WorldWideScience
1

Crop rotations that include legumes and reduced tillage improve the energy efficiency of crop production systems  

Science.gov (United States)

Text: Modern crop production requires large inputs of energy and these inputs represent a substantial cost. Management practices such as crop rotation and choice of tillage practice influence the energy balance for a production system. Legumes support bacteria that are capable of fixing nitrogen (N)...

2

Recycling of crop residues for sustainable crop production in a maize-groundnut rotation system  

International Nuclear Information System (INIS)

A long-term field experiment, which was established to investigate the contribution of crop residues to the N-economy of a maize-groundnut rotation system, consisted of three treatments: (i) T1, the recommended rate of chemical fertilizer with residue, (ii) T2, the recommended rate of chemical fertilizer without residue, and (iii) T3, a combination of organic fertilizer (chicken manure) and chemical fertilizer with residue. In order to investigate the N contribution from residues of the first crop (maize) to subsequent crops, the maize was labelled with 15N in the T1 and T2 treatments. Fertilizer N (15N-ammonium sulphate, 9.82% a.e.) was applied (60 kg N ha-1) to microplots within each yield plot, to generate labelled maize residue. At the same time 90 kg N ha-1 unlabelled N fertilizer was applied to provide the recommended rate for maize of 150 kg Nha-1. Uptake of N and K by subsequent crops was significantly higher in crop-residue treatments, whereas uptake of P, Ca and Mg was not significantly affected. Soil pH, organic C, cation-exchange capacity, soil resistance, water content and bulk density were not significantly changed after four crop-residue applications. Soil organic matter size and density fractions seemed to increase, with application of residues, but without statistical significance. Soil available P and exchangeable K were significantly higher in plots with crop residues. Recovery of fertilizer 15Nues. Recovery of fertilizer 15N by the first crop ranged from 19 to 22%. In the following crop, the recoveries were only 5.1% and 5.6% in plants of T1 and T2 treatment and only trace recoveries of 15N occurred in the subsequent crop. Fertilizer 15N retained in the soil after harvest of the first crop was 35 to 44%, whereas after the second crop 33% was present in crop-residue treated plots and 26% in plots where crop residues had been removed. Nitrogen mineralization from maize residues was quite rapid from 4 to 8 weeks after incorporation due to the hot, humid conditions. Thus, for good synchrony of release of N from residues and uptake of N by the crop, sowing should be 4 to 6 weeks after residue incorporation. However, in a rain-fed area it is sometimes inevitable that fallow periods are long, i.e. more than 6 weeks, depending on the rainfall, as in this study. Contributions of crop residues to economic yields were not significant, even after six crop cycles. (author)

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Diversity of segetal weeds in pea (Pisum sativum L. depending on crops chosen for a crop rotation system  

Directory of Open Access Journals (Sweden)

Full Text Available This study, lasting from 1999 to 2006, was conducted at the Research Station in Tomaszkowo, which belongs to the University of Warmia and Mazury in Olsztyn. The experiment was set up on brown rusty soil classified as good rye complex 5 in the Polish soil valuation system. The analysis comprised weeds in fields sown with pea cultivated in two four-field crop rotation systems with a different first crop: A. potato – spring barley – pea – spring barley; B. mixture of spring barley with pea – spring barley – pea – spring barley. Every year, at the 2–3 true leaf stage of pea, the species composition and density of individual weed species were determined; in addition, before harvesting the main crop, the dry matter of weeds was weighed. The results were used to analyze the constancy of weed taxa, species diversity, and the evenness and dominance indices, to determine the relationships between all biological indicators analyzed and weather conditions, and to calculate the indices of similarity, in terms of species composition, density and biomass of weeds, between the crop rotations compared.The species richness, density and biomass of weeds in fields with field pea were not differentiated by the choice of the initial crop in a given rotation system. In the spring, the total number of identified taxa was 28 and it increased to 36 before the harvest of pea plants. Chenopodium album and Echinochloa crus-galli were the most numerous. Chenopodium album, Echinochloa crus-galli, Sonchus arvensis, Fallopia convolvulus and Viola arvensis were constant in all treatments, regardless of what the first crop in rotation was or when the observations were made.The species diversity and the evenness and species dominance indices varied significantly between years and dates of observations. Species diversity calculated on the basis of the density of weed species was higher in the rotation with a mixture of cereals and legumes, while that calculated on the basis of weed biomass was higher in the system with potato. The similarity indices, which express the convergence of floristic composition as well as of the density and biomass of weeds growing in pea fields in the two crop rotation systems compared, were within a broad range (42–86%. The biodiversity of weed communities was more closely correlated to total precipitation than to air temperature.

Marta K. Kostrzewska

2014-04-01

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Evaluation of soil quality indicators in paddy soils under different crop rotation systems  

Science.gov (United States)

Evaluation of soil quality indicators in paddy soils under different crop rotation systems Soil quality, by definition, reflects the capacity to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. Soil quality assessment is an essential issue in soil management for agriculture and natural resource protection. This study was conducted to detect the effects of four crop rotation systems (rice-rice-rice, soya-rice-rice, fallow-rice and pea-soya-rice) on soil quality indicators (soil moisture, porosity, bulk density, water-filled pore space, pH, extractable P, CEC, OC, OM, microbial respiration, active carbon) in paddy soils of Verona area, Northern Italy. Four adjacent plots which managed almost similarly, over five years were selected. Surface soil samples were collected from each four rotation systems in four times, during growing season. Each soil sample was a composite of sub-samples taken from 3 points within 350 m2 of agricultural land. A total of 48 samples were air-dried and passed through 2mm sieve, for some chemical, biological, and physical measurements. Statistical analysis was done using SPSS. Statistical results revealed that frequency distribution of most data was normal. The lowest CV% was related to pH. Analysis of variance (ANOVA) and comparison test showed that there are significant differences in soil quality indicators among crop rotation systems and sampling times. Results of multivariable regression analysis revealed that soil respiration had positively correlation coefficient with soil organic matter, soil moisture and cation exchange capacity. Overall results indicated that the rice rotation with legumes such as bean and soybean improved soil quality over a long time in comparison to rice-fallow rotation, and this is reflected in rice yield. Keywords: Soil quality, Crop Rotation System, Paddy Soils, Italy

Nadimi-Goki, Mandana; Bini, Claudio; Haefele, Stephan; Abooei, Monireh

2013-04-01

5

Energy crops in rotation. A review  

Energy Technology Data Exchange (ETDEWEB)

The area under energy crops has increased tenfold over the last 10 years, and there is large consensus that the demand for energy crops will further increase rapidly to cover several millions of hectares in the near future. Information about rotational systems and effects of energy crops should be therefore given top priority. Literature is poor and fragmentary on this topic, especially about rotations in which all crops are exclusively dedicated to energy end uses. Well-planned crop rotations, as compared to continuous monoculture systems, can be expected to reduce the dependence on external inputs through promoting nutrient cycling efficiency, effective use of natural resources, especially water, maintenance of the long-term productivity of the land, control of diseases and pests, and consequently increasing crop yields and sustainability of production systems. The result of all these advantages is widely known as crop sequencing effect, which is due to the additional and positive consequences on soil physical-chemical and biological properties arising from specific crops grown in the same field year after year. In this context, the present review discusses the potential of several rotations with energy crops and their possibilities of being included alongside traditional agriculture systems across different agro-climatic zones within the European Union. Possible rotations dedicated exclusively to the production of biomass for bioenergy are also discussed, as rotations including only energy crops could become common around bio-refineries or power plants. Such rotations, however, show some limitations related to the control of diseases and to the narrow range of available species with high production potential that could be included in a rotation of such characteristics. The information on best-known energy crops such as rapeseed (Brassica napus) and sunflower (Helianthus annuus) suggests that conventional crops can benefit from the introduction of energy crops in the rotation; furthermore, a considerable number of lesser-known energy crops such as biomass sorghum (Sorghum spp.), hemp (Cannabis sativa), kenaf (Hibiscus cannabinus), Ethiopian mustard (Brassica carinata) could be expected to lead to even greater benefits according to literature. Therefore, this review aimed at systematizing and reorganizing the existing and fragmentary information on these crops while stressing major knowledge gaps to be urgently investigated. (author)

Zegada-Lizarazu, Walter; Monti, Andrea [Department of Agroenvironmental Science and Technology, University of Bologna, Viale G. Fanin, 44 - 40127, Bologna (Italy)

2011-01-15

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Maize response to different straw management and tillage systems under cereal crop rotation  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study was to determine the effect of various straw management and tillage systems on the emergence, grain yield and cob characteristics of maize (Zea mays L. under different cereal rotations on two soils (Orthic Luvisols of loamy sand and sandy loam textures. The study was conducted in 1999, 2002 and 2003 in a micro-plot (1x1 m experiment. Concrete walls, 120 cm deep, separated each plot of 1x1 m (five replicates. Straw management systems included: removed straw (RS and left straw (LS in the amount of annual straw yield. The retained straw was chopped and spread by hand. Under each straw management system the three following tillage systems were applied: conventional tillage (CT, reduced tillage (RT, no-tillage (NT with sowing to the uncultivated soil and chemical weed control. Each treatment had five replicates giving a total of sixty micro-plots. The preceding crops of maize were rye, winter wheat or maize, depending on the soil and year. The same maize varieties were used in both soils (Antares in 1999-2000 and Matilda in 2003. There was a tendency towards poorer maize emergence in plots with retained straw compared to removed straw under no-tillage system compared to conventionally tilled system in both soils. The results indicated that the reduced tillage systems in combination with chopped straw can be applied on the studied soils without any significant decrease in maize grain yield.

A. Biskupski

2006-06-01

7

[Effects of different multiple cropping systems on paddy field weed community under long term paddy-upland rotation].  

Science.gov (United States)

Based on a long term field experiment, this paper studied the effects of different multiple cropping systems on the weed community composition and species diversity under paddy-upland rotation. The multiple cropping rotation systems could significantly decrease weed density and inhibited weed growth. Among the rotation systems, the milk vetch-early rice-late maize --> milk vetchearly maize intercropped with early soybean-late rice (CCSR) had the lowest weed species dominance, which inhibited the dominant weeds and decreased their damage. Under different multiple cropping systems, the main weed community was all composed of Monochoia vaginalis, Echinochloa crusgalli, and Sagittaria pygmae, and the similarity of weed community was higher, with the highest similarity appeared in milk vetch-early rice-late maize intercropped with late soybean --> milk vetch-early maize-late rice (CSCR) and in CCSR. In sum, the multiple cropping rotations in paddy field could inhibit weeds to a certain extent, but attentions should be paid to the damage of some less important weeds. PMID:24417111

Yang, Bin-Juan; Huang, Guo-Qin; Xu, Ning; Wang, Shu-Bin

2013-09-01

8

Recycling of crop-residue N for sustainable production in maize-groundnut rotation system  

International Nuclear Information System (INIS)

To investigate the contribution of crop residues to the N-economy of a maize-groundnut rotation, a long-term field experiment was established in February 1997. It consisted of the following treatments: (i) T1 - the recommended rate of chemical fertilizer plus residues, (ii) T2 - the recommended rate of chemical fertilizer without residues, and (iii) T3 - a combination of organic fertilizer (chicken dung), chemical fertilizer, and residues. In order to investigate the possible contribution of residue N to subsequent crops, the first maize crop was labelled with 15N. The first crop was sown in March 1997 and 15N-labelled ammonium sulphate was applied at 60 kg N ha-1 to the T1 and T2 treatments, in microplots within yield plots, to generate labelled maize residues. At the same time, 90 kg N ha-1 unlabelled N fertilizer was applied to provide the locally recommended rate for maize of 150 kg N ha-1. Treatment T3 was included for comparison of yields and appraisal of effects on soil properties. After the first crop was harvested, the labelled aboveground residues in T1 were applied to a different microplot so that the fate of the labelled residue-N could be followed. Groundnut was grown in rotation with maize, and, after each harvest, the labelled aboveground residues in the microplots of T1 and T2 were removed and unlabeland T2 were removed and unlabelled residues were added to T1. Because variability between replicates was high in the treatment T2, the average yields in plots with residues, T1 and T3, in the second and third crop cycles were not significantly different from those without residues. Maize yields were similar in the first and second years

9

Recycling of crop-residue N for sustainable production in a maize-groundnut rotation system  

International Nuclear Information System (INIS)

To investigate the contribution of crop residues to the N-economy of a maize-groundnut rotation, a long-term field experiment was established in February 1997. It consisted of the following treatments: (i) T1 - the recommended rate of chemical fertilizer plus residues, (ii) T2 - the recommended rate of chemical fertilizer without residues, and (iii) T3 - a combination of organic fertilizer (chicken dung), chemical fertilizer, and residues. In order to investigate the possible contribution of residue N to subsequent crops, the first maize crop was labelled with 15N. The first crop was sown in March 1997 and 15N-labelled ammonium sulphate was applied at 60 kg N ha-1 to the T1 and T2 treatments, in microplots within yield plots, to generate labelled maize residues. At the same time, 90 kg N ha-1 unlabelled N fertilizer was applied to provide the locally recommended rate for maize of 150 kg N ha-1. Treatment T3 was included for comparison of yields and appraisal of effects on soil properties. After the first crop was harvested, the labelled aboveground residues in T1 were applied to a different microplot so that the fate of the labelled residue-N could be followed. Groundnut was grown in rotation with maize, and, after each harvest, the labelled aboveground residues in the microplots of T1 and T2 were removed and unlabeland T2 were removed and unlabelled residues were added to T1. Because variability between replicates was high in the treatment T2, the average yields in plots with residues, T1 and T3, in the second and third crop cycles were not significantly different from those without residues. Maize yields were similar in the first and second years

10

Regional variability of environmental effects of energy crop rotations  

Science.gov (United States)

The use of energy crops for bioenergy production is increasingly promoted by different frameworks and policies (ECCP, UNFCCC). Energy cropping decreases greenhouse gas emissions by replacing the use of fossil fuel. However, despite this, growing in monocultures energy crop rotations has low environmental benefit. It is broadly accepted consensus that sustainable energy cropping is only realizable by crop rotations which include several energy crop species. Four crop rotations consisting of species mixtures of C3, C4 and leguminous plants and their crop positions were tested to identify the environmental effect of energy cropping systems. The experimental design included four replicates per crop rotation each covering four cultivation years. The study took place at five sites across Germany covering a considerable range of soil types (loamy sand to silt loam), temperatures (7.5 ° C - 10.0 ° C) and precipitation (559 mm - 807 mm) which allow a regional comparison of crop rotation performance. Four indicators were used to characterize the environmental conditions: (1) greenhouse gas (GHG) emissions from the management actions; (2) change in humus carbon (Chum); (3) groundwater recharge (RGW) and (4) nitrogen dynamics. The indicators were derived by balance, by an empirical model and by a dynamic model, respectively, all based and calibrated on measured values. The results show that the crop rotation impact on environmental indicators varied between plant species mixtures and the crop positions, between sites and climate. Crop rotations with 100 % energy crops (including C4 plants) had negative influence on Chum, GHG emissions per area and RGW in comparison to the rotation of 50 % energy crops and 50 % cash crops, which were mainly due to the remaining straw on the field. However, the biogas yield of the latter rotation was smaller, thus GHG emissions per product were higher, pointing out the importance to distinguish between GHG emissions per product and per area. The perennial legume rotation was identified as the most beneficial and eco-friendly energy crop rotation by showing an increase in Chum, lower GHG emissions per product and area and positive effects on nitrogen dynamics. However, the absolute magnitude of changes and effects differs between the sites indicating an influence of soil type and local climate on the final performance of the energy crop rotation. Generally, the results showed that the positive effect of a certain crop rotation on particular environmental indicators can have a less beneficial effect on another indicator, making an overall evaluation of the energy crop rotation complicated. The weighing of different environmental indicators finally depends on the environmental priorities, political targets and describes a further challenge.

Prescher, Anne-Katrin; Peter, Christiane; Specka, Xenia; Willms, Matthias; Glemnitz, Michael

2014-05-01

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Crop rotation impact on soil quality  

International Nuclear Information System (INIS)

Management systems influence soil quality over time. A study was carried out on Van meter farm of the Ohio State University South Centers at Piketon Ohio, USA to evaluate the impact of crop rotations on soil quality from 2002 to 2007. The crop rotations comprised of continuous corn (CC), corn-soybean (CS) and corn-soybean-wheat-cowpea (CSW). Ten soil cores were collected at 0-7.5, 7.5-15, 15-22.5 and 22.5-30 cm, and sieved. The soils were analyzed for total microbial biomass (C/sub mic/), basal respiration (BR) and specific maintenance respiration (qCO/sub 2/) rates as biological quality indicators; total organic carbon (TC), active carbon (AC) and total nitrogen (TN) as chemical quality indicators; and aggregate stability (AS), particulate organic matter (POM) and total porosity (ft) as physical quality parameters at different depths of soil. The inductive additive approach based on the concept of 'higher value of any soil property except ft, a better indicator of soil quality' was used to calculate the biological (SBQ), chemical (SCQ), physical (SPQ) and composite soil quality (SQI) indices. The results showed that crop rotation had significant impact on C/sub mic/, BR, qCO/sub 2/, TC, AC, TN, AS and POM except ft at different depths of soil. The CSW had higher soil quality values than CC and CS. The values of selected soil quality properties under the given crop rotation significantly decreased except ft with increasing soil depth. The SBQ (23%), SCQ (16%), SPQ (7%l depth. The SBQ (23%), SCQ (16%), SPQ (7%) and SQI (15%) improved under CSW over time. The results imply that multiple cropping systems could be more effective for maintaining and enhancing soil quality than sole-cropping systems. (author)

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Short rotation Wood Crops Program  

Energy Technology Data Exchange (ETDEWEB)

This report synthesizes the technical progress of research projects in the Short Rotation Woody Crops Program for the year ending September 30, 1989. The primary goal of this research program, sponsored by the US Department of Energy's Biofuels and Municipal Waste Technology Division, is the development of a viable technology for producing renewable feedstocks for conversion to biofuels. One of the more significant accomplishments was the documentation that short-rotation woody crops total delivered costs could be $40/Mg or less under optimistic but attainable conditions. By taking advantage of federal subsidies such as those offered under the Conservation Reserve Program, wood energy feedstock costs could be lower. Genetic improvement studies are broadening species performance within geographic regions and under less-than-optimum site conditions. Advances in physiological research are identifying key characteristics of species productivity and response to nutrient applications. Recent developments utilizing biotechnology have achieved success in cell and tissue culture, somaclonal variation, and gene-insertion studies. Productivity gains have been realized with advanced cultural studies of spacing, coppice, and mixed-species trials. 8 figs., 20 tabs.

Wright, L.L.; Ehrenshaft, A.R.

1990-08-01

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Sequential Decision Rules for Managing Nematodes with Crop Rotations  

OpenAIRE

A dynamic model of nematode populations under a crop rotation that includes both host and nonhost crops is developed and used to conceptualize the problem of economic control. The steady state of the dynamic system is used to devise an approximately optimal decision policy, which is then applied to cyst nematode (Heterodera schachtii) control in a rotation of sugarbeet with nonhost crops. Long-run economic returns from this approximately optimal decision rule are compared with results from so...

Burt, O. R.; Ferris, H.

1996-01-01

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Assessment of soil biological quality index (QBS-ar) in different crop rotation systems in paddy soils  

Science.gov (United States)

New methods, based on soil microarthropods for soil quality evaluation have been proposed by some Authors. Soil microarthropods demonstrated to respond sensitively to land management practices and to be correlated with beneficial soil functions. QBS Index (QBS-ar) is calculated on the basis of microarthropod groups present in a soil sample. Each biological form found in the sample receives a score from 1 to 20 (eco-morphological index, EMI), according to its adaptation to soil environment. The objective of this study was to evaluate the effect of various rotation systems and sampling periods on soil biological quality index, in paddy soils. For the purpose of this study surface soil samples (0-15 cm depth) were collected from different rotation systems (rice-rice-rice, soya-rice-rice, fallow-rice and pea-soya-rice) with three replications, and four sampling times in April (after field preparation), June (after seedling), August (after tillering stage) and October (after rice harvesting). The study area is located in paddy soils of Verona area, Northern Italy. Soil microarthropods from a total of 48 samples were extracted and classified according to the Biological Quality of Soil Index (QBS-ar) method. In addition soil moisture, Cumulative Soil Respiration and pH were measured in each site. More diversity of microarthropod groups was found in June and August sampling times. T-test results between different rotations did not show significant differences while the mean difference between rotation and different sampling times is statistically different. The highest QBS-ar value was found in the fallow-rice rotation in the forth soil sampling time. Similar value was found in soya-rice-rice rotation. Result of linear regression analysis indicated that there is significant correlation between QBS-ar values and Cumulative Soil Respiration. Keywords: soil biological quality index (QBS-ar), Crop Rotation System, paddy soils, Italy

Nadimi-Goki, Mandana; Bini, Claudio; haefele, Stephan

2013-04-01

15

[Dynamics of polycyclic aromatic hydrocarbons (PAHs) in the paddy-soil system during the crop rotation process].  

Science.gov (United States)

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in the paddy root-soil system were determined to study the dynamic and the influencing factors during crop rotation period. It showed that the dynamic of PAHs in paddy roots was most correlative with the factor of root surface area, but less correlated with PAHs in air and particles, which indicates that the physiological characters rather than the environment media are the main factors influencing the PAHs accumulation in paddy roots. According to the EPA risk standard about BaP and sigma PAHs, the PAHs accumulation in the paddy seeds won't decrease the food security to human being. The PAHs concentrations in paddy soil showed a declined trend during the period of paddy growth, which was affected not only by the processes of water elution and microbe degradation, but also depended on the absorption rate of paddy roots. When the crop rotation begins and paddy planting rolls into the next growing period, the PAHs in the paddy soil will again increase into a higher level which is correlated with the TOC content in the soil. PMID:20825036

Jiao, Xing-chun; Ye, Chuan-yong; Chen, Su-hua; Yang, Yong-liang; Wu, Zhen-yan

2010-07-01

16

Irrigation management of crops rotations in a changing climate  

Science.gov (United States)

Due to climate change we cannot continue to perform irrigation systems design and irrigation management based only on historical records of weather stations, assuming that the statistical parameters of the meteorological data remains unchanged in time, being necessary to take into account the climatic data relative to climate change scenarios. For the Mediterranean basin the various climate models indicate an increase in temperature and a reduction in precipitation and a more frequent occurrence of extreme events which will increase the risk of crop failure. Thus, it is important to adopt strategies to ensure the sustainability of irrigated agriculture in a changing climate. A very interesting technique to achieve this is the adoption of crops rotations, since they increase the heterogeneity of farming systems distributing the risk between crops and minimizing costs. This study aims to evaluate the impact of climate change in the irrigation requirements of crop rotations for the Alentejo region in the South of Portugal, and the ability of crops rotation to reduce these impacts and stabilize crops production. The IrrigRotation software was used to estimate the water requirements of two crop rotations used in the Alentejo region, Sunflower-Wheat-Barley and Sugar beet-Maize-Tomato-Wheat. IrrigRotation is a soil water balance simulation model, continuous in time, based on the dual crop coefficients methodology, which allows to compute the irrigation requirements of crop rotations. The climate data used were the observed data of the Évora and Beja weather stations (1961-90), the A2 and B2 scenarios of the HadRM3P model and the A2 scenarios of the HIRHAMh and HIRHAMhh models (2071-2100). The consideration of a set of climate change scenarios produces as a result a range of values for the irrigation requirements which can be used to define safety margins in irrigation design. The results show that for the Beja clay soils, with high values of soil water storage capacity, the crops rotations can decrease the water deficit of the rainfed crops cultivated after the irrigated crops. This is due to the storage of water in the deepest soil layers during the irrigated crops with shallow roots that increase the available soil water at the planting date of the wheat crop. For the soils with small water storage capacity and small depth, such as the Évora silt-clay-sandy soil, it was not observed the benefic effects of crops rotation in the reduction of the water deficit of the rainfed crops. The results obtained for the several climate change scenarios (2071-2100) show an increase in irrigation requirements between 13% and 70%, with the higher values corresponding to the Autumn-Winter crops (sugar beet), due to the combined effect of an increased evapotranspiration and a reduced precipitation during the crop cycle. The irrigation requirements for the peak period increased between 10% to 46%. For the climate change scenarios it was also found an increased risk of crop failure for the rainfed crops, with a water deficit value for the wheat ranging between 32% to 59%, and for the barley ranging between 34% to 45%. Keywords: Crops Rotation, Soil water balance, Irrigation, Climate change, Model

Rolim, J.; Teixeira, J.; Catalão, J.

2012-04-01

17

Impacts of projected climate change on productivity and nitrogen leaching of crop rotations in arable and pig farming systems in Denmark  

DEFF Research Database (Denmark)

The effects of projected changes in climate and atmospheric CO2 concentration on productivity and nitrogen (N) leaching of characteristic arable and pig farming rotations in Denmark were investigated with the FASSET simulation model. The LARS weather generator was used to provide climatic data for the baseline period (1961–90) and in combination with two regional circulation models (RCM) to generate climatic data under the Intergovernmental Panel on Climate Change (IPCC) A1B emission scenario for four different 20-year time slices (denoted by midpoints 2020, 2040, 2060 and 2080) for two locations in Denmark, differing in soil and climate, and representative of the selected production systems. The CO2 effects were modelled using projected CO2 concentrations for the A1B emission scenario. Crop rotations were irrigated (sandy soil) and unirrigated (sandy loam soil), and all included systems with and without catch crops, with field operation dates adapted to baseline and future climate change. Model projections showed an increase in the productivity and N leaching in the future that would be dependent on crop rotation and crop management, highlighting the importance of considering the whole rotation rather than single crops for impact assessments. Potato and sugar beet in arable farming and grain maize in pig farming contributed most to the productivity increase in the future scenarios. The highest productivity was obtained in the arable system on the sandy loam soil, with an increase of 20% on average in 2080 with respect to the baseline. Irrigation and fertilization rates would need to be increased in the future to achieve optimum yields. Growing catch crops reduces N leaching, but current catch crop management might not be sufficient to control the potential increase of leaching and more efficient strategies are required in the future. The uncertainty of climate change scenarios was assessed by using two different climate projections for predicting crop productivity and N leaching in Danish crop rotations, and this showed the consistency of the projected trends when used with the same crop model

Doltra, Jordi; Lægdsmand, Mette

2014-01-01

18

Rainfed intensive crop systems  

DEFF Research Database (Denmark)

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.

Olesen, JØrgen E

2014-01-01

19

Three-year measurements of nitrous oxide emissions from cotton and wheat-maize rotational cropping systems  

Science.gov (United States)

The remarkable expansion of fertilization and irrigation may stimulate nitrous oxide (N2O) emissions from cropping systems in northern China. High-resolution measurements were conducted in irrigated cotton and wheat-maize rotational systems in Shanxi Province, P.R. China, between 2007 and 2010 (three year-round crop cycles, hereinafter referred to as Y1, Y2 and Y3) to investigate the impacts of natural inter-annual variations and agricultural management on annual N2O emissions and direct emission factors (EFs). Overall, N2O emissions fluctuated diurnally, seasonally and inter-annually in the fertilized treatments. The hourly N2O fluxes closely followed the daily air temperature patterns. The daily mean fluxes corresponded to these hourly fluxes, which were observed between 09:00-10:00 and 19:00-20:00. An optimized sampling protocol could improve the reliability of discrete measurements when estimating cumulative emissions. The N2O emissions for the fertilized treatments were 2.7 ± 0.2 (Y1) and 1.6 ± 0.1 kg N ha-1 yr-1 (Y2) from the cotton field and 6.2 ± 0.4 (Y1), 4.5 ± 0.3 (Y2) and 4.5 ± 0.2 kg N ha-1 yr-1 (Y3) from the wheat-maize field. Peak N2O emissions after fertilization and irrigation/rainfall lasted one to three weeks and accounted for 16-55% of the annual emissions. Leaching losses were estimated at 10.4 ± 3.0 (Y1) and 12.5 ± 3.4 kg N ha-1 yr-1 (Y2), which accounted for 16-17% of the fertilizer-N applied to the cotton field. Annual N2O emissions did not increase with increasing fertilization rates or water inputs because significant amounts of fertilizer-N were lost through leaching. Background emissions amounted to one-third to one-half of the total N2O emissions from the fertilized treatments. The direct EFs were 2.2 ± 0.3% (Y1) and 0.9 ± 0.2% (Y2) in the cotton field and 1.3 ± 0.2% (Y1), 0.8 ± 0.1% (Y2) and 0.7 ± 0.1% (Y3) in the wheat-maize field. The large inter-annual variations in N2O emissions and direct EFs emphasize the importance of multiple-year continuous observations.

Liu, Chunyan; Yao, Zhisheng; Wang, Kai; Zheng, Xunhua

2014-10-01

20

Nitrogen cycling in organic farming systems with rotational grass-clover and arable crops  

DEFF Research Database (Denmark)

Organic farming is considered an effective means of reducing nitrogen losses compared with more intensive conventional farming systems. However, under certain conditions, organic farming may also be susceptible to large nitrogen (N) losses. This i especially the case for organic .....

Berntsen, JØrgen; Grant, Ruth

2006-01-01

21

Dinâmica e contribuição da micorriza arbuscular em sistemas de produção com rotação de culturas / Dynamics and contribution of arbuscular mycorrhiza in culture systems with crop rotation  

Scientific Electronic Library Online (English)

Full Text Available Rotação de culturas e variações sazonais podem promover alterações quantitativas e qualitativas na comunidade de fungos micorrízicos arbusculares nativos e na formação da micorriza arbuscular. Essa dinâmica foi avaliada, em campo, num Latossolo Vermelho, em relação ao tempo de cultivo e variação saz [...] onal, em sistemas de rotação de culturas. Em casa de vegetação, avaliou-se, em solo proveniente da área experimental, a contribuição da micorriza arbuscular no crescimento de soja e capim-andropógon utilizados na rotação. O número de esporos dos fungos aumentou no solo cultivado. O número de esporos e o porcentual de colonização radicular, inicialmente maiores sob pastagem, variaram de acordo com o tempo de cultivo, as estações seca e chuvosa, a cultura e o sistema de rotação utilizados. O número de gêneros e espécies aumentou com o tempo de cultivo e manejo de culturas e foi maior sob culturas anuais em rotação. A presença dos fungos no solo contribuiu no crescimento da soja e do capim-andropógon em 53% e 95%, respectivamente. A cultura e o sistema de cultivo são fatores determinantes para o enriquecimento do sistema com micorriza arbuscular. Abstract in english Crop rotation and seasonal variations can promote quantitative and qualitative changes in the indigenous arbuscular mycorrhizal fungi population in the soil and arbuscular mycorrhiza establishment. These fungi dynamics were evaluated in the field, in a Red Latosol, in relation to cropping time, seas [...] onal variation and rotation systems. The contribution of arbuscular mycorrhiza to the growth of andropogon grass and soybean, which were used in the systems, was evaluated in a greenhouse experiment using soil from the experimental area. The number of spores of the fungi increased in the cultivated soil. The spores number and percent root colonization varied according to cropping time, soil moisture, crops and rotation system and were, initially, higher under pasture. The number of genus and species increased according to cropping time and culture management and was higher under annual crops in rotation. The presence of these fungi in the soil contributed 53% and 95% to the growth of soybean and andropogon grass, respectively. Crops and cultivation system are crucial for the system's enrichment in arbuscular mycorrhiza.

Jeanne Christine Claessen de, Miranda; Lourival, Vilela; Leo Nobre de, Miranda.

1005-10-01

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Carbon footprints of crops from organic and conventional arable crop rotations – using a life cycle assessment approach  

DEFF Research Database (Denmark)

Many current organic arable agriculture systems are challenged by a dependency on imported livestock manure from conventional agriculture. At the same time organic agriculture aims at being climate friendly. A life cycle assessment is used in this paper to compare the carbon footprints of different organic arable crop rotations with different sources of N supply. Data from long-term field experiments at three different locations in Denmark were used to analyse three different organic cropping systems (‘Slurry’, ‘Biogas’ and ‘Mulching’), one conventional cropping system (‘Conventional’) and a “No input” system as reference systems. The ‘Slurry’ and ‘Conventional’ rotations received slurry and mineral fertilizer, respectively, whereas the ‘No input’ was unfertilized. The ‘Mulching’ and ‘Biogas’ rotations had one year of grass-clover instead of a faba bean crop. The grass-clover biomass was incorporated in the soil in the ‘Mulching’ rotation and removed and used for biogas production in the ‘Biogas’ rotation (and residues from biogas production were simulated to be returned to the field). A method was suggested for allocating effects of fertility building crops in life cycle assessments. The results showed significantly lower carbon footprint of the crops from the ‘Biogas’ rotation (assuming that biogas replaces fossil gas) whereas the remaining crop rotations had comparable carbon footprints per kg cash crop. The study showed considerable contributions caused by the green manure crop (grass-clover) and highlights the importance of analysing the whole crop rotation and including soil carbon changes when estimating carbon footprints of organic crops especially where green manure crops are included.

Knudsen, Marie Trydeman; Meyer-Aurich, A

2014-01-01

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JET SYSTEM OF MIXTURE OF FERTILIZERS AT FERTIGATION IRRIGATION CROP ROTATION OF TOMATOES AND CUCUMBERS FOR CULTIVATION IN THE PROTECTED SOIL IN THE CONDITIONS OF THE ROSTOV REGION  

Directory of Open Access Journals (Sweden)

Full Text Available In this article the scheme of landing of early tomatoes and cucumbers in the climatic conditions of the Rostov region is described; we have also calculated the dose of fertilizers for jet system of mixture at a fertigation irrigation. The conclusion is drawn with a possibility of cultivation crop rotation of tomatoes and cucumbers in not heated greenhouses with application of fertilizers

Degtyareva K. A.

2014-04-01

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Accounting for soil biotic effects on soil health and crop productivity in the design of crop rotations.  

Science.gov (United States)

There is an urgent need for novel agronomic improvements capable of boosting crop yields while alleviating environmental impacts. One such approach is the use of optimized crop rotations. However, a set of measurements that can serve as guiding principles for the design of crop rotations is lacking. Crop rotations take advantage of niche complementarity, enabling the optimization of nutrient use and the reduction of pests and specialist pathogen loads. However, despite the recognized importance of plant-soil microbial interactions and feedbacks for crop yield and soil health, this is ignored in the selection and management of crops for rotation systems. We review the literature and propose criteria for the design of crop rotations focusing on the roles of soil biota and feedback on crop productivity and soil health. We consider that identifying specific key organisms or consortia capable of influencing plant productivity is more important as a predictor of soil health and crop productivity than assessing the overall soil microbial diversity per se. As such, we propose that setting up soil feedback studies and applying genetic sequencing tools towards the development of soil biotic community databases has a strong potential to enable the establishment of improved soil health indicators for optimized crop rotations. PMID:24408021

Dias, Teresa; Dukes, Angela; Antunes, Pedro M

2015-02-01

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How can we improve Mediterranean cropping systems?  

DEFF Research Database (Denmark)

In the Mediterranean region, crop productivity and food security are closely linked to the adaptation of cropping systems to multiple abiotic stresses. Limited and unpredictable rainfall and low soil fertility have reduced agricultural productivity and environmental sustainability. For this reason, crop management technologies have been developed, with a special focus on the Mediterranean region, to enhance crop production by increasing land productivity and sustaining soil fertility under influence of climate changes and population increases. The main objective of this study was to analyse dryland Mediterranean cropping systems, and to discuss and recommend sustainable cropping technologies that could be used at the small-scale farm level. Four crop management practices were evaluated: crop rotations, reduced tillage, use of organic manure, and supplemental and deficit irrigation. Among the tested interventions, incorporation of crop residues coupled with supplementary irrigation showed a significantly positive effect on crop productivity, yield stability and environmental sustainability.

Benlhabib, O.; Yazar, A.

2014-01-01

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Alterações na fertilidade do solo em sistemas de rotação de culturas em semeadura direta / Soil fertility changes on no-tillage crop rotation systems  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O sistema de semeadura direta com culturas de grãos ocupa atualmente 2,5 milhões de hectares no estado do Paraná. Além do sistema tradicional de sucessão trigo-soja, em grande parte desta área são semeadas plantas de cobertura-adubação verde no inverno e milho no verão. Neste estudo, foram avaliadas [...] as alterações em algumas características químicas do solo, após sete anos, sob os sistemas de rotação de culturas trigo-soja-aveia-soja (TSA), trigo-soja-tremoço-milho-aveia-soja (TMA), tremoço-milho-trigo-soja (TM) e o sistema tradicional de sucessão trigo-soja (TS) em unidades de Latossolo Roxo distrófico, em Londrina e Campo Mourão. O sistema TM diminuiu o pH do solo e os teores de cálcio (Ca2+) e magnésio (Mg2+) trocáveis e aumentou o alumínio trocável (Al3+), a acidez potencial (H + Al) e o N-total do solo em relação ao sistema TS. Essas caracaterísticas apresentaram valores intermediários nos demais sistemas. Não foram observadas diferenças entre os sistemas quanto aos teores de carbono orgânico e potássio trocável (K+) no solo. A diminuição do teor de Ca2+ no sistema TM foi maior do que a quantidade de Ca aplicado na forma de calcário durante o experimento. A adubação nitrogenada no trigo e no milho foi relacionada com a acidificação observada no solo. A manutenção dos níveis de K+ e diminuição dos níveis de Ca2+ e Mg2+ resultaram provavelmente de uma alteração na preferência de lixiviação de cátions no sistema TM. A formação de complexos orgânicos com cátions divalentes foi sugerida como provável mecanismo responsável por estas alterações químicas no solo. Abstract in english The no-tillage system with grain crops occupies today 2.5 millions hectares in the state of Paraná. Besides the traditional rotation system with wheat and soybean, in many areas green manure cover crops are also sown in the Winter and corn in the Summer. The objective of this study was to evaluate c [...] hanges in some of the soil chemical properties after eight years under the crop rotation systems: wheat-soybean-black oat-soybean (WOS), wheat-soybean-lupine-corn-black oat-soybean (LCO), lupine-corn-wheat-soybean (LC) and compare them with the traditional system wheat-soybean (WS) grown in two Oxisols at Londrina and Campo Mourão, State of Paraná, Brazil. The LC crop rotation system reduced the soil pH and the level of exchangeable calcium (Ca2+) and magnesium (Mg2+) and increased the excangeable aluminum (Al3+), the potential acidity (H + Al), and the total-N in the soil as compared to the WS system. These characteristics showed intermediate values in the other systems. There were no significant differences on soil levels of organic carbon and exchangeable-K (K+) among the crop rotation systems. The decrease on the level of Ca2+ in the LC system was larger than the amount of Ca applied as lime to the soil during the experiment. Soil acidification was related to the nitrogen fertilization of wheat and corn. The maintenance of levels of K+ and the decrease on the levels of Ca2+ and Mg2+ demonstrate that there was a change in the preference of leaching cations in the LC crop rotation system. The formation of metal-organic complexes with divalent cations was assumed to be the possible mechanism responsible for the chemical alterations in the soil.

