Lund, C.; Melton, F. S.

    2013-12-01

    There is a continuing need to develop new sources of information on agricultural crop water consumption in the arid Western U.S. Pursuant to the California Water Conservation Act of 2009, for instance, the stakeholder community has developed a set of quantitative indicators involving measurement of evapotranspiration (ET) or crop consumptive use (Calif. Dept. Water Resources, 2012). Fraction of reference ET (or, crop coefficients) can be estimated from a biophysical description of the crop canopy involving green fractional cover (Fc) and height as per the FAO-56 practice standard of Allen et al. (1998). The current study involved 19 fields in California's San Joaquin Valley and Central Coast during 2011-12, growing a variety of specialty and commodity crops: lettuce, raisin, tomato, almond, melon, winegrape, garlic, peach, orange, cotton, corn and wheat. Most crops were on surface or subsurface drip, though micro-jet, sprinkler and flood were represented as well. Fc was retrospectively estimated every 8-16 days by optical satellite data and interpolated to a daily timestep. Crop height was derived as a capped linear function of Fc using published guideline maxima. These variables were used to generate daily basal crop coefficients (Kcb) per field through most or all of each respective growth cycle by the density coefficient approach of Allen & Pereira (2009). A soil water balance model for both topsoil and root zone, based on FAO-56 and using on-site measurements of applied irrigation and precipitation, was used to develop daily soil evaporation and crop water stress coefficients (Ke, Ks). Key meteorological variables (wind speed, relative humidity) were extracted from the California Irrigation Management Information System (CIMIS) for climate correction. Basal crop ET (ETcb) was then derived from Kcb using CIMIS reference ET. Adjusted crop ET (ETc_adj) was estimated by the dual coefficient approach involving Kcb, Ke, and incorporating Ks. Cumulative ETc

  13. Estimation of actual evapotranspiration of Mediterranean perennial crops by means of remote-sensing based surface energy balance models

    Directory of Open Access Journals (Sweden)

    G. Rallo

    2009-07-01

    Full Text Available Actual evapotranspiration from typical Mediterranean crops has been assessed in a Sicilian study area by using surface energy balance (SEB and soil-water balance models. Both modelling approaches use remotely sensed data to estimate evapotranspiration fluxes in a spatially distributed way. The first approach exploits visible (VIS, near-infrared (NIR and thermal (TIR observations to solve the surface energy balance equation whereas the soil-water balance model uses only VIS-NIR data to detect the spatial variability of crop parameters. Considering that the study area is characterized by typical spatially sparse Mediterranean vegetation, i.e. olive, citrus and vineyards, alternating bare soil and canopy, we focused the attention on the main conceptual differences between one-source and two-sources energy balance models. Two different models have been tested: the widely used one-source SEBAL model, where soil and vegetation are considered as the sole source (mostly appropriate in the case of uniform vegetation coverage and the two-sources TSEB model, where soil and vegetation components of the surface energy balance are treated separately. Actual evapotranspiration estimates by means of the two surface energy balance models have been compared vs. the outputs of the agro-hydrological SWAP model, which was applied in a spatially distributed way to simulate one-dimensional water flow in the soil-plant-atmosphere continuum. Remote sensing data in the VIS and NIR spectral ranges have been used to infer spatially distributed vegetation parameters needed to set up the upper boundary condition of SWAP. Actual evapotranspiration values obtained from the application of the soil water balance model SWAP have been considered as the reference to be used for energy balance models accuracy assessment.

    Airborne hyperspectral data acquired during a NERC (Natural Environment Research Council, UK campaign in 2005 have been used. The results of this

  14. Classical Biological Control of Invasive Legacy Crop Pests: New Technologies Offer Opportunities to Revisit Old Pest Problems in Perennial Tree Crops

    Directory of Open Access Journals (Sweden)

    Mark S. Hoddle

    2014-12-01

    Full Text Available Advances in scientific disciplines that support classical biological control have provided “new tools” that could have important applications for biocontrol programs for some long-established invasive arthropod pests. We suggest that these previously unavailable tools should be used in biological control programs targeting “legacy pests”, even if they have been targets of previously unsuccessful biocontrol projects. Examples of “new tools” include molecular analyses to verify species identities and likely geographic area of origin, climate matching and ecological niche modeling, preservation of natural enemy genetic diversity in quarantine, the use of theory from invasion biology to maximize establishment likelihoods for natural enemies, and improved understanding of the interactions between natural enemy and target pest microbiomes. This review suggests that opportunities exist for revisiting old pest problems and funding research programs using “new tools” for developing biological control programs for “legacy pests” could provide permanent suppression of some seemingly intractable pest problems. As a case study, we use citricola scale, Coccus pseudomagnoliarum, an invasive legacy pest of California citrus, to demonstrate the potential of new tools to support a new classical biological control program targeting this insect.

  15. Perennial Pepperweed Patches - San Francisco Estuary [ds295

    Data.gov (United States)

    California Department of Resources — This layer contains polygon data for the perennial pepperweed (Lepidium latifolium) database. This database represents distribution data collected within the areas...

  16. Assessment of Climate Change Impacts on Agricultural Water Demands and Crop Yields in California's Central Valley

    Science.gov (United States)

    Tansey, M. K.; Flores-Lopez, F.; Young, C. A.; Huntington, J. L.

    2012-12-01

    Long term planning for the management of California's water resources requires assessment of the effects of future climate changes on both water supply and demand. Considerable progress has been made on the evaluation of the effects of future climate changes on water supplies but less information is available with regard to water demands. Uncertainty in future climate projections increases the difficulty of assessing climate impacts and evaluating long range adaptation strategies. Compounding the uncertainty in the future climate projections is the fact that most readily available downscaled climate projections lack sufficient meteorological information to compute evapotranspiration (ET) by the widely accepted ASCE Penman-Monteith (PM) method. This study addresses potential changes in future Central Valley water demands and crop yields by examining the effects of climate change on soil evaporation, plant transpiration, growth and yield for major types of crops grown in the Central Valley of California. Five representative climate scenarios based on 112 bias corrected spatially downscaled CMIP 3 GCM climate simulations were developed using the hybrid delta ensemble method to span a wide range future climate uncertainty. Analysis of historical California Irrigation Management Information System meteorological data was combined with several meteorological estimation methods to compute future solar radiation, wind speed and dew point temperatures corresponding to the GCM projected temperatures and precipitation. Future atmospheric CO2 concentrations corresponding to the 5 representative climate projections were developed based on weighting IPCC SRES emissions scenarios. The Land, Atmosphere, and Water Simulator (LAWS) model was used to compute ET and yield changes in the early, middle and late 21st century for 24 representative agricultural crops grown in the Sacramento, San Joaquin and Tulare Lake basins. Study results indicate that changes in ET and yield vary

  17. Ambient and elevated carbon dioxide on growth, physiological and nutrient uptake parameters of perennial leguminous cover crops under low light intensities

    Science.gov (United States)

    Adaptability and optimum growth of cover crops in plantation crops is affected by the inherent nature of the cover crop species and the light intensity at canopy levels. Globally concentrations of atmospheric CO2 are increasing and this creates higher photosynthesis and nutrient demand by crops as l...

  18. Effect of harvest timing on leaf production and yield of diterpene glycosides in Stevia rebaudiana Bert: a specialty perennial crop for Mississippi

    Science.gov (United States)

    Stevia rebaundiana (Bertoni), a perennial shrub of the Asteraceae, is one of the most important sources of non-caloric natural sweeteners. Stevia’s plant extracts and glycosides have been used for several years in Paraguay and Brazil. Several studies suggest that Stevia and its glycosides exert ben...

  19. Utilization of GIS/GPS-Based Information Technology in Commercial Crop Decision Making in California, Washington, Oregon, Idaho, and Arizona.

    Science.gov (United States)

    Thomas, C S; Skinner, P W; Fox, A D; Greer, C A; Gubler, W D

    2002-09-01

    Ground-based weather, plant-stage measurements, and remote imagery were geo-referenced in geographic information system (GIS) software using an integrated approach to determine insect and disease risk and crop cultural requirements. Weather forecasts and disease weather forecasts for agricultural areas were constructed with elevation, weather, and satellite data. Models for 6 insect pests and 12 diseases of various crops were calculated and presented daily in georeferenced maps for agricultural areas in northern California and Washington. Grape harvest dates and yields also were predicted with high accuracy. The data generated from the GIS global positioning system (GPS) analyses were used to make management decisions over a large number of acres in California, Washington, Oregon, Idaho, and Arizona. Information was distributed daily over the Internet as regional weather, insect, and disease risk maps as industry-sponsored or subscription-based products. Use of GIS/GPS technology for semi-automated data analysis is discussed.

  20. Agricultural damages and losses from ARkStorm scenario flooding in California

    Science.gov (United States)

    Wein, Anne; David Mitchell,; Peters, Jeff; John Rowden,; Johnny Tran,; Alessandra Corsi,; Dinitz, Laura B.

    2016-01-01

    Scientists designed the ARkStorm scenario to challenge the preparedness of California communities for widespread flooding with a historical precedence and increased likelihood under climate change. California is an important provider of vegetables, fruits, nuts, and other agricultural products to the nation. This study analyzes the agricultural damages and losses pertaining to annual crops, perennial crops, and livestock in California exposed to ARkStorm flooding. Statewide, flood damage is incurred on approximately 23% of annual crop acreage, 5% of perennial crop acreage, and 5% of livestock, e.g., dairy, feedlot, and poultry, acreage. The sum of field repair costs, forgone income, and product replacement costs span $3.7 and $7.1 billion (2009) for a range of inundation durations. Perennial crop loss estimates dominate, and the vulnerability of orchards and vineyards has likely increased with recent expansion. Crop reestablishment delays from levee repair and dewatering more than double annual crop losses in the delta islands, assuming the fragile system does not remain permanently flooded. The exposure of almost 200,000 dairy cows to ARkStorm flooding poses livestock evacuation challenges. Read More: http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29NH.1527-6996.0000174

  1. Brachypodium sylvaticum, a Model for Perennial Grasses: Transformation and Inbred Line Development

    OpenAIRE

    Steinwand, Michael A; Hugh A Young; Bragg, Jennifer N.; Tobias, Christian M.; Vogel, John P

    2013-01-01

    Perennial species offer significant advantages as crops including reduced soil erosion, lower energy inputs after the first year, deeper root systems that access more soil moisture, and decreased fertilizer inputs due to the remobilization of nutrients at the end of the growing season. These advantages are particularly relevant for emerging biomass crops and it is projected that perennial grasses will be among the most important dedicated biomass crops. The advantages offered by perennial cro...

  2. Characteristics of AVIRIS bands measurements in agricultural crops at Blythe area, California: III. Studies on Teff Grass

    Science.gov (United States)

    Shakir Hanna, Safwat H.; Rethwisch, Michael D.

    2003-03-01

    AVIRIS data from Blythe were acquired in June 1997 to study the agricultural spectra from different crops and for identification of crops in other areas with similar environmental factors and similar spectral properties. In this respect; the main objectives of this study are: 1) to compare the spectral and radiometric characteristics of AVIRIS data from agriculture crops with the spectra measured by FieldSpec ASD radiometer; 2) to explore the use of AVIRIS images in identifying agricultural crops; 3) to study the impact of environmental factors on selected crops and; 4) to build a spectral library for the crops that were studied. A long-term goal is to extend the spectral library for different vegetation or crops in different stages of growth. In order to support our study, on July 18-19, 2000 we collected spectra using the FieldSpec spectrometer from selected fields planted with different crops at Blythe area, California (at the Longitude 114° 33.28 W and Latitude 33° 25.42 N to Longitude of 114° 44.53 W and 33° 39.77 N Latitude. The teff grass spectra were studied. Teff grass fields were treated with different types of irrigation (i.e. wet to dry conditions). Additional parameters were studied such as the soil water content (WC), pH, organic matter (OM) and nitrogen (N%). The results of this study showed that there is a significant correlation between the data that were collected by AVIRIS image scene in 1997 and spectral data collected by the FieldSpec spectrometer. This correlation allowed us to build a spectral library to be used in ENVI-IDL software. This leads to identification of different crops and in particular the visible part of the spectra. AVIRIS data are in agreement with FieldSpec data. Using IDL algorithms of Spectral Angle Mapper classification (SAM), Spectral Feature Fitting (SFF) and Spectral Binary Encoding (SPE) showed that there is an excellent agreement between the predicted and the actual crop type (i.e. the correlation is between 85

  3. Impact of cash cropping and perennial crops on food crop ...

    African Journals Online (AJOL)

    Commission for Africa, and the director of the African Centre for Economic and Historical Studies (an independent research ... part conditional on a given structure of the economy, known outcome targets, and well-defined instruments. ..... the state. In practice, policy agency is dispersed among a set of institutions. Each of.

  4. Impact of cash cropping and perennial crops on food crop ...

    African Journals Online (AJOL)

    Building and updating macro-econometric models require forecasting and planning experts ... functions) and two import demand functions (capital goods import and raw material imports, and consumers good ... assumption on government current expenditure and agricultural price is questionable. In the case where the ...

  5. Impact of cash cropping and perennial crops on food crop ...

    African Journals Online (AJOL)

    Using survey data collected from 1500 rural households in 1994 and 1997, this ... on Latin America; Food Policy, 2001 on Africa, and Agricultural Economics, 2006 on ... and globally, removed some trade barriers, lifted quantitative restrictions on trade and ... Others argue that farmers simply respond to underlying trends and.

  6. Characteristics of AVIRIS bands measurements in agricultural: crops at Blythe Area, California: IV: studies on cotton varieties spectral data

    Science.gov (United States)

    Shakir Hanna, Safwat H.; Rethwisch, Michael D.

    2004-02-01

    AVIRIS data from Blythe were acquired in June 1997 to study the agricultural spectra from different crops and for identification of crops in other areas with similar environmental factors and similar spectral properties. The main objectives of this study are: 1) to compare the spectral and radiometric characteristics of AVIRIS data from verities of cotton crop with the spectra measured by FieldSpecR ASD radiometer; 2) to explore the use of AVIRIS images in identifying agricultural crops; 3) to study the impact of environmental factors on selected crops and; 4) to build a spectral library for the cotton crop varieties that were studied. A long-term goal is to extend the spectral library for different vegetation or crops in different stages of growth or different varieties. In order to support our study, on June 26, 2001 we collected spectral data using the FieldSpec spectrometer from selected fields planted with different cotton varieties at Blythe area, California (at the Longitude 114° 41.88 W and Latitude 33° 24.27N to Longitude 114° 41.86 W and Latitude 33° 24.00N). The spectral data of cotton varieties were studied. Environmental parameters were studied such as the soil water content (WC), pH, organic matter (OM), C% and nitrogen (N%). The results of this study showed that there were differences in the signatures of different cotton varieties. Also, there was a significant correlation between the data that were collected by AVIRIS image scene in 1997 and spectral data collected by the FieldSpec spectrometer. This correlation allowed us to build a spectral library to be used in ENVI-IDL software. This leads to identification of different cotton varieties and in particular the visible part of the spectra. AVIRIS data are in agreement with FieldSpec data. Using IDL algorithms of Spectral Angle Mapper classification (SAM), Spectral Feature Fitting (SFF) and Spectral Binary Encoding (SPE) showed that there is an excellent agreement between the predicted and the

  7. Recharging California's Groundwater: Crop Suitability and Surface Water Availability for Agricultural Groundwater Banking

    Science.gov (United States)

    Dahlke, H. E.; Kocis, T. N.; Brown, A.

    2016-12-01

    Groundwater banking, the intentional recharge of groundwater from surface water for storage and recovery, is an important conjunctive use strategy for water management in California (CA). A largely unexplored approach to groundwater banking, agricultural groundwater banking (ag-GB), utilizes flood flows and agricultural lands (alfalfa/pasture) for recharging groundwater. Understanding soil suitability for ag-GB, crop health and flooding tolerance, leaching of soil nitrate and salts, the availability of surface water for recharge, and the economic costs and benefits of ag-GB is fundamental to assessing the feasibility of local-scale implementation of ag-GB. The study presented here considers both the availability of excess streamflow (e.g., the magnitude, frequency, timing, and duration of winter flood flow) for ag-GB and the risks and benefits associated with using alfalfa fields as spreading grounds for ag-GB. The availability of surface water for winter (Nov to Apr) ag-GB were estimated based on daily streamflow records for 93 stream gauges within the Central Valley, CA. Analysis focused on high-magnitude (>90thpercentile) flows because most lower flows are likely legally allocated in CA. Results based >50 years of data indicate that an average winter/spring (Nov. - Apr.) in the Sacramento River Basin could provide 7 million acre-feet (AF) (8.6 km3) of water for ag-GB from flows above the 90th percentile. These flows originate from few storm events (5-7 events) and occur on average for 25-30 days between November and April. Wintertime on-farm recharge experiments were conducted on a 9-yr old, 15-acre alfalfa field in the Scott Valley, CA, where 135 AF and 107 AF of water were recharged during the winters of 2015 and 2016, respectively. Biomass data collected indicates that pulsed application of 6-10 ft of water on dormant alfalfa results in minimal yield loss (0.5 ton/acre reduction), short-duration saturated conditions in the root-zone, and high recharge

  8. Field-scale and Regional Variability in Evapotranspiration over Crops in California using Eddy Covariance and Surface Renewal

    Science.gov (United States)

    Kent, E. R.; Clay, J. M.; Leinfelder-Miles, M.; Lambert, J. J.; Little, C.; Monteiro, R. O. C.; Monteiro, P. F. C.; Shapiro, K.; Rice, S.; Snyder, R. L.; Daniele, Z.; Paw U, K. T.

    2016-12-01

    Evapotranspiration (ET) estimated using a single crop coefficient and a grass reference largely ignores variability due to heterogeneity in microclimate, soils, and crop management. We employ a relatively low cost energy balance residual method using surface renewal and eddy covariance measurements to continuously estimate half-hourly and daily ET across more than 15 fields and orchards spanning four crops and two regions of California. In the Sacramento-San Joaquin River Delta, measurements were taken in corn, pasture, and alfalfa fields, with 4-5 stations in each crop type spread across the region. In the Southern San Joaquin Valley, measurements were taken in three different pistachio orchards, with one orchard having six stations instrumented to examine salinity-induced heterogeneity. We analyze field-scale and regional variability in ET and measured surface energy balance components. Cross comparisons between the eddy covariance and the surface renewal measurements confirm the robustness of the surface renewal method. A hybrid approach in which remotely sensed net radiation is combined with in situ measurements of sensible heat flux is also investigated. This work will provide ground-truth data for satellite and aerial-based ET estimates and will inform water management at the field and regional scales.

  9. Perennial wheat lines have highly admixed population structure and elevated rates of outcrossing.

    Science.gov (United States)

    Perennial wheat has been proposed to alleviate long standing issues with soil erosion in annual cropping systems, while supporting rural communities and providing grain farmers with a marketable climate-resilient crop. The Washington State University perennial wheat breeding program has created sev...

  10. Cultivar and row distance interactions in perennial ryegrass

    DEFF Research Database (Denmark)

    Deleuran, Lise C; Gislum, René; Boelt, Birte

    2009-01-01

    To gain information about how widening of the row distance influences seed yields in first-year perennial ryegrass, experiments with four row distances in three types of perennial ryegrass were conducted at the University of Aarhus, Faculty of Agricultural Sciences. Perennial ryegrass was undersown...... at 12-, 24-, 36-, or 48-cm row distance in a cover crop of spring barley. The seeding rate in perennial ryegrass was 6 kg seeds ha-1 regardless of row distance. Although increasing the row distance from 12 to 48 cm had a negative effect on the yield component number of reproductive tillers, the yield...... was not affected in the first-year seed production in three perennial ryegrass cultivars. Regardless of row distance the seed rate was 6 kg ha-1 and hence in-row plant density in autumn and spring was higher at 48 compared with 12 cm; however, in all three cultivars the highest number of reproductive tillers...

  11. Leguminosas herbáceas perenes para utilização como coberturas permanentes de solo na Caatinga Mineira Perennial herbaceous legumes used as permanent cover cropping in the Caatinga Mineira

    Directory of Open Access Journals (Sweden)

    Ricardo Borges Teodoro

    2011-06-01

    Full Text Available O presente trabalho objetivou avaliar o comportamento e as potencialidades de leguminosas herbáceas perenes para o uso como cobertura permanente em solos da região da Caatinga Mineira, Médio Vale do Jequitinhonha, MG, visando a introdução dessas plantas de cobertura em áreas agrícolas. O experimento foi conduzido de dezembro de 2008 a julho de 2009. O delineamento experimental foi em blocos ao acaso, com seis tratamentos e quatro repetições. Os tratamentos foram constituídos pelas leguminosas: cudzu tropical (Pueraria phaseoloides, calopogônio (Calopogonium mucunoides, amendoim forrageiro (Arachis pintoi, soja perene (Glycine wightii, estilosantes (Stylosanthes capitata, Stylosanthes macrocephala e pela testemunha (sem a presença de leguminosa. Foram avaliados os seguintes parâmetros: emergência das plântulas; taxa de cobertura do solo; promoção da retenção de umidade e temperatura do solo; capacidade de inibição da vegetação espontânea; potencial de deposição de folhas e de aporte de macronutrientes pela senescência de folhas; produção total de fitomassa seca e acúmulo de macronutrientes na parte aérea. A cobertura plena do solo foi alcançada pelo calopogônio, amendoim forrageiro e cudzu tropical. O calopogônio conferiu maior capacidade de retenção da umidade e inibição das plantas espontâneas. Em todos os tratamentos com leguminosas a temperatura do solo foi inferior à testemunha, a partir dos 120 dias de ciclo. Na região da Caatinga Mineira, as leguminosas perenes calopogônio e cudzu tropical, podem contribuir significativamente para o incremento de nitrogênio, aporte de outros macronutrientes (K, P, Ca e Mg e incremento da matéria orgânica do solo.The study objective was to evaluate the performance and potential of perennial herbaceous legumes for use as permanent soil cover in the Caatinga Mineira region MG, Brazil, for the introduction of these cover crops in agricultural areas. The experimental

  12. Perennial roots to immortality.

    Science.gov (United States)

    Munné-Bosch, Sergi

    2014-10-01

    Maximum lifespan greatly varies among species, and it is not strictly determined; it can change with species evolution. Clonal growth is a major factor governing maximum lifespan. In the plant kingdom, the maximum lifespans described for clonal and nonclonal plants vary by an order of magnitude, with 43,600 and 5,062 years for Lomatia tasmanica and Pinus longaeva, respectively. Nonclonal perennial plants (those plants exclusively using sexual reproduction) also present a huge diversity in maximum lifespans (from a few to thousands of years) and even more interestingly, contrasting differences in aging patterns. Some plants show a clear physiological deterioration with aging, whereas others do not. Indeed, some plants can even improve their physiological performance as they age (a phenomenon called negative senescence). This diversity in aging patterns responds to species-specific life history traits and mechanisms evolved by each species to adapt to its habitat. Particularities of roots in perennial plants, such as meristem indeterminacy, modular growth, stress resistance, and patterns of senescence, are crucial in establishing perenniality and understanding adaptation of perennial plants to their habitats. Here, the key role of roots for perennial plant longevity will be discussed, taking into account current knowledge and highlighting additional aspects that still require investigation. © 2014 American Society of Plant Biologists. All Rights Reserved.

  13. Trade-offs between seed output and life span - a quantitative comparison of traits between annual and perennial congeneric species.

    Science.gov (United States)

    Vico, Giulia; Manzoni, Stefano; Nkurunziza, Libère; Murphy, Kevin; Weih, Martin

    2016-01-01

    Perennial plants allocate more resources belowground, thus sustaining important ecosystem services. Hence, shifting from annual to perennial crops has been advocated towards a more sustainable agriculture. Nevertheless, wild perennial species have lower seed production than selected annuals, raising the questions of whether there is a fundamental trade-off between reproductive effort and life span, and whether such trade-off can be overcome through selection. In order to address these questions and to isolate life span from phylogenetic and environmental factors, we conducted a meta-analysis encompassing c. 3000 congeneric annual/perennial pairs from 28 genera. This meta-analysis is complemented with a minimalist model of long-term productivity in perennial species. Perennials allocate more resources belowground and less to seeds than congeneric annuals, independently of selection history. However, existing perennial wheat and rice could achieve yields similar to annuals if they survived three years and each year doubled their biomass, as other perennial grasses do. Selected perennial crops maintain the large belowground allocation of wild perennials, and thus can provide desired regulatory ecosystem services. To match the seed yield of annuals, biomass production of perennial grains must be increased to amounts attained by some perennial grasses - if this goal can be met, perennial crops can provide a more sustainable alternative to annuals. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  14. Pityophthorus orarius Bright (Coleoptera: Scolytidae) in a northern California Douglas-fir seed orchard: effect of clone, tree vigor, and cone crop on rate of attack

    Science.gov (United States)

    Nancy G. Rappaport; David L. Wood

    1994-01-01

    The geographic range of the Douglas-fir twig beetle, Pityophthorus orarius Bright, was extended beyond the original provenance of southern British Columbia to northern California. A survey of 457 Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] trees in 1985 revealed that those with heavy cone crops were more likely to be...

  15. 7 CFR 457.121 - Arizona-California citrus crop insurance provisions.

    Science.gov (United States)

    2010-01-01

    ..., production will be converted to cartons on the basis of the following average net pounds of packed fruit in a standard packed carton. Container size Fruit crop Pounds Container #58 Navel oranges, Valencia oranges & Sweet oranges 38 Container #58 Lemons 40 Container #59 Grapefruit 32 Container #63 Tangerines (including...

  16. Seasonal and diel environmental conditions predict western pond turtle (Emys marmorata) behavior at a perennial and an ephemeral stream in Sequoia National Park, California

    Science.gov (United States)

    Ruso, Gabrielle; Meyer, Erik; Das, Adrian J.

    2017-01-01

    Managers making decisions may benefit from a well-informed understanding of a species' population size and trends. Given the cryptic nature and habitat characteristics of the western pond turtle (Emys marmorata), however, imperfect detection may be high and population estimates are frequently varied and unreliable. As a case study to investigate this issue, we used temperature dataloggers to examine turtle behavior at 2 long-term monitoring sites with different hydrological characteristics in Sequoia National Park, California, to determine if common stream-survey techniques are consistent with site-specific turtle behavior. Sycamore Creek is an intermittent stream that dries up every summer while the North Fork Kaweah River flows year-round. We found that while turtles spent most of the recorded time in the water (55% in Sycamore Creek and 82% in the North Fork Kaweah River), the timing of traditional surveys only coincided with the turtles' aquatic activity in the North Fork Kaweah River. At Sycamore Creek, turtles were most likely to be in the water at night. In contrast, failure to detect turtles in North Fork Kaweah River is likely owing to the larger size and complexity of the underwater habitat. In both streams, turtles were also more likely to be in the water in the weeks leading up to important changes in hydroperiods. Our findings illustrate the effects that differences in water permanence can have on turtle behavior within the same watershed and how phenotypic plasticity may then affect detection during surveys. Our study highlights the importance of tailoring survey practices to the site-specific behavioral traits of the target species.

  17. Using Plant Growth Regulators on Containerized Herbaceous Perennials

    OpenAIRE

    Latimer, Joyce G.; Scoggins, Holly Lynne, 1962-

    2012-01-01

    Explains the factors to consider when selecting and using plant growth regulators, chemicals designed to affect plant growth and/or development, in order to achieve best results on herbaceous perennials grown in containers and includes an appendix listing plant growth regulators by crop type.

  18. Vasomotor (perennial chronic) conjunctivitis.

    Science.gov (United States)

    Bielory, Leonard

    2006-10-01

    To increase the awareness of nonimmunoglobulin E-mediated conjunctival disorders similar to those recognized to affect other organs that are targets in immunoglobulin E-mediated disorders. Such conditions may include 'vasomotor' instability, that is vasomotor conjunctivitis, which leads to a more common perennial chronic conjunctivitis. These conditions are not commonly included in the differential diagnosis of allergic conjunctivitis. Although there have not been specific recent findings regarding the eye, it appears that evidence for such disorders in the rhinitis literature suggests that they can be involved in more than 25% of chronic conjunctivitis cases. The extrapolation of such conditions to the conjunctival surface clearly reflects these syndromes which have clearly been underappreciated and underdiagnosed. A significant amount of work remains to be performed to understand perennial chronic conjunctivitis (vasomotor conjunctivitis or nonallergic noninfectious conjunctivitis) as well as other forms of chronic conjunctivitis that can mimic or exist in a comorbid state with ocular allergy. These disorders need to be better defined, categorized and classified to determine the best treatment modalities. Management guidelines and parameters of chronic noninfectious conjunctivitis need to be set on a national and international basis that will advance clinically applicable research results, pharmaceutical development and relief for patients.

  19. Nature-based agricultural solutions: Scaling perennial grains across Africa.

    Science.gov (United States)

    Peter, Brad G; Mungai, Leah M; Messina, Joseph P; Snapp, Sieglinde S

    2017-11-01

    Modern plant breeding tends to focus on maximizing yield, with one of the most ubiquitous implementations being shorter-duration crop varieties. It is indisputable that these breeding efforts have resulted in greater yields in ideal circumstances; however, many farmed locations across Africa suffer from one or more conditions that limit the efficacy of modern short-duration hybrids. In view of global change and increased necessity for intensification, perennial grains and long-duration varieties offer a nature-based solution for improving farm productivity and smallholder livelihoods in suboptimal agricultural areas. Specific conditions where perennial grains should be considered include locations where biophysical and social constraints reduce agricultural system efficiency, and where conditions are optimal for crop growth. Using a time-series of remotely-sensed data, we locate the marginal agricultural lands of Africa, identifying suboptimal temperature and precipitation conditions for the dominant crop, i.e., maize, as well as optimal climate conditions for two perennial grains, pigeonpea and sorghum. We propose that perennial grains offer a lower impact, sustainable nature-based solution to this subset of climatic drivers of marginality. Using spatial analytic methods and satellite-derived climate information, we demonstrate the scalability of perennial pigeonpea and sorghum across Africa. As a nature-based solution, we argue that perennial grains offer smallholder farmers of marginal lands a sustainable solution for enhancing resilience and minimizing risk in confronting global change, while mitigating social and edaphic drivers of low and variable production. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Linking resilience theory and diffusion of innovations theory to understand the potential for perennials in the U.S. Corn Belt

    Science.gov (United States)

    Ryan C. Atwell; Lisa A. Schulte; Lynne M. Westphal

    2009-01-01

    In the last 200 yr, more than 80% of the land in the U.S. Corn Belt agro-ecosystem has been converted from natural perennial vegetation to intensive agricultural production of row crops. Despite research showing how re-integration of perennial vegetation, e.g., cover crops, pasture, riparian buffers, and restored wetlands, at strategic landscape positions can bolster...

  1. Brachypodium sylvaticum, a model for perennial grasses: transformation and inbred line development.

    Science.gov (United States)

    Steinwand, Michael A; Young, Hugh A; Bragg, Jennifer N; Tobias, Christian M; Vogel, John P

    2013-01-01

    Perennial species offer significant advantages as crops including reduced soil erosion, lower energy inputs after the first year, deeper root systems that access more soil moisture, and decreased fertilizer inputs due to the remobilization of nutrients at the end of the growing season. These advantages are particularly relevant for emerging biomass crops and it is projected that perennial grasses will be among the most important dedicated biomass crops. The advantages offered by perennial crops could also prove favorable for incorporation into annual grain crops like wheat, rice, sorghum and barley, especially under the dryer and more variable climate conditions projected for many grain-producing regions. Thus, it would be useful to have a perennial model system to test biotechnological approaches to crop improvement and for fundamental research. The perennial grass Brachypodiumsylvaticum is a candidate for such a model because it is diploid, has a small genome, is self-fertile, has a modest stature, and short generation time. Its close relationship to the annual model Brachypodiumdistachyon will facilitate comparative studies and allow researchers to leverage the resources developed for B. distachyon. Here we report on the development of two keystone resources that are essential for a model plant: high-efficiency transformation and inbred lines. Using Agrobacterium tumefaciens-mediated transformation we achieved an average transformation efficiency of 67%. We also surveyed the genetic diversity of 19 accessions from the National Plant Germplasm System using SSR markers and created 15 inbred lines.

  2. Brachypodium sylvaticum, a model for perennial grasses: transformation and inbred line development.

    Directory of Open Access Journals (Sweden)

    Michael A Steinwand

    Full Text Available Perennial species offer significant advantages as crops including reduced soil erosion, lower energy inputs after the first year, deeper root systems that access more soil moisture, and decreased fertilizer inputs due to the remobilization of nutrients at the end of the growing season. These advantages are particularly relevant for emerging biomass crops and it is projected that perennial grasses will be among the most important dedicated biomass crops. The advantages offered by perennial crops could also prove favorable for incorporation into annual grain crops like wheat, rice, sorghum and barley, especially under the dryer and more variable climate conditions projected for many grain-producing regions. Thus, it would be useful to have a perennial model system to test biotechnological approaches to crop improvement and for fundamental research. The perennial grass Brachypodiumsylvaticum is a candidate for such a model because it is diploid, has a small genome, is self-fertile, has a modest stature, and short generation time. Its close relationship to the annual model Brachypodiumdistachyon will facilitate comparative studies and allow researchers to leverage the resources developed for B. distachyon. Here we report on the development of two keystone resources that are essential for a model plant: high-efficiency transformation and inbred lines. Using Agrobacterium tumefaciens-mediated transformation we achieved an average transformation efficiency of 67%. We also surveyed the genetic diversity of 19 accessions from the National Plant Germplasm System using SSR markers and created 15 inbred lines.

  3. 75 FR 65995 - Biomass Crop Assistance Program

    Science.gov (United States)

    2010-10-27

    ..., greater description of forestry resources, agricultural plastics, more precise definitions of eligible.... Perennial crops, and the use of corn stover and wheat straw, would shift away from conventional tillage to...

  4. Combined production of free-range pigs and energy crops – animal behaviour and crop damages

    DEFF Research Database (Denmark)

    Horsted, Klaus; Kongsted, Anne Grete; Jørgensen, Uffe

    2012-01-01

    Intensive free-range pig production on open grasslands has disadvantages in that it creates nutrient hotspots and little opportunity for pigs to seek shelter from the sun. Combining a perennial energy crop and pig production might benefit the environment and animal welfare because perennial energy...

  5. Distribution and incidence of atoxigenic Aspergillus flavus VCG in tree crop orchards in California: a strategy for identifying potential antagonists

    Science.gov (United States)

    To identify predominant isolates for potential use as biocontrol agents, Aspergillus flavus isolates collected soils of almond, pistachio and fig orchard in the Central Valley of California were tested for their membership to 16 atoxigenic vegetative compatibility groups(VCGs), including YV36, the V...

  6. Establishment techniques in under-sown perennial ryegrass for seed production

    DEFF Research Database (Denmark)

    Deleuran, Lise C; Boelt, Birte

    2009-01-01

    Establishment methods have proven to be of major importance for grass-seed production. The objective of this research was to test the effect of different sowing techniques on plant establishment and the subsequent seed yield. Perennial ryegrass (Lolium perenne L.) is used as the model grass due...... to its large importance in Danish agriculture. In a three-year trial six different methods of under-sowing of perennial ryegrass in a spring barley cover crop were employed. Perennial ryegrass was either sown directly at different depths within the spring barley (Hordeum vulgare L.) rows or placed 2, 6...... ryegrass when placing the grass 2, 6, or 12 cm from the cover-crop row. Placement of the ryegrass seed crop 6 cm from the cereal row showed that a significant yield increase of 34-71 kg ha-1 can be obtained compared with sowing in the cereal row....

  7. Energy-conserving perennial agriculture for marginal land in southern Appalachia. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, G.

    1982-01-30

    USDA economists predict the end of surplus farm production in the US within this decade. More and more marginal land will be cropped to provide feed for the growing world population and to produce energy. Much of this potential cropland in Southern Appalachia is poorly suited to annual crops, such as corn. Perennial crops are much better suited to steep, rocky, and wet sites. Research was undertaken on the theoretical potentials of perennial species with high predicted yields of protein, carbohydrates, or oils. Several candidate staple perennial crops for marginal land in Southern Appalachia were identified, and estimates were made of their yields, energy input requirements, and general suitabilities. Cropping systems incorporating honeylocust, persimmon, mulberry, jujube, and beech were compared with corn cropping systems. It appears that these candidate staple perennials show distinct advantages for energy conservation and environmental preservation. Detailed economic analyses must await actual demonstration trials, but preliminary indications for ethanol conversion systems with honeylocust are encouraging. It is suggested that short-term loans to farmers undertaking this new type of agriculture would be appropriate to solve cash-flow problems.

  8. Major Kansas Perennial Streams : 1961 and 2009

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Map of major perennial streams in Kansas for the years 1961 and 2009. The map shows a decrease in streams regarded as perennial in 1961, compared to stream regarded...

  9. Effects of Altered Weather Variables and Increased CO2 Concentrations on the Main Agricultural Crops of California's Central Valley Project

    Science.gov (United States)

    Flores-Lopez, F.; Young, C. A.; Tansey, M.; Yates, D.

    2010-12-01

    Potential changes in crop water demand and due to climate change is a growing concern among scientists and policy makers. In this study we analyze the potential response of evapotranspiration to climate change through the estimation of agricultural crops’ water use response to altered weather variables (temperature, precipitation, solar radiation, relative humidity, and wind speed) and an increased atmospheric CO2 concentration. Changes in growing season length, production of biomass and crop yields are also estimated through the use of downscaled climate futures selected to cover a wide range of the existing GCM results. An existing model, the Land, Air, and Water Simulator (LAWS) has been modified to include algorithms that account for the effects of altered weather variables, and the modeling of the top five agricultural crops in three representative regions of the California’s Central Valley Project System (Sacramento, San Joaquin river basin and the Delta area) is described. Study results show that atmospheric conditions can have complex and opposing influences on important evaluation metrics such as plant transpiration rates and cumulative water use, initiation and duration of the growing season, biomass production and crop yields. The magnitude of changes relative to historic conditions could be significant. Additional simulations are underway to expand the scope of the results throughout the California’s Central Valley Project System. These results will be directly relevant to the development of climate adaptation strategies effecting future Delta inflows.

  10. Native herbaceous perennials as ornamentals

    DEFF Research Database (Denmark)

    Larsen, Bjarne; Ørgaard, Marian

    2013-01-01

    Gardening with native perennials is a way to bring nature closer to urban citizens and bring up reflections on nature in a busy world. During three seasons of trialing Salvia pratensis, Dianthus deltoides, Campanula trachelium, Vincetoxicum hirundinaria, Saxifraga granulata, Plantago media and P....

  11. Estimated Perennial Streams in Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Perennial streams in Idaho have been modeled using regression equations for 7-day, 2-year low flows (7Q2) described in Wood and others (2009, U.S. Geological Survey...

  12. Freeze tolerance of perennial ryegrass

    Science.gov (United States)

    Perennial ryegrass is the most widely grown cool season grass in the world. Seed producers are developing more productive and more persistent varieties for North America. Different varieties exhibit a wide range of characteristics such as maturity, winter-hardiness, disease resistance, digestibility...

  13. The diversity of the N2O reducers matters for the N2O:N2 denitrification end-product ratio across an annual and a perennial cropping system.

    Directory of Open Access Journals (Sweden)

    Luiz eDomeignoz-Horta1

    2015-09-01

    Full Text Available Agriculture is the main source of terrestrial emissions of N2O, a potent greenhouse gas and the main cause of ozone layer depletion. The reduction of N2O into N2 by microorganisms carrying the nitrous oxide reductase gene (nosZ is the only biological process known to eliminate this greenhouse gas. Recent studies showed that a previously unknown clade of N2O-reducers was related to the capacity of the soil to act as an N2O sink, opening the way for new strategies to mitigate emissions. Here, we investigated whether the agricultural practices could differently influence the two N2O reducer clades with consequences for denitrification end-products. The abundance of N2O-reducers and producers was quantified by real-time PCR, and the diversity of both nosZ clades was determined by 454 pyrosequencing. Potential N2O production and potential denitrification activity were used to calculate the denitrification gaseous end-product ratio. Overall, the results showed limited differences between management practices but there were significant differences between cropping systems in both the abundance and structure of the nosZII community, as well as in the [rN2O/r(N2O+N2] ratio. More limited differences were observed in the nosZI community, suggesting that the newly identified nosZII clade is more sensitive than nosZI to environmental changes. Potential denitrification activity and potential N2O production were explained mainly by the soil properties while the diversity of the nosZII clade on its own explained 26% of the denitrification end-product ratio, which highlights the importance of understanding the ecology of this newly identified clade of N2O reducers for mitigation strategies.

  14. Landscape control of nitrous oxide emissions during the transition from conservation reserve program to perennial grasses for bioenergy

    Science.gov (United States)

    Debasish Saha; Benjamin M. Rau; Jason P. Kaye; Felipe Montes; Paul R. Adler; Armen R. Kemanian

    2016-01-01

    Future liquid fuel demand from renewable sources may, in part, be met by converting the seasonally wet portions of the landscape currently managed for soil and water conservation to perennial energy crops. However, this shift may increase nitrous oxide (N2O) emissions, thus limiting the carbon (C) benefits of energy crops. Particularly high emissions may occur during...

  15. Cumulative drought and land-use impacts on perennial vegetation across a North American dryland region

    Science.gov (United States)

    Munson, Seth M.; Long, A. Lexine; Wallace, Cynthia; Webb, Robert H.

    2016-01-01

    Question The decline and loss of perennial vegetation in dryland ecosystems due to global change pressures can alter ecosystem properties and initiate land degradation processes. We tracked changes of perennial vegetation using remote sensing to address the question of how prolonged drought and land-use intensification have affected perennial vegetation cover across a desert region in the early 21st century? Location Mojave Desert, southeastern California, southern Nevada, southwestern Utah and northwestern Arizona, USA. Methods We coupled the Moderate-Resolution Imaging Spectroradiometer Enhanced Vegetation Index (MODIS-EVI) with ground-based measurements of perennial vegetation cover taken in about 2000 and about 2010. Using the difference between these years, we determined perennial vegetation changes in the early 21st century and related these shifts to climate, soil and landscape properties, and patterns of land use. Results We found a good fit between MODIS-EVI and perennial vegetation cover (2000: R2 = 0.83 and 2010: R2 = 0.74). The southwestern, far southeastern and central Mojave Desert had large declines in perennial vegetation cover in the early 21st century, while the northeastern and southeastern portions of the desert had increases. These changes were explained by 10-yr precipitation anomalies, particularly in the cool season and during extreme dry or wet years. Areas heavily impacted by visitor use or wildfire lost perennial vegetation cover, and vegetation in protected areas increased to a greater degree than in unprotected areas. Conclusions We find that we can extrapolate previously documented declines of perennial plant cover to an entire desert, and demonstrate that prolonged water shortages coupled with land-use intensification create identifiable patterns of vegetation change in dryland regions.

  16. Use of Unmanned Aerial Vehicles for Improving Farm Scale Agricultural Water Management in Agriculture at a Farm Scale. A case study for field crops in the California's Central Valley

    Science.gov (United States)

    Medellin-Azuara, J.; Morande, J. A.; Jin, Y.; Chen, Y.; Paw U, K. T.; Viers, J. H.

    2016-12-01

    Traditional methods for estimating consumptive water use as evapotranspiration (ET) for agriculture in areas with water limitations such as California have always been a challenge for farmers, water managers, researchers and government agencies. Direct measurement of evapotranspiration (ET) and crop water stress in agriculture can be a cumbersome and costly task. Furthermore, spatial variability of applied water and irrigation and stress level in crops, due to inherent heterogeneity in soil conditions, topography, management practices, and lack of uniformity in water applications may affect estimates water use efficiency and water balances. This situation difficult long-term management of agroecosystems. This paper presents a case study for various areas in California's Central Valley using Unmanned Aerial Vehicles (UAVs) for a late portion of the 2016 irrigation season These estimates are compared those obtained by direct measurement (from previously deployed stations), and energy balance approaches with remotely sensed data in a selection of field crop parcels. This research improves information on water use and site conditions in agriculture by enhancing remote sensing-based estimations through the use of higher resolution multi-spectral and thermal imagery captured by UAV. We assess whether more frequent information at higher spatial resolution from UAVs can improve estimations of overall ET through energy balance and imagery. Stress levels and ET are characterized spatially to examine irrigation practices and their performance to improve water use in the agroecosystem. Ground based data such as air and crop temperature and stem water potential is collected to validate UAV aerial measurements. Preliminary results show the potential of UAV technology to improve timing, resolution and accuracy in the ET estimation and assessment of crop stress at a farm scales. Side to side comparison with ground level stations employing surface renewal, eddy covariance and

  17. Replacement names for two homonyms of Liothrips brevitubus Karny: one from California, the other for a species damaging Jatropha crops in Mexico.

    Science.gov (United States)

    Mound, Laurence; Goldarazena, Arturo; Lopez-Guillen, Guillermo; Hance, Thierry

    2016-12-21

    There are nearly 280 species of Liothrips listed from around the world (ThripsWiki 2016), all of them presumably feeding and breeding on the leaves of higher plants, and sometimes inducing or being associated with galls (Mound 1994). Despite this, for most of these species the identity of the plant species on which they are dependent is rarely known, and a particularly high proportion of the species are based on few specimens or even single individuals (cf Table 1). As a result, the identity of many of these named species continues to be in doubt. Modern identification keys are available only to the 23 Liothrips species known from Japan (Okajima 2006), the four European species known from Iran (Minaei & Mound 2014), and 14 species from Illinois (Stannard 1968). In contrast, the keys to 16 species of Liothrips from Brazil (Moulton 1933), to more than 80 species from Indonesia (Priesner 1968), and to 50 species from India (Ananthakrishnan & Sen 1980), are of little more than archival interest, in that they are based on few specimens with little allowance for intraspecific variation. Mound & Marullo (1996) listed over 80 Liothrips species from the Americas, although some of these are now placed in Pseudophilothrips (see Mound et al. 2010). That list included two homonyms of the Indonesian species Liothrips brevitubus Karny, one from Mexico and one from California. The homonym from Mexico is here recognised as applying to a species that in 2015 caused severe damage to a crop of Jatropha curcas in Chiapas. The objectives here are to provide a valid name for this pest, to facilitate its recognition among the 13 species of Liothrips recorded from Mexico (Table I), and also to replace the homonym from California.

  18. Nitrogen cycling in summer active perennial grass systems in South Australia: Non-symbiotic nitrogen fixation

    NARCIS (Netherlands)

    Gupta, V.V.S.R.; Kroker, S.J.; Hicks, M.; Davoren, W.; Descheemaeker, K.K.E.; Llewellyn, R.

    2014-01-01

    Non-symbiotic nitrogen (N2) fixation by diazotrophic bacteria is a potential source for biological N inputs in non-leguminous crops and pastures. Perennial grasses generally add larger quantities of above- and belowground plant residues to soil, and so can support higher levels of soil biological

  19. Genetic and environmental variation in a commercial breeding program of perennial ryegrass

    DEFF Research Database (Denmark)

    Fé, Dario; Pedersen, Morten Greve; Jensen, Christian S

    2015-01-01

    Implementation of genomic selection (GS) for the genetic improvement of forage crops, such as perennial ryegrass, requires the establishment of sufficiently large training populations ith high-quality phenotype and genotype data. This paper presents estimates of genetic and environmental variance...

  20. Path and correlation analysis of perennial ryegrass (Lolium perenne L.) seed yield components

    DEFF Research Database (Denmark)

    Abel, Simon; Gislum, René; Boelt, Birte

    2017-01-01

    Maximum perennial ryegrass seed production potential is substantially greater than harvested yields with harvested yields representing only 20% of calculated potential. Similar to wheat, maize and other agriculturally important crops, seed yield is highly dependent on a number of interacting seed...

  1. Anaerobic co-digestion of perennials: Methane potential and digestate nitrogen fertilizer value

    DEFF Research Database (Denmark)

    Muller-Stover, Dorette Sophie; Sun, Guotao; Kroff, Pablo

    2016-01-01

    Co-digestion of crop biomass improves the traditional manure-based biogas yield due to an increased content of easily degradable carbon compounds. In this study, the methane potential of three perennials (grass, legumes, and grass+legume) was determined using various amounts together with animal ...