J. C., Franchini; C. M., Borkert; M. M., Ferreira; C. A., Gaudêncio.

2000-06-01

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The role of short-rotation woody crops in sustainable development  

International Nuclear Information System (INIS)

One answer to increase wood production is by increasing management intensity on existing timberland, especially in plantation forests. Another is to convert land currently in agriculture to timberland. Short-rotation woody crops can be used in both cases. But, what are the environmental consequences? Short-rotation woody crops can provide a net improvement in environmental quality at both local and global scales. Conversion of agricultural land to short-rotation woody crops can provide the most environmental quality enhancement by reducing erosion, improving soil quality, decreasing runoff, improving groundwater quality, and providing better wildlife habitat. Forest products companies can use increased production from intensively managed short-rotation woody crop systems to offset decreased yield from the portion of their timberland that is managed less intensively, e.g. streamside management zones and other ecologically sensitive or unique areas. At the global scale, use of short-rotation woody crops for bioenergy is part of the solution to reduce greenhouse gases produced by burning fossil fuels. Incorporating short-rotation woody crops into the agricultural landscape also increases storage of carbon in the soil, thus reducing atmospheric concentrations. In addition, use of wood instead of alternatives such as steel, concrete, and plastics generally consumes less energy and produces less greenhouse gases. Cooperative research can be used to achieve energy, fiber, and environmental goals. This paper will highlight several examples of ongoing cooperative research projects that seek to enhance the environmental aspects of short-rotation woody crop systems. Government, industry, and academia are conducting research to study soil quality, use of mill residuals, nutrients in runoff and groundwater, and wildlife use of short-rotation woody crop systems in order to assure the role of short-rotation crops as a sustainable way of meeting society's needs

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From Monoculture to Norfolk System: How the Number of Crops in Rotation Can Influence the Biodiversity of Arbuscular Mycorrhiza Assemblages in the Soil  

Directory of Open Access Journals (Sweden)

Full Text Available Given the attention drawn since several decades by arbuscular mycorrhizal fungi (AMF as potential biological alternatives to chemicals in a low-input agriculture, much effort has been spent in the investigation of mechanisms influencing the dynamics inside AMF communities. In the present study we evaluated the influence of different crop rotations on the AMF soil community, after a 50 y long-term field experiment established at Martonvásár, Hungary. Four types of crop rotation were chosen for sampling: corn monocropping, corn-alfalfa, corn-wheat, and corn-spring barley-peas-wheat. Community composition of AMF in soil was analyzed with a molecular approach amplifying a portion of 28S rDNA. The crop rotation practice didn’t show an influence on identity of the species composing AMF assemblages, but on the other hand seemed to affect positively the true diversity, defined as number of MOTUs present in the communities.

Franco Magurno

2014-12-01

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Evaluation of Maize Yield in an On-Farm Maize-Soybean and Maize-Lablab Crop Rotation Systems in the Northern Guinea Savanna of Nigeria  

OpenAIRE

An attempt was made to solving the problem of shortfall of fertilizer to maize production in the Northern Guinea Savanna (NGS) of Nigeria by harnessing the potentials of legume/cereal crop rotation in on-farm trials. The yield of maize that succeeded two soybean varieties and Lablab in a two-cycle of soybean/maize and Lablab/maize crop rotation in NGS Nigeria was assessed in researcher-managed and farmer-managed plots. Though maize that followed the soybean received between 5 kg N ha-1 from i...

Okogun, J. A.; Sanginga, N.; Abaidoo, R. C.

2007-01-01

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Faba bean in cropping systems  

DEFF Research Database (Denmark)

The grain legume (pulse) faba bean (Vicia faba L.) is grown world-wide as a protein source for food and feed. At the same time faba bean offers ecosystem services such as renewable inputs of nitrogen (N) into crops and soil via biological N2 fixation, and a diversification of cropping systems. Even though the global average grain yield has almost doubled during the past 50 years the total area sown to faba beans has declined by 56% over the same period. The season-to-season fluctuations in grain yield of faba bean and the progressive replacement of traditional farming systems, which utilized legumes to provide N to maintain soil N fertility, with industrialized, largely cereal-based systems that are heavily reliant upon fossil fuels (=N fertilizers, heavy mechanization) are some of the explanations for this decline in importance. Past studies of faba bean in cropping systems have tended to focus on the effect of faba bean as a pre-crop in mainly cereal intensive rotations, whereas similar information on the effect of preceding crops on faba bean is lacking. Faba bean has the highest average reliance on N2 fixation for growth of the major cool season grain legumes. As a consequence the N benefit for following crops is often high, and several studies have demonstrated substantial savings (up to 100–200 kg N ha?1) in the amount of N fertilizer required to maximize the yield of crops grown after faba bean. There is, however, a requirement to evaluate the potential risks of losses of N from the plant–soil system associated with faba bean cropping via nitrate leaching or emissions of N2O to the atmosphere as a consequence of the rapid mineralization of N from its N-rich residues. It is important to develop improved preventive measures, such as catch crops, intercropping, or no-till technologies, in order to provide farmers with strategies to minimize any possible undesirable effects on the environment that might result from their inclusion of faba bean in cropping system. This needs to be combined with research that can lead to a reduction in the current extent of yield variability, so that faba bean may prove to be a key component of future arable cropping systems where declining supplies and high prices of fossil energy are likely to constrain the affordability and use of fertilizers. This will help address the increasing demand by consumers and governments for agriculture to reduce its impact on the environment and climate through new, more sustainable approaches to food production. The aims of this paper are to review the role of faba bean in global plant production systems, the requirements for optimal faba bean production and to highlight the beneficial effects of faba bean in cropping systems.

Steen Jensen, Erik; Peoples, Mark B.

2010-01-01

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Sistemas de preparo do solo e rotação de culturas na produtividade de milho, soja e trigo Tillage systems and crop rotation on yield of corn, soybean and wheat  

Directory of Open Access Journals (Sweden)

Full Text Available Com este trabalho, objetivou-se determinar quanto os sistemas de preparo do solo e as rotações de culturas afetam a produtividade de grãos do milho, da soja e do trigo. O experimento foi conduzido em um Latossolo Vermelho distrófico, em área irrigada por pivô central, na EMBRAPA Arroz e Feijão, em Santo Antônio de Goiás, GO, por seis anos, setembro de 1992 a setembro de 1998, durante os quais foram feitos 12 cultivos e comparados três sistemas de preparo do solo: a aração com arado de aiveca, realizada em novembro-dezembro e em maio-junho; b aração com grade aradora, em ambos os períodos, e c plantio direto e quatro rotações de cultura: 1 milho-feijão; 2 soja-trigo; 3 soja-trigo-soja-feijão-arroz-feijão e 4 milho-feijão-milho-feijão-arroz-feijão. As culturas de arroz, soja e milho, foram semeadas em novembro-dezembro e as de feijão e trigo, em maio-junho. Para efeito do estudo, consideraram-se somente as culturas do milho, da soja e do trigo. O sistema de preparo do solo não afetou a produtividade de soja mas, sim, a de milho e de trigo, tendo o preparo com arado propiciado maiores produtividades em comparação com o plantio direto. As diferenças entre o plantio direto e os demais sistemas de preparo do solo, com relação à produtividade acumulada relativa de milho, diminuíram com o tempo de cultivo. Não houve efeito da rotação de culturas sobre a produtividade das culturas estudadas.The objective of this study was to determine how much soil tillage and crop rotation affected grain yield of corn, soybean and wheat. The study was carried out at EMBRAPA (Rice and Beans, in Santo Antônio de Goiás, GO, Brazil, in a Red Latosol (Oxisol, under center pivot irrigation system, for six consecutive years. During the experimentation, 12 crops were cultivated. The tillage treatments were a moldboard plough, b harrow disc and c no-tillage. The crop rotations were 1 corn-bean, 2 soybean-wheat, 3 soybean-wheat-soybean-bean-upland rice-bean and 4 corn-bean-corn bean-upland rice-bean. Rice, soybean and corn were sown in November/December and bean and wheat in May/June. For this study, only corn, soybean and wheat were considered. Soil tillage affected corn and wheat yields but did not affect soybean yield. Corn and wheat yields under mouldboard plough were higher than under no-tillage. The differences among no-tillage and the other tillage systems in relation to relative accumulative corn yield decreased as the cultivation period increased. Crop rotations did not affect the crop yields.

Pedro M. da Silveira

2003-08-01

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Maize nitrogen fertilization in two crop rotation systems under no-till / Adubação nitrogenada para o milho em dois sistemas de rotação de culturas sob plantio direto  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Com o objetivo de avaliar o parcelamento de doses de nitrogênio (N), aplicadas na semeadura e em cobertura do milho, com e sem rotação de culturas, em semeadura direta, foi realizado um experimento com seis doses de N na semeadura (0, 20, 30, 40, 50 e 60 kg ha-1), combinadas com três doses em cobert [...] ura (40, 70, 100 kg ha-1) e dois sistemas de manejo: após cinco cultivos de milho e com rotação de culturas (milho+soja+aveia+soja+milho), em delineamento de blocos casualizados, com quatro repetições. O sistema de rotação de culturas proporcionou incremento de aproximadamente 7%, no rendimento de grãos, em relação ao da área sem rotação. O parcelamento da adubação nitrogenada, com doses acima de 39 e 54 kg ha-1, na semeadura, com 70 e 40 kg ha-1, em cobertura, respectivamente, resultou em produtividade superior à obtida com aplicação de 100 kg ha-1, em cobertura. O rendimento de grãos foi maior com o parcelamento da dose de 50 e 70 kg ha-1 de N, na semeadura e cobertura, em comparação com o obtido com o parcelamento de 20 e 100 kg ha-1, na semeadura e cobertura, respectivamente. A dose de 70 kg ha-1 de N em cobertura apresentou maior produtividade de grãos com menor custo, em comparação com os rendimentos e custos verificados em relação às doses de 40 e 100 kg ha-1. Abstract in english The objective of this study was to evaluate split nitrogen (N) fertilization of maize applied in band at sowing and top dressing with and without crop rotation, under no-till. The experiment was conducted with six N rates at sowing (0, 20, 30, 40, 50 and 60 kg ha-1) combined with three rates in top [...] dressing (40, 70, 100 kg ha-1) and two management systems: after five cropping sequences of maize and crop rotation (maize + soybean + oat + soybean + corn) in a randomized block design with four replications. The crop rotation system increased yield in approximately 7% in relation to the area without rotation. The split of nitrogen fertilization, in rates above 39 and 54 kg ha-1 at sowing and 70 and 40 kg ha-1 in top dressing, resulted in yield higher than that obtained with the application of 100 kg ha-1 in top dressing. Grain yield was higher with the rates 50 and 70 kg ha-1 of N compared with that obtained with 20 and 100 kg ha-1 at sowing and top dressing, respectively. The rate 70 kg ha-1 of N resulted in the highest yield at the lowest cost compared with the revenues and costs incurred with the rates 40 and 100 kg ha-1.

Maria do Carmo, Lana; Rodrigo Vianei, Czycza; Jean Sérgio, Rosset; Jucenei Fernando, Frandoloso.

2013-12-01

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Grain yield and agronomic traits in soybean according to crop rotation systems / Rendimento de grãos e características agronômicas de soja em função de sistemas de rotação de culturas  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar o efeito dos sistemas de rotação de culturas (SRC) sobre o rendimento de grãos e as características agronômicas de soja no período de 1996/1997 a 2010/2011 em Latossolo Vermelho distrófico típico, na Embrapa Trigo, em Passo Fundo, RS. Foram comparados quatro tip [...] os de manejo de solo (TMS): 1) sistema plantio direto (SPD); 2) cultivo mínimo (CM); 3) preparo convencional de solo com arado de discos (PCD); e 4) preparo convencional de solo com arado de aivecas (PCA) e três SRC: sistema I (monocultura de trigo/monocultura de soja); sistema II (trigo/soja e ervilhaca/milho ou sorgo); e III (trigo/soja, aveia branca/soja e ervilhaca/milho ou sorgo). O delineamento experimental foi em blocos completos ao acaso, com parcelas subdivididas e três repetições. A parcela foi constituída pelos TMS, e as subparcelas, pelos SRC. No presente trabalho serão abordados somente os dados sobre sistemas de rotação de culturas. A análise conjunta dos dados obtidos não indicou diferença entre os SRC em relação ao número de grãos por planta, à massa de mil grãos e à altura de inserção das primeiras vagens de soja. A rotação de culturas por um verão utilizando milho ou sorgo propicia maior rendimento de grãos de soja em comparação com os demais sistemas estudados e com a soja em monocultura. A combinação de sistemas conservacionistas (SPD e CM) e SRC favoreceu o maior rendimento de grãos de soja. Os menores rendimentos de grãos e massa de grãos ocorreram em monocultura de soja. Abstract in english The effects of crop rotation systems (CRS) on soybean yield and agronomic characteristics were evaluated from 1996/1997 to 2010/2011 at Embrapa Trigo, Passo Fundo (RS), Brazil. Four soil management systems (SMS) were compared, namely: 1) no tillage, 2) minimum tillage, 3) conventional tillage using [...] a disk plow and a disk harrow, and 4) conventional using a moldboard and a disk harrow - and three CRS: system I (wheat/soybean), system II (wheat/soybean and common vetch/corn or sorghum) and system III (wheat/soybean, white oats/soybean and common vetch/corn or sorghum). This is a split-plot, randomized, complete block design with three replications. SMS were assigned in the main plot and CRS systems in the split-plots. This work addressed only data on crop rotation systems. There were no significant differences between the CRS for number of grains per plant, 1,000 grain weight and first pod height in soybean. The crop rotation for a summer, with corn or sorghum, propitiates a higher soybean yield compared with the other systems and monoculture soybean. The combination of conservation systems (no tillage and minimum tillage) and CR resulted in a higher soybean yield. The lowest grain yield and grain weight per plant were obtained in monoculture soybean.

Henrique Pereira dos, Santos; Renato Serena, Fontaneli; João, Pires; Evandro Ademir, Lampert; Ana Maria, Vargas; Amauri Colet, Verdi.

2014-09-01

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Energy performances of intensive and extensive short rotation cropping systems for woody biomass production in the EU.  

Czech Academy of Sciences Publication Activity Database

Ro?. 41, JAN 2015 (2015), s. 845-854. ISSN 1364-0321 R&D Projects: GA MŠk EE2.3.30.0056 Institutional support: RVO:67179843 Keywords : poplar * willow * bioenergy crops * energy balance * energy efficiency Subject RIV: BO - Biophysics Impact factor: 5.510, year: 2013

Djomo, S. N.; A?, Alexander; Zenone, T.; De Groote, T.; Bergante, S.; Facciotto, G.; Sixto, H.; Ciria Ciria, P.; Weger, J.; Ceulemans, R.

2015-01-01

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Crop rotation biomass and arbuscular mycorrhizal fungi effects on sugarcane yield  

Energy Technology Data Exchange (ETDEWEB)

Sugarcane (Saccharum spp.) is an important crop for sugar production and agro-energy purposes in Brazil. In the sugarcane production system after a 4- to 8-year cycle crop rotation may be used before replanting sugarcane to improve soil conditions and give an extra income. This study had the objective of characterizing the biomass and the natural colonization of arbuscular mycorrhizal fungi (AMF) of leguminous green manure and sunflower (Helianthus annuus L.) in rotation with sugarcane. Their effect on stalk and sugar yield of sugarcane cv. IAC 87-3396 grown subsequently was also studied. Cane yield was harvested in three subsequent cuttings. Peanut cv. IAC-Caiapo, sunflower cv. IAC-Uruguai and velvet bean (Mucuna aterrimum Piper and Tracy) were the rotational crops that resulted in the greater percentage of AMF. Sunflower was the specie that most extracted nutrients from the soil, followed by peanut cv. IAC-Tatu and mung bean (Vigna radiata L. Wilczek). The colonization with AMF had a positive correlation with sugarcane plant height, at the first cut (p = 0.01 and R = 0.52) but not with the stalk or cane yields. Sunflower was the rotational crop that brought about the greatest yield increase of the subsequent sugarcane crop: 46% increase in stalk yield and 50% in sugar yield compared with the control. Except for both peanut varieties, all rotational crops caused an increase in net income of the cropping system in the average of three sugarcane harvests. (author)

Ambrosano, Edmilson Jose; Rossi, Fabricio; Guirado, Nivaldo; Teramoto, Juliana Rolim Salome [Agencia Paulista de Tecnologia dos Agronegocios (APTA), Piracicaba, SP (Brazil). Polo Regional Centro Sul; Azcon, Rozario [Consejo Superior de Investigaciones Cientificas (CSIC), Granada (Spain). Estacao Experimental de Zaidin; Cantarela, Heitor [Agencia Paulista de Tecnologia dos Agronegocios (APTA/IAC), Campinas, SP (Brazil). Inst. Agronomico. Centro de Solos e Recursos Ambientais; Ambrosano, Glaucia Maria Bovi [Universidade Estadual de Campinas (UNICAMP), Piracicaba, SP (Brazil). Fac. de Odontologia. Dept. de Odontologia Social], Email: ambrosano@apta.sp.gov.br; Schammass, Eliana Aparecida [Agencia Paulista de Tecnologia dos Agronegocios (APTA/IZ), Nova Odessa, SP (Brazil). Inst. de Zootecnia; Muraoka, Takashi; Trivelin, Paulo Cesar Ocheuze [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Ungaro, Maria Regina Goncalves [Agencia Paulista de Tecnologia dos Agronegocios (APTA/IAC), Campinas, SP (Brazil). Inst. Agronomico. Centro de Plantas Graniferas

2010-07-01

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Weed control through crop rotation and alternative management practices  

Directory of Open Access Journals (Sweden)

Full Text Available Economic as well as agricultural and socio-political changes have an impact on crop management and thus also on crop rotation design and the related effects on the weed flora. Likewise other changes in cultivation such as reduced tillage practices, earlier sowing date, etc. cause an increase in weed infestation resp. an increased use of herbicides and if so contribute to herbicide resistance. The positive effects of crop rotation, but also of alternative management practices such as choice of varieties, catch crops, mixed cropping, green chop, and the share of predators, as well as methods of direct non-chemical weed control are presented and discussed for both, conventional and organic farming. If alternative management methods should be more practiced, especially trade-offs need to be broken, or incentives be offered.

Böhm, Herwart

2014-02-01

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Crop Sequence Economics in Dynamic Cropping Systems  

Science.gov (United States)

No-till production systems allow more intensified and diversified production in the northern Great Plains; however, this has increased the need for information on improving economic returns through crop sequence selection. Field research was conducted 6 km southwest of Mandan ND to determine the inf...

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Cereal-forage crop rotations and irrigation treatment effect on water use efficiency and crops sustainability in Mediterranean environment  

Directory of Open Access Journals (Sweden)

Full Text Available Agricultural systems based on crop rotations favour sustainability of cultivation and productivity of the crops. Wheat-forage crops rotations (annual winter binary mixture and perennial alfalfa meadow combined with irrigation are the agronomical techniques able to better exploit the weather resources in Mediterranean environments. The experiment aimed to study the effect of 18 years of combined effect of irrigation and continuous durum wheat and wheat-forage rotations on productivities of crops and organic matter of topsoil. The experiments were established through 1991-2008 under rainfed and irrigated treatments and emphasized on the effect of irrigation and continuous wheat and wheat-forage crop rotations on water use efficiency and sustainability of organic matter. The effect of irrigation increased 49.1% and 66.9% the dry matter of mixture and meadow, respectively. Continuous wheat rotation reduced seed yield, stability of production, crude protein characteristics of kernel and soil organic matter. The yearly gain in wheat after forage crops was 0.04 t (ha·yr-1 under rainfed and 0.07 t (ha·yr-1 under irrigation treatments. The crude protein and soil organic matter of wheat rotations, compared to those of continuous wheat under rainfed and irrigated was increase in term of point percentage by 0.8 and 0.5 in crude protein and 5.1 and 4.4 in organic matter, respectively. The rotations of mixture and meadow under both irrigated treatments increased the point of percentage of organic matter over continuous wheat (9.3.and 8.5 in mixture and 12.5 and 9.5 meadow under rainfed and irrigation, respectively. Irrigation reduce the impact of weather on crop growing reducing water use efficiency (mean over rotations for dry mater production (15.5 in meadow and 17.5 in mixture [L water (kg·dry·matter-1 ] and wheat seed yield. The effect of agronomic advantages achieved by forage crops in topsoil expire its effect after three years of continuous wheat rotation.

Pasquale Martiniello

2012-01-01

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Produtividade do algodoeiro herbáceo em plantio direto no Cerrado com rotação de culturas Herbaceous cotton yield in no-till system in rainfed Savannah conditions with crop rotation  

Directory of Open Access Journals (Sweden)

Full Text Available O experimento, instalado em um Latossolo Vermelho-Amarelo muito argiloso, teve o objetivo de avaliar o efeito da rotação de culturas na produtividade do algodoeiro herbáceo (Gossypium hirsutum L. r. latifolium Hutch em plantio direto sob condições de sequeiro no Cerrado. O delineamento experimental foi de blocos casualizados com cinco tratamentos e quatro repetições. Os tratamentos consistiram das rotações soja-milheto-soja-milheto-algodoeiro; soja-amaranto-soja-nabo forrageiro-soja-algodoeiro; soja-sorgo granífero-soja-sorgo granífero-algodoeiro; soja-aveia preta-soja-aveia preta-algodoeiro e soja-soja-algodoeiro. A maior produtividade do algodoeiro foi obtida com a rotação de soja e milheto, em que houve melhor controle de plantas daninhas.The experiment was carried out in a heavy red yellow latosol and aimed at evaluating crop rotation on herbaceous cotton yields in no-till system under rainfed Savannah conditions. The experimental design used was a completely randomised blocks with five treatments: soybean-millet-soybean-millet-cotton; soybean-amaranth-soybean-forage radish-soybean-cotton; soybean-grain sorghum-soybean-grain sorghum-cotton; soybean-black rye-soybean-black rye-cotton and soybean-soybean-cotton and four replications. The highest cotton seed yield was obtained in the sequence soybean-millet-soybean-millet-cotton, in which best weed control also occurred.

José Carlos Corrêa

2004-01-01

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Produtividade do algodoeiro herbáceo em plantio direto no Cerrado com rotação de culturas / Herbaceous cotton yield in no-till system in rainfed Savannah conditions with crop rotation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O experimento, instalado em um Latossolo Vermelho-Amarelo muito argiloso, teve o objetivo de avaliar o efeito da rotação de culturas na produtividade do algodoeiro herbáceo (Gossypium hirsutum L. r. latifolium Hutch) em plantio direto sob condições de sequeiro no Cerrado. O delineamento experimental [...] foi de blocos casualizados com cinco tratamentos e quatro repetições. Os tratamentos consistiram das rotações soja-milheto-soja-milheto-algodoeiro; soja-amaranto-soja-nabo forrageiro-soja-algodoeiro; soja-sorgo granífero-soja-sorgo granífero-algodoeiro; soja-aveia preta-soja-aveia preta-algodoeiro e soja-soja-algodoeiro. A maior produtividade do algodoeiro foi obtida com a rotação de soja e milheto, em que houve melhor controle de plantas daninhas. Abstract in english The experiment was carried out in a heavy red yellow latosol and aimed at evaluating crop rotation on herbaceous cotton yields in no-till system under rainfed Savannah conditions. The experimental design used was a completely randomised blocks with five treatments: soybean-millet-soybean-millet-cott [...] on; soybean-amaranth-soybean-forage radish-soybean-cotton; soybean-grain sorghum-soybean-grain sorghum-cotton; soybean-black rye-soybean-black rye-cotton and soybean-soybean-cotton and four replications. The highest cotton seed yield was obtained in the sequence soybean-millet-soybean-millet-cotton, in which best weed control also occurred.

José Carlos, Corrêa; Ravi Datt, Sharma.

2004-01-01

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Long-term rotation and tillage effects on soil structure and crop yield  

DEFF Research Database (Denmark)

Tillage and rotation are fundamental factors influencing soil quality and thus the sustainability of cropping systems. Many studies have focused on the effects of either tillage or rotation, but few have quantified the long term integrated effects of both. We studied the issue using a 30-year old long-term rotation and tillage treatment experiment on a Canadian silt loam soil. Topsoil measurements were carried out for three different rotations: R1, (C–C–C–C) continuous corn (Zea mays L.), R6, (C–C–O(RC), B(RC)) corn, corn, oats (Avena fatua L.) and spring barley (Hordeum vulgare L.) and R8, (C–C–S–S) corn, corn, soybean (Glycine max L.), soybean. A red clover (Trifolium pretense L.) cover crop was under seeded in oats and spring barley in R6. In 2010, first year corn was grown in R6 and R8. The tillage treatments included no tillage, NT and mouldboard ploughing, MP. Topsoil structural quality was visually evaluated in early June and mid October. Minimal disturbed soil cores collected in early June were used for X-ray CT scanning and to quantify water content and porosity. Soil friability was determined on the soil samples using a drop shatter test. Crop yield was determined and correlated to the soil quality estimates. We found significant effect of both rotation and tillage on visual soil structure at both times of assessment. Poor soil structure was found for NT except when combined with a diverse crop rotation (R6). The soil core pore characteristics data also displayed a significant effect of tillage but only a weak insignificant effect of rotation. The drop shatter results were in accordance with the visual assessment data. Crop yield correlated significantly with the visual soil structure scores. We conclude that a diverse crop rotation was needed for an optimal performance of NT for the studied soil.

Munkholm, Lars Juhl; Heck, R

2013-01-01

42

Environmental enhancement using short-rotation woody crops and perennial grasses as alternative agricultural crops  

Energy Technology Data Exchange (ETDEWEB)

Short-rotation woody crops and perennial grasses are grown as biomass feedstocks for energy and fiber. When replacing traditional row crops on similar lands, these alternative crops can provide multiple environmental benefits in addition to enhancing rural economies and providing valuable resources. The DOE is supporting research to address how these crops can provide environmental benefits to soil, water, and native wildlife species in addition to providing bioenergy feedstocks. Research is underway to address the potential for biomass crops to provide soils conservation and water quality improvements in crop settings. Replacement of traditional erosive row drops with biomass crops on marginal lands and establishment of biomass plantations as filter strips adjacent to streams and wetlands are being studied. The habitat value of different crops for wildlife species is also considered. Combining findings on wildlife use of individual plantations with information on the cumulative effects of multiple plantations on wildlife populations can provide guidance for establishing and managing biomass crops to enhance biodiversity while providing feedstocks. Data from site-specific environmental studies can provide input for evaluation of the effects of large-scale plantings at both landscape and regional levels of resolution.

Tolbert, V.R. [Oak Ridge National Lab., TN (United States); Schiller, A. [Oak Ridge Inst. for Science and Education, TN (United States)

1996-10-01

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Short rotation woody crops: Using agroforestry technology for energy in the United States  

International Nuclear Information System (INIS)

Agroforestry in the United States is being primarily defined as the process of using trees in agricultural systems for conservation purposes and multiple products. The type of agroforestry most commonly practiced in many parts of the world, that is the planting of tree crops in combination with food crops or pasture, is the type least commonly practiced in the United States. One type of agroforestry technique, which is beginning now and anticipated to expand to several million acres in the United States, is the planting of short-rotation woody crops (SRWCs) primarily to provide fiber and fuel. Research on SRWC's and environmental concerns are described

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Tracking nitrogen losses in a greenhouse crop rotation experiment in North China using the EU-RotateN simulation model  

International Nuclear Information System (INIS)

Vegetable production in China is associated with high inputs of nitrogen, posing a risk of losses to the environment. Organic matter mineralisation is a considerable source of nitrogen (N) which is hard to quantify. In a two-year greenhouse cucumber experiment with different N treatments in North China, non-observed pathways of the N cycle were estimated using the EU-RotateN simulation model. EU-RotateN was calibrated against crop dry matter and soil moisture data to predict crop N uptake, soil mineral N contents, N mineralisation and N loss. Crop N uptake (Modelling Efficiencies (ME) between 0.80 and 0.92) and soil mineral N contents in different soil layers (ME between 0.24 and 0.74) were satisfactorily simulated by the model for all N treatments except for the traditional N management. The model predicted high N mineralisation rates and N leaching losses, suggesting that previously published estimates of N leaching for these production systems strongly underestimated the mineralisation of N from organic matter. - The EU-RotateN model can satisfactorily simulate crop N uptake and Nmin dynamics in a typical greenhouse cucumber production system of North China

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Nuclear methods for plant nutrient and water balance studies. Results of an FAO/IAEA regional technical co-operation programme on nuclear methods for plant nutrients and water balance studies under legume-cereal or fallow-cereal crop rotation systems implemented for Middle Eastern countries (1991-1994)  

International Nuclear Information System (INIS)

In semi-arid Middle Eastern countries, the increasing demand for food and other agricultural products calls for urgent measures to increase plant nutrient availability and water use efficiency. Water and plant nutrients are the two main crop yield limiting factors in these regions. Improved methods must be developed to sustain crop productivity of the legume-cereal rotation systems. It has been recognized for years that the growth of leguminous crops can improve the N status of the soil through biological nitrogen fixation (BNF). The conditions to improve the efficiency of the fixation process should be further investigated in order to fully benefit from this cheap N source. The BNF process is especially interesting for those areas facing limited fertilizer N availability or where the price of the fertilizers is too high for the farmers. In view of sustainable productivity, even with adequate supply of nutrients (nitrogen) and water, crop rotations have been promoted for years. However, the best rotation, taking into account the available nutrients and water in a specific place, is not always known. Furthermore, if a leguminous crop can be incorporated into a crop rotation system, free N is provided for this crop and some of it can serve as residual N for the next crop in the rotation. The use of 15N technology provides a unique tool to separately study the behaviour of fertilizer N as well as soil N. In addition, the quantification of residual fertilizer N is possible, as well as the quantification of BNF. Refs, figs, tabs

46

Soil carbon and crop yields affected by irrigation, tillage, crop rotation, and nitrogen fertilization  

Science.gov (United States)

Information on management practices is needed to increase surface residue and soil C sequestration to obtain farm C credit. The effects of irrigation, tillage, cropping system, and N fertilization were evaluated on the amount of crop biomass (stems and leaves) returned to the soil, surface residue C...

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CONVERSÃO E BALANÇO ENERGÉTICO DE SISTEMAS DE SUCESSÃO E DE ROTAÇÃO DE CULTURAS / ENERGY CONVERSION AND BALANCE OF CROP SUCCESSION AND ROTATION SYSTEMS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Do ponto de vista calórico, existem poucos trabalhos no Brasil estimando a conversão e o balanço energético. Neste estudo, avaliaram-se a conversão e o balanço energético de sete sistemas de rotação de culturas durante nove anos (1987 a 1995), em Passo Fundo, RS. Os sistemas foram constituídos por: [...] sistema I (trigo/soja); sistema II (trigo/soja, de 1987 a 1989, e trigo/soja e ervilhaca/ milho ou sorgo, de 1990 a 1995); sistema III (trigo/soja, aveia preta ou aveia branca/soja e ervilhaca/milho ou sorgo); sistema IV (trigo/soja, aveia branca/soja, linho/soja e ervilhaca/milho, de 1987 a 1989, e trigo/soja, girassol ou aveia preta/soja, aveia branca/soja e ervilhaca/milho ou sorgo, de 1990 a 1995); sistema V (trigo/soja, trigo/soja, aveia preta ou aveia branca/soja e ervilhaca/milho ou sorgo); sistema VI (trigo/ soja, trigo/soja, aveia branca/soja, linho/soja e ervilhaca/milho, de 1987 a 1989, e trigo/soja, trigo/soja, girassol ou aveia preta/soja, aveia branca/soja e ervilhaca/milho ou sorgo, de 1990 a 1995); e VII (pousio de inverno/soja, de 1990 a 1995). No período agrícola de 1987 a 1989, não houve diferenças significativas entre os sistemas de rotação de culturas, em relação à conversão energética e ao balanço energético. Na média do período de 1990 a 1995, o sistema II (8,58) apresentou índice de conversão energética maior do que o do sistema I (5,61), e os demais sistemas não diferiram significativamente entre si. No mesmo período, o balanço energético para os sistemas II (20.938Mcal/ha), III (19.239Mcal/ha), IV (18.618Mcal/ha), V (19.646kg/Mcal) e VI (18.702Mcal/ha) foi superior ao do sistema VII (10.279Mcal/ha). A rotação de culturas foi mais eficiente, sem aumentar o consumo de energia não renovável. Abstract in english Energy conversion and balance of seven crop rotation systems for wheat were assessed from 1987 to 1995, in Passo Fundo, RS, Brazil. The following systems were evaluated: system I (wheat/soybean); system II (wheat/soybean, from 1987 to 1989, and wheat/soybean and common vetch/corn or sorghum, from 19 [...] 90 to 1995); system III (wheat/soybean, black oats or white oats/soybean, and common vetch/corn or sorghum); system IV (wheat/soybean, white oats/soybean, flax/soybean, and common vetch/corn, from 1987 to 1989, and wheat/soybean, sunflower or black oats/soybean, white oats/soybean, and common vetch/corn or sorghum, from 1990 to 1995); system V (wheat/soybean, wheat/soybean, black oats or white oats/soybean, and common vetch/corn or sorghum); system VI (wheat/soybean, wheat/soybean, white oats/soybean, flax/soybean, and common vetch/corn, from 1987 to 1989, and wheat/soybean, wheat/soybean, sunflower or black oats/soybean, white oats/soybean, and common vetch/corn or sorghum, from 1990 to 1995); and VII (winter fallow/soybean, from 1990 to 1995). On the average from1987 to 1989, no significant differences among rotation systems were observed for energy conversion and energy balance rates. From 1990 to 1995, system II (8.58) showed greater energy conversion index than system I (5.61), and the remaining systems did not differ significantly among themselves. From 1990 to 1995, systems II (20,938Mcal/ha), III (19,239Mcal/ha), IV (18,618Mcal/ha), V (19.646Mcal/ha), and VI (18,702Mcal/ha) showed greater energy balance, as compared to system VII (10.279kg/Mcal).

Henrique Pereira dos, Santos; Julio Cesar Barreneche, Lhamby; João Carlos, Ignaczak; Guido André, Schneider.

2001-04-01

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Effects of Potato-Cotton Cropping Systems and Nematicides on Plant-Parasitic Nematodes and Crop Yields  

OpenAIRE

Belonolaimus longicaudatus has been reported as damaging both potato (Solanum tuberosum) and cotton (Gossypium hirsutum). These crops are not normally grown in cropping systems together in areas where the soil is infested with B. longicaudatus. During the 1990s cotton was grown in a potato production region that was a suitable habitat for B. longicaudatus. It was not known how integrating the production of these two crops by rotation or double-cropping would affect the population densities of...

Crow, W. T.; Weingartner, D. P.; Dickson, D. W.

2000-01-01

49

INFLUÊNCIA DE CULTURAS DE INVERNO SOBRE O RENDIMENTO DE GRÃOS DE SOJA CULTIVADA EM SISTEMAS DE ROTAÇÃO DE CULTURAS / INFLUENCE OF WINTER CROPS ON SOYBEAN YIELD IN CROP ROTATION SYSTEMS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Durante nove anos, avaliou-se o efeito de diferentes culturas antecessoras sobre o rendimento de grãos e sobre a estatura de plantas de soja, na EMBRAPA-Centro Nacional de Pesquisa de Trigo (CNPT), em Passo Fundo, RS. Os tratamentos consistiram em sete sistemas de rotação de culturas, e a soja foi s [...] emeada em sucessão à aveia branca, à aveia preta, ao linho e ao trigo. Em 1990, foram adicionadas duas parcelas, uma para completar o sistema II e outra para pousio de inverno antecedendo a soja (sistema VII). As culturas de inverno foram estabelecidas com preparo convencional de solo, e as de verão, em plantio direto. O delineamento experimental foi blocos ao acaso, com três repetições, e parcelas com área útil de 30m². A soja cultivada após linho, na média do período de 1987 a 1989, nos sistemas IV e VI, apresentou menor estatura de plantas e menor rendimento de grãos. Nos períodos de 1990 a 1992 e de 1993 a 1995, não houve diferenças significativas entre tipo de cultura antecessora e rendimento de grãos. A soja cultivada após aveia branca, após aveia preta ou após trigo pode ser incluída, sem prejuízo, nos diferentes sistemas estudados. Abstract in english Different preceding crops on the yield and height of soybean plants was assessed during nine years at EMBRAPA-Centro Nacional de Pesquisa de Trigo (CNPT), in Passo Fundo, RS, Brazil. The treatments consisted of seven crop systems, and soybean was sown in succession to white oat, black oat, flax, and [...] wheat. Two plots were added in 1990; one to complement system II and the other as winter fallow preceding soybean (system VII). Winter crops were set up using conventional soil preparation, and summer crops were sown under no-tillage. An experimental design of blocks at random, with three replications and plots totalling 30m², was used. The grown soybean after flax, in the mean of the period 1987 to 1989, in systems IV and VI showed lower plant on height and lower yield. No significant differences were found on the evoluated preceding crops on the yield over the periods 1990 to 1992 and 1993 to 1995. The grown soybean after white oat, black oat or wheat may be included in the different systems studied without any adverse effect.

Henrique Pereira dos, Santos; Julio Cesar Barreneche, Lhamby.

2001-02-01

50

Carbon storage and recycling in short-rotation energy crops  

International Nuclear Information System (INIS)

Short-rotation energy crops can play a significant role in storing carbon compared to the agricultural land uses they would displace. However, the benefits from these plantations in avoiding further use of fossil fuels and in taking pressure off native forests for energy uses provides longer term carbon benefits than the plantation carbon sequestration itself. The fast growth and harvest frequency of plantations tends to limit the amount of above- and below-ground carbon storage in them. The primary components of plantation carbon sequestering compared to sustained agricultural practices involve above ground wood, possible increased soil carbon, litter layer formation, and increased root biomass. On the average, short-rotation plantations in total may increase carbon inventories by about 10 to 40 tonnes per hectare over about a 20 to 50 year period when displacing cropland. This is about doubling in storage over cropland and about one-half the storage in human-impacted forests. The sequestration benefit of wood energy crops over cropland would be negated in about 75 to 100 years by the use of fossil fuels to tend the plantations and handle biomass. Plantation interactions with other land uses and total landscape carbon inventory is important in assessing the relative role plantations play in terestrial and atmospheric carbon dynamics. It is speculated that plantations, when viewed in this context, could generate a global levelling of net carbon emissions for approximaling of net carbon emissions for approximately 10 to 20 years. 16 refs., 7 figs

51

Carbon storage and recycling in short-rotation energy crops  

International Nuclear Information System (INIS)

Short-rotation energy crops can play a significant role in storing carbon compared to the agricultural land uses they would displace. However, the benefits from these plantations in avoiding further use of fossil fuel and in taking pressure off of native forests for energy uses provides longer term carbon benetfits than the plantation carbon sequestration itself. The fast growth and harvest frequency of plantations tends to limit the amount of above and below-ground carbon storage in them. The primary components of plantation carbon sequestering compared to sustained agricultural practices involve above-ground wood, possible increased soil carbon, litter layer formation, and increased root biomass. On the average, short-rotation plantations in total may increase carbon inventories by about 30 to 40 tonnes per hectare over about a 20- to 56-year period when displacing cropland. This is about doubling in storage over cropland and about one-half the storage in human-impacted forests. The sequestration benefit of wood energy crops over cropland would be negated in about 75 to 100 years by the use of fossil fuels to tend the plantations and handle biomass. Plantation interactions with other land uses and total landscape carbon inventory is important in assessing the relative role plantations play in terrestrial and atmospheric carbon dynamics. It is speculated that plantations, when viewed in this context. could trencrate a global leveling of net carbon emissions for approximately 10 to 20 years

52

Will breeding for nitrogen use efficient crops lead to nitrogen use efficient cropping systems? : A simulation study of GXEXM interactions  

DEFF Research Database (Denmark)

The benefits of improving nitrogen use efficiency (NUE) in crops are typically studied through the performance of the individual crop. However, in order to increase yields in a sustainable way, improving NUE of the cropping systems must be the aim. We did a model simulation study to investigate how improvement of NUE traits of individual crops affects the succeeding crops and the NUE of the crop rotation. Based on experimental results parameterization was altered for different types of improved NUE in the EU-Rotate_N model, e.g. through higher N harvest index, reduced litter loss or improved root depth penetration rate. The different ways of improving NUE have different effects on the cropping system, affecting either N uptake, the ability of the crop to hold on to N already taken up, or the fraction of crop N being harvested. Due to the different modes of action, the model simulations show that these changes in NUE traits will also have different effects on N leaching loss and on N availability and N loss inthe following years. Simulations also show that the effect of genotypes with improved NUE depend on environment and crop management. This is true for the improved crop itself and when its effect is analyzed for the whole cropping system. The environmental conditions, crop choices and management will all affect the fate of the N left in the soil, and whether this will contribute mainly to leaching loss or be used for production in later crops. As an example, increasing pre-crop fertilization was shown to affect the leaching after the following oilseed rape crop with up to 50 kg N ha?1 taken up before it was lost to the environment when pre-crop fertilization as well as root depth penetration rate was high. All in all, the simulations illustrate the concept of NUE as the result of interactions between genotype, environment and crop management (G×E×M).

DresbØll, Dorte Bodin; Thorup-Kristensen, Kristian

2014-01-01

53

Can non-inversion tillage and straw retainment reduce N leaching in cereal based crop rotations?  

DEFF Research Database (Denmark)

Finding ways of reducing nitrate leaching in Northern Europe has become an extremely important task, especially under the projected climate changes that are expected to exacerbate the problem. To this end, two field experiments were established under temperate coastal climate conditions to evaluate the effect of tillage, straw retainment and cropping sequences, including cover crops, on nitrate leaching. The experiments were established in autumn 2002 on a loamy sand with 92 g clay kg-1 and a sandy loam with 147 g clay kg-1. The tillage treatments were stubble cultivation to 8-10 cm or 3-4 cm, direct drilling, or ploughing to 20 cm. The hypothesis was that (i) decreasing soil tillage intensity would decrease leaching compared to ploughing, (ii) leaving straw in the field would decrease leaching compared to removing straw, and (iii) a spring/winter crop rotation with catch crops would be more efficient in reducing nitrate leaching than a winter crop rotation. Overall, we were not able to confirm the three hypotheses. The effect of soil tillage on leaching might be blurred because the studied crop rotations had a high proportion of winter crops and because catch crops were grown whenever the alternative would have been bare soil in autumn and winter. The spring/winter crop rotation with catch crops was not found to be more efficient in reducing nitrate leaching than the winter crop rotation. In contrast, in a single year the winter crop rotation showed significantly lower leaching than the spring/winter crop rotations, probably due to the spring/winter crop rotation including peas, which may be considered a high-risk crop. Our study highlights that management practices that improve biomass production throughout the year are crucial in order to tighten the nitrogen cycle and thereby reduce nitrate leaching.

Hansen, Elly MØller; Munkholm, Lars Juhl

2010-01-01

54

Rotação de culturas para trigo, após quatro anos: efeitos na fertilidade do solo em plantio direto Crop rotation systems for wheat, after four years: effects on soil fertility under no-tillage  

Directory of Open Access Journals (Sweden)

Full Text Available A fertilidade do solo foi avaliada, após quatro anos (1990 a 1994, num latossolo bruno álico, em Guarapuava, PR, Brasil, em quatro sistemas de rotação de culturas para trigo: sistema I (trigo/soja; sistema II (trigo/soja e aveia branca/soja; sistema III (trigo/soja, ervilhaca/ milho e aveia branca/soja; e sistema IV (trigo/soja, aveia branca/soja, cevada/soja e ervilhaca/ milho. As culturas, tanto de inverno como de verão, foram estabelecidas sob plantio direto. O delineamento experimental foi de blocos ao acaso com quatro repetições. Através de contrastes, foram comparados os sistemas e as profundidades de amostragem de solo. Em todos os sistemas de rotação de culturas, na camada de solo 0 a 5cm, observaram-se valores maiores de pH e de Ca+Mg e menores de Al (com exceção do sistema III, em relação à camada 15 a 20cm. Houve elevação dos teores de Ca+Mg, de K e de P na camada de solo com a maior concentração de raízes (0 a 10cm. Os valores de matéria orgânica do solo decresceram progressivamente da camada 0 a 5cm para a camada 15 a 20cm.Soil fertility parameters were evaluated after four years (1990 to 1994 on a alic dusky latosol located in Guarapuava, Paraná, Brazil, under four wheat crop rotation systems as follows: system I (wheat/soybean; system II (wheat/soybean and white oats/soybean; system III (wheat/soybean, common vetch/corn, and white oats/soybean; and system IV (wheat/soybean, white oats/soybean, barley/soybean and common vetch/cor. Both winter and summer crops were seeded under no tillage. A randomized complete block design, with four replications, was used. Crop systems and soil samples at different depths were compared using the contrast procedure. All crop rotation systems, in the 0 to 5cm soil layer, higher values were observed for pH in water and Ca+Mg and lower contents for Al (except system III, as compared to the 15 to 20cm layer. Raising in Ca+Mg, K, and P levels occurred in the soil layer with the greatest root concentration (0 to 10cm. The soil organic matter contents decreased with depth from 0-5cm to 15-20cm.

Henrique Pereira dos Santos

1999-06-01

55

Carbon stock and its compartments in a subtropical oxisol under long-term tillage and crop rotation systems Estoque e compartimentos de carbono em um latossolo vermelho subtropical sob diferentes sistemas de longo prazo de preparo e rotação de culturas  

Directory of Open Access Journals (Sweden)

Full Text Available Soil organic matter (SOM plays a crucial role in soil quality and can act as an atmospheric C-CO2 sink under conservationist management systems. This study aimed to evaluate the long-term effects (19 years of tillage (CT-conventional tillage and NT-no tillage and crop rotations (R0-monoculture system, R1-winter crop rotation, and R2- intensive crop rotation on total, particulate and mineral-associated organic carbon (C stocks of an originally degraded Red Oxisol in Cruz Alta, RS, Southern Brazil. The climate is humid subtropical Cfa 2a (Köppen classification, the mean annual precipitation 1,774 mm and mean annual temperature 19.2 ºC. The plots were divided into four segments, of which each was sampled in the layers 0-0.05, 0.05-0.10, 0.10-0.20, and 0.20-0.30 m. Sampling was performed manually by opening small trenches. The SOM pools were determined by physical fractionation. Soil C stocks had a linear relationship with annual crop C inputs, regardless of the tillage systems. Thus, soil disturbance had a minor effect on SOM turnover. In the 0-0.30 m layer, soil C sequestration ranged from 0 to 0.51 Mg ha-1 yr-1, using the CT R0 treatment as base-line; crop rotation systems had more influence on soil stock C than tillage systems. The mean C sequestration rate of the cropping systems was 0.13 Mg ha-1 yr-1 higher in NT than CT. This result was associated to the higher C input by crops due to the improvement in soil quality under long-term no-tillage. The particulate C fraction was a sensitive indicator of soil management quality, while mineral-associated organic C was the main pool of atmospheric C fixed in this clayey Oxisol. The C retention in this stable SOM fraction accounts for 81 and 89 % of total C sequestration in the treatments NT R1 and NT R2, respectively, in relation to the same cropping systems under CT. The highest C management index was observed in NT R2, confirming the capacity of this soil management practice to improve the soil C stock qualitatively in relation to CT R0. The results highlighted the diversification of crop rotation with cover crops as a crucial strategy for atmospheric C-CO2 sequestration and SOM quality improvement in highly weathered subtropical Oxisols.A matéria orgânica do solo (MOS desempenha papel relevante na qualidade do solo e pode atuar como dreno de C-CO2 atmosférico em solos sob sistemas de manejo conservacionista. Este estudo foi realizado com o objetivo de investigar o efeito de longo prazo (19 anos de sistemas de preparo do solo (PC-preparo convencional e PD-plantio direto e de rotação de culturas (R0- sucessão de monoculturas, R1- rotação de culturas de inverno e R2- rotação intensiva de culturas no estoque de carbono (C orgânico total, particulado e associado a minerais de um Latossolo Vermelho, originalmente degradado, do Sul do Brasil. O clima é subtropical úmido Cfa 2, segundo a classificação de Köppen, com média anual de precipitação pluvial de 1.774 mm e média anual de temperatura de 19,2 ºC. As parcelas experimentais foram divididas em três segmentos, e em cada um destes foram coletadas amostras nas profundidades de 0-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,30 m. As amostras foram coletadas por meio da abertura manual de pequenas trincheiras. O estoque de C no solo apresentou relação linear com o aporte anual de C, independentemente do sistema de preparo investigado. Assim, o preparo do solo teve pequeno efeito no incremento da taxa de decomposição da MOS. Na camada de 0-0,30 m, a taxa de sequestro de C variou de zero a 0,51 Mg ha-1 ano-1 considerando o tratamento CT R0 como referência, sendo a rotação de culturas uma estratégia mais eficiente em determinar o acúmulo de C do que os sistemas de preparo. Na média dos sistemas de cultura, uma taxa de sequestro de C de 0,13 Mg ha-1ano-1 foi observada sob PD em relação ao PC. Isso é claro? Esse resultado foi determinado pelo maior aporte de C proporcionado pela melhoria da qualidade do solo em PD adotado por longo prazo. A fração particulada de C foi um indicador eficie

Ben-Hur Costa de Campos

2011-06-01

56

Faba bean in cropping systems  

OpenAIRE

The grain legume (pulse) faba bean (Vicia faba L.) is grown world-wide as protein source for food and feed, but at the same time faba bean offers ecosystem services such as renewable inputs of nitrogen (N) into crops and soil via biological N2 fixation, and a diversification of cropping systems. Even though the global average grain yield has almost doubled during the past 50 years the total area sown to faba beans has declined by 56% over the same period. The season-to-season fluctuations in ...

Jensen, Erik Steen; Peoples, Mark B.; Hauggaard-nielsen, Henrik

2011-01-01

57

Long-Term Effects of Rotational Tillage On Visual Evaluation of Soil Structure, Soil Quality and Crop Yield  

DEFF Research Database (Denmark)

Tillage and rotation are fundamental factors influencing soil quality and thus the sustainability of cropping systems. Many studies have focused on the effects of either tillage or rotation but few have quantified long term integrated effects tillage and rotation. We studied the issue using a 30 year old long-term rotation and tillage treatment experiment on a Canadian silt loam soil. Measurements were carried out in the topsoil for three different rotations: R1 (C-C-C-C) continuous corn (Zea mays L.), R6. (C-C-O(RC), B(RC)) corn, corn, oats (Avena fatua L.) and spring barley (Hordeum vulgare L.) and R8, (C-C-S-S) corn, corn, soybean (Glycine max L.), soybean. A red clover (Trifolium pretense L.) cover crop was under seeded in oats and spring barley in R6. In 2010, first year corn was grown in R6 and R8. The tillage treatments included no tillage, NT and mouldboard plowing, MP. Topsoil structural quality was visually evaluated early June and mid October. Minimal disturbed soil cores early June and these were used for X-ray CT scanning and more traditional analysis. Soil friability was determined on the soil samples using a drop shatter test. Crop yield was determined and correlated to the soil quality estimates. We found significant effect of both rotation and tillage on visual soil structure at both times of assessment. Poor soil structure was found for NT except when combined with a versatile crop rotation (R6). The soil core pore characteristics data also displayed a significant effect of tillage but only a weak insignificant effect of rotation. The drop shatter results were in accordance with the visual assessment data. Crop yield correlated significantly with the visual soil structure scores. We conclude that a versatile crop rotation was needed for an optimal performance of NT for the studied soil.

Munkholm, Lars Juhl; Heck, Richard

58

Fate of fertilizer nitrogen in a multiple cropping system  

International Nuclear Information System (INIS)

The fate of 15N-labelled fertilizer nitrogen, applied to the maize crop only, in a multiple cropping system for two crop rotations of maize-wheat-moong, has been studied. The pattern of fertilizer uptake by this crop, the utilization of fertilizer nitrogen residue by the succeeding crops of wheat and moong, residual nitrogen in the soil, and losses due to leaching and other processes were measured. The nitrate content of tube-well waters of an agricultural farm of the Indian Agricultural Research Institute, monitored for three years (June 1975 - March 1978), varied from 5 ppm to 35 ppm. Broad conclusions based on the experimental data, for increasing the efficiency of applied nitrogen and reducing the nitrate pollution of groundwater in relation to fertilizer practices and the change in cropping pattern are discussed. (author)

59

Tracking nitrogen losses in a greenhouse crop rotation experiment in North China using the EU-Rotate_N simulation model.  

Science.gov (United States)

Vegetable production in China is associated with high inputs of nitrogen, posing a risk of losses to the environment. Organic matter mineralisation is a considerable source of nitrogen (N) which is hard to quantify. In a two-year greenhouse cucumber experiment with different N treatments in North China, non-observed pathways of the N cycle were estimated using the EU-Rotate_N simulation model. EU-Rotate_N was calibrated against crop dry matter and soil moisture data to predict crop N uptake, soil mineral N contents, N mineralisation and N loss. Crop N uptake (Modelling Efficiencies (ME) between 0.80 and 0.92) and soil mineral N contents in different soil layers (ME between 0.24 and 0.74) were satisfactorily simulated by the model for all N treatments except for the traditional N management. The model predicted high N mineralisation rates and N leaching losses, suggesting that previously published estimates of N leaching for these production systems strongly underestimated the mineralisation of N from organic matter. PMID:20227804

Guo, Ruiying; Nendel, Claas; Rahn, Clive; Jiang, Chunguang; Chen, Qing

2010-06-01

60

On the effect of crop rotation on artificially established weed species in two field experiments  

Directory of Open Access Journals (Sweden)

Full Text Available Several studies indicate links between regional occurrence of well adapted weed species and crop rotations. Monocultures or very short crop rotation, which increased in the past decades are crucial for the establishment and dispersion of problematic weed species. In this study the impact of crop rotation on the occurrence of the species Amaranthus retroflexus (L., Anchusa arvensis (L. M. Bieb., Echinochloa crus-galli (L., Galium aparine (L., Geranium pusillum (L., Sisymbrium officinale (L., Solanum nigrum (L., Stellaria media (L. Vill., Viola arvensis Murray is investigated in four crop rotations with varying potential of crop health risks. Therefore, maize (M, oilseed rape (WR and winter wheat [early sowing (WWF and late sowing (WWS] are cropped in four different rotations (M, WR – WWF, WR – M – WWS and WR – WWF – M – WWS at two study sites in Germany since year 2008 (Rostock and 2009 (Göttingen. At the start of the project selected weed species were sown into some plots in order to simulate an artificial similar weed pressure. In all plots weed species densities were counted before spraying in a standardized observation method. Analyses of four, respectively three years give evidences of crop specific effects regarding A. arvensis, E. crus-galli, G. pusillum, S. nigrum and S. media. Moreover, first effects of crop rotations on problematic weed species indicates that expanding crop rotations is a preventive tool to reduce weed densities.

Flucke, Christoph

2014-02-01

61

Cereal yield and quality as affected by N availability in organic and conventional crop rotations in Denmark  

DEFF Research Database (Denmark)

The effects of nitrogen (N) availability related to fertilizer type, catch crop management, and rotation composition on cereal yield and grain N were investigated in four organic and one conventional cropping systems in Denmark using the FASSET model. The four-year rotation studied was: spring barley–(faba bean or grass-clover)–potato–winter wheat. Experiments were done at three locations representative of the different soil types and climatic conditions in Denmark. The three organic systems that included faba bean as the N fixing crop comprised a system with manure (stored pig slurry) and undersowing catch crops (OF + C + M), a system with manure but without undersowing catch crops (OF ? C + M), and a system without manure and with catch crops (OF + C ? M). A grass-clover green manure was used as N fixing crop in the other organic system with catch crops (OG + C + M). Cuttings of grass-clover were removed from the plots and an equivalent amount of total-N in pig slurry was applied to the cropping system. Theconventional rotation included mineral fertilizer and catch crops (CF + C + F), although only non-legume catch crops were used. Measurements of cereal dry matter (DM) at harvest and of grain N contents were done in all plots. On average the FASSET model was able to predict the yield and grain N of cereals with a reasonable accuracy for the range of cropping systems and soil types studied, having a particularly good performance on winter wheat. Cereal yields were better on the more loamy soil. DM yield and grain N content were mainly influenced by the type and amount of fertilizer-N at all three locations. Although a catch crop benefit in terms of yield and grain N was observed in most of the cases, a limited N availability affected the cereal production in the four organic systems. Scenario analyses conducted with the FASSET model indicated the possibility of increasing N fertilization without significantly affecting N leaching if there is an adequate catch crop management. This would also improve yields of cereal production of organic farming in Denmark

Doltra, Jordi; Lægdsmand, Mette

2011-01-01

62

7 CFR 205.205 - Crop rotation practice standard.  

Science.gov (United States)

...PRODUCTION ACT PROVISIONS NATIONAL ORGANIC PROGRAM Organic Production and Handling Requirements...limited to sod, cover crops, green manure crops, and catch crops that...a) Maintain or improve soil organic matter content; (b)...

2010-01-01

63

PRE-PLANT CROP ROTATION AND COMPOST AMENDMENTS FOR IMPROVING RASPBERRY ESTABLISHMENT  

Science.gov (United States)

Two preplant treatments, a sorghum x sudangrass hybrid (Sudex) - rapeseed crop rotation, and a preplant compost amendment treatment, were compared to a control corn-barley rotation for alleviating replant problems on a field with a long history of perennial fruit crops. A raspberry selection trial ...

64

Atributos bioquímicos e químicos do solo rizosférico e não rizosférico de culturas em rotação no sistema de semeadura direta / Biochemical and chemical attributes of rhizospheric and non-rhizospheric soil in no till crop rotation system  

Scientific Electronic Library Online (English)

Full Text Available Sistemas autossustentáveis favorecem as populações microbianas devido à conservação e ao aumento da matéria orgânica no solo. Além disso, as plantas que fazem parte desses sistemas promovem o efeito rizosférico, por meio da zona de influência das raízes, que resulta no aumento da atividade e na modi [...] ficação da população microbiana. O objetivo deste trabalho foi avaliar o efeito da rotação de culturas de inverno sobre sequências de verão, em sistema de semeadura direta, nos atributos bioquímicos (amilase, urease, celulase e protease) e químicos (carbono orgânico total - COT, carboidratos totais e proteínas totais) em solo rizosférico (SR) e não rizosférico (SNR). Este estudo foi constituído de três culturas de inverno: milho (Zea mays L.), girassol (Helianthus anuus L.) e guandu (Cajanus cajan (L.) Millsp), que estavam em rotação sobre três sequências de verão: soja/soja (Glycine max L.), milho/milho e soja/milho, e duas posições no solo: solo aderido às raízes das plantas (SR) e solo da entrelinha de plantio (SNR). As atividades da amilase, celulase, protease e urease no SR foram 16, 85, 62 e 100 % maiores do que no SNR; para COT e proteínas totais a diferença foi de 21 %. Das culturas de inverno, o milho foi a que mais estimulou as atividades das enzimas amilase, celulase, urease e protease no SR, bem como a atividade das enzimas amilase, urease e protease no SNR. De modo geral, os teores de proteínas totais não foram influenciados pelas culturas de inverno e pelas sequências de verão; os carboidratos totais foram influenciados pelas culturas de inverno milho e girassol. Para o COT houve influência apenas da sequência de verão milho/milho. Os atributos bioquímicos e químicos avaliados neste estudo podem ser utilizados como indicadores das alterações no solo promovidas pelas culturas de inverno e pelas sequências de verão. Abstract in english Self-sustaining systems encourage microbial populations due to the conservation and improvement of organic matter in the soil. In addition, the plants constituents of these systems produce the rhizospheric effect through the influence zone of the roots, increasing activity and modifying the microbia [...] l population. The objective of this study was to evaluate the effect of winter crop rotation and summer crop sequences in a no tillage system, based on biochemical (amylase, urease, cellulase, and protease) and chemical (organic carbon, total carbohydrates, and total protein) characteristics in rhizospheric (SR) and non-rhizospheric soil (SNR). Three winter crops were studied: corn (Zea mays L.), sunflower (Helianthus anuus L.), and pigeon pea (Cajanus cajan (L.) Millsp), in rotation with three summer sequences: soybean/soybean (Glycine max L.), corn/corn, and soybean/corn. Samples were taken from soil adhering to the plant roots (SR) and from in-between the rows (SNR). The activities of amylase, cellulase, protease, and urease in SR were 16, 85, 62, and 100 % higher, respectively, than in SNR. For total organic carbon and total protein, the difference was 21 %. Of the winter crops, corn stimulated higher amylase, cellulase, protease, and urease activity in SR, as well as amylase, protease, and urease activity in SNR. The winter crops and the summer sequences did not affect total protein levels. The total carbohydrates were influenced by winter corn and sunflower crops. Only the summer corn/corn sequence influenced total organic carbon. The biochemical and chemical properties analyzed in this study can be used as indicators of changes in soil caused by winter crops and summer sequences.

Meire Aparecida Silvestrini, Cordeiro; José Eduardo, Corá; Ely, Nahas.

1794-18-01

65

Rotating Aperture System  

Science.gov (United States)

A rotating aperture system includes a low-pressure vacuum pumping stage with apertures for passage of a deuterium beam. A stator assembly includes holes for passage of the beam. The rotor assembly includes a shaft connected to a deuterium gas cell or a crossflow venturi that has a single aperture on each side that together align with holes every rotation. The rotating apertures are synchronized with the firing of the deuterium beam such that the beam fires through a clear aperture and passes into the Xe gas beam stop. Portions of the rotor are lapped into the stator to improve the sealing surfaces, to prevent rapid escape of the deuterium gas from the gas cell.

Rusnak, Brian (Livermore, CA); Hall, James M. (Livermore, CA); Shen, Stewart (Danville, CA); Wood, Richard L. (Santa Fe, NM)

2005-01-18

66

Modeling the potential benefits of catch-crop introduction in fodder crop rotations in a Western Europe landscape.  

Science.gov (United States)

Among possible mitigation options to reduce agricultural-borne nitrate fluxes to water bodies, introduction of catch crop before spring crops is acknowledged as a cost-efficient solution at the plot scale, but it was rarely assessed at the catchment level. This study aims to evaluate a set of catch crop implantation scenarios and their consequences in a coastal catchment prone to eutrophication. The objectives are (i) to discuss the potential benefits of catch crop introduction taking into account the limitations due to the physiographic and agricultural context of the area (ii) to propose a multicriteria classification of these scenarios as a basis for discussion with stakeholders. We used the distributed agro-hydrological model TNT2 to simulate 25 scenarios of catch crop management, differing in length of catch crop growing period, place in the crop rotation and residue management. The scenarios were classified considering the variations in main crop yields and either nitrogen fluxes in stream or the global nitrogen mass balance at the catchment level. The simulations showed that in the catchment studied, little improvement can be expected from increasing the catch crop surface. Catch crop cultivation was always beneficial to reduce nitrogen losses, but led to adverse effects on main crop yields in some cases. Among the scenarios involving additional catch crop surface, introducing catch crop between two winter cereals appeared as the most promising. The classification of scenarios depended on the chosen criteria: when considering only the reduction of nitrogen fluxes in streams, exporting catch crop residues was the most efficient while when considering the global nitrogen mass balance, soil incorporation of catch crop residues was the most beneficial. This work highlights the interest, while using integrated models, of assessing simulated scenarios with multicriteria approach to provide stakeholder with a picture as complete as possible of the consequences of prospective policies. PMID:22944220

Moreau, P; Ruiz, L; Raimbault, T; Vertès, F; Cordier, M O; Gascuel-Odoux, C; Masson, V; Salmon-Monviola, J; Durand, P

2012-10-15

67

THE NUTRIENTS BALANCE OF CROP ROTATION AS AN INDICATOR OF SUSTAINABLE FARMING ON ARABLE LAND  

Directory of Open Access Journals (Sweden)

Full Text Available The nutrient balance of five crop rotation systems under conventional and minimal tillage with interaction of different fertilization treatments was investigated at the experimental station of Slovak Agricultural University in Nitra Dolná Malanta, during 2004-2005. The five-field crop rotation of maize (Zea mays L. - winter wheat (Triticum aestivum L. - spring barley (Hordeum vulgare L. underseeded with red clover - red clover (Trifolium pratense - common pea (Pisum sativum L. and mustard as catch crop was used. The most serious deficit of nitrogen (- 62.2 kg.ha-1.yr-1, phosphorus (- 24.0 kg.ha-1.yr-1 and potassium (- 89.2 kg.ha-1.yr-1 was on control treatments. Deficit of nitrogen was also found-out in treatments with mineral fertilizers application. However higher deficit of nitrogen (- 25.4 kg.ha-1.yr- 1 was registered under conventional tillage. In treatment fertilized with mineral fertilizers together with by - product of pre - crop incorporation into soil (PZ, small balance surplus of nitrogen (8 kg.ha-1.yr-1 - B1, 11.5 kg. ha-1.yr-1 - B2, respectively was calculated. The positive balance of phosphorus achieved in treatments with into soil incorporated by - products of pre - crops (in both systems of soil cultivation amounting value of 3.9 kg.ha-1.yr-1 can contribute to good supply of phosphorous in soil. The negative balance of potassium fluctuating from - 89.2 kg.ha-1.yr-1 (control treatment to - 22 kg.ha-1.yr-1 (PZ is acceptable owing to high content of available potassium in soil of experimental stand.

Eva Haná?ková

2009-03-01

68

Soil properties, crop production and greenhouse gas emissions in organic and conventional cropping systems  

DEFF Research Database (Denmark)

Organic and conventional farming practices differ in the use of several management strategies, including use of catch crops, green manure, and fertilization, which may influence soil properties, greenhouse gas emissions and productivity of agroecosystems. An 11-yr-old field experiment on a sandy loam soil in Denmark was used to compare several crop rotations with respect to a range of physical, chemical and biological characteristics related to carbon (C) and nitrogen (N) flows. Four organic rotations and an inorganic fertilizer-based system were selected to evaluate effects of fertilizer type, catch crops, of grass-clover used as green manure, and of animal manure application. Soil was sampled from winter wheat and spring barley plots on 19 September 2007, 14 April 2008 and 22 September 2008, i.e. before, during, and after the growth season. The soils were analyzed for multiple attributes: total soil organic carbon (SOC), total N, microbial biomass N (MBN), potentially mineralizable N (PMN), and levels of potential ammonium oxidation (PAO) and denitrifying enzyme activity (DEA). In situ measurements of soil heterotrophic carbon dioxide (CO2) respiration and nitrous oxide emissions were conducted in plots with winter wheat. In April 2008, prior to field operations, intact soil cores were collected at two depths (0–5 and 5–10 cm) in plots under winter wheat. Water retention characteristics of each core were determined and used to calculate relative gas diffusivity (DP/Do). Finally, crop growth was monitored and grain yields measured at harvest maturity. The different management strategies between 1997 and 2007 led to soil carbon inputs that were on average 18–68% and 32–91% higher in the organic than inorganic fertilizer-based rotations for the sampled winter wheat and spring barley crops, respectively. Nevertheless, SOC levels in 2008 were similar across systems. The cumulative soil respiration for the period February to August 2008 ranged between 2 and 3 t CO2–C ha?1 and was correlated (r = 0.95) with average C inputs. In the organic cropping systems, pig slurry application and inclusion of catch crops generally increased soil respiration, PMN and PAO. At field capacity, relative gas diffusivity at 0–5 cm depth was >50% higher in the organic than the inorganic fertilizer-based system (P < 0.05). Crop yields in 2008 were generally lower in the low-input organic rotations than in the high-input inorganic fertilizer-based system; only spring barley in rotations with pig slurry application and incorporation of a catch crop prior to sowing obtained grain yields similar to levels achieved in the system where inorganic fertilizer was applied. These results suggest that within organic cropping systems, both microbial activity and crop yields could be enhanced through inclusion of catch crops. However, the timing of catch crop incorporation is critical.

Chirinda, Ngonidzashe; Olesen, JØrgen E

2010-01-01

69

Nitrate leaching from organic arable crop rotations is mostly determined by autumn field management  

DEFF Research Database (Denmark)

Two main challenges facing organic arable farming are the supply of nitrogen (N) to the crop and the control of perennial weeds. Nitrate leaching from different organic arable crop rotations was investigated over three consecutive four-year crop rotations in a field experiment at three locations in Denmark (12 years in total). The experimental treatments were: (i) crop rotation, (ii) catch crop and (iii) animal manure. Nitrate leaching was estimated from measured soil nitrate concentration in ceramic suction cells and modelled drainage. There were significant effects on annual N leaching of location (coarse sand > loamy sand > sandy loam) and catch crops (without > with). Including a grass-clover green manure on 25% of the area did not increase N leaching compared with crop rotations without green manure. Also the application of animal manure did not influence N leaching, probably because even in the manured treatments the application rate was lower than crop demand. The results identify management of crop and soil during autumn as the main determinant of N leaching. Nitrate leaching was lowest for a catch crop soil cover during autumn and winter (avg. 20 kg N ha?1), a soil cover of weeds/volunteers had on avg. 30 kg N ha?1, and the largest N leaching losses were found after stubble cultivation (avg. 55 kg N ha?1). The N leaching losses increased with increasing number of autumn soil cultivations

Askegaard, M; Olesen, JØrgen E

2011-01-01

70

Biomassa, atividade microbiana e FMA em rotação cultural milho/feijão-de-corda utilizando-se águas salinas / Biomass, microbial activity and AMF in crop rotation system of maize/cowpea using saline water  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar a influência da irrigação com água de alta e baixa salinidade sobre variáveis microbiológicas do solo em área submetida à rotação de cultura entre milho (Zea Mays L.) e feijão-de-corda (Vigna unguiculata L.). A área destinada ao experimento foi dividida em duas [...] subáreas, sendo realizados quatro cultivos: dois cultivos irrigados na estação seca e dois de sequeiro na estação chuvosa. O estudo foi conduzido em campo, utilizando-se o delineamento em blocos ao acaso, com cinco repetições. Nos cultivos irrigados foram usadas água com as seguintes condutividades elétricas (CEa): 0,8; 2,2; 3,6 e 5,0 dS m-1. Os cultivos de sequeiro foram realizados nas mesmas parcelas que foram cultivadas na estação seca, as quais permaneceram demarcadas e identificadas. No início e ao final de cada cultivo, foram coletadas amostras em duas subáreas na região radicular das plantas, no terço médio da fileira central de cada parcela. O aumento da salinidade da água de irrigação promoveu aumento do número total de esporos de fungos micorrízicos arbusculares FMA e reduziu a respiração basal do solo, o carbono da biomassa e o coeficiente metabólico microbiano (qCO2), principalmente na área cultivada com feijão-de-corda. O gênero Glomus respondeu por mais de 70% dos esporos totais encontrados, sendo que essa percentagem aumentou nos tratamentos com maior salinidade nos cultivos da estação seca. Os dados não evidenciaram qualquer efeito negativo da salinidade residual sobre as variáveis microbiológicas avaliadas, em função da irrigação com água salina durante os cultivos da estação seca. Abstract in english This work carred out the influence of irrigation with water of high and low salinity on soil microbial variables in area under the crop rotation between maize (Zea Mays L.) and cowpea (Vigna unguiculata L.). The area for the experiment was divided into two sub areas being made four crops, two crops [...] irrigated in the dry season and two dry in the rainy season. The study was conducted under field conditions using a randomized block design with five replications. In irrigated crops were used the following water with electrical conductivity (ECw): 0.8; 2.2; 3.6 and 5.0 dS m-1. The rainfed crops were conducted on the same plots that were cultivated during the dry season, which remained demarcated and identified. At the beginning and end of each crop were collected samples in two subareas in the region of root system plant, in the middle third of the central row of each plot. Increasing of salinity in irrigation water led to increase in the total number of spores and reduced soil basal respiration, biomass carbon and microbial metabolic coefficient (qCO2), mainly in the area cultivated with cowpea. The genus Glomus accounted for more than 70% of total spores found, and this percentage increased in treatments with high salinity in dry season crops. The data reveal no residual negative effect of salinity on the microbial variables assessed in function irrigation with saline water during the dry season crops.

Maria Eloneide de Jesus, Bezerra; Claudivan Feitosa de, Lacerda; Geocleber Gomes de, Sousa; Vânia Felipe Freire, Gomes; Paulo Furtado, Mendes Filho.

2010-12-01

71

Effectiveness of the GAEC standard of cross compliance Crop rotations in maintaining organic matter levels in soils  

Directory of Open Access Journals (Sweden)

Full Text Available Our study was conducted in the framework of EFFICOND project, with the aim of evaluating the environmental effectiveness of GAEC (Good Agricultural and Environmental Conditions standards with particular focus to the maintenance of soil organic matter (SOM levels through the appropriate crop rotation. The study analyzed the effect of crop rotation on the build-up of soil organic matter in three different areas of Italy, located in the North (Lodi, Centre (Fagna, Firenze and South (Foggia of Italy, characterized by different climate, soil, and cropping systems. In the two experiments conducted in the South of Italy, in a dry Mediterranean climate, the stock of C was kept steady in most of the rotations compared with the monoculture of durum wheat. In such environment, with very dry and hot summers, introducing a year of fallow seems to improve SOM content, but these data need further investigation. In the Centre of Italy (Fagna, with less extreme climate than in Foggia, the effect of rotation compared to the monoculture of maize is negligible, but investigation on the soil organic matter composition, showed that in the rotation the SOM appeared to be more stable and, in the long term, probably more resistant to degradation. Eventually, experiments conducted in the North of Italy, showed that the monoculture, despite the application of FYM (Farm Yard Manure or semi-liquid manure, led to a decrease of SOM. To an increase of the rotation complexity, corresponded an increase in the stock of C in soil. Summarizing, results showed that crop rotation could guarantee the maintenance of SOM level, given that the input of C to the soil is maintained at a good level or, in other word, that productivity of the system is high. Other practices such as conservation tillage, appropriate management of residues, and manure application could enhance the positive effect of rotations. Moreover, preliminary investigation of soil microbial diversity, suggests the positive effect of rotations on soil biological fertility.

Roberta Farina

2011-09-01

72

Rotating shielded crane system  

International Nuclear Information System (INIS)

A rotating, radiation-shielded crane system is described comprising: a generally cylindrical, radiation-shielding wall, the top of the wall forming a first annular ledge; a second annular ledge integrally attached to the inner surface of the shielding wall; a generally cylindrical ceiling made of radiation shielding material, the ceiling including a flange portion on the top thereof and a body portion, the flange portion associated with the second annular ledge such that the ceiling is supported thereby, the volume inside the wall and the ceiling forming a test cell; a rotatable crane disposed above the ceiling such that the crane is outside of the test cell; removable access means in the ceiling for allowing the crane to access the inside of the test cell from the top of the ceiling; means for sealing the interface between the inner surface of the shielding wall and the ceiling

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Nitrogen use and efficiency in a rotation with and without incorporation of crop residues  

International Nuclear Information System (INIS)

A field experiment was conducted to study nitrogen (N) use and efficiency in a crop rotation with and without incorporation of residues under irrigated conditions. Nitrogen-15-labelled microplots were installed on a long-term experiment in which six rotations at two rates of fertilization are being examined. The rotation without incorporation of residues was maize-wheat-red clover-red clover; and the one with incorporation of residues was maize-wheat-common bean-barley. Treatments during the first growing season, when labelling maize (Experiment 1), were as follows: i) Treatment 1 (T1), determine the fate of 15N-labelled fertilizer in the rotation with incorporation of residues. During subsequent seasons, only unlabelled residues were applied to these plots; ii) T2, determine the fate of 15N-labelled residue with residues. Labelled residues were applied in the second growing season and, thereafter, unlabelled residues were used; iii) T3, determine the fate of labelled 15N fertilizer in the rotation without residue incorporation - the control treatment for maize. During the second growing season (Experiment 2), the 15N-labelled experiment was repeated and wheat (second crop in the rotation) was labelled. To label maize and wheat, 300 and 160 kg N ha-1 as 15N-enriched urea and ammonium sulphate were applied, respectively. The labelled residues of maize and wheat were applied before sowing at 8,000 and 4,0ere applied before sowing at 8,000 and 4,000 kg ha-1, respectively. The same amounts of unlabelled residues were applied afterwards where appropriate. Results from both experiments showed similar trends and did not support the hypothesis that increased inputs of carbon lead to increased retention of N in the system. Possible explanations are discussed. (author)

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Increasing cropping system diversity balances productivity, profitability and environmental health.  