  2. Biomassa microbiana e atividade enzimática em solos sob vegetação nativa e sistemas agrícolas anuais e perenes na região de Primavera do Leste (MT Microbial biomass and enzyme activities in soils under native vegetation and under annual and perennial cropping systems at the Primavera do Leste region - Mato Grosso State

    Directory of Open Access Journals (Sweden)

    M. Matsuoka

    2003-06-01

    microbial biomass and enzyme activities in soils under native vegetation (known as "Cerradão" and in soils under annual and perennial cropping systems. Soil samples were collected, at the beginning of the rainy season, at two depths (0-5 and 5-20 cm in areas under a vineyard (row and between rows, annual crops (soybean and native vegetation. The parameters evaluated were soil microbial biomass carbon (MBC, readily mineralizable carbon (microbial respiration and the soil enzymes beta-glucosidase, acid phosphatase and arylsulfatase. In relation to the native area, at the two depths reductions of up to 70% in the MBC were observed in the annual and perennial cropping systems. The soil management conducted in the area between the rows of the vineyard along with the presence of the grass Eleusine indica, as a cover crop, favored an increase in the levels of readily mineralizable carbon, and the beta-glucosidase and arilsulfatase activities. The P content of the soil under Cerradão, at the two depths, reduced the levels of acid phosphatase activities as compared to other places of the Cerrados region. Nevertheless, at the 0-5 cm depth the phosphatase activity of the Cerradão area was greater than in the annual crops, showing the importance of this enzyme on organic P cycling in native ecosystems. The results confirmed the sensibility of microbiological and biochemical parameters to evaluate changes that occurred in soil as a consequence of different management systems.

  3. Modeling the productivity of energy crops in different agro-ecological environments

    NARCIS (Netherlands)

    Jing, Q.; Conijn, J.G.; Jongschaap, R.E.E.; Bindraban, P.S.

    2012-01-01

    A relatively stable biomass productivity of perennial crop after plantation establishment makes it possible to calculate their total biomass yield through predicting the annual biomass yield. The generic model LINPAC (LINTUL model for Perennial and Annual Crops) is presented to predict annual

  4. Weed Flora and Dormant-season cover crops have no effects on arbuscular mycorrhizae of grapevine

    Science.gov (United States)

    We tested the hypotheses that mycorrhizal colonization of a perennial crop increases with a high frequency of mycorrhizal hosts within the plant community, and that a high diversity of mycorrhizal hosts is associated with a high diversity of arbuscular mycorrhizal fungi (AMF) on the perennial crop. ...

  5. The effect of perennials as green manure on cereal productivity and disease incidence

    Energy Technology Data Exchange (ETDEWEB)

    Skuodiene, R.; Nekrosiene, R.

    2012-11-01

    Field experiments were conducted at the Vezaiciai Branch of the Lithuanian Research Centre for Agriculture and Forestry during the period 2002-2007. They were designed to ascertain the effects of phytomass of different perennial pre-crops used for green manure on the productivity and on the occurrence of foliar fungal diseases of cereal agrocenoses. Plant residues and phytomass ploughed down as green manures positively affected cereal indices of crop productivity not only for the first but for the second year as well. It influenced the productivity of cereal segments. The largest amount of metabolizable energy was in the yield of cereal sequence under white clover (Trifolium repens L.) 83.23-84.76% GJ ha{sup 1}. The potential accumulated by perennials of the second year of development was more efficiently utilised by winter triticale (Triticosecale Wittm.) cv. Tevo, and that of perennials of the third year of development was more efficiently utilised by spring barley (Hordeum vulgare L.) cv. Ula. Perennials had a significant effect on the spread of foliar diseases in winter triticale (Triticosecale Wittm.) and spring barley (Hordeum vulgare L.) agrocenoses. The severity of the disease was 1.1-1.3 times higher in the winter triticale (Triticosecale Wittm.) treatments with white clover (Trifolium repens L.) pre-crops. Foliar disease incidence and severity was 1.1-1.2 times higher in the agrocenoses of spring barley (Hordeum vulgare L.) after legumes of the third year of development, especially after lucerne (Medicago sativa L.). (Author) 28 refs.

  6. N2O emissions from California farmlands: A review

    Directory of Open Access Journals (Sweden)

    Elizabeth Verhoeven

    2017-09-01

    Full Text Available Of the greenhouse gases emitted from cropland, nitrous oxide (N2O has the highest global warming potential. The state of California acknowledges that agriculture both contributes to and is affected by climate change, and in 2016 it adopted legislation to help growers reduce emissions of greenhouse gases, explicitly including N2O. Nitrous oxide emissions can vary widely due to environmental and agronomic factors with most emission estimates coming from temperate grain systems. There is, however, a dearth of emission estimates from perennial and vegetable cropping systems commonly found in California's Mediterranean climate. Therefore, emission factors (EFs specific to California conditions are needed to accurately assess statewide N2O emissions and mitigation options. In this paper, we review 16 studies reporting annual and seasonal N2O emissions. This data set represents all available studies on measured emissions at the whole field scale and on an event basis. Through this series of studies, we discuss how such farm management and environmental factors influence N2O emissions from California agriculture and may serve as a basis for improved EF calculations.

  7. Cover crops to improve soil health and pollinator habitat in nut orchards

    Science.gov (United States)

    Jerry. Van Sambeek

    2017-01-01

    Recently several national programs have been initiated calling for improving soil health and creating pollinator habitat using cover crops. Opportunities exist for nut growers to do both with the use of cover crops in our nut orchards. Because we can include perennial ground covers as cover crops, we have even more choices than landowners managing cover crops during...

  8. Genetic variation, population structure, and linkage disequilibrium in European elite germplasm of perennial ryegrass

    DEFF Research Database (Denmark)

    Brazauskas, Gintaras; Lenk, Ingo; Pedersen, Morten Greve

    2011-01-01

    Perennial ryegrass (Lolium perenne L.) is a highly valued temperate climate grass species grown as forage crop and for amenity uses. Due to its outbreeding nature and recent domestication, a high degree of genetic diversity is expected among cultivars. The aim of this study was to assess the extent...... of linkage disequilibrium (LD) within European elite germplasm and to evaluate the appropriate methodology for genetic association mapping in perennial ryegrass. A high level of genetic diversity was observed in a set of 380 perennial ryegrass elite genotypes when genotyped with 40 SSRs and 2 STS markers...... and occurred within 0.4 cM across European varieties, when population structure was taken into consideration. However, an extended LD of up to 6.6 cM was detected within the variety Aberdart. High genetic diversity and rapid LD decay provide means for high resolution association mapping in elite materials...

  9. The Perennial Ryegrass GenomeZipper – Targeted Use of Genome Resources for Comparative Grass Genomics

    DEFF Research Database (Denmark)

    Pfeiffer, Matthias; Martis, Mihaela; Asp, Torben

    2013-01-01

    Whole-genome sequences established for model and major crop species constitute a key resource for advanced genomic research. For outbreeding forage and turf grass species like ryegrasses (Lolium spp.), such resources have yet to be developed. Here, we present a model of the perennial ryegrass...... (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold...... to establish the chromosomal arrangement of syntenic genes from model grass species. This scaffold revealed a high degree of synteny and macrocollinearity and was then utilized to anchor a collection of perennial ryegrass genes in silico to their predicted genome positions. This resulted in the unambiguous...

  10. Life history and resource acquisition: Photosynthetic traits in selected accessions of three perennial cereal species compared with annual wheat and rye.

    Science.gov (United States)

    Jaikumar, Nikhil S; Snapp, Sieglinde S; Sharkey, Thomas D

    2013-12-01

    Few previous studies have considered how plant age affects photosynthetic physiology in herbaceous perennials or how photosynthetic capacity in annual cereals compares to perennial relatives. Newly developed perennial cereals offer novel systems for addressing these questions. Our study makes a novel contribution by considering how life history differences affect photosynthetic physiology. In two linked field studies, we evaluated effects of life history and plant age on photosynthetic rates (A), and related biochemical, morphological, and water-relations traits, comparing 1- and 2-yr-old cohorts of perennial wheat, intermediate wheatgrass, and perennial rye to close annual relatives (wheat and rye). Photosynthetic rates (A) were 10-50% higher in perennial cereals compared to annuals. In wheatgrass, elevated A was associated with higher carboxylation (VC), triose phosphate utilization (TPU) and electron transport rates (J), and higher leaf soluble protein and chlorophyll. Younger wheatgrass plants maintained higher A, TPU, J, and VC than older plants did. Perennial wheat and rye differed from annual relatives in some but not all of these parameters. Differences in stomatal limitation were not involved, while differences in stomatal conductance (gs) became evident under drier conditions. This study demonstrates that some perennial cereal species can maintain higher midseason A than their annual crop relatives. These changes are not fully explainable by increased access to soil water and may reflect trade-offs between allocation to reproduction and to resource acquisition. We also found evidence for age-related changes in photosynthetic physiology in a herbaceous perennial plant.

  11. Relative densities of natural enemy and pest insects within California hedgerows.

    Science.gov (United States)

    Gareau, Tara L Pisani; Letourneau, Deborah K; Shennan, Carol

    2013-08-01

    Research on hedgerow design for supporting communities of natural enemies for biological control lags behind farmer innovation in California, where assemblages of perennial plant species have been used on crop field margins in the last decade. We compared natural enemy to pest ratios between fields with hedgerows and fields with weedy margins by sampling beneficial insects and key pests of vegetables on sticky cards. We used biweekly vacuum samples to measure the distribution of key insect taxa among native perennial plant species with respect to the timing and intensity of bloom. Sticky cards indicated a trend that field margins with hedgerows support a higher ratio of natural enemies to pests compared with weedy borders. Hedgerow plant species hosted different relative densities of a generally overlapping insect community, and the timing and intensity of bloom only explained a small proportion of the variation in insect abundance at plant species and among hedgerows, with the exception of Orius spp. on Achillea millefolium L. and Baccharis pilularis De Candolle. Indicator Species Analysis showed an affinity of parasitic wasps, especially in the super-family Chalcidoidea, for B. pilularis whether or not it was in flower. A. millefolium was attractive to predatory and herbivorous homopterans; Heteromeles arbutifolia (Lindley) Roemer and B. pilularis to Diabrotica undecimpunctata undecimpunctata Mannerheim; and Rhamnus californica Eschsch to Hemerobiidae. Perennial hedgerows can be designed through species selection to support particular beneficial insect taxa, but plant resources beyond floral availability may be critical in providing structural refuges, alternative prey, and other attractive qualities that are often overlooked.

  12. Selection of crop cultivars suited to the location combined with astute management can reduce crop yield penalties in pasture cropping systems

    NARCIS (Netherlands)

    Thomass, D.R.; Lawes, R.A.; Descheemaeker, K.K.E.; Moore, A.D.

    2014-01-01

    Pasture cropping is an emerging farming-systems practice of southern Australia, in which winter grain crops are sown into an established stand of a winter-dormant, summer-growing perennial pasture. There is a pressing need to define times, locations and climates that are suitable for pasture

  13. Does soil C accrual under perennial grasses managed for bioenergy offset fertilizer induced N2O emission?

    Science.gov (United States)

    Perennial grasses (e.g., switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman) are often touted as being low input and as having a C-neutral foot print, but managing them as bioenergy feedstock means adding nitrogenous fertilizer or inter-cropping with legumes, which can i...

  14. 78 FR 21015 - Noninsured Crop Disaster Assistance Program

    Science.gov (United States)

    2013-04-09

    ... USDA. NAP coverage is not automatic; producers must apply for NAP and pay a service fee at their FSA... that inadequacy of irrigation as a condition for crops other than tree crops and perennials will be... precisely test the cause of loss and reflects current policy since the lack of irrigation could not have...

  15. Utilization of sunflower crop wild relatives for cultivated sunflower improvement

    Science.gov (United States)

    Sunflower (Helianthus annuus L.) is one of the few crops native to the U.S. The current USDA-ARS-NPGS crop wild relatives sunflower collection is the largest extant collection in the world, containing 2,519 accessions comprised of 53 species; 39 perennial and 14 annual. To fully utilize gene bank co...

  16. Using corngrass1 to engineer poplar as a bioenergy crop

    Energy Technology Data Exchange (ETDEWEB)

    Meilan, Richard; Rubinelli, Peter Marius; Chuck, George

    2016-05-10

    Embodiments of the present invention relate generally to new bioenergy crops and methods of creating new bioenergy crops. For example, genes encoding microRNAs (miRNAs) are used to create transgenic crops. In some embodiments, over-expression of miRNA is used to produce transgenic perennials, such as trees, with altered lignin content or composition. In some embodiments, the transgenic perennials are Populus spp. In some embodiments, the miRNA is a member of the miR156 family. In some embodiments, the gene is Zea mays Cg1.

  17. Spread dynamics of perennial pepperweed (Lepidium latifolium) in two seasonal wetland areas

    Science.gov (United States)

    Renz, Mark J.; Steinmaus, Scott J.; Gilmer, David S.; DiTomaso, Joseph M.

    2012-01-01

    Perennial pepperweed is an invasive plant that is expanding rapidly in several plant communities in the western United States. In California, perennial pepperweed has aggressively invaded seasonal wetlands, resulting in degradation of habitat quality. We evaluated the rate and dynamics of population spread, assessed the effect of disturbance on spread, and determined the biotic and abiotic factors influencing the likelihood of invasion. The study was conducted at eight sites within two wetland regions of California. Results indicate that in undisturbed sites, spread was almost exclusively through vegetative expansion, and the average rate of spread was 0.85 m yr−1 from the leading edge. Spread in sites that were disked was more than three times greater than in undisturbed sites. While smaller infestations increased at a faster rate compared with larger populations, larger infestations accumulated more newly infested areas than smaller infestations from year to year. Stem density was consistently higher in the center of the infestations, with about 2.4 times more stems per square meter compared with the leading edge at the perimeter of the population. The invasion by perennial pepperweed was positively correlated with increased water availability but was negatively correlated with the cover of perennial and annual species. Thus, high cover of resident vegetation can have a suppressive effect on the rate of invasion, even in wetland ecosystems. On the basis of these results, we recommend that resident plant cover not be disturbed, especially in wet areas adjacent to areas currently infested with perennial pepperweed. For infested areas, management efforts should be prioritized to focus on controlling satellite populations as well as the leading edge of larger infestations first. This strategy could reduce the need for costly active restoration efforts by maximizing the probability of successful re-establishment of resident vegetation from the adjacent seedbank.

  18. Comparative economic analysis of perennial, annual, and intercrops for biomass production

    Energy Technology Data Exchange (ETDEWEB)

    Hallam, A. [Iowa State University, Ames, IA (United States). Dept. of Economics; Anderson, I.C. [Iowa State University, Ames, IA (United States). Dept. of Agronomy; Buxton, D.R. [USDA-ARS-NPS, Beltsville, MD (United States)

    2001-12-01

    Herbaceous crops may be an important source of renewable energy. Production costs can be more competitive by increasing yields so that overhead costs are applied to more biomass. Most previous economic studies of energy crops have concentrated on the production of switchgrass (Panicum virgatum L.). This study analyzes the biomass yield and economic potential of several high-yielding annual and perennial crops on prime and marginal, sloping land. Crops evaluated were reed canarygrass (Phalaris arundinacea L.) harvested twice per year; switchgrass and big bluestem (Andropogon gerardii Vitman var. gerardii); alfalfa (Medicago sativa L.); and sweet sorghum, forage sorghum [both Sorghum bicolor (L.) Moench], and maize (Zea mays L.). The intercropping of the two sorghum species into reed canarygrass and alfalfa was also analyzed. All crops but alfalfa were fertilized with 0, 70, 140, or 280 kgNha{sup -1}, with economic analysis performed assuming 140 kgNha{sup -1}. Sorghums were most productive, with more than 16 t of dry matter ha{sup -1}. Switchgrass was the highest-yielding perennial crop. Costs per ton of biomass produced were lowest for sorghum, somewhat higher for switchgrass, higher still for big bluestem, and highest for alfalfa and reed canarygrass. Yields per ton for intercropped species were higher than for perennial species but lower than for monocrop sorghum. Costs per ton for intercropped species were less than for either alfalfa or reed canarygrass, but were higher than costs per ton of monocrop sorghum. Although the sorghums had the highest yields, high potential for erosion on sloping soils may preclude their use on these soils. (author)

  19. Dedicated energy crops and crop residues for bioenergy feedstocks in the Central and Eastern U.S.A.

    Science.gov (United States)

    Dedicated energy crops and crop residues will meet herbaceous feedstock demands for the new bioeconomy in the Central and Eastern USA. Perennial warm-season grasses and corn stover are well-suited to the eastern half of the USA and provide opportunities for expanding agricultural operations in the r...

  20. De novo Transcriptome Analysis in Perennial Ryegrass

    DEFF Research Database (Denmark)

    Farrell, Jacqueline Danielle; Byrne, Stephen; Asp, Torben

    Perennial ryegrass (Lolium perenne L.) is an important grass species for both forage and amenity purposes for temperate regions worldwide. It is envisaged that breeding efforts may be enhanced with the assistance of new breeding technologies such as genomic selection. A major step towards genomic...... of functional markers for improved ryegrass breeding. Therefore, the goal of this study is to analyze a de novo assembly of the perennial ryegrass transcriptome from the same inbred genotype being used for de novo genome assembly. Furthermore, we also conducted de novo transcriptome assembly with other...

  1. Exploring an Annotated Sequence Assembly of the Perennial Ryegrass Genome for Genomic Regions Enriched for Trait Associated Variants

    DEFF Research Database (Denmark)

    Byrne, Stephen; Cericola, Fabio; Janss, Luc

    2015-01-01

    Perennial ryegrass (Lolium perenne L.) is an outbreeding diploid species and one of the most important forage crops used in temperate agriculture. We have developed a draft sequence assembly of the perennial ryegrass genome and annotated it with the aid of RNA-seq data from various genotypes, plant...... components, and treatments. We predicted 39,795 high quality proteins originating from 28,182 genetic loci. We wanted to use the annotated assembly to study if SNPs falling within various annotation classes explain differing proportions of the variance for traits such as heading date and rust resistance...

  2. Estimativa da resistência mecânica à penetração de um latossolo vermelho sob cultura perene no norte do estado do Paraná Estimating penetration resistance of an oxisol under perennial crop in northern Paraná state

    Directory of Open Access Journals (Sweden)

    Adriana Aparecida Ribon

    2008-10-01

    concluir que as equações que melhor estimaram a resistência do solo à penetração foram: para Ug 0,30 kg kg-1: RPE = 3,20 - 13,78Ug + 4,43Ds (R² = 0,97. Em todas as situações estudadas, os coeficientes de variação variaram de altos (situação UG1 a muito altos (situação UG2 e Ug3, caracterizando alta variabilidade espacial da RP; logo, a utilização dos modelos selecionados deve ser feita com cautela, pois ocorre importante dispersão de pontos estimados por meio dos modelos, em relação aos valores medidos.Soil resistance to root penetration is an important physical characteristic for defining soil management techniques. The purpose of this study was to estimate the mechanical soil penetration resistance of an Oxisol under perennial crop, at three gravimetrical moisture contents, based on bulk density, moisture, and soil clay and organic matter content. The soil penetration resistance was evaluated by an impact penetrometer and the impact data in dm-1 were converted into dynamic resistance (MPa. At the moment of the determination of the mechanical soil resistance, samples (30 samples for each layer (0-0.10; 0.1-0.3; 0.3-0.5 m were collected to determine three different gravimetrical moisture contents (Ug (Ug1 0.30 kg kg-1 , clay texture (Arg, organic matter (MO and soil bulk density (Ds. Tests of normal distribution were applied to select the participant variables of the models by the W test. Thereafter, analyses of simple correlation between the variable and STEPWISE multiple regression analyses were performed. To fit the models an analysis was performed with four independent variables, represented by: X1 = Ug, X2 = Ds, X3 = MO, X4 = Arg and the dependent variable (y was represented by the soil penetration resistance (RP. After establishing the final models, the effects of multicollinearity were tested by VIF (Variance Increase Factor, where the VIF values 0.30 kg kg-1 :RPE = 3.20 - 13.78Ug + 4.43Ds (R² = 0.97, R = 0.98. In all studied situations the

  3. Bird Use of Imperial Valley Crops [ds427

    Data.gov (United States)

    California Department of Resources — Agriculture crops in the Imperial Valley of California provide valuable habitat for many resident and migratory birds and are a very important component of the...

  4. Dedicated biomass crops can enhance biodiversity in the arable landscape.

    Science.gov (United States)

    Haughton, Alison J; Bohan, David A; Clark, Suzanne J; Mallott, Mark D; Mallott, Victoria; Sage, Rufus; Karp, Angela

    2016-11-01

    Suggestions that novel, non-food, dedicated biomass crops used to produce bioenergy may provide opportunities to diversify and reinstate biodiversity in intensively managed farmland have not yet been fully tested at the landscape scale. Using two of the largest, currently available landscape-scale biodiversity data sets from arable and biomass bioenergy crops, we take a taxonomic and functional trait approach to quantify and contrast the consequences for biodiversity indicators of adopting dedicated biomass crops on land previously cultivated under annual, rotational arable cropping. The abundance and community compositions of biodiversity indicators in fields of break and cereal crops changed when planted with the dedicated biomass crops, miscanthus and short rotation coppiced (SRC) willow. Weed biomass was consistently greater in the two dedicated biomass crops than in cereals, and invertebrate abundance was similarly consistently higher than in break crops. Using canonical variates analysis, we identified distinct plant and invertebrate taxa and trait-based communities in miscanthus and SRC willows, whereas break and cereal crops tended to form a single, composite community. Seedbanks were shown to reflect the longer term effects of crop management. Our study suggests that miscanthus and SRC willows, and the management associated with perennial cropping, would support significant amounts of biodiversity when compared with annual arable crops. We recommend the strategic planting of these perennial, dedicated biomass crops in arable farmland to increase landscape heterogeneity and enhance ecosystem function, and simultaneously work towards striking a balance between energy and food security.

  5. Nitrate Leaching From Grain Maize After Different Tillage Methods and Long/Short Term Cover Cropping

    DEFF Research Database (Denmark)

    Hansen, Elly Møller

    trial initiated in 1968 on a coarse sandy soil. The previous trial included spring sown crops undersown (with or without) perennial ryegrass (Lolium perenne L.) as cover crop, two N-rates (90 and 120 kg N ha-1) and different tillage methods (shallow tillage and ploughing autumn or spring). With maize......, each previous long-term treatment with soil tillage and cover crop was sub-divided into two, one with perennial ryegrass as cover crop and one without cover crop. The maize was sown in 2009 and 2010 and fertilized with 140 kg N ha-1. The objectives were to determine the effects on leaching of i......) previous history of long-term cover cropping, ii) soil tillage methods, iii) N rates and iv) present short-term use of cover cropping in maize. Preliminary results from 2009 – 2011 suggest that leaching after a history of cover cropping tended to be higher than after no history of cover cropping...

  6. Supply and Effects of Specialty Crop Insurance

    OpenAIRE

    Ethan Ligon

    2011-01-01

    The federal government has developed a large number of programs to insure various "specialty crops" over the last two decades; a given program is peculiar to a particular county and crop. This development has been particularly notable in California, because of its size and the diversity of crops produced there. If the extension of federal crop insurance programs to cover fruit and vegetable production has affected either producer or consumer welfare, then we would expect to see this reflected...

  7. Toward Genomics-Based Breeding in C3 Cool-Season Perennial Grasses

    Science.gov (United States)

    Talukder, Shyamal K.; Saha, Malay C.

    2017-01-01

    Most important food and feed crops in the world belong to the C3 grass family. The future of food security is highly reliant on achieving genetic gains of those grasses. Conventional breeding methods have already reached a plateau for improving major crops. Genomics tools and resources have opened an avenue to explore genome-wide variability and make use of the variation for enhancing genetic gains in breeding programs. Major C3 annual cereal breeding programs are well equipped with genomic tools; however, genomic research of C3 cool-season perennial grasses is lagging behind. In this review, we discuss the currently available genomics tools and approaches useful for C3 cool-season perennial grass breeding. Along with a general review, we emphasize the discussion focusing on forage grasses that were considered orphan and have little or no genetic information available. Transcriptome sequencing and genotype-by-sequencing technology for genome-wide marker detection using next-generation sequencing (NGS) are very promising as genomics tools. Most C3 cool-season perennial grass members have no prior genetic information; thus NGS technology will enhance collinear study with other C3 model grasses like Brachypodium and rice. Transcriptomics data can be used for identification of functional genes and molecular markers, i.e., polymorphism markers and simple sequence repeats (SSRs). Genome-wide association study with NGS-based markers will facilitate marker identification for marker-assisted selection. With limited genetic information, genomic selection holds great promise to breeders for attaining maximum genetic gain of the cool-season C3 perennial grasses. Application of all these tools can ensure better genetic gains, reduce length of selection cycles, and facilitate cultivar development to meet the future demand for food and fodder. PMID:28798766

  8. Toward Genomics-Based Breeding in C3 Cool-Season Perennial Grasses

    Directory of Open Access Journals (Sweden)

    Shyamal K. Talukder

    2017-07-01

    Full Text Available Most important food and feed crops in the world belong to the C3 grass family. The future of food security is highly reliant on achieving genetic gains of those grasses. Conventional breeding methods have already reached a plateau for improving major crops. Genomics tools and resources have opened an avenue to explore genome-wide variability and make use of the variation for enhancing genetic gains in breeding programs. Major C3 annual cereal breeding programs are well equipped with genomic tools; however, genomic research of C3 cool-season perennial grasses is lagging behind. In this review, we discuss the currently available genomics tools and approaches useful for C3 cool-season perennial grass breeding. Along with a general review, we emphasize the discussion focusing on forage grasses that were considered orphan and have little or no genetic information available. Transcriptome sequencing and genotype-by-sequencing technology for genome-wide marker detection using next-generation sequencing (NGS are very promising as genomics tools. Most C3 cool-season perennial grass members have no prior genetic information; thus NGS technology will enhance collinear study with other C3 model grasses like Brachypodium and rice. Transcriptomics data can be used for identification of functional genes and molecular markers, i.e., polymorphism markers and simple sequence repeats (SSRs. Genome-wide association study with NGS-based markers will facilitate marker identification for marker-assisted selection. With limited genetic information, genomic selection holds great promise to breeders for attaining maximum genetic gain of the cool-season C3 perennial grasses. Application of all these tools can ensure better genetic gains, reduce length of selection cycles, and facilitate cultivar development to meet the future demand for food and fodder.

  9. Genetic markers for flowering in perennial ryegrass

    DEFF Research Database (Denmark)

    Paina, Cristiana; Byrne, Stephen; Andersen, Jeppe Reitan

    2011-01-01

    Perennial ryegrass (Lolium perenne L.) is the principal forage grass utilized in Danish agriculture and underpins the beef and dairy sectors. It is characterized as having high digestibility, high nutritional value, and high productivity during vegetative growth. However, at the reproductive growth...... stage there is a significant reduction in digestibility due to an increase in the stem to leaf ratio. Thus, the controlled inhibition or delay of flowering would result in a significant increase of forage quality. Traditional breeding programs have been successfully breeding new varieties of perennial...... ryegrass for decades. However, it can take more than ten years to develop a new variety and involves intensive phenotyping at all stages of selection. It is envisaged that with the aid of molecular markers, breeding programs can be accelerated and gains increased. Our goal is to develop and validate...

  10. Distinguishing Galactomyces citri-aurantii from G. geotrichum and characterizing population structure of the two postharvest sour rot pathogens of fruit crops in California.

    Science.gov (United States)

    McKay, A H; Förster, H; Adaskaveg, J E

    2012-05-01

    A growth assay in lemon juice and polymerase chain reaction amplifications using newly designed species-specific primers from endopolygalacturonase and β-tubulin genes rapidly differentiated isolates of the morphologically similar fruit sour rot pathogens Galactomyces citriaurantii and G. geotrichum. Isolates of both species were collected from agricultural soils and decaying fruit at locations within and outside California, including worldwide locations, and were used in population genetic studies based on amplified fragment length polymorphic (AFLP) DNA markers. For all four geographically defined subpopulations (three counties of California and locations outside California) among 97 isolates of G. citri-aurantii and for the two subpopulations (origin within or outside California) among 35 isolates of G. geotrichum, the proportion of polymorphic loci and haplotypic diversity was high. In total, 82 unique haplotypes were identified for G. citri-aurantii for the four subpopulations and, of these, 80 haplotypes were unique among subpopulations. For G. geotrichum, 25 unique haplotypes were identified among the two subpopulations and no haplotype was shared. Indices of genetic differences (F(ST)) between subpopulations within each species were all low (e.g., 0.038 for G. geotrichum and 0.085 to 0.226 for G. citriaurantii), indicating a low level of genetic differentiation. Following clone correction, mating type segregation ratios for G. citri-aurantii did not significantly (P > 0.1) deviate from a 1:1 ratio for all four subpopulations or the entire population. Tests of the index of association (I(A)) and parsimony tree-length permutation tests (PTLPT) supported a random mating structure for clone-corrected data for the Kern, Tulare, and Ventura County subpopulations and the null hypothesis of random mating could not be rejected. Additionally, PTLPT also supported random mating for the "outside of California" population. For G. geotrichum, random mating was only

  11. Soils determine early revegetation establishment with and without cover crops in northern mixed grass prairie after energy development

    Science.gov (United States)

    We measured rangeland health and perennial grass establishment in twelve interim reclamations as part of oil extraction activity. Sites at Ft. Berthold Indian Reservation in North Dakota were planted with two different perennial grass mixes, with and without an oat cover crop in late summer/fall of ...

  12. Biomass production on marginal lands - catalogue of bioenergy crops

    Science.gov (United States)

    Baumgarten, Wibke; Ivanina, Vadym; Hanzhenko, Oleksandr

    2017-04-01

    Marginal lands are the poorest type of land, with various limitations for traditional agriculture. However, they can be used for biomass production for bioenergy based on perennial plants or trees. The main advantage of biomass as an energy source compared to fossil fuels is the positive influence on the global carbon dioxide balance in the atmosphere. During combustion of biofuels, less carbon dioxide is emitted than is absorbed by plants during photosynthesis. Besides, 20 to 30 times less sulphur oxide and 3 to 4 times less ash is formed as compared with coal. Growing bioenergy crops creates additional workplaces in rural areas. Soil and climatic conditions of most European regions are suitable for growing perennial energy crops that are capable of rapid transforming solar energy into energy-intensive biomass. Selcted plants are not demanding for soil fertility, do not require a significant amount of fertilizers and pesticides and can be cultivated, therefore, also on unproductive lands of Europe. They prevent soil erosion, contribute to the preservation and improvement of agroecosystems and provide low-cost biomass. A catalogue of potential bioenergy plants was developed within the EU H2020 project SEEMLA including woody and perennial crops that are allowed to be grown in the territory of the EU and Ukraine. The catalogue lists high-productive woody and perennial crops that are not demanding to the conditions of growing and can guarantee stable high yields of high-energy-capacity biomass on marginal lands of various categories of marginality. Biomass of perennials plants and trees is composed of cellulose, hemicellulose and lignin, which are directly used to produce solid biofuels. Thanks to the well-developed root system of trees and perennial plants, they are better adapted to poor soils and do not require careful maintenance. Therefore, they can be grown on marginal lands. Particular C4 bioenergy crops are well adapted to a lack of moisture and high

  13. Effects of white clover (Trifolium repens L.) on plant and soil nitrogen and soil organic matter in mixtures with perennial ryegrass (Lolium perenne L.).

    NARCIS (Netherlands)

    Elgersma, A.

    1997-01-01

    To increase our insight into the above- and belowground N flows in grass and grass-clover swards relations between crop and soil parameters were studied in a cutting trial with perennial ryegrass (Lolium perenne) monocultures and ryegrass-white clover (Trifolium repens) mixtures. The effects of

  14. Predicting anthesis date of perennial ryegrass (Lolium perenne L.) with growing degree-days at heading

    DEFF Research Database (Denmark)

    Abel, Simon; Byrne, Stephen; Asp, Torben

    2017-01-01

    The agronomic significance of heading date in crop species is well documented; however, the date of anthesis is often less emphasized even though it has important applications for seed quality and yield. Moreover, the relationship between heading and anthesis is not well defined. We propose...... that growing degree-days to heading can be used as a good predictor of anthesis date. Using a broad range of 520 diploid perennial ryegrass accessions, anthesis was found to be highly correlated with growing degree-days to heading, and growing degree-days to heading could be used to predict anthesis date...

  15. Predicting seed yield in perennial ryegrass using repeated canopy reflectance measurements and PLSR

    DEFF Research Database (Denmark)

    Gislum, René; Deleuran, Lise Christina; Boelt, Birte

    2009-01-01

    Repeated canopy reflectance measurements together with partial least-squares regression (PLSR) were used to predict seed yield in perennial ryegrass (Lolium perenne L.). The measurements were performed during the spring and summer growing seasons of 2001 to 2003 in three field experiments...... with first year seed crops using three sowing rates and three spring nitrogen (N) application rates. PLSR models were developed for each year and showed correlation coefficients of 0.71, 0.76, and 0.92, respectively. Regression coefficients showed in these experiments that the optimum time for canopy...

  16. Estimated metabolizable energy yields of perennial and annual grass swards compared with those of spring barley and oat

    Directory of Open Access Journals (Sweden)

    O. NIEMELÄINEN

    2008-12-01

    Full Text Available The dry matter yields of cultivar trials (from 1976 to 1998 at 15 sites in Finland of perennial grass sward (meadow fescue (Festuca pratensis cv. Boris, annual grass sward (Italian ryegrass (Lolium multiflorum, cv. Barmultra and Mitos, spring barley (Hordeum vulgare cv. Otra, Arra, Arve and oat (Avena sativa cv. Veli were used to estimate metabolisable energy yields (MEY by using the feeds metabolisable energy concentration values (MJ/kg DM from ruminant feed tables. Harvest index (HI of barley and oat was set to 50%, and straw yields and whole crop cereal silage (WCCS yields were generated from grain yields accordingly. The MEY in the third year of perennial grass (81.4 GJ/ha was significantly lower than that in the first (90.0 GJ/ha and second years (90.7 GJ/ha. However, on average, the one to three year old perennial grass-swards had significantly higher MEY than the annual grass swards (87.7 vs. 83.3 GJ/ha, respectively. The MEYs of perennial and annual grass swards were substantially higher than the MEY of barley grain (52.7 GJ/ha and oat grain (47. 8 GJ/ha. When the total herbage of cereals, i.e. straw and grain, was used in the calculations, at a ME value of 6.0 MJ/ kg dry matter (DM for straw, the MEY of barley rose to 75.8 GJ/ha and that of oat to 72.6 GJ/ha. Additionally, the MEY of barley was estimated in the WCCS production situation by converting total herbage to MEY by using ME value 9.9 MJ/kg DM. The MEY of barley in the WCCS calculations was 77.4 GJ/ha, which was significantly lower than the MEY of annual and perennial grass swards. The MEY of barley was a 60%, b 86%, and c 88% of the average MEY of one to three year old perennial grass sward when the MEY of barley was calculated according to a grain, b grain + straw, and c whole crop cereal silage. Perennial grass sward was the most productive of the studied crops in metabolisable energy production for ruminants.

  17. Nurse crop

    Science.gov (United States)

    Wayne D. Shepperd; John R. Jones

    1985-01-01

    In forestry, a nurse crop generally is a crop of trees or shrubs that fosters the development of another tree species, usually by protecting the second species, during its youth, from frost, insolation, or wind (Ford-Robertson 1971). Aspen may be a nurse crop for shade-tolerant tree species that do not become established in full sunlight (e.g., Engelmann spruce)....

  18. Modelling critical NDVI curves in perennial ryegrass

    DEFF Research Database (Denmark)

    Gislum, R; Boelt, B

    2010-01-01

      The use of optical sensors to measure canopy reflectance and calculate crop index as e.g. normalized difference vegetation index (NDVI) is widely used in agricultural crops, but has so far not been implemented in herbage seed production. The present study has the purpose to develop a critical N...

  19. 7 CFR 981.19 - Crop year.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Crop year. 981.19 Section 981.19 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE ALMONDS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 981.19 Crop yea...

  20. 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...

  1. 7 CFR 457.153 - Peach crop insurance provisions.

    Science.gov (United States)

    2010-01-01

    ... effect of interplanting a perennial crop; removal or addition of trees or varieties of trees; physical or... were set out; (2) Are a variety having a chilling hour requirement that is appropriate for the area; (3... chilling hours to effectively break dormancy; or (9) Failure of irrigation water supply, if caused by an...

  2. Nitrogen accumulation and residual effects of nitrogen catch crops

    DEFF Research Database (Denmark)

    Jensen, E.S.

    1991-01-01

    The nitrogen accumulation in Italian ryegrass (Lolium multiflorum Lam.), perennial ryegrass (Lolium perenne L.), white mustard (Sinapis alba L.) and tansy phacelia (Phacelia tanacetifolia L.), under- or aftersown as nitrogen catch crops to spring barley (Hordeum vulgare L.) and field pea (Pisum s...

  3. Selectivity of Some Herbicides to Perennial ryegrass (Lolium perenne L., Grown for Seed Production

    Directory of Open Access Journals (Sweden)

    Tsvetanka Dimitrova

    2011-01-01

    Full Text Available During the period 2008-2010, on the experimental field of the Institute of Forage Crops – Pleven, on slightly leached chernozem a study was conducted with the purpose to determine the selectivity of some herbicides to perennial ryegrass (Lolium perenne L., and theirinfluence on the seed productivity. As a result of the study the following was found: herbicides for broadleaf weeds control – Arat (500 g/l dicamba + 250 g/l tritosulfuron at rate of 100 ml/ha, Korida 75 VDG (750 g/kg tribenuron-methyl – 15 g/ha and Cambio SL (320 g/l bentazone + 90 g/l dicamba – 1250 ml/ha had high selectivity to perennial ryegrass, applied at 2-4 leaf stage during establishing year of the stand and until the stage of the beginning of shooting up in seed production year. Herbicide for grass weeds control: Topik 080EK (80 g/l clodinafop-prop-argyl + antidote at rate of 300 ml/ha, applied at the same stage can be applied in seed production stands of perennial ryegrass. Herbicide for grass weeds control – Grasp 25SK (250 g/l tralkoxydim + Atplus 463 at rate of 1000 + 1000 ml/ha showed phytotoxic effect on L. perenne and caused the reduction of seed and dry biomass productivity. Realization of the biological potential concerning seed and dry mass yield of perennial ryegrass demands application of selective herbicides Arat, Korida 75 VDG and Cambio SL in control of broadleaf weeds and Topik 080EK in control of grass weeds.

  4. Biomass productivity and radiation utilisation of innovative cropping systems for biorefinery

    DEFF Research Database (Denmark)

    Manevski, Kiril; Lærke, Poul Erik; Jiao, Xiurong

    2017-01-01

    In order to supply future biorefineries there is a need to sustainably intensify the biomass production on current agricultural land. The aim of this work was to determine biomass yield and associated radiation utilisation for novel perennial grasses and annual crops in rotations optimised...... on biodiversity. The fraction of intercepted photosynthetically active radiation (fIpar), the accumulated intercepted photosynthetically active radiation (Ipar) and the radiation use efficiency (RUE) were determined from canopy radiations measured biweekly for three years. These results showed a higher annual...... conditions. The lower aboveground RUE of perennial crops than of annual crops indicates differences in photosynthesis efficiencies and partitioning of assimilates to non-harvested plant parts and calls for further breeding of the perennial crops to improve their RUE....

  5. On the use of L-band multipolarization airborne SAR for surveys of crops, vineyards, and orchards in a California irrigated agricultural region

    Science.gov (United States)

    Paris, J. F.

    1985-01-01

    The airborne L-band synthetic aperture radar (SAR) collected multipolarization calibrated image data over an irrigated agricultural test site near Fresno, CA, on March 6, 1984. The conclusions of the study are as follows: (1) the effects of incidence angle on the measured backscattering coefficients could be removed by using a correction factor equal to the secant of the angle raised to the 1.4 power, (2) for this scene and time of year, the various polarization channels were highly correlated such that the use of more than one polarization added little to the ability of the radar to discriminate vegetation type or condition; the exception was barley which separated from vineyards only when a combination of like and cross polarization data were used (polarization was very useful for corn identification in fall crops), (3) an excellent separation between herbaceous vegetation (alfalfa, barley, and oats) or bare fields and trees in orchards existed in brightness was well correlated to alfalfa height or biomass, especially for the HH polarization combination, (5) vineyards exhibited a narrow range of brightnesses with no systematic effects of type or number of stakes nor of number of wires in the trellises nor of the size of the vines, (6) within the orchard classes, areal biomass characterized by basal area differences caused radar image brightness differences for small to medium trees but not for medium to large trees.

  6. Effects of different doses of organic fertilizer type bocashi in morphological and productive indicators of pepper crop (Capsicum annuum L. var. California wonder

    Directory of Open Access Journals (Sweden)

    Ana Boudet Antomarchi

    2015-04-01

    Full Text Available Between June and September 2012 in field condition in agroecological farm was carried out an investigation using a randomised block experimental design with four treatments and four repetitions with the objective to evaluate the effect of different doses of organic fertilizer bocashi in pepper crop (Capsicum annuum L..The treatment consisted in the application of different doses of organic fertilizer bocashi (1.66, 2.22, 2.78 tha-1 and a control treatment without application. The results were evaluated by means of the pro-gram Statistica version 8.0, for windows, where the indicators used showed significant differences multiple comparison of Tukey was applied to p ≤ 0.05. The variable evaluated were: height of the plants (cm, steam diameter (cm,yield and their components (number fruit.plant -1, average weigh of fruit (g, average diameter of fruit (cm and average large of fruit (cm. The treatment where was applied doses of 2.22 and 2.78 tha-1 of organic fertilizer bocashi was obtained the best results in productive indicator evaluated with securities in the agricultural yield of 33.4 and 32.9 tha-1

  7. Determination of microbial protein in perennial ryegrass silage

    NARCIS (Netherlands)

    Driehuis, F.; Wikselaar, van P.G.

    2001-01-01

    The microbial matter fraction was determined in perennial ryegrass silages of different dry-matter (DM) contents, ensiled with or without Lactobacillus plantarum. 15N-Leucine and the bacterial cell wall constituent diaminopimelic acid (DAPA) were used as markers for microbial-N. Perennial ryegrass

  8. Hydrologic properties of grazed perennial swards in semiarid ...

    African Journals Online (AJOL)

    The hypothesis was tested that grazed perennial swards have similar hydrologic properties and threshold removal levels below which runoff increases markedly. Infiltration capacity for the perennial swards increased with increasing stubble height before leveling off towards the highest stubble height. A 50% removal of ...

  9. The use of goat grazing to biologically suppress perennial pepperweed

    Science.gov (United States)

    Perennial pepperweed (Lepidium latifolium) is a creeping rooted exotic weed that has infested riparian areas, native hay meadows and agronomic fields throughout the western United States. Perennial pepperweed is a highly invasive weed that causes management and economic problems through the loss of...

  10. The genome and transcriptome of perennial ryegrass mitochondria

    DEFF Research Database (Denmark)

    Islam, Md. Shofiqul; Studer, Bruno; Byrne, Stephen

    2013-01-01

    Background: Perennial ryegrass (Lolium perenne L.) is one of the most important forage and turf grass species of temperate regions worldwide. Its mitochondrial genome is inherited maternally and contains genes that can influence traits of agricultural importance. Moreover, the DNA sequence...... and annotation of the complete mitochondrial genome from perennial ryegrass. Results: Intact mitochondria from perennial ryegrass leaves were isolated and used for mtDNA extraction. The mitochondrial genome was sequenced to a 167-fold coverage using the Roche 454 GS-FLX Titanium platform, and assembled...... of the mitochondrial genome from perennial ryegrass presented here constitutes an important tool for future attempts to compare mitochondrial genomes within and between grass species. Our results also demonstrate that mitochondria of perennial ryegrass contain genes crucial for energy production that are well...

  11. Anther culture of some perennial triticeae.

    Science.gov (United States)

    Marburger, J E; Wang, R R

    1988-08-01

    Three field grown Agropyron spp. (crested wheatgrasses) and two Thinopyrum spp. (intermediate and tall wheatgrasses) were evaluated for anther culture response. Hormonally modified potato extract and 85D12 media induced pollen embryogenesis. Modified Murashige and Skoog media were tested for their effects on callus proliferation and plantlet regeneration. Callus induction frequency and plantlet production were highest (25.0% and 45.8%, respectively) for Thinopyrum ponticum (2N=70) (tall wheatgrass). One-hundred and nine albino plantlets were produced from T. ponticum 'Jose' both by direct regeneration on 85D12 medium and through a callus phase from potato extract media. This is the first report of plantlet production from anther culture of a Triticeae perennial forage grass. Further experimentation with environmental and cultural conditions may result in the production of green plantlets.

  12. Hydrological responses of land use change from cotton (Gossypium hirsutum L.) to cellulosic bioenergy crops in the Southern High Plains of Texas, USA

    National Research Council Canada - National Science Library

    Chen, Yong; Ale, Srinivasulu; Rajan, Nithya; Morgan, Cristine L. S; Park, Jongyoon

    2016-01-01

    The Southern High Plains ( SHP ) region of Texas in the United States, where cotton is grown in a vast acreage, has the potential to grow cellulosic bioenergy crops such as perennial grasses and biomass sorghum ( Sorghum bicolor...

  13. Isolation and characterization of feruloylated arabinoxylan oligosaccharides from the perennial cereal grain intermediate wheat grass (Thinopyrum intermedium).

    Science.gov (United States)

    Schendel, Rachel R; Becker, Andreas; Tyl, Catrin E; Bunzel, Mirko

    2015-04-30

    In comparison to the annual grain crops dominating current agricultural production, perennial grain species require fewer chemical and energy inputs and improve soil health and erosion control. The possibility for producing sustainable grain harvests from marginal land areas is motivating research initiatives to integrate perennial grains into commercial cropping and food processing systems. In this study, the feruloylated arabinoxylans from intermediate wheat grass (Thinopyrum intermedium, IWG), a promising perennial grain candidate in agronomic screening studies, were investigated. Insoluble fiber isolated from IWG whole grain flour was subjected to either mildly acidic (50 mM TFA, 100 °C, 2 h) or enzymatic (Driselase) hydrolysis. The liberated feruloylated arabinoxylan oligosaccharides were concentrated with Amberlite XAD-2, separated with gel chromatography (Sephadex LH-20, water), and purified with reversed-phase HPLC (C18, water-MeOH gradient). Thirteen feruloylated oligosaccharides were isolated (including eight structures described for the first time) and identified by LC-ESI-MS and NMR. Linkage-type analysis via methylation analysis, as well as the monosaccharide and phenolic acid profiles of the IWG insoluble fiber were also determined. IWG feruloylated arabinoxylans have a relatively simple structure with only short feruloylated side chains, a lower backbone substitution rate than annual rye and wheat varieties, and a moderate phenolic acid content. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. 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.

  15. From berries to blocks: carbon stock quantification of a California vineyard.

    Science.gov (United States)

    Morandé, Jorge Andres; Stockert, Christine M; Liles, Garrett C; Williams, John N; Smart, David R; Viers, Joshua H

    2017-12-01

    Quantifying terrestrial carbon (C) stocks in vineyards represents an important opportunity for estimating C sequestration in perennial cropping systems. Considering 7.2 M ha are dedicated to winegrape production globally, the potential for annual C capture and storage in this crop is of interest to mitigate greenhouse gas emissions. In this study, we used destructive sampling to measure C stocks in the woody biomass of 15-year-old Cabernet Sauvignon vines from a vineyard in California's northern San Joaquin Valley. We characterize C stocks in terms of allometric variation between biomass fractions of roots, aboveground wood, canes, leaves and fruits, and then test correlations between easy-to-measure variables such as trunk diameter, pruning weights and harvest weight to vine biomass fractions. Carbon stocks at the vineyard block scale were validated from biomass mounds generated during vineyard removal. Total vine C was estimated at 12.3 Mg C ha-1, of which 8.9 Mg C ha-1 came from perennial vine biomass. Annual biomass was estimated at 1.7 Mg C ha-1 from leaves and canes and 1.7 Mg C ha-1 from fruit. Strong, positive correlations were found between the diameter of the trunk and overall woody C stocks (R2 = 0.85), pruning weights and leaf and fruit C stocks (R2 = 0.93), and between fruit weight and annual C stocks (R2 = 0.96). Vineyard C partitioning obtained in this study provides detailed C storage estimations in order to understand the spatial and temporal distribution of winegrape C. Allometric equations based on simple and practical biomass and biometric measurements could enable winegrape growers to more easily estimate existing and future C stocks by scaling up from berries and vines to vineyard blocks.

  16. Irrigation Strategies and Crop Breeding As Complementary Measures for Improved Water Management and Ecosystem Services

    Science.gov (United States)

    Vico, G.; Manzoni, S.; Weih, M.; Porporato, A. M.

    2014-12-01

    The projected population growth and changes in climate and dietary habits will further increase the pressure on water resources globally. Within precision farming, a host of technical solutions has been developed to reduce water consumption for agricultural uses. Examples are the shift from scheduled to demand-based irrigation and the use of sophisticated water distribution techniques. The next frontier for a more sustainable agriculture is the combination of reduced water requirements with enhanced ecosystem services. Currently, staple grains are obtained from annuals crops. Enhanced ecosystem services could be obtained shifting from annual to perennial crops, obtained by means of targeted breeding. In fact, perennial plants, with their continuous soil cover and the higher allocation of resources to the below ground, contribute to the reduction of soil erosion, water and nutrient losses, while enhancing carbon sequestration in the root zone. We explore here the implications for water management at the field- to farm-scale of both improved irrigation methods and targeted breeding. A probabilistic description of the soil water balance and crop development is employed to quantify water requirements and yields and their inter-annual variability, as a function of rainfall patterns, soil and crop features. Optimal irrigation strategies are thus defined in terms of maximization of yield and minimization of required irrigation volumes and their inter-annual variability. The probabilistic model is parameterized based on an extensive meta-analysis of traits of co-generic annual and perennial species (including both selected and wild species) to explore the consequences for water requirements of shifting from annual to perennial crops under current and future climates. The larger and more developed roots of perennial crops may allow a better exploitation of soil water resources than annual species. At the same time, perennial crops may require adequate water supply for

  17. California Bioregions

    Data.gov (United States)

    California Department of Resources — California regions developed by the Inter-agency Natural Areas Coordinating Committee (INACC) were digitized from a 1:1,200,000 California Department of Fish and...

  18. The potential of Cynara cardunculus L. for seed oil production in a perennial cultivation system

    Energy Technology Data Exchange (ETDEWEB)

    Curt, M.D.; Sanchez, G.; Fernandez, J. [Universidad Politecnica de Madrid, Dept. de Produccion Vegetal: Botanica y Proteccion Vegetal, Madrid (Spain)

    2002-07-01

    Cynara cardunculus L. has been recognised as an energy crop for rainfed lands with Mediterranean climates. For energy purposes, it is grown as a permanent crop and the whole aerial biomass produced over the annual growth cycle is harvested every year. In this work, the potential of C. cardunculus L. as an oil crop is studied in a perennial cultivation system. The degree of variation of seed oil content and fatty acid oil composition is assessed in two experiments designed to study the effect of the factors: plant population, crop year and experiment location. The range of values of seed oil content was greater for the multilocal experiment (20.0-31.6%) than for the experiment on populations (22.0-28.8%), but the effect of the agricultural year was noticed in both experiments. There were significant differences in the 18 populations experiment and a group of 5 populations was identified as rich in seed oil (>26%). Seed presscake was analysed and as a result the use of this material as fertiliser or as animal feed was proposed. Finally, the degree of variation of fatty acid oil composition-studied for the factors population, location and year-turned out to be rather small. Cynara oil profile was characterised in terms of major fatty acids as: 10.7% palmitic, 3.7% stearic, 25.0% oleic and 59.7% linoleic. (Author)

  19. Perennial Polyculture Farming: Seeds of Another Agricultural Revolution?

    National Research Council Canada - National Science Library

    Dewar, James A

    2007-01-01

    James Dewar presents arguments in favor of perennial polyculture farming as a positive contribution to a wide variety of global problems and suggests actions that should be taken to explore that promise further...

  20. A transcriptome map of perennial ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Studer, Bruno; Byrne, Stephen; Nielsen, Rasmus Ory

    2012-01-01

    -assisted breeding, a surprisingly low number of validated SNPs are currently available for perennial ryegrass. Results A perennial ryegrass unigene set representing 9,399 genes was used as a reference for the assembly of 802,156 high quality reads generated by 454 transcriptome sequencing and for in silico SNP...... discovery. Out of more than 15,433 SNPs in 1,778 unigenes fulfilling highly stringent assembly and detection parameters, a total of 768 SNP markers were selected for GoldenGate genotyping in 184 individuals of the perennial ryegrass mapping population VrnA, a population being previously evaluated...... a total of 838 DNA markers (767 gene-derived markers) and spans 750 centi Mogan (cM) with an average marker interval distance of less than 0.9 cM. Moreover, it locates 732 expressed genes involved in a broad range of molecular functions of different biological processes in the perennial ryegrass genome...

  1. Native prairie filter strips reduce runoff from hillslopes under annual row-crop systems in Iowa, USA

    Science.gov (United States)

    V. Hernandez-Santana; X. Zhou; M.J. Helmers; H. Asbjornsen; R. Kolka; M. Tomer

    2013-01-01

    Intensively managed annual cropping systems have produced high crop yields but have often produced significant ecosystem services alteration, in particular hydrologic regulation loss. Reconversion of annual agricultural systems to perennial vegetation can lead to hydrologic function restoration, but its effect is still not well understood. Therefore, our objective was...

  2. Eastern cottonwood and black willow biomass crop production in the Lower Mississippi Alluvial Valley under four planting densities

    Science.gov (United States)

    Ray A. Souter; Emile S Gardiner; Theodor D. Leininger; Dana Mitchell; Robert B. Rummer

    2015-01-01

    "Wood is an obvious alternative energy source": Johnson and others (2007) declare the potential of short-rotation intensively-managed woody crop systems to produce biomass for energy. While obvious as an energy source, costs of production need to be measured to assess the economic viability of selected tree species as woody perennial energy crops

  3. Nitrogen migration in crop rotations differing in fertilisation

    Energy Technology Data Exchange (ETDEWEB)

    Guzys, S.; Miseviciene, S.

    2015-07-01

    Inappropriate use of nitrogen fertilisers is becoming a global problem; however, continuous fertilisation with N fertiliser ensures large and constant harvests. To evaluate the relationships of differently fertilised cultivated plant rotation with N metabolism in the agroecosystem the research was conducted between 2006 and 2013 at Lipliūnai, Lithuania, in fields with calcareous gley brown soil, i.e. Endocalcari Endohypogleyic Cambisol (CMg-n-w-can). The research area covered three drained plots where crop rotation of differently fertilised cereals and perennial grasses were applied. The greatest productivity was found in a higher fertilisation (TII, 843 kg N/ha) cereals crop rotation. With less fertilisation (TI, 540 kg N/ha) crop rotation productivity of cereals and perennial grasses (TIII, 218 kg N/ha) was 11-35% lower. The highest amount of mineral soil N (average 76 kg/ha) was found in TI. It was influenced by fertilisation (r=0.71) and crop productivity (r=0.39). TIII tended to reduce Nmin (12.1 mg/L) and Ntotal (12.8 mg/L) concentrations in drainage water and leaching of these elements (7 and 8 kg/ha). Nmin and Ntotal concentrations in the water depended on crop productivity respectively (r=0.48; r=0.36), quantity of mineral soil N (r=0.65; r=0.59), fertilisation (r=0.59; r=0.52), and N balance (r=0.26; r=0.35). Cereal crop rotation increased N leaching by 12-42%. The use of all crop rotations resulted in a negative N balance. Nitrogen balance depended on fertilisation with N fertiliser (r=0.55). The application of perennial grasses crop rotation in agricultural fields was the best environmental tool, reducing N migration to drainage. (Author)

  4. THE OCCURRENCE OF ENTOMOPATHOGENIC FUNGI IN SOILS FROM CULTIVATED PERENNIAL RYEGRASS (LOLIUM PERENNE L.

    Directory of Open Access Journals (Sweden)

    Roman Kolczarek

    2014-12-01

    Full Text Available An important role in the agricultural agrocenosis is attributed to entomopathogenic fungi. They limit the occurrence of certain populations of soil pests and insects overwintering in the soil environment, or held in the pupation. Fungi are the only pathogens of arthropods witch have the ability to infect plant pests directly by body. However, bacteria are the largest group of microorganisms inhabiting the soil. The aim of this study was to compare the species composition and the severity of the occurrence of entomopathogenic fungi in soils of monoculture crops perennial ryegrass (Lolium perenne L.. The material consisted of soil samples taken from the experimental research conducted in two experimental stations of the Central Research Centre for Cultivar. The fungi isolated from soil insecticides using a method developed by the selective medium.

  5. Susceptibility to Rust (Puccinia Sp. in Cultivars of Italian and Perennial Ryegrass Grown in Two Locations of Italy

    Directory of Open Access Journals (Sweden)

    Luigi Russi

    2009-03-01

    Full Text Available A large set of foreign varieties of Italian ryegrass (Lolium multiflorum and perennial ryegrass (L. perenne were evaluated for their response to natural rust infection in two Italian locations (Lodi in the north; Perugia in the centre of the country at three-year intervals in 2001, 2004 and 2007, to acquire information on novel germplasm for Italy and verify any spatial and temporal variation in the varietal response to the disease. Crown rust (caused by Puccinia coronata on Italian ryegrass and stem rust (caused by P. graminis on perennial rygrass were consistently recorded in appreciable amount (average susceptibility score > 2.0 on a 1-9 scale. Vice-versa, crown rust on perennial and stem rust on Italian ryegrass seldom affected appreciably the crop. Strong interactions of variety response (to the prevailing pathogen with locations and years of evaluation were observed in both ryegrasses. Subsequently, the repeatability of results between locations, or between years within locations, as measured by rank correlations of variety scores, was sometimes only moderate or low. However, despite such interactions, a few promising varieties were identified in each species with consistently low susceptibility across evaluation environments, which deserve further investigation for a possible direct utilisation, or as donors of useful genes for breeding purposes.

  6. Seasonal versus perennial immunotherapy: evaluation after three years of treatment.

    Science.gov (United States)

    Muñoz Lejarazu, D; Bernaola, G; Fernández, E; Audícana, M; Ventas, P; Martín, S; Fernández de Corres, L

    1993-01-01

    We have performed a comparative study to evaluate seasonal and perennial schedules after 3 years of immunotherapy. Sixty patients suffering from rhinitis and/or asthma due to grass pollen sensitization were randomly allocated to receive a semi-depot extract of Phleum pratense according to a perennial or seasonal schedule. The last year of the study, 14 patients were recruited as a control group without immunotherapy. The cumulative dose was 602 BU in the perennial group and 372 BU in the seasonal group. The frequency and severity of side-effects were similar and very low in both treated groups. The IgE level was significantly lower after perennial immunotherapy at the end of the first 2 years. A seasonal decrease in specific IgG levels was observed in patients who interrupted immunotherapy, while this was not observed in patients under the perennial schedule. Symptoms and medication scores did not show differences between groups. Nevertheless, we found a significant difference between treated patients and the control group.

  7. Perennial Roots to Immortality1,2[C

    Science.gov (United States)

    Munné-Bosch, Sergi

    2014-01-01

    Maximum lifespan greatly varies among species, and it is not strictly determined; it can change with species evolution. Clonal growth is a major factor governing maximum lifespan. In the plant kingdom, the maximum lifespans described for clonal and nonclonal plants vary by an order of magnitude, with 43,600 and 5,062 years for Lomatia tasmanica and Pinus longaeva, respectively. Nonclonal perennial plants (those plants exclusively using sexual reproduction) also present a huge diversity in maximum lifespans (from a few to thousands of years) and even more interestingly, contrasting differences in aging patterns. Some plants show a clear physiological deterioration with aging, whereas others do not. Indeed, some plants can even improve their physiological performance as they age (a phenomenon called negative senescence). This diversity in aging patterns responds to species-specific life history traits and mechanisms evolved by each species to adapt to its habitat. Particularities of roots in perennial plants, such as meristem indeterminacy, modular growth, stress resistance, and patterns of senescence, are crucial in establishing perenniality and understanding adaptation of perennial plants to their habitats. Here, the key role of roots for perennial plant longevity will be discussed, taking into account current knowledge and highlighting additional aspects that still require investigation. PMID:24563283

  8. Rates of photosynthesis and transpiration of spring wheat and barley as influenced by fodder precrops and their cropping period

    OpenAIRE

    Küpper, Paul Martin; Perkons, Ute; Pries, Charlotte; Antar, Philipp Martin; KAUTZ, Timo; Köpke, Ulrich

    2014-01-01

    Perennial fodder cropping as compared to rotations including annual ploughing can increase the number of medium and large sized biopores in the subsoil. This can result in potentially facilitated root growth followed by increased accessibility of water in the subsoil. Additional plant-available water can enable stands to cope with dry periods in early summer, which will take place more often in future due to climate change. In this context we investigated whether crop species or cropping peri...

  9. Validation of reference genes for quantitative RT-PCR studies of gene expression in perennial ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Thrush Anthony

    2010-01-01

    Full Text Available Abstract Background Perennial ryegrass (Lolium perenne L. is an important pasture and turf crop. Biotechniques such as gene expression studies are being employed to improve traits in this temperate grass. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR is among the best methods available for determining changes in gene expression. Before analysis of target gene expression, it is essential to select an appropriate normalisation strategy to control for non-specific variation between samples. Reference genes that have stable expression at different biological and physiological states can be effectively used for normalisation; however, their expression stability must be validated before use. Results Existing Serial Analysis of Gene Expression data were queried to identify six moderately expressed genes that had relatively stable gene expression throughout the year. These six candidate reference genes (eukaryotic elongation factor 1 alpha, eEF1A; TAT-binding protein homolog 1, TBP-1; eukaryotic translation initiation factor 4 alpha, eIF4A; YT521-B-like protein family protein, YT521-B; histone 3, H3; ubiquitin-conjugating enzyme, E2 were validated for qRT-PCR normalisation in 442 diverse perennial ryegrass (Lolium perenne L. samples sourced from field- and laboratory-grown plants under a wide range of experimental conditions. Eukaryotic EF1A is encoded by members of a multigene family exhibiting differential expression and necessitated the expression analysis of different eEF1A encoding genes; a highly expressed eEF1A (h, a moderately, but stably expressed eEF1A (s, and combined expression of multigene eEF1A (m. NormFinder identified eEF1A (s and YT521-B as the best combination of two genes for normalisation of gene expression data in perennial ryegrass following different defoliation management in the field. Conclusions This study is unique in the magnitude of samples tested with the inclusion of numerous field-grown samples

  10. Perennial grasses as lignocellulosic feedstock for second-generation bioethanol production in Mediterranean environment

    Directory of Open Access Journals (Sweden)

    Danilo Scordia

    2014-06-01

    Full Text Available In this paper the suitability of three perennial, herbaceous, lignocellulosic grasses (Arundo donax, Saccharum spontaneous spp. aegyptiacum and Miscanthus x giganteus for the production of second-generation bioethanol in semi-arid Mediterranean environment was studied. Crops were established in spring 2002, supplying irrigation and nitrogen fertilization up to 2004/2005 growing season. Subsequently, crops were grown without any agronomic input and harvested annually. Data reported in this paper refers to 2008/2009 and 2009/2010 growing seasons. Aboveground dry matter (DM yield was higher in Arundo (35.4±2.1 Mg ha–1 in 2009 and 32.2±1.9 Mg ha–1 in 2010 harvest than in Saccharum (27.3±2.0 and 23.9±1.9 Mg ha–1, respectively and Miscanthus (19.6±2.8 and 17.2±1.6 Mg ha–1, respectively. Structural polysaccharides of the raw material were higher in Miscanthus (63.4% w/w followed by Saccharum (61.5% w/w and Arundo (57.6% w/w. The same trend was identified for the cellulose content (41.0%, 36.8% and 34.6%, respectively. The highest values in the total hemicellulose complex were observed in Saccharum (24.7%, followed by Arundo (23.1% and Miscanthus (22.4%. The composition of structural polysaccharides leads to a higher theoretical ethanol yield (TEY from one dry ton of Miscanthus feedstock (kg DM Mg–1, followed by Saccharum and Arundo. On the other hand, the TEY per unit surface (Mg ha–1 was greater in Arundo than in Saccharum and Miscanthus. When compared to other lignocellulosic sources used in the second-generation bioethanol technology, such as agricultural residues, woody species and other herbaceous perennial crops, Arundo, Saccharum and Miscanthus showed a great potential in terms of TEY ha–1. Given the high levels of biomass yield and composition of structural polysaccharides, the three species might be introduced into the Mediterranean cropping systems to supply lignocellulosic biomass for second-generation industrial plants

  11. Perennial border reconstruction in the castle park in Lednice

    Directory of Open Access Journals (Sweden)

    Tatiana Kuťková

    2011-01-01

    Full Text Available The objective of the project was to make the design documentation for the reconstruction of the perennial border in the castle park in Lednice. The castle park is a part of Lednice-Valtice Cultural Landscape, which was inscribed in the World Heritage List of UNESCO for its unique value in 1996. The landscape architect of the original project was Markéta Roder-Müller (1898–1981. The result of this project is documenting the flower bed development in time and analysis of design basics, principles and approaches of Müller’s work. The design documentation for perennial border renewal was made with Müller’s landscape design style in mind and time schedule and technologies for perennial border renewal were recommended. Flower bed was reconstructed in autumn of 2010 according to the established design documentation and work schedule.

  12. Precision overhead irrigation is suitable for several Central Valley crops

    Directory of Open Access Journals (Sweden)

    Jeffrey P. Mitchell

    2016-04-01

    Full Text Available Overhead systems are the dominant irrigation technology in many parts of the world, but they are not widely used in California even though they have higher water application efficiency than furrow irrigation systems and lower labor requirements than drip systems. With water and labor perennial concerns in California, the suitability of overhead systems merits consideration. From 2008 through 2013, in studies near Five Points, California, we evaluated overhead irrigation for wheat, corn, cotton, tomato, onion and broccoli as an alternative to furrow and drip irrigation. With the exception of tomato, equal or increased yields were achieved with overhead irrigation. Many variables are involved in the choice of an irrigation system, but our results suggest that, with more research to support best management practices, overhead irrigation may be useful to a wider set of California farmers than currently use it.

  13. 7 CFR 987.6 - Crop year.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Crop year. 987.6 Section 987.6 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE DOMESTIC DATES PRODUCED OR PACKED IN RIVERSIDE COUNTY, CALIFORNIA Order Regulating...

  14. 7 CFR 989.21 - Crop year.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Crop year. 989.21 Section 989.21 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE RAISINS PRODUCED FROM GRAPES GROWN IN CALIFORNIA Order Regulating Handling...

  15. 7 CFR 993.20 - Crop year.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Crop year. 993.20 Section 993.20 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE DRIED PRUNES PRODUCED IN CALIFORNIA Order Regulating Handling Definitions § 993.20...

  16. Effects of cropping system and rates of nitrogen in animal slurry and mineral fertilizer on nitrate leaching from a sandy loam

    DEFF Research Database (Denmark)

    Thomsen, Ingrid Kaag; Hansen, Jørgen Frederik; Kjellerup, Viggo K.

    1993-01-01

    Leaching of nitrate from a sandy loam cropped with spring barley, winter wheat and grass was compared in a 4-year lysimeter study. Crops were grown continuously or in a sequence including sugarbeet. Lysimeters were unfertilized or supplied with equivalent amounts of inorganic nitrogen in calcium...... ley of perennial ryegrass wheat grown in rotation wheat

  17. Effects of the application rate and time of the growth regulator trinexapac-ethyl in seed crops of Lolium perenne L. in relation to spring nitrogen rate

    NARCIS (Netherlands)

    Borm, G.E.L.; Berg, van den W.

    2008-01-01

    To test the effects of the growth regulator trinexapac-ethyl (Moddus 250 EC) in the main seed crop of grasses in the Netherlands, 10 field trials were conducted in perennial ryegrass (Lolium perenne L.). These field trials were carried out in first and second seed harvest crops during 1999¿2002.

  18. Effects of catch crop type and root depth on nitrogen leaching and yield of spring barley

    DEFF Research Database (Denmark)

    Sapkota, Tek Bahadur; Askegaard, Margrethe; Lægdsmand, Mette

    2012-01-01

    [chicory (Cichorium intybus L.), fodder radish (Raphanus sativus L.) and perennial ryegrass (Lolium perenne L.)] and their effect on soil mineral N (NO3− and NH4+) in different soil layers by using the FASSET model. The simulated results of catch crop biomass and root growth and mineral N in the soil...

  19. Photosynthesis in tropical cover crop legumes influenced by irradiance, external carbon dioxide concentration and temperature

    Science.gov (United States)

    In plantation crops perennial tropical legumes are grown as understory plants, receive limited irradiance, and are subjected to elevated levels of CO2 and temperature. Independent short-term effects of photosynthetic photon flux density (PPFD), external carbon dioxide concentration [CO2] and temper...

  20. A mowing strategy to convert red clover to annual crops in organic farming

    Science.gov (United States)

    Organic producers are interested in no-till cropping systems. In this study, we found that perennial clover can be converted to corn without tillage. Conversion tactics involved fall mowing in the third year of red clover, followed by between-row mowing of weeds and volunteer red clover in corn gr...

  1. Symbiotic N2-fixation by the cover crop Pueraria phaseoloides as influenced by litter mineralization

    DEFF Research Database (Denmark)

    Vesterager, J.M.; Østerby, S.; Jensen, E.S.

    1995-01-01

    The perennial legume Pueraria phaseoloides is widely used as a cover crop in rubber and oil palm plantations. However, very little knowledge exists on the effect of litter mineralization from P. phaseoloides on its symbiotic N-2- fixation. The contribution from symbiotic N-2-fixation (Ndfa...

  2. Plan for the uniform mapping of earth resources and environmental complexes from Skylab imagery. Assessment of natural vegetation, environmental, and crop analogs. [Sierra-Lahontan, Colorado Plateau, Louisiana coastal plain, and Northern Great Valley, California

    Science.gov (United States)

    Poulton, C. E. (Principal Investigator); Welch, R. I.

    1975-01-01

    The author has identified the following significant results. For interpreting a wide range of natural vegetation analogs, S-190A color infrared and the ERTS-1 color composite were consistently more useful than were conventional color or black and white photos. Color infrared was superior for five vegetation analogs while color was superior for only three. The errors in identification appeared to associate more with black and white single band images than with multiband color. For rice crop analogs, spectral and spatial discriminations both contribute to the usefulness of images for data collection. Tests and subjective analyses conducted in this study indicated that the spectral bands exploited in color infrared film were the most useful for agricultural crop analysis. Accuracy of crop identification on any single date of Skylab images was less than that of multidate analysis due to differences in crop calendar, cultural practices used, rice variety, planting date, planting method, water use, fertilization, disease, or mechanical problems.

  3. Establishing perennial seed-based energy crops on reclaimed surface mine soils in the central Appalachians

    Science.gov (United States)

    Jamie L. Schuler; Shawn Grushecky; Jingxin. Wang

    2014-01-01

    Renewable energy has been at the forefront of the United States' energy policies. Cellulosic feedstocks have received considerable interest in the Appalachian region because of their abundance and availability, but cost competition from other energy sectors has limited their use in the region. Some other bioenergy feedstocks, such as corn and soybeans, are not a...

  4. Genomic Selection in Commercial Perennial Crops: Applicability and Improvement in Oil Palm (Elaeis guineensis Jacq.).

    Science.gov (United States)

    Kwong, Qi Bin; Ong, Ai Ling; Teh, Chee Keng; Chew, Fook Tim; Tammi, Martti; Mayes, Sean; Kulaveerasingam, Harikrishna; Yeoh, Suat Hui; Harikrishna, Jennifer Ann; Appleton, David Ross

    2017-06-06

    Genomic selection (GS) uses genome-wide markers to select individuals with the desired overall combination of breeding traits. A total of 1,218 individuals from a commercial population of Ulu Remis x AVROS (UR x AVROS) were genotyped using the OP200K array. The traits of interest included: shell-to-fruit ratio (S/F, %), mesocarp-to-fruit ratio (M/F, %), kernel-to-fruit ratio (K/F, %), fruit per bunch (F/B, %), oil per bunch (O/B, %) and oil per palm (O/P, kg/palm/year). Genomic heritabilities of these traits were estimated to be in the range of 0.40 to 0.80. GS methods assessed were RR-BLUP, Bayes A (BA), Cπ (BC), Lasso (BL) and Ridge Regression (BRR). All methods resulted in almost equal prediction accuracy. The accuracy achieved ranged from 0.40 to 0.70, correlating with the heritability of traits. By selecting the most important markers, RR-BLUP B has the potential to outperform other methods. The marker density for certain traits can be further reduced based on the linkage disequilibrium (LD). Together with in silico breeding, GS is now being used in oil palm breeding programs to hasten parental palm selection.

  5. INFLUENCE OF MICROWAVE IRRADIATION ON SOME VITALITY INDICES AND ELECTROCONDUCTIVITY OF ORNAMENTAL PERENNIAL CROPS

    Directory of Open Access Journals (Sweden)

    A ALADJADJIYAN

    2003-04-01

    Full Text Available The effect of microwave irradiation with a wavelength of 12 cm on the germinating energy and germination of seeds of Gleditschia triacanthos L., Caragana arborescens, Laburnum anagiroides Med., Robinia pseudoacacia L. has been studied. The specific electroconductivity of leaf extracts has been measured and its dependence on the microwave radiation power has been determined.

  6. The Perennial and the Particular Challenges of Design Education

    Science.gov (United States)

    Ruecker, Stan

    2012-01-01

    Education in design shares with other disciplines a number of perennial challenges, including the need to transfer human culture, the choice of what parts of human culture to transfer and the decision as to what approaches work best in accomplishing that transfer. Design education also faces particular challenges, which are shared with only a few…

  7. Establishing the basis for Genomic Prediction in Perennial Ryegrass

    DEFF Research Database (Denmark)

    Fé, Dario

    2015-01-01

    ryegrass (Lolium perenne L.), which is the most cultivated forage grass in temperate regions. Different statistical models were used for predicting the phenotypes of perennial ryegrass families, across diffent environments. Results showed good prospects for GS implementation in forage breeding, due...

  8. Hydrologic properties of grazed perennial swards in semiarid ...

    African Journals Online (AJOL)

    hope&shola

    2009-02-07

    Feb 7, 2009 ... The results support the existence of a threshold level of sward stubble height for minimizing runoff. Key words: Perennial swards, water infiltration capacity, runoff thresholds. INTRODUCTION. The trade-offs .... include different drought tolerant varieties of maize, sorghum, millet, pigeon peas and beans.

  9. Senescence, dormancy and tillering in perennial C4 grasses

    Science.gov (United States)

    Perennial, temperate, C4 warm-season grasses, such as switchgrass and miscanthus have been tabbed as sources of herbaceous biomass for the production of green fuels and chemicals based on a number of positive agronomic traits. Although there is important literature on the management of these specie...

  10. Survival of perennial carbon dioxide ice caps on Mars

    Science.gov (United States)

    Byrne, S.; Hayne, P. O.; Becerra, P.

    2017-09-01

    Perennial CO2 ice caps on Mars roughen unstably generating expanding pits that are observed by spacecraft. We tie observations of the surface and atmosphere together with landscape evolution models to explain this phenomenon and predict a polar cap that waxes and wanes over timescales of 100 yrs.

  11. Combining mechanical rhizome removal and cover crops for Elytrigia repens control in organic barley systems

    DEFF Research Database (Denmark)

    Melander, B; Nørremark, M; Kristensen, E F

    2013-01-01

    Mechanical weed control of perennial weeds in organic crop production over long post-harvest periods is incompatible with the establishment of cover crops for improving soil quality and preventing nutrient leaching. We suggest a new concept that comprises uprooting and immediate removal of vegeta......Mechanical weed control of perennial weeds in organic crop production over long post-harvest periods is incompatible with the establishment of cover crops for improving soil quality and preventing nutrient leaching. We suggest a new concept that comprises uprooting and immediate removal......, the cover crop developed poorly and did not affect barley or E. repens. Barley yield was only affected by treatments in the first season, where yield was negatively correlated with E. repens shoot biomass. The concept has potential for the control of severe E. repens infestations, but future research aimed...

  12. Haploid and Doubled Haploid Techniques in Perennial Ryegrass (Lolium perenne L. to Advance Research and Breeding

    Directory of Open Access Journals (Sweden)

    Rachel F. Begheyn

    2016-11-01

    Full Text Available The importance of haploid and doubled haploid (DH techniques for basic and applied research, as well as to improve the speed of genetic gain when applied in breeding programs, cannot be overstated. They have become routine tools in several major crop species, such as maize (Zea mays L., wheat (Triticum aestivum L., and barley (Hordeum vulgare L.. DH techniques in perennial ryegrass (Lolium perenne L., an important forage species, have advanced to a sufficiently successful and promising stage to merit an exploration of what their further developments may bring. The exploitation of both in vitro and in vivo haploid and DH methods to (1 purge deleterious alleles from germplasm intended for breeding; (2 develop mapping populations for genetic and genomic studies; (3 simplify haplotype mapping; (4 fix transgenes and mutations for functional gene validation and molecular breeding; and (5 hybrid cultivar development are discussed. Even with the comparatively modest budgets of those active in forage crop improvement, haploid and DH techniques can be developed into powerful tools to achieve the acceleration of the speed of genetic gain needed to meet future agricultural demands.

  13. Estimated Perennial Streams of Idaho and Related Geospatial Datasets

    Science.gov (United States)

    Rea, Alan; Skinner, Kenneth D.

    2009-01-01

    The perennial or intermittent status of a stream has bearing on many regulatory requirements. Because of changing technologies over time, cartographic representation of perennial/intermittent status of streams on U.S. Geological Survey (USGS) topographic maps is not always accurate and (or) consistent from one map sheet to another. Idaho Administrative Code defines an intermittent stream as one having a 7-day, 2-year low flow (7Q2) less than 0.1 cubic feet per second. To establish consistency with the Idaho Administrative Code, the USGS developed regional regression equations for Idaho streams for several low-flow statistics, including 7Q2. Using these regression equations, the 7Q2 streamflow may be estimated for naturally flowing streams anywhere in Idaho to help determine perennial/intermittent status of streams. Using these equations in conjunction with a Geographic Information System (GIS) technique known as weighted flow accumulation allows for an automated and continuous estimation of 7Q2 streamflow at all points along a stream, which in turn can be used to determine if a stream is intermittent or perennial according to the Idaho Administrative Code operational definition. The selected regression equations were applied to create continuous grids of 7Q2 estimates for the eight low-flow regression regions of Idaho. By applying the 0.1 ft3/s criterion, the perennial streams have been estimated in each low-flow region. Uncertainty in the estimates is shown by identifying a 'transitional' zone, corresponding to flow estimates of 0.1 ft3/s plus and minus one standard error. Considerable additional uncertainty exists in the model of perennial streams presented in this report. The regression models provide overall estimates based on general trends within each regression region. These models do not include local factors such as a large spring or a losing reach that may greatly affect flows at any given point. Site-specific flow data, assuming a sufficient period of

  14. 30 CFR 816.57 - Hydrologic balance: Activities in or adjacent to perennial or intermittent streams.

    Science.gov (United States)

    2010-07-01

    ... to perennial or intermittent streams. 816.57 Section 816.57 Mineral Resources OFFICE OF SURFACE... or adjacent to perennial or intermittent streams. (a)(1) Buffer requirement. Except as provided in..., measured horizontally, of a perennial or intermittent stream, unless the regulatory authority authorizes...

  15. Sustainable commercialization of new crops for the agricultural bioeconomy

    Directory of Open Access Journals (Sweden)

    N.R. Jordan

    2016-01-01

    Full Text Available Abstract Diversification of agroecological systems to enhance agrobiodiversity is likely to be critical to advancing environmental, economic, and social sustainability of agriculture. Temperate-zone agroecological systems that are currently organized for production of summer-annual crops can be diversified by integration of fallow-season and perennial crops. Integration of such crops can improve sustainability of these agroecological systems, with minimal interference with current agricultural production. Importantly, these crops can provide feedstocks for a wide range of new bio-products that are forming a new agricultural bioeconomy, potentially providing greatly increased economic incentives for diversification. However, while there are many fallow-season and perennial crops that might be used in such a “bioeconomic” strategy for diversification, most are not yet well adapted and highly-marketable. Efforts are underway to enhance adaptation and marketability of many such crops. Critically, these efforts require a strategic approach that addresses the inherent complexity of these projects. We outline a suitable approach, which we term “sustainable commercialization”: a coordinated innovation process that integrates a new crop into the agriculture of a region, while intentionally addressing economic, environmental and social sustainability challenges via multi-stakeholder governance. This approach centers on a concerted effort to coordinate and govern innovation in three critical areas: germplasm development, multifunctional agroecosystem design and management, and development of end uses, supply chains, and markets. To exemplify the approach, we describe an ongoing effort to commercialize a new fallow-season crop, field pennycress (Thlaspi arvense L..

  16. Influence of crop rotation, intermediate crops, and organic fertilizers on the soil enzymatic activity and humus content in organic farming systems

    Science.gov (United States)

    Marcinkeviciene, A.; Boguzas, V.; Balnyte, S.; Pupaliene, R.; Velicka, R.

    2013-02-01

    The influence of crop rotation systems with different portions of nitrogen-fixing crops, intermediate crops, and organic fertilizers on the enzymatic activity and humus content of soils in organic farming was studied. The highest activity of the urease and invertase enzymes was determined in the soil under the crop rotation with 43% nitrogen-fixing crops and with perennial grasses applied twice per rotation. The application of manure and the growing of intermediate crops for green fertilizers did not provide any significant increase in the content of humus. The activity of urease slightly correlated with the humus content ( r = 0.30 at the significance level of 0.05 and r = 0.39 at the significance level of 0.01).

  17. Crop-insurance

    NARCIS (Netherlands)

    Wijk, van der S.

    1945-01-01

    Crop insurance was fairly new in the Netherlands but there was no legal objection or limitation to particular crops. If a crop were insured, it was important that the whole area of the crop were insured. Speculative insurance seemed preferable to mutual insurance.

    Crop insurance covered all risks

  18. California Air Basins

    Data.gov (United States)

    California Department of Resources — Air ResourcesCalifornia Air Resources BoardThe following datasets are from the California Air Resources Board: * arb_california_airbasins - California Air BasinsThe...

  19. Nutrient uptake and biomass accumulation for eleven different field crops

    Directory of Open Access Journals (Sweden)

    K. HAKALA

    2008-12-01

    Full Text Available Oil hemp (Cannabis sativa L., quinoa (Chenopodium quinoa Willd., false flax (Camelina sativa (L. Crantz, caraway (Carum carvi L., dyer’s woad (Isatis tinctoria L., nettle (Urtica dioica L., reed canary grass (RCG (Phalaris arundinacea L., buckwheat (Fagopyrum esculentum Moench, linseed (Linum usitatissimum L., timothy (Phleum pratense L. and barley (Hordeum vulgare L. were grown under uniform conditions in pots containing well fertilised loam soil. Dry matter (DM accumulation was measured repeatedly, and contents of minerals N, P, K, Ca and Mg at maturity. Annual crops accumulated above-ground biomass faster than perennials, while perennials had higher DM accumulation rates below ground. Seeds had high concentrations of N and P, while green biomass had high concentrations of K and Ca. Stems and roots had low concentrations of minerals. Concentrations of K and P were high in quinoa and caraway, and that of P in buckwheat. Hemp and nettle had high Ca concentrations, and quinoa had high Mg concentration. N and P were efficiently harvested with seed, Ca and K with the whole biomass. Perennials could prevent soil erosion and add carbon to the soil in the long term, while annuals compete better with weeds and prevent erosion during early growth. Nutrient balances in a field could be modified and nutrient leaching reduced by careful selection of the crop and management practices.;

  20. Evaluation of herbacceous biomass crops in the northern Great Plains. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, D.W.; Norby, W.E.; Erickson, D.O.; Johnson, R.G. [North Dakota State Univ., Fargo, ND (United States)

    1994-08-01

    Herbaceous lignocellulose crops are a potential renewable feedstock for biochemical conversion systems second in size to wood products. Several herbaceous crops are utilized as forage crops in the northern Great Plains, but forage quality considerations usually dictates a early harvest. Biomass cropping does not have this constraint; therefore, little information was available on herbaceous crops utilized as energy crops prior to this project. Our primary objectives were to evaluate the biomass yield and select chemical components of several herbaceous crops for energy crops in the northern Great Plains, compare the economic feasibility of energy crops with common competing crops, and evaluate biomass cropping on summer fallow lands. Three good, two marginal, and one irrigated sites were used during 1988 to 1992 for the first component. At least six perennial and four annual biomass species were included at all sites. Three to four nitrogen (N) levels and a crop-recrop comparison (annuals only) were management intensities included. Biomass cropping on idled lands was performed on dryland at Carrington and evaluated the effects of removing leguminous biomass on fallowed lands. This report summarizes results from the 5-year project.

  1. Development and annotation of perennial Triticeae ESTs and SSR markers.

    Science.gov (United States)

    Bushman, B Shaun; Larson, Steve R; Mott, Ivan W; Cliften, Paul F; Wang, Richard R-C; Chatterton, N Jerry; Hernandez, Alvaro G; Ali, Shahjahan; Kim, Ryan W; Thimmapuram, Jyothi; Gong, George; Liu, Lei; Mikel, Mark A

    2008-10-01

    Triticeae contains hundreds of species of both annual and perennial types. Although substantial genomic tools are available for annual Triticeae cereals such as wheat and barley, the perennial Triticeae lack sufficient genomic resources for genetic mapping or diversity research. To increase the amount of sequence information available in the perennial Triticeae, three expressed sequence tag (EST) libraries were developed and annotated for Pseudoroegneria spicata, a mixture of both Elymus wawawaiensis and E. lanceolatus, and a Leymus cinereus x L. triticoides interspecific hybrid. The ESTs were combined into unigene sets of 8 780 unigenes for P. spicata, 11 281 unigenes for Leymus, and 7 212 unigenes for Elymus. Unigenes were annotated based on putative orthology to genes from rice, wheat, barley, other Poaceae, Arabidopsis, and the non-redundant database of the NCBI. Simple sequence repeat (SSR) markers were developed, tested for amplification and polymorphism, and aligned to the rice genome. Leymus EST markers homologous to rice chromosome 2 genes were syntenous on Leymus homeologous groups 6a and 6b (previously 1b), demonstrating promise for in silico comparative mapping. All ESTs and SSR markers are available on an EST information management and annotation database (http://titan.biotec.uiuc.edu/triticeae/).

  2. Hybridization of cultivated Vitis vinifera with wild V. californica and V. girdiana in California.

    Science.gov (United States)

    Dangl, Gerald S; Mendum, Mary Lou; Yang, Judy; Walker, M Andrew; Preece, John E

    2015-12-01

    Hybridization of introduced domesticates and closely related natives is well documented in annual crops. The widespread introduction of the domesticated grapevine, Vitis vinifera, into California where it overlaps with two native congenerics, with which it is interfertile, provides opportunity to investigate hybridization between woody perennials. Although geographically widespread, the introduction over the past two centuries has been limited to a few elite clonal cultivars, providing a unique opportunity to study the effects of hybridization on the native species. The amount of hybridization with V. vinifera and the genetic diversity of wild-growing Vitis californica and Vitis girdiana were examined using nineteen microsatellite markers. STRUCTURE analysis was used to define hybrid and introgressed individuals and to analyze genetic structure of the native species. FAMOZ software was used to identify which V. vinifera cultivars served as parents of F 1 hybrids. The three species were clearly distinguished by STRUCTURE analysis. Thirty percent of 119 V. californica vines were hybrids. The domesticated parent was identified for 16 F 1 hybrid vines; the original California cultivar, 'Mission', was the parent of eight. Backcrosses were also found, showing introgression into subsequent generations. Similar results were obtained for a small sample of V. girdiana. Removing hybrids greatly reduced the genetic variation of the presumed pure species, among which there was essentially no genetic structure. Limited genetic variability indicates the California natives may be threatened by genetic erosion. The discovery of F 1 hybrids of 'Mission', a cultivar not grown in the areas for ~100 years, suggests long generation times for wild vines that, often, grow into expansive liana and propagate by layering, all factors that limit recruitment in populations already disjunct by habitat lose. Hermaphroditic flowers and fruit that is more attractive to birds may favor the

  3. Productivity and nutrient cycling in bioenergy cropping systems

    Science.gov (United States)

    Heggenstaller, Andrew Howard

    One of the greatest obstacles confronting large-scale biomass production for energy applications is the development of cropping systems that balance the need for increased productive capacity with the maintenance of other critical ecosystem functions including nutrient cycling and retention. To address questions of productivity and nutrient dynamics in bioenergy cropping systems, we conducted two sets of field experiments during 2005-2007, investigating annual and perennial cropping systems designed to generate biomass energy feedstocks. In the first experiment we evaluated productivity and crop and soil nutrient dynamics in three prototypical bioenergy double-crop systems, and in a conventionally managed sole-crop corn system. Double-cropping systems included fall-seeded forage triticale (x Triticosecale Wittmack), succeeded by one of three summer-adapted crops: corn (Zea mays L.), sorghum-sudangrass [Sorghum bicolor (L.) Moench], or sunn hemp (Crotalaria juncea L.). Total dry matter production was greater for triticale/corn and triticale/sorghum-sudangrass compared to sole-crop corn. Functional growth analysis revealed that photosynthetic duration was more important than photosynthetic efficiency in determining biomass productivity of sole-crop corn and double-crop triticale/corn, and that greater yield in the tiritcale/corn system was the outcome of photosynthesis occurring over an extended duration. Increased growth duration in double-crop systems was also associated with reductions in potentially leachable soil nitrogen relative to sole-crop corn. However, nutrient removal in harvested biomass was also greater in the double-crop systems, indicating that over the long-term, double-cropping would mandate increased fertilizer inputs. In a second experiment we assessed the effects of N fertilization on biomass and nutrient partitioning between aboveground and belowground crop components, and on carbon storage by four perennial, warm-season grasses: big bluestem

  4. A transcriptome map of perennial ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Studer Bruno

    2012-04-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs are increasingly becoming the DNA marker system of choice due to their prevalence in the genome and their ability to be used in highly multiplexed genotyping assays. Although needed in high numbers for genome-wide marker profiles and genomics-assisted breeding, a surprisingly low number of validated SNPs are currently available for perennial ryegrass. Results A perennial ryegrass unigene set representing 9,399 genes was used as a reference for the assembly of 802,156 high quality reads generated by 454 transcriptome sequencing and for in silico SNP discovery. Out of more than 15,433 SNPs in 1,778 unigenes fulfilling highly stringent assembly and detection parameters, a total of 768 SNP markers were selected for GoldenGate genotyping in 184 individuals of the perennial ryegrass mapping population VrnA, a population being previously evaluated for important agronomic traits. A total of 592 (77% of the SNPs tested were successfully called with a cluster separation above 0.9. Of these, 509 (86% genic SNP markers segregated in the VrnA mapping population, out of which 495 were assigned to map positions. The genetic linkage map presented here comprises a total of 838 DNA markers (767 gene-derived markers and spans 750 centi Mogan (cM with an average marker interval distance of less than 0.9 cM. Moreover, it locates 732 expressed genes involved in a broad range of molecular functions of different biological processes in the perennial ryegrass genome. Conclusions Here, we present an efficient approach of using next generation sequencing (NGS data for SNP discovery, and the successful design of a 768-plex Illumina GoldenGate genotyping assay in a complex genome. The ryegrass SNPs along with the corresponding transcribed sequences represent a milestone in the establishment of genetic and genomics resources available for this species and constitute a further step towards molecular breeding

  5. Suppression of Bromus tectorum L. by Established Perennial Grasses: Potential Mechanisms—Part One

    Directory of Open Access Journals (Sweden)

    Robert R. Blank

    2012-01-01

    Full Text Available Bromus tectorum L. (cheatgrass is an Eurasian annual grass that has invaded ecosystems throughout the Intermountain west of the United States. Our purpose was to examine mechanisms by which established perennial grasses suppress the growth of B. tectorum. Using rhizotrons, the experiment was conducted over 5 growth cycles: (1 B. tectorum planted between perennial grasses; (2 perennials clipped and B. tectorum planted; (3 perennials clipped and B. tectorum planted into soil mixed with activated carbon; (4 perennials clipped, B. tectorum planted, and top-dressed with fertilizer, and; (5 perennial grasses killed and B. tectorum planted. Water was not limiting in this study. Response variables measured at the end of each growth cycle included above-ground mass and tissue nutrient concentrations. Relative to controls (B. tectorum without competition, established perennial grasses significantly hindered the growth of B. tectorum. Overall, biomass of B. tectorum, grown between established perennials, increased considerably after fertilizer addition and dramatically upon death of the perennials. Potential mechanisms involved in the suppression of B. tectorum include reduced nitrogen (possibly phosphorus availability and coopting of biological soil space by perennial roots. Our data cannot confirm or reject allelopathic suppression. Understanding the mechanisms involved with suppression may lead to novel control strategies against B. tectorum.

  6. Ecoinformatics reveals effects of crop rotational histories on cotton yield.

    Directory of Open Access Journals (Sweden)

    Matthew H Meisner

    Full Text Available Crop rotation has been practiced for centuries in an effort to improve agricultural yield. However, the directions, magnitudes, and mechanisms of the yield effects of various crop rotations remain poorly understood in many systems. In order to better understand how crop rotation influences cotton yield, we used hierarchical Bayesian models to analyze a large ecoinformatics database consisting of records of commercial cotton crops grown in California's San Joaquin Valley. We identified several crops that, when grown in a field the year before a cotton crop, were associated with increased or decreased cotton yield. Furthermore, there was a negative association between the effect of the prior year's crop on June densities of the pest Lygus hesperus and the effect of the prior year's crop on cotton yield. This suggested that some crops may enhance L. hesperus densities in the surrounding agricultural landscape, because residual L. hesperus populations from the previous year cannot continuously inhabit a focal field and attack a subsequent cotton crop. In addition, we found that cotton yield declined approximately 2.4% for each additional year in which cotton was grown consecutively in a field prior to the focal cotton crop. Because L. hesperus is quite mobile, the effects of crop rotation on L. hesperus would likely not be revealed by small plot experimentation. These results provide an example of how ecoinformatics datasets, which capture the true spatial scale of commercial agriculture, can be used to enhance agricultural productivity.

  7. Earthworm populations and functional traits in a land-use gradient of annual, perennial and permanent grassland systems in a heterogenic agricultural landscape

    Science.gov (United States)

    Emmerling, Christoph; Ruf, Thorsten

    2017-04-01

    Soil use is the key driving factor for the composition of the detritus food webs, for SOM quantity and quality, and related soil properties. Many studies have identified land-use change as a major driver affecting soil biodiversity, which severely influences soil functioning and the ecosystem services they deliver. The overall intention of the study was to gain insights in future trends of soil ecology in a changing land-use towards bioenergy production. Therefor we investigated earthworm responses to different land-use intensities, such as rotational cropping with maize (1G), cultivation of perennial crops (2G), like Szarvasi, Silphie, Igniscum and Miscanthus, and permanent grasslands at landscape scale in Western Germany. We analyzed species composition, individual numbers and biomass, and earthworm functional traits. We can conclude that on average the investigated earthworm parameters of the newly introduced second generation bioenergy crops took a medium position between annual maize and permanent grassland sites. In addition, the experiments clearly emphasized that some results were in a clear trend, but others were site-depended and to some extend indifferent. We will critically discuss the ecological significance of perennial land-use systems from a soil biodiversity and soil functioning point of view.

  8. Landscape patterns of bioenergy in a changing climate: implications for crop allocation and land-use competition

    Science.gov (United States)

    Rose A. Graves; Scott M. Pearson; Monica G. Turner

    2016-01-01

    Rural landscapes face changing climate, shifting development pressure, and loss of agricultural land. Perennial bioenergy crops grown on existing agricultural land may provide an opportunity to conserve rural landscapes while addressing increased demand for biofuels. However, increased bioenergy production and changing land use raise concerns for tradeoffs...