Science.gov (United States)

Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and large negative impacts on the environment. We hypothesized that cropping system diversification would promote ecosystem services that would supplement, and eventually displace, synthetic external inputs used to maintain crop productivity. To test this, we conducted a field study from 2003-2011 in Iowa that included three contrasting systems varying in length of crop sequence and inputs. We compared a conventionally managed 2-yr rotation (maize-soybean) that received fertilizers and herbicides at rates comparable to those used on nearby farms with two more diverse cropping systems: a 3-yr rotation (maize-soybean-small grain + red clover) and a 4-yr rotation (maize-soybean-small grain + alfalfa-alfalfa) managed with lower synthetic N fertilizer and herbicide inputs and periodic applications of cattle manure. Grain yields, mass of harvested products, and profit in the more diverse systems were similar to, or greater than, those in the conventional system, despite reductions of agrichemical inputs. Weeds were suppressed effectively in all systems, but freshwater toxicity of the more diverse systems was two orders of magnitude lower than in the conventional system. Results of our study indicate that more diverse cropping systems can use small amounts of synthetic agrichemical inputs as powerful tools with which to tune, rather than drive, agroecosystem performance, while meeting or exceeding the performance of less diverse systems. PMID:23071739

Davis, Adam S; Hill, Jason D; Chase, Craig A; Johanns, Ann M; Liebman, Matt

2012-01-01

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Controle de plantas daninhas em feijão num sistema de rotação culturas em plantio direto Weed control in beans in a no-tillage crop rotation system  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi selecionar culturas de inverno para formação de cobertura morta que reduza a população de plantas daninhas na cultura do feijão (Phaseolus vulgaris. Ocupou-se o terreno durante o ano todo, com a sucessão, em plantio direto, de pousio ou cultura de inverno/feijão/cultura para silagem, estudando-se três modalidades de controle de plantas daninhas na cultura do feijão. A maior renda líquida acumulada após duas safras foi obtida com feijão semeado sobre palha de aveia-preta e controle de plantas daninhas com um gramicida pré-emergente, completando-se com capinas, quando necessário.This study was undertaken to select winter crops for mulching to reduce the weed infestation and to lower weed control costs in bean (Phaseolus vulgaris production. The soil was kept convered all the year under no-tillage with a sequence of a winter crop or fallow/beans/silage crop. Three weed control methods for beans were studied. After two complete crop sequences, the highest total net income was obtained with the beans directly drilled on the black oats (Avena strigosa mulching, spraying a pre-emergence grasskiller plus hoeing when needed.

Benedito N. Rodrigues

1995-01-01

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IMPACT OF GROWING CROPS AND DIFFERENT WATER LOADINGS ON THE FEATURES OF DARK CHESTNUT SOILS IN RICE ROTATIONS ??????? ????????????? ??????? ? ????????? ?????? ???????? ?? ???????? ?????-?????????? ???? ? ??????? ????????????  

Directory of Open Access Journals (Sweden)

Full Text Available The article gives a general assessment for meliorative state of soils at the rice irrigation systems in the Ros-tov region. The indices of soil salinity, alkalinity, sodicity, calium content in soil exchangeable com-plex of dark chestnut soils at different crop rotations and water loadings are afforded

Mironchenko M. S.

2013-03-01

77

Efeito de sistemas de manejo de solo e de rotação de culturas na fertilidade do solo, após vinte anos Soil tillage and crop rotation systems on soil fertility attributes after twenty years  

Directory of Open Access Journals (Sweden)

Full Text Available No Brasil, ainda são escassos os estudos disponíveis com experimentos de longa duração em sistemas de manejo de solo e de rotação de culturas. Após vinte anos (1985 a 2005, a fertilidade de solo foi avaliada, em Latossolo Vermelho distrófico típico, em Passo Fundo (RS, em quatro sistemas de manejo de solo (SMSs - 1 plantio direto (PD, 2 cultivo mínimo (CM, 3 preparo convencional de solo com arado de discos e com grade de discos (PCD e 4 preparo convencional de solo com arado de aivecas e com grade de discos (PCA - e em três sistemas de rotação de culturas (SRCs: I (trigo/soja, II (trigo/soja e ervilhaca/milho e III (trigo/soja, ervilhaca/milho e aveia branca/soja, incluindo como testemunha um fragmento adjacente de floresta subtropical (FST. O delineamento experimental foi em blocos completos ao acaso, com parcelas subdivididas e três repetições. As parcelas (4 x 90 m no total de 12, foram constituídas pelos SMSs, e as subparcelas, pelos SRCs (4 x 10 m, no total de 72. Os valores de pH, carbono, P extraível e K disponível diferiram entre os SMSs. No PD, houve acúmulo de carbono orgânico, P e K, na camada superficial. Não houve diferença do nível de matéria orgânica (MOS entre PD e FST, em todas as camadas estudadas. O nível de MOS e os teores de P e K foram mais elevados na camada 0-0,05 m, quando comparados com os observados de 0,15-0,20 m de profundidade, sob PD e nas rotações II e III. Observou-se que em FST os valores de pH, Ca, P e de K foram menores do que os dos SMSs e SRCs.Long term field studies on crop rotation and soil tillage systems under Brazilian conditions are scarce. Soil fertility characteristics were assessed after twenty years (1985 to 2005 on a typical dystrophic Red Latosol located in Passo Fundo, in Rio Grande do Sul, the southernmost state of Brazil. Four soil tillage systems (STS - 1 no-tillage, 2 minimum tillage, 3 conventional tillage using disk plow followed by disk harrow, and 4 conventional tillage using moldboard plow followed by disk harrow - and three crop rotation systems (CRS: I (wheat/soybean, II (wheat/soybean and common vetch/corn, and III (wheat/soybean, common vetch/corn, and white oat/soybean were evaluated, including as check a fragment of subtropical forest (FST. A randomized complete block design, with split-plots and three replicates, was used. The main field plots (4 x 90 m in a total of 12, were the soil tillage systems, whereas the subplots (4 x 10 m, in a total of 72 comprised the crop rotation systems. Values of soil pH, soil organic carbon, extractable P, and exchangeable K were affected by soil tillage systems (STSs. Higher levels of soil organic matter and contents of soil carbon, extractable P, and exchangeable K were observed in the 0-0,05 m layer for the no-tillage system. No statistical differences were found in soil organic matter levels between no-tillage and tropical forest, in any soil layer. Values of soil organic matter, P, and K were higher in the 0-0,05 m layer, when compared to the ones observed in the 0,15-0,20 m layer, in no-tillage and II and III CRSs. Values of pH, Ca, P, and K observed in all STSs and CRSs were higher than in the tropical forest area.

Henrique Pereira dos Santos

2008-01-01

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Soil salinization and maize and cowpea yield in the crop rotation system using saline waters Salinização do solo e produtividade de milho e feijão caupi em sistema de rotação cultural utilizando águas salinas  

Directory of Open Access Journals (Sweden)

Full Text Available The use of saline water and the reuse of drainage water for irrigation depend on long-term strategies that ensure the sustainability of socio-economic and environmental impacts of agricultural systems. In this study, it was evaluated the effects of irrigation with saline water in the dry season and fresh water in the rainy season on the soil salt accumulation yield of maize and cowpea, in a crop rotation system. The experiment was conducted in the field, using a randomized complete block design, with five replications. The first crop was installed during the dry season of 2007, with maize irrigated with water of different salinities (0.8, 2.2, 3.6 and 5.0 dS m-1. The maize plants were harvested at 90 days after sowing (DAS, and vegetative growth, dry mass of 1000 seeds and grain yield were evaluated. The same plots were utilized for the cultivation of cowpea, during the rainy season of 2008. At the end of the crop, cycle plants of this species were harvested, being evaluated the vegetative growth and plant yield. Soil samples were collected before and after maize and cowpea cultivation. The salinity of irrigation water above 2.2 dS m-1 reduced the yield of maize during the dry season. The high total rainfall during the rainy season resulted in leaching of salts accumulated during cultivation in the dry season, and eliminated the possible negative effects of salinity on cowpea plants. However, this crop showed atypical behavior with a significant proportion of vegetative mass and low pod production, which reduced the efficiency of this strategy of crop rotation under the conditions of this study.A utilização de águas salinas bem como o reúso de águas de drenagem na irrigação dependem de estratégias de longo prazo que garantam a sustentabilidade socioeconômica e ambiental dos sistemas agrícolas. Neste trabalho, avaliaram-se os efeitos da irrigação com água salina na estação seca e com água de baixa salinidade na estação chuvosa sobre o acúmulo de sais no solo e a produtividade de milho e feijão-de-corda em sistema de rotação. O experimento foi conduzido em campo, utilizando-se do delineamento em blocos ao acaso, com cinco repetições. O primeiro cultivo foi instalado durante a estação seca de 2007, com a cultura do milho irrigada com água de diferentes salinidades (0,8; 2,2; 3,6 e 5,0 dS m-1. As plantas foram coletadas aos 90 dias após a semeadura (DAS, sendo realizadas as avaliações: crescimento vegetativo, produção de grãos por planta, matéria seca de 1.000 grãos e produtividade. Durante a estação chuvosa de 2008, foi cultivado o feijão caupi nas mesmas parcelas que foram cultivadas com milho. Ao final do ciclo, as plantas foram coletadas, sendo realizadas avaliações de crescimento vegetativo e produtividade. Amostras de solo foram coletadas antes e após o cultivo do milho e ao final do cultivo com feijão caupi. A salinidade da água de irrigação acima 2,2 dS m-1 reduziu a produtividade do milho durante o período seco. Os elevados totais de precipitação pluviométrica durante a estação chuvosa proporcionaram a lixiviação dos sais acumulados durante o cultivo na estação seca e eliminaram os possíveis efeitos negativos da salinidade sobre o feijão caupi. Porém, o feijão caupi apresentou um comportamento atípico com uma expressiva proporção de massa vegetativa e baixa produção de vagens, o que reduziu a eficiência dessa estratégia de rotação de culturas, nas condições do presente estudo.

Claudivan F. Lacerda

2011-01-01

79

Soil salinization and maize and cowpea yield in the crop rotation system using saline waters / Salinização do solo e produtividade de milho e feijão caupi em sistema de rotação cultural utilizando águas salinas  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A utilização de águas salinas bem como o reúso de águas de drenagem na irrigação dependem de estratégias de longo prazo que garantam a sustentabilidade socioeconômica e ambiental dos sistemas agrícolas. Neste trabalho, avaliaram-se os efeitos da irrigação com água salina na estação seca e com água d [...] e baixa salinidade na estação chuvosa sobre o acúmulo de sais no solo e a produtividade de milho e feijão-de-corda em sistema de rotação. O experimento foi conduzido em campo, utilizando-se do delineamento em blocos ao acaso, com cinco repetições. O primeiro cultivo foi instalado durante a estação seca de 2007, com a cultura do milho irrigada com água de diferentes salinidades (0,8; 2,2; 3,6 e 5,0 dS m-1). As plantas foram coletadas aos 90 dias após a semeadura (DAS), sendo realizadas as avaliações: crescimento vegetativo, produção de grãos por planta, matéria seca de 1.000 grãos e produtividade. Durante a estação chuvosa de 2008, foi cultivado o feijão caupi nas mesmas parcelas que foram cultivadas com milho. Ao final do ciclo, as plantas foram coletadas, sendo realizadas avaliações de crescimento vegetativo e produtividade. Amostras de solo foram coletadas antes e após o cultivo do milho e ao final do cultivo com feijão caupi. A salinidade da água de irrigação acima 2,2 dS m-1 reduziu a produtividade do milho durante o período seco. Os elevados totais de precipitação pluviométrica durante a estação chuvosa proporcionaram a lixiviação dos sais acumulados durante o cultivo na estação seca e eliminaram os possíveis efeitos negativos da salinidade sobre o feijão caupi. Porém, o feijão caupi apresentou um comportamento atípico com uma expressiva proporção de massa vegetativa e baixa produção de vagens, o que reduziu a eficiência dessa estratégia de rotação de culturas, nas condições do presente estudo. Abstract in english The use of saline water and the reuse of drainage water for irrigation depend on long-term strategies that ensure the sustainability of socio-economic and environmental impacts of agricultural systems. In this study, it was evaluated the effects of irrigation with saline water in the dry season and [...] fresh water in the rainy season on the soil salt accumulation yield of maize and cowpea, in a crop rotation system. The experiment was conducted in the field, using a randomized complete block design, with five replications. The first crop was installed during the dry season of 2007, with maize irrigated with water of different salinities (0.8, 2.2, 3.6 and 5.0 dS m-1). The maize plants were harvested at 90 days after sowing (DAS), and vegetative growth, dry mass of 1000 seeds and grain yield were evaluated. The same plots were utilized for the cultivation of cowpea, during the rainy season of 2008. At the end of the crop, cycle plants of this species were harvested, being evaluated the vegetative growth and plant yield. Soil samples were collected before and after maize and cowpea cultivation. The salinity of irrigation water above 2.2 dS m-1 reduced the yield of maize during the dry season. The high total rainfall during the rainy season resulted in leaching of salts accumulated during cultivation in the dry season, and eliminated the possible negative effects of salinity on cowpea plants. However, this crop showed atypical behavior with a significant proportion of vegetative mass and low pod production, which reduced the efficiency of this strategy of crop rotation under the conditions of this study.

Claudivan F., Lacerda; Geocleber G., Sousa; Francisco L. B., Silva; Francisco V. A., Guimarães; Giovana L., Silva; Lourival F., Cavalcante.

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Environmental effects of growing short-rotation woody crops on former agricultural lands  

International Nuclear Information System (INIS)

Field-scale studies in the Southeast have been addressing the environmental effects of converting agricultural lands to biomass crop production since 1994. Erosion, surface water quality and quantity and subsurface movement of water and nutrients from woody crops, switchgrass and agricultural crops are being compared. Nutrient cycling, soil physical changes, and crop productivity are also being monitored at the three sites. Maximum sediment losses occurred in the spring and fall. Losses were greater from sweetgum planted without a cover crop than with a cover crop. Nutrient losses of N and P in runoff and subsurface water occurred primarily after spring fertilizer application. These field plot studies are serving as the basis for a water shed study initiated in 1997. Results from the two studies will be used to develop and model nutrient and hydrologic budgets for woody crop plantings to identify potential constraints to sustainable deployment of short-rotation woody crops in the southeastern United States. (author)

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Carbon stock and its compartments in a subtropical oxisol under long-term tillage and crop rotation systems / Estoque e compartimentos de carbono em um latossolo vermelho subtropical sob diferentes sistemas de longo prazo de preparo e rotação de culturas  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A matéria orgânica do solo (MOS) desempenha papel relevante na qualidade do solo e pode atuar como dreno de C-CO2 atmosférico em solos sob sistemas de manejo conservacionista. Este estudo foi realizado com o objetivo de investigar o efeito de longo prazo (19 anos) de sistemas de preparo do solo (PC- [...] preparo convencional e PD-plantio direto) e de rotação de culturas (R0- sucessão de monoculturas, R1- rotação de culturas de inverno e R2- rotação intensiva de culturas) no estoque de carbono (C) orgânico total, particulado e associado a minerais de um Latossolo Vermelho, originalmente degradado, do Sul do Brasil. O clima é subtropical úmido Cfa 2, segundo a classificação de Köppen, com média anual de precipitação pluvial de 1.774 mm e média anual de temperatura de 19,2 ºC. As parcelas experimentais foram divididas em três segmentos, e em cada um destes foram coletadas amostras nas profundidades de 0-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,30 m. As amostras foram coletadas por meio da abertura manual de pequenas trincheiras. O estoque de C no solo apresentou relação linear com o aporte anual de C, independentemente do sistema de preparo investigado. Assim, o preparo do solo teve pequeno efeito no incremento da taxa de decomposição da MOS. Na camada de 0-0,30 m, a taxa de sequestro de C variou de zero a 0,51 Mg ha-1 ano-1 considerando o tratamento CT R0 como referência, sendo a rotação de culturas uma estratégia mais eficiente em determinar o acúmulo de C do que os sistemas de preparo. Na média dos sistemas de cultura, uma taxa de sequestro de C de 0,13 Mg ha-1ano-1 foi observada sob PD em relação ao PC. Isso é claro? Esse resultado foi determinado pelo maior aporte de C proporcionado pela melhoria da qualidade do solo em PD adotado por longo prazo. A fração particulada de C foi um indicador eficiente da qualidade dos sistemas de manejo, enquanto o C orgânico associado aos minerais foi um importante dreno de C-CO2 atmosférico nesse Latossolo argiloso. A retenção de C nessa fração estável da MOS contribuiu com 81 e 89 % do total de C sequestrado no solo em PD, nos sistemas R1 e R2, respectivamente. O maior índice de manejo de C foi verificado sob PD R2, confirmando o potencial de práticas de manejo em melhorar qualitativamente o C armazenado no solo, em relação ao PC R0. Esses resultados mostram que a diversificação da rotação de culturas, notadamente com a inclusão de plantas de cobertura, é uma importante estratégia para o sequestro de C-CO2 atmosférico e melhoria da qualidade da MOS em Latossolos subtropicais intemperizados. Abstract in english Soil organic matter (SOM) plays a crucial role in soil quality and can act as an atmospheric C-CO2 sink under conservationist management systems. This study aimed to evaluate the long-term effects (19 years) of tillage (CT-conventional tillage and NT-no tillage) and crop rotations (R0-monoculture sy [...] stem, R1-winter crop rotation, and R2- intensive crop rotation) on total, particulate and mineral-associated organic carbon (C) stocks of an originally degraded Red Oxisol in Cruz Alta, RS, Southern Brazil. The climate is humid subtropical Cfa 2a (Köppen classification), the mean annual precipitation 1,774 mm and mean annual temperature 19.2 ºC. The plots were divided into four segments, of which each was sampled in the layers 0-0.05, 0.05-0.10, 0.10-0.20, and 0.20-0.30 m. Sampling was performed manually by opening small trenches. The SOM pools were determined by physical fractionation. Soil C stocks had a linear relationship with annual crop C inputs, regardless of the tillage systems. Thus, soil disturbance had a minor effect on SOM turnover. In the 0-0.30 m layer, soil C sequestration ranged from 0 to 0.51 Mg ha-1 yr-1, using the CT R0 treatment as base-line; crop rotation systems had more influence on soil stock C than tillage systems. The mean C sequestration rate of the cropping systems was 0.13 Mg ha-1 yr-1 higher in NT than CT. This result w

Ben-Hur Costa de, Campos; Telmo Jorge Carneiro, Amado; Cimélio, Bayer; Rodrigo da Silveira, Nicoloso; Jackson Ernani, Fiorin.

2011-06-01

82

Nitrogen dynamics in soybean-based crop rotations under conventional and zero tillage in Brazil  

International Nuclear Information System (INIS)

Approximately 70% of Brazilian agriculture is based on the cultivation of highly weathered soils located in tropical and subtropical savannah areas, where the zero or no tillage (ZT) system is now considered as the best alternative to the traditional conventional tillage (CT). During the period 1999-2004 the Agrobiology Centre of Embrapa implemented a research program using nuclear and related techniques to study the main processes involved in the dynamics and cycling of N for predominant crop rotations grown at five locations under ZT in comparison to CT, on acidic savannah soils of both southern and Cerrado regions of Brazil. The most relevant results of these studies were: (1) The soybean crop derived a high proportion of its N (over 80%) from biological nitrogen fixation (BNF). The BNF system is so efficient that attempts to increase grain yields by addition of N fertilizer are hardly ever successful as long as the plants have been effectively inoculated with the recommended Bradyrhizobium strains. (2) The N fertilizer use efficiency by the maize crop fertilized with 80 to 90 kg N ha-1 varied from 40 to 60%. (3). A maximum 10% of N-urea applied broadcast over the soil surface (40 kg N ha-1) in a maize crop was lost via NH3 volatilization, with the highest values under ZT. (4). The inclusion of green manure legumes (GMLs) such as lupin and vetch, which are highly efficient in BNF was essential to promote a positive soil N balance inal to promote a positive soil N balance in crop rotations and to increase the stock of soil organic C. (5) Less than 900 g N-N2O ha-1 yr-1 were lost from the soil surface, and the highest values were found under CT. (6) Even thought the contribution of BNF to the Brazilian soybean crop is high (over 80%), the accurate assessment of this input to the soil N balance still remain unclear due to methodological problems using the leaf labeling technique to estimate residual below-ground N. Results obtained so far suggest that these methodological issues need to be overcome before these estimates can be considered as reliable. These results demonstrate the enormous potential impact of BNF in legumes such as soybean and green manures and their management under ZT and CT on the N cycling processes and overall C and N stocks in tropical acid savannah soils, thus contributing to the productivity and sustainability of the agricultural production systems. (author)

83

Nitrous oxide emissions from crop rotations including wheat, oilseed rape and dry peas  

Science.gov (United States)

Approximately 65% of anthropogenic emissions of N2O, a potent greenhouse gas (GHG), originate from soils at a global scale, and particularly after N fertilisation of the main crops in Europe. Thanks to their capacity to fix atmospheric N2 through biological fixation, legumes can reduce N fertilizer use, and possibly N2O emissions. Nevertheless, the decomposition of crop organic matter during the crop cycle and residue decomposition, and possibly the N fixation process itself, could lead to N2O emissions. The objective of this study was to quantify N2O emissions from a dry pea crop (Pisum sativum, harvested at maturity) and from the subsequent crops in comparison with N2O emissions from wheat and oilseed rape crops, fertilized or not, in various rotations. A field experiment was conducted over 4 consecutive years to compare the emissions during the pea crop, in comparison with those during the wheat (fertilized or not) or oilseed rape crops, and after the pea crop, in comparison with other preceding crops. N2O fluxes were measured using static chambers. In spite of low N2O fluxes, mainly due to the site's soil characteristics, fluxes during the crop were significantly lower for pea and unfertilized wheat than for fertilized wheat and oilseed rape. The effect of the preceding crop was not significant, while soil mineral N at harvest was higher after the pea crop. These results should be confirmed over a wider range of soil types. Nevertheless, they demonstrate the absence of N2O emissions linked to the symbiotic N fixation process, and allow us to estimate the decrease in N2O emissions by 20-25% through including one pea crop in a three-year rotation. On a larger scale, this reduction of GHG emissions at field level has to be added to the decrease due to the reduced production and transport of the N fertilizer not applied to the pea crop.

Jeuffroy, M. H.; Baranger, E.; Carrouée, B.; de Chezelles, E.; Gosme, M.; Hénault, C.; Schneider, A.; Cellier, P.

2013-03-01

84

Análise econômica de sistemas de rotação de culturas para trigo, num período de dez anos, sob plantio direto Economic analysis of crop rotation systems for wheat, over a ten year period, under no-tillage  

Directory of Open Access Journals (Sweden)

Full Text Available Durante os anos de 1984 a 1993, foi conduzido, em Guarapuava, PR, experimento composto de sistemas de rotação de culturas para trigo: sistema I (trigo/soja; sistema II (trigo/soja e ervilhaca/milho, de 1984 a 1989, e trigo/soja e aveia-branca/soja, de 1990 a 1993; sistema III (trigo/soja, linho/soja e ervilhaca/milho, de 1984 a 1989, e trigo/soja, ervilhaca/milho e aveia-branca/soja, de 1990 a 1993; e sistema IV (trigo/soja, leguminosas/milho, cevada/soja e aveia-branca/soja. A análise econômica do período é apresentada neste trabalho. De 1984 a 1989, os sistemas I, II, III e IV não mostraram diferenças entre as médias quanto à receita líquida. Da mesma forma, de 1990 a 1993, os sistemas II, III e IV não diferiram significativamente no tocante a receita líquida, em relação ao sistema I; no entanto, considerando-se as comparações anuais, o sistema II apresentou maior lucratividade do que o sistema I, em seis anos, e não diferiu em quatro anos, sendo, portanto, aquele, uma boa alternativa em relação a este, principalmente no primeiro período.From 1984 to 1993, in Guarapuava, Paraná, Brazil, the effect of crop rotation systems on wheat were assessed. Four rotation systems for wheat were studied: system I (wheat/soybean; system II (wheat/soybean and common vetch/corn, from 1984 to 1989, and wheat/soybean and white oats/soybean, from 1990 to 1993; system III (wheat/soybean, flax/soybean, and common vetch/corn, from 1984 to 1989, and wheat/soybean, common vetch/corn, and white oats/soybean, from 1990 to 1993; and system IV (wheat/soybean, legume/corn, barley/soybean, and white oats/soybean. The economic analysis on that period is presented in this paper. From 1984 to 1989, systems I, II, III, and IV showed no differences in their net return means. Similarly, from 1990 to 1993, systems II, III, and IV mean net returns did not differ significantly in relation to the system I; however, considering the annual comparison, the system II showed higher profit than the system I in six years and did not differ in four years, making it a good alternative, mainly in the first period.

Henrique Pereira dos Santos

1999-12-01

85

Tracking nitrogen losses in a greenhouse crop rotation experiment in North China using the EU-Rotate{sub N} simulation model  

Energy Technology Data Exchange (ETDEWEB)

Vegetable production in China is associated with high inputs of nitrogen, posing a risk of losses to the environment. Organic matter mineralisation is a considerable source of nitrogen (N) which is hard to quantify. In a two-year greenhouse cucumber experiment with different N treatments in North China, non-observed pathways of the N cycle were estimated using the EU-Rotate{sub N} simulation model. EU-Rotate{sub N} was calibrated against crop dry matter and soil moisture data to predict crop N uptake, soil mineral N contents, N mineralisation and N loss. Crop N uptake (Modelling Efficiencies (ME) between 0.80 and 0.92) and soil mineral N contents in different soil layers (ME between 0.24 and 0.74) were satisfactorily simulated by the model for all N treatments except for the traditional N management. The model predicted high N mineralisation rates and N leaching losses, suggesting that previously published estimates of N leaching for these production systems strongly underestimated the mineralisation of N from organic matter. - The EU-Rotate{sub N} model can satisfactorily simulate crop N uptake and N{sub min} dynamics in a typical greenhouse cucumber production system of North China

Guo Ruiying [Ministry of Education Key Laboratory of Arid and Grassland Ecology, School of Life Sciences, Lanzhou University, No. 222 Tianshui Nanlu, Lanzhou 730000, Gansu Province (China); Nendel, Claas, E-mail: nendel@zalf.d [Institute for Landscape Systems Analysis, Leibniz-Center for Agricultural Landscape Research, Eberswalder Strasse 84, 15374 Muencheberg (Germany); Rahn, Clive [Warwick HRI, Wellesbourne CV35 9EF (United Kingdom); Jiang Chunguang; Chen Qing [College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian, Beijing 100193 (China)

2010-06-15

86

Effects of contrasting catch crops on nitrogen availability and nitrous oxide emissions in an organic cropping system  

DEFF Research Database (Denmark)

Legume-based catch crops (LBCCs) may act as an important source of nitrogen (N) in organic crop rotations because of biological N fixation. However, the potential risk of high nitrous oxide (N2O) emissions needs to be taken into account when including LBCCs in crop rotations. Here, we report the results from a one-year field experiment, which investigated N availability and N2O emissions as affected by three LBCCs, i.e., red clover (CL), red clover–ryegrass mixture (GC) and winter vetch (WV), two non-LBCCs, i.e., perennial ryegrass (GR) and fodder radish (FR), and a control (CO) without catch crops. The effect of two catch crop management strategies was also tested: autumn harvest of the catch crop versus incorporation of whole-crop residues by spring ploughing. LBCCs accumulated 59–67 kg N ha?1 in their tops, significantly more than those of the non-LBCC, 32–40 kg N ha?1. Macro-roots accounted for >33% of total N in the catch crops. In accordance with this, LBCCs enhanced the performance of the succeeding unfertilised spring barley, thus obtaining a grain yield of 3.3–4.5 Mg ha?1 compared to 2.6–3.3 Mg ha?1 grain yield from non-LBCC and the fallow control treatments. Autumn harvest of catch crops, especially LBCCs, tended to reduce crop yield. The annual N2O emissions were comparable across treatments except for fodder radish, which had the highest N2O emission, and also the highest average yield-scaled N2O emission, at 499 g N2O-N Mg?1 grain. Although the sampling strategy employed in this study introduces uncertainty about the spatial and temporal variability, differences in seasonal emission patterns among catch crops were captured and harvest of catch crops in late autumn induced significantly higher emissions during winter, but lower emissions after residue incorporation in spring. In comparison with non-LBCC, LBCCs have the potential to partly replace the effect of manure application in organic cropping systems with greater crop production and less environmental footprint with respect to N2O emissions. However, harvest of the catch crops may reduce crop yield unless the harvested N is recycled as fertiliser to the crops in the rotation.

Li, Xiaoxi; Petersen, SØren O

2015-01-01

87

Long-term C-CO2 emissions and carbon crop residue mineralization in an oxisol under different tillage and crop rotation systems Emissões deC-CO2 de longo prazo e a mineralização do carbono dos resíduos culturais em um latossolo sob diferentes sistemas de preparo e rotação de culturas  

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Full Text Available Soil C-CO2 emissions are sensitive indicators of management system impacts on soil organic matter (SOM. The main soil C-CO2 sources at the soil-plant interface are the decomposition of crop residues, SOM turnover, and respiration of roots and soil biota. The objectives of this study were to evaluate the impacts of tillage and cropping systems on long-term soil C-CO2 emissions and their relationship with carbon (C mineralization of crop residues. A long-term experiment was conducted in a Red Oxisol in Cruz Alta, RS, Brazil, with subtropical climate Cfa (Köppen classification, mean annual precipitation of 1,774 mm and mean annual temperature of 19.2 ºC. Treatments consisted of two tillage systems: (a conventional tillage (CT and (b no tillage (NT in combination with three cropping systems: (a R0- monoculture system (soybean/wheat, (b R1- winter crop rotation (soybean/wheat/soybean/black oat, and (c R2- intensive crop rotation (soybean/ black oat/soybean/black oat + common vetch/maize/oilseed radish/wheat. The soil C-CO2 efflux was measured every 14 days for two years (48 measurements, by trapping the CO2 in an alkaline solution. The soil gravimetric moisture in the 0-0.05 m layer was determined concomitantly with the C-CO2 efflux measurements. The crop residue C mineralization was evaluated with the mesh-bag method, with sampling 14, 28, 56, 84, 112, and 140 days after the beginning of the evaluation period for C measurements. Four C conservation indexes were used to assess the relation between C-CO2 efflux and soil C stock and its compartments. The crop residue C mineralization fit an exponential model in time. For black oat, wheat and maize residues, C mineralization was higher in CT than NT, while for soybean it was similar. Soil moisture was higher in NT than CT, mainly in the second year of evaluation. There was no difference in tillage systems for annual average C-CO2 emissions, but in some individual evaluations, differences between tillage systems were noticed for C-CO2 evolution. Soil C-CO2 effluxes followed a bi-modal pattern, with peaks in October/November and February/March. The highest emission was recorded in the summer and the lowest in the winter. The C-CO2 effluxes were weakly correlated to air temperature and not correlated to soil moisture. Based on the soil C conservation indexes investigated, NT associated to intensive crop rotation was more C conserving than CT with monoculture.A emissão de C-CO2 do solo é considerada um indicador sensível dos impactos de sistemas de manejo sobre a matéria orgânica do solo (MOS. Nos sistemas agrícolas, as principais fontes de C-CO2 são as decomposições dos resíduos culturais e da MOS, além da respiração das raízes das culturas e da biota do solo. O principal objetivo deste estudo foi avaliar o impacto de sistemas de preparo do solo e culturas nas emissões de longo prazo de C-CO2 do solo e sua relação com a mineralização do carbono (C de resíduos culturais. Este estudo foi desenvolvido em experimento de longa duração, em Latossolo Vermelho distrófico típico, de ocorrência na região de Cruz Alta, RS, Brasil. O clima é o subtropical Cfa, segundo a classificação de Köppen, com precipitação pluvial anual média de 1.744 mm e temperatura média anual de 19,2 ºC. Os tratamentos investigados foram dois sistemas de preparo - convencional (PC e plantio direto (PD - e três sistemas de culturas: R0- sucessão de monoculturas (trigo/soja; R1- rotação de culturas de inverno (aveia-preta/soja/trigo/soja; e R2- rotação intensiva de culturas (aveia-preta/soja/aveia-preta+ervilhaca/milho /nabo forrageiro/trigo/soja. O efluxo de C-CO2 do solo foi avaliado em intervalos fixos de 14 dias, durante dois anos (48 avaliações, por meio da captura do dióxido de carbono em solução alcalina. A umidade gravimétrica do solo, na camada de 0-0,05 m, foi determinada concomitantemente com as medições de C-CO2. Ainda, foi avaliada a taxa de liberação do C dos resíduos culturais utilizando o método dos sacos de decomposição, com am

Ben-Hur Costa de Campos

2011-06-01

88

Thlaspi arvense (Pennycress): An off-season energy crop within the corn-soybean rotation  

Science.gov (United States)

Pennycress is being developed as an off-season rotation crop between annual corn and soybean production. This rotation scheme may offer distinct advantages to farmers by providing additional farm income from an otherwise fallow season with little impact on the subsequent soybean production. The seed...

89

Soil enzyme activities under long-term tillage and crop rotation systems in subtropical agro-ecosystems Atividade enzimática em solo sob plantio direto e rotações de culturas em agro-ecossistema subtropical  

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Full Text Available Agricultural practices that reduce soil degradation and improve agricultural sustainability are needed particularly for tropical/subtropical soils. No-tillage planting causes minimal soil disturbance and combined with crop rotation may hold potential to meet these goals. Soil enzyme activities can provide information on how soil management is affecting the potential to perform the processes in soils such as decomposition and nutrient cycling. Soil enzyme activities were investigated in a split-plot experiment (3 replications where tillage (no till and conventional was the main plot and crop rotation (soybean/wheat, S/W; maize/wheat, M/W or cotton/wheat, C/W was the subplot. The experiment was established in 1976 in southern Brazil. Soil samples were taken at 0-5, 5-10 and 10-20 cm depths in 1997 and 1998. The 0-5 cm layer under NT system showed increases up 68% for amylase, 90% for cellulase, 219% for arylsulfatase, 46% for acid phosphatase, and 61% for alkaline phosphatase. There were significant correlations of soil enzyme activities with total organic C, and C and N microbial biomass. These results showed that NT increased microbial activity and that soil enzyme activity is a sensitive indicator of alteration soil quality by management.Práticas agrícolas que reduzam a degradação do solo e promovam sustentabilidade são importantes para os agrossistemas tropicais/subtropicais. O plantio direto (PD diminui as perdas de solo e, se combinado com rotação de culturas pode proteger o solo da degradação físico-química provocada pela agricultura intensiva. A atividade enzimática do solo pode fornecer importantes informações de como o manejo do solo está afetando a decomposição da material orgânica e a ciclagem dos nutrientes. Assim, avaliou-se a atividade das enzimas amilase, celulose, arilsulfatase, fosfatase ácida e fosfatase alcalina em um experimento a campo, instalado em 1976 em Londrina, PR, que tem como tratamentos o preparo do solo (plantio direto ou convencional nas parcelas e a rotação de culturas (soja/trigo, milho/trigo e algodão/trigo nas subparcelas. Amostras de solos foram coletadas a 0-5, 5-10 e 10-20 cm de profundidade em 1997 e 1998. Na profundidade de 0-5 cm sob PD, observaram-se aumentos de 68% na atividade da amilase, 90% na celulase, 219% na arilsulfatase, 46% na fosfatase ácida e 61% na fosfatase alcalina. Observaram-se correlações significativas entre a atividade enzimática e o C-orgânico total do solo e o C e N da biomassa microbiana. Esses resultados evidenciam que a atividade enzimática do solo é um indicador sensível de alterações na qualidade do solo, promovidas pelo manejo.

Elcio Liborio Balota

2004-12-01

90

Comparison of simulated and observed N2O gas emission rates from bioenergy cropping systems  

Science.gov (United States)

Nitrous oxide is the largest greenhouse gas source from crop systems. DAYCENT was used to compare N2O emissions from the following 3 bioenergy cropping systems: switchgrass, reed canarygrass, and a rotation of 3 yr corn, 1 yr soybeans, and 4 yr alfalfa. Although DAYCENT did not always capture the ob...

91

Effects of crop rotation and soil tillage on weeds in organic farming  

Directory of Open Access Journals (Sweden)

Full Text Available An organic long-term field experiment with two factors has been carried out since 1998 at the experimental station Gladbacherhof, University of Giessen. Effects of 3 different farm types (with lifestock raising, stockless farming with rotational set-aside, stockless farming only cash crops combined with 4 tillage treatments (mouldboard plough, two-layer-plough, reduced tillage depth and tillage without plough on plants, soil and environment have been investigated. This article presents results on the coverage rate of arable wild plants (weed coverage, the range of weed species, the abundance of C. arvense (L. Scop. (Canada thistle and the weed phytomass during harvest time of the main crops dependent on farm type and soil tillage. It can be concluded that, compared to conventional economic weed thresholds, the weed coverage was generally relatively low and only limited ranges of species were found. Wild arable plants probably did not have any impact on yields of the cultivated plants due to intensive mechanical regulatory measures. In stockless organic farming without alfalfa-grass in the crop rotation Cirsium arvense (L. Scop. (Canada thistle might become a problem whereas this perennial root-weed does not seem to raise a long term problem in a soil tillage system without ploughing. In all treatments the abundance of weeds like Galium aparine L. (catchweed bedstraw and Stellaria media L. (chickweed was high. However, none of the farm types or soil tillage systems succeeded in providing evidence of promoting rare species or encouraging biodiversity. In order to achieve this special support measures should be implemented.

Schulz, Franz

2014-02-01

92

INFLUÊNCIA DO PREPARO DE SOLO E DA ROTAÇÃO DE CULTURAS NA SEVERIDADE DE PODRIDÕES RADICULARES NO FEIJOEIRO COMUM EFFECTS OF SOIL TILLAGE SYSTEM AND CROP ROTATION ON DRY BEAN ROOT ROT SEVERITY  

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Full Text Available

As podridões radiculares do feijoeiro são causadas pelos fungos Rhizoctonia solani Kühn e Fusarium solani f. sp. phaseoli Snyd. & Hans. Neste trabalho testou-se a combinação dos fatores preparo de solo e rotação de culturas, além de se avaliarem seus efeitos sobre as podridões radiculares do feijoeiro. Os tipos de preparo de solo consistiram em: arado+grade (P1, arado (P2, grade (P3 e plantio direto (P4. As rotações de culturas foram: arroz-feijão (R1, milho-feijão (R2, arroz/calopogônio (Calopogonium muconoides-feijão (R3 e milho-feijão-milho-feijão-arroz-feijão (R4. A severidade de F. solani f. sp. phaseoli, avaliada aos 25 dias após o plantio, apresentou interação significativa, sendo a maior severidade encontrada na combinação da rotação R3 com o preparo de solo P1, e a menor severidade, na combinação da rotação R2 com o preparo de solo P3. Diferenças estatísticas ocorreram na severidade da doença provocada por R. solani. O preparo de solo P3 apresentou maior severidade que P4, e, entre as rotações, R3 apresentou a maior severidade da doença.

PALAVRAS-CHAVE: Rhizoctonia solani; Fusarium solani f. sp. phaseoli; práticas culturais; fungos.

Dry bean root rot is caused by the fungi Rhizoctonia solani Kühn and Fusarium solani f. sp. phaseoli Snyd. & Hans.The effects of the interaction between soil tillage systems andcrop rotation on the severity of root rot was tested. The soiltillage systems consisted of plough+harrow (P1, plough (P2,harrow (P3 and no tillage (P4 and the crop rotation treatmentswere rice-bean (R1, corn-bean (R2, rice/Calopogonium muconoides-bean (R3 and corn-bean-corn-bean-rice-bean (R4. The severity of F. solani f. sp. phaseoli was evaluated 25 days after planting. The interaction was significant for this variable. The higher severity was under R3 with soil tillage system treatment P1. The lowest severity was under interaction R2 with soil preparation P3. Significant differences were found in the severity of the disease caused by R. solani. Soil tillage system P3 presented significantly higher disease severity than P4, whereas rotation R3 presented significantly higher disease severity when compared to other treatments.