  9. Field-based estimates of global warming potential in bioenergy systems of Hawaii: Crop choice and deficit irrigation

    Science.gov (United States)

    Replacing fossil fuel with biofuel is environmentally viable only if the net greenhouse gas (GHG) footprint of the system is reduced. The effects of replacing annual arable crops with perennial bioenergy feedstocks on net GHG production and soil carbon (C) stock are critical to the system-level bal...

  10. An undergraduate student project to improve mechanical control of perenial nutsedges with a peanut digger in organic crop production

    Science.gov (United States)

    Perennial nutsedges are difficult to control in organic crop production systems. Tubers are generally confined to the upper portions of the soil profile and vulnerable to desiccation when on the soil surface. A peanut digger is a common implement found in the coastal plain region of the southeaste...

  11. California Rare Endemics and Climate Change

    Science.gov (United States)

    Espinoza, M.

    2010-12-01

    California is known for its wide variety of endemic flora, from its annuals such as the Eschscholzia californica (California poppy) to the perennials like the Arctostaphylos pallida (Alameda manzanita), which happens to be a rare species. Each species plays an important role in the biodiversity of California, yet there are species that are threatened, not only by human interaction and urbanization, but by climate change. Species that we seldom see are now on the verge of becoming eradicated; rare endemics similar to Arctostaphylos pallida are now facing a new challenge that may severely impair their survival. The climate has changed significantly over the twentieth century and it has affected the distribution of rare endemics in California, both geographically as well as within their climatic and edaphic niches. Lilaeopsis masonii is just one rare endemic, however it serves as a representative of the other 23 species that were studied. Using Maxent, a climate-modeling program, it was viable to construct two climate envelopes of the masonii species: the early century envelope (1930-1959) and the later century envelope (1990-2009). When these two climate envelopes were compared, it became clear that the later century climate envelope had contracted radically, reshaping the climate niche of all rare endemics in California due to an increase in temperature. It is possible to conclude that the future of rare endemics hangs in the balance, where one degree higher in temperature is enough to topple the scale.

  12. The impact of roots on soil organic carbon dynamics in annual and perennial agricultural systems

    Science.gov (United States)

    Beniston, J.; Dupont, T.; Glover, J.; Lal, R.

    2012-12-01

    Identifying and developing agricultural systems capable of transferring large quantities of carbon (C) to the soil and sustaining ecosystem processes and services is a priority for ecological researchers and land managers. Temperate grasslands have extensive root systems and transfer large quantities of C to the soil organic C (SOC) pool, which has lead to widespread interest in utilizing perennial grasses as both bioenergy crops and as a model for perennial grains. This study examined five sites in north central Kansas (U.S.A.) that contain the unique land use pairing of tall grass prairie meadows (PM) that have been harvested annually for hay for the past 75 years and annual grain (wheat) production fields (AG) that have been cultivated for a similar length of time, all on deep alluvial soils. Specific research objectives included: 1) To quantify below-ground biomass pools and root C contributions in the two systems; 2) To analyze and compare SOC pools and SOC concentration in primary particle size fractions in the two systems; 3) To utilize natural abundance δ13C signatures to determine the source and turnover of SOC in the soils of the AG sites; and 4) To elucidate the relationship of roots to both SOC pools and nematode food webs. Soil core samples were collected to a depth of 1 m in May and June 2008. Soil samples were analyzed for SOC, microbial biomass C (MBC), nematodes, and a particle size fractionation of SOC in coarse (>250 μm), particulate organic matter (POM) (53-250 μm), silt (2-53 μm), and clay (<2 μm) sized fractions. Root biomass, root length and root C were also analyzed to a depth of 1 m. Natural abundance δ13C values were obtained for all C parameters. Soils under PM had 4 times as much root C as AG soils to 1 m depth in mid May (PM 2.8 Mg ha-1 and AG 0.7 Mg ha-1) and 7 times as much root C to 1 m depth in late June (PM 3.5 Mg ha-1 and AG 0.5 Mg ha-1). The MBC pools were significantly larger in grassland soils to a depth of 60 cm in May

  13. African Crop Science Journal

    African Journals Online (AJOL)

    The African Crop Science Journal, a quarterly publication, publishes original research papers dealing with all aspects of crop agronomy, production, genetics and breeding, germplasm, crop protection, post harvest systems and utilisation, agro-forestry, crop-animal interactions, information science, environmental science ...

  14. Effects of native grass cover crops on beneficial and pest invertebrates in Australian vineyards.

    Science.gov (United States)

    Danne, A; Thomson, L J; Sharley, D J; Penfold, C M; Hoffmann, A A

    2010-06-01

    Indigenous cover crops have the potential to promote an increase in natural enemies providing fortuitous control of pest species and other ecosystem services. We test this idea in a vineyard in south eastern Australia, where reduced water availability because of drought coupled with increased temperatures has generated interest in sustainable alternatives to the exotic perennial cover crops commonly planted. Three endemic perennial cover crops, comprising the grasses Austrodanthonia richardsonii and Chloris truncata and a mix of two saltbushes (Atriplex semibaccata and Atriplex suberecta) were established as cover crops and compared with introduced oats (Avena sativa). Abundance of a range of predators and parasitoids was higher in vines with native cover crops compared with the oat control. In addition, predation levels of sentinel eggs of a common vineyard pest, light brown apple moth (Epiphyas postvittana), were increased in the native cover crops. However, the native cover crops also increased the abundance of some potential pest species. Native plants therefore have potential to increase abundance of beneficial invertebrates that assist in pest control, but need to be used carefully to ensure that they do not increase local pest problems.

  15. Recent additions to the collection funds of Botanic Garden of Petrozavodsk State University. Perennial ornamental plants

    Directory of Open Access Journals (Sweden)

    Platonova Elena

    2014-11-01

    Full Text Available Most important task for the botanical gardens is the introduction of new species, forms and cultivars of useful plants. This study summarizes the results of the first stages of the introduction of 255 species of perennial herbaceous plants new to Karelia in Botanic Garden of Petrozavodsk State University. The seeds of hardy plants (USDA zones 3-4 were received from 97 botanical gardens in the world. Species belong to 27 families. Geographic area of investigated plants covers different regions of Asia-Temperate, Europe and North America. Several species are rare and endangered of habitat within areas of natural distribution. Some species are rarely used in horticultural crops in Russia and are suggest for gardens and parks. Investigated plants will be placed to the following thematic departments of Botanical Garden: "Shadow Garden" - 41 species, "Sunny Garden" - 80 species (22 species of them may be used for the geographic exposure "American prairie", exposure of Arcto-Alpine flora - 86 species, exposure of spicy plants - 16 species etc. The most of species will be perspective to the landscape gardening in Karelia.

  16. [Biofuels, food security and transgenic crops].

    Science.gov (United States)

    Acosta, Orlando; Chaparro-Giraldo, Alejandro

    2009-01-01

    Soaring global food prices are threatening to push more poor people back below the poverty line; this will probably become aggravated by the serious challenge that increasing population and climate changes are posing for food security. There is growing evidence that human activities involving fossil fuel consumption and land use are contributing to greenhouse gas emissions and consequently changing the climate worldwide. The finite nature of fossil fuel reserves is causing concern about energy security and there is a growing interest in the use of renewable energy sources such as biofuels. There is growing concern regarding the fact that biofuels are currently produced from food crops, thereby leading to an undesirable competition for their use as food and feed. Nevertheless, biofuels can be produced from other feedstocks such as lingo-cellulose from perennial grasses, forestry and vegetable waste. Biofuel energy content should not be exceeded by that of the fossil fuel invested in its production to ensure that it is energetically sustainable; however, biofuels must also be economically competitive and environmentally acceptable. Climate change and biofuels are challenging FAO efforts aimed at eradicating hunger worldwide by the next decade. Given that current crops used in biofuel production have not been domesticated for this purpose, transgenic technology can offer an enormous contribution towards improving biofuel crops' environmental and economic performance. The present paper critically presents some relevant relationships between biofuels, food security and transgenic plant technology.

  17. Fine mapping a self-fertility locus in perennial ryegrass.

    Science.gov (United States)

    Do Canto, Javier; Studer, Bruno; Frei, Ursula; Lübberstedt, Thomas

    2017-12-15

    A self-fertility locus was fine mapped to a 1.6 cM region on linkage group 5 in a perennial ryegrass population. This locus was the main determinant of pollen self-compatibility. In grasses, self-incompatibility (SI) is characterized by a two-loci gametophytic (S and Z) mechanism acting together in the recognition and inhibition of self-pollen. Mutations affecting the expression of SI have been reported in a few grass species. In perennial ryegrass (Lolium perenne L.), a mutation independent from S and Z, and mapping on linkage group 5 (LG 5), was previously reported to produce self-fertile plants. Here, we describe fine mapping of the self-fertility (SF) gene in a perennial ryegrass population and determine whether there is any effect of other genomic regions on the pollen compatibility. The phenotypic segregation of SF showed a bimodal distribution with one mean at 49% pollen compatibility and the other at 91%. Marker-trait association analysis showed that only markers on LG 5 were significantly associated with the trait. A single gene model explained 82% of the observed variability and no effects of the other regions were detected. Using segregation and linkage analysis, the SF locus was located to a 1.6 cM region on LG 5. The flanking marker sequences were aligned to rice and Brachypodium distachyon reference genomes to estimate the physical distance. We provide markers tightly linked to SF that can be used for introgression of this trait into advanced breeding germplasm. Moreover, our results represent a further step towards the identification of the SF gene in LG 5.

  18. Molecular Characterization Of The Vernalization Locus VRN1 In Perennial Ryegrass

    DEFF Research Database (Denmark)

    Asp, Torben; Byrne, Stephen; Andersen, Jeppe R

    in perennial ryegrass (Lolium perenne). Two allelic BAC clones of the VRN1 locus from the two genotypes Veyo and Falster with contrasting vernalization requirements were identified, sequenced, and characterized. The region surrounding the VRN1 locus in perennial ryegrass showed micro...... vernalization requirement. Our findings suggest that the 8.6kb region in the first intron of the VRN1 gene is an important regulatory region for vernalization response in perennial ryegrass....

  19. The role of H2 antagonists in perennial allergic rhinitis.

    Science.gov (United States)

    Testa, B; Mesolella, C; Filippini, P; Campagnano, N; Testa, D; Mesolella, M; Sagnelli, E

    1993-09-01

    The biological effects of anti-H2 in allergic reactions are dose dependent: low doses enhance, and high doses significantly decrease the reaction of hypersensitivity. The administration of cimetidine H2 antagonist to 20 perennial allergic rhinitis patients brought about an abatement in the symptoms and a decrease in the total serum immunoglobulin E (IgE) levels in 72% of treated patients, but no variation was perceived in placebo-treated patients. These results strengthen the hypothesis of anti-H2-induced immunoregulatory effects and suggest a possible way of inhibiting IgE synthesis in vivo.

  20. De novo assembly of the perennial ryegrass transcriptome using an RNA-seq strategy

    DEFF Research Database (Denmark)

    Farrell, Jacqueline Danielle; Byrne, Stephen; Paina, Cristiana

    2014-01-01

    Background Perennial ryegrass is a highly heterozygous outbreeding grass species used for turf and forage production. Heterozygosity can affect de-Bruijn graph assembly making de novo transcriptome assembly of species such as perennial ryegrass challenging. Creating a reference transcriptome from...... a homozygous perennial ryegrass genotype can circumvent the challenge of heterozygosity. The goals of this study were to perform RNA-sequencing on multiple tissues from a highly inbred genotype to develop a reference transcriptome. This was complemented with RNA-sequencing of a highly heterozygous genotype...... has developed an annotated, comprehensive transcriptome reference for perennial ryegrass that can aid in determining genetic variation, expression analysis, genome annotation, and gene mapping....

  1. Biogas production from energy crops and agriculture residues

    Energy Technology Data Exchange (ETDEWEB)

    Wang, G.

    2010-12-15

    In this thesis, the feasibility of utilizing energy crops (willow and miscanthus) and agriculture residues (wheat straw and corn stalker) in an anaerobic digestion process for biogas production was evaluated. Potential energy crops and agriculture residues were screened according to their suitability for biogas production. Moreover, pretreatment of these biomasses by using wet explosion method was studied and the effect of the wet explosion process was evaluated based on the increase of (a) sugar release and (b) methane potential when comparing the pretreated biomass and raw biomass. Ensiling of perennial crops was tested as a storage method and pretreatment method for enhancement of the biodegradability of the crops. The efficiency of the silage process was evaluated based on (a) the amount of biomass loss during storage and (b) the effect of the silage on methane potential. Co-digestion of raw and wet explosion pretreated energy crops and agriculture residues with swine manure at various volatile solids (VS) ratio between crop and manure was carried out by batch tests and continuous experiments. The efficiency of the co-digestion experiment was evaluated based on (a) the methane potential in term of ml CH4 produced per g of VS-added and (b) the amount of methane produced per m3 of reactor volume. (Author)

  2. Elytrigia repens population dynamics under different management schemes in organic cropping systems on coarse sand

    DEFF Research Database (Denmark)

    Rasmussen, Ilse A.; Melander, Bo; Askegaard, Margrethe

    2014-01-01

    -year crop rotations including various cash crops and grass-clover leys; two rotations running during the first two courses with the one replaced with another rotation during the last course. The rotations were combined with four combinations of the treatments; with and without animal manure (‘without......Elytrigia repens is a noxious perennial weed in organic cropping systems in Scandinavia. It can easily spread in any crop type and reach unacceptable infestation levels through its proliferation from rhizome fragments. This study aimed at analyzing and quantifying the population dynamics of E....... repens recorded in a long-termed crop rotation experiment on coarse sand in Southern Denmark. The study gives an insight into the factors responsible for E. repens population changes and especially those that require particular attention to prevent outbreaks of E. repens. Data originated from three 4...

  3. Tracking Changes in Dissolved Organic Matter Patterns in Perennial Headwater Streams Throughout a Hydrologic Year Using In-situ Sensors and Optical Properties

    Science.gov (United States)

    Armstrong, A.; Epting, S.; Hosen, J. D.; Palmer, M.

    2015-12-01

    Dissolved organic matter (DOM) plays a central role in freshwater streams but key questions remain unanswered about temporal patterns in its quantity and composition. DOM in perennial streams in the temperate zone is a complex mixture reflecting a variety of sources such as leached plant material, organic matter from surrounding soils, and microbial processes in the streams themselves. Headwater perennial streams in the Tuckahoe Creek watershed of the Atlantic coastal plain (Maryland, USA) drain a mosaic of land cover types including row crops, forests, and both forested and marshy small depressional wetlands. Wetland-stream surface hydrologic connections generally occur between mid-fall and late spring, coinciding with peak wetland hydrologic expression (i.e. highest groundwater levels and surface inundation extent). When inundated, these wetlands contain high DOM concentrations, and surface connections may serve as conduits for downstream export. We hypothesized that changes in wetland-stream surface hydrologic connectivity would affect patterns of DOM concentration and composition in these streams. We deployed 6 sondes equipped with fluorescent DOM sensors in 4 perennial streams, 1 forested wetland, and the larger downstream channel draining all study sites for the 2015 water year. The 4 headwater streams drain areas containing forested wetlands and have documented temporary channel connections. Combined with baseflow and stormflow sampling, the sondes provided 15 minute estimates of dissolved organic carbon (DOC) concentrations. This resolution provided insights into patterns of DOC concentration across temporal scales from daily rhythms to seasonal changes, during both baseflow and storm conditions. Discrete measurements of absorbance and fluorescence provided information about DOM composition throughout the study. Together these measurements give a detailed record of DOM dynamics in multiple perennial headwater streams for an entire year. This information

  4. Vernalization response in perennial ryegrass (Lolium perenne L.) involves orthologues of diploid wheat (Triticum monococcum) VRN1 and rice (Oryza sativa) Hd1.

    Science.gov (United States)

    Andersen, Jeppe Reitan; Jensen, Louise Bach; Asp, Torben; Lübberstedt, Thomas

    2006-03-01

    Flowering time is important when adapting crop plants to different environments. While high feeding quality of forage grasses is facilitated by repression of flowering, flowering should also be inducible to facilitate grass seed production. Consequently, the identification and characterization of the genes controlling flowering time in forage grasses, including perennial ryegrass (Lolium perenne L.), is of great interest. In this study, three candidate genes for vernalization response genes in perennial ryegrass were identified based on DNA sequence homology to TmVRN1 and TmVRN2 of diploid wheat (Triticum monococcum), and Hd1 of rice (Oryza sativa). High sequence similarity between LpVRN1 and TmVRN1, co-localization of LpVRN1 with a major quantitative trait loci (QTL) for vernalization response in perennial ryegrass, synteny between map-positions of LpVRN1 and TmVRN1, mRNA expression analysis of LpVRN1 alleles during vernalization, and the correspondence between LpVRN1 mRNA expression levels and flowering time leads us to conclude that LpVRN1 is orthologous to TmVRN1 and that its function is conserved between diploid wheat and perennial ryegrass. Of the remaining two candidate genes, a putative Hd1 orthologue, LpCO, co-localized with a second QTL for vernlization response. LpCO has recently been shown to be involved in the photoperiodic regulation of flowering time. While epistasis, at the level of LpVRN1 transcription, was observed between the LpVRN1 and LpCO genomic regions, no differential expression of LpCO transcripts was observed during vernalization. While orthologous genes controlling flowering time can thus be identified, future allele sequencing efforts will reveal if causative polymorphisms are conserved across the grasses.

  5. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input.

    Science.gov (United States)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman; Ambus, Per; Boelt, Birte; Gislum, René

    2016-01-15

    A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N fertilizer, the forage legume pure stand, especially red clover, was able to produce about 15 t above ground dry matter ha(-1) year(-1) saving around 325 kg mineral Nfertilizer ha(-1) compared to the cocksfoot and tall fescue grass treatments. The pure stand ryegrass yielded around 3t DM more than red clover in the high fertilizer treatment. Nitrous oxide emissions were highest in the treatments containing legumes. The LCA showed that the low input N systems had markedly lower carbon footprint values than crops from the high N input system with the pure stand legumes without N fertilization having the lowest carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground production across the three-season rotation, the pure stand red clover without N application and pure stand ryegrass treatments with the highest N input equalled. The present study illustrate how leguminous biological nitrogen fixation (BNF) represents an important low impact renewable N source without reducing crop yields and thereby farmers earnings. Copyright © 2015. Published by Elsevier B.V.

  6. 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

  7. Rainfed intensive crop systems

    DEFF Research Database (Denmark)

    Olesen, Jørgen E

    2014-01-01

    This chapter focuses on the importance of intensive cropping systems in contributing to the world supply of food and feed. The impact of climate change on intensive crop production systems is also discussed....

  8. Prediction models of silage fermentation products on crop composition under strict anaerobic conditions: a meta-analysis.

    Science.gov (United States)

    Mogodiniyai Kasmaei, K; Rustas, B-O; Spörndly, R; Udén, P

    2013-10-01

    A meta-analysis was conducted to establish linkages between crop and fermentation variables. Data from well-controlled mini silage studies were used in which no additives had been used and no ingress of air had occurred. The silage set consisted of data on crop chemical composition and epiphytic lactic acid bacteria count, and fermentation products (organic acids, alcohols, and ammonia-N) from 118 silages made from 30 grass, 7 legume, 15 grass and legume mixtures, and 66 whole-crop maize samples. The prediction models for fermentation products on crop variables were obtained by stepwise multiple regression analysis. Perennial forage and maize silages were analyzed separately. The best models were obtained for acetic acid in perennial forage silages, with a coefficient of determination of 0.63, and for lactic acid and ethanol in whole-crop maize silages, with coefficients of determination of 0.84 and 0.61, respectively. Fermentation products of perennial forage and maize silages were best related to dry matter and crude protein contents, respectively. Overall, the prediction equations were weak. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. Removal of perennial herbaceous species affects response of cold desert scrublands to fire

    Science.gov (United States)

    Jeanne C. Chambers; David I. Board; Bruce A. Roundy; Peter J. Weisberg

    2017-01-01

    Our results show that loss of perennial herbaceous species, which can result from inappropriate livestock grazing, and loss of shrubs, which often results from fire, interact to affect key functional groups. The implications are that ecosystem resilience to disturbance in Cold Desert shrublands decreases when competition from perennial native grasses and forbs for...

  10. 30 CFR 780.28 - Activities in or adjacent to perennial or intermittent streams.

    Science.gov (United States)

    2010-07-01

    ... intermittent streams. 780.28 Section 780.28 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... RECLAMATION AND OPERATION PLAN § 780.28 Activities in or adjacent to perennial or intermittent streams. (a... applies to applications to conduct surface mining activities in perennial or intermittent streams or on...

  11. Transcriptional Profiling and Identification of Heat-Responsive Genes in Perennial Ryegrass by RNA-Sequencing

    Directory of Open Access Journals (Sweden)

    Kehua Wang

    2017-06-01

    Full Text Available Perennial ryegrass (Lolium perenne is one of the most widely used forage and turf grasses in the world due to its desirable agronomic qualities. However, as a cool-season perennial grass species, high temperature is a major factor limiting its performance in warmer and transition regions. In this study, a de novo transcriptome was generated using a cDNA library constructed from perennial ryegrass leaves subjected to short-term heat stress treatment. Then the expression profiling and identification of perennial ryegrass heat response genes by digital gene expression analyses was performed. The goal of this work was to produce expression profiles of high temperature stress responsive genes in perennial ryegrass leaves and further identify the potentially important candidate genes with altered levels of transcript, such as those genes involved in transcriptional regulation, antioxidant responses, plant hormones and signal transduction, and cellular metabolism. The de novo assembly of perennial ryegrass transcriptome in this study obtained more total and annotated unigenes compared to previously published ones. Many DEGs identified were genes that are known to respond to heat stress in plants, including HSFs, HSPs, and antioxidant related genes. In the meanwhile, we also identified four gene candidates mainly involved in C4 carbon fixation, and one TOR gene. Their exact roles in plant heat stress response need to dissect further. This study would be important by providing the gene resources for improving heat stress tolerance in both perennial ryegrass and other cool-season perennial grass plants.

  12. Producing bulbs and perennials : sustainable control of diseases, pests and weeds

    NARCIS (Netherlands)

    Boer, de M.

    2011-01-01

    In the Netherlands every year flower bulbs and perennials are produced representing a value of € 500 m (flower bulbs) and of € 65 m (perennials, 2004). The growers are faced with several threatening pests and diseases during the production. They usually deal with these problems by using pesticides.

  13. Considerations for Managing Agricultural Co-Existence between Transgenic and Non-Transgenic Cultivars of Outcrossing Perennial Forage Plants in Dairy Pastures

    Directory of Open Access Journals (Sweden)

    Kevin F. Smith

    2016-11-01

    Full Text Available Many of the major forage species used in agriculture are outcrossing and rely on the exchange of pollen between individuals for reproduction; this includes the major species used for dairy production in grazing systems: perennial ryegrass (Lolium perenne L. and white clover (Trifolium repens L.. Cultivars of these species have been co-existing since contrasting cultivars were developed using plant breeding, but the consequences and need for strategies to manage co-existence have been made more prominent with the advent of genetic modification. Recent technological developments have seen the experimental evaluation of genetically modified (GM white clover and perennial ryegrass, although there is no current commercial growing of GM cultivars of these species. Co-existence frameworks already exist for two major cross-pollinated grain crops (canola and maize in Europe, and for alfalfa (Medicago sativa L. in the US, so many of the principles that the industry has developed for co-existence in these crops such as detection techniques, segregation, and agronomic management provide lessons and guidelines for outcrossing forage species, that are discussed in this paper.

  14. Agronomic, Energetic and Environmental Aspects of Biomass Energy Crops Suitable for Italian Environments

    Directory of Open Access Journals (Sweden)

    Giuseppina M. D’Agosta

    2008-06-01

    Full Text Available The review, after a short introduction on the tendencies of the European Community Policy on biomasses, describes the agronomic, energy potential and environmental aspects of biomass crops for energy in relation to the research activity carried out in Italy on this topic, differentiating crops on the basis of the main energy use: biodiesel and bioethanol (which refers to “first generation biofuel”, heat and electricity. Currently, many of the crops for potential energy purposes are food crops (wheat, barley, corn, rapeseed, soybean, sunflower, grain sorghum, sugar beet and their production may be used as biofuel source (bioethanol and biodiesel since their crop management aspects are well known and consequently they are immediately applicable. Other species that could be used, highly productive in biomass, such as herbaceous perennial crops (Arundo donax, Miscanthus spp., cardoon, annual crops (sweet sorghum, short rotation woody crops (SRF have been carefully considered in Italy, but they still exhibit critical aspects related to propagation technique, low-input response, harvest and storage technique, cultivars and mechanization. Crops for food, however, often have negative energetic indices and environmental impacts (carbon sequestration, Life Cycle Assessment, consequent to their low productivity. Conversely, crops which are more productive in biomass, show both a more favourable energy balance and environmental impact.

  15. Agronomic, Energetic and Environmental Aspects of Biomass Energy Crops Suitable for Italian Environments

    Directory of Open Access Journals (Sweden)

    Giuseppina M. D’Agosta

    2011-02-01

    Full Text Available The review, after a short introduction on the tendencies of the European Community Policy on biomasses, describes the agronomic, energy potential and environmental aspects of biomass crops for energy in relation to the research activity carried out in Italy on this topic, differentiating crops on the basis of the main energy use: biodiesel and bioethanol (which refers to “first generation biofuel”, heat and electricity. Currently, many of the crops for potential energy purposes are food crops (wheat, barley, corn, rapeseed, soybean, sunflower, grain sorghum, sugar beet and their production may be used as biofuel source (bioethanol and biodiesel since their crop management aspects are well known and consequently they are immediately applicable. Other species that could be used, highly productive in biomass, such as herbaceous perennial crops (Arundo donax, Miscanthus spp., cardoon, annual crops (sweet sorghum, short rotation woody crops (SRF have been carefully considered in Italy, but they still exhibit critical aspects related to propagation technique, low-input response, harvest and storage technique, cultivars and mechanization. Crops for food, however, often have negative energetic indices and environmental impacts (carbon sequestration, Life Cycle Assessment, consequent to their low productivity. Conversely, crops which are more productive in biomass, show both a more favourable energy balance and environmental impact.

  16. Elymus repens biomass allocation and acquisition as affected by light and nutrient supply and companion crop competition.

    Science.gov (United States)

    Ringselle, Björn; Prieto-Ruiz, Inés; Andersson, Lars; Aronsson, Helena; Bergkvist, Göran

    2017-02-01

    Competitive crops are a central component of resource-efficient weed control, especially for problematic perennial weeds such as Elymus repens Competition not only reduces total weed biomass, but denial of resources can also change the allocation pattern - potentially away from the underground storage organs that make perennial weeds difficult to control. Thus, the competition mode of crops may be an important component in the design of resource-efficient cropping systems. Our aim was to determine how competition from companion crops with different modes of competition affect E. repens biomass acquisition and allocation and discuss that in relation to how E. repens responds to different levels of light and nutrient supply. Greenhouse experiments were conducted with E. repens growing in interspecific competition with increasing density of perennial ryegrass or red clover, or growing at three levels of both light and nutrient supply. Elymus repens total biomass decreased with increasing biomass of the companion crop and the rate of decrease was higher with red clover than with perennial ryegrass, particularly for E. repens rhizome biomass. A reduced nutrient supply shifted E. repens allocation towards below-ground biomass while a reduced light supply shifted it towards shoot biomass. Red clover caused no change in E. repens allocation pattern, while ryegrass mostly shifted the allocation towards below-ground biomass, but the change was not correlated with ryegrass biomass. The companion crop mode of competition influences both the suppression rate of E. repens biomass acquisition and the likelihood of shifts in E. repens biomass allocation. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Lasting mantle scars lead to perennial plate tectonics.

    Science.gov (United States)

    Heron, Philip J; Pysklywec, Russell N; Stephenson, Randell

    2016-06-10

    Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a 'perennial' phenomenon.

  18. Dynamic perennial firn aquifer on an Arctic glacier

    Science.gov (United States)

    Christianson, Knut; Kohler, Jack; Alley, Richard B.; Nuth, Christopher; Pelt, Ward J. J.

    2015-03-01

    Ice-penetrating radar and GPS observations reveal a perennial firn aquifer (PFA) on a Svalbard ice field, similar to those recently discovered in southeastern Greenland. A bright, widespread radar reflector separates relatively dry and water-saturated firn. This surface, the phreatic firn water table, is deeper beneath local surface elevation maxima, shallower in surface lows, and steeper where the surface is steep. The reflector crosscuts snow stratigraphy; we use the apparent deflection of accumulation layers due to the higher dielectric permittivity below the water table to infer that the firn pore space becomes progressively more saturated as depth increases. Our observations indicate that PFAs respond rapidly (subannually) to surface forcing, and are capable of providing significant input to the englacial hydrology system.

  19. Lasting mantle scars lead to perennial plate tectonics

    Science.gov (United States)

    Heron, Philip J.; Pysklywec, Russell N.; Stephenson, Randell

    2016-01-01

    Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a ‘perennial' phenomenon. PMID:27282541

  20. Microsatellite primers for the gynodioecious grassland perennial Saxifraga granulata (Saxifragaceae).

    Science.gov (United States)

    van der Meer, Sascha; Van Houdt, Jeroen K J; Maes, Gregory E; Hellemans, Bart; Jacquemyn, Hans

    2014-09-01

    Nine polymorphic and 12 monomorphic microsatellite loci (simple sequence repeats [SSRs]) were isolated and characterized for the gynodioecious grassland perennial Saxifraga granulata. • Based on genomic screening of leaf material of four individuals from four populations, a total of 21 microsatellite primer pairs were designed for S. granulata. Nine loci were polymorphic and were optimized into two PCR multiplex reactions and tested on 100 individuals from five riparian populations from central Belgium. The number of alleles of the polymorphic loci ranged from three to 18, and gametic heterozygosity ranged from 0.26 to 0.94. • The markers that are presented here are the first microsatellite markers reported for S. granulata and will be used to assess how river systems shape the spatial genetic structure and diversity of riparian populations of this species.

  1. Microsatellite Primers for the Gynodioecious Grassland Perennial Saxifraga granulata (Saxifragaceae

    Directory of Open Access Journals (Sweden)

    Sascha van der Meer

    2014-08-01

    Full Text Available Premise of the study: Nine polymorphic and 12 monomorphic microsatellite loci (simple sequence repeats [SSRs] were isolated and characterized for the gynodioecious grassland perennial Saxifraga granulata. Methods and Results: Based on genomic screening of leaf material of four individuals from four populations, a total of 21 microsatellite primer pairs were designed for S. granulata. Nine loci were polymorphic and were optimized into two PCR multiplex reactions and tested on 100 individuals from five riparian populations from central Belgium. The number of alleles of the polymorphic loci ranged from three to 18, and gametic heterozygosity ranged from 0.26 to 0.94. Conclusions: The markers that are presented here are the first microsatellite markers reported for S. granulata and will be used to assess how river systems shape the spatial genetic structure and diversity of riparian populations of this species.

  2. Coordinated Expression of Functionally Diverse Fructosyltransferase Genes Is Associated with Fructan Accumulation in Response to Low Temperature in Perennial Ryegrass

    National Research Council Canada - National Science Library

    Hiroshi Hisano; Akira Kanazawa; Midori Yoshida; Mervyn O. Humphreys; Masaru Iizuka; Keisuke Kitamura; Toshihiko Yamada

    2008-01-01

    ...) genes in perennial ryegrass (Lolium perenne) are described. Six cDNAs (prft1-prft6) encoding FTs were isolated from cold-treated ryegrass plants, and three were positioned on a perennial ryegrass linkage map...

  3. Summary appraisals of the Nation's ground-water resources; California region

    Science.gov (United States)

    Thomas, H.E.; Phoenix, D.A.

    1976-01-01

    Most people in the California Region live in a semiarid or arid climate, with precipitation less than the potential evapotranspiration- environments of perennial water deficiency. The deficiency becomes most onerous during the characteristically rainless summers and during recurrent droughts that may continue for 10--20 years. However, water from winter rain and snow can be stored for use during the dry summer months, and water stored during a wet climatic period can be used in a succeeding dry period; moreover, perennial deficiency can be overcome by bringing water from areas of perennial surplus. Ground-water reservoirs have especial significance in arid and semiarid regions as repositories where water is stored or can be stored with minimum loss by evaporation.

  4. Site-adapted cultivation of bioenergy crops - a strategy towards a greener and innovative feedstock production

    Science.gov (United States)

    Ruf, Thorsten; Emmerling, Christoph

    2017-04-01

    Cultivation of bioenergy crops is of increasing interest to produce valuable feedstocks e.g. for anaerobic digestion. In the past decade, the focus was primarily set to cultivation of the most economic viable crop, namely maize. In Germany for example, the cultivation area of maize was expanded from approx. 200,000 ha in 2006 to 800,000 ha in 2015. However, this process initiated a scientific and public discussion about the sustainability of intense maize cultivation. Concerns addressed in this context are depletion of soil organic matter, soil erosion and compaction as well as losses of (agro-)biodiversity. However, from a soil science perspective, several problems arise from not site-adapted cultivation of maize. In contrast, the cultivation of perennial bioenergy crops may provide a valuable opportunity to preserve or even enhance soil fertility and agrobiodiversity without limiting economic efficiency. Several perennial energy crops, with various requirements regarding stand conditions, allow a beneficial selection of the most suitable species for a respective location. The study aimed to provide a first step towards a more strategic planning of bioenergy crop cultivation with respect to spatial arrangement, distribution and connectivity of sites on a regional scale. The identification of pedological site characteristics is a crucial step in this process. With the study presented, we tried to derive site information that allow for an assessment of the suitability for specific energy crops. Our idea is to design a multifunctional landscape with a coexistence of sites with reduced management for soil protection and highly productive site. By a site adapted cultivation of perennial energy plants in sensitive areas, a complex, heterogeneous landscape could be reached.

  5. Determinants of crop diversity and composition in Enset-coffee agroforestry homegardens of Southern Ethiopia

    Directory of Open Access Journals (Sweden)

    Tesfaye Abebe

    2013-08-01

    Full Text Available Households in much of the tropics depend for their livelihoods on the variety and continued production of food and other products that are provided by their own farms. In such systems, maintenance of agrobiodiversity and ensuring food security are important for the well being of the population. The enset-coffee agroforestry homegardens of Southern Ethiopia that are dominated by two native perennial crops, Coffee (Coffea arabica L. and Enset (Enset ventricosum Welw. Cheesman, are examples of such agricultural systems. This study was conducted in Sidama administrative zone of Southern Ethiopia to determine the factors that influence the diversity and composition of crops in the systems. Data were collected from 144 sample homegardens selected from four districts. Stepwise multiple regression analysis was used to relate indices of crop diversity and area share of major crops with the physical and socioeconomic factors. The study revealed that socioeconomic factors, mainly proximity to markets, affected negatively crop species richness. The production area of the main crops enset and coffee decreased with increasing proximity to market and road while that of maize and khat increased. At household level, farm size had a significant effect on area share of enset and coffee. As farm size increased the share of the cash crop, coffee increased but that of the staple, enset declined. Enset, which is the backbone of the system in terms of food security, is declining on small farms and the share of monoculture maize system is increasing. The trend towards declining agrobiodiversity, and reduction in the production area of the main perennial crops and their gradual replacement with monoculture fields could make the systems liable to instability and collapse. As these sites are high potential agricultural areas, intensification can be achieved by integrating high-value and more productive crops, such as fruits, spices and vegetables, while maintaining the

  6. Energy embodiment in Brazilian agriculture: an overview of 23 crops

    Directory of Open Access Journals (Sweden)

    João Paulo Soto Veiga

    2015-12-01

    Full Text Available The amount of energy required to produce a commodity or to supply a service varies from one production system to another and consequently giving rise to differing levels of environmental efficiency. Moreover, since energy prices have been continuously increasing over time, this energy amount may be a factor that has economic worth. Biomass production has a variety of end-products such as food, energy, and fiber; thus, taking into account the similarity in end-product of different crops (e.g.: sunflower, peanuts, or soybean for oil it is possible to evaluate which crops require less energy per functional unit, such as starch, oil, and protein. This information can be used in decision-making about policies for food safety or bioenergy. In this study, 23 crops were evaluated allowing for a comparison in terms of energy embodied per functional unit. Crops were grouped as follows: starch, oil, horticultural, perennial and fiber, to provide for a deeper analysis of alternatives for the groups, and subsidize further studies comparing conventional and alternative production systems such as organic or genetically modified organisms, in terms of energy. The best energy balance observed was whole sugarcane (juice, bagasse and straw with a surplus of 268 GJ ha−1 yr−1; palm shows the highest energy return on investment with a ratio of approximately 30:1. For carbohydrates and protein production, cassava and soybean, respectively, emerged as the crops offering the greatest energy savings in the production of these functional foods.

  7. 30 CFR 817.57 - Hydrologic balance: Surface activities in or adjacent to perennial or intermittent streams.

    Science.gov (United States)

    2010-07-01

    ... adjacent to perennial or intermittent streams. 817.57 Section 817.57 Mineral Resources OFFICE OF SURFACE... activities in or adjacent to perennial or intermittent streams. (a)(1) Buffer requirement. Except as provided... feet, measured horizontally, of a perennial or intermittent stream, unless the regulatory authority...

  8. Nitrogen release from differently aged Raphanus sativus L. nitrate catch crops during mineralization at autumn temperatures

    DEFF Research Database (Denmark)

    Thomsen, Ingrid Kaag; Elsgaard, Lars; Olesen, Jørgen Eivind

    2016-01-01

    radish (Raphanus sativus, L.) has emerged as a promising nitrate catch crop in cereal cropping, although the course of remineralization of residue N following termination of this frost-sensitive crucifer remains obscured. We incubated radish residues of different age (different planting and harvest dates......) with a loamy sand soil; mineralization of residue N was determined after 1, 2, 4 and 7 months of incubation at 2 °C and 10 °C. Incubations with soil only and with residues of white mustard (Sinapis alba, L) and perennial ryegrass (Lolium perenne, L.) were included as references. Using linear regression, net N...

  9. Annual grasses in crop rotations with grass seed production - A survey with special focus on Vulpia spp. in red fescue production

    DEFF Research Database (Denmark)

    Jensen, Peter Kryger; Kristensen, Kristian

    2013-01-01

    in the field. The survey showed that Poa annua, Elytrigia repens and Poa trivialis were the three most frequent grass weeds in grass seed crops. Furthermore, Bromus hordeaceus, Bromus sterilis, P. trivialis and Vulpia spp. showed an increasing frequency in the study period. The perennial weed, E. repens...

  10. Estimating legume N-2 fixation in grass-clover mixtures of a grazed organic cropping system using two N-15 methods

    DEFF Research Database (Denmark)

    Vinther, F.P.; Jensen, E.S.

    2000-01-01

    The input of Nitrogen (N) through symbiotic N-2 fixation (SNF) in grass-clover mixtures was determined in an organic cropping. system for grazing during 3 years. The mixture of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) was established by undersowing in spring...

  11. Transcriptome analysis in sheepgrass (Leymus chinensis: a dominant perennial grass of the Eurasian Steppe.

    Directory of Open Access Journals (Sweden)

    Shuangyan Chen

    Full Text Available BACKGROUND: Sheepgrass [Leymus chinensis (Trin. Tzvel.] is an important perennial forage grass across the Eurasian Steppe and is known for its adaptability to various environmental conditions. However, insufficient data resources in public databases for sheepgrass limited our understanding of the mechanism of environmental adaptations, gene discovery and molecular marker development. RESULTS: The transcriptome of sheepgrass was sequenced using Roche 454 pyrosequencing technology. We assembled 952,328 high-quality reads into 87,214 unigenes, including 32,416 contigs and 54,798 singletons. There were 15,450 contigs over 500 bp in length. BLAST searches of our database against Swiss-Prot and NCBI non-redundant protein sequences (nr databases resulted in the annotation of 54,584 (62.6% of the unigenes. Gene Ontology (GO analysis assigned 89,129 GO term annotations for 17,463 unigenes. We identified 11,675 core Poaceae-specific and 12,811 putative sheepgrass-specific unigenes by BLAST searches against all plant genome and transcriptome databases. A total of 2,979 specific freezing-responsive unigenes were found from this RNAseq dataset. We identified 3,818 EST-SSRs in 3,597 unigenes, and some SSRs contained unigenes that were also candidates for freezing-response genes. Characterizations of nucleotide repeats and dominant motifs of SSRs in sheepgrass were also performed. Similarity and phylogenetic analysis indicated that sheepgrass is closely related to barley and wheat. CONCLUSIONS: This research has greatly enriched sheepgrass transcriptome resources. The identified stress-related genes will help us to decipher the genetic basis of the environmental and ecological adaptations of this species and will be used to improve wheat and barley crops through hybridization or genetic transformation. The EST-SSRs reported here will be a valuable resource for future gene-phenotype studies and for the molecular breeding of sheepgrass and other Poaceae species.

  12. Transcriptome Analysis in Sheepgrass (Leymus chinensis). A Dominant Perennial Grass of the Eurasian Steppe

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shuangyan [Chinese Academy of Sciences (CAS), Institute of Botany (IB), Beijing; Huang, Xin [Chinese Academy of Sciences (CAS), Institute of Botany (IB), Beijing; Yang, Xiaohan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Gongshe [Chinese Academy of Sciences (CAS), Institute of Botany (IB), Beijing

    2013-07-04

    BACKGROUND: Sheepgrass [Leymus chinensis (Trin.) Tzvel.] is an important perennial forage grass across the Eurasian Steppe and is known for its adaptability to various environmental conditions. However, insufficient data resources in public databases for sheepgrass limited our understanding of the mechanism of environmental adaptations, gene discovery and molecular marker development. RESULTS: The transcriptome of sheepgrass was sequenced using Roche 454 pyrosequencing technology. We assembled 952,328 high-quality reads into 87,214 unigenes, including 32,416 contigs and 54,798 singletons. There were 15,450 contigs over 500 bp in length. BLAST searches of our database against Swiss-Prot and NCBI non-redundant protein sequences (nr) databases resulted in the annotation of 54,584 (62.6%) of the unigenes. Gene Ontology (GO) analysis assigned 89,129 GO term annotations for 17,463 unigenes. We identified 11,675 core Poaceae-specific and 12,811 putative sheepgrass-specific unigenes by BLAST searches against all plant genome and transcriptome databases. A total of 2,979 specific freezing-responsive unigenes were found from this RNAseq dataset. We identified 3,818 EST-SSRs in 3,597 unigenes, and some SSRs contained unigenes that were also candidates for freezing-response genes. Characterizations of nucleotide repeats and dominant motifs of SSRs in sheepgrass were also performed. Similarity and phylogenetic analysis indicated that sheepgrass is closely related to barley and wheat. CONCLUSIONS: This research has greatly enriched sheepgrass transcriptome resources. The identified stress-related genes will help us to decipher the genetic basis of the environmental and ecological adaptations of this species and will be used to improve wheat and barley crops through hybridization or genetic transformation. The EST-SSRs reported here will be a valuable resource for future gene-phenotype studies and for the molecular breeding of sheepgrass and other Poaceae species.

  13. Transcriptome analysis in sheepgrass (Leymus chinensis): a dominant perennial grass of the Eurasian Steppe.

    Science.gov (United States)

    Chen, Shuangyan; Huang, Xin; Yan, Xueqing; Liang, Ye; Wang, Yuezhu; Li, Xiaofeng; Peng, Xianjun; Ma, Xingyong; Zhang, Lexin; Cai, Yueyue; Ma, Tian; Cheng, Liqin; Qi, Dongmei; Zheng, Huajun; Yang, Xiaohan; Li, Xiaoxia; Liu, Gongshe

    2013-01-01

    Sheepgrass [Leymus chinensis (Trin.) Tzvel.] is an important perennial forage grass across the Eurasian Steppe and is known for its adaptability to various environmental conditions. However, insufficient data resources in public databases for sheepgrass limited our understanding of the mechanism of environmental adaptations, gene discovery and molecular marker development. The transcriptome of sheepgrass was sequenced using Roche 454 pyrosequencing technology. We assembled 952,328 high-quality reads into 87,214 unigenes, including 32,416 contigs and 54,798 singletons. There were 15,450 contigs over 500 bp in length. BLAST searches of our database against Swiss-Prot and NCBI non-redundant protein sequences (nr) databases resulted in the annotation of 54,584 (62.6%) of the unigenes. Gene Ontology (GO) analysis assigned 89,129 GO term annotations for 17,463 unigenes. We identified 11,675 core Poaceae-specific and 12,811 putative sheepgrass-specific unigenes by BLAST searches against all plant genome and transcriptome databases. A total of 2,979 specific freezing-responsive unigenes were found from this RNAseq dataset. We identified 3,818 EST-SSRs in 3,597 unigenes, and some SSRs contained unigenes that were also candidates for freezing-response genes. Characterizations of nucleotide repeats and dominant motifs of SSRs in sheepgrass were also performed. Similarity and phylogenetic analysis indicated that sheepgrass is closely related to barley and wheat. This research has greatly enriched sheepgrass transcriptome resources. The identified stress-related genes will help us to decipher the genetic basis of the environmental and ecological adaptations of this species and will be used to improve wheat and barley crops through hybridization or genetic transformation. The EST-SSRs reported here will be a valuable resource for future gene-phenotype studies and for the molecular breeding of sheepgrass and other Poaceae species.

  14. Importance and condition of forage crops seed production in agriculture of the Republic of Serbia

    Directory of Open Access Journals (Sweden)

    Đokić Dragoslav

    2013-01-01

    Full Text Available For contemporary and economical livestock production, especially cattle and sheep raising, it is necessary to achieve high production of livestock feed while reducing production costs. Improving the production of perennial grasses and legumes creates a good basis for the development of livestock production in different agro-ecological conditions of Serbia. It also establishes a link between farming and animal husbandry, which is of particular importance for the preservation and higher fertility of arable land and the protection of agro-ecosystems. An important factor for the cheaper production of livestock feed is the possibility to provide sufficient quantities of quality seeds at affordable prices. Production of quality seeds of local varieties of perennial legumes is possible to obtain sufficient amounts of good quality forage. Current situation in forage crop seed production of the Republic of Serbia is unsatisfactory because the seed of perennial grasses are mostly imported. Domestic production of alfalfa, red clover and birdsfoot trefoil met domestic needs only in some years. Seed of imported varieties are often not satisfactory because those varieties are not adapted to our local agro-ecological conditions. The present results provide the basis and direction for further researches that may provide solutions to increase seed yields and which will be widely accepted in practice, which will make the production more cost-effective. Institute for forage crops Kruševac is making a significant contribution to the development of technology of seed productions, especially alfalfa, red clover and perennial grasses. Therefore the role of the Institute is very important and necessary link between production, processing and trading seeds of perennial legumes and grasses in Serbia.

  15. Managed Multi-strata Tree + Crop Systems: An Agroecological Marvel

    Directory of Open Access Journals (Sweden)

    P. K. Ramachandran Nair

    2017-12-01

    Full Text Available Today, when the emphasis on single-species production systems that is cardinal to agricultural and forestry programs the world over has resulted in serious ecosystem imbalances, the virtues of the time-tested practice of growing different species together as in managed Multi-strata Tree + Crop (MTC systems deserve serious attention. The coconut-palm-based multispecies systems in tropical homegardens and shaded perennial systems are just two such systems. A fundamental ecological principle of these systems is niche complementarity, which implies that systems that are structurally and functionally more complex than crop- or tree monocultures result in greater efficiency of resource (nutrients, light, and water capture and utilization. Others include spatial and temporal heterogeneity, perennialism, and structural and functional diversity. Unexplored or under-exploited areas of benefits of MTC systems include their ecosystem services such as carbon storage, climate regulation, and biodiversity conservation. These multispecies integrated systems indeed represent an agroecological marvel, the principles of which could be utilized in the design of sustainable as well as productive agroecosystems. Environmental and ecological specificity of MTC systems, however, is a unique feature that restricts their comparison with other land-use systems and extrapolation of the management features used in one location to another.