KEY-WORDS: Rhizoctonia solani, Fusarium solani f. sp. haseoli; cropping practices; fungi.

Pedro Marques da Silveira

2007-09-01

93

Simulated effects of crop rotations and residue management on wind erosion in Wuchuan, west-central Inner Mongolia, China.  

Science.gov (United States)

For decades, wind erosion has triggered dust and sand storms, buffeting Beijing and areas of northwestern China to the point of being hazardous to human health while rapidly eroding crop and livestock productivity. The EPIC (Environmental Policy Integrated Climate) field-scale simulation model was used to assess long-term effects of improved crop rotations and crop residue management practices on wind erosion in Wuchuan County in Inner Mongolia. Simulation results indicate that preserving crop stalks until land is prepared by zone tillage for the next year's crop in lieu of using them as a source of heating fuel or livestock fodder significantly reduces wind erosion by 60%. At the same time, grain and potato (Solanum tuberosum L.) yields were maintained or improved. Significant reductions in erosion, 35 to 46%, also resulted from delaying stalk removal until late January through late April. Yearly wind erosion was concentrated in April and May, the windiest months. Additionally, the use of alternative crop rotations resulted in differences in wind erosion, largely due to a difference in residue stature and quality and differences in biomass produced. As a result, altering current crop rotation systems by expanding corn (Zea mays L.), wheat (Triticum aestivum L.), and millet [Sorghum bicolor (L.) Moench] and reducing potato and pea (Pisum sativum L.) production significantly reduced simulated wind erosion, thus diminishing the severity of dust and sand storms in northwestern China. Saving and protecting topsoil over time will sustain land productivity and have long-term implications for improving conditions of rural poverty in the region. PMID:12175042

Wang, Erda; Harman, Wyatte L; Williams, Jimmy R; Xu, Cheng

2002-01-01

94

Propriedades físicas do solo em sistemas de rotação de culturas conforme o uso de corretivos da acidez / Soil physical properties in crop rotation systems as affected by liming materials  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar o efeito de sistemas de rotação de culturas e de corretivos da acidez nas propriedades físicas do solo. O experimento foi realizado entre outubro de 2006 e julho de 2008, em Botucatu, SP, em blocos ao acaso, com parcelas subdivididas e oito repetições. As parcel [...] as foram constituídas por quatro sistemas de rotação: soja/pousio/milho/pousio, soja/aveia-branca/milho/feijão, soja/milheto/milho/guandu e soja/braquiária/milho/braquiária. As subparcelas consistiram do tratamento testemunha, sem correção, e da aplicação de 3,8 Mg ha-1 de calcário dolomítico (PRNT = 90%) ou de 4,1 Mg ha-1 de silicato de cálcio e magnésio (PRNT = 80%), na superfície de um Latossolo Vermelho argiloso. Foram determinadas: estabilidade de agregados, densidade do solo, porosidade total, macro e microporosidade, resistência do solo à penetração e umidade do solo. A aplicação dos corretivos de acidez em superfície não reduz a agregação do solo e aumenta a macroporosidade até 0,20 m de profundidade, após aplicação de silicato, e até 0,10 m, após aplicação de calcário. A manutenção do solo em pousio, na entressafra, prejudica a estruturação do solo, reduz a estabilidade de agregados e aumenta a resistência à penetração nas camadas superficiais. A semeadura de braquiária, entre as safras de verão, aumenta a estabilidade de agregados até 0,10 m de profundidade. Abstract in english The objective of this work was to evaluate the effects of crop rotation systems and liming materials on soil physical properties. The experiment was carried out from October 2006 to July 2008, in Botucatu, SP, Brazil, in a completely randomized block design in a split-plot arrangement with eight rep [...] licates. Main plots consisted of four crop rotation systems: soybean/fallow/maize/fallow, soybean/white-oat/maize/bean, soybean/millet/maize/pigeon pea and soybean/signal grass/maize/signal grass. Subplots consisted of the control treatment, without soil correction, and of the application of 3.8 Mg ha-1 of dolomitic lime (ECC = 90%) or 4.1 Mg ha-1 of calcium-magnesium silicate (ECC = 80%), on the surface of a clayed Rhodic Ferralsol. Aggregate stability, soil bulk density, total porosity, macro and microporosity, soil penetration resistance and moisture content were evaluated. Superficial application of the lime materials does not reduce soil aggregation and increases macroporosity down to 0.20 m, with calcium-magnesium silicate application, and to 0.10 m, when lime is applied. Soil under fallow in off-season decreases aggregate stability and increases soil penetration resistance in upper layers. The cultivation of Congo signal grass, between summer crops, increases aggregate stability down to 0.10-m depth.

Gustavo Spadotti Amaral, Castro; Juliano Carlos, Calonego; Carlos Alexandre Costa, Crusciol.

1690-16-01

95

Propriedades físicas do solo em sistemas de rotação de culturas conforme o uso de corretivos da acidez Soil physical properties in crop rotation systems as affected by liming materials  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi avaliar o efeito de sistemas de rotação de culturas e de corretivos da acidez nas propriedades físicas do solo. O experimento foi realizado entre outubro de 2006 e julho de 2008, em Botucatu, SP, em blocos ao acaso, com parcelas subdivididas e oito repetições. As parcelas foram constituídas por quatro sistemas de rotação: soja/pousio/milho/pousio, soja/aveia-branca/milho/feijão, soja/milheto/milho/guandu e soja/braquiária/milho/braquiária. As subparcelas consistiram do tratamento testemunha, sem correção, e da aplicação de 3,8 Mg ha-1 de calcário dolomítico (PRNT = 90% ou de 4,1 Mg ha-1 de silicato de cálcio e magnésio (PRNT = 80%, na superfície de um Latossolo Vermelho argiloso. Foram determinadas: estabilidade de agregados, densidade do solo, porosidade total, macro e microporosidade, resistência do solo à penetração e umidade do solo. A aplicação dos corretivos de acidez em superfície não reduz a agregação do solo e aumenta a macroporosidade até 0,20 m de profundidade, após aplicação de silicato, e até 0,10 m, após aplicação de calcário. A manutenção do solo em pousio, na entressafra, prejudica a estruturação do solo, reduz a estabilidade de agregados e aumenta a resistência à penetração nas camadas superficiais. A semeadura de braquiária, entre as safras de verão, aumenta a estabilidade de agregados até 0,10 m de profundidade.The objective of this work was to evaluate the effects of crop rotation systems and liming materials on soil physical properties. The experiment was carried out from October 2006 to July 2008, in Botucatu, SP, Brazil, in a completely randomized block design in a split-plot arrangement with eight replicates. Main plots consisted of four crop rotation systems: soybean/fallow/maize/fallow, soybean/white-oat/maize/bean, soybean/millet/maize/pigeon pea and soybean/signal grass/maize/signal grass. Subplots consisted of the control treatment, without soil correction, and of the application of 3.8 Mg ha-1 of dolomitic lime (ECC = 90% or 4.1 Mg ha-1 of calcium-magnesium silicate (ECC = 80%, on the surface of a clayed Rhodic Ferralsol. Aggregate stability, soil bulk density, total porosity, macro and microporosity, soil penetration resistance and moisture content were evaluated. Superficial application of the lime materials does not reduce soil aggregation and increases macroporosity down to 0.20 m, with calcium-magnesium silicate application, and to 0.10 m, when lime is applied. Soil under fallow in off-season decreases aggregate stability and increases soil penetration resistance in upper layers. The cultivation of Congo signal grass, between summer crops, increases aggregate stability down to 0.10-m depth.

Gustavo Spadotti Amaral Castro

2011-12-01

96

Will breeding for nitrogen use efficient crops lead to nitrogen use efficient cropping systems? : A simulation study of G*E*M interactions  

DEFF Research Database (Denmark)

The benefits of improving nitrogen use efficiency (NUE) in crops are typically studied through the performance of the individual crop. However, in order to increase yields in a sustainable way, improving NUE of the cropping systems must be the aim. We did a model simulation study to investigate how improvement of NUE traits of individual crops affects the succeeding crops and the NUE of the crop rotation. Based on experimental results parameterization was altered for different types of improved NUE in the EU-Rotate_N model, e.g. through higher N harvest index, reduced litter loss or improved root depth penetration rate. The different ways of improving NUE have different effects on the cropping system, affecting either N uptake, the ability of the crop to hold on to N already taken up, or the fraction of crop N being harvested. Due to the different modes of action, the model simulations show that these changes in NUE traits will also have different effects on N leaching loss and on N availability and N loss inthe following years. Simulations also show that the effect of genotypes with improved NUE depend on environment and crop management. This is true for the improved crop itself and when its effect is analyzed for the whole cropping system. The environmental conditions, crop choices and management will all affect the fate of the N left in the soil, and whether this will contribute mainly to leaching loss or be used for production in later crops. As an example, increasing pre-crop fertilization was shown to affect the leaching after the following oilseed rape crop with up to 50 kg N ha?1 taken up before it was lost to the environment when pre-crop fertilization as well as root depth penetration rate was high. All in all, the simulations illustrate the concept of NUE as the result of interactions between genotype, environment and crop management (G×E×M).

DresbØll, Dorte Bodin; Thorup-Kristensen, Kristian

2014-01-01

97

Will breeding for nitrogen use efficient crops lead to nitrogen use efficient cropping systems? : a simulation study of GxExM interactions  

DEFF Research Database (Denmark)

The benefits of improving nitrogen use efficiency (NUE) in crops are typically studied through the performance of the individual crop. However, in order to increase yields in a sustainable way, improving NUE of the cropping systems must be the aim. We did a model simulation study to investigate how improvement of NUE traits of individual crops affects the succeeding crops and the NUE of the crop rotation. Based on experimental results parameterization was altered for different types of improved NUE in the EU-Rotate_N model, e.g. through higher N harvest index, reduced litter loss or improved root depth penetration rate. The different ways of improving NUE have different effects on the cropping system, affecting either N uptake, the ability of the crop to hold on to N already taken up, or the fraction of crop N being harvested. Due to the different modes of action, the model simulations show that these changes in NUE traits will also have different effects on N leaching loss and on N availability and N loss inthe following years. Simulations also show that the effect of genotypes with improved NUE depend on environment and crop management. This is true for the improved crop itself and when its effect is analyzed for the whole cropping system. The environmental conditions, crop choices and management will all affect the fate of the N left in the soil, and whether this will contribute mainly to leaching loss or be used for production in later crops. As an example, increasing pre-crop fertilization was shown to affect the leaching after the following oilseed rape crop with up to 50 kg N ha?1 taken up before it was lost to the environment when pre-crop fertilization as well as root depth penetration rate was high. All in all, the simulations illustrate the concept of NUE as the result of interactions between genotype, environment and crop management (G×E×M).

DresbØll, Dorte Bodin; Thorup-Kristensen, Kristian

2014-01-01

98

Sources of Nitrogen for Winter Wheat in Organic Cropping Systems  

DEFF Research Database (Denmark)

In organic cropping systems, legumes, cover crops (CC), residue incorporation, and manure application are used to maintain soil fertility, but the contributions of these management practices to soil nitrogen (N) supply remain obscure. We examined potential sources of N for winter wheat (Triticum aestivum L.) in four experimental cropping systems established in 1997 on three soil types. Three of the four systems were under organic management. Topsoil N, depth of the A horizon, and cumulated inputs of N since 1997 were determined at plot level. Labile soil N pools [mineral N, potentially mineralizable N (PMN), microbial biomass N (MBN)] were monitored during two growth periods; at one site, biomass C/N ratios were also determined. Soil for labile N analysis was shielded from N inputs during spring application to isolate cumulated system effects. Potentially mineralizable N and MBN were correlated across all sites and rotations (r2 = 0.72). The MBN corresponded to 46 to 85, 85 to 145, and 74 to 172 kg N ha?1 at the three sites and differed significantly between cropping systems, but MBN could not explain differences in wheat grain N yields. Instead, a multiple linear regression model explained 76 and 82% of the variation in grain N yields in organic cropping systems in 2007 and 2008, showing significant effects of, respectively, topsoil N, depth of A horizon, cumulated inputs of N, and N applied to winter wheat in manure. Thus, soil properties and past and current management all contributed to winter wheat N supply.

Petersen, SØren O; SchjØnning, Per

2013-01-01

99

Economic evaluation of a crop rotation portfolio for irrigated farms in central Chile  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english The sustainable use of productive resources by agricultural producers in the central valley of Chile should be compatible with economic results so that producers can select an appropriate rotation or succession of annual crops and pasture. The objective of this work was to evaluate the economic beha [...] vior of four food crop and supplementary forage rotations using indicators of profitability and profit variability. Productive data were used from a long-term experiment (16 yr) in the central valley of Chile under conditions of irrigation. With productive data and information on historic input/output prices, the real net margin per rotation (RNMR) and its coefficient of variation (CV) were determined. The results indicated that the highest economic benefits and greatest economic stability were obtained with rotations that only included crops, namely sugar beet (Beta vulgaris L. subsp. vulgaris)-wheat (Triticum aestivum L.)-bean (Phaseolus vulgaris L.)-barley (Hordeum vulgare L.) (CR2) and corn (Zea mays L.)-wheat-bean-barley (CR4). These rotations included crops with low CV of the net margin, such as wheat, barley and beans, with values between 0.31 and 0.34. The rotations with crops and pasture, sugar beet-wheat-red clover (Trifolium pratense L.) (2) (CR1) and corn-wheat-red clover (2) (CR3) had lower net margins and more variability of this indicator. Red clover had the highest CV value (1.00). The selection of crops for rotations and their sequence were determining factors in the economic behavior of rotations, affecting the level of RNMR and the degree of inter-annual variability of this indicator. Thus, differences among rotations of 47% in net margin were determined (CR2 vs. CR1), which only differed in the replacement of pasture with red clover (2) by bean-barley. The economic analysis based on the net margin and its variability allow for discriminating among rotations, providing valuable information for producers in deciding which crops to use in rotations.

Jorge, González U; Pablo, Undurraga; Juan, Hirzel; Ingrid, Martínez G.

2013-09-01

100

AFLP analysis of genetic diversity in charcoal rot fungal populations impacted by crop rotations.  

Science.gov (United States)

The application of molecular markers enables scientists to clarify the genetic relationships among fungi who are difficult to classify or partition into sub-species using traditional morphological or physiological criteria. One such fungus is Macrophomina phaseolina, a plant pathogenic soil-borne fungus that is the causative agent of Charcoal Rot on soybeans and 500 other plant species world-wide. This plant pathogenic fungus is a very heterogeneous species and disease population dynamics and pathogen genetic diversity are poorly understood. Using a multi-variant Amplified Fragment Length Polymorphism (AFLP) approach for the analysis of genomic data, valuable insight into cultural and environmental pressures that shape the fungal genome was possible. Fungal isolates from 12-year rotated field plots ranging from 1-3 years of crop rotations of the same plant type(s), rotation duration and plant maturity groups provided a unique opportunity to survey M. phaseolina isolates taken from the different crop rotation conditions. Using different data interval partitioning of amplified restriction fragments it was possible to see trends associated with the specific cropping history of the fungal isolates. AFLP neutral primers of intermediate and large amplified products using 20-bp intervals were the most efficient and reliable for demonstrating intra-population dynamics. Results indicate that the highest amount of M. phaseolina genetic diversity was conclusively found in fungal isolates taken from three-year rotation plots. Lesser amounts of genetic diversity were found in two-year rotated and non-rotated fungal isolates. Insight gained from this study may now be incorporated into a larger understanding of how crop rotation and the availability of hosts shape and influence the genetic variability within Macrophomina isolates and populations. This information can then be used to make better-informed decisions regarding crop protection strategies against this diverse and economically important fungal pathogen. PMID:19226737

Brooker, N; Lord, J R; Long, J; Jayawardhana, A

2008-01-01

101

Climate change impacts on dryland cropping systems in the central Great Plains, USA  

Science.gov (United States)

Agricultural systems models are essential tools to assess potential climate change (CC) impacts on crop production and help guide policy decisions. In this study, impacts of GCM projected CC on dryland crop rotations of wheat-fallow (WF), wheat-corn-fallow (WCF), and wheat-corn-millet (WCM) at Akro...

102

Controle de doenças de plantas pela rotação de culturas Control of plant disease by crop rotation  

Directory of Open Access Journals (Sweden)

Full Text Available Esta revisão aborda a importância da escolha e da adoção de práticas culturais e seus reflexos na intensidade de doenças de plantas. São apresentados conceitos básicos referente ao tema e os de rotação e monocultura. Discutem-se os princípios ou fundamentos e potencialidade do uso da rotação e do manejo integrado de doenças, as consequências da nutrição de fitopatógenos, dos eventos biológicos ocorrentes nos restos culturais, as características dos fitopatógenos potencialmente controláveis e dos não controláveis pela rotação.This review deals with the importance of the selection and use of cultural practices and their reflex in plant disease intensity. Basic concepts related to the subject and crop rotation and monoculture are presented. Principles fundaments are discussed in addition to, the potential use of crop rotation integrated disease management. The consequences of plant pathogens nutrition, biological events in crop residues, characteristics of phytopathogens potentially controlled and not controlled by rotation are also dealt.

Erlei Melo Reis

2011-09-01

103

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

DEFF Research Database (Denmark)

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-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’ not in the last course) and with and without catch crops. E. repens was controlled by different tillage tactics and mowing strategies between and within crops and were conducted whenever the population had exceeded certain thresholds. Pulses, either in pure stands or in mixtures with spring barley, and spring cereals (barley and wheat) caused the highest population increases (up to eightfold), especially when preceded by grass-clover. Winter rye and potatoes with ridging cultivations were neutral to the E. repens population. Cultivations between crops were necessary to diminish the infestation and were the main reason for lower infestations in treatments without catch crops. Manuring resulted in a general reduction of E. repens by 28 % when analyzing data from all three courses. The study has identified the crop types that need particular attention when designing crop sequences, the importance of sufficient nutrients supplies to strengthen crop suppression of weeds and the need for mechanical interventions to mange E. repens satisfactorily.

Rasmussen, Ilse A.; Melander, Bo

2014-01-01

104

Winter Cereals as Double Crops in Corn Rotations on New York Dairy Farms  

Directory of Open Access Journals (Sweden)

Full Text Available Weather extremes in 2012 and 2013 impacted corn silage and hay yields for many dairies in the northeastern United States and prompted a growing interest in double cropping of winter cereals for harvest as high quality forage in the spring. Here we report on (1 forage yield ranges of cereal rye and triticale in corn-cereal rotations in New York in 2012-2014, and (2 survey results of 30 New York farm managers who grew winter cereals as double crops with corn silage in 2013. Yields averaged 3.62 and 4.88 Mg ha-1 for cereal rye and triticale, respectively. On average, the surveyed farmers planted 8% of their tillable acres to winter cereal with the intent to harvest as forage. Triticale was the most frequently seeded double crop (70%. Most stands were established with a drill (57%. Manure was applied to 37% of the fields. Fertilizer nitrogen (N was applied at dormancy break by 79% of the farmers with a median application rate of 67 kg N ha-1. The biggest challenge with the double-crop rotation, identified by the farmers, was timely seeding of the double crop in the fall given late corn silage harvest and early onset of frost in the Northeast. Despite challenges encountered and questions about the impact of harvest of the winter cereal on the main crop, 83% of the surveyed farmers planned to continue to grow double crops.

Quirine M. Ketterings

2015-01-01

105

European Perspectives on the Adoption of Nonchemical Weed Management in Reduced -Tillage Systems for Arable Crops  

DEFF Research Database (Denmark)

Noninversion tillage with tine- or disc-based cultivations prior to crop establishment is the most common way of reducing tillage for arable cropping systems with small grain cereals, oilseed rape, and maize in Europe. However, new regulations on pesticide use might hinder further expansion of reduced-tillage systems. European agriculture is asked to become less dependent on pesticides and promote crop protection programs based on integrated pest management (IPM) principles. Conventional noninversion tillage systems rely entirely on the availability of glyphosate products, and herbicide consumption is mostly higher compared to plow-based cropping systems. Annual grass weeds and catchweed bedstraw often constitute the principal weed problems in noninversion tillage systems, and crop rotations concurrently have very high proportions of winter cereals. There is a need to redesign cropping systems to allow for more diversification of the crop rotations to combat these weed problems with less herbicide input. Cover crops, stubble management strategies, and tactics that strengthen crop growth relative to weed growth are also seen as important components in future IPM systems, but their impact in noninversion tillage systems needs validation. Direct mechanical weed control methods based on rotating weeding devices such as rotary hoes could become useful in reduced-tillage systems where more crop residues and less workable soils are more prevalent, but further development is needed for effective application. Owing to the frequent use of glyphosate in reduced-tillage systems, perennial weeds are not particularly problematic. However, results from organic cropping systems clearly reveal that desisting from glyphosate use inevitably leads to more problems with perennials, which need to be addressed in future research.

Melander, Bo; Munier-Jolain, Nicolas

2013-01-01

106

Nitrous oxide emissions from crop rotations including wheat, rapeseed and dry pea  

Science.gov (United States)

Approximately 65% of anthropogenic emissions of N2O, a potent greenhouse gas, originate from soils at global scale, and particularly after N fertilisation of the main crops in Europe. Thanks to their capacity to fix atmospheric N2 through biological fixation, legumes allow to reduce N fertilizer use, and possibly N2O emission. Nevertheless, the decomposition of crop organic matter during the crop cycle and during the residue decomposition, and possibly the N fixation process itself, could lead to N2O emissions. The objective of this study was to quantify N2O emissions from a dry pea crop (Pisum sativum, harvested at maturity) and from the subsequent crops in comparison with N2O emissions from wheat and oilseed-rape crops, fertilized or not, in various rotations. A field experiment was conducted during 4 consecutive years, aiming at comparing the emissions during the pea crop, in comparison with those during the wheat (fertilized or not) or oilseed rape crops, and after the pea crop, in comparison with other preceding crops. N2O fluxes were measured using static chambers. In spite of low N2O fluxes, mainly linked with the site soil characteristics, fluxes during the crop were significantly lower for pea and unfertilized wheat than for fertilized wheat and oilseed rape. The effect of the preceding crop was not significant, while soil mineral N at harvest was higher after pea. These results, combined with the emission reduction allowed by the production and transport of the N fertiliser not applied on the pea crop, should be confirmed in a larger range of soil types. Nevertheless, they demonstrate the absence of N2O emission linked to the symbiotic N fixation process, and allow us to estimate the decrease of N2O emissions to 20-25% by including one pea crop in a three-year rotation. At a larger scale, this reduction of GHG emissions at field level has to be cumulated with the reduction of GHG emissions linked with the lower level of production and transport of the N fertiliser not applied on the pea crop.

Jeuffroy, M. H.; Baranger, E.; Carrouée, B.; de Chezelles, E.; Gosme, M.; Hénault, C.; Schneider, A.; Cellier, P.

2012-07-01

107

Nitrous oxide emissions from crop rotations including wheat, rapeseed and dry pea  

Directory of Open Access Journals (Sweden)

Full Text Available Approximately 65% of anthropogenic emissions of N2O, a potent greenhouse gas, originate from soils at global scale, and particularly after N fertilisation of the main crops in Europe. Thanks to their capacity to fix atmospheric N2 through biological fixation, legumes allow to reduce N fertilizer use, and possibly N2O emission. Nevertheless, the decomposition of crop organic matter during the crop cycle and during the residue decomposition, and possibly the N fixation process itself, could lead to N2O emissions. The objective of this study was to quantify N2O emissions from a dry pea crop (Pisum sativum, harvested at maturity and from the subsequent crops in comparison with N2O emissions from wheat and oilseed-rape crops, fertilized or not, in various rotations. A field experiment was conducted during 4 consecutive years, aiming at comparing the emissions during the pea crop, in comparison with those during the wheat (fertilized or not or oilseed rape crops, and after the pea crop, in comparison with other preceding crops. N2O fluxes were measured using static chambers. In spite of low N2O fluxes, mainly linked with the site soil characteristics, fluxes during the crop were significantly lower for pea and unfertilized wheat than for fertilized wheat and oilseed rape. The effect of the preceding crop was not significant, while soil mineral N at harvest was higher after pea. These results, combined with the emission reduction allowed by the production and transport of the N fertiliser not applied on the pea crop, should be confirmed in a larger range of soil types. Nevertheless, they demonstrate the absence of N2O emission linked to the symbiotic N fixation process, and allow us to estimate the decrease of N2O emissions to 20–25% by including one pea crop in a three-year rotation. At a larger scale, this reduction of GHG emissions at field level has to be cumulated with the reduction of GHG emissions linked with the lower level of production and transport of the N fertiliser not applied on the pea crop.

M. H. Jeuffroy

2012-07-01

108

Energy Product Options for Eucalyptus Species Grown as Short Rotation Woody Crops  

OpenAIRE

Eucalyptus species are native to Australia but grown extensively worldwide as short rotation hardwoods for a variety of products and as ornamentals. We describe their general importance with specific emphasis on existing and emerging markets as energy products and the potential to maximize their productivity as short rotation woody crops. Using experience in Florida USA and similar locations, we document their current energy applications and assess their productivity as short-term and likely ...

Winandy, Jerrold E.; Zhu, J. Y.; Ralph, Sally A.; Rudie, Alan W.; Rockwood, Donald L.

2008-01-01

109

Energy product options for eucalyptus species grown as short rotation woody crops.  

Science.gov (United States)

Eucalyptus species are native to Australia but grown extensively worldwide as short rotation hardwoods for a variety of products and as ornamentals. We describe their general importance with specific emphasis on existing and emerging markets as energy products and the potential to maximize their productivity as short rotation woody crops. Using experience in Florida USA and similar locations, we document their current energy applications and assess their productivity as short-term and likely long-term energy and related products. PMID:19325808

Rockwood, Donald L; Rudie, Alan W; Ralph, Sally A; Zhu, J Y; Winandy, Jerrold E

2008-08-01

110

Soil enzyme activities under long-term tillage and crop rotation systems in subtropical agro-ecosystems / Atividade enzimática em solo sob plantio direto e rotações de culturas em agro-ecossistema subtropical  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Práticas agrícolas que reduzam a degradação do solo e promovam sustentabilidade são importantes para os agrossistemas tropicais/subtropicais. O plantio direto (PD) diminui as perdas de solo e, se combinado com rotação de culturas pode proteger o solo da degradação físico-química provocada pela agric [...] ultura intensiva. A atividade enzimática do solo pode fornecer importantes informações de como o manejo do solo está afetando a decomposição da material orgânica e a ciclagem dos nutrientes. Assim, avaliou-se a atividade das enzimas amilase, celulose, arilsulfatase, fosfatase ácida e fosfatase alcalina em um experimento a campo, instalado em 1976 em Londrina, PR, que tem como tratamentos o preparo do solo (plantio direto ou convencional) nas parcelas e a rotação de culturas (soja/trigo, milho/trigo e algodão/trigo) nas subparcelas. Amostras de solos foram coletadas a 0-5, 5-10 e 10-20 cm de profundidade em 1997 e 1998. Na profundidade de 0-5 cm sob PD, observaram-se aumentos de 68% na atividade da amilase, 90% na celulase, 219% na arilsulfatase, 46% na fosfatase ácida e 61% na fosfatase alcalina. Observaram-se correlações significativas entre a atividade enzimática e o C-orgânico total do solo e o C e N da biomassa microbiana. Esses resultados evidenciam que a atividade enzimática do solo é um indicador sensível de alterações na qualidade do solo, promovidas pelo manejo. Abstract in english Agricultural practices that reduce soil degradation and improve agricultural sustainability are needed particularly for tropical/subtropical soils. No-tillage planting causes minimal soil disturbance and combined with crop rotation may hold potential to meet these goals. Soil enzyme activities can p [...] rovide information on how soil management is affecting the potential to perform the processes in soils such as decomposition and nutrient cycling. Soil enzyme activities were investigated in a split-plot experiment (3 replications) where tillage (no till and conventional) was the main plot and crop rotation (soybean/wheat, S/W; maize/wheat, M/W or cotton/wheat, C/W) was the subplot. The experiment was established in 1976 in southern Brazil. Soil samples were taken at 0-5, 5-10 and 10-20 cm depths in 1997 and 1998. The 0-5 cm layer under NT system showed increases up 68% for amylase, 90% for cellulase, 219% for arylsulfatase, 46% for acid phosphatase, and 61% for alkaline phosphatase. There were significant correlations of soil enzyme activities with total organic C, and C and N microbial biomass. These results showed that NT increased microbial activity and that soil enzyme activity is a sensitive indicator of alteration soil quality by management.

Elcio Liborio, Balota; Miriam, Kanashiro; Arnaldo, Colozzi Filho; Diva Souza, Andrade; Richard Peter, Dick.

2004-12-01

111

Crop systems biology : an approach to connect functional genomics with crop modelling  

OpenAIRE

The response of the whole crop to environmental conditions is a critical factor in agriculture. It can only be understood if the organization of the crop system is taken into account. A popular view in modern science is that genomics (and other `omics¿) will provide knowledge and tools to allow the characteristics of the crop to be altered for improved actual and potential crop yields, increased resource use efficiency and enhanced crop system health. As a result of this view, (molecular) pl...

Yin, X.; Struik, P. C.

2007-01-01

112

EFFECT OF CROP ROTATION AND LONG TERM FERTILIZATION ON THE CARBON AND GLOMALIN CONTENT IN THE SOIL  

Directory of Open Access Journals (Sweden)

Full Text Available The research was performed on the basis of soil samples taken from a multi-year long fertilization experiment carried out in Skierniewice. The source of samples was soil under potato and rye cultivated in monoculture and in the 5-fields rotation system. The following combinations of fertilization were concerned: Ca, NPK and CaNPK (doses since 1976: 1.6 t·ha-1 CaO every 4 years in monoculture and 2 t·ha-1 CaO every 5 years in crop rotation, 90 kg·ha-1 N, 26 kg·ha-1 P, 91 kg·ha-1 K. Laboratory analyzes involved determination of total organic carbon (TOC and glomalin operationally described as a total glomalin related soil protein (TGRSP. It was found that regardless of cultivated plants and the method of fertilization, only cultivation system such as rotation and monoculture significantly influenced the content of TGRSP. TOC was significantly influenced by interaction between species of cultivated plant and the system of cultivation. The analyzed factors within the method of cultivation (monoculture and crop rotation did not influence significantly the TGRSP content while cultivated plant species, in monoculture, significantly influenced on TOC content. There was also noted positive correlation (r = 0.72 between TGRSP and TOC.

Piotr WOJEWÓDZKI

2012-12-01

113

Effects of grass-clover management and cover crops on nitrogen cycling and nitrous oxide emissions in a stockless organic crop rotation  

DEFF Research Database (Denmark)

Nitrogen (N) supply in stockless organic farming may be improved through use of grass-clover for anaerobic digestion, producing biogas and digested manure for use as fertilizer in the crop rotation. We studied the effects of grass-clover management on N cycling, nitrous oxide (N2O) emissions and cash-crop yields in an organic arable crop rotation on a sandy loam soil in a cool temperate climate. The four-course crop rotation included spring barley (with undersown grass-clover), grass-clover, potato and winter wheat (with undersown cover crop). Two fertilization treatments were compared: “?M” where plant material from grass-clover cuts was left in the field to decompose and no fertilizer or manure was applied to any crop in the rotation; and “+M” where plant material from grass-clover cuts was harvested and equivalent amounts of N in digested manure used for fertilization of cash crops in the rotation (spring barley, potato and winter wheat); actual digestion of grass-clover cuttings was not possible, instead digested pig manure was used as substitute for digested grass-clover. Nitrous oxide fluxes were monitored between April 2008 and May 2009. In general, application of digested manure had little or no effect on N2O emissions. Periods of high N2O emissions coincided with cover crop and grass-clover residue turnover, with little added effect of digested manure application. Annual N2O emissions did not vary between fertilization treatments, but the +M treatment had cash crop dry matter yields that were 14% higher than in the ?M treatment, and cash crop N yields were increased by 40%. The results show that reallocation of nutrients from grass-clover to cash crops following anaerobic digestion can help solve problems with low N availability. However, issues remain regarding N2O from cover crops and grass-clover in spring.

Brozyna, Michal Adam; Petersen, SØren O

2013-01-01

114

Self-seeding small grain cover crops in a soybean-corn rotation  

Science.gov (United States)

Cover crops provide environmental benefits, yet adoption in agronomic farming systems is low. Winter rye (Secale cereale L.), wheat (Triticum aestivum L.), and triticale (X Triticosecale Wittmack) were used to develop self-seeding cover crop systems in a soybean [Glycine max (L.) Merr.]-corn (Zea m...

115

Soil properties, crop production and greenhouse gas emissions from organic and inorganic fertilizer-based arable cropping systems  

DEFF Research Database (Denmark)

Organic and conventional farming practices differ in the use of several management strategies, including use of catch crops, green manure, and fertilization, which may influence soil properties, greenhouse gas emissions and productivity of agroecosystems. An 11-yr-old field experiment on a sandy loam soil in Denmark was used to compare several crop rotations with respect to a range of physical, chemical and biological characteristics related to carbon (C) and nitrogen (N) flows. Four organic rotations and an inorganic fertilizer-based system were selected to evaluate effects of fertilizer type, catch crops, of grass-clover used as green manure, and of animal manure application. Soil was sampled from winter wheat and spring barley plots on 19 September 2007, 14 April 2008 and 22 September 2008, i.e. before, during, and after the growth season. The soils were analyzed for multiple attributes: total soil organic carbon (SOC), total N, microbial biomass N (MBN), potentially mineralizable N (PMN), and levels of potential ammonium oxidation (PAO) and denitrifying enzyme activity (DEA). In situ measurements of soil heterotrophic carbon dioxide (CO2) respiration and nitrous oxide emissions were conducted in plots with winter wheat. In April 2008, prior to field operations, intact soil cores were collected at two depths (0–5 and 5–10 cm) in plots under winter wheat. Water retention characteristics of each core were determined and used to calculate relative gas diffusivity (DP/Do). Finally, crop growth was monitored and grain yields measured at harvest maturity. The different management strategies between 1997 and 2007 led to soil carbon inputs that were on average 18–68% and 32–91% higher in the organic than inorganic fertilizer-based rotations for the sampled winter wheat and spring barley crops, respectively. Nevertheless, SOC levels in 2008 were similar across systems. The cumulative soil respiration for the period February to August 2008 ranged between 2 and 3 t CO2–C ha-1 and was correlated (r = 0.95) with average C inputs. In the organic cropping systems, pig slurry application and inclusion of catch crops generally increased soil respiration, PMN and PAO. At field capacity, relative gas diffusivity at 0–5 cm depth was >50% higher in the organic than the inorganic fertilizer-based system (P < 0.05). Crop yields in 2008 were generally lower in the low-input organic rotations than in the high-input inorganic fertilizer-based system; only spring barley in rotations with pig slurry application and incorporation of a catch crop prior to sowing obtained grain yields similar to levels achieved in the system where inorganic fertilizer was applied. These results suggest that within organic cropping systems, both microbial activity and crop yields could be enhanced through inclusion of catch crops. However, the timing of catch crop incorporation is critical.

Chirinda, Ngonidzashe; Olesen, JØrgen Eivind

2010-01-01

116

Biogas production from catch crops : Evaluation of biomass yield and methane potential of catch crops in organic crop rotations  

DEFF Research Database (Denmark)

Manure-based biogas plants in Denmark are dependent on high yielding biomass feedstock in order to secure economically feasible operation. The aim of this study was to investigate the potential of ten different catch crop species or mixtures as feedstock for biogas production in co-digestion with manure. The biomass yield per hectare and the specific methane yield of the catch crops in two different locations, namely Holstebro and Aabenraa, were investigated. The volatile solids (VS) yield per hectare was notably influenced by the differences in climate and soil conditions between the locations, being in the ranges of 1.4–3.0 t ha?1 and 0.3–1.7 t ha?1 for Holstebro and Aabenraa, respectively. Specific methane yields were in the range of 229–450 m3 t?1 of VS. Methane yields per hectare of up to 800 m3 ha?1 were obtained, making catch crops a promising source of feedstock for manure-based biogas plants in Denmark since this biomass is not competing with food/feed production.

Molinuevo-Salces, Beatriz; Larsen, SØren U.

2013-01-01

117

Variabilidade espacial de atributos do solo em sistema de semeadura direta com rotação de culturas no cerrado brasileiro / Spatial variability of soil attributes in no a no-tillage system with crop rotation in the Brazilian savannah  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O presente estudo objetivou analisar a variabilidade espacial dos atributos químicos e da textura de um Latossolo Vermelho distroférrico. A propriedade onde o estudo foi realizado localiza-se no município de Sidrolândia (MS) e produz soja, milho e algodão, adotando rotação de culturas e o sistema de [...] plantio direto. Em uma área experimental de aproximadamente 90 hectares foi amostrado solo em 181 pontos georeferenciados. As amostras foram compostas por quatro amostras simples, representativas da profundidade de 0,00-0,20 m. Foram mensurados os atributos químicos e a textura do solo. Realizou-se, inicialmente, análise de discrepantes e, posteriormente, análise descritiva e geoestatística para caracterizar as amostras e identificar a dependência espacial dos atributos estudados. Não foi detectada dependência espacial para os atributos acidez ativa em água, alumínio, acidez potencial, saturação por bases e matéria orgânica. As melhores estimativas de valores para locais não amostrados foram observadas para os atributos físicos do solo, os quais apresentaram os melhores parâmetros de ajuste dos variogramas e da validação cruzada. As técnicas de geoestatística utilizadas possibilitaram o ajuste dos modelos teóricos que melhor representaram a semivariância experimental, possibilitando assim a construção de mapas temáticos da distribuição espacial dos valores dos atributos do solo estudado. Abstract in english This study aimed to analyze the spatial variability of the chemical attributes and texture of a red latosol. The study was carried out on a property in the town of Sidrolândia, Matto Grosso do Sul, which produces soybeans, corn and cotton, using crop rotation and a no-tillage system. In an experimen [...] tal area of approximately 90 hectares, samples were taken of the soil at 181 geo-referenced points. The samples were each composed of four single samples, representing depths of from 0 to 0.2 m. The chemical and texture of the soil were measured. Initially a discrepancy analysis was performed followed by descriptive and geostatistical analyses, to characterize the samples and identify the spatial dependence of the attributes studied. No spatial dependence was detected for the attributes: active water acidity, aluminum, potential acidity, base saturation and organic matter. The best estimates of values for non-sampled locations were observed for the physical properties of the soil, which presented parameters which best fit the variograms and cross-validation. The geostatistical techniques used allowed adjustment of the theoretical models that best represented the experimental semivariance, thus enabling the construction of thematic maps of spatial distribution for the values of the attributes of the studied soil.