  16. Cropping systems and control of soil erosion in a Mediterranean environment

    Science.gov (United States)

    Cosentino, Salvatore; Copani, Venera; Testa, Giorgio; Scalici, Giovanni

    2013-04-01

    The research has been carried out over the years 1996-2010 in an area of the internal hill of Sicily region (Enna, c.da Geracello, 550 m a. s. l. 37° 23' N. Lat, 14° 21' E. Long) in the center of Mediterranean Sea, mainly devoted to durum wheat cultivation, using the experimental plots, established in 1996 on a slope of 26-28%, equipped to determine surface runoff and soil losses. The establishment consists of twelve plots, having 40 m length and 8 m width. In order to study the effect of different field crop systems in controlling soil erosion in slopes subjected to water erosion, the following systems were studied: permanent crops, tilled annual crops, no-tilled annual crops, set-aside. The used crops were: durum wheat, faba bean, rapeseed, subterranean clover, Italian ryegrass, alfalfa, sweetvetch, moon trefoil, barley, sweet sorghum, sunflower. The results pointed out that the cropping systems with perennial crops allowed to keep low the soil loss, while annual crop rotation determined a high amount of soil loss. Sod seeding showed promising results also for annual crop rotations.

  17. Stream Health Sensitivity to Landscape Changes due to Bioenergy Crops Expansion

    Science.gov (United States)

    Nejadhashemi, A.; Einheuser, M. D.; Woznicki, S. A.

    2012-12-01

    Global demand for bioenergy has increased due to uncertainty in oil markets, environmental concerns, and expected increases in energy consumption worldwide. To develop a sustainable biofuel production strategy, the adverse environmental impacts of bioenergy crops expansion should be understood. To study the impact of bioenergy crops expansion on stream health, the adaptive neural-fuzzy inference system (ANFIS) was used to predict macroinvertebrate and fish stream health measures. The Hilsenhoff Biotic Index (HBI), Family Index of Biological Integrity (Family IBI), and Number of Ephemeroptera, Plecoptera, and Trichoptera taxa (EPT taxa) were used as macroinvertebrate measures, while the Index of Biological Integrity (IBI) was used for fish. A high-resolution biophysical model built using the Soil and Water Assessment Tool was used to obtain water quantity and quality variables for input into the ANFIS stream health predictive models. Twenty unique crop rotations were developed to examine impacts of bioenergy crops expansion on stream health in the Saginaw Bay basin. Traditional intensive row crops generated more pollution than current landuse conditions, while second-generation biofuel crops associated with less intensive agricultural activities resulted in water quality improvement. All three macroinvertebrate measures were negatively impacted during intensive row crop productions but improvement was predicted when producing perennial crops. However, the expansion of native grass, switchgrass, and miscanthus production resulted in reduced IBI relative to first generation row crops. This study demonstrates that ecosystem complexity requires examination of multiple stream health measures to avoid potential adverse impacts of landuse change on stream health.

  18. Whole Farm Net Greenhouse Gas Abatement from Establishing Kikuyu-Based Perennial Pastures in South-Western Australia

    Directory of Open Access Journals (Sweden)

    David G. Masters

    2012-08-01

    Full Text Available On-farm activities that reduce GHG emissions or sequester carbon from the atmosphere to compensate for anthropogenic emissions are currently being evaluated by the Australian Government as carbon offset opportunities. The aim of this study was to examine the implications of establishing and grazing Kikuyu pastures, integrated as part of a mixed Merino sheep and cropping system, as a carbon offset mechanism. For the assessment of changes in net greenhouse gas emissions, results from a combination of whole farm economic and livestock models were used (MIDAS and GrassGro. Net GHG emissions were determined by deducting increased emissions from introducing this practice change (increased methane and nitrous oxide emissions due to higher stocking rates from the soil carbon sequestered from growing the Kikuyu pasture. Our results indicate that livestock systems using perennial pastures may have substantially lower net GHG emissions, and reduced GHG intensity of production, compared with annual plant-based production systems. Soil carbon accumulation by converting 45% of arable land within a farm enterprise to Kikuyu-based pasture was determined to be 0.80 t CO2-e farm ha−1 yr−1 and increased GHG emissions (leakage was 0.19 t CO2-e farm ha−1 yr−1. The net benefit of this practice change was 0.61 t CO2-e farm ha−1 yr−1 while the rate of soil carbon accumulation remains constant. The use of perennial pastures improved the efficiency of animal production almost eight fold when expressed as carbon dioxide equivalent emissions per unit of animal product. The strategy of using perennial pasture to improve production levels and store additional carbon in the soil demonstrates how livestock should be considered in farming systems as both sources and sinks for GHG abatement.

  19. Climate protection and energy crops. Potential for greenhouse gas emission reduction through crop rotation and crop planning; Klimaschutz und Energiepflanzenanbau. Potenziale zur Treibhausgasemissionsminderung durch Fruchtfolge- und Anbauplanung

    Energy Technology Data Exchange (ETDEWEB)

    Eckner, Jens [Thueringer Landesanstalt fuer Landwirtschaft (Germany); Peter, Christiane; Vetter, Armin

    2015-07-01

    The EVA project compares nationwide energy crops and crop rotations on site-specific productivity. In addition to agronomic suitability for cultivation economic and environmental benefits and consequences are analyzed and evaluated. As part of sustainability assessment of the tested cultivation options LCAs are established. The model MiLA developed in the project uses empirical test data and site parameters to prepare the inventory balances. At selected locations different cultivation and fertilization regimes are examined comparatively. In the comparison of individual crops and crop rotation combinations cultivation of W.Triticale-GPS at the cereals favor location Dornburg causes the lowest productrelated GHG-emissions. Due to the efficient implementation of nitrogen and the substrate properties of maize is the cultivation despite high area-related emissions and N-expenses at a low level of emissions. Because of the intensity the two culture systems offer lower emissions savings potentials with high area efficiency. Extensification with perennial alfalfagrass at low nitrogen effort and adequate yield performance show low product-related emissions. Closing the nutrient cycles through a recirculation of digestates instead of using mineral fertilization has a climate-friendly effect. Adapted intensifies of processing or reduced tillage decrease diesel consumption and their related emissions.

  20. Miscanthus: A Review of European Experience with a Novel Energy Crop

    Energy Technology Data Exchange (ETDEWEB)

    Scurlock, J.M.O.

    1999-02-01

    Miscanthus is a tall perennial grass which has been evaluated in Europe over the past 5-10 years as a new bioenergy crop. The sustained European interest in miscanthus suggests that this novel energy crop deserves serious investigation as a possible candidate biofuel crop for the US alongside switchgrass. To date, no agronomic trials or trial results for miscanthus are known from the conterminous US, so its performance under US conditions is virtually unknown. Speculating from European data, under typical agricultural practices over large areas, an average of about 8t/ha (3t/acre dry weight) may be expected at harvest time. As with most of the new bioenergy crops, there seems to be a steep ''learning curve.'' Establishment costs appear to be fairly high at present (a wide range is reported from different European countries), although these may be expected to fall as improved management techniques are developed.

  1. Fast-cycling unit of root turnover in perennial herbaceous plants in a cold temperate ecosystem

    OpenAIRE

    Kai Sun; M. Luke McCormack; Le Li; Zeqing Ma; Dali Guo

    2016-01-01

    Roots of perennial plants have both persistent portion and fast-cycling units represented by different levels of branching. In woody species, the distal nonwoody branch orders as a unit are born and die together relatively rapidly (within 1?2 years). However, whether the fast-cycling units also exist in perennial herbs is unknown. We monitored root demography of seven perennial herbs over two years in a cold temperate ecosystem and we classified the largest roots on the root collar or rhizome...

  2. Municipal sludge as source of nitrogen and phosphorus in perennial ...

    African Journals Online (AJOL)

    Land application of sludge has been shown to improve soil properties and aid crop growth, but the possibility of constituent nutrients such as nitrogen and phosphorus reaching environmentally toxic levels has caused governing authorities ... The treatments consisted of 0, 4, 8 and 16 Mg∙ha-1 anaerobically digested sludge.

  3. California Political Districts

    Data.gov (United States)

    California Department of Resources — This is a series of district layers pertaining to California'spolitical districts, that are derived from the California State Senateand State Assembly information....

  4. Were lakes on early Mars perennially were ice-covered?

    Science.gov (United States)

    Sumner, D. Y.; Rivera-Hernandez, F.; Mackey, T. J.

    2016-12-01

    Paleo-lake deposits indicate that Mars once sustained liquid water, supporting the idea of an early "wet and warm" Mars. However, liquid water can be sustained under ice in cold conditions as demonstrated by perennially ice-covered lakes (PICLs) in Antarctica. If martian lakes were ice-covered, the global climate on early Mars could have been much colder and dryer than if the atmosphere was in equilibrium with long-lived open water lakes. Modern PICLs on Earth have diagnostic sedimentary features. Unlike open water lakes that are dominated by mud, and drop stones or tills if icebergs are present, previous studies determined that deposits in PICLs can include coarser grains that are transported onto the ice cover, where they absorb solar radiation, melt through the ice and are deposited with lacustrine muds. In Lake Hoare, Antarctica, these coarse grains form conical sand mounds and ridges. Our observations of ice-covered lakes Joyce, Fryxell, Vanda and Hoare, Antarctica suggest that the distributions of grains depend significantly on ice characteristics. Deposits in these lakes contain moderately well to moderately sorted medium to very coarse sand grains, which preferentially melt through the ice whereas granules and larger grains remain on the ice surface. Similarly, high albedo grains are concentrated on the ice surface, whereas low albedo grains melt deeper into the ice, demonstrating a segregation of grains due to ice-sediment interactions. In addition, ice cover thickness may determine the spatial distribution of sand deposited in PICLs. Localized sand mounds and ridges composed of moderately sorted sand are common in PICLs with rough ice covers greater than 3 m thick. In contrast, lakes with smooth and thinner ice have disseminated sand grains and laterally extensive sand layers but may not have sand mounds. At Gale Crater, Mars, the Murray formation consists of sandy lacustrine mudstones, but the depositional process for the sand is unknown. The presence of

  5. Alternative scenarios of bioenergy crop production in an agricultural landscape and implications for bird communities.

    Science.gov (United States)

    Blank, Peter J; Williams, Carol L; Sample, David W; Meehan, Timothy D; Turner, Monica G

    2016-01-01

    Increased demand and government mandates for bioenergy crops in the United States could require a large allocation of agricultural land to bioenergy feedstock production and substantially alter current landscape patterns. Incorporating bioenergy landscape design into land-use decision making could help maximize benefits and minimize trade-offs among alternative land uses. We developed spatially explicit landscape scenarios of increased bioenergy crop production in an 80-km radius agricultural landscape centered on a potential biomass-processing energy facility and evaluated the consequences of each scenario for bird communities. Our scenarios included conversion of existing annual row crops to perennial bioenergy grasslands and conversion of existing grasslands to annual bioenergy row crops. The scenarios explored combinations of four biomass crop types (three potential grassland crops along a gradient of plant diversity and one annual row crop [corn]), three land conversion percentages to bioenergy crops (10%, 20%, or 30% of row crops or grasslands), and three spatial configurations of biomass crop fields (random, clustered near similar field types, or centered on the processing plant), yielding 36 scenarios. For each scenario, we predicted the impact on four bird community metrics: species richness, total bird density, species of greatest conservation need (SGCN) density, and SGCN hotspots (SGCN birds/ha ≥ 2). Bird community metrics consistently increased with conversion of row crops to bioenergy grasslands and consistently decreased with conversion of grasslands to bioenergy row crops. Spatial arrangement of bioenergy fields had strong effects on the bird community and in some cases was more influential than the amount converted to bioenergy crops. Clustering grasslands had a stronger positive influence on the bird community than locating grasslands near the central plant or at random. Expansion of bioenergy grasslands onto marginal agricultural lands will

  6. Crop Breeding Chips and Genotyping Platforms: Progress, Challenges, and Perspectives.

    Science.gov (United States)

    Rasheed, Awais; Hao, Yuanfeng; Xia, Xianchun; Khan, Awais; Xu, Yunbi; Varshney, Rajeev K; He, Zhonghu

    2017-08-07

    There is a rapidly rising trend in the development and application of molecular marker assays for gene mapping and discovery in field crops and trees. Thus far, more than 50 SNP arrays and 15 different types of genotyping-by-sequencing (GBS) platforms have been developed in over 25 crop species and perennial trees. However, much less effort has been made on developing ultra-high-throughput and cost-effective genotyping platforms for applied breeding programs. In this review, we discuss the scientific bottlenecks in existing SNP arrays and GBS technologies and the strategies to develop targeted platforms for crop molecular breeding. We propose that future practical breeding platforms should adopt automated genotyping technologies, either array or sequencing based, target functional polymorphisms underpinning economic traits, and provide desirable prediction accuracy for quantitative traits, with universal applications under wide genetic backgrounds in crops. The development of such platforms faces serious challenges at both the technological level due to cost ineffectiveness, and the knowledge level due to large genotype-phenotype gaps in crop plants. It is expected that such genotyping platforms will be achieved in the next ten years in major crops in consideration of (a) rapid development in gene discovery of important traits, (b) deepened understanding of quantitative traits through new analytical models and population designs, (c) integration of multi-layer -omics data leading to identification of genes and pathways responsible for important breeding traits, and (d) improvement in cost effectiveness of large-scale genotyping. Crop breeding chips and genotyping platforms will provide unprecedented opportunities to accelerate the development of cultivars with desired yield potential, quality, and enhanced adaptation to mitigate the effects of climate change. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  7. [Ficus benjamina, a perennial inhalation allergen of increasing importance].

    Science.gov (United States)

    Bircher, A J; Wüthrich, B; Langauer, S; Schmid, P

    1993-06-05

    12 patients are described with perennial allergic rhinoconjunctivitis or asthma, 3 had additionally urticarial eruptions and one edema of the eyelids. In all of them sensitization to Ficus benjamina was identified by skin prick tests, in 7 cases by the additional presence of specific IgE in vitro, and in 2 it was verified by a conjunctival provocation test. 10 patients were atopic with sensitization to other respiratory allergens such as pollen, house dust mite or animal dander. 2 patients, however, with a massive exposure to Ficus benjamina at home, were non-atopic with monovalent sensitization to this plant. Ficus benjamina is a tropical tree of the genus Ficus which belongs to the Moraceae family. The allergen is located in the plant sap, the so called latex, which after evaporation binds to dust particles on the leaf surface. Upon contact they are emanated from the leaves, thus imitating allergy to house dust components. Since Ficus benjamina is a very popular decorative plant, an increasing number of sensitized individuals is to be expected. The identification of a preventable respiratory allergen is of considerable importance for the patients.

  8. Contrasting effects of spatial heterogeneity and environmental stochasticity on population dynamics of a perennial wildflower

    National Research Council Canada - National Science Library

    Crone, Elizabeth E; Griffith, Alden

    2016-01-01

    ... (spatial heterogeneity) are less clearly defined. I evaluated the effects of spatial and temporal variation on the population dynamics of Pulsatilla patens , pasqueflower, a perennial prairie forb. I conducted a 10...

  9. Genomics-Assisted Exploitation of Heterosis in Perennial Ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Islam, Md. Shofiqul

    Perennial ryegrass (Lolium perenne L.) is the most important forage and turf grass species of temperate regions worldwide, and its main role is to provide feed to livestock. The economic value of perennial ryegrass is measured by its end products such as meat and milk. As an allogamous species...... ryegrass for the development of improved varieties. During his PhD studies, Mohammad Shofiqul Islam studied the feasibility of developing novel hybrid breeding schemes based on cytoplasmic male sterility (CMS) systems in perennial ryegrass. He successfully completed the assembly and annotation of a male......-fertile perennial ryegrass mitochondrial genome, and identified candidate genes responsible for the CMS phenotype by comparing male-fertile and male-sterile mitochondrial genomes. His findings constitute a good basis for continuing research to produce hybrid grass varieties to address the future needs...

  10. Genetic identity and diversity of perennial pepperweed (Lepidium latifolium) in its native and invaded ranges

    Science.gov (United States)

    Perennial pepperweed is an invasive plant species in North America, native to temperate Eurasia and northern Africa. Effective biological control depends upon correct taxonomic identification. Therefore, we investigated morphological and genetic data (DNA sequences and Amplified Fragment Length Poly...

  11. Allometric Models for Predicting Aboveground Biomass and Carbon Stock of Tropical Perennial C4 Grasses in Hawaii

    Directory of Open Access Journals (Sweden)

    Adel H. Youkhana

    2017-05-01

    Full Text Available Biomass is a promising renewable energy option that provides a more environmentally sustainable alternative to fossil resources by reducing the net flux of greenhouse gasses to the atmosphere. Yet, allometric models that allow the prediction of aboveground biomass (AGB, biomass carbon (C stock non-destructively have not yet been developed for tropical perennial C4 grasses currently under consideration as potential bioenergy feedstock in Hawaii and other subtropical and tropical locations. The objectives of this study were to develop optimal allometric relationships and site-specific models to predict AGB, biomass C stock of napiergrass, energycane, and sugarcane under cultivation practices for renewable energy and validate these site-specific models against independent data sets generated from sites with widely different environments. Several allometric models were developed for each species from data at a low elevation field on the island of Maui, Hawaii. A simple power model with stalk diameter (D was best related to AGB and biomass C stock for napiergrass, energycane, and sugarcane, (R2 = 0.98, 0.96, and 0.97, respectively. The models were then tested against data collected from independent fields across an environmental gradient. For all crops, the models over-predicted AGB in plants with lower stalk D, but AGB was under-predicted in plants with higher stalk D. The models using stalk D were better for biomass prediction compared to dewlap H (Height from the base cut to most recently exposed leaf dewlap models, which showed weak validation performance. Although stalk D model performed better, however, the mean square error (MSE-systematic was ranged from 23 to 43 % of MSE for all crops. A strong relationship between model coefficient and rainfall was existed, although these were irrigated systems; suggesting a simple site-specific coefficient modulator for rainfall to reduce systematic errors in water-limited areas. These allometric equations

  12. Landscape patterns of bioenergy in a changing climate: implications for crop allocation and land-use competition.

    Science.gov (United States)

    Graves, Rose A; Pearson, Scott M; Turner, Monica G

    2016-03-01

    Rural landscapes face changing climate, shifting development pressure, and loss of agricultural land. Perennial bioenergy crops grown on existing agricultural land may provide an opportunity to conserve rural landscapes while addressing increased demand for biofuels. However, increased bioenergy production and changing land use raise concerns for tradeoffs within the food-energy-environment trilemma. Heterogeneity of climate, soils, and land use complicate assessment of bioenergy potential in complex landscapes, creating challenges to evaluating future tradeoffs. The hypothesis addressed herein is that perennial bioenergy production can provide an opportunity to avoid agricultural land conversion to development. Using a process-based crop model, we assessed potential bioenergy crop growth through 2100 in a southern Appalachian Mountain region and asked: (1) how mean annual yield differed among three crops (switchgrass Panicum virgatum, giant miscanthus Miscanthus x giganteus, and hybrid poplar Populus x sp.) under current climate and climate change scenarios resulting from moderate and very high greenhouse gas emissions; (2) how maximum landscape yield, spatial allocation of crops, and bioenergy hotspots (areas with highest potential yield) varied among climate scenarios; and (3) how bioenergy hotspots overlapped with current crop production or lands with high development pressure. Under both climate change scenarios, mean annual yield of perennial grasses decreased (-4% to -39%), but yield of hybrid poplar increased (+8% to +20%) which suggests that a switch to woody crops would maximize bioenergy crop production. In total, maximum landscape yield increased by up to 90 000 Mg/yr (6%) in the 21st century due to increased poplar production. Bioenergy hotspots (> 18 Mg x ha(-1) x yr(-1)) consistently overlapped with high suburban/exurban development likelihood and existing row crop production. If bioenergy production is constrained to marginal (non-crop) lands

  13. Genomic prediction in families of perennial ryegrass based on genotyping-by-sequencing

    DEFF Research Database (Denmark)

    Ashraf, Bilal

    In this thesis we investigate the potential for genomic prediction in perennial ryegrass using genotyping-by-sequencing (GBS) data. Association method based on family-based breeding systems was developed, genomic heritabilities, genomic prediction accurancies and effects of some key factors wer...... prediction. Overall, GBS allows for genomic prediction in breeding families of perennial ryegrass and holds good potential to expedite genetic gain and encourage the application of genomic prediction...

  14. High-Throughput SNP Discovery And Genetic Mapping In Perennial Ryegrass

    DEFF Research Database (Denmark)

    Asp, Torben; Studer, Bruno; Lübberstedt, Thomas

    Gene-associated single nucleotide polymorphisms (SNPs) are of major interest for genome analysis and breeding applications in the key grassland species perennial ryegrass. High-throughput 454 Titanium transcriptome sequencing was performed on two genotypes, which previously have been used...... in the VrnA mapping population. Here we report on large-scale SNP discovery, and the construction of a genetic map enabling QTL fine mapping, map-based cloning, and comparative genomics in perennial ryegrass....

  15. Numerical simulation of cropping

    DEFF Research Database (Denmark)

    Tvergaard, Viggo; Hutchinson, John W.

    2014-01-01

    Cropping is a cutting process whereby opposing aligned blades create a shearing failure by exerting opposing forces normal to the surfaces of a metal sheet or plate. Building on recent efforts to quantify cropping, this paper formulates a plane strain elastic-plastic model of a plate subject to s...

  16. Winter cover crops decrease weediness in organic cropping systems

    OpenAIRE

    Madsen, Helena; Talgre, Liina; Eremeev, Vyacheslav; Alaru, Maarika; Maeorg, Erkki; Luik, Anne

    2017-01-01

    By inserting cover crops into organic cropping systems, the number and biomass of weeds decreased. Winter cover crops clearly have a suppressive effect on weeds by providing competition for light, water and space.

  17. Pendulous Crop in Broilers

    Directory of Open Access Journals (Sweden)

    PD Ebling

    2015-09-01

    Full Text Available ABSTRACTPendulous crop is a physiological disorder, which etiology is still unknown and it is characterized by abnormal dilation of the crop of poultry. This article aims at reporting a case of high incidence of pendulous crop in male and female broilers Cobb 500, as well as to discuss its possible causes and consequences. In an experiment with broilers performed at the experimental facilities of Laboratório de Ensino Zootécnico of UFRGS, a high incidence (9.5% of pendulous crop was observed. Genetic predisposition is the most frequently documented and accepted cause of that condition. Despite presenting the same live weight as normal broilers, birds with pendulous crop had lower carcass weight due to dehydration and malnourishment, and should be culled after diagnosis. Therefore, further studies on the origin and control of this physiological disorder are warranted.

  18. Serendipitous backyard hybridization and the origin of crops.

    Science.gov (United States)

    Hughes, Colin E; Govindarajulu, Rajanikanth; Robertson, Ashley; Filer, Denis L; Harris, Stephen A; Bailey, C Donovan

    2007-09-04

    Backyard gardens, dump heaps, and kitchen middens are thought to have provided important venues for early crop domestication via generation of hybrids between otherwise isolated plant species. However, this process has rarely been demonstrated empirically. For the majority of polyploid crops, it remains uncertain to what extent hybridization and polyploidization preceded domestication or were precipitated by human activities. Using archaeological, ethnobotanical, geographical, and genetic data, we investigate the extent and significance of predomestication cultivation, backyard sympatry, and spontaneous hybridization for the Mimosoid legume tree Leucaena, which is used as a food crop throughout south-central Mexico. We show that predomestication cultivation was widespread, involved numerous independent transitions from the wild to cultivation, and resulted in extensive artificial sympatry of 2-6 species locally and 13 species in total. Using chloroplast and rapidly evolving nuclear-encoded DNA sequences, we demonstrate that hybridization in Leucaena has been extensive and complex, spawning a diverse set of novel hybrids as a result of juxtaposition of species in cultivation. The scale and complexity of hybridization in Leucaena is significantly greater than that documented for any other Mexican plant domesticates so far. However, there are striking parallels between Leucaena and the other major Mexican perennial domesticates Agave and Opuntia, which show very similar domestication via backyard hybridization pathways. Our results suggest that backyard hybridization has played a central role in Mesoamerican crop domestication and demonstrate that the simple step of bringing species together in cultivation can provide a potent trigger for domestication.

  19. The RHEA-project robot for tree crops pesticide application

    Directory of Open Access Journals (Sweden)

    Marco Vieri

    2013-09-01

    Full Text Available The sustainable use of pesticide and the need of a renewed integrated system of agricultural knowledge and management, focus the designing of the EU FP7 RHEA Project. The objectives are the design, development, and testing of a new automatic generation of robotic systems to perform field operations for the sustainable crop management. The project affects three case study: chemical, physical, mechanical and thermal effective weed management in maize and wheat cultivations and chemical pesticide management in woody crops. To achieve the goals, a fleet of small and heterogeneous robots, ground and aerial, equipped with advanced sensors, innovative end actuators and decision control algorithms were realized. Present work is related to the third case study considered i.e. the spraying in woody crops specifically in olive trees. The final decision on woody perennial crops treatment device system, was oriented toward a complete double side air blast sprayer with eight separate spraying modules on four vertical bands of the canopy. Rhea air blast sprayer introduces some important innovations in the studies concerning the pesticide variable rate treatment, i.e. the management possibility of air flow in site specific way and in real time in function of the target.

  20. Seed vs. microsite limitation for seedling emergence in the perennial grass Stipa tenacissima L. (Poaceae)

    Science.gov (United States)

    García-Fayos, Patricio; Gasque, María

    2006-09-01

    This paper examines the relative influence of seed and microsite availability in the seedling emergence of Stipa tenacissima, a perennial grass inhabiting semi-arid Mediterranean steppes. A correlative approximation was used to establish 21 (10 × 10 m) plots along a climatic gradient in the Northern limit of the geographic distribution in East Spain. Seed production, seed removal by ants, ant nest density, and the relative cover of S. tenacissima, other perennial plants and bare ground, as explanatory variables, were measured in each plot. Multiple linear regression with forward stepwise selection procedure was used to analyze the relationships between seedling emergence and the explanatory variables. There was large variation between and within plots of all the studied variables, but cover of perennial plants was the only explanatory variable included in the regression model when all the plots were used for the analysis. We suggest that this result was the consequence that high annual precipitation on the Northernmost plots had on the cover of perennial plants and it is consistent with the experimental evidence that shadowing by perennial plants negatively affects germination and performance of the S. tenacissima seedlings. Once the Northernmost plots were removed from the model of regression then seed production, seed removal by ants and ant nest density significantly affected seedling emergence. We concluded that microsite quality, defined in relation to the shadowing capacity of perennial species, was more influential than seed and microsite availability at the Northern limit of the geographic distribution of S. tenacissima.

  1. Perennial non-infectious rhinitis--an independent risk factor for sleep disturbances in Asthma.

    Science.gov (United States)

    Hellgren, Johan; Omenaas, Ernst; Gíslason, Thórarinn; Jögi, Rain; Franklin, Karl A; Lindberg, Eva; Janson, Christer; Torén, Kjell

    2007-05-01

    To evaluate if perennial non-infectious rhinitis is associated with sleep disturbances in asthma. This is a questionnaire based study in a random population sample from Denmark, Estonia, Iceland, Norway and Sweden aged 30-54yr. A total of 1127 individuals reporting asthma from an original random population sample of 16,191 were analysed regarding their quality of sleep in relation to perennial non-infectious rhinitis. Perennial non-infectious rhinitis was defined as having nasal symptoms such as nasal blockage and secretion in the absence of common cold, always. Asthma was defined as both ever having had asthma and having physician diagnosed asthma. Odds ratios (OR) for difficulties inducing sleep, difficulties maintaining sleep, early morning awakenings and daytime sleepiness were calculated in a multiple logistic regression controlling for other risk factors for sleep disturbances such as snoring, wheeze, obesity and smoking. The response rate was 74%. A total of 189 (17%) of the subjects with asthma reported perennial non-infectious rhinitis. Perennial non-infectious rhinitis was associated with an increased OR for difficulties maintaining sleep (1.6 (95% confidence interval (CI) 1.1-2.3)), early morning awakenings (1.5 (95% CI 1.1-2.2)) and daytime sleepiness (1.8 (95% CI 1.2-2.9)). The result show that perennial non-infectious rhinitis is an independant risk factor for sleep disturbances in asthma.

  2. Viability of Cryptosporidium parvum during ensilage of perennial ryegrass.

    Science.gov (United States)

    Merry, R J; Mawdsley, J L; Brooks, A E; Davies, D R

    1997-01-01

    The survival of Cryptosporidium parvum during ensilage of perennial ryegrass was examined in laboratory silos with herbage prepared in one of three different ways; either untreated, inoculated with a strain of Lactobacillus plantarum or by direct acidification with formic acid. The pH values of all silages initially fell below 4.5, but only formic acid-treated silage remained stable at less than pH 4 after 106 d, with the pH of the untreated and inoculant-treated silages rising to above 6. The formic acid-treated silage had a high lactic acid concentration (109 g kg-1 dry matter (DM)) and low concentrations of propionic and butyric acids after 106 d. However, the untreated and inoculant-treated silages showed an inverse relationship, with low lactic acid concentrations and high concentrations of acetic, propionic and butyric acids. These silages also contained ammonia-N concentrations in excess of 9 g kg-1 DM. In terms of the viability of Cryptosporidium parvum oocysts very few differences were seen after 14 d of ensilage with ca 50% remaining viable, irrespective of treatment and total numbers had declined from the initial level of 5.9 x 10(4) to 1 x 10(4) g(-1) fresh matter. Total oocyst numbers remained approximately the same until the end of the ensiling period, with the percentage of viable oocysts declining to 46, 41 and 32% respectively for formic acid, inoculant and untreated silages. The results are discussed in terms of changes occurring during the silage fermentation, in particular the products which may influence the survival of Cryptosporidium and implications for agricultural practice and the health of silage fed livestock.

  3. Culture in psychology: Perennial problems and the contemporary methodological crisis.

    Directory of Open Access Journals (Sweden)

    Mironenko, I.A.

    2015-07-01

    Full Text Available This article begins by discussing the origins of the methodological crisis in psychology. In the literature the idea of a permanent methodological crisis in psychology, lasting since the 1890s, dominates. We contest this view and argue that the contemporary methodological problems in psychology should be considered within the context of the novel and larger crisis challenging all socio-humanitarian knowledge in the face of the transformations in social reality in recent decades. The nature of these transformations and their implications for the theory and methodology of the socio-humanitarian sciences are analyzed by drawing on the sociological literature, which is more sensitive to changes in social life than is psychology. Prominent sociologists argue that the “old” theories and interpretations of the “social” are no longer relevant in the new, highly complex, and globally unstable reality; this new reality has largely transformed the dimensions of human beings’ existence. Meanwhile psychology still tends to comprehend the universal nature of the human. This position undermines the relevance of both psychology’s theoretical models and the practical implications derived from these methodological assumptions. We argue for revision of the perennial psychological problem of the biology-culture interaction in human nature. To resolve the contemporary methodological crisis in psychology, a shift is needed from theories of universal and immutable human nature to the idea of the human as an infinitely changing creature. Because culture is, primarily, the ability to change, wherein the speed and extent of changes are unique for humans, distinguishing them from other living beings.

  4. Effects of stored feed cropping systems and farm size on the profitability of Maine organic dairy farm simulations.

    Science.gov (United States)

    Hoshide, A K; Halloran, J M; Kersbergen, R J; Griffin, T S; DeFauw, S L; LaGasse, B J; Jain, S

    2011-11-01

    United States organic dairy production has increased to meet the growing demand for organic milk. Despite higher prices received for milk, organic dairy farmers have come under increasing financial stress due to increases in concentrated feed prices over the past few years, which can make up one-third of variable costs. Market demand for milk has also leveled in the last year, resulting in some downward pressure on prices paid to dairy farmers. Organic dairy farmers in the Northeast United States have experimented with growing different forage and grain crops to maximize on-farm production of protein and energy to improve profitability. Three representative organic feed systems were simulated using the integrated farm system model for farms with 30, 120, and 220 milk cows. Increasing intensity of equipment use was represented by organic dairy farms growing only perennial sod (low) to those with corn-based forage systems, which purchase supplemental grain (medium) or which produce and feed soybeans (high). The relative profitability of these 3 organic feed systems was strongly dependent on dairy farm size. From results, we suggest smaller organic dairy farms can be more profitable with perennial sod-based rather than corn-based forage systems due to lower fixed costs from using only equipment associated with perennial forage harvest and storage. The largest farm size was more profitable using a corn-based system due to greater economies of scale for growing soybeans, corn grain, winter cereals, and corn silages. At an intermediate farm size of 120 cows, corn-based forage systems were more profitable if perennial sod was not harvested at optimum quality, corn was grown on better soils, or if milk yield was 10% higher. Delayed harvest decreased the protein and energy content of perennial sod crops, requiring more purchased grain to balance the ration and resulting in lower profits. Corn-based systems were less affected by lower perennial forage quality, as corn silage

  5. Assessing the Impacts of Land Use Change from Cotton to Perennial Bioenergy Grasses on Hydrological Fluxes and Water Quality in a Semi-Arid Agricultural Watershed Using the APEX Model

    Science.gov (United States)

    Chen, Y.; Ale, S.; Rajan, N.

    2015-12-01

    The semi-arid Texas High Plains (THP) region, where cotton (Gossypium hirsutum L.) is grown in vast acreage, has the potential to grow perennial bioenergy grasses. A change in land use from cotton cropping systems to perennial grasses such as Alamo switchgrass (Panicum virgatum L.) and Miscanthus giganteus (Miscanthus sinensis Anderss. [Poaceae]) can significantly affect regional hydrologic cycle and water quality. Assessing the impacts of this potential land use change on hydrology and water quality enables the environmental assessment of feasibility to grow perennial grasses in this region to meet the U.S. national bioenergy target of 2022. The Agricultural Policy/Environmental eXtender (APEX) model was used in this study to assess the impacts of replacing cotton with switchgrass and Miscanthus on water and nitrogen balances in the upstream subwatershed of the Double Mountain Fork Brazos watershed in the THP, which contains 52% cotton land use. The APEX model was initially calibrated against observed streamflow and crop yield data. Since observed data on nitrogen loads in streamflow was not available for this subwatershed, we calibrated the APEX model against the SWAT-simulated nitrogen loads at the outlet of this subwatershed, which were obtained in a parallel study. The calibrated APEX model was used to simulate the impacts of land use change from cotton to Miscanthus and switchgrass on surface and subsurface water and nitrogen balances. Preliminary results revealed that the average (1994-2009) annual surface runoff decreased by 84% and 66% under the irrigated and dryland switchgrass scenarios compared to the baseline scenarios. Average annual percolation increased by 106% and 57% under the irrigated and dryland switchgrass scenarios relative to the baseline scenarios. Preliminary results also indicated Miscanthus and switchgrass appeared to be superior to cotton in terms of better water conservation and water quality, and minimum crop management requirements.

  6. Applied crop protection 2016

    DEFF Research Database (Denmark)

    Jørgensen, Lise Nistrup; Nielsen, Bent Jørgen; Jensen, Peter Kryger

    This publication contains results from crop protection trials which were carried out at the Department of Agroecology within the area of agricultural crops. Most of the results come from field trials, but results from greenhouse and semi-field trials are also included. The report contains results...... that throw light upon: • Effects of new pesticides • Results of different control strategies, including how to control specific pests, as part of an integrated control strategy involving both cultivars and control thresholds • Results with pesticide resistance • Trial results from different cropping systems...

  7. Breeding of catch crops - a way to reduce nitrate leaching from arable land

    Energy Technology Data Exchange (ETDEWEB)

    Rydberg, I. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Plant Biology

    1998-12-01

    Nitrogen in the form of nitrate is soluble in water and nitrate can therefore leach into water systems. Several changes of agricultural practice the last 50 years have promoted nitrogen leaching. Crops with long vegetation periods give less leaching problems than crops with short growing seasons. In Sweden, areas in the South West have the most severe leaching. A catch crop can be defined as a crop grown between two main commercial crops, with the specific mission to reduce leaching of nutrients. The motivation for this plant breeding project was the positive effect of decreased leaching obtained when undersown catch crops were used. A research programme was initiated with the aim of developing a theoretical ideotype for an optimal catch crop and of identifying species for use in applied agriculture. The characteristics of the ideotype include the interaction of the catch crop with the main crop (low influence on the yield of the main crop), its function as a catch crop for nitrogen (high influence on nitrate leaching) and presumed consequences in the cropping system (low influence on crop rotation). 134 species (1083 different accessions) of both agrarian, non agrarian, domesticated and non domesticated origin were included in a screening. The work included model experiments in the greenhouse for responses to reduced light and uptake of nitrogen using {sup 15}N fertilizer as well as field trials, testing growth of catch crop, grain yield of the main crop, and reduction of nitrate in the soil. The ideotype was very useful in the screening, and promising species were identified. A number of biennial and perennial species proved to comply with the ideotype and possess prerequisites beneficial for catch crop purposes. One of them, chicory, showed that a depletion of nitrate during periods with risk of high nitrate leaching, could be combined with later access to this nutrient by the succeeding crop. Legumes had problems in combining all traits presented in the

  8. The soils of the lower eastern slopes of the Cameroon mountain and their suitability for various perennial crops

    NARCIS (Netherlands)

    Hasselo, H.N.

    1961-01-01

    On the eastern slopes of the Cameroon Mountains soils occurring below the 100- metre contour were surveyed on a scale 1:25,000. Most soils are young marine clay soils used for growing bananas, oilpalms, cocoa, rubber and tea. At some places there are lava streams from the mountains.

    A more

  9. Increased prevalence of perennial allergic rhinitis in patients with obstructive sleep apnea.

    Science.gov (United States)

    Canova, C R; Downs, S H; Knoblauch, A; Andersson, M; Tamm, M; Leuppi, J D

    2004-01-01

    Impaired nasal breathing is a risk factor for obstructive sleep apnea syndrome (OSAS). The aim of this study was to determine whether atopy to perennial allergens and existence of perennial allergic rhinitis was a risk factor for OSAS. In a case-control study, we compared the proportions of OSAS patients with atopy to perennial allergens and perennial allergic rhinitis to the proportions in patients with chronic obstructive pulmonary disease (COPD). Seventy-two OSAS patients (mean age 60.7 years; 79.4% male) and 44 COPD patients (mean age 63.6 years; 88.6% male) were selected from a hospital outpatients' clinic in Switzerland. All patients completed a respiratory symptom questionnaire, performed spirometry and had a skin prick test for atopy. OSAS patients were significantly heavier than COPD patients (BMI 32.4 +/- (SD) 6.6 vs. 29.2 +/- 6.6 kg/m2, p = 0.04) and had a better lung function than COPD patients (FEV1% predicted 91.3 +/- 19.2 vs. 51.6 +/- 18.9%, p allergic rhinitis (having nose problems [nasal obstruction and/or runny nose and/or sneezing] all year and being atopic to at least one perennial allergen) was reported in 11% of OSAS patients but in only 2.3% of COPD patients (p = 0.15). We conclude that subjects with OSAS may have an increased risk of being allergic to perennial allergens and suffer from perennial rhinitis. Awareness of this risk may have important consideration in the clinical situation. Copyright 2004 S. Karger AG, Basel

  10. The use of linear mixed models for analysis of repeated measurements applied to water-soluble carbohydrates in perennial ryegrass for seed production

    DEFF Research Database (Denmark)

    Gislum, René; Boelt, Birte; Zhang, Xia

    2009-01-01

    Repeated measurements of a response variable in crops or plants receiving different treatments are widely used in agricultural science. In this paper we analyse repeated measurements of the concentration of water-soluble carbohydrates in stem and ear of perennial ryegrass (Lolium perenne L....... The estimates of the water-soluble carbohydrates concentrations within the stem and ear datasets were similar for all three covariance structures, while the smallest standard errors were obtained using the compound symmetry covariance structure. As it was the goal to do parsimonious modelling more weight...... was given to the Bayesian information criteria than to the Akaike information criteria. Accordingly, the compound symmetry structure was chosen for the stem data and the unstructured structure was found to be the best structure for the ear data. A model check of the residuals showed...

  11. Viruses in the desert: a metagenomic survey of viral communities in four perennial ponds of the Mauritanian Sahara.

    Science.gov (United States)

    Fancello, Laura; Trape, Sébatien; Robert, Catherine; Boyer, Mickaël; Popgeorgiev, Nikolay; Raoult, Didier; Desnues, Christelle

    2013-02-01

    Here, we present the first metagenomic study of viral communities from four perennial ponds (gueltas) located in the central Sahara (Mauritania). Three of the four gueltas (Ilij, Molomhar and Hamdoun) are located at the source of three different wadis belonging to the same hydrologic basin, whereas the fourth (El Berbera) belongs to a different basin. Overall, sequences belonging to tailed bacteriophages were the most abundant in all four metagenomes although electron microscopy and sequencing confirmed the presence of other viral groups, such as large DNA viruses. We observed a decrease in the local viral biodiversity in El Berbera, a guelta with sustained human activities, compared with the pristine Ilij and Molomhar, and sequences related to viruses infecting crop pests were also detected as a probable consequence of the agricultural use of the soil. However, the structure of the El Berbera viral community shared the common global characteristics of the pristine gueltas, that is, it was dominated by Myoviridae and, more particularly, by virulent phages infecting photosynthetic cyanobacteria, such as Prochlorococcus and Synechococcus spp. In contrast, the Hamdoun viral community was characterized by a larger proportion of phages with the potential for a temperate lifestyle and by dominant species related to phages infecting heterotrophic bacteria commonly found in terrestrial environments. We hypothesized that the differences observed in the structural and functional composition of the Hamdoun viral community resulted from the critically low water level experienced by the guelta.

  12. Constraints to obtaining consistent annual yields in perennials. II: Environment and fruit load affect induction of flowering.

    Science.gov (United States)

    Samach, Alon; Smith, Harley M

    2013-06-01

    In many commercial fruit crop species, high fruit load inhibits vegetative growth and floral induction. As a result, trees that had a high fruit load will bear few flowers and fruit the following year, along with abundant vegetative growth. We previously discussed how high fruit load interferes with concurrent shoot growth. Here we focus on how high fruit load impacts the process of flowering. Ascertaining the precise time at which specific buds begin the floral transition in each species is challenging. The use of indirect approaches to determine time of floral induction or evocation may lead to questionable conclusions. Annual and perennial plants appear to use conserved proteins for flowering induction and initiation. The accumulation or reduction of transcripts encoding proteins similar to Arabidopsis (annual) FLOWERING LOCUS T (FT) and TERMINAL FLOWER1 (TFL1), respectively, correlates well with flower induction in several diverse species. The recent use of such markers provides a means to formulate an accurate timeframe for floral induction in different species and holds promise in providing new insight into this important developmental event. A role for hormones in modulating the inhibitory effect of fruit load on floral induction is also discussed. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  13. EARLY BUD-BREAK1 (EBB1) defines a conserved mechanism for control of bud-break in woody perennials.

    Science.gov (United States)

    Busov, Victor; Carneros, Elena; Yakovlev, Igor

    2016-01-01

    Bud-break is an environmentally and economically important trait in trees, shrubs and vines from temperate latitudes. Poor synchronization of bud-break timing with local climates can lead to frost injuries, susceptibility to pests and pathogens and poor crop yields in fruit trees and vines. The rapid climate changes outpace the adaptive capacities of plants to respond through natural selection. This is particularly true for trees which have long generation cycle and thus the adaptive changes are significantly delayed. Therefore, to devise appropriate breeding and conservation strategies, it is imperative to understand the molecular underpinnings that govern dormancy mechanisms. We have recently identified and characterized the poplar EARLY BUD-BREAK 1 (EBB1) gene. EBB1 is a positive regulator of bud-break and encodes a transcription factor from the AP2/ERF family. Here, using comparative and functional genomics approaches we show that EBB1 function in regulation of bud-break is likely conserved across wide range of woody perennial species with importance to forestry and agriculture.

  14. Cereal Crops Research Unit

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the Cereal Crops Research Unit is to 1) conduct basic research to identify and understand the biological processes affecting the growth, development...

  15. Dinosaur demise in light of their alleged perennial polar residency

    Science.gov (United States)

    Lewy, Zeev

    2017-10-01

    The end-Cretaceous biological crisis is represented by the demise of the non-avian dinosaurs. However, most crucial biologically was the elimination of the photosynthesizing marine phyto- and zooplankton forming the base of the marine food chain. Their abrupt demise attests to sunlight screening darkening the atmosphere for a few years. Alvarez et al. (Science 208:1095-1108, 1980. doi: 10.1126/science.208.44) noticed in deep marine end-Cretaceous sediments an anomalous rise in the chemical element iridium (Ir), which is rare on planet Earth and thus suggests an extraterrestrial origin through an impact of a large asteroid. This impact would have ejected enormous quantities of particles and aerosols, shading the solar illumination as attested to by the elimination of the marine photosynthesizing plankton. Such a dark period must have affected life on land. The apparent cold-blooded non-avian dinosaurs, which were used to living in open terrains to absorb the solar illumination, became inactive during the dark period and were incapable of withstanding predators. This was in contrast to cold-blooded crocodilians, turtles and lizards that could hide in refuge sites on land and in the water. Dinosaur relics discovered in Cretaceous Polar Regions were attributed to perennial residents, surviving the nearly half-year-long dark winter despite their ability to leave. The polar concentrations of disarticulated dinosaur bones were suggested as having resulted from a catastrophic burial of a population by floods. However, this should have fossilized complete skeletons. Alternatively, herds of dinosaurs living in high latitudes might have been sexually driven to spend the half year of continuously illuminated polar summer for mating rather than for nourishment, in which the lower latitudes provided as well. The aggressive mating competitions would have left victims among the rivals and of young ones incidentally trampled over, all being consumed and their skeletons

  16. Dinosaur demise in light of their alleged perennial polar residency

    Science.gov (United States)

    Lewy, Zeev

    2016-12-01

    The end-Cretaceous biological crisis is represented by the demise of the non-avian dinosaurs. However, most crucial biologically was the elimination of the photosynthesizing marine phyto- and zooplankton forming the base of the marine food chain. Their abrupt demise attests to sunlight screening darkening the atmosphere for a few years. Alvarez et al. (Science 208:1095-1108, 1980. doi: 10.1126/science.208.44) noticed in deep marine end-Cretaceous sediments an anomalous rise in the chemical element iridium (Ir), which is rare on planet Earth and thus suggests an extraterrestrial origin through an impact of a large asteroid. This impact would have ejected enormous quantities of particles and aerosols, shading the solar illumination as attested to by the elimination of the marine photosynthesizing plankton. Such a dark period must have affected life on land. The apparent cold-blooded non-avian dinosaurs, which were used to living in open terrains to absorb the solar illumination, became inactive during the dark period and were incapable of withstanding predators. This was in contrast to cold-blooded crocodilians, turtles and lizards that could hide in refuge sites on land and in the water. Dinosaur relics discovered in Cretaceous Polar Regions were attributed to perennial residents, surviving the nearly half-year-long dark winter despite their ability to leave. The polar concentrations of disarticulated dinosaur bones were suggested as having resulted from a catastrophic burial of a population by floods. However, this should have fossilized complete skeletons. Alternatively, herds of dinosaurs living in high latitudes might have been sexually driven to spend the half year of continuously illuminated polar summer for mating rather than for nourishment, in which the lower latitudes provided as well. The aggressive mating competitions would have left victims among the rivals and of young ones incidentally trampled over, all being consumed and their skeletons

  17. Radioactivity in food crops

    Energy Technology Data Exchange (ETDEWEB)

    Drury, J.S.; Baldauf, M.F.; Daniel, E.W.; Fore, C.S.; Uziel, M.S.

    1983-05-01

    Published levels of radioactivity in food crops from 21 countries and 4 island chains of Oceania are listed. The tabulation includes more than 3000 examples of 100 different crops. Data are arranged alphabetically by food crop and geographical origin. The sampling date, nuclide measured, mean radioactivity, range of radioactivities, sample basis, number of samples analyzed, and bibliographic citation are given for each entry, when available. Analyses were reported most frequently for /sup 137/Cs, /sup 40/K, /sup 90/Sr, /sup 226/Ra, /sup 228/Ra, plutonium, uranium, total alpha, and total beta, but a few authors also reported data for /sup 241/Am, /sup 7/Be, /sup 60/Co, /sup 55/Fe, /sup 3/H, /sup 131/I, /sup 54/Mn, /sup 95/Nb, /sup 210/Pb, /sup 210/Po, /sup 106/Ru, /sup 125/Sb, /sup 228/Th, /sup 232/Th, and /sup 95/Zr. Based on the reported data it appears that radioactivity from alpha emitters in food crops is usually low, on the order of 0.1 Bq.g/sup -1/ (wet weight) or less. Reported values of beta radiation in a given crop generally appear to be several orders of magnitude greater than those of alpha emitters. The most striking aspect of the data is the great range of radioactivity reported for a given nuclide in similar food crops with different geographical origins.

  18. Impacts of Organic Zero Tillage Systems on Crops, Weeds, and Soil Quality

    Directory of Open Access Journals (Sweden)

    Patrick M. Carr

    2013-07-01

    Full Text Available Organic farming has been identified as promoting soil quality even though tillage is used for weed suppression. Adopting zero tillage and other conservation tillage practices can enhance soil quality in cropping systems where synthetic agri-chemicals are relied on for crop nutrition and weed control. Attempts have been made to eliminate tillage completely when growing several field crops organically. Vegetative mulch produced by killed cover crops in organic zero tillage systems can suppress annual weeds, but large amounts are needed for adequate early season weed control. Established perennial weeds are not controlled by cover crop mulch. Integrated weed management strategies that include other cultural as well as biological and mechanical controls have potential and need to be incorporated into organic zero tillage research efforts. Market crop performance in organic zero tillage systems has been mixed because of weed, nutrient cycling, and other problems that still must be solved. Soil quality benefits have been demonstrated in comparisons between organic conservation tillage and inversion tillage systems, but studies that include zero tillage treatments are lacking. Research is needed which identifies agronomic strategies for optimum market crop performance, acceptable levels of weed suppression, and soil quality benefits following adoption of organic zero tillage.

  19. Barriers to and drivers of the adpotion of energy crops by Swedish farmers: An empirical approach

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, Anna C.; Ostwald, Madelene; Asplund, Therese; Wibeck, Victoria (Linkoeping Univ., Linkoeping (Sweden). The Tema Inst., Centre for Climate Science and Policy Research)

    2011-06-15

    Since the Swedish government and the EU intend to encourage farmers to expand energy crop production, knowledge of the factors motivating adoption decisions is vital to policy success. Earlier studies have demonstrated that important barriers to farmer adoption of energy crops include converting from annual to perennial crops and from traditional crops or production systems to new ones. Economic motivations for changing production systems are strong, but factors such as values (e.g., aesthetics), knowledge (e.g., habits and knowledge of production methods), and legal conditions (e.g., cultivation licenses) are crucial for the change to energy crops. This paper helps fill gaps in the literature regarding why farmers decide to keep or change a production system. Based on a series of focus group interviews with Swedish farmers, the paper explores how farmers frame crop change decisions and what factors they consider most important. The main drivers of and barriers to growing energy crops, according to interviewees, are grouped and discussed in relation to four broad groups of motivational factors identified in the literature, i.e., values, legal conditions, knowledge, and economic factors. The paper ends by discussing whether some barriers could be overcome by policy changes at the national and European levels

  20. Breeding better cultivars, faster: applications of new technologies for the rapid deployment of superior horticultural tree crops

    Science.gov (United States)

    van Nocker, Steve; Gardiner, Susan E

    2014-01-01

    Woody perennial plants, including trees that produce fruits and nuts of horticultural value, typically have long breeding cycles, and development and introduction of improved cultivars by plant breeders may require many breeding cycles and dozens of years. However, recent advances in biotechnologies and genomics have the potential to accelerate cultivar development greatly in all crops. This mini-review summarizes approaches to reduce the number and the duration of breeding cycles for horticultural tree crops, and outlines the challenges that remain to implement these into efficient breeding pipelines. PMID:26504538

  1. Increasing Cultivar Diversity of Processing Tomato under Large Scale Organic Production in California

    OpenAIRE

    Barrios Masias, Felipe; Jackson, Louise

    2008-01-01

    At an organic farm in California, higher plant diversity was hypothesized to enhance ecosystem functions and services. Plant diversity was manipulated temporally and spatially: mustard cover crop vs. no cover crop (fallow) in winter, and mixtures with one (farmer’s best choice), three, or five processing tomato cultivars in summer. Soil N, soil microbial biomass, crop nutrient uptake, canopy light interception, disease, GHG emissions and biomass were measured. Results show that the mustard co...

  2. Modelling the carbon and nitrogen balances of direct land use changes from energy crops in Denmark

    DEFF Research Database (Denmark)

    Hamelin, Lorie; Jørgensen, Uffe; Petersen, Bjørn Molt

    2012-01-01

    and perennials), two soil types (sandy loam and sand), two climate types (wet and dry), three initial soil carbon level (high, average, low), two time horizons for soil carbon changes (20 and 100 years), two residues management practices (removal and incorporation into soil) as well as three soil carbon turnover......- and micronutrients are presented. The inventory results highlight Miscanthus as a promising energy crop, indicating it presents the lowest emissions of nitrogen compounds, the highest amount of carbon dioxide sequestrated from the atmosphere, a relatively high carbon turnover efficiency and allows to increase soil...... organic carbon. Results also show that the magnitude of these benefits depends on the harvest season, soil types and climatic conditions. Inventory results further highlight winter wheat as the only annual crop where straw removal for bioenergy may be sustainable, being the only annual crop not involving...

  3. Invasion Age and Invader Removal Alter Species Cover and Composition at the Suisun Tidal Marsh, California, USA

    Directory of Open Access Journals (Sweden)

    Sarah Estrella

    2011-05-01

    Full Text Available Wetland ecosystems are vulnerable to plant species invasions, which can greatly alter species composition and ecosystem functioning. The response of these communities to restoration can vary following invader removal, but few studies have evaluated how recent and long-term invasions can affect the plant community’s restoration potential. Perennial pepperweed (Lepidium latifolium has invaded thousands of hectares of marshland in the San Francisco Estuary, California, United States of America, while the effects of invasion and removal of this weed remain poorly studied. In this study, perennial pepperweed was removed along a gradient of invasion age in brackish tidal marshes of Suisun Marsh, within the Estuary. In removal plots, resident plant cover significantly increased during the 2-year study period, particularly in the densest and oldest parts of the perennial pepperweed colonies, while species richness did not change significantly. In bare areas created by removal of perennial pepperweed, recolonization was dominated by three-square bulrush (Schoenoplectus americanus. Ultimately, removal of invasive perennial pepperweed led to reinvasion of the resident plant community within two years. This study illustrates that it is important to consider invasion age, along with exotic species removal, when developing a restoration strategy in wetland ecosystems.

  4. A comparative study of AMF diversity in annual and perennial plant species from semiarid gypsum soils.

    Science.gov (United States)

    Alguacil, M. M.; Torrecillas, E.; Roldán, A.; Díaz, G.; Torres, P.

    2012-04-01

    The arbuscular mycorrhizal fungi (AMF) communities composition regulate plant interactions and determine the structure of plant communities. In this study we analysed the diversity of AMF in the roots of two perennial gypsophyte plant species, Herniaria fruticosa and Senecio auricula, and an annual herbaceous species, Bromus rubens, growing in a gypsum soil from a semiarid area. The objective was to determine whether perennial and annual host plants support different AMF communities in their roots and whether there are AMF species that might be indicators of specific functional plant roles in these ecosystems. The roots were analysed by nested PCR, cloning, sequencing of the ribosomal DNA small subunit region and phylogenetic analysis. Twenty AMF sequence types, belonging to the Glomus group A, Glomus group B, Diversisporaceae, Acaulosporaceae, Archaeosporaceae and Paraglomeraceae, were identified. Both gypsophyte perennial species had differing compositions of the AMF community and higher diversity when compared with the annual species, showing preferential selection by specific AMF sequences types. B. rubens did not show host specificity, sharing the full composition of its AMF community with both perennial plant species. Seasonal variations in the competitiveness of AM fungi could explain the observed differences in AMF community composition, but this is still a working hypothesis that requires the analysis of further data obtained from a higher number of both annual and perennial plant species in order to be fully tested.

  5. Soil nitrate testing supports nitrogen management in irrigated annual crops

    Directory of Open Access Journals (Sweden)

    Patricia A. Lazicki

    2016-12-01

    Full Text Available Soil nitrate (NO3− tests are an integral part of nutrient management in annual crops. They help growers make field-specific nitrogen (N fertilization decisions, use N more efficiently and, if necessary, comply with California's Irrigated Lands Regulatory Program, which requires an N management plan and an estimate of soil NO3− from most growers. As NO3− is easily leached into deeper soil layers and groundwater by rain and excess irrigation water, precipitation and irrigation schedules need to be taken into account when sampling soil and interpreting test results. We reviewed current knowledge on best practices for taking and using soil NO3− tests in California irrigated annual crops, including how sampling for soil NO3− differs from sampling for other nutrients, how tests performed at different times of the year are interpreted and some of the special challenges associated with NO3− testing in organic systems.

  6. Biotechnology: herbicide-resistant crops

    Science.gov (United States)

    Transgenic, herbicide-resistant (HR) crops are planted on about 80% of the land covered by transgenic crops. More than 90% of HR crios are glyphosate-resistant (GR) crops, the others being resistant to glufosinate. The wide-scale adoption of HR crops, largely for economic reasons, has been the mos...

  7. Comparing net ecosystem carbon dioxide exchange at adjacent commercial bioenergy and conventional cropping systems in Lincolnshire, United Kingdom

    Science.gov (United States)

    Morrison, Ross; Brooks, Milo; Evans, Jonathan; Finch, Jon; Rowe, Rebecca; Rylett, Daniel; McNamara, Niall

    2016-04-01

    The conversion of agricultural land to bioenergy plantations represents one option in the national and global effort to reduce greenhouse gas emissions whilst meeting future energy demand. Despite an increase in the area of (e.g. perennial) bioenergy crops in the United Kingdom and elsewhere, the biophysical and biogeochemical impacts of large scale conversion of arable and other land cover types to bioenergy cropping systems remain poorly characterised and uncertain. Here, the results of four years of eddy covariance (EC) flux measurements of net ecosystem CO2 exchange (NEE) obtained at a commercial farm in Lincolnshire, United Kingdom (UK) are reported. CO2 flux measurements are presented and compared for arable crops (winter wheat, oilseed rape, spring barely) and plantations of the perennial biofuel crops Miscanthus x. giganteus (C4) and short rotation coppice (SRC) willow (Salix sp.,C3). Ecosystem light and temperature response functions were used to analyse and compare temporal trends and spatial variations in NEE across the three land covers. All three crops were net in situ sinks for atmospheric CO2 but were characterised by large temporal and between site variability in NEE. Environmental and biological controls driving the spatial and temporal variations in CO2 exchange processes, as well as the influences of land management, will be analysed and discussed.

  8. Cold hardiness research on agricultural and horticultural crops in Finland

    Directory of Open Access Journals (Sweden)

    L. LINDÉN

    2008-12-01

    Full Text Available This paper represents an overview of cold hardiness research conducted on agricultural and horticultural crops, as well as on amenity plants in Finland. Inadequate freezing tolerance and/or winter hardiness often prevents introduction of new species and cultivars to Finland. Field observations on winter hardiness and more recently the results from laboratory freezing tests, have assisted breeders to select hardy genotypes. Research approaches for agricultural crops have evolved from observations on winter and frost damage to studies on molecular mechanisms of cold acclimation and freezing injury. The results of experiments on survival of winter cereals, grasses and clovers and frost tolerance of potato and turnip rape are discussed. The studies conducted on horticultural crops, including apple, strawberry, raspberry, currants, blueberry, sea buckthorn, perennial herbs as well as on ornamental trees and shrubs have included field evaluations of cultivars, or selections for winter hardiness, and studies on the effects of cultural management practices on winter survival. During the last decade detailed studies including controlled freezing tests have provided tools to assist in explanation of the underlying mechanisms of cold hardiness also in horticultural plants. ;

  9. 75 FR 59057 - Common Crop Insurance Regulations, Cotton Crop Insurance Provisions and Macadamia Nut Crop...

    Science.gov (United States)

    2010-09-27

    ... Insurance Corporation 7 CFR Part 457 RIN 0563-AB96 Common Crop Insurance Regulations, Cotton Crop Insurance Provisions and Macadamia Nut Crop Insurance Provisions; Correction AGENCY: Federal Crop Insurance Corporation... make corrections relating to the insurance of cotton and macadamia nuts that published March 30, 2010...

  10. Teale California shoreline

    Data.gov (United States)

    California Department of Resources — California Spatial Information System (CaSIL) is a project designed to improve access to geo-spatial and geo-spatial related data information throughout the state of...

  11. Mediterranean California, Chapter 13

    Science.gov (United States)

    M.E. Fenn; E.B. Allen; L.H. Geiser

    2011-01-01

    The Mediterranean California ecoregion (CEC 1997; Fig 2.2) encompasses the greater Central Valley, Sierra foothills, and central coast ranges of California south to Mexico and is bounded by the Pacific Ocean, Sierra Nevada Mountains and Mojave Desert.

  12. California Condor Critical Habitat

    Data.gov (United States)

    California Department of Resources — These Data identify (in general) the areas where critical habitat for the California Condor occur. Critical habitat for the species consists of the following 10...

  13. Expressed sequence tag-derived microsatellite markers of perennial ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Studer, Bruno; Asp, Torben; Frei, Ursula

    2008-01-01

    An expressed sequence tag (EST) library of the key grassland species perennial ryegrass (Lolium perenne L.) has been exploited as a resource for microsatellite marker development. Out of 955 simple sequence repeat (SSR) containing ESTs, 744 were used for primer design. Primer amplification...... genotypes included in the original screening and revealed SSR polymorphisms for 143 ESTs. Here, we report on 464 EST-derived SSR primer sequences of perennial ryegrass established in laboratory assays, providing a dedicated tool for marker assisted breeding and comparative mapping within and among forage...

  14. Seed bank persistence of genetically modified canola in California.

    Science.gov (United States)

    Munier, Douglas J; Brittan, Kent L; Lanini, W Thomas

    2012-07-01

    Canola, which is genetically modified (GM) for tolerance to glyphosate, has the potential to become established as a new glyphosate resistant weed, thus reducing the effectiveness of glyphosate. Volunteer from dormant canola seeds produced thousands of plants per hectare in the fourth year (2011) following a 2007 crop harvest. This occurred with no additional canola seed production since the 2007 harvest. Volunteer plants following harvests of annual crops are typically only a problem for the first year after harvest. In California, glyphosate is the core herbicide on over a million hectares of high value row, tree, and vine crops and new glyphosate resistant weeds reduce the effectiveness of glyphosate. The combination of dormant seed and herbicide resistance makes GM glyphosate-resistant canola a new and difficult California weed which was first observed in the winter of 2009.

  15. Nitrous oxide, carbon dioxide and methane emissions from irrigated cropping systems as influenced by legumes, manure and fertilizer

    Energy Technology Data Exchange (ETDEWEB)

    Ellert, B.H.; Janzen, H.H. [Agriculture and Agri-Food Canada, Lethbridge, AB (Canada)

    2008-04-15

    Irrigated crops in Alberta require higher inputs of nitrogen (N) than rainfed crops. The aim of the study was to determine emissions of nitrous oxide (N{sub 2}O) from the soils of irrigated cropping systems that used inorganic fertilizer N at a site in Alberta. The study measured carbon dioxide (CO{sub 2}) and methane (CH{sub 4}) levels in order to determine net greenhouse gas (GHG) emissions. The exchange of gases between the atmosphere and soil in selected treatments was measured in order to compare the effects of contrasting N inputs. Fluxes were measured bi-weekly from spring 2001 to spring 2004. The time period included annual and perennial legume crops; the termination of a perennial forage crop; manure application; and 2 growing seasons of test crops. Soil surface fluxes were measured using PVC chambers equipped with thermocouples. Gas samples were measured using gas chromatography. A linear least squares method was used to calculate gas concentrations. Results showed that soil CO{sub 2} and N{sub 2}O production rates were intertwined after legume production or manure application, but decoupled during early spring bursts of N{sub 2}O production. Higher soil CO{sub 2} emissions with alfalfa and manure-amended soils suggested that soil oxygen consumption during high CO{sub 2} emission periods may promote N{sub 2}O emissions. Appreciable proportions of N{sub 2}O were emitted outside the growing season. Results suggested that N{sub 2}O leakage is an inevitable hazard of crop production. The study highlighted the importance of understanding and quantifying N{sub 2}O emissions from intensive cropping systems. 22 refs., 4 tabs., 6 figs.

  16. Addressing crop interactions within cropping systems in LCA

    DEFF Research Database (Denmark)

    Goglio, Pietro; Brankatschk, Gerhard; Knudsen, Marie Trydeman

    2018-01-01

    management and emissions, and (3) functional unit issues. The LCA approaches presented are as follows: cropping system, allocation approaches, crop-by-crop approach, and combined approaches. The various approaches are described together with their advantages and disadvantages, applicability......, and cannot be applied for intercropping and agroforestry systems. The allocation approaches take into account the cropping system effects by establishing a mathematical relationship between crops present in the cropping systems. The model for integrative life-cycle assessment in agriculture (MiLA) approach...

  17. Optimizing the number of consecutive seed harvests in red fescue (Festuca rubra L.) and perennial ryegrass (Lolium perenne L.) for yield, yield components and economic return

    DEFF Research Database (Denmark)

    Deleuran, Lise Christina; Kristensen, Kristian; Gislum, René

    2013-01-01

    , respectively, of perennial ryegrass (Lolium perenne L.) and red fescue (Festuca rubra L.) and their optimum number of growing seasons in terms of yield, selected yield components and economic gain. Three harvest years gave the maximum yield in the red fescue type with long stolons (cv. Pernille......Crop production must continuously be adjusted according to economic return and fluctuating prices on inputs versus harvested plant products and calls for continuous revision of the crop rotation and flexible management systems. This study describes grass seed production of three different types...... harvest and a continuous decline in seed yield is observed from the first to the fifth harvest year in this cultivar. Yet, when the economic incentive was calculated it was found that optimum harvest years cannot be determined by yield considerations alone. A combination of high grass seed price and low...

  18. Plant biotechnology: transgenic crops.

    Science.gov (United States)

    Shewry, Peter R; Jones, Huw D; Halford, Nigel G

    2008-01-01

    Transgenesis is an important adjunct to classical plant breeding, in that it allows the targeted manipulation of specific characters using genes from a range of sources. The current status of crop transformation is reviewed, including methods of gene transfer, the selection of transformed plants and control of transgene expression. The application of genetic modification technology to specific traits is then discussed, including input traits relating to crop production (herbicide tolerance and resistance to insects, pathogens and abiotic stresses) and output traits relating to the composition and quality of the harvested organs. The latter include improving the nutritional quality for consumers as well as the improvement of functional properties for food processing.

  19. The Biogeochemical Cycling of Nitrogen in Annual and Perennial Agroecosystems

    Science.gov (United States)

    Fortuna, A.; Cogger, C.

    2010-12-01

    Organic agricultural systems are dependent upon fertilizer amendments that undergo ammonification prior to the release of plant available nitrogen (N) as ammonium. Ammonia may be further transformed via nitrification to nitrate resulting in greater potential for leaching or volatilization. Additions of plant residue and animal amendments contribute to soil N and carbon pools improving soil quality and the potential for release of ammonium. Therefore, agricultural systems that relay on organic inputs as fertilizer sources must be monitored to insure stored nutrients are released during plant uptake to prevent N losses. Our experimental design allows us to determine the effects of several organic cropping systems and fertility regimes on plant available N, nitrification potential and nitrifier gene copy number g-1 dry soil across season in a grass ley and two annual systems receiving chicken manure or compost. Nitrification potentials measured via the shaken slurry method, KCl extractable N and ammonia oxidizing bacteria (AOB) and archaea (AOA) gene copy numbers g-1 dry soil measured via quantitative PCR were monitored. Nitrification potentials measured in March revealed increases in nitrification where compost had historically been applied (7.78 vs. 5.26 ± 0.856). Treatment affects were significant in June the closest date to application of amendments and when ammonification from soil N was optimal. Animal amendments were added yearly in annual systems (31.0 ± 2.91) vs every three years in the ley pasture (12.9 ± 2.91) resulting in a management effect. Copy numbers of AOB (2.69 x 108 ± 4.94 x 107) were greatest in plots receiving compost vs chicken manure. Preliminary measurements of AOA gene copy numbers reveal a similar trend to that of AOB. But, gene copy numbers of AOA (105 to 106) were lower than those of AOB. Nitrification potentials were not different across treatments in September, 11.8 ± 2.28. This research will contribute to the development of novel

  20. Greenhouse Gas Emissions Associated With Establishing Energy Crops

    Science.gov (United States)

    NiChonchubhair, Orlaith; Osborne, Bruce; Krol, Dominika; Williams, Mike; Jones, Mike; Lanigan, Gary

    2013-04-01

    of a dense canopy in its first year and correspondingly high net CO2 uptake, which increased further in the second year to a value close to that of year-3 Miscanthus. However, continued development of the Miscanthus crop to full maturity and maximum biomass yields is expected to enhance further the superior GHG sink strength of Miscanthus relative to RCG. This research highlights the high GHG efficiency of perennial biomass crops, which, combined with fossil fuel displacement during combustion, may present opportunities in the future for offsetting emissions in the agricultural sector.

  1. Greenhouse gas fluxes during growth of different bioenergy crops

    Science.gov (United States)

    Walter, K.; Don, A.; Flessa, H.

    2012-04-01

    gas budget of the anlysed crops. Emissions related to management activities and during fertilizer production have to be taken into account. Total emissions were related to the net energy yield of the different crops. Our first results indicate that perennial crops have the potential to reduce greenhouse gas emissions from bioenergy crop production as compared to annual crops due to its lower fertilizer demand.

  2. Water Savings of Crop Redistribution in the United States

    Directory of Open Access Journals (Sweden)

    Kyle Frankel Davis

    2017-01-01

    Full Text Available Demographic growth, changes in diet, and reliance on first-generation biofuels are increasing the human demand for agricultural products, thereby enhancing the human pressure on global freshwater resources. Recent research on the food-water nexus has highlighted how some major agricultural regions of the world lack the water resources required to sustain current growth trends in crop production. To meet the increasing need for agricultural commodities with limited water resources, the water use efficiency of the agricultural sector must be improved. In this regard, recent work indicates that the often overlooked strategy of changing the crop distribution within presently cultivated areas offers promise. Here we investigate the extent to which water in the United States could be saved while improving yields simply by replacing the existing crops with more suitable ones. We propose crop replacement criteria that achieve this goal while preserving crop diversity, economic value, nitrogen fixation, and food protein production. We find that in the United States, these criteria would greatly improve calorie (+46% and protein (+34% production and economic value (+208%, with 5% water savings with respect to the present crop distribution. Interestingly, greater water savings could be achieved in water-stressed agricultural regions of the US such as California (56% water savings, and other western states.

  3. Cover crops support ecological intensification of arable cropping systems.

    Science.gov (United States)

    Wittwer, Raphaël A; Dorn, Brigitte; Jossi, Werner; van der Heijden, Marcel G A

    2017-02-03

    A major challenge for agriculture is to enhance productivity with minimum impact on the environment. Several studies indicate that cover crops could replace anthropogenic inputs and enhance crop productivity. However, so far, it is unclear if cover crop effects vary between different cropping systems, and direct comparisons among major arable production systems are rare. Here we compared the short-term effects of various cover crops on crop yield, nitrogen uptake, and weed infestation in four arable production systems (conventional cropping with intensive tillage and no-tillage; organic cropping with intensive tillage and reduced tillage). We hypothesized that cover cropping effects increase with decreasing management intensity. Our study demonstrated that cover crop effects on crop yield were highest in the organic system with reduced tillage (+24%), intermediate in the organic system with tillage (+13%) and in the conventional system with no tillage (+8%) and lowest in the conventional system with tillage (+2%). Our results indicate that cover crops are essential to maintaining a certain yield level when soil tillage intensity is reduced (e.g. under conservation agriculture), or when production is converted to organic agriculture. Thus, the inclusion of cover crops provides additional opportunities to increase the yield of lower intensity production systems and contribute to ecological intensification.

  4. Cover crops support ecological intensification of arable cropping systems

    Science.gov (United States)

    Wittwer, Raphaël A.; Dorn, Brigitte; Jossi, Werner; van der Heijden, Marcel G. A.

    2017-02-01

    A major challenge for agriculture is to enhance productivity with minimum impact on the environment. Several studies indicate that cover crops could replace anthropogenic inputs and enhance crop productivity. However, so far, it is unclear if cover crop effects vary between different cropping systems, and direct comparisons among major arable production systems are rare. Here we compared the short-term effects of various cover crops on crop yield, nitrogen uptake, and weed infestation in four arable production systems (conventional cropping with intensive tillage and no-tillage; organic cropping with intensive tillage and reduced tillage). We hypothesized that cover cropping effects increase with decreasing management intensity. Our study demonstrated that cover crop effects on crop yield were highest in the organic system with reduced tillage (+24%), intermediate in the organic system with tillage (+13%) and in the conventional system with no tillage (+8%) and lowest in the conventional system with tillage (+2%). Our results indicate that cover crops are essential to maintaining a certain yield level when soil tillage intensity is reduced (e.g. under conservation agriculture), or when production is converted to organic agriculture. Thus, the inclusion of cover crops provides additional opportunities to increase the yield of lower intensity production systems and contribute to ecological intensification.

  5. Cultivar by environment effects of perennial ryegrass cultivars selected for high water soluble carbohydrates managed under differing precipitation levels

    Science.gov (United States)

    Historic results of perennial ryegrass (Lolium perenne L.) breeding include improved disease resistance, biomass, and nutritional quality. Yet, lack of tolerance to water stress limits its wise use. Recent efforts to increase water soluble carbohydrate (WSC) content in perennial ryegrass may incre...

  6. The interplay between shifts in biomass allocation and costs of reproduction in four grassland perennials under simulated successional change

    NARCIS (Netherlands)

    Jongejans, E.; Kroon, de H.; Berendse, F.

    2006-01-01

    When perennial herbs face the risk of being outcompeted in the course of succession, they are hypothesized to either increase their biomass allocation to flowers and seeds or to invest more in vegetative growth. We tested these hypotheses in a 3-year garden experiment with four perennials

  7. Resistance of Endophyte-Infected Plants of Tall Fescue and Perennial Ryegrass to the Russian Wheat Aphid (Homoptera: Aphididae)

    Science.gov (United States)

    S.L. Clement; K.S. Pike; W.J. Kaiser; A. Dan Wilson

    1991-01-01

    Fewer aphids of the Russian wheat aphid, (Mordvilko), were found on tall fescue and perennial ryegrass plants harboring systemic fungal endophytes than on endophyte-free plants in laboratory tests. These results indicate that enhanced resistance in some perennial grasses to D. noxia is associated with the presence of endophytic fungi.

  8. Global Simulation of Bioenergy Crop Productivity: Analytical Framework and Case Study for Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Shujiang [ORNL; Kline, Keith L [ORNL; Nair, S. Surendran [University of Tennessee, Knoxville (UTK); Nichols, Dr Jeff A [ORNL; Post, Wilfred M [ORNL; Brandt, Craig C [ORNL; Wullschleger, Stan D [ORNL; Wei, Yaxing [ORNL; Singh, Nagendra [ORNL

    2013-01-01

    A global energy crop productivity model that provides geospatially explicit quantitative details on biomass potential and factors affecting sustainability would be useful, but does not exist now. This study describes a modeling platform capable of meeting many challenges associated with global-scale agro-ecosystem modeling. We designed an analytical framework for bioenergy crops consisting of six major components: (i) standardized natural resources datasets, (ii) global field-trial data and crop management practices, (iii) simulation units and management scenarios, (iv) model calibration and validation, (v) high-performance computing (HPC) simulation, and (vi) simulation output processing and analysis. The HPC-Environmental Policy Integrated Climate (HPC-EPIC) model simulated a perennial bioenergy crop, switchgrass (Panicum virgatum L.), estimating feedstock production potentials and effects across the globe. This modeling platform can assess soil C sequestration, net greenhouse gas (GHG) emissions, nonpoint source pollution (e.g., nutrient and pesticide loss), and energy exchange with the atmosphere. It can be expanded to include additional bioenergy crops (e.g., miscanthus, energy cane, and agave) and food crops under different management scenarios. The platform and switchgrass field-trial dataset are available to support global analysis of biomass feedstock production potential and corresponding metrics of sustainability.

  9. Traits to ecosystems: The ecological sustainability challenge when developing future energy crops

    Directory of Open Access Journals (Sweden)

    Martin eWeih

    2014-05-01

    Full Text Available Today we are undertaking great efforts to improve biomass production and quality traits of energy crops. Major motivation for developing those crops is based on environmental and ecological sustainability considerations, which however often are de-coupled from the trait-based crop improvement programs. It is now time to develop appropriate methods to link crop traits to production system characteristics set by the plant and the biotic communities influencing it; and to the ecosystem processes affecting ecological sustainability. The relevant ecosystem processes involve the net productivity in terms of biomass and energy yields, the depletion of energy-demanding resources (e.g. nitrogen, N, the carbon dynamics in soil and atmosphere, and the resilience and temporal stability of the production system. In a case study, we compared aspects of N use efficiency in various varieties of an annual (spring wheat and perennial (Salix energy crop grown under two nutrient regimes in Sweden. For example, we found considerable variation among crops, varieties and nutrient regimes in the energy yield per plant-internal N (MJ g-1 yr-1, which would result in different N resource depletion per unit energy produced.

  10. Biocrude crop production in arid lands. [Calotropis procera, Chrysothamus paniculatus, Euphorbia lathyris, Grindelia camporum

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, S.P.; Kingsolver, B.E.; Hoffmann, J.J.

    1983-01-01

    Published and unpublished estimates of land and water requirements and energy yield were used to prepare energy budgets for 4 potential biocrude (liquid fuel) crops in the SW USA: the perennials Calotropis procera and Chrysothamnus paniculatus and the annuals Euphorbia lathyris and Grindelia camporum. Estimated annual costs are examined and discussed for an operation processing 300,000 t/yr. The cheapest energy was produced by C. paniculatus, although it required the largest land area. The paper emphasizes that selecting for biocrude content (biomass quality) of plants may be at the expense of productivity (quantity) since the 2 have been shown to be inversely related in many cases. 8 references.

  11. Biotechnology Towards Energy Crops.

    Science.gov (United States)

    Margaritopoulou, Theoni; Roka, Loukia; Alexopoulou, Efi; Christou, Myrsini; Rigas, Stamatis; Haralampidis, Kosmas; Milioni, Dimitra

    2016-03-01

    New crops are gradually establishing along with cultivation systems to reduce reliance on depleting fossil fuel reserves and sustain better adaptation to climate change. These biological assets could be efficiently exploited as bioenergy feedstocks. Bioenergy crops are versatile renewable sources with the potential to alternatively contribute on a daily basis towards the coverage of modern society's energy demands. Biotechnology may facilitate the breeding of elite energy crop genotypes, better suited for bio-processing and subsequent use that will improve efficiency, further reduce costs, and enhance the environmental benefits of biofuels. Innovative molecular techniques may improve a broad range of important features including biomass yield, product quality and resistance to biotic factors like pests or microbial diseases or environmental cues such as drought, salinity, freezing injury or heat shock. The current review intends to assess the capacity of biotechnological applications to develop a beneficial bioenergy pipeline extending from feedstock development to sustainable biofuel production and provide examples of the current state of the art on future energy crops.

  12. Mycorrhiza and crop production

    Energy Technology Data Exchange (ETDEWEB)

    Hayman, D.S.

    1980-10-09

    This article describes recent research with vesicular-arbuscular mycorrhiza, a symbiotic fungus-root association. The suggestion that the symbiotic association may be harnessed to achieve more economical use of phosphate fertilizers is discussed and the results from various test crops are given.

  13. Association of candidate genes with drought tolerance traits in diverse perennial ryegrass accessions

    Science.gov (United States)

    Xiaoqing Yu; Guihua Bai; Shuwei Liu; Na Luo; Ying Wang; Douglas S. Richmond; Paula M. Pijut; Scott A. Jackson; Jianming Yu; Yiwei. Jiang

    2013-01-01

    Drought is a major environmental stress limiting growth of perennial grasses in temperate regions. Plant drought tolerance is a complex trait that is controlled by multiple genes. Candidate gene association mapping provides a powerful tool for dissection of complex traits. Candidate gene association mapping of drought tolerance traits was conducted in 192 diverse...

  14. Perennial ryegrass for dairy cows: Intake, milk production and nitrogen utilization

    NARCIS (Netherlands)

    Tas, B.M.

    2005-01-01

    Keywords: perennial ryegrass, dairy cows, intake, digestibility milk production, nitrogen utilisation.In the Netherlands, grass is one of the main roughages in the diet of high productive dairy cows. Grass is associated with two main problems: the limited dry matter intake (DMI)

  15. On the relation between tillering, leaf area dynamics and growth of perennial ryegrass (Lolium perennne L.)

    NARCIS (Netherlands)

    Loo, van E.N.

    1993-01-01

    Modern intensively managed grasslands are subject to sward deterioration as a result of urine scorching, treading, winter mortality and late mowing or grazing. The major species in Dutch grasslands is perennial ryegrass. Deterioration consists of a decreasing presence of this species through death

  16. 30 CFR 784.28 - Surface activities in or adjacent to perennial or intermittent streams.

    Science.gov (United States)

    2010-07-01

    ... or intermittent streams. 784.28 Section 784.28 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... intermittent streams. (a) Applicability. (1) In general. Except as otherwise provided in paragraph (a)(2) of... surface activities in perennial or intermittent streams or on the surface of lands within 100 feet...

  17. Defining perennial, intermittent and ephemeral channels in eastern Kentucky: application to forestry best management practices

    Science.gov (United States)

    J. R. Svec; R. K. Kolka; J. W. Stringer

    2003-01-01

    In Kentucky stream classification is used to determine which forestry best management practice (BMP) to apply in riparian zones. Kentucky defines stream classes as follows (Stringer and others 1998): a) perennial streams that hold water throughout the year, b) intermittent streams that hold water during wet portions of the year, and c) ephemeral channels that hold...

  18. Genomic Variance Estimation Based on Genotyping-by-Sequencing with Different Coverage in Perennial Ryegrass

    DEFF Research Database (Denmark)

    Ashraf, Bilal; Fé, Dario; Jensen, Just

    2014-01-01

    on optimizing methods and models utilizing F2 family phenotype records and NGS information from F2 family pools in perennial ryegrass. Genomic variance was estimated using genomic relationship matrices based on different coverage depths to verify effects of coverage depth. Example traits were seed yield, rust...

  19. Genomic Selection Using Genotyping-By-Sequencing Data with Different Coverage Depth in Perennial Ryegrass

    DEFF Research Database (Denmark)

    Cericola, Fabio; Fé, Dario; Janss, Luc

    investigated how this reduction of the coverage depth affects the genomic relationship matrices used to estimated breeding value of F2 family pools in perennial ryegrass. A total of 995 families were genotyped via GBS providing more than 1.8M allele frequency estimates for each family with an average coverage...

  20. Genetic linkage mapping in an F2 perennial ryegrass population using DArT markers

    Czech Academy of Sciences Publication Activity Database

    Tomaszewski, C.; Byrne, S. L.; Foito, A.; Kildea, S.; Kopecký, David; Doležel, Jaroslav; Heslop-Harrison, J. S.; Stewart, D.; Barth, S.

    2012-01-01

    Roč. 131, č. 2 (2012), s. 345-349 ISSN 0179-9541 Institutional research plan: CEZ:AV0Z50380511 Keywords : Lolium perenne * perennial ryegrass * genetic map Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.175, year: 2012

  1. Cultivar effects of perennial ryegrass on herbage intake by grazing dairy cows

    NARCIS (Netherlands)

    Smit, H.J.

    2006-01-01

    Perennial ryegrass is the most abundant grass species in temperate climates. An increased herbage intake of dairy cows by breeding new cultivars could have a large potential impact on agriculture. The effects of cultivars on sward structure, nutritive value, physical characteristics and disease

  2. Molecular mechanisms responsive to dehydration may impact the invasiveness of perennial weeds under global climate change

    Science.gov (United States)

    Leafy spurge is an invasive perennial weed in the great plains of the US and Canada. The ability of this herbaceous weed to regenerate new shoot growth from an abundance of crown and root buds after severe abiotic stress is critical for survival. Due to its adaptable and aggressive nature, global cl...

  3. Returning succession to downy brome dominated rangelands: roadblocks to perennial grass establishment

    Science.gov (United States)

    The most common cause of successional retrogression in the Great Basin is wildfires fueled by downy brome (Bromus tectorum). Downy brome invasion has reduced fire intervals from an estimated 60-100 years down to 5-10 years. Our previous research found that establishment of long-lived perennial grass...

  4. Silicon induced systemic defense responses in perennial ryegrass against Magnaporthe oryzae infection

    Science.gov (United States)

    Sustainable integrated disease management for gray leaf spot of perennial ryegrass may involve use of plant defense elicitors with compatible traditional fungicides to reduce disease incidence and severity. Silicon (Si) is a potential inducer or modulator of plant defenses against different pathogen...

  5. Seasonal Variation of Provitamin D2 and Vitamin D2 in Perennial Ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Jäpelt, Rie Bak; Didion, Thomas; Smedsgaard, Jørn

    2011-01-01

    Ergosterol (provitamin D(2)) is converted to vitamin D(2) in grass by exposure to UV light. Six varieties of perennial ryegrass (Lolium perenne L.) were harvested four times during the season, and the contents of vitamin D(2) and ergosterol were analyzed by a sensitive and selective liquid...

  6. An object-oriented model of the morphological development and digestibility of perennial ryegrass

    NARCIS (Netherlands)

    Groot, J.C.J.; Lantinga, E.A.

    2004-01-01

    An object-oriented simulation model was developed to integrate detailed analyses of perennial ryegrass (Lolium perenne) plant part dimensions, and their mass, cell wall content (CWC) and cell wall digestibility (CWD). The model was validated against data from two field experiments, carried out in

  7. Comparison of signaling interactions determining annual and perennial plant growth in response to low temperature

    Directory of Open Access Journals (Sweden)

    Astrid eWingler

    2015-01-01

    Full Text Available Low temperature inhibits plant growth despite the fact that considerable rates of photosynthetic activity can be maintained. Instead of lower rates of photosynthesis, active inhibition of cell division and expansion is primarily responsible for reduced growth. This results in sink limitation and enables plants to accumulate carbohydrates that act as compatible solutes or are stored throughout the winter to enable re-growth in spring. Regulation of growth in response to temperature therefore requires coordination with carbon metabolism, e.g. via the signaling metabolite trehalose-6-phosphate. The phytohormones gibberellins (GA and jasmonate (JA play an important role in regulating growth in response to temperature. Growth restriction at low temperature is mainly mediated by DELLA proteins, whose degradation is promoted by GA. For annual plants, it has been shown that the GA/DELLA pathway interacts with JA signaling and C-repeat binding factor (CBF dependent cold acclimation, but these interactions have not been explored in detail for perennials. Growth regulation in response to seasonal factors is, however, particularly important in perennials, especially at high latitudes. In autumn, growth cessation in trees is caused by shortening of the daylength in interaction with phytohormone signaling. In perennial grasses seasonal differences in the sensitivity to GA may enable enhanced growth in spring. This review provides an overview of the signaling interactions that determine plant growth at low temperature and highlights gaps in our knowledge, especially concerning the seasonality of signaling responses in perennial plants.

  8. Assessing variability of water quality in a groundwater-fed perennial ...

    Indian Academy of Sciences (India)

    Assessing variability of water quality in a groundwater-fed perennial lake of Kashmir Himalayas using linear geostatistics. S Sarah1,∗, Gh Jeelani2 and Shakeel Ahmed1. 1IFCGR, National Geophysical Research Institute, CSIR, Hyderabad 500 606, India. 2Department of Geology and Geophysics, University of Kashmir, ...

  9. Forages and pastures symposium: fungal endophytes of tall fescue and perennial ryegrass: pasture friend or foe?

    Science.gov (United States)

    Young, C A; Hume, D E; McCulley, R L

    2013-05-01

    Tall fescue [Lolium arundinaceum (Schreb.) Darbysh. syn. Festuca arundinacea Schreb.] and perennial ryegrass (Lolium perenne L.) are important perennial forage grasses utilized throughout the moderate- to high-rainfall temperate zones of the world. These grasses have coevolved with symbiotic fungal endophytes (Epichloë/Neotyphodium spp.) that can impart bioactive properties and environmental stress tolerance to the grass compared with endophyte-free individuals. These endophytes have proven to be very important in pastoral agriculture in the United States, New Zealand, and Australia, where forage grasses are the principal feed for grazing ruminants. In this review, we describe the biology of these grass-endophyte associations and implications for the livestock industries that are dependent on these forages. Endophyte alkaloid production is put in context with endophyte diversity, and we illustrate how this has facilitated utilization of grasses infected with different endophyte strains that reduce livestock toxicity issues. Utilization of tall fescue and use of perennial ryegrass in the United States, New Zealand, and Australia are compared, and management strategies focused predominantly on the success of endophyte-infected perennial ryegrass in New Zealand and Australia are discussed. In addition, we consider the impact of grass-endophyte associations on the sustainability of pasture ecosystems and their likely response to future changes in climate.

  10. Freeze tolerance of perennial ryegrass and implications for future species distribution.

    Science.gov (United States)

    Winter hardiness is one of the factors limiting the use of the palatable and productive cool-season forage grass Lolium perenne L, perennial ryegrass, in the northeastern United States. We performed a screening study to compare freeze tolerance, one component of winter hardiness, among thirteen comm...

  11. Establishment of the invasive perennial Vincetoxicum rossicum across a disturbance gradient in New York State, USA

    Science.gov (United States)

    Vincetoxicum rossicum (pale swallow-wort) is a non-native, perennial, herbaceous vine in the Apocynaceae. The species’ abundance is steadily increasing in the northeastern United States and southeastern Canada. Little is known about Vincetoxicum species recruitment and growth. Therefore, we condu...

  12. Behavior Performance of Diuraphis noxia (Homoptera: Aphididae) on Fungal Endophyte-Infected and Uninfected Perennial Ryegrass

    Science.gov (United States)

    S.L. Clement; D.G. Lester; A. Dan Wilson; K.S. Pike

    1992-01-01

    The behavior and performance of the Russian wheat aphid, Diuraphis noxia (Mordvilko), on fungal endophyte-infected and endophyte-free perennial ryegrass, Lolium perenne L., was investigated in the laboratory and field. Aphids did not select endophyte-free over endophyte-infected leaf sheaths and stem segments in petri dish preference tests....

  13. Natural enemies of perennial pepperweed, lepidium latifolium L., in its introduced range

    Science.gov (United States)

    Perennial pepperweed, Lepidium latifolium L., is a member of the Brassicaceae native to Eurasia. It was unintentionally introduced to North America in the early 1900s, where it has since spread over millions of acres. This weed is an aggressive invader of wetlands, meadows, roadsides, and agricult...

  14. Minimal genetic diversity in the facultatively outcrossing perennial pepperweed (Lepidium latifolium) invasion

    Science.gov (United States)

    Perennial pepperweed (Lepidium latifolium L.) is a Eurasian plant species that is invasive in North America. The invasion often forms large, dense monocultural stands. We investigated the genetic diversity along transects in dense populations in the western USA using Amplified Fragment Length Polymo...

  15. Is genetic engineering ever going to take off in forage, turf and bioenergy crop breeding?

    Science.gov (United States)

    Wang, Zeng-Yu; Brummer, E. Charles

    2012-01-01

    Background Genetic engineering offers the opportunity to generate unique genetic variation that is either absent in the sexually compatible gene pool or has very low heritability. The generation of transgenic plants, coupled with breeding, has led to the production of widely used transgenic cultivars in several major cash crops, such as maize, soybean, cotton and canola. The process for regulatory approval of genetically engineered crops is slow and subject to extensive political interference. The situation in forage grasses and legumes is more complicated. Scope Most widely grown forage, turf and bioenergy species (e.g. tall fescue, perennial ryegrass, switchgrass, alfalfa, white clover) are highly self-incompatible and outcrossing. Compared with inbreeding species, they have a high potential to pass their genes to adjacent plants. A major biosafety concern in these species is pollen-mediated transgene flow. Because human consumption is indirect, risk assessment of transgenic forage, turf and bioenergy species has focused on their environmental or ecological impacts. Although significant progress has been made in genetic modification of these species, commercialization of transgenic cultivars is very limited because of the stringent and costly regulatory requirements. To date, the only transgenic forage crop deregulated in the US is ‘Roundup Ready’ (RR) alfalfa. The approval process for RR alfalfa was complicated, involving several rounds of regulation, deregulation and re-regulation. Nevertheless, commercialization of RR alfalfa is an important step forward in regulatory approval of a perennial outcrossing forage crop. As additional transgenic forage, turf and bioenergy crops are generated and tested, different strategies have been developed to meet regulatory requirements. Recent progress in risk assessment and deregulation of transgenic forage and turf species is summarized and discussed. PMID:22378838

  16. Drought Effects on Agricultural Yield: Comparison Across Regions and Crop Types

    Science.gov (United States)

    Daryanto, S.; Wang, L.; Jacinthe, P. A.

    2014-12-01

    Global agricultural production is dominated by rainfed agriculture, and is therefore prone to disruption from climate extreme weathers. These uncertainties become more problematic when considering the projection of increased drought frequency suggested by several climate models for various world regions. Curiously, few regional analyses of drought impact of food production have been attempted. We collated and analyzed data from the last 25 years to disentangle the effects of drought (i.e. timing, intensity and duration) on agricultural production in different eco-regions and with varying crop types. Our preliminary results suggested greater yield reduction in annual (-21.5%) than perennial plants (-16%), in C4 (-21%) compared to C3 crops (-17%), and when drought occurred during generative (i.e. flowering until maturity; -16.5%) than vegetative stage (-15.5%). Although drought caused similar amounts of yield reduction in both tropical and subtropical regions (i.e. -17%), it carries a greater food security risk in the tropics due to inherently low productivity (i.e. less than half than in the subtropical regions). Consequently, cultivating drought-resistant C3 perennial plants (e.g. sweet potato and cassava) in the tropics could prove a viable adaptive strategy to mitigate the effects of climate variability. In addition, these crops have limited input requirements, are well adapted to nutrient-poor Oxisols and Ultisols of the tropics, and generally outyield cereal crops in the region. Our analysis is ongoing and needs to take into account agronomic traits (e.g. water requirement), as well as the energy and nutritional values (e.g. protein, minerals) of alternative crops. Our results could inform the selection and development of new cultivars for the drought-prone regions of the world.

  17. 78 FR 17606 - Common Crop Insurance Regulations; Arizona-California Citrus Crop Insurance Provisions

    Science.gov (United States)

    2013-03-22

    ... human environment, health, or safety. Therefore, neither an Environmental Assessment nor an... Commodity Type A Specified. Lemons No Commodity Type B Specified. Oranges Navel C Oranges Valencia D Oranges... Oranges 38 Container 58 Lemons 40 Container 59 Grapefruit 32 Container 63 Mandarins/Tangerines.... 25...

  18. Virus-based transient expression vectors for woody crops: a new frontier for vector design and use.

    Science.gov (United States)

    Dawson, William O; Folimonova, Svetlana Y

    2013-01-01

    Virus-based expression vectors are commonplace tools for the production of proteins or the induction of RNA silencing in herbaceous plants. This review considers a completely different set of uses for viral vectors in perennial fruit and nut crops, which can be productive for periods of up to 100 years. Viral vectors could be used in the field to modify existing plants. Furthermore, with continually emerging pathogens and pests, viral vectors could express genes to protect the plants or even to treat plants after they become infected. As technologies develop during the life span of these crops, viral vectors can be used for adding new genes as an alternative to pushing up the crop and replanting with transgenic plants. Another value of virus-based vectors is that they add nothing permanently to the environment. This requires that effective and stable viral vectors be developed for specific crops from endemic viruses. Studies using viruses from perennial hosts suggest that these objectives could be accomplished.

  19. Southwest Regional Climate Hub and California Subsidiary Hub assessment of climate change vulnerability and adaptation and mitigation strategies

    Science.gov (United States)

    Emile Elias; Caiti Steele; Kris Havstad; Kerri Steenwerth; Jeanne Chambers; Helena Deswood; Amber Kerr; Albert Rango; Mark Schwartz; Peter Stine; Rachel Steele

    2015-01-01

    This report is a joint effort of the Southwest Regional Climate Hub and the California Subsidiary Hub (Sub Hub). The Southwest Regional Climate Hub covers Arizona, California, Hawai‘i and the U.S. affiliated Pacific Islands, Nevada, New Mexico, and Utah and contains vast areas of western rangeland, forests, and high-value specialty crops (Figure 1). The California Sub...