Eduardo Leonel, Bottega; Daniel Marçal de, Queiroz; Francisco de Assis de Carvalho, Pinto; Cristiano Márcio Alves de, Souza.

2013-03-01

118

Grass-clover undersowing affects nitrogen dynamics in a grain legume-cereal arable cropping system  

DEFF Research Database (Denmark)

A field experiment was carried out in an arable organic cropping system and included a sequence with sole cropped fababean (Vicia faba L), lupin (Lupinus angustifolius L), pea (Pisum sativum L), oat (Avena sativa L) and pea-oat intercropping with or without an undersown perennial ryegrass (Lolium perenne L) - white clover (Trifolium repens L) catch crop followed by a first crop of spring wheat (Triticum aestivum L) and second crop of winter triticale (Triticale hexaploide L). The rotation sequence was repeated twice. Natural N-15 abundance techniques were used to determine grain legume N-2 fixation and N-15 labeling technique to determine the fate of pea and oat residue N recovery in the subsequent crop. The subsequent spring wheat and winter triticale crop yields were not significantly affected by the previous main crop, but a significant effect of catch crop undersowing was observed. A higher soil mineral N content in the soil profile without undersown grass-clover increased the spring wheat yield. This effect was circumvented in the subsequent winter triticale, where yields in the treatments with catch crops undersown were significantly greater. The grass-clover catch crop after grain legumes had a higher grass proportion before incorporation as compared to grass-clover after oat, which had the greatest clover proportion. The dynamic response of interspecific interactions in the catch crop to the soil mineral N levels is moderating the preceding effect of main crops in the subsequent cereal - and sometimes to a higher degree than the main crop effect. For research involving rotation principles it is recommended to evaluate cumulative effects over several years and not only single seasons.

Hauggaard-Nielsen, Henrik; Mundus, Simon

2012-01-01

119

Grass-clover undersowing affects nitrogen dynamics in a grain legume–cereal arable cropping system  

DEFF Research Database (Denmark)

A field experiment was carried out in an arable organic cropping system and included a sequence with sole cropped fababean (Vicia faba L.), lupin (Lupinus angustifolius L.), pea (Pisum sativum L.), oat (Avena sativa L.) and pea–oat intercropping with or without an undersown perennial ryegrass (Lolium perenne L.) – white clover (Trifolium repens L.) catch crop followed by a first crop of spring wheat (Triticum aestivum L.) and second crop of winter triticale (Triticale hexaploide L.). The rotation sequence was repeated twice. Natural 15N abundance techniques were used to determine grain legume N2 fixation and 15N labeling technique to determine the fate of pea and oat residue N recovery in the subsequent crop. The subsequent spring wheat and winter triticale crop yields were not significantly affected by the previous main crop, but a significant effect of catch crop undersowing was observed. A higher soil mineral N content in the soil profile without undersown grass-clover increased the spring wheat yield. This effect was circumvented in the subsequent winter triticale, where yields in the treatments with catch crops undersown were significantly greater. The grass-clover catch crop after grain legumes had a higher grass proportion before incorporation as compared to grass-clover after oat, which had the greatest clover proportion. The dynamic response of interspecific interactions in the catch crop to the soil mineral N levels is moderating the preceding effect of main crops in the subsequent cereal – and sometimes to a higher degree than the main crop effect. For research involving rotation principles it is recommended to evaluate cumulative effects over several years and not only single seasons.

Hauggaard-Nielsen, Henrik; Mundus, Simon

2012-01-01

120

Soil respiration in cucumber field under crop rotation in solar greenhouse  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Crop residues are the primary source of carbon input in the soil carbon pool. Crop rotation can impact the plant biomass returned to the soil, and influence soil respiration. To study the effect of previous crops on soil respiration in cucumber (Cucumis statirus L.) fields in solar greenhouses, soil [...] respiration, plant height, leaf area and yield were measured during the growing season (from the end of Sept to the beginning of Jun the following year) from 2007 to 2010. The cucumber was grown following fallow (CK), kidney bean (KB), cowpea (CP), maize for green manure (MGM), black bean for green manure (BGM), tomato (TM), bok choy (BC). As compared with CK, KB, CP, MGM and BGM may increase soil respiration, while TM and BC may decrease soil respiration at full fruit stage in cucumber fields. Thus attention to the previous crop arrangement is a possible way of mitigating soil respiration in vegetable fields. Plant height, leaf area and yield had similar variation trends under seven previous crop treatments. The ratio of yield to soil respiration revealed that MGM is the crop of choice previous to cucumber when compared with CK, KB, CP, BGM, TM and BC.

Yinli, Liang; Caihong, Bai; Lan, Mu; Maojuan, Zhou.

2014-08-01

121

Energy Product Options for Eucalyptus Species Grown as Short Rotation Woody Crops  

Directory of Open Access Journals (Sweden)

Full Text Available Eucalyptus species are native to Australia but grown extensively worldwide as short rotation hardwoods for a variety of products and as ornamentals. We describe their general importance with specific emphasis on existing and emerging markets as energy products and the potential to maximize their productivity as short rotation woody crops. Using experience in Florida USA and similar locations, we document their current energy applications and assess their productivity as short-term and likely long-term energy and related products.

Jerrold E. Winandy

2008-07-01

122

DYNAMIC CROPPING SYSTEMS INFLUENCE ON SOIL BIOCHEMISTRY  

Science.gov (United States)

In the Northern Great Plains, more intensive, diverse cropping systems have been developed as a means to improve soil and water conservation in the region. A no-till field research project was conducted near Mandan, ND on a Wilton-Temvik silt loam (fine-silty, mixed, superactive, frigid Pachic and T...

123

AGRONOMY AND PHYSIOLOGY OF TROPICAL COVER CROPS  

Science.gov (United States)

Cover crops are important components of a sustainable crop production system. They can be planted with plantation crops such as cacao, coffee, banana, rubber and oil palm or in rotation with cash crops. Their use in a cropping system is mainly beneficial for soil and water conservation, recycling of...

124

The consequent influence of crop rotation and six-year-long spring barley monoculture on yields and weed infestation of white mustard and oats  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was conducted in the years 2007- 2008, after 6-year-long experiments in the cultivation of spring barley in a crop rotation system and in monoculture. The other experimental factor was the spring barley protection method. Intensive protection involved comprehensive treatment of barley (in-crop harrowing, seed dressing, application of herbicides, fungicides, a retardant and an insecticide. Extensive protection consisted only in in-crop harrowing, without the application of crop protection agents, except for seed dressing. The above mentioned factors formed the background for the study on the cultivation of white mustard and oats, as phytosanitary species, in successive years. In the test plants, no mineral fertilization and crop protection were applied. Such agricultural method enabled an objective assessment of the consequent effect of monoculture, crop rotation and crop treatments. A hypothesis was made that the cultivation of the phytosanitary plants in the stand after 6-year-long barley monoculture would allow obtaining the level of yields and weed infestation similar to those of the crop rotation treatments. It was also assumed that the cultivation of white mustard and oats would eliminate differences in plant productivity caused by the negative influence of extensive protection. It was proved that the cultivation of the phytosanitary plants eliminated the negative influence of monoculture on the level of their yields and weed infestation. However, the test plants did not compensate negative consequences of extensive protection. In spite of this, white mustard and oats effectively competed with weeds, and the number and weight of weeds in a crop canopy did not cause a dramatic decline in yields. In the test plant canopy, the following short-lived weeds were predominant: Chenopodium album, Galinsoga parviflora, Echinochloa crus-galli. The absence of herbicide application resulted in the compensation of perennial species: Elymus repens and Cirsium arvense.

Cezary Kwiatkowski

2009-12-01

125

Short-rotation woody-crops program. Quarterly progress report for period ending August 31, 1981  

Energy Technology Data Exchange (ETDEWEB)

Progress of twenty-one projects in the Short Rotation Woody Crops Program is summarized for the period June 1 through August 31, 1981. Individual quarterly reports included from each of the projects discuss accomplishments within specific project objectives and identify recent papers and publications resulting from the research. The major program activities are species screening and genetic selection, stand establishment and cultural treatment, and harvest, collection, transportation, and storage.

Cushman, J.H.; Ranney, J.W.

1982-04-01

126

Modelling the crop: from system dynamics to systems biology  

OpenAIRE

There is strong interplant competition in a crop stand for various limiting resources, resulting in complex compensation and regulation mechanisms along the developmental cascade of the whole crop. Despite decades-long use of principles in system dynamics (e.g. feedback control), current crop models often contain many empirical elements, and model parameters may have little biological meaning. Building on the experience in designing the relatively new model GECROS, we believe models can be ma...

Yin, X.; Struik, P. C.

2010-01-01

127

Controle de doenças de plantas pela rotação de culturas / Control of plant disease by crop rotation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Esta revisão aborda a importância da escolha e da adoção de práticas culturais e seus reflexos na intensidade de doenças de plantas. São apresentados conceitos básicos referente ao tema e os de rotação e monocultura. Discutem-se os princípios ou fundamentos e potencialidade do uso da rotação e do ma [...] nejo integrado de doenças, as consequências da nutrição de fitopatógenos, dos eventos biológicos ocorrentes nos restos culturais, as características dos fitopatógenos potencialmente controláveis e dos não controláveis pela rotação. Abstract in english This review deals with the importance of the selection and use of cultural practices and their reflex in plant disease intensity. Basic concepts related to the subject and crop rotation and monoculture are presented. Principles fundaments are discussed in addition to, the potential use of crop rotat [...] ion integrated disease management. The consequences of plant pathogens nutrition, biological events in crop residues, characteristics of phytopathogens potentially controlled and not controlled by rotation are also dealt.

Erlei Melo, Reis; Ricardo Trezzi, Casa; Vânia, Bianchin.

2011-09-01

128

Short-rotation woody crops for bioenergy and biofuels applications  

OpenAIRE

Purpose-grown trees will be part of the bioenergy solution in the United States, especially in the Southeast where plantation forestry is prevalent and economically important. Trees provide a “living biomass inventory” with existing end-use markets and associated infrastructure, unlike other biomass species such as perennial grasses. The economic feasibility of utilizing tree biomass is improved by increasing productivity through alternative silvicultural systems, improved breeding and bi...

Hinchee, Maud; Rottmann, William; Mullinax, Lauren; Zhang, Chunsheng; Chang, Shujun; Cunningham, Michael; Pearson, Leslie; Nehra, Narender

2009-01-01

129

Short-rotation woody crops for bioenergy and biofuels applications.  

Science.gov (United States)

Purpose-grown trees will be part of the bioenergy solution in the United States, especially in the Southeast where plantation forestry is prevalent and economically important. Trees provide a "living biomass inventory" with existing end-use markets and associated infrastructure, unlike other biomass species such as perennial grasses. The economic feasibility of utilizing tree biomass is improved by increasing productivity through alternative silvicultural systems, improved breeding and biotechnology. Traditional breeding and selection, as well as the introduction of genes for improved growth and stress tolerance, have enabled high growth rates and improved site adaptability in trees grown for industrial applications. An example is the biotechnology-aided improvement of a highly productive tropical Eucalyptus hybrid, Eucalyptus grandis x Eucalyptus urophylla. This tree has acquired freeze tolerance by the introduction of a plant transcription factor that up-regulates the cold-response pathways and makes possible commercial plantings in the Southeastern United States. Transgenic trees with reduced lignin, modified lignin, or increased cellulose and hemicellulose will improve the efficiency of feedstock conversion into biofuels. Reduced lignin trees have been shown to improve efficiency in the pre-treatment step utilized in fermentation systems for biofuels production from lignocellulosics. For systems in which thermochemical or gasification approaches are utilized, increased density will be an important trait, while increased lignin might be a desired trait for direct firing or co-firing of wood for energy. Trees developed through biotechnology, like all transgenic plants, need to go through the regulatory process, which involves biosafety and risk assessment analyses prior to commercialization. PMID:19936031

Hinchee, Maud; Rottmann, William; Mullinax, Lauren; Zhang, Chunsheng; Chang, Shujun; Cunningham, Michael; Pearson, Leslie; Nehra, Narender

2009-12-01

130

Eco-efficient approaches to land management: a case for increased integration of crop and animal production systems  

OpenAIRE

Eco-efficiency is concerned with the efficient and sustainable use of resources in farm production and land management. It can be increased either by altering the management of individual crop and livestock enterprises or by altering the land-use system. This paper concentrates on the effects of crop sequence and rotation on soil fertility and nutrient use efficiency. The potential importance of mixed farming involving both crops and livestock is stressed, particularly when the systems incorp...

Wilkins, R. J.

2007-01-01

131

Biomass production of short-rotation bioenergy hardwood plantations affected by cover crops  

Energy Technology Data Exchange (ETDEWEB)

Effects of varying strip widths of four species of cover crops on the growth of sweetgum (Liquidambar styraciflua L.) seedlings planted as a short-rotation bioenergy woody crop were studied. Ryegrass (Lolium multiflorum L. a winter annual grass); tall fescue (Festuca arundinacea Schreb a cool season perennial grass); crimson clover (Trifloium incarnatum L. a winter annual legume); and Interstate sericea lespedeza (Lespedeza cuneata (Dumont) G. Don. a summer growing perennial legume), were planted using two different strip widths (1.22 and 2.44 m) between trees on a 1.5 x 3 m spacing. The control had no competition. Height, ground-line diameter and volume index of trees were determined on a monthly basis. Lespedeza and tall fescue significantly reduced ground line diameter compared to ryegrass and the control. Crimson clover significantly reduced ground line diameter compared to the control and volume index more than ryegrass and the control. During the first two growing seasons, there was no benefit from legumes as a cover crop over grasses. All cover crops except rye grass significantly reduced sweetgum biomass compared to control. The results indicate that cover crops lespedeza, tall fescue, crimson clover and ryegrass reduced biomass by approximately 41%, 37%, 27% and 15%, respectively, compared to the control. The 2.44 m strip width reduced sweetgum growth 40% relative to the control vs. 20% with the 1.22 m strip width. Strip width had a greater impact on diameter and volume index than height. (Author)

Malik, R.K.; Green, T.H.; Brown, G.F.; Beyl, C.A.; Sistani, K.R.; Mays, D.A. [Alabama A and M Univ., Normal, AL (United States). Center for Forestry and Ecology

2001-07-01

132

Thermocapillary Instabilities with System Rotation.  

Science.gov (United States)

Coriolis effects on the instabilities of dynamic thermocapillary liquid layers(Smith M.K. & Davis S.H., JFM 132, 119-144, 1983.) are investigated. The basic steady, linear and return, shear flows driven by imposed temperature gradients in the (1,0,0) direction are modified due to system rotation with vector (?_1,?_2,?_3) and a shear flow is generated in the (0,1,0) direction if ?3 is not zero. Linear stability of the basic states is determined by the Marangoni (M), Prandtl (P), Biot, and a vector Taylor number (? ). In addition, critical states are characterized by wavenumbers ? and ?, and a phase speed. A pseudospectral method coupled with a minimization scheme is used to determine the preferred form of convection. The influence of rotation is found to be dramatic. For example, the hydrothermal waves preferred in the return flow model with no rotation are replaced by stationary modes at much lower values of M in a manner strongly dependent on P and the rotation vector. These effects occur at values of ( ? ) typical of the microgravity environment of an orbiting space laboratory and thus must be included in designing future space experiments.

Zebib, A.

1996-11-01

133

Nonlocal Electrodynamics of Rotating Systems  

OpenAIRE

The nonlocal electrodynamics of uniformly rotating systems is presented and its predictions are discussed. In this case, due to paucity of experimental data, the nonlocal theory cannot be directly confronted with observation at present. The approach adopted here is therefore based on the correspondence principle: the nonrelativistic quantum physics of electrons in circular "orbits" is studied. The helicity dependence of the photoeffect from the circular states of atomic hydr...

Mashhoon, Bahram

2005-01-01

134

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

Energy Technology Data Exchange (ETDEWEB)

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 at the study site, may better perform on marginal sites. Switchgrass is an example of the need to grow site-adapted energy crops. The annual energy crop maize required the highest input, but at the same time yielded the most. The two crop rotation systems did not differ in yield and energy input, but the system with no-till may be more environmentally benign as it has the potential to sequester carbon. The objective of Paper II was the optimization of crop cultivation through the differentiation of input parameters to enhance the quality of the energy crop triticale, without influencing the biomass yield. The intention was to minimize the content of combustion-disturbing elements (potassium and chlorine) and the ash residue of both aboveground plant parts (grain and straw). It was done through different straw and potassium fertilizer treatments. It could be shown that the removal of straw from the previously cultivated crop and no additional potassium fertilizer could reduce the amount of combustion-disturbing elements. A high influence must also be expected from site and weather conditions. Papers III to V address the supply of different high quality biomasses, with the focus on maize for anaerobic digestion. The objective of Paper III was the assessment of the requirements of biogas plants and biomass for anaerobic digestion. It introduces potential energy crops, along with their advantages and disadvantages. Alongside maize, many other biomass types, which are preserved as silage and are high in carbohydrates and low in lignocelluloses, can be anaerobically digested. The development of potential site-specific crop rotation systems for biomass production are discussed. The objective of Papers IV and V was the identification of suitable biomass and production systems for the anaerobic digestion. The focus lay on the determination of (i) suitable energy maize varieties for Central Europe, (ii) optimal growth periods of energy crops, (iii) the influence of crop management on quality parameters and (iv) environmentally benign crop rotation systems. Differently mat

Boehmel, Ute Constanze

2007-07-18

135

Role of nematodes, nematicides, and crop rotation on the productivity and quality of potato, sweet potato, peanut, and grain sorghum.  

Science.gov (United States)

The objective of this experiment was to determine the effects of fenamiphos 15G and short-cycle potato (PO)-sweet potato (SP) grown continuously and in rotation with peanut (PE)-grain sorghum (GS) on yield, crop quality, and mixed nematode population densities of Meloidogyne arenaria, M. hapla, M. incognita, and Mesocriconema ornatum. Greater root-gall indices and damage by M. hapla and M. incognita occurred on potato than other crops. Most crop yields were higher and root-gall indices lower from fenamiphos-treated plots than untreated plots. The total yield of potato in the PO-SP and PO-SP-PE-GS sequences increased from 1983 to 1985 in plots infested with M. hapla or M. arenaria and M. incognita in combination and decreased in 1986 to 1987 when root-knot nematode populations shifted to M. incognita. The total yields of sweet potato in the PO-SP-PE-GS sequence were similar in 1983 and 1985, and declined each year in the PO-SP sequence as a consequence of M. incognita population density increase in the soil. Yield of peanut from soil infested with M. hapla increased 82% in fenamiphos-treated plots compared to untreated plots. Fenamiphos treatment increased yield of grain sorghum from 5% to 45% over untreated controls. The declining yields of potato and sweet potato observed with both the PO-SP and PO-SP-PE-GS sequences indicate that these crop systems should not be used longer than 3 years in soil infested with M. incognita, M. arenaria, or M. hapla. Under these conditions, these two cropping systems promote a population shift in favor of M. incognita, which is more damaging to potato and sweet potato than M. arenaria and M. hapla. PMID:19277157

Johnson, A W; Dowler, C C; Glaze, N C; Handoo, Z A

1996-09-01

136

Nitrous oxide and carbon dioxide emissions from monoculture and rotational cropping of corn, soybean and winter wheat  

International Nuclear Information System (INIS)

Nitrous oxide (N2O) and carbon dioxide (CO2) emissions from agricultural soils are influenced by different types of crops, the amounts and types of nitrogen fertilizers used, and the soil and climatic conditions under which the crops are grown. Crop rotation also has an impact on N2O emissions, as the crop residues used to supply soluble carbon to soil biota often differ from the crops being grown. This study compared the influence of crops and residues from preceding crops on N2O and CO2 emissions from monoculture crops of soybeans, corn, and winter wheat at a site in Ontario. The phases of different rotations were compared with 2- and 3-year crop rotations. Results of the study showed that N2O emissions were approximately 3.1 to 5.1 times higher in monoculture corn than levels observed in winter wheat or soybean crops. When corn followed corn, average N2O emissions twice as high as when corn followed soybeans, and 65 per cent higher than when corn followed winter wheat. The higher levels of both N2O and CO2 were attributed to higher inorganic nitrogen (N) application rates in corn crops. In the corn phase, CO2 levels were higher when the preceding crop was winter wheat. It was concluded that N2O and CO2 emissions from agricultural fields are influenced by both current and preceding crops, a fact which should be considered and accounted which should be considered and accounted for in estimates and forecasts of agricultural greenhouse gas (GHG) emissions. 21 refs., 3 tabs., 10 figs

137

Universal Entropy Bound for Rotating Systems  

OpenAIRE

We conjecture a universal upper bound to the entropy of a rotating system. The entropy bound follows from application of the generalized second law of thermodynamics to an idealized gedanken experiment in which an entropy-bearing rotating system falls into a black hole. This bound is stronger than the Bekenstein entropy bound for non-rotating systems.

Hod, Shahar

1999-01-01

138

Comportamento de Sternechus subsignatus (Boheman) em dez espécies vegetais de verão para rotação de culturas ou cultura armadilha no plantio direto / Sternechus subsignatus (Boheman) behaviour in ten summer rotation specles and trapping crops for no-tillage system  

Scientific Electronic Library Online (English)

Full Text Available O desenvolvimento de Sternechus subsignatus (Boheman) (Coleoptera: Curculionidae) foi avaliado em dez espécies vegetais sob condições naturais num solo manejado há três anos no sistema de plantio direto corn soja cultivada no verão. Foram observados o número de plantas atacadas, a oviposição, o núrn [...] ero e peso de larvas, o número de larvas hibernantes no solo e o número de adultos emergidos. O inseto se reproduziu e desenvolveu ern feijão (Phaseolus vulgaris L) guandu anão (Cajanus cajan L), lab-lab (Dolichos lablab L.) e soja (Glycine max L.) e ao contrário, em crotalária júncea (Crotalaria júncea L). girassol (Helianthus annuus L.), milheto (Pennisetum americanum Leek), milho (Zea mays L), mucuna preta (Stizolobium aterrimum Piper et Tracy) e sorgo (Sorghum bicolor L.) não completou o ciclo de vida. Os resultados indicaram que a cultura do feijão, guandu anão, lab-lab e soja aumentaram a população do inseto. Entretanto, ocorreu redução na população do inseto corn as culturas da crotalária júncea, girassol, milheto, milho, mucuna preta e sorgo. As quatro primeiras espécies são hospedeiras preferenciais, podendo ser usadas como culturas armadilhas e as demais, não são hospedeiras, pois propiciam a diminuição da população do inseto, sendo ideais para uso em sistemas derotação de culturas no verão, em áreas infestadas, para substituir o monocultivo da soja em plantio direto. Abstract in english The development of Sternechus subsignatus (Boheman) (Coleoptera. Curculionidae) was evaluated on ten crop species under natural conditions under no-tillage system for three years and infested with the insect Soybean was the Summer crop continously cultivated in the area. Number of attacked plants, o [...] viposition, number and weight of larvae and number of adults emerged were the parameters evaluated. The insect reproduced and developed in bean (Phaseolus vulgaris L), grandull (Cajanus cajan L.), dolichos (Dolichos lablab L.) and soybean (Glycine max L.) and not in bengal hemp (Crotalaria júncea L ), sunflower (Helianthus annuus L.), millet (Pennisetum americanum Leek), corn (Zea mays L.), black velvet bean (Stizolobium aterrimum Piper et Tracy) and sorghum (Sorghum bicolor L.) did not complete lhe life cycle Results indicated that P. vulgaris, C. cajan, D. lablab and G. max increased insect populatron but, a reduction was observed on C. juncea, H. annuus, P. americanum, Z. mays, S. aterrimum and S. bicolor. The first four related species are the preferred hosts and may be used as trap crops. The other six species did not host the insect, decreasing its populations and thus being ideal to be included in Summer crop rotafion systems to subslitute soybean monocropping under no-tillage.

Mauro Tadeu Braga da, Silva.

1997-12-01

139

Refueling system with small diameter rotatable plugs  

International Nuclear Information System (INIS)

This patent describes a liquid-metal fastbreeder nuclear reactor comprising a reactor pressure vessel and closure head therefor, a reactor core barrel disposed within the reactor vessel and enclosing a reactor core having therein a large number of closely spaced fuel assemblies, and the reactor core barrel and the reactor core having an approximately concentric circular cross-sectional configuration with a geometric center in predetermined location within the reactor vessel. The improved refueling system described here comprises: a large controllably rotatable plug means comprising the substantial portion of the closure head, a reactor upper internals structure mounted from the large rotatable plug means. The large rotatable plug means has an approximately circular configuration which approximates the cross-sectional configuration of the reactor core barrel with a center of rotation positioned a first predetermined distance from the geometric center of the reactor core barrel so that the large rotatable plug means rotates eccentrically with respect to the reactor core barrel; a small controllably rotatable plug means affixed to the large rotatable plug means and rotatable with respect thereto. The small rotatable plug means has a center of rotation which is offset a second predetermined distance from the rotational center of the large rotatable plug means so that the small rotatable plug means rotates eccentrically with respect to the large rotatable plug meanst to the large rotatable plug means

140

Population Dynamics of Meloidogyne incognita, M. arenaria,and Other Nematodes and Crop Yields in Rotations of Cotton, Peanut, and Wheat Under Minimum Tillage  

OpenAIRE

Wheat, cotton, and peanut were arranged in three cropping sequences to determine the effects of fenamiphos (6.7 kg a.i./ha) and cropping sequence on nematode population densities and crop yields under conservation tillage and irrigation for 6 years. The cropping sequences included a wheat winter cover crop each year and summer crops of cotton every year, peanut every year, or cotton rotated every other year with peanut. The population densities of Meloidogyne spp. and Helicotylenchus dihyster...

Johnson, A. W.; Dowler, C. C.; Handoo, Z. A.

2000-01-01

141

Rotating fluidized bed gasifier system  

Energy Technology Data Exchange (ETDEWEB)

A rotating fluidized bed gasifier system especially useful in compound engines comprises an annular fluidization chamber containing a bed of carbon containing pulverulent solid materials. The chamber, which is defined by inner and outer spaced apart coaxial, cylindrical, perforated walls, rotates about the longitudinal axis of the cylinders. Steam enters the bed, which is maintained at about 1800/sup 0/ F., through the outer perforated wall and fluidizes the particles. The steam reacts endothermically with the carbon to produce reaction product gas which exits the bed, together with unreacted steam, through the inner perforated wall. In a preferred form of the invention the bed is maintained at approximately 1800/sup 0/ F. By combining a rotating fluidized bed combustor with the gasifier. In this embodiment compressed air and powdered coal enter the bed with the steam through the outer perforated wall. The air reacts exothermically with the fuel within the bed to generate heat for the endothermic steam-carbon reaction and to produce hot combustion gas which exit the bed, together with the reaction product gas, unreacted steam and compressed air, through the inner perforated wall.

Belke, W.H.; Goloff, A.; Grim, G.B.

1981-08-04

142

Characterization of crop rotations in irrigation areas of the Ebro Valley from temporal series of Landsat TM images  

Science.gov (United States)

The present paper presents a method to characterize typical crop rotations from temporal series analysis of land use maps derived from supervised classifications of Landsat TM images. The analysis is based on spatial cross-tabulation of land use maps in raster format. As a case study, a temporal land use map series from 1993 to 2000 of the Flumen irrigation area (Huesca, Spain) was considered. The spatial cross-tabulation analysis between each pair of consecutive land use maps, performed in Idrisi 32, yielded a two dimensional matrix that allowed the identification of the typical crop rotations in the study area. Those are rice - fallow land - rice, sunflower - winter cereals - alfalfa - corn, and others as winter cereal or sunflower - fallow land - corn or alfalfa. Rice appears as a typical crop in this area, in which it is usually associated to salt- and/or sodium-affected soils. Those typical rotations have been also spatially located and represented in a map following the crop changes from one year to another year that are registered in the cross-tabulation images. The method can be useful to identify tendencies in the temporal variation of crop rotations in agricultural areas, and to locate typical areas with salt- and/or sodium-affected soils by mapping rotations in which rice is the main crop.

Martinez-Casasnovas, Jose A.; Martin-Montero, Almudena

2004-02-01

143

Crop yield, root growth, and nutrient dynamics in a conventional and three organic cropping systems with different levels of external inputs and N re-cycling through fertility building crops  

DEFF Research Database (Denmark)

One of the core ideas behind organic production is that cropping systems should be less dependent on import of resources, and minimize negative effects on the surrounding environment compared to conventional production. However, even when clearly complying with regulations for organic production, it is not always obvious that these goals are reached. As an example, strong dependence on import of manure is often seen in current organic production, especially in systems producing high value crops such as vegetable crops. The aim of the present study was to test novel approaches to organic rotations, designed to reduce the reliance on import of external resources significantly. We compared a conventional system (C) and an organic system relying on manure import for soil fertility (O1) to two novel systems (O2 and O3) all based on the same crop rotation. The O2 and O3 systems represented new versions of the organic rotation, both relying on green manures and catch crops grown during the autumn after the maincrop as their main source of soil fertility, and the O3 system further leaving rows of the green manures to grow as intercrops between vegetable rows to improve the conditions for biodiversity and natural pest regulation in the crops. Reliance on resource import to the systems differed, with average annual import of nitrogen fertilizers of 149, 85, 25 and 25 kg N ha-1 in the C, O1, O2 and O3 systems, respectively. As expected, the crop yields were lower in the organic system. It differed strongly among crop species, but on average the organic crops yielded c. 82% of conventional yields in all three organic systems, when calculated based on the area actually grown with the main crops. In the O3 system some of the area of the vegetable fields was allocated to intercrops, so vegetable yields calculated based on total land area was only 63% of conventional yields. Differences in quality parameters of the harvested crops, i.e. nutrient content, dry matter content or damages by pests or diseases were fewand not systematic, whereas clear effects on nutrient balances and nitrogen leaching indicators were found. Root growth of all crops was studied in the C and O2 system, but only few effects of cropping system on root growth was observed. However, the addition of green manures to the systems almost doubled the average soil exploration by active root systems during the rotation from only 21% in C to 38% in O2 when measured to 2.4 m depth. This relates well to the observed differences in subsoil inorganic N content (Ninorg, 1–2 m depth) across the whole rotation (74 and 61 kg N ha-1 in C and O1 vs. only 22 and 21 kg N ha-1 in O2 and O3), indicating a strongly reduced N leaching loss in the two systems based on fertility building crops (green manures and catch crops). In short, the main distinctions were not observed between organic and conventional systems (i.e. C vs. O1, O2 and O3), but between systems based mainly on nutrient import vs. systems based mainly on fertility building crops (C and O1 vs. O2 and O3).

Thorup-Kristensen, Kristian; DresbØll, Dorte Bodin

2012-01-01

144

Cropping system effects on soilborne potato diseases and soil microbial communities  

Science.gov (United States)

Four different potato cropping systems, designed to address specific management goals of soil conservation (SC), soil improvement (SI), disease suppression (DS), and a status quo (SQ) standard rotation control, were evaluated for their effects on soilborne diseases of potato and soil microbial commu...

145

Produção de trigo e triticale em rotações de sequeiro Wheat and triticale in crop rotations  

Directory of Open Access Journals (Sweden)

Full Text Available Apresentam-se os resultados de um ensaio de rotações que decorreu durante dez anos em Vila Real (Trás-os-Montes. O ensaio incluiu a rotação tradicional das condições de sequeiro de Trás-os-Montes, cereal-alqueive (TA, e rotações alternativas susceptíveis de serem adoptadas nestas condições, cereal-leguminosa (TL, cereal-consociação forrageira (TC e cereal-prado de sequeiro (TP. Os cereais das rotações foram o trigo e, posteriormente, o triticale. Determinaram-se e analisaram-se as produções de grão e palha, os teores de nutrientes do grão e da palha e acompanharam-se os parâmetros do solo, pH, matéria orgânica e os teores de P2 O 5, K2 O e bases de troca. Destacam-se alguns resultados importantes, tais como: as produções de grão de cereal das rotações não mostrarem diferenças significativas entre si; a produção de palha da rotação TL ser superior às das restantes; o trigo cultivado após prado de sequeiro não dispensar a adubação azotada; as rotações conduzirem a modificações dos teores de matéria orgânica, cálcio de troca ou do valor do pH do solo, factores a que se deve atender, caso a rotação se prolongue por muitos anos.The results of a field trial of crop rotations conducted over a period of ten years in Vila Real (Northeast Portugal are presented. The rotations tested were cereal-cultivated fallow (TA, traditional in rain-fed conditions of the region, and alternative rotations that could be adopted in these conditions: cereal-grain legume crop (TL, cereal-forage mixture (TC and cereal-rain-fed pasture (TP. The cereals were wheat and, later, triticale. Grain, straw and aerial biomass yields were evaluated together with concentrations of nutrients. The soil parameters studied were pH, organic matter and P 2 O 5, K2O and exchange cations. Wheat straw yield of TL rotation was higher than that of the others. Wheat from TP rotation still requires nitrogen fertilization. The soils of the different rotations registered changes of organic matter, Ca, Mg and pH values, which should be taken into account if these rotations are practised over several years.

Carlos Castro

2008-01-01

146

Produção de trigo e triticale em rotações de sequeiro / Wheat and triticale in crop rotations  

Scientific Electronic Library Online (English)

Full Text Available SciELO Portugal | Language: Portuguese Abstract in portuguese Apresentam-se os resultados de um ensaio de rotações que decorreu durante dez anos em Vila Real (Trás-os-Montes). O ensaio incluiu a rotação tradicional das condições de sequeiro de Trás-os-Montes, cereal-alqueive (TA), e rotações alternativas susceptíveis de serem adoptadas nestas condições, cereal [...] -leguminosa (TL), cereal-consociação forrageira (TC) e cereal-prado de sequeiro (TP). Os cereais das rotações foram o trigo e, posteriormente, o triticale. Determinaram-se e analisaram-se as produções de grão e palha, os teores de nutrientes do grão e da palha e acompanharam-se os parâmetros do solo, pH, matéria orgânica e os teores de P2 O 5, K2 O e bases de troca. Destacam-se alguns resultados importantes, tais como: as produções de grão de cereal das rotações não mostrarem diferenças significativas entre si; a produção de palha da rotação TL ser superior às das restantes; o trigo cultivado após prado de sequeiro não dispensar a adubação azotada; as rotações conduzirem a modificações dos teores de matéria orgânica, cálcio de troca ou do valor do pH do solo, factores a que se deve atender, caso a rotação se prolongue por muitos anos. Abstract in english The results of a field trial of crop rotations conducted over a period of ten years in Vila Real (Northeast Portugal) are presented. The rotations tested were cereal-cultivated fallow (TA), traditional in rain-fed conditions of the region, and alternative rotations that could be adopted in these con [...] ditions: cereal-grain legume crop (TL), cereal-forage mixture (TC) and cereal-rain-fed pasture (TP). The cereals were wheat and, later, triticale. Grain, straw and aerial biomass yields were evaluated together with concentrations of nutrients. The soil parameters studied were pH, organic matter and P 2 O 5, K2O and exchange cations. Wheat straw yield of TL rotation was higher than that of the others. Wheat from TP rotation still requires nitrogen fertilization. The soils of the different rotations registered changes of organic matter, Ca, Mg and pH values, which should be taken into account if these rotations are practised over several years.

Carlos, Castro; João, Coutinho; Nuno, Moreira; António, Crespi.

2008-01-01

147

Improving Resilience of Northern Field Crop Systems Using Inter-Seeded Red Clover: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available In light of the environmental challenges ahead, resilience of the most abundant field crop production systems must be improved to guarantee yield stability with more efficient use of nitrogen inputs, soil and water resources. Along with genetic and agronomic innovations, diversification of northern agro-ecosystems using inter-seeded legumes provides further opportunities to improve land management practices that sustain crop yields and their resilience to biotic and abiotic stresses. Benefits of legume cover crops have been known for decades and red clover (Trifolium pratense is one of the most common and beneficial when frost-seeded under winter wheat in advance of maize in a rotation. However, its use has been declining mostly due to the use of synthetic fertilizers and herbicides, concerns over competition with the main crop and the inability to fully capture red clover benefits due to difficulties in the persistence of uniform stands. In this manuscript, we first review the environmental, agronomic, rotational and economical benefits associated with inter-seeded red clover. Red clover adaptation to a wide array of common wheat-based rotations, its potential to mitigate the effects of land degradation in a changing climate and its integration into sustainable food production systems are discussed. We then identify areas of research with significant potential to impact cropping system profitability and sustainability.

William Deen

2013-02-01

148

Agro-climatic adaptation of cropping systems under climate change in Shanghai  

Science.gov (United States)

Climate change affects the heat and water resources required by agriculture, thus shifting cropping rotation and intensity. Shanghai is located in the Taihu Lake basin, a transition zone for various cropping systems. In the basin, moderate climate changes can cause major shifts in cropping intensity and rotation. In the present study, we integrated observational climate data, one regional climate model, land use maps, and agricultural statistics to analyze the relationship between heat resources and multi-cropping potential in Shanghai. The results of agro-climatic assessment showed that climate change over the past 50 years has significantly enhanced regional agroclimatic resources, rendering a shift from double cropping to triple cropping possible. However, a downward trend is evident in the actual multi-cropping index, caused principally by the increasing costs of farming and limitations in the supply of labor. We argue that improving the utilization rate of the enhanced agro-climatic resources is possible by introducing new combinations of cultivars, adopting more laborsaving technologies, and providing incentives to farmers.

Liang, Zhuoran; Gu, Tingting; Tian, Zhan; Zhong, Honglin; Liang, Yuqi

2015-03-01

149

ECONOMIC AND RISK ANALYSIS OF SUSTAINABLE CROPPING SYSTEMS  

Science.gov (United States)

This paper evaluates the profitability and economic risks associated with six cropping systems for the Sustainable Agriculture Demonstration site at the Beltsville Agricultural Research Center in Maryland. The six systems are: (1) no-tillage system, (2) corn/soybean system, (3) cover crop system, (...