  20. Governing the GM crop revolution

    OpenAIRE

    Paarlberg, Robert L.

    2000-01-01

    Will developing countries adopt policies that promote the planting of genetically modified (GM) crops, or will they select policies that slow the spread of the GM crop revolution? The evidence so far is mixed. In some prominent countries such as China, policies are in place that encourage the independent development and planting of GM crops. Yet in a number of other equally prominent countries the planting of GM crops is not yet officially approved. The inclination of developing countries to ...

  1. Allelopathic cover crop prior to seeding is more important than subsequent grazing/mowing in grassland establishment

    Science.gov (United States)

    Milchunas, Daniel G.; Vandever, Mark W.; Ball, Leonard O.; Hyberg, Skip

    2011-01-01

    The effects of grazing, mowing, and type of cover crop were evaluated in a previous winter wheat–fallow cropland seeded to grassland under the Conservation Reserve Program in eastern Colorado. Prior to seeding, the fallow strips were planted to forage sorghum or wheat in alternating strips (cover crops), with no grazing, moderate to heavy grazing, and mowing (grazing treatments) superimposed 4 yr after planting and studied for 3 yr. Plots previously in wheat had more annual and exotic species than sorghum plots. Concomitantly, there were much greater abundances of perennial native grass and all native species in sorghum than wheat cropped areas. The competitive advantage gained by seeded species in sorghum plots resulted in large increases in rhizomatous western wheatgrass. Sorghum is known to be allelopathic and is used in crop agriculture rotations to suppress weeds and increase crop yields, consistent with the responses of weed and desired native species in this study. Grazing treatment had relatively minor effects on basal and canopy cover composition of annual or exotic species versus perennial native grass or native species. Although grazing treatment never was a significant main effect, it occasionally modified cover crop or year effects. Opportunistic grazing reduced exotic cheatgrass by year 3 but also decreased the native palatable western wheatgrass. Mowing was a less effective weed control practice than grazing. Vegetative basal cover and aboveground primary production varied primarily with year. Common management practices for revegetation/restoration currently use herbicides and mowing as weed control practices and restrict grazing in all stages of development. Results suggest that allelopathic cover crop selection and opportunistic grazing can be effective alternative grass establishment and weed control practices. Susceptibility, resistance, and interactions of weed and seeded species to allelopathic cover species/cultivars may be a fruitful area

  2. Effects of Stocking Rate on the Variability of Peak Standing Crop in a Desert Steppe of Eurasia Grassland

    Science.gov (United States)

    Wang, Zhongwu; Jiao, Shuying; Han, Guodong; Zhao, Mengli; Ding, Haijun; Zhang, Xinjie; Wang, Xiaoliang; Ayers, Eldon L.; Willms, Walter D.; Havsatad, Kris; A, Lata; Liu, Yongzhi

    2014-02-01

    Proper grazing management practices can generate corresponding compensatory effects on plant community production, which may reduce inter-annual variability of productivity in some grassland ecosystems. However, it remains unclear how grazing influences plant community attributes and the variability of standing crop. We examined the effects of sheep grazing at four stocking rate treatments [control, 0 sheep ha-1 month-1; light (LG), 0.15 sheep ha-1 month-1; moderate (MG), 0.30 sheep ha-1 month-1; and heavy (HG), 0.45 sheep ha-1 month-1] on standing crop at the community level and partitioned by species and functional groups, in the desert steppe of Inner Mongolia, China. The treatments were arranged in a completely randomized block design over a 9-year period. Standing crop was measured every August from 2004 to 2012. Peak standing crop decreased ( P < 0.05) with increasing stocking rate; peak standing crop in the HG treatment decreased 40 % compared to the control. May-July precipitation explained at least 76 % of the variation in peak standing crop. MG and HG treatments resulted in a decrease ( P < 0.05) in shrubs, semi-shrubs, and perennials forbs, and an increase ( P < 0.05) in perennial bunchgrasses compared to the control. The coefficients of variation at plant functional group and species level in the LG and MG treatments were lower ( P < 0.05) than in the control and HG treatments. Peak standing crop variability of the control and HG community were greatest, which suggested that LG and MG have greater ecosystem stability.

  3. Multi-year strongest California drought from 500 m SNPP/VIIRS

    Science.gov (United States)

    Guo, W.; Kogan, F.

    2016-12-01

    Starting in 2006, the western United States was affected by a 10-year long mega-drought. Among 17 western states, California was the most severely drought-affected, especially in 2012-2015, when the area of stronger than moderate vegetation stress reached 70%. This drought had considerable impacts on California's environmental, economy and society. Currently, drought in the USA is monitored by the US Drought Monitor (USDM), which estimates drought area and intensity on an area with an effective resolution of around 30-by-30 km. California produces more than 90% of US fruits, vegetables, berries and nuts, which are grown on relatively small areas (200-500 acres, or 0.5 to 2 km²). Since most of these crops are irrigated, it is important to estimate crop conditions on the area comparable to the size of the planted crop. This paper demonstrates how the new 0.5-by-0.5 km Vegetation health (VH) technology (VH-500) developed from the data collected by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership (SNPP) satellite launched in 2011, monitors the current mega-drought in California, distinguishing drought-affected area with and without irrigation and estimating drought start/end, intensity, duration and impacts. The VH-500 method and data showed that California's vegetation was under medium-to-exceptional stress, especially in 2013 and 2014. However, in the middle of such intensive stress, in some of the 500-m areas of the Central Valley where principal crops are growing, vegetation experienced favorable conditions because some of these crops were irrigated. The VH-500 drought estimates showed general similarities with the assessed economic drought impacts (crop fallowing, employment loss and crop revenue change) in California.

  4. 75 FR 35959 - Raisins Produced From Grapes Grown in California; Final Free and Reserve Percentages for 2009-10...

    Science.gov (United States)

    2010-06-24

    ... Agricultural Marketing Service 7 CFR Part 989 Raisins Produced From Grapes Grown in California; Final Free and Reserve Percentages for 2009-10 Crop Natural (Sun-Dried) Seedless Raisins AGENCY: Agricultural Marketing... regulation percentages of 85 percent free and 15 percent reserve for the 2009-10 crop of Natural (sun-dried...

  5. CROPS : high tech agricultural robots

    NARCIS (Netherlands)

    Bontsema, J.; Hemming, J.; Pekkeriet, E.J.

    2014-01-01

    In the EU-funded CROPS (Clever Robots for Crops) project high tech robots are developed for site-specific spraying and selective harvesting of fruit and fruit vegetables. The harvesting robots are being designed to harvest high-value crops such as greenhouse vegetables, fruits in orchards and grapes

  6. [Ecological effects of cover crops].

    Science.gov (United States)

    Liu, Xiaobing; Song, Chunyu; Herbert, Stephen J; Xing, Baoshan

    2002-03-01

    This paper reviewed the effects of cover crops in reducing soil loss, surface runoff, NO3- leaching and water pollution, and elucidated roles of cover crops in controlling pest insects, weeds and diseases, and increasing soil nutrients. The potential roles and appropriate application of cover crops in sustainable development of agriculture were also discussed.

  7. Exogenous classic phytohormones have limited regulatory effects on fructan and primary carbohydrate metabolism in perennial ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Anna eGasperl

    2016-01-01

    Full Text Available Fructans are polymers of fructose and one of the main constituents of water-soluble carbohydrates in forage grasses and cereal crops of temperate climates. Fructans are involved in cold and drought resistance, regrowth following defoliation and early spring growth, seed filling, have beneficial effects on human health and are used for industrial processes. Perennial ryegrass (Lolium perenne L. serves as model species to study fructan metabolism. Fructan metabolism is under the control of both synthesis by fructosyltransferases (FTs and breakdown through fructan exohydrolases (FEHs. The accumulation of fructans can be triggered by high sucrose levels and abiotic stress conditions such as drought and cold stress. However, detailed studies on the mechanisms involved in the regulation of fructan metabolism are scarce. Since different phytohormones, especially abscisic acid (ABA, are known to play an important role in abiotic stress responses, the possible short term regulation of the enzymes involved in fructan metabolism by the five classical phytohormones was investigated. Therefore, the activities of enzymes involved in fructan synthesis and breakdown, the expression levels for the corresponding genes and levels for water-soluble carbohydrates were determined following pulse treatments with ABA, auxin (AUX, ethylene (ET, gibberellic acid (GA or kinetin (KIN. The most pronounced fast effects were a transient increase of FT activities by AUX, KIN, ABA and ET, while minor effects were evident for 1-FEH activity with an increased activity in response to KIN and a decrease by GA. Fructan and sucrose levels were not affected. This observed discrepancy demonstrates the importance of determining enzyme activities to obtain insight into the physiological traits and ultimately the plant phenotype. The comparative analyses of activities for seven key enzymes of primary carbohydrate metabolism revealed no co-regulation between enzymes of the fructan and

  8. Salt resistant crop plants

    KAUST Repository

    Roy, Stuart J.

    2014-04-01

    Soil salinity is a major constraint to agriculture. To improve salinity tolerance of crops, various traits can be incorporated, including ion exclusion, osmotic tolerance and tissue tolerance. We review the roles of a range of genes involved in salt tolerance traits. Different tissues and cells are adapted for specific and often diverse function, so it is important to express the genes in specific cell-types and to pyramid a range of traits. Modern biotechnology (marker- assisted selection or genetic engineering) needs to be increasingly used to introduce the correct combination of genes into elite crop cultivars. Importantly, the effects of introduced genes need to be evaluated in the field to determine their effect on salinity tolerance and yield improvement.

  9. Salt resistant crop plants.

    Science.gov (United States)

    Roy, Stuart J; Negrão, Sónia; Tester, Mark

    2014-04-01

    Soil salinity is a major constraint to agriculture. To improve salinity tolerance of crops, various traits can be incorporated, including ion exclusion, osmotic tolerance and tissue tolerance. We review the roles of a range of genes involved in salt tolerance traits. Different tissues and cells are adapted for specific and often diverse function, so it is important to express the genes in specific cell-types and to pyramid a range of traits. Modern biotechnology (marker-assisted selection or genetic engineering) needs to be increasingly used to introduce the correct combination of genes into elite crop cultivars. Importantly, the effects of introduced genes need to be evaluated in the field to determine their effect on salinity tolerance and yield improvement. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. IMPORTANCE OF MAIZE CROPPING

    OpenAIRE

    Mohammed Dhary Yousif EL-JUBOURI

    2012-01-01

    The Corn, wheat and rice together are the main crops. It is a plant that responds well to chemical and organic fertilization and the irrigation. But compliance is sensitive to optimum sowing time and integrated control of weeds, pests and diseases (2). The maize is the most important plant product, from the point of view commercially and is used primarily as fodder. The maize is an important source of vegetable oil and has many applications in industry, the manufacture of diverse items: cosme...

  11. Bats in Agroecosytems around California's Central Coast

    Science.gov (United States)

    Wayne, A.

    2014-12-01

    Bats in agroecosystems around California's Central Coast: A full quarter of California's land area is farmland. Crops account for 32.5 billion of California's GDP. Insect control is a big problem for farmers, and California bats eat only insects, saving farmers an estimated 3 to $53 billion a year. As farmers maximize crop yield, they use more pesticides, herbicides, and fertilizers, which contaminate runoff streams that bats drink from. Also, pesticide use kills bats' sole food source: insects. My research objective was to find out how farm management practices and landscape complexity affect bat diversity and activity, and to see which one affects bat activity more. We monitored 18 sites, including conventional, organic, and low and high-complexity landscapes. We noted more bat activity at sites with high complexity landscapes and organic practices than at sites with either low-complexity landscapes or conventional farming practices. I captured and processed bats and recorded data. I also classified insects collected from light traps. I learned how to handle bats and measure forearm length and weight, as well as how to indentify their gender. I took hair clippings and fecal samples, which yield data about the bats' diet. Their diet, in turn, gives us data about which pests they eat and therefore help control. I also learned about bats' echolocation: they have a special muscle over their ears that closes when they echolocate so that they don't burst their own eardrum. Also, some insects have evolved a special call that will disrupt bats echolocation so bats can't track it.

  12. An index method to evaluate growers’ pesticide use for identifying on-farm innovations and effective alternative pest management strategies: a case study of winegrape in Madera County, California*

    Science.gov (United States)

    Li, Wen-juan; Qin, Zhi-hao; Zhang, Ming-hua; Browde, Joe

    2011-01-01

    Winegrape is an important perennial crop in California, USA. Each year California winegrape farming consumes about 20 million kilograms of pesticides that have been a pollutant source to the fresh water systems of the state. The variation of pesticide use among winegrape growers has been significant. It has been observed that some growers have developed effective ways to reduce pesticide use, yet control pests efficiently to ensure harvest. Identification of the growers with low and high pesticide use is very helpful to extension programs that aim on reducing pesticide environmental risk. In this study, an index approach is proposed to quantitatively measure pesticide use intensity at grower level. An integrated pesticide use index is developed by taking pesticide quantity and toxicity into account. An additive formula and a multiplying formula were used to calculate the pesticide use index, i.e., PUI and PUIM. It was found that both PUI and PUIM were capable of identifying the low and high pesticide users while PUI was slightly more conservative than PUIM. All pesticides used in California winegrape farming were taken into account for calculating the indices. Madera County, one of the largest winegrape producers in California, was taken as an example to test the proposed approach. In year 2000, among the total 208 winegrape growers, 28 with PUI≤10 and 34 with 10pesticide users who were characterized with both low quantity and low toxicity of pesticide use. Most of the growers had small-sized vineyards, i.e., one field and small planted areas. Furthermore, they had very low pesticide use intensity, used only 1–2 types of pesticides (mainly fungicides), applied few pesticides (1–3 only), and emphasized the use of low toxicity compounds. Meanwhile, 19 growers with PUI>60, identified as high pesticide users, had large-sized vineyards, i.e., more fields and large planted areas. They used all types of pesticides and many compounds, which indicated that their pest

  13. Water use in California

    Science.gov (United States)

    Brandt, Justin; Sneed, Michelle; Rogers, Laurel Lynn; Metzger, Loren F.; Rewis, Diane; House, Sally F.

    2014-01-01

    As part of the USGS National Water Use Compilation, the California Water Science Center works in cooperation with local, State, and Federal agencies as well as academic and private organizations to collect and report total water withdrawals for California. The 2010 California water use data are aggregated here, in this website, for the first time. The California Water Science Center released these data ahead of the online USGS National Water Use Compilation circular report, in response to increased interest associated with current drought conditions. The national report is expected to be released late in 2014. The data on this website represents the most current California water use data available in the USGS National Water Use Compilation. It contains a section on water use in California for 2010. Water-use estimates are compiled by withdrawal source type, use category, and county. Withdrawal source types include groundwater, both fresh and saline,

  14. Soil testing for P and K has value in nutrient management for annual crops

    Directory of Open Access Journals (Sweden)

    Daniel Geisseler

    2016-08-01

    Full Text Available Adequate nutrients in forms available to plant roots are essential for sustainable crop production. Soil testing for phosphorus and potassium availability allows growers and crop advisers to determine whether a soil is likely to respond to fertilization. As yields have risen with improved management and production systems, crop nutrient demand and the removal of nutrients with harvested crops have increased. An in-depth discussion of soil tests for phosphorus and potassium and their use in California cropping systems is clearly needed. We review how these nutrients become available to plant roots, how samples are taken and test results interpreted, complementary ways to assess the adequacy of supplies and what research is needed to improve soil testing for phosphorus and potassium.

  15. BIOGAS PRODUCTION FROM CATCH CROPS

    DEFF Research Database (Denmark)

    Molinuevo-Salces, Beatriz; Larsen, Søren U.; Ahring, Birgitte Kiær

    2014-01-01

    Catch crop cultivation combined with its use for biogas production would increase renewable energy production in the form of methane, without interfering with the production of food and fodder crops. The low biomass yield of catch crops is the main limiting factor for using these crops as co......-substrate in manure-based biogas plants and the profit obtained from the sale of biogas barely compensates for the harvest costs. A new agricultural strategy to harvest catch crops together with the residual straw of the main crop was investigated to increase the biomass and thereby the methane yield per hectare...... biomass. Leaving the straw on the field until harvest of the catch crop in the autumn could benefit biogas production due to the organic matter degradation of the straw taking place on the field during the autumn months. This new agricultural strategy may be a good alternative to achieve economically...

  16. Soil microbial substrate properties and microbial community responses under irrigated organic and reduced-tillage crop and forage production systems.

    Science.gov (United States)

    Ghimire, Rajan; Norton, Jay B; Stahl, Peter D; Norton, Urszula

    2014-01-01

    Changes in soil microbiotic properties such as microbial biomass and community structure in response to alternative management systems are driven by microbial substrate quality and substrate utilization. We evaluated irrigated crop and forage production in two separate four-year experiments for differences in microbial substrate quality, microbial biomass and community structure, and microbial substrate utilization under conventional, organic, and reduced-tillage management systems. The six different management systems were imposed on fields previously under long-term, intensively tilled maize production. Soils under crop and forage production responded to conversion from monocropping to crop rotation, as well as to the three different management systems, but in different ways. Under crop production, four years of organic management resulted in the highest soil organic C (SOC) and microbial biomass concentrations, while under forage production, reduced-tillage management most effectively increased SOC and microbial biomass. There were significant increases in relative abundance of bacteria, fungi, and protozoa, with two- to 36-fold increases in biomarker phospholipid fatty acids (PLFAs). Under crop production, dissolved organic C (DOC) content was higher under organic management than under reduced-tillage and conventional management. Perennial legume crops and organic soil amendments in the organic crop rotation system apparently favored greater soil microbial substrate availability, as well as more microbial biomass compared with other management systems that had fewer legume crops in rotation and synthetic fertilizer applications. Among the forage production management systems with equivalent crop rotations, reduced-tillage management had higher microbial substrate availability and greater microbial biomass than other management systems. Combined crop rotation, tillage management, soil amendments, and legume crops in rotations considerably influenced soil

  17. Southern California Particle Center

    Data.gov (United States)

    Federal Laboratory Consortium — At the Southern California Particle Center, center researchers will investigate the underlying mechanisms that produce the health effects associated with exposure to...

  18. Reproductive traits and evolutionary divergence between Mediterranean crops and their wild relatives.

    Science.gov (United States)

    Iriondo, J M; Milla, R; Volis, S; Rubio de Casas, R

    2017-10-04

    Changes in reproductive traits associated with domestication critically determine the evolutionary divergence between crops and their wild relatives, as well as the potential of crop plants to become feral. In this review, we examine the genetic mechanisms of plant domestication and the different types of selection involved, and describe the particularities of domestication of Mediterranean field crops with regard to their reproductive traits, showing illustrative examples. We also explore gene flow patterns between Mediterranean field crops and their wild relatives, along with their ecological, evolutionary and economic implications. Domestication entails multiple selective processes, including direct selection, environmental adaptation and developmental constraints. In contrast to clonal propagation in perennials, sexual reproduction and seed propagation in annuals and biennials have led to a distinct pathway of evolution of reproductive traits. Thus, the initial domestication and further breeding of Mediterranean field crops has brought about changes in reproductive traits, such as higher mean values and variance of seed and fruit sizes, reduced fruit and seed toxicity, non-shattering seeds and loss of seed dormancy. Evolution under domestication is not a linear process, and bi-directional gene flow between wild and crop taxa is a frequent phenomenon. Thus, hybridisation and introgression have played a very important role in determining the genetics of current cultivars. In turn, gene flow from crops to wild relatives can lead to introgression of crop genes into wild populations and potentially alter the characteristics of natural communities. In conclusion, plant evolution under domestication has not only changed the reproductive biology of cultivated taxa, its effects are multifaceted and have implications beyond agriculture. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

  19. Residual soil nitrate content and profitability of five cropping systems in northwest Iowa.

    Science.gov (United States)

    De Haan, Robert L; Schuiteman, Matthew A; Vos, Ronald J

    2017-01-01

    Many communities in the Midwestern United States obtain their drinking water from shallow alluvial wells that are vulnerable to contamination by NO3-N from the surrounding agricultural landscape. The objective of this research was to assess cropping systems with the potential to produce a reasonable return for farmers while simultaneously reducing the risk of NO3-N movement into these shallow aquifers. From 2009 to 2013 we conducted a field experiment in northwest Iowa in which we evaluated five cropping systems for residual (late fall) soil NO3-N content and profitability. Soil samples were taken annually from the top 30 cm of the soil profile in June and August, and from the top 180 cm in November (late fall). The November samples were divided into 30 cm increments for analysis. Average residual NO3-N content in the top 180 cm of the soil profile following the 2010 to 2013 cropping years was 134 kg ha-1 for continuous maize (Zea mays L.) with a cereal rye (Secale cereale L.) cover crop, 18 kg ha-1 for perennial grass, 60 kg ha-1 for a three year oat (Avena sativa L.)-alfalfa (Medicago sativa L.)-maize rotation, 85 kg ha-1 for a two year oat/red clover (Trifolium pratense L.)-maize rotation, and 90 kg ha-1 for a three year soybean (Glycine max (L.) Merr.)-winter wheat (Triticum aestivum L.)-maize rotation. However, residual NO3-N in the 90 to 180 cm increment of the soil profile was not significantly higher in the oat-alfalfa-maize cropping system than the perennial grass system. For 2010 to 2013, average profit ($ ha-1 yr-1) was 531 for continuous corn, 347 for soybean-winter wheat-maize, 264 for oat-alfalfa-maize, 140 for oat/red clover-maize, and -384 (loss) for perennial grass. Considering both residual soil NO3-N and profitability data, the oat-alfalfa-maize rotation performed the best in this setting. However, given current economic pressures widespread adoption is likely to require changes in public policy.

  20. Support vector machine-based open crop model (SBOCM): Case of rice production in China.

    Science.gov (United States)

    Su, Ying-Xue; Xu, Huan; Yan, Li-Jiao

    2017-03-01

    Existing crop models produce unsatisfactory simulation results and are operationally complicated. The present study, however, demonstrated the unique advantages of statistical crop models for large-scale simulation. Using rice as the research crop, a support vector machine-based open crop model (SBOCM) was developed by integrating developmental stage and yield prediction models. Basic geographical information obtained by surface weather observation stations in China and the 1:1000000 soil database published by the Chinese Academy of Sciences were used. Based on the principle of scale compatibility of modeling data, an open reading frame was designed for the dynamic daily input of meteorological data and output of rice development and yield records. This was used to generate rice developmental stage and yield prediction models, which were integrated into the SBOCM system. The parameters, methods, error resources, and other factors were analyzed. Although not a crop physiology simulation model, the proposed SBOCM can be used for perennial simulation and one-year rice predictions within certain scale ranges. It is convenient for data acquisition, regionally applicable, parametrically simple, and effective for multi-scale factor integration. It has the potential for future integration with extensive social and economic factors to improve the prediction accuracy and practicability.

  1. Support vector machine-based open crop model (SBOCM: Case of rice production in China

    Directory of Open Access Journals (Sweden)

    Ying-xue Su

    2017-03-01

    Full Text Available Existing crop models produce unsatisfactory simulation results and are operationally complicated. The present study, however, demonstrated the unique advantages of statistical crop models for large-scale simulation. Using rice as the research crop, a support vector machine-based open crop model (SBOCM was developed by integrating developmental stage and yield prediction models. Basic geographical information obtained by surface weather observation stations in China and the 1:1000000 soil database published by the Chinese Academy of Sciences were used. Based on the principle of scale compatibility of modeling data, an open reading frame was designed for the dynamic daily input of meteorological data and output of rice development and yield records. This was used to generate rice developmental stage and yield prediction models, which were integrated into the SBOCM system. The parameters, methods, error resources, and other factors were analyzed. Although not a crop physiology simulation model, the proposed SBOCM can be used for perennial simulation and one-year rice predictions within certain scale ranges. It is convenient for data acquisition, regionally applicable, parametrically simple, and effective for multi-scale factor integration. It has the potential for future integration with extensive social and economic factors to improve the prediction accuracy and practicability.

  2. Global Simulation of Bioenergy Crop Productivity: Analytical framework and Case Study for Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Nair, S. Surendran [University of Tennessee, Knoxville (UTK); Nichols, Jeff A. {Cyber Sciences} [ORNL; Post, Wilfred M [ORNL; Wang, Dali [ORNL; Wullschleger, Stan D [ORNL; Kline, Keith L [ORNL; Wei, Yaxing [ORNL; Singh, Nagendra [ORNL; Kang, Shujiang [ORNL

    2014-01-01

    Contemporary global assessments of the deployment potential and sustainability aspects of biofuel crops lack quantitative details. This paper describes an analytical framework capable of meeting the challenges associated with global scale agro-ecosystem modeling. We designed a modeling platform for bioenergy crops, consisting of five major components: (i) standardized global natural resources and management data sets, (ii) global simulation unit and management scenarios, (iii) model calibration and validation, (iv) high-performance computing (HPC) modeling, and (v) simulation output processing and analysis. A case study with the HPC- Environmental Policy Integrated Climate model (HPC-EPIC) to simulate a perennial bioenergy crop, switchgrass (Panicum virgatum L.) and global biomass feedstock analysis on grassland demonstrates the application of this platform. The results illustrate biomass feedstock variability of switchgrass and provide insights on how the modeling platform can be expanded to better assess sustainable production criteria and other biomass crops. Feedstock potentials on global grasslands and within different countries are also shown. Future efforts involve developing databases of productivity, implementing global simulations for other bioenergy crops (e.g. miscanthus, energycane and agave), and assessing environmental impacts under various management regimes. We anticipated this platform will provide an exemplary tool and assessment data for international communities to conduct global analysis of biofuel biomass feedstocks and sustainability.

  3. LPG marketers thank the rain gods for hefty crop-drying market in '89

    Energy Technology Data Exchange (ETDEWEB)

    1990-04-01

    One of the pleasant bits of news that sprouted in many places across the country last fall concerned the increased LP-gas gallonage for crop drying. It is difficult to predict the farmers or dryers' consumption of propane in any given season. The demand for this fuel in drying operations is determined almost entirely by weather conditions, and since climate remains a perennial question mark, no one knows until the season is well under way how much moisture content the plants will exhibit. In another area, predictions can be complicated by the variations of individual farm practices as well as the evolving technology of drying equipment, including burners. This article, reports on the crop drying market as seen by various LP-gas dealers and others outside the industry.

  4. Plant water use affects competition for nitrogen: why drought favors invasive species in California.

    Science.gov (United States)

    Everard, Katherine; Seabloom, Eric W; Harpole, W Stanley; de Mazancourt, Claire

    2010-01-01

    Abstract: Classic resource competition theory typically treats resource supply rates as independent; however, nutrient supplies can be affected by plants indirectly, with important consequences for model predictions. We demonstrate this general phenomenon by using a model in which competition for nitrogen is mediated by soil moisture, with competitive outcomes including coexistence and multiple stable states as well as competitive exclusion. In the model, soil moisture regulates nitrogen availability through soil moisture dependence of microbial processes, leaching, and plant uptake. By affecting water availability, plants also indirectly affect nitrogen availability and may therefore alter the competitive outcome. Exotic annual species from the Mediterranean have displaced much of the native perennial grasses in California. Nitrogen and water have been shown to be potentially limiting in this system. We parameterize the model for a Californian grassland and show that soil moisture-mediated competition for nitrogen can explain the annual species' dominance in drier areas, with coexistence expected in wetter regions. These results are concordant with larger biogeographic patterns of grassland invasion in the Pacific states of the United States, in which annual grasses have invaded most of the hot, dry grasslands in California but perennial grasses dominate the moister prairies of northern California, Oregon, and Washington.

  5. 75 FR 65423 - Crop Assistance Program

    Science.gov (United States)

    2010-10-25

    ..., for a producer ] in a disaster county as of October 22, 2010. Subsequent crops, replacement crops.... Replacement crop means the planting or approved prevented planting of any crop for harvest following the... cotton, soybeans, or sweet potatoes not in a recognized double- cropping sequence. Replacement crops are...

  6. AquaCrop-OS: A tool for resilient management of land and water resources in agriculture

    Science.gov (United States)

    Foster, Timothy; Brozovic, Nicholas; Butler, Adrian P.; Neale, Christopher M. U.; Raes, Dirk; Steduto, Pasquale; Fereres, Elias; Hsiao, Theodore C.

    2017-04-01

    Water managers, researchers, and other decision makers worldwide are faced with the challenge of increasing food production under population growth, drought, and rising water scarcity. Crop simulation models are valuable tools in this effort, and, importantly, provide a means of quantifying rapidly crop yield response to water, climate, and field management practices. Here, we introduce a new open-source crop modelling tool called AquaCrop-OS (Foster et al., 2017), which extends the functionality of the globally used FAO AquaCrop model. Through case studies focused on groundwater-fed irrigation in the High Plains and Central Valley of California in the United States, we demonstrate how AquaCrop-OS can be used to understand the local biophysical, behavioural, and institutional drivers of water risks in agricultural production. Furthermore, we also illustrate how AquaCrop-OS can be combined effectively with hydrologic and economic models to support drought risk mitigation and decision-making around water resource management at a range of spatial and temporal scales, and highlight future plans for model development and training. T. Foster, et al. (2017) AquaCrop-OS: An open source version of FAO's crop water productivity model. Agricultural Water Management. 181: 18-22. http://dx.doi.org/10.1016/j.agwat.2016.11.015.

  7. GEOGLAM Crop Monitor Assessment Tool: Developing Monthly Crop Condition Assessments

    Science.gov (United States)

    McGaughey, K.; Becker Reshef, I.; Barker, B.; Humber, M. L.; Nordling, J.; Justice, C. O.; Deshayes, M.

    2014-12-01

    The Group on Earth Observations (GEO) developed the Global Agricultural Monitoring initiative (GEOGLAM) to improve existing agricultural information through a network of international partnerships, data sharing, and operational research. This presentation will discuss the Crop Monitor component of GEOGLAM, which provides the Agricultural Market Information System (AMIS) with an international, multi-source, and transparent consensus assessment of crop growing conditions, status, and agro-climatic conditions likely to impact global production. This activity covers the four primary crop types (wheat, maize, rice, and soybean) within the main agricultural producing regions of the AMIS countries. These assessments have been produced operationally since September 2013 and are published in the AMIS Market Monitor Bulletin. The Crop Monitor reports provide cartographic and textual summaries of crop conditions as of the 28th of each month, according to crop type. This presentation will focus on the building of international networks, data collection, and data dissemination.

  8. Witch Wildland Fire, California

    Science.gov (United States)

    2007-01-01

    The October wildfires that plagued southern California were some of the worst on record. One of these, the Witch Wildland fire, burned 198,000 acres north of San Diego, destroying 1125 homes, commercial structures, and outbuildings. Over 3,000 firefighters finally contained the fire two weeks after it started on October 21. Now begins the huge task of planning and implementing mitigation measures to replant and reseed the burned areas. This ASTER image depicts the area after the fire, on November 6; vegetation is green, burned areas are dark red, and urban areas are blue. On the burn severity index image, calculated using infrared and visible bands, red areas are the most severely burned, followed by green and blue. This information can help the US Forest Service to plan post-fire activities. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra spacecraft. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The

  9. Mapping of QTL for resistance to powdery mildew and resistance gene analogues in perennial ryegrass

    DEFF Research Database (Denmark)

    Schejbel, B; Jensen, L B; Asp, T

    2008-01-01

    -50 and the heritability was 71.7%. In total, two QTL for powdery mildew resistance were identified, and mapped to linkage groups (LG) LG3 and LG7. Individually, these QTL explained between 7.5% and 22.1% of the total phenotypic variation. Six RGA and three laccases were mapped to LG2, LG3, LG4, LG5 and LG7, however......The objective of this study was to map resistance gene analogues (RGA) and quantitative trait loci (QTL) for powdery mildew resistance in perennial ryegrass (Lolium perenne L.). The mapping population consisted of 184 F2 genotypes produced from a cross between one genotype of a synthetic perennial...

  10. A proteomics sample preparation method for mature, recalcitrant leaves of perennial plants.

    Science.gov (United States)

    Gang, Deng; Xinyue, Zhong; Na, Zhang; Chengying, Lao; Bo, Wang; Dingxiang, Peng; Lijun, Liu

    2014-01-01

    Sample preparation is key to the success of proteomics studies. In the present study, two sample preparation methods were tested for their suitability on the mature, recalcitrant leaves of six representative perennial plants (grape, plum, pear, peach, orange, and ramie). An improved sample preparation method was obtained: Tris and Triton X-100 were added together instead of CHAPS to the lysis buffer, and a 20% TCA-water solution and 100% precooled acetone were added after the protein extraction for the further purification of protein. This method effectively eliminates nonprotein impurities and obtains a clear two-dimensional gel electrophoresis array. The method facilitates the separation of high-molecular-weight proteins and increases the resolution of low-abundance proteins. This method provides a widely applicable and economically feasible technology for the proteomic study of the mature, recalcitrant leaves of perennial plants.

  11. Development of a Molecular Breeding Strategy for the Integration of Transgenic Traits in Outcrossing Perennial Grasses

    Directory of Open Access Journals (Sweden)

    Pieter E. Badenhorst

    2016-11-01

    Full Text Available Molecular breeding tools, such as genetic modification, provide forage plant breeders with the opportunity to incorporate high value traits into breeding programs which, in some cases, would not be available using any other methodology. Despite the potential impact of these traits, little work has been published that seeks to optimize the strategies for transgenic breeding or incorporate transgenic breeding with other modern genomics-assisted breeding strategies. As the number of new genomics assisted breeding tools become available it is also likely that multiple tools may be used within the one breeding program. In this paper we propose a strategy for breeding genetically-modified forages using perennial ryegrass as an example and demonstrate how this strategy may be linked with other technologies, such as genomic selection. Whilst the model used is perennial ryegrass the principles outlined are valid for those designing breeding strategies for other outcrossing forage species.

  12. A proteomics sample preparation method for mature, recalcitrant leaves of perennial plants.

    Directory of Open Access Journals (Sweden)

    Deng Gang

    Full Text Available Sample preparation is key to the success of proteomics studies. In the present study, two sample preparation methods were tested for their suitability on the mature, recalcitrant leaves of six representative perennial plants (grape, plum, pear, peach, orange, and ramie. An improved sample preparation method was obtained: Tris and Triton X-100 were added together instead of CHAPS to the lysis buffer, and a 20% TCA-water solution and 100% precooled acetone were added after the protein extraction for the further purification of protein. This method effectively eliminates nonprotein impurities and obtains a clear two-dimensional gel electrophoresis array. The method facilitates the separation of high-molecular-weight proteins and increases the resolution of low-abundance proteins. This method provides a widely applicable and economically feasible technology for the proteomic study of the mature, recalcitrant leaves of perennial plants.

  13. [Clinical and laboratory features of 100 patients with perennial allergic rhinitis].

    Science.gov (United States)

    Segura Méndez, N H; Martínez Diéguez, H; Cisneros González, N

    1993-01-01

    100 patient records were studied with a clinical diagnosis of perennial allergic rhinitis; they were 66 women and 34 men, with a range of 28.6 years old. The cutaneous tests were positive to pollens in 78% of the cases, fungus 39%, inhalables 39%, Dermatophagoides 19% and bacterial 7%. In the nasal mucous culture the following germs were isolated: S epidermidis 49%, S aureus 25%, Neisseria sp 15%, Corynebacterium 2%, P mirabilis 1% and E coli 1%. The nasal cytology was positive in 25% of the cases for the presence of eosinophils, and was negative in 75%. In only 27% of the patients eosinophil was found in the peripheric blood. The results are commented and the utility of the cultivation of nasal mucous and of the cytology of nasal mucous in patients with perennial allergic rhinitis is discussed.

  14. EVALUATION OF PERFORMANCE PARAMETERS FOR TRACE ELEMENTS ANALYSIS IN PERENNIAL PLANTS

    Directory of Open Access Journals (Sweden)

    ŞENILĂ MARIN

    2011-12-01

    Full Text Available The aim of this paper is to present the validation of inductively coupled plasma optical emission spectrometry (ICP-OES method used for metals determination from several perennial plant samples. The suitability of two digestion procedures using wet digestion with mineral acids mixture on hot plate and microwave digestion was investigated to determine As, Cd, Cu, Fe, Mn, Pb and Zn in plants samples. The LOD of the seven analysed elements in solid samples varied between 0.20µg g-1 for Mn and 0.55µg g-1 for Pb. The found values for metals determined by ICP-OES in a vegetable certified reference material digested using the two procedures were compared with the certified values and good agreements between these values were obtained. The proposed method indicated satisfactory recovery, detection limits and standard deviations for trace metal determination in perennial plants samples.

  15. Reform's stunted crop

    OpenAIRE

    Orden, David

    2002-01-01

    Congress is on the verge of finalizing a new long-term farm bill to replace legislation passed in 1996. The earlier legislation, when it was enacted, received attention for ist potential to end farm subsidies as they had been known. If Congress had adhered to the 1996 law, both the level and year-to-year variability of previous farm support outlays would have been reduced. Instead, when a three-year run of high crop prices collapsed in 1998, lawmakers began appropriating extra support payment...

  16. Fructan storage and regeneration of perennial weeds: Cirsium arvense (L.) Scop and Tussilago farfara (L.)

    OpenAIRE

    Nkurunziza, Libère; Streibig, Jens Carl

    2011-01-01

    Carbohydrate storage in underground organs of perennial weeds will increase because of the increasing temperatures and CO2 concentrations that increase photosynthesis. The objective of this study was to understand the effects of temperature and shoot age on the storage of fructan, the main carbohydrate storage, and the depletion associated with regeneration during the early growth. We subjected juvenile and mature plants of Canada thistle and Coltsfoot to different temperatures, in growth cha...

  17. Dormancy in reproductive vegetative buds in creeping perennials dominating the agricultural weed flora in Scandinavia

    OpenAIRE

    Liew, Josefine

    2013-01-01

    Dormancy, which is the inability to initiate normal growth under otherwise favourable conditions, is an adaptation to escape sprouting prior to seasonal cold temperatures and/or drought in areas where winters are harsh or summers dry. Dormancy in woody perennials of northern temperate areas is, in general, induced by photoperiodic and/or temperature changes, and released after prolonged exposure to chilling. Besides being species specific, northern ecotypes are usually more sensitive to induc...

  18. De novo assembly of the perennial ryegrass transcriptome using an RNA-Seq strategy.

    Directory of Open Access Journals (Sweden)

    Jacqueline D Farrell

    Full Text Available Perennial ryegrass is a highly heterozygous outbreeding grass species used for turf and forage production. Heterozygosity can affect de-Bruijn graph assembly making de novo transcriptome assembly of species such as perennial ryegrass challenging. Creating a reference transcriptome from a homozygous perennial ryegrass genotype can circumvent the challenge of heterozygosity. The goals of this study were to perform RNA-sequencing on multiple tissues from a highly inbred genotype to develop a reference transcriptome. This was complemented with RNA-sequencing of a highly heterozygous genotype for SNP calling.De novo transcriptome assembly of the inbred genotype created 185,833 transcripts with an average length of 830 base pairs. Within the inbred reference transcriptome 78,560 predicted open reading frames were found of which 24,434 were predicted as complete. Functional annotation found 50,890 transcripts with a BLASTp hit from the Swiss-Prot non-redundant database, 58,941 transcripts with a Pfam protein domain and 1,151 transcripts encoding putative secreted peptides. To evaluate the reference transcriptome we targeted the high-affinity K+ transporter gene family and found multiple orthologs. Using the longest unique open reading frames as the reference sequence, 64,242 single nucleotide polymorphisms were found. One thousand sixty one open reading frames from the inbred genotype contained heterozygous sites, confirming the high degree of homozygosity.Our study has developed an annotated, comprehensive transcriptome reference for perennial ryegrass that can aid in determining genetic variation, expression analysis, genome annotation, and gene mapping.

  19. The role of changing climate in driving the shift from perennial grasses to annual succulents in a Mediterranean saltmarsh

    NARCIS (Netherlands)

    Strain, E.M.A.; van Belzen, J.; Comandini, P.; Wong, J.; Bouma, T.J.; Airoldi, L.

    2017-01-01

    Changing climate threatens the structure and function of saltmarshes, which are often severely degraded by other human perturbations. Along the Mediterranean coastline, increasing temperature and decreasing rainfall have been hypothesised to trigger habitat shifts from perennial grasses to annual

  20. Optimal Regulation of the Balance between Productivity and Overwintering of Perennial Grasses in a Warmer Climate

    Directory of Open Access Journals (Sweden)

    Åshild Ergon

    2017-02-01

    Full Text Available Seasonal growth patterns of perennial plants are linked to patterns of acclimation and de-acclimation to seasonal stresses. The timing of cold acclimation (development of freezing resistance and leaf growth cessation in autumn, and the timing of de-acclimation and leaf regrowth in spring, is regulated by seasonal cues in the environment, mainly temperature and light factors. Warming will lead to new combinations of these cues in autumn and spring. Extended thermal growing seasons offer a possibility for obtaining increased yields of perennial grasses at high latitudes. Increased productivity in the autumn may not be possible in all high latitude regions due to the need for light during cold acclimation and the need for accumulating a carbohydrate storage prior to winter. There is more potential for increased yields in spring due to the availability of light, but higher probability of freezing events in earlier springs would necessitate a delay of de-acclimation, or an ability to rapidly re-acclimate. In order to optimize the balance between productivity and overwintering in the future, the regulation of growth and acclimation processes may have to be modified. Here, the current knowledge on the coordinated regulation of growth and freezing resistance in perennial grasses is reviewed.

  1. Fast-cycling unit of root turnover in perennial herbaceous plants in a cold temperate ecosystem

    Science.gov (United States)

    Sun, Kai; Luke McCormack, M.; Li, Le; Ma, Zeqing; Guo, Dali

    2016-01-01

    Roots of perennial plants have both persistent portion and fast-cycling units represented by different levels of branching. In woody species, the distal nonwoody branch orders as a unit are born and die together relatively rapidly (within 1-2 years). However, whether the fast-cycling units also exist in perennial herbs is unknown. We monitored root demography of seven perennial herbs over two years in a cold temperate ecosystem and we classified the largest roots on the root collar or rhizome as basal roots, and associated finer laterals as secondary, tertiary and quaternary roots. Parallel to woody plants in which distal root orders form a fast-cycling module, basal root and its finer laterals also represent a fast-cycling module in herbaceous plants. Within this module, basal roots had a lifespan of 0.5-2 years and represented 62-87% of total root biomass, thus dominating annual root turnover (60%-81% of the total). Moreover, root traits including root length, tissue density, and biomass were useful predictors of root lifespan. We conclude that both herbaceous and woody plants have fast-cycling modular units and future studies identifying the fast-cycling module across plant species should allow better understanding of how root construction and turnover are linked to whole-plant strategies.

  2. Classification of ephemeral, intermittent, and perennial stream reaches using a TOPMODEL-based approach

    Science.gov (United States)

    Williamson, Tanja N.; Agouridis, Carmen T.; Barton, Christopher D.; Villines, Jonathan A.; Lant, Jeremiah G.

    2015-01-01

    Whether a waterway is temporary or permanent influences regulatory protection guidelines, however, classification can be subjective due to a combination of factors, including time of year, antecedent moisture conditions, and previous experience of the field investigator. Our objective was to develop a standardized protocol using publically available spatial information to classify ephemeral, intermittent, and perennial streams. Our hypothesis was that field observations of flow along the stream channel could be compared to results from a hydrologic model, providing an objective method of how these stream reaches can be identified. Flow-state sensors were placed at ephemeral, intermittent, and perennial stream reaches from May to December 2011 in the Appalachian coal basin of eastern Kentucky. This observed flow record was then used to calibrate the simulated saturation deficit in each channel reach based on the topographic wetness index used by TOPMODEL. Saturation deficit values were categorized as flow or no-flow days, and the simulated record of streamflow was compared to the observed record. The hydrologic model was more accurate for simulating flow during the spring and fall seasons. However, the model effectively identified stream reaches as intermittent and perennial in each of the two basins.

  3. Population structure, genetic variation and linkage disequilibrium in perennial ryegrass populations divergently selected for freezing tolerance

    Directory of Open Access Journals (Sweden)

    Mallikarjuna Rao eKovi

    2015-11-01

    Full Text Available Low temperature is one of the abiotic stresses seriously affecting the growth of perennial ryegrass (Lolium perenne L. Understanding the genetic control of freezing tolerance would aid in the development of cultivars of perennial ryegrass with improved adaptation to frost. A total number of 80 individuals (24 of High frost [HF]; 29 of Low frost [LF] and 27 of Unselected [US] from the second generation of the two divergently selected populations and an unselected control population were genotyped using 278 genome-wide SNPs derived from Lolium perenne L. transcriptome sequence. Our studies showed that the HF and LF populations are very divergent after selection for freezing tolerance, whereas the HF and US populations are more similar. Linkage disequilibrium (LD decay varied across the seven chromosomes and the conspicuous pattern of LD between the HF and LF population confirmed their divergence in freezing tolerance. Furthermore, two Fst outlier methods; finite island model (fdist by LOSITAN and hierarchical structure model using ARLEQUIN detected six loci under directional selection. These outlier loci are most probably linked to genes involved in freezing tolerance, cold adaptation and abiotic stress and might be the potential marker resources for breeding perennial ryegrass cultivars with improved freezing tolerance.

  4. Mechanisms of glyphosate resistance in two perennial ryegrass (Lolium perenne) populations.

    Science.gov (United States)

    Ghanizadeh, Hossein; Harrington, Kerry C; James, Trevor K; Woolley, David J; Ellison, Nicholas W

    2015-12-01

    Perennial ryegrass (Lolium perenne) has developed resistance to glyphosate within New Zealand vineyards following many years of herbicide application. The objectives of this work were to confirm resistance within two populations obtained from affected vineyards, and to determine the mechanism of resistance to glyphosate. Population O was confirmed to have a 25-fold resistance to glyphosate, whereas population J had a sevenfold resistance. Results of genotyping assays demonstrated a single nucleotide substitution at codon 106 of 5-enolpyruvylshikimate-3-phosphate synthase in population O but not population J. Glyphosate-resistant and glyphosate-susceptible populations did not differ in glyphosate absorption. However, in both resistant populations, much more of the absorbed (14) C-glyphosate remained in the treated leaf than occurred in the susceptible population. Significantly more glyphosate was found in the pseudostem region of susceptible plants compared with resistant plants. Both target-site and non-target-site mechanisms of glyphosate resistance were found in the perennial ryegrass population with 25-fold resistance, whereas only the non-target-site mechanism of resistance was found in the population with sevenfold resistance. This is the first study of the mechanism of glyphosate resistance in perennial ryegrass. © 2014 Society of Chemical Industry.

  5. Fast-cycling unit of root turnover in perennial herbaceous plants in a cold temperate ecosystem.

    Science.gov (United States)

    Sun, Kai; McCormack, M Luke; Li, Le; Ma, Zeqing; Guo, Dali

    2016-01-21

    Roots of perennial plants have both persistent portion and fast-cycling units represented by different levels of branching. In woody species, the distal nonwoody branch orders as a unit are born and die together relatively rapidly (within 1-2 years). However, whether the fast-cycling units also exist in perennial herbs is unknown. We monitored root demography of seven perennial herbs over two years in a cold temperate ecosystem and we classified the largest roots on the root collar or rhizome as basal roots, and associated finer laterals as secondary, tertiary and quaternary roots. Parallel to woody plants in which distal root orders form a fast-cycling module, basal root and its finer laterals also represent a fast-cycling module in herbaceous plants. Within this module, basal roots had a lifespan of 0.5-2 years and represented 62-87% of total root biomass, thus dominating annual root turnover (60%-81% of the total). Moreover, root traits including root length, tissue density, and biomass were useful predictors of root lifespan. We conclude that both herbaceous and woody plants have fast-cycling modular units and future studies identifying the fast-cycling module across plant species should allow better understanding of how root construction and turnover are linked to whole-plant strategies.

  6. [Frequency of sensitization to aeroallergens in patients with seasonal and perennial allergic conjunctivitis].

    Science.gov (United States)

    Cortés-Morales, Guillermina; Velasco-Medina, Andrea Aida; Arroyo-Cruz, Mariana Esther; Velázquez-Sámano, Guillermo

    2014-01-01

    Allergic conjunctivitis is an inflammatory disease which involves the conjunctiva, its physiopathology is a type I hypersensitivity (IgE mediated). It is related to the sensitization to indoors and outdoors aeroallergens. Clinically it is classified as seasonal or perennial. It presents as ocular pruritus, conjunctival hyperemia, epiphora and photophobia. To determine the frequency of sensitization to aeroallergens in patients with allergic conjunctivitis, seasonal and perennial, who attend the Allergy and Clinical Immunology Department at Mexican General Hospital Dr. Eduardo Liceaga. A transversal and descriptive study was made in patients with seasonal and perennial allergic conjunctivitis. After informed consent, we obtained a complete clinical evaluation, laboratory studies and skin tests for aeroallergens. We determined the frequency of sensitization to those aeroallergens. We found sensitization most frequently to pollens such as Quercus, Alnus and Fraxinus, followed by Dermatophagoides spp. We had predominantly female patients of the second and fourth decades of life. Allergic conjunctivitis is a pathology frequently associated with allergic rhinitis. The most frequently involved allergens in this study were pollens and house dust mite.

  7. Spain: Europe's California.

    Science.gov (United States)

    Wilvert, Calvin

    1994-01-01

    Contends that, as Spain integrates into the European Economic Community, it is considered to be Europe's California. Asserts that making regional comparisons between California and Spain can be an effective teaching method. Provides comparisons in such areas as agriculture and tourism. (CFR)

  8. California-Baja California border master plan - plan maestro fronterizo California-Baja California : executive summary.

    Science.gov (United States)

    2008-09-01

    Crossborder travel at the six land ports of entry (POEs) in the California-Baja California region has grown : significantly over the years. The San Diego County-Tijuana/Tecate region is home to the San Ysidro- : Puerta Mxico, the Otay Mesa-Mesa de ...

  9. California-Baja California border master plan - plan maestro fronterizo California-Baja California.

    Science.gov (United States)

    2008-09-01

    Crossborder travel at the six land ports of entry (POEs) in the California-Baja California region has grown : significantly over the years. The San Diego County-Tijuana/Tecate region is home to the San Ysidro- : Puerta Mxico, the Otay Mesa-Mesa de ...

  10. California's Reference Crisis.

    Science.gov (United States)

    Childers, Thomas A.

    1994-01-01

    Social and economic issues affecting the vitality of public libraries in California are discussed. A 1993 study by the California State Library identified diminishing reference skills and reference collections, reduced funding which impacted staffing, increased demand, technology change, and language/culture issues as contributing factors to…

  11. Introduction of Alley Cropping

    Directory of Open Access Journals (Sweden)

    Sugeng Parmadi

    2004-01-01

    Full Text Available One of the efforts to preserve the sources of vegetarian, soil, and water is to rehabilitate the land and soil conservation. The aim of this rehabilitation is increasing and maintaining the produtivity of the land, so it can be preserved and used optimally. Therefore, it is necessary to a  develop a variety of good soil conservation, such as vegetative method and civil engineering. To find an appropriate technology, so it is necessary to develop some alternatives of soil conservation technique that are mainly implemented at dry land with its slope of more than 15% in the upstream area of discharge. One of the most suitable soil conservation technique today is Alley Cropping. Based on the research (trial and error in some areas, Alley Cropping could really provide a positive result in terms of erotion controlling and running off and maintain the land productivity. In addition, the technique is more easly operated and spends a cheaper cost than making a bench terrace.

  12. Environmental Assessment: 13th Street Bridge Emergency Repair and Retrofit Vandenberg Air Force Base California

    Science.gov (United States)

    2003-06-23

    ursinus), nightshade (Solanum sp.), California figwort (Scrophularia cal{fiJrnica), and mugwort ( Artemisia douglasiana). Coyote brush...is readily available. Coastal sage scrub is a diverse vegetation type dominated by the shrub California sagebrush ( Artemisia cal{fiJrnica). In...row crops planted on the fertile valley bottoms. In 1933, the Marshall family moved to the Olivera adobe, and expanded and modernized the building. A

  13. Environmental Assessment for Landfill Drainage Improvements Vandenberg Air Force Base, California

    Science.gov (United States)

    2003-04-07

    Stachys bullata), mugwort ( Artemisia douglasiana), gooseberry (Ribes divaricatum), California rose (Rosa califomica), wax myrtle (Myrica califomica...compete with the more profitable sugar beets and other row crops planted on the fertile valley bottoms. In 1933, the Marshall family moved to the...Drainage Improvements Vandenberg Air Force Base, California PageA-5 I I I I I I i I I I I ( Artemisia califomica). In disturbed or more

  14. Diaprepes root weevil, a new California pest, will raise costs for pest control and trigger quarantines

    OpenAIRE

    Jetter, Karen M.; Godfrey, Kris

    2009-01-01

    This study presents an economic analysis of cost increases for citrus, avocado and nursery producers should the Diaprepes root weevil become established in California. First identified in Southern California in 2005, Diaprepres would mainly affect orange, grapefruit, lemon and avocado crops. The primary impacts would be increased production costs for pest treatments and increased harvesting costs to conform to quarantine regulations, in particular to ship ornamental plants out of infested reg...

  15. A Data-driven Approach to Integrate Crop Rotation Agronomic Practices in a Global Gridded Land-use Forcing Dataset

    Science.gov (United States)

    Sahajpal, R.; Hurtt, G. C.; Chini, L. P.; Frolking, S. E.; Izaurralde, R. C.

    2016-12-01

    Agro-ecosystems are the dominant land-use type on Earth, covering more than a third of ice-free land surface. Agricultural practices have influenced the Earth's climate system by significantly altering the biogeophysical and biogeochemical properties from hyper-local to global scales. While past work has focused largely on characterizing the effects of net land cover changes, the magnitude and nature of gross transitions and agricultural management practices on climate remains highly uncertain. To address this issue, a new set of global gridded land-use forcing datasets (LUH2) have been developed in a standard format required by climate models for CMIP6. For the first time, this dataset includes information on key agricultural management practices including crop rotations. Crop rotations describe the practice of growing crops on the same land in sequential seasons and are essential to agronomic management as they influence key ecosystem services such as crop yields, water quality, carbon and nutrient cycling, pest and disease control. Here, we present a data-driven approach to infer crop rotations based on crop specific land cover data, derived from moderate resolution satellite imagery and created at an annual time-step for the continental United States. Our approach compresses the more than 100,000 unique crop rotations prevalent in the United States from 2013 - 2015 to about 200 representative crop rotations that account for nearly 80% of the spatio-temporal variability. Further simplification is achieved by mapping individual crops to crop functional types, which identify crops based on their photosynthetic pathways (C3/C4), life strategy (annual/perennial) and whether they are N-fixing or not. The resulting matrix of annual transitions between crop functional types averages 41,000 km2/yr for rotations between C3 and C4 annual crops, and 140,000 km2/yr between C3 N-fixing and C4 annual crops. The crop rotation matrix is combined with information on other land

  16. A revised logistic regression equation and an automated procedure for mapping the probability of a stream flowing perennially in Massachusetts

    Science.gov (United States)

    Bent, Gardner C.; Steeves, Peter A.

    2006-01-01

    A revised logistic regression equation and an automated procedure were developed for mapping the probability of a stream flowing perennially in Massachusetts. The equation provides city and town conservation commissions and the Massachusetts Department of Environmental Protection a method for assessing whether streams are intermittent or perennial at a specific site in Massachusetts by estimating the probability of a stream flowing perennially at that site. This information could assist the environmental agencies who administer the Commonwealth of Massachusetts Rivers Protection Act of 1996, which establishes a 200-foot-wide protected riverfront area extending from the mean annual high-water line along each side of a perennial stream, with exceptions for some urban areas. The equation was developed by relating the observed intermittent or perennial status of a stream site to selected basin characteristics of naturally flowing streams (defined as having no regulation by dams, surface-water withdrawals, ground-water withdrawals, diversion, wastewater discharge, and so forth) in Massachusetts. This revised equation differs from the equation developed in a previous U.S. Geological Survey study in that it is solely based on visual observations of the intermittent or perennial status of stream sites across Massachusetts and on the evaluation of several additional basin and land-use characteristics as potential explanatory variables in the logistic regression analysis. The revised equation estimated more accurately the intermittent or perennial status of the observed stream sites than the equation from the previous study. Stream sites used in the analysis were identified as intermittent or perennial based on visual observation during low-flow periods from late July through early September 2001. The database of intermittent and perennial streams included a total of 351 naturally flowing (no regulation) sites, of which 85 were observed to be intermittent and 266 perennial

  17. Modeling the yield potential of dryland canola under current and future climates in California

    Science.gov (United States)

    George, N.; Kaffka, S.; Beeck, C.; Bucaram, S.; Zhang, J.

    2012-12-01

    Models predict that the climate of California will become hotter, drier and more variable under future climate change scenarios. This will lead to both increased irrigation demand and reduced irrigation water availability. In addition, it is predicted that most common Californian crops will suffer a concomitant decline in productivity. To remain productive and economically viable, future agricultural systems will need to have greater water use efficiency, tolerance of high temperatures, and tolerance of more erratic temperature and rainfall patterns. Canola (Brassica napus) is the third most important oilseed globally, supporting large and well-established agricultural industries in Canada, Europe and Australia. It is an agronomically useful and economically valuable crop, with multiple end markets, that can be grown in California as a dryland winter rotation with little to no irrigation demand. This gives canola great potential as a new crop for Californian farmers both now and as the climate changes. Given practical and financial limitations it is not always possible to immediately or widely evaluate a crop in a new region. Crop production models are therefore valuable tools for assessing the potential of new crops, better targeting further field research, and refining research questions. APSIM is a modular modeling framework developed by the Agricultural Production Systems Research Unit in Australia, it combines biophysical and management modules to simulate cropping systems. This study was undertaken to examine the yield potential of Australian canola varieties having different water requirements and maturity classes in California using APSIM. The objective of the work was to identify the agricultural regions of California most ideally suited to the production of Australian cultivars of canola and to simulate the production of canola in these regions to estimate yield-potential. This will establish whether the introduction and in-field evaluation of better

  18. Plant senescence and crop productivity

    DEFF Research Database (Denmark)

    Gregersen, Per L.; Culetic, Andrea; Boschian, Luca

    2013-01-01

    Senescence is a developmental process which in annual crop plants overlaps with the reproductive phase. Senescence might reduce crop yield when it is induced prematurely under adverse environmental conditions. This review covers the role of senescence for the productivity of crop plants...... plants, the expression of the IPT gene under control of senescence-associated promoters has been the most successful. The promoters employed for senescence-regulated expression contain cis-elements for binding of WRKY transcription factors and factors controlled by abscisic acid. In most crops...

  19. Diagnostics, taxonomy, nomenclature and distribution of perennial Sesuvium (Aizoaceae) in Africa

    Science.gov (United States)

    Sukhorukov, Alexander P.; Nilova, Maya V.; Erst, Andrey S.; Kushunina, Maria; Baider, Cláudia; Verloove, Filip; Salas-Pascual, Marcos; Belyaeva, Irina V.; Krinitsina, Anastasiya A.; Bruyns, Peter V.; Klak, Cornelia

    2018-01-01

    Abstract The taxonomy of perennial Sesuvium species in Africa has been poorly investigated until now. Previously five perennial species of Sesuvium were recognised in Africa (S. congense, S. crithmoides, S. mesembryanthemoides, S. portulacastrum, and S. sesuvioides). Based on the differing number of stamens, S. ayresii is accepted here as being distinct from S. portulacastrum. Field observations in Angola also led the authors to conclude that S. crystallinum and S. mesembryanthemoides are conspecific with S. crithmoides. A new subspecies, Sesuvium portulacastrum subsp. persoonii, is described from West Africa (Cape Verde, Gambia, Guinea-Bissau, Mauritania, Senegal). The molecular phylogeny indicates the position of S. portulacastrum subsp. persoonii within the “American lineage” as a part of the Sesuvium portulacastrum complex which needs further studies. A diagnostic key and taxonomic notes are provided for the six perennial species of Sesuvium found in Africa and recognised by the authors (S. ayresii, S. congense, S. crithmoides, S. portulacastrum subsp. portulacastrum, S. portulacastrum subsp. persoonii, S. verrucosum and the facultatively short-lived S. sesuvioides). The distribution of S. crithmoides, previously considered to be endemic to Angola, is now confirmed for the seashores of Republic of Congo and DR Congo. The American species S. verrucosum is reported for the first time for Africa (the Macaronesian islands: Cape Verde and the Canaries). It is locally naturalised in Gran Canaria, being a potentially invasive species. These findings as well as new records of S. verrucosum from Asia and the Pacific Islands confirm its proneness to transcontinental introduction. Lectotypes of S. brevifolium, S. crithmoides, S. crystallinum and S. mesembryanthemoides are selected. The seed micromorphology and anatomy of the perennial African species is studied. Compared to the seeds of some annual African Sesuvium investigated earlier, those of perennial species are

  20. Stable Food Crops Turning Into Commercial Crops: Case Studies Of ...

    African Journals Online (AJOL)

    Stable Food Crops Turning Into Commercial Crops: Case Studies Of Teff, Wheat And Rice In Ethiopia. ... attention is needed to female headed households in the process of commercial transformation of subsistence agriculture. The development and institutionalization of marketing extension warrants due consideration.

  1. Stable Food Crops Turning Into Commercial Crops: Case studies of ...

    African Journals Online (AJOL)

    RahelYilma

    Sustainable food security and welfare cannot be achieved through subsistence agriculture (Pingali, 1997). ... Hence, in this study,. 3 Teff is a grass-like fine seeded staple food crop grown in Ethiopia. 4 APA is the .... the suitability of the agro-ecology for the crop, while distance to milling service affects cost of consumption.

  2. 605 Salad crops: Root, bulb, and tuber Crops

    Science.gov (United States)

    Root and tuber crops (potato, cassava, sweet potato, and yams) comprise 4 of the 10 major food staples of the world and serve as a major source of energy for the poor of developing nations. Minimal strain placed on agro ecosystems by root and tuber crops highlight their welcomed contribution to the ...

  3. SEASONALITY OF ANNUAL PLANT ESTABLISHMENT INFLUENCES THE INTERACTIONBETWEEN THE NON-NATIVE ANNUAL GRASS BROMUS MADRITENSIS SSP. RUBENS AND MOJAVE DESERT PERENNIALS

    Energy Technology Data Exchange (ETDEWEB)

    L A. DEFALCO; G. C. FERNANDEZ; R. S. NOWAK

    2004-01-01

    Competition between native and non-native species can change the composition and structure of plant communities, but in deserts the timing of non-native plant establishment can modulate their impacts to native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individuals of three native perennials--Larrea iridentata, Achnatherum hymenoides, and Pleuraphis rigida--in either winter or spring. Additional plots were prepared for the Same perennial species and seasons, but with a mixture of native annual species. Relative growth rates of perennial shoots (RGRs) declined with increasing Bromus biomass when Bromus that was established in winter had 2-3 mo of growth and high water use before perennial growth began. However, this high water use did not significantly reduce water potentials for the perennials, suggesting Bromus that established earlier depleted other soil resources, such as N, otherwise used by perennial plants. Spring-established Bromus had low biomass even at higher densities and did not effectively reduce RGRs, resulting in an overall lower impact to perennials than when Bromus was established in winter. Similarly, growth and reproduction of perennials with mixed annuals as neighbors did not differ from those with Bromus neighbors of equivalent biomass, but densities of these annuals did not support the high biomass necessary to reduce perennial growth. Thus, impacts of native Mojave Desert annuals to perennials are expected to be lower than those of Bromus because seed dormancy and narrow requirements for seedling survivorship produce densities and biomass lower than those achieved by Bromus. In comparing the effects of Bromus among perennial species, the impact of increased Bromus biomass on RGR was lower for Larrea than for the two perennial grasses, probably because Lurrea maintains low growth rates throughout the year, even after Bromus has completed its life cycle. This contrasts

  4. Biosolarization in garlic crop

    Science.gov (United States)

    Fabeiro, Concepcion; Andres, Manuela; Wic, Consuelo

    2014-05-01

    One of the most important limitations of garlic cultivation is the presence of various soil pathogens. Fusarium proliferatum and Sclerotinium cepivorum and nematode Ditilenchus dipsaci cause such problems that prevent the repetition of the crop in the same field for at least 5 -8 years or soil disinfection is necessary. Chemical disinfection treatments have an uncertain future, in the European Union are reviewing their use, due to the effect on the non-pathogenic soil fauna. This situation causes a itinerant cultivation to avoid the limitations imposed by soil diseases, thereby increasing production costs. The Santa Monica Cooperative (Albacete, Spain) requested advice on possible alternative techniques, solarization and biosolarization. For which a trial was conducted to evaluate the effectiveness on the riverside area of the municipality. This place has recently authorized irrigation, which would allow the repeated cultivation of garlic if the incidence of soil diseases and the consequent soil fatigue could be avoided. Additionally, this work will serve to promote the cultivation of organic garlic. Last, but not least, the biosolarization technique allows to use waste from wineries, oil mills and mushroom crops. (Bello et al. 2003). The essay should serve as demonstrative proof for farmers' cooperative members. The specific objective for this first year is to assess, the effect on the global soil biota, on the final garlic production and quality and the effect of biosolarization to control soil pathogens. The trial is set on a cooperative's plot previously cultivated with corn. 5 treatments were set, defined by different amounts of organic matter applied, 7.5, 5, 2.5 kg m -2, a solarized with no organic matter, and a control without any treatment. The plot has inground sprinkler for full coverage with four sprinkler lines demarcating the five bands of differential treatment, randomly arranged. Organic matter was incorporated the August 14, 2013, then thoroughly

  5. California Immigrants Today

    OpenAIRE

    Cornelius, Wayne A.

    1990-01-01

    This paper will focus on the Mexico-origin component of the California immigrant population. Drawing on the results of field studies conducted throughout California and in west-central Mexico during the last ten years,the paper will describe how the profile of Mexican migration to California has changed since the 197Os, suggest explanations for these changes, and discuss their implications for public policy. Effects of the long-running economic crisis in Mexico and of the 1986 U.S. immigra-ti...

  6. Cell wall proteomics of crops

    Directory of Open Access Journals (Sweden)

    Setsuko eKomatsu

    2013-02-01

    Full Text Available Cell wall proteins play key roles in cell structure and metabolism, cell enlargement, signal transduction, responses to environmental stress, and many other physiological events. Agricultural crops are often used for investigating stress tolerance because cultivars with differing degrees of tolerance are available. Abiotic and biotic stress factors markedly influence the geographical distribution and yields of many crop species. Crop cell wall proteomics is of particular importance for improving crop productivity, particularly under unfavorable environmental conditions. To better understand the mechanisms underlying stress response in crops, cell wall proteomic analyses are being increasingly utilized. In this review, the methods of purification and purity assays of cell wall protein fractions from crops are described, and the results of protein identification using gel-based and gel-free proteomic techniques are presented. Furthermore, protein composition of the cell walls of rice, wheat, maize and soybean are compared, and the role of cell wall proteins in crops under flooding and drought stress is discussed. This review will be useful for clarifying the role of the cell wall of crops in response to environmental stresses.

  7. Crop drying programme in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Oztekin, S.; Bascetincelik, A.; Soysal, Y. [Cukurova Univ., Agricultural Machinery Dept., Adana (Turkey)

    1999-01-01

    The present status of agricultural crop drying practices in Turkey is investigated in this study. The emphasis of drying on market value, annual production and export values of some commercially important crops is given in a broad perspective. In the recent years, developing international market conditions in Europe, Middles East, and Central Asia has been encouraging to Turkey`s fresh and dry agricultural crop export due to the rapidly increasing internal and external market demands. Grapes, apricots, black tea, figs, red pepper, and medicinal and aromatic plants are the major exported agricultural crops, contributing annually 35 to 40 millions of USD$ to Turkey`s economics. From the view point of dried crop quality, drying of special crops are still an important topic for the agricultural sector. Traditionally used drying methods have many drawbacks. High air temperatures and relative humidity during the drying season promote the inset and mold development in harvested crops. Furthermore, the intensive solar radiation causes several quality reductions like vitamin losses of color changes in dried crops. Thus, the conventional drying methods do not meet the particular requirements of the related standards. To overcome these problems, producers should be made aware of the fact that the high quality of dried products can be sold to three of four fold prices and directed to the dryer investments. Moreover, the introduction of low cost and locally manufactured dryer offers a promising alternative to reduce the excessive postharvest losses and also improve the economical situation of the farmers. (Author)

  8. Analysis of rose crop production.

    NARCIS (Netherlands)

    Kool, M.T.N.; Koning, de J.C.M.

    1996-01-01

    Measured and simulated dry-matter production of two rose crops different in cultivar and growing conditions were compared. Differences in dry-matter production between the two crops could be explained to a large extend by differences in harvest index, leaf area index, supplementary lighting and

  9. Genetic Engineering and Crop Production.

    Science.gov (United States)

    Jones, Helen C.; Frost, S.

    1991-01-01

    With a spotlight upon current agricultural difficulties and environmental dilemmas, this paper considers both the extant and potential applications of genetic engineering with respect to crop production. The nonagricultural factors most likely to sway the impact of this emergent technology upon future crop production are illustrated. (JJK)

  10. Crop Protection in Medieval Agriculture

    NARCIS (Netherlands)

    Zadoks, J.C.

    2013-01-01

    Mediterranean and West European pre-modern agriculture (agriculture before 1600) was by necessity ‘organic agriculture’. Crop protection is part and parcel of this agriculture, with weed control in the forefront. Crop protection is embedded in the medieval agronomy text books but specialised

  11. Cassava as an energy crop

    DEFF Research Database (Denmark)

    Kristensen, Søren Bech Pilgaard; Birch-Thomsen, Torben; Rasmussen, Kjeld

    2014-01-01

    of the Attieké cassava variety. Little competition with food crops is likely, as cassava most likely would replace cotton as primary cash crop, following the decline of cotton production since 2005 and hence food security concerns appear not to be an issue. Stated price levels to motivate an expansion of cassava...

  12. Archives: African Crop Science Journal

    African Journals Online (AJOL)

    Items 1 - 50 of 98 ... Archives: African Crop Science Journal. Journal Home > Archives: African Crop Science Journal. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives. 1 - 50 of 98 ...

  13. Climate Impacts of Cover Crops

    Science.gov (United States)

    Lombardozzi, D.; Wieder, W. R.; Bonan, G. B.; Morris, C. K.; Grandy, S.

    2016-12-01

    Cover crops are planted in agricultural rotation with the intention of protecting soil rather than harvest. Cover crops have numerous environmental benefits that include preventing soil erosion, increasing soil fertility, and providing weed and pest control- among others. In addition to localized environmental benefits, cover crops can have important regional or global biogeochemical impacts by increasing soil organic carbon, changing emissions of greenhouse trace gases like nitrous oxide and methane, and reducing hydrologic nitrogen losses. Cover crops may additionally affect climate by changing biogeophysical processes, like albedo and latent heat flux, though these potential changes have not yet been evaluated. Here we use the coupled Community Atmosphere Model (CAM5) - Community Land Model (CLM4.5) to test how planting cover crops in the United States may change biogeophysical fluxes and climate. We present seasonal changes in albedo, heat fluxes, evaporative partitioning, radiation, and the resulting changes in temperature. Preliminary analyses show that during seasons when cover crops are planted, latent heat flux increases and albedo decreases, changing the evaporative fraction and surface temperatures. Understanding both the biogeophysical changes caused by planting cover crops in this study and the biogeochemical changes found in other studies will give a clearer picture of the overall impacts of cover crops on climate and atmospheric chemistry, informing how this land use strategy will impact climate in the future.

  14. Genetic control of rhizomes and genomic localization of a major-effect growth habit QTL in perennial wildrye.

    Science.gov (United States)

    Yun, Lan; Larson, Steve R; Mott, Ivan W; Jensen, Kevin B; Staub, Jack E

    2014-06-01

    Rhizomes are prostrate subterranean stems that provide primitive mechanisms of vegetative dispersal, survival, and regrowth of perennial grasses and other monocots. The extent of rhizome proliferation varies greatly among grasses, being absent in cereals and other annuals, strictly confined in caespitose perennials, or highly invasive in some perennial weeds. However, genetic studies of rhizome proliferation are limited and genes controlling rhizomatous growth habit have not been elucidated. Quantitative trait loci (QTLs) controlling rhizome spreading were compared in reciprocal backcross populations derived from hybrids of rhizomatous creeping wildrye (Leymus triticoides) and caespitose basin wildrye (L. cinereus), which are perennial relatives of wheat. Two recessive QTLs were unique to the creeping wildrye backcross, one dominant QTL was unique to the basin wildrye backcross, and one additive QTL was detectable in reciprocal backcrosses with high log odds (LOD = 31.6) in the basin wildrye background. The dominant QTL located on linkage group (LG)-2a was aligned to a dominant rhizome orthogene (Rhz3) of perennial rice (Oryza longistamina) and perennial sorghum (Sorghum propinquum). Nonparametric 99 % confidence bounds of the 31.6-LOD QTL were localized to a distal 3.8-centiMorgan region of LG-6a, which corresponds to a 0.7-Mb region of Brachypodium Chromosome 3 containing 106 genes. An Aux/IAA auxin signal factor gene was located at the 31.6-LOD peak, which could explain the gravitropic and aphototropic behavior of rhizomes. Findings elucidate genetic mechanisms controlling rhizome development and architectural growth habit differences among plant species. Results have possible applications to improve perennial forage and turf grasses, extend the vegetative life cycle of annual cereals, such as wheat, or control the invasiveness of highly rhizomatous weeds such as quackgrass (Elymus repens).

  15. The Study of Perennial Grasses and Legumes Mixtures in the Environmental Conditions Part 1: The Evolution of Mixtures Productivity from Someşelor Plateau

    Directory of Open Access Journals (Sweden)

    Dorin-Benone Pleşa

    2012-05-01

    Full Text Available Lately it is a high interest in the establishing of temporary grasslands, these being considered a valuable source of fodder from the quantitative and qualitative point of view. Temporary grasslands can be established instead of degraded permanent grasslands or in arable lands. In the paper are presented the results of the research which took place in 2010 and 2011, regarding the fodder evolution of a double factor experience; A factor – mixtures (8 complex mixtures of perennial grasses and legumes and one alfalfa pure crop, considered as a witness,B factor – levels of fertilization (0N0P2O5, 60N70P2O5,120N70P2O5 kg·ha-1. In 2010 the highest productions (13.16 SU t·ha-1 were obtained at all the cycles from the 5th mixture composed from red clover and 4 species of grasses Trifolium pratense L., Dactylis glomerata L., Festulolium Asch. & Graebn., Phleum pratense L., Lolium perenne L.. In 2011, mixture number 3, recognized as being recommended for the forest steppe area and composed from Lotus corniculatus L.,Onobrychis viciifolia Scop., Dactylis glomerata L., Festuca pratensis Huds., Bromus inermis Leyss, presented the highest productions (4.82 t·ha-1 for the 60N70P2O5 and 120N70P2O5 kg·ha-1 levels of fertilization.

  16. California Ocean Uses Atlas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a result of the California Ocean Uses Atlas Project: a collaboration between NOAA's National Marine Protected Areas Center and Marine Conservation...

  17. University of Southern California

    Data.gov (United States)

    Federal Laboratory Consortium — The focus of the University of Southern California (USC) Children''s Environmental Health Center is to develop a better understanding of how host susceptibility and...

  18. California Data Exchange Center

    Science.gov (United States)

    ... to make July &28;Water Smart Month.&29; &28;Conserving ... Remote sensors today indicate that statewide, snowpack water content is 54 percent of ... California ranked first, along with Texas, on ...

  19. Coastal California Digital Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This digital ortho-imagery dataset is a survey of coastal California. The project area consists of approximately 3774 square miles. The project design of the digital...

  20. Kelp distribution off California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set delineates kelp beds (Nereocystis leutkeana and Macrocystis spp.) along the Pacific Coast of California. Multiple years of kelp mapping data for the...

  1. California Harpoon Fishery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vessel logbook and landings data from harpoon vessels that fish within 200 miles of the California coast, from 1974 to present. The harpoon...

  2. Earthquakes in Southern California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — There have been many earthquake occurrences in Southern California. This set of slides shows earthquake damage from the following events: Imperial Valley, 1979,...

  3. California Watershed Hydrologic Units

    Data.gov (United States)

    California Department of Resources — This dataset is intended to be used as a tool for water-resource management and planning activities, particularly for site-specific and localized studies requiring a...

  4. Genome skimming reveals the origin of the Jerusalem Artichoke tuber crop species: neither from Jerusalem nor an artichoke.

    Science.gov (United States)

    Bock, Dan G; Kane, Nolan C; Ebert, Daniel P; Rieseberg, Loren H

    2014-02-01

    The perennial sunflower Helianthus tuberosus, known as Jerusalem Artichoke or Sunchoke, was cultivated in eastern North America before European contact. As such, it represents one of the few taxa that can support an independent origin of domestication in this region. Its tubers were adopted as a source of food and forage when the species was transferred to the Old World in the early 1600s, and are still used today. Despite the cultural and economic importance of this tuber crop species, its origin is debated. Competing hypotheses implicate the occurrence of polyploidization with or without hybridization, and list the annual sunflower H. annuus and five distantly related perennial sunflower species as potential parents. Here, we test these scenarios by skimming the genomes of diverse populations of Jerusalem Artichoke and its putative progenitors. We identify relationships among Helianthus taxa using complete plastomes (151 551 bp), partial mitochondrial genomes (196 853 bp) and 35S (8196 bp) and 5S (514 bp) ribosomal DNA. Our results refute the possibility that Jerusalem Artichoke is of H. annuus ancestry. We provide the first genetic evidence that this species originated recursively from perennial sunflowers of central-eastern North America via hybridization between tetraploid Hairy Sunflower and diploid Sawtooth Sunflower. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  5. Habitat change and plant demography: assessing the extinction risk of a formerly common grassland perennial.

    Science.gov (United States)

    Schleuning, Matthias; Matthies, Diethart

    2009-02-01

    An important aim of conservation biology is to understand how habitat change affects the dynamics and extinction risk of populations. We used matrix models to analyze the effect of habitat degradation on the demography of the declining perennial plant Trifolium montanum in 9 calcareous grasslands in Germany over 4 years and experimentally tested the effect of grassland management. Finite population growth rates (lambda) decreased with light competition, measured as leaf-area index above T. montanum plants. At unmanaged sites lambda was plants. Nevertheless, in stochastic simulations, extinction of unmanaged populations of 100 flowering plants was delayed for several decades. Clipping as a management technique rapidly increased population growth because of higher survival and flowering probability of large plants in managed than in unmanaged plots. Transition-matrix simulations from these plots indicated grazing or mowing every second year would be sufficient to ensure a growth rate > or =1 if conditions stayed the same. At frequently grazed sites, the finite growth rate was approximately 1 in most populations of T. montanum. In stochastic simulations, the extinction risk of even relatively small grazed populations was low, but about half the extant populations of T. montanum in central Germany are smaller than would be sufficient for a probability of survival of >95% over 100 years. We conclude that habitat change after cessation of management strongly reduces recruitment and survival of established individuals of this perennial plant. Nevertheless, our results suggest extinction processes may take a long time in perennial plants, resulting in an extinction debt. Even if management is frequent, many remnant populations of T. montanum may be at risk because of their small size, but even a slight increase in size could considerably reduce their extinction risk.

  6. Horticultural markets promote alien species invasions: an Estonian case study of herbaceous perennials

    Directory of Open Access Journals (Sweden)

    Merle Ööpik

    2013-06-01

    Full Text Available Gardening is a popular pastime, but commercial horticulture is responsible for the introduction of alien species and contributes to invasions in a variety of ways. Although an extensive international literature is available on plant invasions, it is still important at the national level to examine the influence of local factors. Accordingly, 17 nurseries in Estonia that cultivated and sold perennial alien species were selected, and a list of species and prices was compiled. The relationships between species status, and factors such as their abundance in the wild were examined statistically. A qualitative list of the nationally problematic species among herbaceous perennials was also completed. A total of 880 taxa were recorded, of which 10.3% were native and 89.7% alien. In all, 87.3% of the alien species were still confined to cultivated areas. The ecological and socio-economic characteristics of the taxa were described, and lists of the families of casual, naturalised and invasive aliens were provided. Both native and increasing wild alien species have a very similar profile on the market. Alien species that are less expensive, widely available and have more cultivars per species on the market are also more likely to escape. The invasive status and abundance of escaped aliens in an area increases with residence time. In general, socio-economic factors create new and reflect previous propagule pressures from commercial horticulture, which continuously increase the likelihood of alien species surviving and invading new areas. Our findings suggest that these national socio-economic market-related factors explain much of the invasiveness of various perennial ornamental species, and therefore regional and national authorities urgently need to regulate and control the ornamental plant trade to diminish the risk of new invasions.

  7. Immunomodulatory and antioxidant protective effect of Sarcocornia perennis L. (swampfire) in lead intoxicated rat.

    Science.gov (United States)

    Gargouri, Manel; Hamed, Houda; Akrouti, Amel; Christian, Magné; Ksouri, Riadh; El Feki, Abdelfattah

    2017-11-01

    Lead (Pb) is a very toxic metal present in the environment, causing disturbances of several functions. Preventive or curative effects of halophytic plants against these disorders may be a promising and safe therapeutic strategy. Thus, this study was designed to evaluate in vivo immunomodulatory and antioxidant effects of Sarcocornia perennis extract (Sp) against lead toxicity in rats. Groups of six animals each were treated with plant extract (via food), 6 g/L lead acetate (via drinking water) or a combination of both. At the end of the three-week period, rat exposure to lead caused reduction of liver weight but an increase of that of kidney. Moreover, lead intoxication-induced oxidative stress manifested by significant increases of inflammatory cytokines (except IL-10) and lipid peroxidation (TBARS), compared with the control group. Meanwhile, interleukin-10 (IL-10) and glutathione levels (GSH), as well as antioxidant activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were decreased. Considering liver and renal markers, lead treatment induced a significant increase in the activities of aminotransferases (AST, ALT), and in the levels of urea, creatinine and phosphorous, whereas total plasma protein, albumin and calcium levels were significantly decreased. S. perennis extract alone did not induce any significant changes in hepatic or renal markers, whereas the antioxidant markers were significantly increased. S. perennis supplementation significantly reduced the lead-induced elevation of serum IL-1ß, IL-6, TNF-α, IFN-γ and TBARS but increased the IL-10 and antioxidant enzyme activities. Overall, plant components ameliorated hepatorenal damages caused by lead.

  8. Key plant structural and allocation traits depend on relative age in the perennial herb Pimpinella saxifraga.

    Science.gov (United States)

    Niinemets, Ulo

    2005-08-01

    Perennial plant formations always include a mixture of various-aged individuals of community-creating species, but the physiological and competitive potentials of plants of differing age and the importance on whole community functioning are still not entirely known. The current study tested the hypothesis that ontogenetically old plants have limited biomass investments in leaves and enhanced foliage support costs. Leaf structure, size and biomass allocation were studied in the perennial herb Pimpinella saxifraga during plant ontogeny from seedling to senile phases to determine age-dependent controls on key plant structural traits. The average duration of the full ontogenetic cycle is approx. 5-10 years in this species. Plants were sampled from shaded and open habitats. Leaflet dry mass per unit area (M(A)) increased, and the fraction of plant biomass in leaflets (F(L)) decreased with increasing age, leading to a 5- to 11-fold decrease in leaf area ratio (LAR = F(L)/M(A)) between seedlings and senescent plants. In contrast, the fraction of below-ground biomass increased with increasing age. Leaflet size and number per leaf increased with increasing age. This was not associated with enhanced support cost in older plants as age-dependent changes in leaf shape and increased foliage packing along the rachis compensated for an overall increase in leaf size. Age-dependent trends were the same in habitats with various irradiance, but the LAR of plants of varying age was approx. 1.5-fold larger in the shade due to lower M(A) and larger F(L). As plant light interception per unit total plant mass scales with LAR, these data demonstrate major age-dependent differences in plant light-harvesting efficiency that are further modified by site light availability. These ontogenetic changes reduce the differences among co-existing species in perennial communities, and therefore need consideration in our understanding of how herbaceous communities function.

  9. Gene Cloning and Expression of the Pyrroline-5-carboxylate Reductase Gene of Perennial Ryegrass (Lolium perenne

    Directory of Open Access Journals (Sweden)

    Cao Li

    2015-09-01

    Full Text Available Salt and drought limit the range of applications of perennial ryegrass (Lolium perenne L., which is one of the important turf and forage grasses. Previous studies have suggested that pyrroline-5-carboxylate reductase (P5CR might play a central role in proline accumulation in plants that are responsive to stresses. In the present study, the Lolium perenne L. pyrroline-5-carboxylate reductase (LpP5CR gene was cloned from leaves of the cultivar ‘Derby’ using the RACE technique. The full-length LpP5CR gene was 1 047 bp in length, which comprised an open reading frame (ORF of 840 bp in size. Sequence alignment revealed that the putative LpP5CR had a 94.3% similarity to TaP5CR. qRT-PCR displayed that the mRNA levels of the LpP5CR gene were almost the same as that in the roots, stems, and leaves of perennial ryegrass seedlings subjected to normal condition or NaCl treatment for 1 h. Moreover, the transcription level of LpP5CR was up- or down-regulated with NaCl, polyethylene glycol (PEG, cold, or abscisic acid (ABA treatment for 3 to 48 h. In addition, confocal microscopy localized the GFP-LpP5CR fusion protein to the cytoplasm of onion epidermal cells. These findings suggest that LpP5CR encodes a cytoplasmic P5CR protein that plays an important role in the response of perennial ryegrass to various stresses.

  10. Sheep numbers required for dry matter digestibility evaluations when fed fresh perennial ryegrass or forage rape

    Directory of Open Access Journals (Sweden)

    Xuezhao Sun

    2017-03-01

    Full Text Available Research trials with fresh forages often require accurate and precise measurement of digestibility and variation in digestion between individuals, and the duration of measurement periods needs to be established to ensure reliable data are obtained. The variation is likely to be greater when freshly harvested feeds are given, such as perennial ryegrass (Lolium perenne L. and forage rape (Brassica napus L., because the nutrient composition changes over time and in response to weather conditions. Daily feed intake and faeces output data from a digestibility trial with these forages were used to calculate the effects of differing lengths of the measurement period and differing numbers of sheep, on the precision of digestibility, with a view towards development of a protocol. Sixteen lambs aged 8 months and weighing 33 kg at the commencement of the trial were fed either perennial ryegrass or forage rape (8/treatment group over 2 periods with 35 d between measurements. They had been acclimatised to the diets, having grazed them for 42 d prior to 11 days of indoor measurements. The sheep numbers required for a digestibility trial with different combinations of acclimatisation and measurement period lengths were subsequently calculated for 3 levels of imposed precision upon the estimate of mean dry matter (DM digestibility. It is recommended that if the standard error of the mean for digestibility is equal to or higher than 5 g/kg DM, and if sheep are already used to a fresh perennial ryegrass or forage rape diet, then a minimum of 6 animals are needed and 4 acclimatisation days being fed individually in metabolic crates followed by 7 days of measurement.

  11. 78 FR 55171 - Common Crop Insurance Regulations; Processing Sweet Corn Crop Insurance Provisions

    Science.gov (United States)

    2013-09-10

    ... Federal Crop Insurance Corporation 7 CFR Part 457 RIN 0563-AC37 Common Crop Insurance Regulations; Processing Sweet Corn Crop Insurance Provisions AGENCY: Federal Crop Insurance Corporation, USDA. ACTION: Final rule. SUMMARY: The Federal Crop Insurance Corporation (FCIC) finalizes the Common Crop Insurance...

  12. 76 FR 75805 - Common Crop Insurance Regulations; Prune Crop Insurance Provisions

    Science.gov (United States)

    2011-12-05

    ... Federal Crop Insurance Corporation 7 CFR Part 457 RIN 0563-AC36 Common Crop Insurance Regulations; Prune Crop Insurance Provisions AGENCY: Federal Crop Insurance Corporation, USDA. ACTION: Proposed rule. SUMMARY: The Federal Crop Insurance Corporation (FCIC) proposes to amend the Common Crop Insurance...

  13. 78 FR 13454 - Common Crop Insurance Regulations; Pecan Revenue Crop Insurance Provisions

    Science.gov (United States)

    2013-02-28

    ... Federal Crop Insurance Corporation 7 CFR Part 457 RIN 0563-AC35 Common Crop Insurance Regulations; Pecan Revenue Crop Insurance Provisions AGENCY: Federal Crop Insurance Corporation, USDA. ACTION: Final rule. SUMMARY: The Federal Crop Insurance Corporation (FCIC) finalizes the Common Crop Insurance Regulations...

  14. Cropping Pattern Detection and Change Analysis in Central Luzon, Philippines Using Multi-Temporal MODIS Imagery and Artificial Neural Network Classifier

    Science.gov (United States)

    dela Torre, D. M.; Perez, G. J. P.

    2016-12-01

    Cropping practices in the Philippines has been intensifying with greater demand for food and agricultural supplies in view of an increasing population and advanced technologies for farming. This has not been monitored regularly using traditional methods but alternative methods using remote sensing has been promising yet underutilized. This study employed multi-temporal data from MODIS and neural network classifier to map annual land use in agricultural areas from 2001-2014 in Central Luzon, the primary rice growing area of the Philippines. Land use statistics derived from these maps were compared with historical El Nino events to examine how land area is affected by drought events. Fourteen maps of agricultural land use was produced, with the primary classes being single-cropping, double-cropping and perennial crops with secondary classes of forests, urban, bare, water and other classes. Primary classes were produced from the neural network classifier while secondary classes were derived from NDVI threshold masks. The overall accuracy for the 2014 map was 62.05% and a kappa statistic of 0.45. 155.56% increase in single-cropping systems from 2001 to 2014 was observed while double cropping systems decreased by 14.83%. Perennials increased by 76.21% while built-up areas decreased by 12.22% within the 14-year interval. There are several sources of error including mixed-pixels, scale-conversion problems and limited ground reference data. An analysis including El Niño events in 2004 and 2010 demonstrated that marginally irrigated areas that usually planted twice in a year resorted to single cropping, indicating that scarcity of water limited the intensification allowable in the area. Findings from this study can be used to predict future use of agricultural land in the country and also examine how farmlands have responded to climatic factors and stressors.

  15. Weather and Management Effects over Nine Years of Net Ecosystem Direct Greenhouse Gas Emissions from a Cropping System in the Red River Valley, Manitoba

    Science.gov (United States)

    Tenuta, M.; Amiro, B. D.

    2014-12-01

    Variation in weather and crop management practices strongly determines direct greenhouse gas emissions (CO2 and N2O) from agricultural crop land. Thus a long-term study was established to relate weather and management variations to direct emissions in the Northern Great Plains of Canada. Continuously emission determinations of CO2 and N2O were established at the Trace Gas Manitoba (TGAS-MAN) Long Term Greenhouse Gas Monitoring Site at Glenlea, Manitoba, using the flux gradient micrometeorlogical technique with a tunable diode laser analyzer. The soil is poorly drained clay in the Red River Valley. The field experiment consisted of four 4-hectare plots planted to corn in 2006 and faba bean in 2007. In 2008, grass-alfalfa forage was introduced to two plots (annual - perennial) and grown until 2011 whereas the other two plots (annual) were planted to annual crops: spring wheat, rapeseed, barley and spring wheat in 2008, 2009, 2010 and 2011, respectively. In late September of 2011 the grass-alfalfa forage was killed and in 2012, 2013 and 2014 all four plots were planted with corn, soybean and spring wheat, respectively. Management decisions increased emissions such as fertilizer N addition, and hay, straw and silage crop removal greatly increased emissions while choosing legume grain and perennial crops reduced emissions. Weather variation affecting seasonal and daily soil moisture, length of spring freeze-thaw period, and crop yield served to increase or decrease emissions. The variation in management and weather will be discussed in regards to impact on net emissions over the nine year study and answer if development of greenhouse gas neutral cropping systems is possible.

  16. QTL analysis of crown rust resistance in perennial ryegrass under conditions of natural and artificial infection

    DEFF Research Database (Denmark)

    Schejbel, Britt; Jensen, Louise Friis Bach; Xing, Yongzhong

    2007-01-01

    Crown rust is an economically devastating disease of perennial ryegrass. Both artificial crown rust inoculations, with the possibility of several selection cycles in one year, as well as marker-assisted selection can be used for more efficient breeding of new resistant cultivars. The objective...... as well as by artificial pathogen inoculations using a detached leaf assessment. The broad sense heritability values for the field, detached leaf and combined assays were 0.42, 0.56, and 0.64, respectively, indicating a good potential for selection for crown rust resistance. A total of six QTLs were...

  17. Genetic linkage mapping in an F2 perennial ryegrass population using DArT markers

    DEFF Research Database (Denmark)

    Tomaszewski, Céline; Byrne, Stephen; Foito, Alexandra

    2012-01-01

    Perennial ryegrass is the principal forage grass species used in temperate agriculture. In recent years, significant efforts have been made to develop molecular marker strategies to allow cost-effective characterization of a large number of loci simultaneously. One such strategy involves using DAr......T markers, and a DArT array has recently been developed for the Lolium-Festuca complex. In this study, we report the first use of the DArTFest array to generate a genetic linkage map based on 326 markers in a Lolium perenne F2 population, consisting of 325 genotypes. For proof of concept, the map was used...

  18. EVALUATION OF PERFORMANCE PARAMETERS FOR TRACE ELEMENTS ANALYSIS IN PERENNIAL PLANTS

    OpenAIRE

    ŞENILĂ MARIN; ŞENILĂ LĂCRIMIOARA; ROMAN CECILIA

    2011-01-01

    The aim of this paper is to present the validation of inductively coupled plasma optical emission spectrometry (ICP-OES) method used for metals determination from several perennial plant samples. The suitability of two digestion procedures using wet digestion with mineral acids mixture on hot plate and microwave digestion was investigated to determine As, Cd, Cu, Fe, Mn, Pb and Zn in plants samples. The LOD of the seven analysed elements in solid samples varied between 0.20µg g-1 for Mn and 0...

  19. Automatic image cropping for republishing

    Science.gov (United States)

    Cheatle, Phil

    2010-02-01

    Image cropping is an important aspect of creating aesthetically pleasing web pages and repurposing content for different web or printed output layouts. Cropping provides both the possibility of improving the composition of the image, and also the ability to change the aspect ratio of the image to suit the layout design needs of different document or web page formats. This paper presents a method for aesthetically cropping images on the basis of their content. Underlying the approach is a novel segmentation-based saliency method which identifies some regions as "distractions", as an alternative to the conventional "foreground" and "background" classifications. Distractions are a particular problem with typical consumer photos found on social networking websites such as FaceBook, Flickr etc. Automatic cropping is achieved by identifying the main subject area of the image and then using an optimization search to expand this to form an aesthetically pleasing crop. Evaluation of aesthetic functions like auto-crop is difficult as there is no single correct solution. A further contribution of this paper is an automated evaluation method which goes some way towards handling the complexity of aesthetic assessment. This allows crop algorithms to be easily evaluated against a large test set.

  20. Recycling crop residues for use in recirculating hydroponic crop production

    Science.gov (United States)

    Mackowiak, C. L.; Garland, J. L.; Sager, J. C.

    1996-01-01

    As part of bioregenerative life support feasibility testing by NASA, crop residues are being used to resupply elemental nutrients to recirculating hydroponic crop production systems. Methods for recovering nutrients from crop residues have evolved from water soaking (leaching) to rapid aerobic bioreactor processing. Leaching residues recovered the majority of elements but it also recovered significant amounts of soluble organics. The high organic content of leachates was detrimental to plant growth. Aerobic bioreactor processing reduced the organic content ten-fold, which reduced or eliminated phytotoxic effects. Wheat and potato production studies were successful using effluents from reactors having with 8- to 1-day retention times. Aerobic bioreactor effluents supplied at least half of the crops elemental mass needs in these studies. Descriptions of leachate and effluent mineral content, biomass productivity, microbial activity, and nutrient budgets for potato and wheat are presented.