150

Phosphorus and potassium balance in soil under crop rotation and fertilizationBalanço de fósforo e potássio no solo sob rotação de culturas e adubações  

Directory of Open Access Journals (Sweden)

Full Text Available The use of crop rotation and manure application can provide sustainability for an agricultural production system by improving soil quality and increasing nutrient use efficiency. This study aimed to evaluate the effect of mineral, organic and mineral+organic fertilization on grain yield and on soil phosphorus and potassium balance, in two crop systems under no-till, with and without rotation of cover crops. The experiment was carried out from 2006 to 2008 on a clayey Rhodic Hapludox in Marechal Cândido Rondon, Paraná State, Brazil. The cropping sequence in the rotation system involving cover crops was black oat + hairy vetch + forage turnip/corn/pigeon pea/wheat/mucuna + brachiaria + sunn hemp, and in the succession system was wheat/corn/wheat/soybean. Organic and mineral+organic fertilizations consisted of the application of solely manure and manure combined with mineral fertilizer, respectively. Soil P and K balances were calculated after the second year of the experiment, up to a depth of 0.40 m. First year corn yields were higher in the crop succession system accompanied by mineral fertilization. In the second year, wheat and soybean yield did not vary between crop systems and nutrient sources, demonstrating the residual effect of crop rotation and manure use. Crop rotation with cover crops resulted in an increase in soil K levels by promoting the recycling of this nutrient in the soil. In both crop systems, the application of mineral and organic fertilizers – either in isolation or in combination – resulted in a negative soil P and K balance in the short term. This represents a threat to the sustainability of the agricultural production system in the long term, due to the depletion of soil nutrient reserves. A utilização de rotação de culturas e a aplicação de esterco pode conferir sustentabilidade ao sistema de produção agrícola, por melhorar a qualidade do solo e aumentar a eficiência de uso de nutrientes. O objetivo deste trabalho foi avaliar o efeito da adubação mineral, orgânica e mineral+orgânica na produtividade de grãos e no balanço de fósforo e de potássio no solo em dois sistemas de culturas sob plantio direto, com e sem rotação de plantas de cobertura. O experimento foi conduzido em Marechal Cândido Rondon, Paraná, Brasil, de 2006 a 2008, em um Latossolo Vermelho. A sequência de culturas no sistema em rotação com plantas de cobertura foi aveia preta + ervilhaca + nabo/milho/guandu/trigo/mucuna + braquiária + crotalária / milho, e no sistema em sucessão foi trigo/milho/trigo/soja/milho. As adubações, orgânica e mineral+orgânica consistiram, respectivamente, da aplicação de esterco e de esterco combinado com fertilizante mineral. O balanço de P e de K no solo foi avaliado, após o segundo ano de condução do experimento, na camada de 0,0–0,40 m de profundidade. A produtividade do milho, no primeiro ano, foi superior na sucessão de culturas e na adubação mineral. No segundo ano, a produtividade de trigo e de soja não se alterou entre os sistemas de culturas e fontes de nutrientes, o que demonstra o efeito residual da rotação de culturas e do uso de esterco. Rotação de culturas com plantas de cobertura proporcionou aumento na quantidade de K no solo, por favorecer o processo de ciclagem deste nutriente do solo. Ambos os sistemas de culturas associados à aplicação fertilizante mineral e esterco de forma isolada ou combinada resultaram em saldo negativo do balanço de P e K no solo em curto prazo, representando uma ameaça para a sustentabilidade do sistema de produção em longo prazo, devido o esgotamento das reservas desses nutrientes do solo.

Fabio Steiner

2012-12-01

151

Farm-scale costs and returns for second generation bioenergy cropping systems in the US Corn Belt  

International Nuclear Information System (INIS)

While grain crops are meeting much of the initial need for biofuels in the US, cellulosic or second generation (2G) materials are mandated to provide a growing portion of biofuel feedstocks. We sought to inform development of a 2G crop portfolio by assessing the profitability of novel cropping systems that potentially mitigate the negative effects of grain-based biofuel crops on food supply and environmental quality. We analyzed farm-gate costs and returns of five systems from an ongoing experiment in central Iowa, USA. The continuous corn cropping system was most profitable under current market conditions, followed by a corn–soybean rotation that incorporated triticale as a 2G cover crop every third year, and a corn–switchgrass system. A novel triticale–hybrid aspen intercropping system had the highest yields over the long term, but could only surpass the profitability of the continuous corn system when biomass prices exceeded foreseeable market values. A triticale/sorghum double cropping system was deemed unviable. We perceive three ways 2G crops could become more cost competitive with grain crops: by (1) boosting yields through substantially greater investment in research and development, (2) increasing demand through substantially greater and sustained investment in new markets, and (3) developing new schemes to compensate farmers for environmental benefits associated with 2G crops. (letter)

152

Farm-scale costs and returns for second generation bioenergy cropping systems in the US Corn Belt  

Science.gov (United States)

While grain crops are meeting much of the initial need for biofuels in the US, cellulosic or second generation (2G) materials are mandated to provide a growing portion of biofuel feedstocks. We sought to inform development of a 2G crop portfolio by assessing the profitability of novel cropping systems that potentially mitigate the negative effects of grain-based biofuel crops on food supply and environmental quality. We analyzed farm-gate costs and returns of five systems from an ongoing experiment in central Iowa, USA. The continuous corn cropping system was most profitable under current market conditions, followed by a corn-soybean rotation that incorporated triticale as a 2G cover crop every third year, and a corn-switchgrass system. A novel triticale-hybrid aspen intercropping system had the highest yields over the long term, but could only surpass the profitability of the continuous corn system when biomass prices exceeded foreseeable market values. A triticale/sorghum double cropping system was deemed unviable. We perceive three ways 2G crops could become more cost competitive with grain crops: by (1) boosting yields through substantially greater investment in research and development, (2) increasing demand through substantially greater and sustained investment in new markets, and (3) developing new schemes to compensate farmers for environmental benefits associated with 2G crops.

Manatt, Robert K.; Hallam, Arne; Schulte, Lisa A.; Heaton, Emily A.; Gunther, Theo; Hall, Richard B.; Moore, Ken J.

2013-09-01

153

Divesting in crop diversity: trade-offs of modern cropping systems  

Science.gov (United States)

Since the advent of the Green Revolution in the 1960's, agriculture has experienced great advances in yield, seed genetics and management. This focus on increased yields and production came at the cost of many marginal, traditional crops because they could no longer compete with the bountiful harvests of massive mono-culture food systems. In the modern agricultural world, three staple crops are responsible for 46% of global agricultural production on 33% of global harvested area. Further, seventeen crops account for 73% of global crop production and use 58% of global harvested area. How has the distribution of individual crops today changed from before the Green Revolution began, and what are the broader implications of these changes for our food systems?

Engstrom, P.

2013-12-01

154

Long-term effects of cropping systems on N2O emission potential  

DEFF Research Database (Denmark)

The potential for N2O emissions outside the main growing season may be influenced by long-term effects of cropping system. This was investigated by collecting intact soil cores (100 cm3, 0–4 cm depth) under winter wheat in three organic cropping systems and a conventional reference within a long-term crop rotation experiment. Average annual inputs of C in crop residues and manure ranged from 1.7 to 3.3 Mg ha?1. A simulated freeze–thaw cycle resulted in a flush of CO2 during the first 48 h, which could be mainly from microbial sources. Other samples were adjusted to approximately ?10, ?30 or ?100 hPa and amended with excess 15NO3? prior to freezing and thawing. Denitrification was the main source of N2O during a 72-h incubation at 22 °C, as judged from N2O and total 15N evolution. Although the input of C in the conventionally managed cropping system was significantly less than in the organic cropping systems, it showed higher N2O evolution at all three matric potentials. Estimates of relative gas diffusivity (DP/D0) in soil from the four cropping systems indicated that C input affected soil aeration. Soil from the two cropping systems with highest C input showed N2O evolution at DP/D0 in excess of 0.02, which is normally considered a threshold for development of anaerobic sites in the soil, presumably because the oxygen demand was also high. The study shows that cropping system affects both soil gas diffusivity and C availability, and that both characteristics significantly influence the N2O emission potential.

Petersen, SØren O; Ambus, Per

2013-01-01

155

Nitrogen management in organic farming: comparison of crop rotation residual effects on yields, N leaching and soil conditions  

OpenAIRE

After 3 years of different crop rotations in an organic farming experiment on a sandy soil in northwest Germany, spring triticale was cultivated on all plots in the fourth year to investigate residual effects on yield, nitrogen (N) leaching and nutrient status in the soil. Previous crop rotations differed in the way N was supplied, either by farmyard manure (FYM, 100 and 200 kg N ha?1 year?1) or by arable legumes like grass-red clover and field beans, or as a control with no N. Other...

Kayser, Manfred; Mu?ller, Ju?rgen; Isselstein, Johannes

2009-01-01

156

Role of Nematodes, Nematicides, and Crop Rotation on the Productivity and Quality of Potato, Sweet Potato, Peanut, and Grain Sorghum  

OpenAIRE

The objective of this experiment was to determine the effects of fenamiphos 15G and short-cycle potato (PO)-sweet potato (SP) grown continuously and in rotation with peanut (PE)-grain sorghum (GS) on yield, crop quality, and mixed nematode population densities of Meloidogyne arenaria, M. hapla, M. incognita, and Mesocriconema ornatum. Greater root-gall indices and damage by M. hapla and M. incognita occurred on potato than other crops. Most crop yields were higher and root-gall indices lower ...

Johnson, A. W.; Dowler, C. C.; Glaze, N. C.; Handoo, Z. A.

1996-01-01

157

Rotating Convection in an Anisotropic System  

OpenAIRE

We study the stability of patterns arising in rotating convection in weakly anisotropic systems using a modified Swift-Hohenberg equation. The anisotropy, either an endogenous characteristic of the system or induced by external forcing, can stabilize periodic rolls in the K\\"uppers-Lortz chaotic regime. For the particular case of rotating convection with time-modulated rotation where recently, in experiment, chiral patterns have been observed in otherwise K\\"uppers-Lortz-uns...

Roxin, Alex; Riecke, Hermann

2001-01-01

158

Effect of resource conserving techniques on crop productivity in rice-wheat cropping system  

International Nuclear Information System (INIS)

Rice-wheat cropping system is the most important one in Pakistan. The system provides food and livelihood for more than 15 million people in the country. The productivity of the system is much lower than the potential yields of both rice and wheat crops. With the traditional methods, rice-wheat system is not a profitable one to many farmers. Hence, Cost of cultivation must be reduced and at the same time, efficiency of resources like irrigation water, fuel, and fertilizers must be improved to make the crop production system more viable and eco- friendly. Resource conserving technology (RCT) must figure highly in this equation, since they play a major role in achieving the above goals. The RCT include laser land leveling, zero-tillage, bed furrow irrigation method and crop residue management. These technologies were evaluated in irrigated areas of Punjab where rice follows wheat. The results showed that paddy yield was not affected by the new methods. Direct seeding of rice crop saved irrigation water by 13% over the conventionally planted crop. Weeds were the major problem indirect seeded crop, which could be eliminated through cultural, mechanical and chemical means. Wheat crop on beds produced the highest yield but cost of production was minimum in the zero-till wheat crop. Planting of wheat on raised beds in making headway in low- lying and poorly drained areas. Thus, resource conserving tillage technology provides a tool for making progress towards improving and sor making progress towards improving and sustaining wheat production system, helping with food security and poverty alleviation in Pakistan in the next few decades. (author)

159

Nitrogen Leaching in Intensive Cropping Systems in Tam Duong District, Red River Delta of Vietnam  

OpenAIRE

The environmental and economic consequences of nitrogen (N) lost in rice-based systems in Vietnam is important but has not been extensively studied. The objective of this study was to quantify the amount of N lost in major cropping systems in the Red River Delta. An experiment was conducted in the Red River Delta of Vietnam, on five different crops including rose, daisy, cabbage, chili, and a rice–rice–maize rotation during 2004 and 2005. Core soil samples were taken periodically in 20-cm...

Trinh, M. V.; Keulen, H.; Roetter, R. P.

2010-01-01

160

Estimation of greenhouse gas emissions associated with cropping systems in southern Chile  

International Nuclear Information System (INIS)

The use of intensive traditional cropping systems with burning crop residues and soil plough down with heavy machinery in food production is considered the cause of environmental degradation, i.e. soil erosion and atmospheric contamination with carbon and nitrogen gaseous emissions. At a world scale the soil holds 1500 Gt of carbon, which can decrease by the inadequate soil management, increasing at the same time CO2 emission. Thus, traditional soil management can produce a large soil carbon reduction, whereas conservative soil management can increase soil carbon at a rate of 1 ton ha-1 per year. Research done by the IPCC, stated that in the next 50 to 100 years, soil might be a sink for 40-80 Gt of atmospheric carbon, if soil plough is substituted by no till with crop residues management over the soil surface, the use of appropriate crop rotations with the inclusion of grain legumes and the use of animal manure. In southern Chile, 70% of cropped land area is found, along with high level of soil degradation, since the dominant use of the traditional soil management. An exercise done with data collected from a Nitrogen Use Efficiency Research Project, on an Ultisol soil, the most eroded in southern Chile, demonstrate the feasibility of increase soil carbon sequestration shifting from soil ploughing to no burn-no till system and by the inclusion of legume crop in rotations. Soil carbon input can increase from 24 to 30.5 Gg under no burn no till, from crop res.5 Gg under no burn no till, from crop residues decomposition. These figures matches with real soil carbon variation content in the 0-20 cm depth, +2,2 10-6 Mg C ha-1 in no burn-no till systems in a 3 year period, and -3 10-1 Mg C ha-1 under traditional soil management. In the other hand with the continuous inclusion of grain legume crops in 188.000 has in rotation with grain annual crops, there is a potential to decrease carbon emission in 50 G, moreover, the shifting in the IX Region from traditional to conservation soil management system would mitigates carbon atmospheric emissions from 350 to 450 Gg

161

Efect of organic barley-based crop rotations on soil nutrient balance in a semiarid environment for a 16-year experiment  

Science.gov (United States)

In natural ecosystems with no percolating moisture regime, the biogeochemical cycle can be considered a closed system because the nutrients extracted by the roots will be returned to the soil after a certain time. In organic farming, a cycle model as close as possible is taken as a guideline, but we have to consider that unlike natural ecosystems, where most of the nutrients remain in the cycle, the agrosystems are open cycles. To achieve a sustainable fertility of the soil, the soil nutrient levels, the extractions according to the expected crop yields and the export refunds in the form of crop residues, biological nitrogen fixation, green manure or compost will have to be determined. Nutrient balance should be closed with external inputs, always avoiding to be a source of negative impacts on the environment. In organic farming without exogenous inputs, the effect of the crop rotations is much more noticeable in the nutrient balance than in the conventional farming fields which every year receive inputs of nutrients (nitrogen, phosphorus and potassium) in the form of chemical fertilizers. The most extractive crop rotations are those that produce a greater decrease in soil reserves, and in these cases exogenous inputs to maintain sustainability should be considered; however, in less extractive crop rotations, extractions can be restored by the edaphogenesis processes. In this work, soil organic matter, phosphorus and potassium balances were analyzed in different organic barley-based crop rotations (barley monoculture [b-b] and in rotation with vetch for hay production [B-Vh], vetch as green manure [B-Vm], sunflower [B-S], chickpea [B-C] and fallow [B-F]) in clay soils under a semiarid environment ("La Higueruela" Experimental Farm, Santa Olalla, Toledo, central Spain) over a 16 year period. Additionally, barley monoculture in conventional farming [B-B] was included. In the organic system, the fertilization involved the barley straw in all rotations, the sunflower straw in B-S, the symbiotic nitrogen from the vetch crops and the green manure in B-Vm. In the conventional system, fertilization consisted on barley straw and chemical fertilizers at a rate of 80-60-30 kg N-P-K ha-1. Before the organic management, the whole plot was subjected to conventional practices. The highest total yields (and therefore the nutrients extractions) were obtained in B-Vh, followed in this order by B-B, B-S, B-F, B-Vm, B-C and b-b. The crop rotations with the highest yields favoured the microbial activity and the organic residues mineralization, although this caused, eventually, a small decrease in the soil organic matter content. Since the eighth year, this parameter remained more stable until the end of the study period. The highest decrease of soil organic matter took place in B-F and B-S, while the lowest ones happened in B-B, where the great amounts of barley straw incorporated into the soil compensated the organic matter losses. The conversion from conventional to organic management with the incorporation of the straw to the soil implies a re-adaptation process with a decrease of the soil phosphorus level by the increasing soil microbial biomass. A decrease of phosphorus during the first six years of the experiment and a posterior recovery and stabilization of this ratio by the solubilisation of the fixed phosphorus was observed. B-F and B-S presented the lowest soluble phosphorus losses, while B-C the highest ones. In the same way, the potassium level decreased during the first eight years and after that remained constant. The highest decreases took place in the rotations with the biggest amounts of barley straw; this decrease could be explained by the nutrient immobilization caused by the microbial biomass.

Meco, Ramón; María Moreno, Marta; Lacasta, Carlos; Moreno, Carmen

2013-04-01

162

Scientific Basis for Sustainable Management of Eucalyptus and Populus as Short-Rotation Woody Crops in the U.S.  

Directory of Open Access Journals (Sweden)

Full Text Available Short rotation woody crops (SRWC, fast growing tree species that are harvested on short, repeated intervals, can augment traditional fiber sources. These crops have economic and environmental benefits stemming from their capability of supplying fiber on a reduced land base in close proximity to users and when sensitive sites cannot be accessed. Eucalyptus and Populus appear to be genera with the greatest potential to provide supplemental fiber in the U.S. Optimal productivity can be achieved through practices that overcome site limitations and by choosing the most appropriate sites, species, and clones. Some Eucalyptus species are potentially invasive, yet field studies across multiple continents suggest they are slower to disperse than predicted by risk assessments. Some studies have found lower plant and animal diversity in SRWC systems compared to mature, native forests, but greater than some alterative land uses and strongly influenced by stand management, land use history, and landscape context. Eucalyptus established in place of grasslands, arable lands, and, in some cases, native forests can reduce streamflow and lower water tables due to higher interception and transpiration rates but results vary widely, are scale dependent, and are most evident in drier regions.

Eric D. Vance

2014-05-01

163

Alternative Crop Rotations in the Semi-arid Central Great Plains Region: How Much Fallow? Evaluating the Economics  

Science.gov (United States)

The traditional crop production system in the semi-arid Central Great Plains Region (CGPR) of the U.S.A. is winter wheat (Triticum aestivum L.)-summer fallow (WF) or one crop every two years. This system is not a long-term sustainable dryland system. It is conducive to soil degradation and provide...

164

Chapter 3.1. Dynamics of legume nitrogen fixation in intercrops and in crop rotations  

International Nuclear Information System (INIS)

Use of nitrogen-15 lends understanding of the dynamics and interactions between various pools in agricultural systems, including nitrogen fixation by legumes and utilization of soil and fertilizer nitrogen by crops in general. Biological nitrogen fixation in sole and intercropped legumes is discussed, as are intercrop design and methods of assessing possible yield benefits from intercropping. Advantages that accrue from inclusion of legumes, only some of which are linked with nitrogen transfer, are discussed with particular reference to two case studies

165

On weed competition and population dynamics. Considerations for crop rotations and organic farming  

OpenAIRE

Key words: organic farming, weeds, weed management, weed ecology, weed diversity, matrix population model, elasticity analysis, neighbourhood model, survey, crop row spacing, mechanical hoe, harrow, Polygonum convolvulus , Polygonum persicaria , Stellaria mediaExperiments, monitoring studies and modelling of weed population dynamics were carried out to investigate potential methods for reducing weed populations in farming systems where herbicides are not applied (organic farming). Six years o...

Mertens, S. K.

2002-01-01

166

Emissions of nitrous oxide from arable organic and conventional cropping systems on two soil types  

DEFF Research Database (Denmark)

Conventional cropping systems rely on targeted short-term fertility management, whereas organic systems depend, in part, on long-term increase in soil fertility as determined by crop rotation and management. Such differences influence soil nitrogen (N) cycling and availability through the year. The main objective of this study was to compare nitrous oxide (N2O) emissions from soil under winter wheat (Triticum aestivum L.) within three organic and one conventional cropping system that differed in type of fertilizer, presence of catch crops and proportion of N2-fixing crops. The study was replicated in two identical long-term crop rotation experiments on sandy loam soils under different climatic conditions in Denmark (Flakkebjerg—eastern Denmark and Foulum—western Denmark). The conventional rotation received 165–170 kg N ha?1 in the form of NH4NO3, while the organic rotations received 100–110 kg N ha?1 as pig slurry. For at least 11 months, as from September 2007, static chambers were used to measure N2O emissions at least twice every calendar month. Mean daily N2O emissions across the year ranged from 172 to 438 ?g N m?2 d?1 at Flakkebjerg, and from 173 to 250 ?g N m?2 d?1 at Foulum. A multiple linear regression analysis showed inter-seasonal variations in emissions (P < 0.001), but annual N2O emissions from organic and conventional systems were not significantly different despite the lower N input in organic rotations. The annual emissions ranged from 54 to 137 mg N m?2, which corresponded to 0.5–0.8% of the N applied in manure or mineral fertilizer. Selected soil attributes were monitored to support the interpretation of N2O emission patterns. A second multiple linear regression analysis with potential drivers of N2O emissions showed a negative response to soil temperature (P = 0.008) and percent water-filled pore space (WFPS) (P = 0.052) at Foulum. However, there were positive interactions of both factors with NO3-N, i.e., high N2O emissions occurred during periods when high soil nitrate levels coincided with high soil temperature (P = 0.016) or high soil water content (P = 0.056). A positive effect (P = 0.03) of soil temperature was identified at Flakkebjerg, but the number of soil samplings was limited. Effects of cropping system on N2O emissions were not observed.

Chirinda, Ngoni; Carter, Mette Sustmann

2010-01-01

167

Emissions of nitrous oxide from arable organic and conventional cropping systems on two soil types  

DEFF Research Database (Denmark)

Conventional cropping systems rely on targeted short-term fertility management, whereas organic systems depend, in part, on long-term increase in soil fertility as determined by crop rotation and management. Such differences influence soil nitrogen (N) cycling and availability through the year. The main objective of this study was to compare nitrous oxide (N2O) emissions from soil under winter wheat (Triticum aestivum L.) within three organic and one conventional cropping system that differed in type of fertilizer, presence of catch crops and proportion of N2-fixing crops. The study was replicated in two identical long-term crop rotation experiments on sandy loam soils under different climatic conditions in Denmark (Flakkebjerg-eastern Denmark and Foulum-western Denmark). The conventional rotation received 165-170 kg N ha-1 in the form of NH4NO3, while the organic rotations received 100-110 kg N ha-1 as pig slurry. For at least 11 months, as from September 2007, static chambers were used to measure N2O emissions at least twice every calendar month. Mean daily N2O emissions across the year ranged from 172 to 438 µg N m-2 d-1 at Flakkebjerg, and from 173 to 250 µg N m-2 d-1 at Foulum. A multiple linear regression analysis showed inter-seasonal variations in emissions (P < 0.001), but annual N2O emissions from organic and conventional systems were not significantly different despite the lower N input in organic rotations. The annual emissions ranged from 54 to 137 mg N m-2, which corresponded to 0.5-0.8% of the N applied in manure or mineral fertilizer. Selected soil attributes were monitored to support the interpretation of N2O emission patterns. A second multiple linear regression analysis with potential drivers of N2O emissions showed a negative response to soil temperature (P = 0.008) and percent water-filled pore space (WFPS) (P = 0.052) at Foulum. However, there were positive interactions of both factors with NO3-N, i.e., high N2O emissions occurred during periods when high soil nitrate levels coincided with high soil temperature (P = 0.016) or high soil water content (P = 0.056). A positive effect (P = 0.03) of soil temperature was identified at Flakkebjerg, but the number of soil samplings was limited. Effects of cropping system on N2O emissions were not observed.

Chirinda, Ngonidzashe; Carter, Mette Sustmann

2010-01-01

168

Net global warming potential and greenhouse gas intensity influenced by irrigation, tillage, crop rotation, and nitrogen fertilization  

Science.gov (United States)

Little information exists about sources and sinks of greenhouse gases (GHGs) affected by management practices to account for net emissions from agroecosystems. We evaluated the effects of irrigation, tillage, crop rotation, and N fertilization on net global warming potential (GWP) and greenhouse gas...

169

Soil organic carbon across a Coastal Plain landscape: Effects of tillage and crop management systems  

Science.gov (United States)

Effective employment of conservation tillage (CT) and crop management practices to obtain significant amounts of C sequestration will require an understanding of quantitative relationships between crop residue inputs under different rotations and potential changes in soil organic carbon (SOC) conten...

170

Least limiting water range in soil under crop rotations and chiseling Intervalo hídrico ótimo em solo sob rotação de culturas e escarificação  

OpenAIRE

Soil water availability to plants is affected by soil compaction and other variables. The Least Limiting Water Range (LLWR) comprises soil physical variables affecting root growth and soil water availability, and can be managed by either mechanical or biological methods. There is evidence that effects of crop rotations could last longer than chiseling, so the objective of this study was to assess the effect of soil chiseling or growing cover crops under no-till (NT) on the LLWR. Crop rotation...

Juliano Carlos Calonego; Ciro Antonio Rosolem

2011-01-01

171

Assessment of Carbon Sequestration in German Alley Cropping Systems  

Science.gov (United States)

Alley cropping systems (ACS) are agroforestry practices in which perennial trees or shrubs are grown in wide rows and arable crops are cultivated in the alleys between the tree rows. Recently, ACS which integrate stripes of short rotation coppices into conventional agricultural sites have gained interest in Germany. These systems can be used for simultaneous production of crops and woody biomass which enables farmers to diversify the provision of market goods. Adding trees into the agricultural landscape creates additional benefits for the farmer and society also known as ecosystem services. An ecosystem service provided by land use systems is carbon sequestration. The literature indicates that ACS are able to store more carbon compared to agriculture and their implementation may lead to greater benefits for the environment and society. Moreover, carbon sequestration in ACS could be included in carbon trading schemes and farmers rewarded additionally for the provision of this ecosystem service. However, methods are required which are easy to use and provide reliable information regarding change in carbon sequestration with change of the land use practice. In this context, our aim was to develop a methodology to assess carbon sequestration benefit provided by ACS in Germany. Therefore, the change of carbon in both soil and biomass had to be considered. To predict the change in soil carbon our methodology combined the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and the soil organic carbon balance recommended by the Association of German Agricultural Investigation and Research Centers (VDLUFA). To reflect the change in biomass carbon average annual yields were adopted. The results showed that ACS established on agricultural sites can increase the carbon stored because in the new soil-plant system carbon content is higher compared to agriculture. ACS have been recommended as suitable land use systems for marginal sites, such as post-mining areas. In such areas soil carbon usually increases at a faster initial rate compared to agricultural land which means that these areas could provide high level of carbon sequestration service in the short term. The approach will be broadened to include assessment of other ecosystem services provided by ACS in Germany which would increase the possibility to adequately compensate farmers for the supply of environmental benefits. Keywords: agroforestry, biomass production, carbon sequestration, ecosystem services, marginal sites

Tsonkova, P. B.; Quinkenstein, A.; Böhm, C.; Freese, D.

2012-04-01

172

Integrating crops and livestock in subtropical agricultural systems.  

Science.gov (United States)

As the demand for livestock products increases, and is expected to continue to increase over the next few decades, especially in developing countries, smallholder mixed systems are becoming more intensive. However, with limited land and water resources and concern about the environmental impact of agricultural practices and climate change, the challenge is to find ways of increasing productivity that do not compromise household food security, but rather increase incomes equitably and sustain or enhance the natural resource base. In developed countries there has been increased specialisation of crop and livestock production. In contrast, the majority of livestock in developing countries is kept in mixed crop/livestock systems. Crops (cereal grains and pulses) and crop residues provide the basis of the diet for animals, e.g. cereal straw fed to dairy cattle or sweet potato vines fed to pigs. Animal manure can provide significant nutrient inputs to crops. Water productivity is higher in mixed crop/livestock systems compared with growing crops alone. Mixed systems allow for a more flexible and profitable use of family labour where employment opportunities are limited. They also spread risks across several enterprises, a consideration in smallholder systems that may become even more important under certain climate change scenarios. Integrated crop/livestock systems can play a significant role in improving global food security but will require appropriate technological developments, institutional arrangements and supportive policy environments if they are to fulfil that potential in the coming decades. PMID:21769884

Wright, Iain A; Tarawali, Shirley; Blümmel, Michael; Gerard, Bruno; Teufel, Nils; Herrero, Mario

2012-03-30

173

Optimization of Korean crop storage insulation systems  

Energy Technology Data Exchange (ETDEWEB)

With the increasing concerns with the quality and the safety of foods, several standards and guidelines have been developed to improve the design, construction and operation of storage warehouses. Several cool storage buildings have been constructed in Korea during the last decade. However, there are no specific standards or guidelines for energy use reduction in refrigerated structures. The main objective of this study is to determine the impact of various insulation systems on the total cooling load of the cool storage structures with particular consideration given to the product thermal mass to find optimal insulation thicknesses for each envelope component for various climatic locations in Korea. An energy analysis model was developed using the DOE-2.1E program. To determine the optimal configuration for the storage building insulation system, life cycle cost analysis was conducted. The selection of optimal insulation configuration for each climatic location is based on various criteria including cost and energy minimization. The results presented in this paper provide easy to use design guidelines to select the optimal insulation thickness for crop storage facilities in Korea. (Author)

Jongho Yoon [Taejon National Univ. of Technology, Dept. of Architectural Engineering, Taejon (Korea); Euyjoon Lee [Korea Inst. of Energy Research, Passive Solar Research Team, Taejon (Korea); Krarti, Moncef [Colorado Univ., CEAE Dept., Boulder, CO (United States)

2003-05-01

174

Energy efficiency in long-term Mediterranean cropping systems with different management intensities  

International Nuclear Information System (INIS)

Optimising the implementation of energy used in agriculture is an important objective in the 'Climate Action and Renewable Energy Package' adopted by the European Union. Therefore, studying the management of different cropping systems represents a good method to optimise input requirements, yield and net energy supply. The aim of this study is to compare the energy use of a 12-year rainfed cropping system, located in Tuscany, Italy. The system is cultivated under two different management intensities: a conventional system (CS) and a low input system (LIS) for a six-year crop rotation that included sugar beet, durum wheat, sorghum, sunflower, and durum wheat. In the sixth year, the soil was set-aside. The results showed that crop yield and energy yield were not significantly affected by management intensities, whereas energy efficiency of the low input system increased significantly, by about 30%. Future research should include more crops and locations to obtain further information about the range of energy parameters and their long-term trends. Furthermore, could be interesting to evaluate the overall reduction of environmental impacts and production costs that could occur limiting the use of chemicals and adopting conservative soil tillage strategies.

175

Using dual-purpose crops in sheep-grazing systems.  

Science.gov (United States)

The utilisation of dual-purpose crops, especially wheat and canola grown for forage and grain production in sheep-grazing systems, is reviewed. When sown early and grazed in winter before stem elongation, later-maturing wheat and canola crops can be grazed with little impact on grain yield. Recent research has sought to develop crop- and grazing-management strategies for dual-purpose crops. Aspects examined have been grazing effects on crop growth, recovery and yield development along with an understanding of the grazing value of the crop fodder, its implications for animal nutrition and grazing management to maximise live-weight gain. By alleviating the winter 'feed gap', the increase in winter stocking rate afforded by grazing crops allows crop and livestock production to be increased simultaneously on the same farm. Integration of dual-purpose wheat with canola on mixed farms provides further systems advantages related to widened operational windows, weed and disease control and risk management. Dual-purpose crops are an innovation that has potential to assist in addressing the global food-security challenge. PMID:24323974

Dove, Hugh; Kirkegaard, John

2014-05-01

176

Life-cycle assessment of net greenhouse-gas flux for bioenergy cropping systems.  

Science.gov (United States)

Bioenergy cropping systems could help offset greenhouse gas emissions, but quantifying that offset is complex. Bioenergy crops offset carbon dioxide emissions by converting atmospheric CO2 to organic C in crop biomass and soil, but they also emit nitrous oxide and vary in their effects on soil oxidation of methane. Growing the crops requires energy (e.g., to operate farm machinery, produce inputs such as fertilizer) and so does converting the harvested product to usable fuels (feedstock conversion efficiency). The objective of this study was to quantify all these factors to determine the net effect of several bioenergy cropping systems on greenhouse-gas (GHG) emissions. We used the DAYCENT biogeochemistry model to assess soil GHG fluxes and biomass yields for corn, soybean, alfalfa, hybrid poplar, reed canarygrass, and switchgrass as bioenergy crops in Pennsylvania, USA. DAYCENT results were combined with estimates of fossil fuels used to provide farm inputs and operate agricultural machinery and fossil-fuel offsets from biomass yields to calculate net GHG fluxes for each cropping system considered. Displaced fossil fuel was the largest GHG sink, followed by soil carbon sequestration. N20 emissions were the largest GHG source. All cropping systems considered provided net GHG sinks, even when soil C was assumed to reach a new steady state and C sequestration in soil was not counted. Hybrid poplar and switchgrass provided the largest net GHG sinks, >200 g CO2e-C x m(-2) x yr(-1) for biomass conversion to ethanol, and >400 g CO2e-C x m(-2) x yr(-1) for biomass gasification for electricity generation. Compared with the life cycle of gasoline and diesel, ethanol and biodiesel from corn rotations reduced GHG emissions by approximately 40%, reed canarygrass by approximately 85%, and switchgrass and hybrid poplar by approximately 115%. PMID:17494388

Adler, Paul R; Del Grosso, Stephen J; Parton, William J

2007-04-01

177

Soil nitrous oxide and methane fluxes in integrated crop-livestock systems in subtropics  

International Nuclear Information System (INIS)

Integrated crop-livestock (ICL) system is an agricultural practice in which crop-pasture rotation is carried out in the same field over time. In Brasil, ICL associated with no-tillage farming is increasingly gaining importance as a soil use strategy that improves food production (grain, milk and beef) and economic returns to farmers. Integrated crop-livestock-forestry (ICLF) is a recent modification of ICL in Brazil, with the inclusion of trees cultivation aiming at additional wood production and offering thermal comfort to livestock (Porfírio-da-Silva & Moraes, 2010). However, despite the increasing importance of ICL, little information is available on how this system may affect soil-atmosphere exchange of nitrous oxide (N2O) and methane (CH4)

178

An estimation of annual nitrous oxide emissions and soil quality following the amendment of high temperature walnut shell biochar and compost to a small scale vegetable crop rotation.  

Science.gov (United States)

Agricultural soils are responsible for emitting large quantities of nitrous oxide (N2O). The controlled incomplete thermal decomposition of agricultural wastes to produce biochar, once amended to soils, have been hypothesized to increase crop yield, improve soil quality and reduce N2O emissions. To estimate crop yields, soil quality parameters and N2O emissions following the incorporation of a high temperature (900 °C) walnut shell (HTWS) biochar into soil, a one year field campaign with four treatments (control (CONT), biochar (B), compost (COM), and biochar+compost (B+C)) was conducted in a small scale vegetable rotation system in Northern California. Crop yields from five crops (lettuce, winter cover crop, lettuce, bell pepper and Swiss chard) were determined; there were no significant differences in yield between treatments. Biochar amended soils had significant increases in % total carbon (C) and the retention of potassium (K) and calcium (Ca). Annual cumulative N2O fluxes were not significantly different between the four treatments with emissions ranging from 0.91 to 1.12 kg N2O-N ha(-1) yr(-1). Distinct peaks of N2O occurred upon the application of N fertilizers and the greatest mean emissions, ranging from 67.04 to 151.41 g N2O-N ha(-1) day(-1), were observed following the incorporation of the winter cover crop. In conclusion, HTWS biochar application to soils had a pronounced effect on the retention of exchangeable cations such as K and Ca compared to un-amended soils and composted soils, which in turn could reduce leaching of these plant available cations and could thus improve soils with poor nutrient retention. However, HTWS biochar additions to soil had neither a positive or negative effect on crop yield nor cumulative annual emissions of N2O. PMID:23490323

Suddick, Emma C; Six, Johan

2013-11-01

179

Efeito na produtividade da rotação de culturas de verão e crotalária no inverno / The efect of crotalaria cropped in the winter and of crop rotation on the yield of summer crops  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Em ensaio de rotação de culturas, conduzido em Pindorama, SP, num solo podzólico vermelho amarelo, fase arenosa, durante os anos agrícolas de 1991/92, 1992/93 e 1993/94, avaliou-se o efeito da rotação entre milho, soja e arroz, com e sem crotalária júncea de inverno, na produção das culturas, no fin [...] al do terceiro ano da experimentação. Não houve diferença entre tratamentos na produção da soja. A rotação aumentou a produção de arroz e milho, comparativamente ao monocultivo dessas culturas. A boa produtividade alcançada das culturas no terceiro ano pode ser atribuída, além da rotação, à ocorrência regular de chuvas e ao uso de cultivares tolerantes à acidez Abstract in english The effect of crop rotation among corn, soybean and rice as summer crops, and of crotalaria as a winter crop, was evaluated by the crop yield at the end of the third year.The experiment was established at Pindorama, SP, Brazil, on an acid soil(Red -Yellow Podzolic, sandy phase). After three years , [...] there was no yield difference among treatments for soybeam production. Crop rotation was beneficial for rice and corn prodution when compared to monocultures. The good productivity in the third year could also be atributed to regular rainfall and acidity tolerant cultivars.

H.A.A., MASCARENHAS; S.S.S., NOGUEIRA; R.T., TANAKA; A.L.M., MARTINS; Q.A.C., CARMELLO.

180

Nematode infestation and N-effect of legumes on soil and crop yelds in legume-sorghum rotations  

OpenAIRE

The effects of cowpea (Vignaunguiculata) and-groundnut (Arachis hypogea) on succeeding sorghum yields, soil mineral N and nematode infestationwere studied during five cropping seasons (2000 to 2004) in a weakly acid Ultisol of the agronomy research station of Farakô-Ba lo-cated in the Guinean zone of Burkina Faso, West Africa. A factorial 5x5 design of five crop rotations with five fertilizer treatments in a split-plot arrangement with four replications was used.Sorghum yields were affected ...

Abdoulsalam Sawadogo; Michel Cescas; Karim Traoré; Bouma Thio; Vincent Bado; André Bationo

2011-01-01

181

Rotations with Coastal Bermudagrass and Fallow for Management of Meloidogyne incognita and Soilborne Fungi on Vegetable Crops  

OpenAIRE

The efficacy of fallow and coastal bermudagrass (Cynodon dactylon) as a rotation crop for control of root-knot nematode (Meloidogyne incognita race 1) and soilborne fungi in okra (Hibiscus esculentus cv. Emerald), squash (Cucurbita pepo cv. Dixie Hybrid), and sweet corn (Zea mays cv. Merit) was evaluated in a 3-year field trial. Numbers of M. incognita in the soil and root-gall indices were greater on okra and squash than sweet corn and declined over the years on vegetable crops following fal...

Johnson, A. W.; Burton, G. W.; Wilson, J. P.; Golden, A. M.

1995-01-01

182

Silviculture and biology of short-rotation woody crops in temperate regions: Then and now  

Energy Technology Data Exchange (ETDEWEB)

Although its roots are in antiquity, the current concept of short-rotation woody crops (SRWC) for fiber and energy evolved scientifically from pioneering tree breeding work begun in the early 20th century. A natural outgrowth of this work was the culture of fast-growing trees on rotations of 1-15 years. Close-spaced tree culture received further impetus with the introduction of the 'silage sycamore' concept in the southeastern US in the mid-1960s and the OPEC oil embargo in 1973, leading to statistically designed trials at numerous locations in North America, Europe, and Scandinavia. Early silvicultural research focused on spacing and species trials, propagation methods, site preparation, weed management, nutrition, growth, and yield. Because these trials were based on small plots, and the importance of pest depredations or site variation were not fully recognized, early biomass yield predictions tended to be overly optimistic. Soon physiologists and ecologists began to unravel the biological characteristics of SRWC plantations and their responses to environment. Knowledge of the influence and diversity of pests-insects, diseases, and animals-provided a necessary reality check. Many hardwood tree species and a few conifers have been evaluated over the years for SRWC in temperate regions of the world. Clones of Populus and Salix, however, became the dominant plantation material because of their inherently rapid growth and ease of propagation by hardwood cuttings. Among conifers, loblolly pine (Pinus taeda) also shows promise. Because genetic variation is readily exploitable in the dominant SRWC taxa, strongly focused breeding programs began to provide highly productive genotypes and seed sources in the last decades of the 20th century. A new plateau, with significant practical potential, was reached in the late 20th century when biotechnological methods were applied to tree taxa. Recently, the DNA in the Populus genome was sequenced. Thus, the few current commercial applications of SRWC rest on a substantial base of silvicultural and biological knowledge. (author)

Dickmann, Donald I. [Department of Forestry, Michigan State University, East Lansing, MI 48824-1222 (United States)

2006-08-15

183

Establishment and Growth of Self-Seeded Winter Cereal Cover Crops in a Soybean-Corn Rotation  

Science.gov (United States)

Perpetuating cereal cover crops through self-seeding may increase adoption by reducing risk and cost. Winter rye (Secale cereale L.), wheat (Triticum aestivum L.), and triticale (x Triticosecale Wittmack) were used to develop self-seeding cover crop systems in a soybean [Glycine max (L.) Merr.]-corn...

184

EUE (energy use efficiency) of cropping systems for a sustainable agriculture  

International Nuclear Information System (INIS)

Energy efficiency of agriculture needs improvement to reduce the dependency on non-renewable energy sources. We estimated the energy flows of a wheat-maize-soybean-maize rotation of three different cropping systems: (i) low-input integrated farming (LI), (ii) integrated farming following European Regulations (IFS), and (iii) conventional farming (CONV). Balancing N fertilization with actual crop requirements and adopting minimum tillage proved the most efficient techniques to reduce energy inputs, contributing 64.7% and 11.2% respectively to the total reduction. Large differences among crops in energy efficiency (maize: 2.2 MJ kg-1 grain; wheat: 2.6 MJ kg-1 grain; soybean: 4.1 MJ kg-1 grain) suggest that crop rotation and crop management can be equally important in determining cropping system energy efficiency. Integrated farming techniques improved energy efficiency by reducing energy inputs without affecting energy outputs. Compared with CONV, energy use efficiency increased 31.4% and 32.7% in IFS and LI, respectively, while obtaining similar net energy values. Including SOM evolution in the energy analysis greatly enhanced the energy performance of IFS and, even more dramatically, LI compared to CONV. Improved energy efficiency suggests the adoption of alternative farming systems to reduce greenhouse gas emissions from agriculture. However, a thorough evaluation should include net global warming potential assessment. -- Highlights: ? We evaluated the energy flows of integrated as alternative to conventional Farming. ? Energy flows, soil organic matter evolution included, were analyzed following process analysis. ? Energy flows were compared using indicators. ? Integrated farming improved energy efficiency without affecting net energy. ? Inclusion of soil organic matter in energy analysis accrue environmental evaluation.

185

Feature Recognition System for Rotational Features  

Directory of Open Access Journals (Sweden)

Full Text Available This study presents the development of a knowledge-based features recognition system for mechanical parts. The main aim of the research was to concentrate on recognition of rotational features, namely, blind hole, through hole and slanting hole to be used in automatic process planning system. The rule-based technique was applied to recognize rotational features. The recognition criteria were based upon geometrical data from Standard for Exchange of Product data file (STEP of Computer-aided Design (CAD system. The system consists of several modules, namely, pre-processing module, inference engine module and user interface module. The developed system succeeds the design activities in manufacturing industries.

S.S.S. Ranjit

2013-01-01

186

Eucalyptus and Populus short rotation woody crops for phosphate mined lands in Florida USA  

Energy Technology Data Exchange (ETDEWEB)

Our short-rotation woody crops (SRWC) research in central and southern Florida is (1) developing superior Eucalyptus grandis (EG), E. amplifolia (EA), and cottonwood (Populus deltoides, PD) genotypes, (2) determining appropriate management practices for and associated productivities of these genotypes, and (3) assessing their economics and markets. Reclaimed clay settling areas (CSA) and overburden sites in phosphate mined areas in central Florida are a potential land base of over 80,000ha for SRWC production. On CSAs, PD grows well in the absence of cogongrass (Imperata cylindrica) but is not as productive as the non-invasive EG and EA. SRWC establishment on CSAs requires strict implementation of the following cultural practices: thorough site preparation through herbiciding/disking and bedding, superior trees, watering/packing seedlings, fertilization with ammonium nitrate at planting and annually thereafter as feasible, high planting density possibly including double row planting, and winter harvesting so that coppice regeneration suppresses weeds. PD cultural requirements, that may require post-planting weed control to suppress herbaceous competition, exceed those of the eucalypts. EG SRWCs on CSAs are at risk of blowdown 3-4 years after planting or coppicing; younger PD, EG, and EA SRWCs appear much less susceptible to wind damage. Genetic improvement must continue if EG, EA, and PD are to increase in commercial feasibility. SRWC cost competitiveness will depend on establishment success, yield improvements, harvesting costs, and identifying/using incentives. Strong collaboration among public and private partners is necessary for commercializing SRWCs in Florida. (author)

Rockwood, D.L.; Carter, D.R.; Langholtz, M.H. [The School of Forest Resources and Conservation, University of Florida, Box 110410, Gainesville, FL 32611 0410 (United States); Stricker, J.A. [Polk County Extension Service, University of Florida, Gainesville, FL 32611 (United States)

2006-08-15

187

Grassland carbon sequestration and emissions following cultivation in a mixed crop rotation  

DEFF Research Database (Denmark)

Grasslands are potential carbon sinks to reduce unprecedented increase in atmospheric CO2. Effect of age (1–4-year-old) and management (slurry, grazing multispecies mixture) of a grass phase mixed crop rotation on carbon sequestration and emissions upon cultivation was compared with 17-year-old grassland and a pea field as reference. Aboveground and root biomass were determined and soils were incubated to study CO2 emissions after soil disturbance. Aboveground biomass was highest in 1-year-old grassland with slurry application and lowest in 4-year-old grassland without slurry application. Root biomass was highest in 4-year-old grassland, but all 1–4-year-old grasslands were in between the pea field (0.81 ± 0.094 g kg?1 soil) and the 17-year-old grassland (3.17 ± 0.22 g kg?1 soil). Grazed grasslands had significantly higher root biomass than cut grasslands. There was no significant difference in the CO2 emissions within 1–4-year-old grasslands. Only the 17-year-old grassland showed markedly higher CO2 emissions (4.9 ± 1.1 g CO2 kg?1 soil). Differences in aboveground and root biomass did not affect CO2 emissions, and slurry application did not either. The substantial increase in root biomass with age but indifference in CO2 emissions across the age and management in temporary grasslands, thus, indicates potential for long-term sequestration of soil C.

Acharya, Bharat Sharma; Rasmussen, Jim

2012-01-01

188

Vibration Monitoring of Rotating Systems  

OpenAIRE

Most energy-conversion machines (e.g. vehicle engines and electric motors) involve rotating components (e.g. roller bearings and gears), which generate vibrations. The behavior of a pump which includes a deliberate fault was chosen to illustrate this assertion. The test bearing at the driven end of the pump’s motor was deliberately damaged using a 1.5mm wire-cutting method and an adjustable coupling disk introduced to impose a shaft misalignment of 40. The resulting undesirable behavior of ...

Probert, S. D.; Ogaji, S. O. T.; Lilly, M. T.; Ede, K. N.; Ogbonnaya, E. A.

2010-01-01

189

Meteorological risks and impacts on crop production systems in Belgium  

Science.gov (United States)

Extreme weather events such as droughts, heat stress, rain storms and floods can have devastating effects on cropping systems. The perspective of rising risk-exposure is exacerbated further by projected increases of extreme events with climate change. More limits to aid received for agricultural damage and an overall reduction of direct income support to farmers further impacts farmers' resilience. Based on insurance claims, potatoes and rapeseed are the most vulnerable crops, followed by cereals and sugar beets. Damages due to adverse meteorological events are strongly dependent on crop type, crop stage and soil type. Current knowledge gaps exist in the response of arable crops to the occurrence of extreme events. The degree of temporal overlap between extreme weather events and the sensitive periods of the farming calendar requires a modelling approach to capture the mixture of non-linear interactions between the crop and its environment. The regional crop model REGCROP (Gobin, 2010) enabled to examine the likely frequency and magnitude of drought, heat stress and waterlogging in relation to the cropping season and crop sensitive stages of six arable crops: winter wheat, winter barley, winter rapeseed, potato, sugar beet and maize. Since crop development is driven by thermal time, crops matured earlier during the warmer 1988-2008 period than during the 1947-1987 period. Drought and heat stress, in particular during the sensitive crop stages, occur at different times in the cropping season and significantly differ between two climatic periods, 1947-1987 and 1988-2008. Soil moisture deficit increases towards harvesting, such that earlier maturing winter crops may avoid drought stress that occurs in late spring and summer. This is reflected in a decrease both in magnitude and frequency of soil moisture deficit around the sensitive stages during the 1988-2008 period when atmospheric drought may be compensated for with soil moisture. The risk of drought spells during the sensitive stages of summer crops increases and may be further aggravated by atmospheric moisture deficits and heat stress. Summer crops may therefore benefit from earlier planting dates and beneficial moisture conditions during early canopy development, but will suffer from increased drought and heat stress during crop maturity. During the harvesting stages, the number of waterlogged days increases in particular for tuber crops. Physically based crop models assist in understanding the links between different factors causing crop damage. The approach allows for assessing the meteorological impacts on crop growth due to the sensitive stages occurring earlier during the growing season and due to extreme weather events. Though average yields have risen continuously between 1947 and 2008 mainly due to technological advances, there is no evidence that relative tolerance to adverse weather conditions such as atmospheric moisture deficit and temperature extremes has changed.

Gobin, Anne

2013-04-01

190

Sucessão de cultura sob pivô central para controle de fitonematoides: variação populacional, patogenicidade e estimativa de perdas Crop rotation in center-pivot for phytonematode control: density variation, pathogenicity and crop loss estimation  

Directory of Open Access Journals (Sweden)

Full Text Available Estudo de campo realizado em três anos consecutivos, em propriedade agrícola com sucessão de cultura, irrigada por pivô central e infestada pelos nematoides Pratylenchus brachyurus, P. zeae, Meloidogyne incognita, Paratrichodorus minor, Helicotylenchus dihystera, Mesocriconema ornata e M. onoense, comprovou que o controle dos nematoides polífagos é muito difícil. Dentre as culturas implantadas durante o período (algodão, milho, soja e caupi, o algodão se destacou pelas perdas causadas por M. incognita e a soja por P. brachyurus. A exclusão do milho, por ser suscetível a ambos os nematóides, porém tolerante a M. incognita, beneficiaria as culturas de algodão, soja e caupi. Resultados obtidos em condições controladas confirmaram a patogenicidade de P. brachyurus a algodoeiro. O uso da resistência genética como componente do manejo mostrou-se válido para o binômio soja/M. incognita, embora prejudicado pela baixa resistência da soja a P. brachyurus. Concluiu-se que a sucessão de cultura precisa ser cuidadosamente planejada em áreas infestadas com nematoides polífagos, principalmente naquelas em que ocorrem mais de duas espécies patogênicas às culturas utilizadas.A field study conducted over three consecutive years, on a farm using crop rotation system under center-pivot and infested with the nematodes Pratylenchus brachyurus, P. zeae, Meloidogyne incognita, Paratrichodorus minor, Helicotylenchus dihystera, Mesocriconema ornata and M. onoense, demonstrated that intensive crop systems provide conditions for the maintenance of high densities of polyphagous phytonematodes. Of the crops established on the farm (cotton, maize, soybean and cowpea, cotton and soybean suffered the most severe crop losses, caused respectively by M. incognita and P. brachyurus. Since maize is a good host for both nematodes, but tolerant of M. incognita, its exclusion from cropping system would be favorable to the performance of cotton, soybean and cowpea. Results from experiments carried out in controlled conditions confirmed the pathogenicity of P. brachyurus on cotton. Additional management with genetic resistance was useful in fields infested with M. incognita, although the soybean performance was affected by low resistance of the cultivars used for P. brachyurus. In conclusion, crop rotation must be carefully planned in areas infested with polyphagous nematodes, specifically in the case of occurrence of two or more major pathogenic nematodes.

Mário M. Inomoto

2011-06-01

191

A Rotative Electrical Impedance Tomography Reconstruction System  

International Nuclear Information System (INIS)

Electrical impedance tomography (EIT) is a powerful tool for mapping the conductivity distribution of estimated objects. The EIT system is entirely implemented by electrical technique, so it is a relatively cheap system and data can be collected very rapidly. But it has few commercially medical EIT systems available. This is because impedance image unable to achieve the essential spatial resolution and this technique has an intrinsically poor signal to noise ratio. In this paper, we have developed a high performance rotative EIT system (REIT) for expanding the independent measurements. By rotate the electrodes successive, REIT could change the position of electrodes and acquire more measurement data. This rotative measurement method not only can increase the resolution of impedance images, but also reduce the complexity of measurement system. We hope the improvement of REIT will bring some help in electrical impedance tomography

192

MODELIMG CROP PATTEN SYSTEM USING LINEAR PROGRAMMING  

Directory of Open Access Journals (Sweden)

Full Text Available In agricultural situations, farmers usually faced with the problem of how to allocate their limited production resources among cropping and livestock activities. Farmer's planners can offer effective techniques, such as linear programming (lp to address the problem and produce optimal solution. In this paper we have demonstrated that how a farmer who has limited resources such as farmers availability ,storage capacity and availability of land can be formulated as a linear programming having linear objective function with three constraints. The objective is to develop an understanding of utility of farmer's availability resources and then maximization of total profit. In our case we have selected two crops rice and corn, formulate the (lp problem and after solving through LINGO, the results showed that farmer obtained maximum profit using his resources.

Mushtaq A. Lone

2014-06-01

193

The potential for short-rotation woody crops to reduce US CO2 emissions  

International Nuclear Information System (INIS)

Short-rotation woody crops (SRWC) could potentially displace fossil fuels and thus mitigate CO2 buildup in the atmosphere. To determine how much fossil fuel SRWC might displace in the United States and what the associated fossil carbon savings might be, a series of assumptions must be made. These assumptions concern the net SRWC biomass yields per hectare (after losses); the amount of suitable land dedicated to SRWC production; wood conversion efficiencies to electricity or liquid fuels; the energy substitution properties of various fuels; and the amount of fossil fuel used in growing, harvesting, transporting, and converting SRWC biomass. Assuming the current climate, present production, and conversion technologies and considering a conservative estimate of the US land base available for SRWC (14 x 106 ha), it is calculated that SRWC energy could displace 33.2 to 73.1 x 106 Mg of fossil carbon releases, 3-6% of the current annual US emissions. The carbon mitigation potential per unit of land is larger with the substitution of SRWC for coal-based electricity production than for the substitution of SRWC-derived ethanol for gasoline. Assuming current climate, predicted conversion technology advancements, an optimistic estimate of the US land base available for SRWC (28 x 106 ha), and an optimistic average estimate of net SRWC yields (22.4 dry Mg/ha), it is calculate that SRWC energy could displace 148 to 242 x 106 Muld displace 148 to 242 x 106 Mg of annual fossil fuel carbon releases. Under this scenario, the carbon migration potential of SRWC-based electricity production would be equivalent to about 4.4% of current global fossil fuel emissions and 20% of current US fossil fuel emissions. 21 refs., 5 tabs

194

Rotation–Invariant Fingerprint Identification System  

Directory of Open Access Journals (Sweden)

Full Text Available The fingerprint is the most widely used Biometric. The main focus of Intelligent Fingerprint Recognition System is to improve accuracy and efficiency.This system uses an algorithm for recovering translation parameters from two fingerprint images of the same individual that differ by Scaling, Rotation, and Transformation also known as similarity transformation or Rotation-scale-Translation (RST Transformation. This algorithm is very useful to identify two fingerprint images of the same individual which are misaligned by small transformations such as rotation or translation or scaling.The algorithm uses minutiae based matching to compare input fingerprint image with the template fingerprint image stored in the database. The algorithm uses various standard preprocessing steps. It includes all the stages to extract the minutiae. Maximum correlation between original and sensed image is found. The proposed system is tested on the pilot database.

R. M.Mandi

2012-07-01

195

Infiltração de água no solo sob escarificação e rotação de culturas / Water infiltration in soil as influenced by chiseling and crop rotations  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Nos solos com restrições físicas e, ou, físico-hídricas ao crescimento de raízes, aumentar o potencial de armazenagem de água por meio de melhorias na infiltração pode ser uma estratégia viável para aumento da produtividade das culturas. Nesse sentido, este trabalho teve como objetivo avaliar a infi [...] ltração de água em um Nitossolo Vermelho distrófico, com três sistemas de rotação de culturas sob semeadura direta com e sem escarificação inicial. O sistema de rotação de culturas constou de: (1) milheto/soja/sorgo/milho/sorgo (M/S/So/Mi/So), (2) milheto/soja/Brachiaria ruziziensis/milho/Brachiaria ruziziensis (M/S/B/Mi/B) e (3) milheto/soja/Brachiaria ruziziensis + mamona/milho/Brachiaria ruziziensis + mamona (M/S/B+Ma/Mi/B+Ma). A infiltração de água no solo foi avaliada em campo com anéis concêntricos instalados na superfície, a 0,10 e 0,20 m de profundidade, em 2006 e 2007. Após o primeiro ano, o manejo com escarificação inicial do solo apresentou a maior infiltração de água. A rotação Brachiaria ruziziensis + mamona proporcionou maior infiltração da água no solo. A atividade do sistema radicular das espécies nas parcelas sem escarificação inicial aumentou a velocidade de infiltração da água no solo. Abstract in english In soils with physical and/or physical hydric restrictions for root growth, it may be a viable strategy to increase crop productivity by increasing water storage potential through improvements in water infiltration. Accordingly, the objective of this study was to determine water infiltration in a Ha [...] pludult in three crop rotations under no-tillage, with and without initial chiseling. Crop rotations consisted of: millet/soybean/sorghum/maize/sorghum; millet/soybean/Brachiaria ruziziensis/corn/Brachiaria ruziziensis; and millet/soybean/Brachiaria ruziziensis + castor bean/corn/Brachiaria ruziziensis + castor bean. Water infiltration in soil was evaluated in the field, using concentric discs at the soil surface and at depths of 0.10 and 0.20 m, in 2006 and 2007. After the first year, chiseling led to increased infiltration of water into the soil. Water infiltration was greatest in the crop rotation system with Brachiaria ruziziensis + castor bean. The activity of root systems of crops in the plots without chiseling increased the rate of water infiltration into the soil.

Maryara Buriola, Prando; Dácio, Olibone; Ana Paula Encide, Olibone; Ciro Antonio, Rosolem.

2010-06-01

196

Absence of genetic divergence between western corn rootworms (Coleoptera: Chrysomelidae) resistant and susceptible to control by crop rotation.  

Science.gov (United States)

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a major pest of corn, Zea mays L., in North America that has recently invaded Europe. A loss of ovipositional fidelity to cornfields has allowed the species to circumvent crop rotation as a means of control in part of its range in the United States. Analyses of variation at eight microsatellite loci provided no evidence for general genetic differentiation between samples of western corn rootworm collected in soybean, Glycine max (L.) Merr., fields and those collected in cornfields both inside and outside the rotation-resistance problem area. This result suggests that few or no barriers to gene flow exist between rotation-resistant and -susceptible rootworm populations. The implications of this result for the management of western corn rootworm in North America and Europe are discussed. PMID:16813299

Miller, N J; Kim, K S; Ratcliffe, S T; Estoup, A; Bourguet, D; Guillemaud, T

2006-06-01

197

Cowpea Crude Protein as Affected by Cropping System, Site and Nitrogen Fertilization  

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Full Text Available High protein content in cowpea (Vigna unguiculata (L. Walp. is considered as major advantage for its use in nutritional components. In this way, an experiment was conducted to investigate the effect of cropping system, site, and nitrogen fertilization on cowpea crude protein. The study comprised of three cropping systems (Maize-cowpea rotation, monocropping cowpea and intercropped cowpea, three sites (Potchefstroom, Taung, and Rustenburg, South Africa and two rates of nitrogen fertilizers applied in kg ha-1 at each site (0 and 20 at Potchefstroom, 0 and 17 at Rustenburg, 0 and 23 at Taung. Moreover, a factorial experiment randomized in complete block design with three replications was conducted during 2011/12 and 2012/13 planting seasons. The protein content was determined from green leaves harvested before flowering, immature green pods and seeds during reproductive stage and maturity. Results showed that cropping system had significant effect on cowpea leaf protein content (P < 0.05. Intercropped cowpea significantly gave higher leaf protein (26.7% more content than rotational cowpea. Cowpea planted at Taung had significantly higher leaf protein (30.1% more content as compared to cowpea planted at other sites. Application of nitrogen fertilizer contributed to higher protein content of immature pods. Moreover, cowpea protein content differs among the different locations due to different soil types and climatic conditions.

E. T. Sebetha

2014-12-01

198

Rotating Convection in an Anisotropic System  

CERN Document Server

We study the stability of patterns arising in rotating convection in weakly anisotropic systems using a modified Swift-Hohenberg equation. The anisotropy, either an endogenous characteristic of the system or induced by external forcing, can stabilize periodic rolls in the K\\"uppers-Lortz chaotic regime. For the particular case of rotating convection with time-modulated rotation where recently, in experiment, chiral patterns have been observed in otherwise K\\"uppers-Lortz-unstable regimes, we show how the underlying base-flow breaks the isotropy, thereby affecting the linear growth-rate of convection rolls in such a way as to stabilize spirals and targets. Throughout we compare analytical results to numerical simulations of the Swift-Hohenberg equation.

Roxin, A; Roxin, Alex; Riecke, Hermann

2002-01-01

199

Integrated soil-crop system management for food security.  

Science.gov (United States)

China and other rapidly developing economies face the dual challenge of substantially increasing yields of cereal grains while at the same time reducing the very substantial environmental impacts of intensive agriculture. We used a model-driven integrated soil-crop system management approach to develop a maize production system that achieved mean maize yields of 13.0 t ha(-1) on 66 on-farm experimental plots--nearly twice the yield of current farmers' practices--with no increase in N fertilizer use. Such integrated soil-crop system management systems represent a priority for agricultural research and implementation, especially in rapidly growing economies. PMID:21444818

Chen, Xin-Ping; Cui, Zhen-Ling; Vitousek, Peter M; Cassman, Kenneth G; Matson, Pamela A; Bai, Jin-Shun; Meng, Qing-Feng; Hou, Peng; Yue, Shan-Chao; Römheld, Volker; Zhang, Fu-Suo

2011-04-19

200

Integrated soil–crop system management for food security  

Science.gov (United States)

China and other rapidly developing economies face the dual challenge of substantially increasing yields of cereal grains while at the same time reducing the very substantial environmental impacts of intensive agriculture. We used a model-driven integrated soil–crop system management approach to develop a maize production system that achieved mean maize yields of 13.0 t ha?1 on 66 on-farm experimental plots—nearly twice the yield of current farmers’ practices—with no increase in N fertilizer use. Such integrated soil–crop system management systems represent a priority for agricultural research and implementation, especially in rapidly growing economies. PMID:21444818

Chen, Xin-Ping; Cui, Zhen-Ling; Vitousek, Peter M.; Cassman, Kenneth G.; Matson, Pamela A.; Bai, Jin-Shun; Meng, Qing-Feng; Hou, Peng; Yue, Shan-Chao; Römheld, Volker; Zhang, Fu-Suo

2011-01-01

201

Using the DNDC model to compare soil organic carbon dynamics under different crop rotation and fertilizer strategies  

Energy Technology Data Exchange (ETDEWEB)

Soil organic carbon (SOC) plays a vital role in determining soil fertility, water holding capacity and susceptibility to land degradation. On the Chinese Loess Plateau, a large amount of crop residues is regularly removed; therefore, this agricultural area mainly depends on fertilizer inputs to maintain crop yields. This paper aims to use a computer simulation model (DeNitrification and DeComposition, or DNDC) to estimate the changes of SOC content and crop yield from 1998 to 2047 under different cropping systems, providing some strategies to maintain the SOC in balance and to increase crop yields. The results demonstrated that: (i) single manure application or combined with nitrogen fertilizer could significantly enhance the SOC content and crop yield on the sloped land, terraced field and flat land; and (ii) in contrast to sloped land and terraced field, the SOC content and crop yield both continuously increased in flat fields, indicating that the flat field in this region is a good soil surface for carbon sequestration. These results emphasize that application of manure combined with nitrogen fertilizer would be a better management practice to achieve a goal of increasing soil carbon sequestration and food security. (Author)

Mu, L.; Liang, Y.; Xue, Q.; Chen, C.; Lin, X.

2014-06-01

202

Influence of Cropping System Intensity on Dry Matter Yield and Nitrogen Concentration in Different Parts of Soybean Plant  

OpenAIRE

Two-year investigations were conducted within the three-year maize-soybean-wheat crop rotation with the aim to assess the influence of two cropping systems, conditionally marked as high-input and reduced-input systems, on soybean dry matter yield and nitrogen concentration in its different plant parts. The high-input system was characterized by: ploughing at 30-32 cm, fertilization with 80 kg N and 130 P2O5 and K2O kg ha-1, weed control based on oxasulfuron and, if required, a corrective trea...

Klaudija Carovi?; Zlatko Sve?njak; Ana Pospišil; Boris Varga

2006-01-01

203

Effect of tillage, rotation and crop residues on wheat crop productivity, fertilizer nitrogen and water use efficiency and soil organic carbon status in dry area (rainfed) of north-west Pakistan  

Scientific Electronic Library Online (English)

Full Text Available Crop productivity, soil organic carbon (SOC), fertilizer nitrogen and water use efficiency (WUE) in rainfed dry area is influenced by tillage, rotation and crop residues management. Field experiments were conducted during 2004-09 to study the effect of tillage, rotation and crop residues on wheat yi [...] eld, nitrogen fertilizer and water use efficiency and SOC under semi-arid condition in north-west Pakistan. The treatments consisted of three rotations: i) Wheat-fallow-wheat (farmers' practice) ii) Wheat- summer legume-wheat and iii) Wheat-summer cereal-wheat with two tillage and crop residues management treatments: i) Tillage (crop residues removed) and Tillage (crop residues retained) and ii) No-tillage (crop residues removed) and No-tillage (crop residues retained). Basal doses of N60: P60 (kg ha-1) to wheat, N90: P60 and N20: P60 (kg ha-1) to summer cereals and legumes rotation crops were applied respectively. Labeled urea having 1% 15N atom excess at 60 kg N ha-1 was applied to wheat as an aqueous solution in micro plot within each treatment plot. Changes in soil water storage were monitored with neutron moisture probe for calculation of WUE. The results revealed that the wheat grain and straw yield was not increased by the tillage treatment. Crop residues retention significantly enhanced the wheat grain and straw yield. Crop residues with no-tillage resulted in 520 kg ha-1 greater wheat grain yield than residues removed treatment. Similarly WUE, N yield and fertilizer N utilization by wheat was increased significantly by crop residues under no-tillage compared to the tillage treatment. Maximum N fertilizer utilization 24.1 %, 62.7 % and 38.0 % in wheat were obtained under no-tillage + residues treatment during 2006, 2007 and 2008 respectively. The SOC in surface soil (0-15 cm) was higher in wheat-fallow-wheat and wheat-legume-wheat rotation under no-tillage + residues treatment. The results showed that no-tillage + crop residues and legume based rotation treatment were beneficial under the rainfed (dry) conditions.

W, Mohammad; S. M, Shah; S, Shehzadi; S. A, Shah.

2012-12-01

204

Economics of short-rotation woody crops plantation at Amana, Iowa  

International Nuclear Information System (INIS)

This paper reports on a 21 ha energy plantation of silver maple (Acer saccharinum) established on an old-field bottomland site near Amana, IA. The project started in 1988 and sponsored by the Oak Ridge National Laboratory, (US Dept. of Energy), is a 6 year cooperative effort of the Amana Society, Department of Forestry, ISU, and the Iowa Dept. of Natural Resources. The objective is to accurately estimate biomass yields and costs of growing wood for energy in a short-rotation, close spacing system under operational conditions. Research is being conducted on spacing rotation, fertilization, groundwater quality, and improved seedlings. A detailed cost accounting system was established to accurately record time and cost data by activity. Establishment costs (rent, site preparation, tree planting) and initial (2 year) cultural management costs (herbicide and mowing) total $1,304/ha. Cost proportions for rent, site preparation, and planting are 11%, 18.2%, and 59.4%, respectively. Cultural management costs incurred through 1990 total $148/ha

205

Productivity of winter rye in organic vs. Conventional cropping system  

Directory of Open Access Journals (Sweden)

Full Text Available Rye is a cereal which is very much demanded at the market, for making a special kind of bread, but it is little grown in Serbia. The aim of this paper is to investigate possibilities of organic growing of winter rye, comparing with the conventional one, in agroecological conditions of Valjevo hilly region during 2008/2009 and 2009/2010 cropping seasons. The trial was set up in a village of Kotešica, on soil which had not been used for agriculture for 7 years. In organic cropping system three combinations of microbiological fertiliser baktofil with zeolite and hydrogel were used prior to sowing. Half of each plot was treated with foliar microbiological fertiliser Slavol during crop growing period. In conventional cropping system three variants with mineral fertilisers were included: NPK, NPK+zeolite, NPK+hydrogel. Results of the yield obtained in the experiment showed a significant difference between two seasons, 2008/2009 and 2009/2010. In comparison with the control, the treatments in an organic cropping system resulted with statistically insignificant differences for mean values in both years, while the mean in conventional cropping system has significantly higher yield of winter rye. Organic cropping system under conditions of Valjevo hilly region did not give significantly lower rye yield compared with the conventional one in a moderate growing season such was 2008/2009. The combination of soil microbiological fertiliser (Baktofil with foliar fertiliser (Slavol and zeolite gave the highest winter rye grain yield in all other treatments in the second year of investigation. In a very wet season (2009/2010 mineral fertiliser NPK showed an advantage, especially in combinations with zeolite, and this treatment can be recommended.

Olja?a Jasmina M.

2010-01-01

206

Influence of crop rotation and meteorological conditons on density and biomass of weeds in spring barley (Hordeum vulgare L.  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents the analysis of changes in weed infestation in spring barley cultivated in the years 1990-2004 in crop rotation with a 25% proportion of this cereal (potato - spring barley - sowing peas - winter triticale, when it was grown after potato, and in crop rotation with its 75% proportion (potato - spring barley - spring barley - spring barley, when it was grown once or twice after spring barley. In the experiment, no weed control was applied. Every year in the spring (at full emergence of the cereal and before the harvest, the composition of weed species and weed density of particular weed species were determined, and before the harvest also their biomass. Weed density increased linearly on all plots during the 15-year period. The average values confirm the increase in weed biomass in the case when spring barley was grown once or twice after this crop; however, those differences were influenced by the previous situation only during some seasons. Weed density and biomass showed high year-to-year variability and a positive correlation with the amount of precipitation and a negative correlation with temperature during the period of the study. A negative correlation between the yield of barley and weed biomass was shown.

Maria Wanic

2010-06-01

207

Evaluation of Carabid Beetle Diversity in Different Bioenergy Cropping Systems  

Directory of Open Access Journals (Sweden)

Full Text Available Normal 0 7.8 ? 0 2 false false false EN-US ZH-CN X-NONE MicrosoftInternetExplorer4 Changes in agricultural land use as a consequence of an increased demand of energy crops have resulted in an increase of maize cropped area in many regions of Germany. The focus on maize as main biogas substrate, has led in some cases to negative ecological and environmental impacts, such as a loss of agro biodiversity reflected in a loss of field flora and fauna biodiversity. The present paper deals with the evaluation of the fauna in different bioenergy cropping systems on two sites in South-West Germany, with a special focus on the species richness of carabid beetle (Coleoptera: Carabidae assemblages as an indicator for the general status of diversity. A maize field, an agroforestry system with maize and different tree species as well as different alternative biogas crops (amaranth, sunflower was investigated for their carabid beetle activity, density, and species richness using pitfall traps. Moreover, for an adequate evaluation of the carabid assemblages different common diversity indices (Shannon-Wiener diversity (H’, Simpson diversity (D and Evenness (J’ were used. In the case of the maize field on both field edges 8 and 6 carabid beetle species, respectively were trapped, while in the field centre 2 carabid beetle species were trapped. The agroforestry system indicated slightly higher crabid beetle species richness close to the tree strips. The investigation of alternative biogas crops showed no significant differences in carabid beetle diversity. Overall, the results of the different studies showed, that biodiversity of bioenergy cropping systems could be enhanced by the creation of refuge areas for carabid beetles or other animals. Refuges could be either field margins with grass and hedgerows or strips of more extensively used perennial energy crops across the field.

Benjamin Mast

2012-06-01

208

Long-term effects of cropping system on N2O emission potential  

DEFF Research Database (Denmark)

The potential for N2O emissions outside the main growing season may be influenced by long-term effects of cropping system. This was investigated by collecting intact soil cores (100 cm3, 0-4 cm depth) under winter wheat in three organic cropping systems and a conventional reference within a long-term crop rotation experiment. Average annual inputs of C in crop residues and manure ranged from 1.7 to 3.3 Mg ha-1. A simulated freeze-thaw cycle resulted in a flush of CO2 during the first 48 h, which could be mainly from microbial sources. Other samples were adjusted to approximately –10, -30 or –100 hPa and amended with excess 15NO3- prior to freezing and thawing. Denitrification was the main source of N2O during a 72-h incubation at 22 °C, as judged from N2O and total 15N evolution. Although the input of C in the conventionally managed cropping system was significantly less than in the organic cropping systems, it showed higher N2O evolution at all three matric potentials. Estimates of relative gas diffusivity (DP/D0) in soil from the four cropping systems indicated that C input affected soil aeration. Soil from the two cropping systems with highest C input showed N2O evolution at DP/D0 in excess of 0.02, which is normally considered a threshold for development of anaerobic sites in the soil, presumably because the oxygen demand was also high. The study shows that cropping system affects both soil gas diffusivity and C availability, and that both characteristics significantly influence the N2O emission potential.

Petersen, SØren O.; Ambus, Per

2013-01-01

209

Potential of short rotation wood crops as a fiber and energy source in the U.S.  

Energy Technology Data Exchange (ETDEWEB)

The use of short rotation wood crops (SRWC) as dedicated energy sources is constrained by their high price. An alternative approach is to produce co-products from SRWC, including higher-value fibers (i.e., paper and pulp, veneers, engineered wood products, etc.) and lower-value energy. The U.S. Departments of Energy and Agriculture are working together to explore the economic potential of this approach. An agricultural sector model (POLYSYS) has been modified to include switchgrass, hybrid poplar, and willow, and it is currently being used to evaluate the price, quantity, and location of energy crop production and the potential effects (prices, quantities, and net returns) of large scale energy crop production on traditional crops. This modeling is being extended to evaluate the economic competitiveness of using SRWC for fiber and energy by linking the modified POLYSYS model with U.S. Forest Service models (NAPAP - paper and pulp; TAMM/ATLAS - lumber supply and wood panels market). The linked models will estimate the potential SRWC fiber demand, SRWC supply, equilibrium SRWC fiber quantities and prices, and selected effects on traditional forest management activities. Additionally, SRWC residue quantities potentially available for energy use will be estimated. (author)

Walsh, M.E. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Ince, P.J. [USDA, Madison (United States). Forest Service; Adams, D. [Oregon State University, Corvallis (US)] [and others

1999-07-01

210

Agregados em um Latossolo sob sistema plantio direto e rotação de culturas / Aggregates in a Rhodic Ferralsol under no-tillage and crop rotation  

Scientific Electronic Library Online (English)

Full Text Available O objetivo deste trabalho foi avaliar a influência dos cultivos de outono-inverno e primavera, em sistema de plantio direto, nos agregados e matéria orgânica de um Latossolo. O experimento foi conduzido durante as safras 2006/2007, 2007/2008 e 2008/2009. No outono-inverno foram estabelecidas parcela [...] s principais com braquiária (Urochloa ruziziensis), sorgo granífero (Sorghum bicolor) e sorgo consorciado com braquiária. Na primavera, foram cultivados, em subparcelas, milheto (Pennisetum glaucum), 'Cober Crop' (Sorghum bicolor x Sorghum sudanense), crotalária (Crotalaria juncea) ou pousio. A soja foi cultivada como safra de verão, o que totalizou 12 tratamentos. A massa de matéria seca e o crescimento radicular das plantas de cobertura da primavera foram determinados em 2006 e 2008. Foram coletadas amostras de solo nas camadas de 0-5 e 5-10 cm, após o manejo das plantas de cobertura de primavera, no primeiro e terceiro anos agrícolas. Foram determinados o diâmetro médio ponderado, o diâmetro médio geométrico, o índice de estabilidade de agregados, os agregados maiores que 2 mm, a matéria orgânica e os teores de carbono orgânico total nas amostras coletadas no terceiro ano. O milheto e 'Cober Crop' produziram maior quantidade de massa de matéria seca e maior crescimento radicular. A estruturação do solo melhorou com a rotação dos cultivos das plantas de cobertura antecedentes à safra de verão. O cultivo de 'Cober Crop' e milheto influenciou a formação de macroagregados nas camadas superficiais Abstract in english The objective of this work was to evaluate the influence of fall-winter and spring crops, cultivated under no-tillage system, on the aggregates and organic matter of a Rhodic Ferralsol. The experiment was performed in the 2006/2007, 2007/2008 and 2008/2009 growing seasons. Congo signal grass (Urochl [...] oa ruziziensis), grain sorghum (Sorghum bicolor) and sorghum mixed with brachiaria were cropped in the fall-winter to consist the main plots. In the spring, millet (Pennisetum glaucum), 'Cober Crop' (Sorghum bicolor x Sorghum sudanense) and Indian hemp (Crotalaria juncea) were cultivated as subplots as well as a fallow treatment. Soybean was cropped in the summer, totaling 12 treatments. Cover crop dry matter and root growth were evaluated in 2006 and 2008. Soil samples were taken from 0-5 and 5-10 cm depths, after spring cover crops managing, in the first and third years. The mean weight diameter, geometric mean diameter, aggregate stability index, aggregates larger than 2 mm, organic matter and total organic carbon levels were evaluated in the samples of the third year. Millet and 'Cober Crop' showed higher dry matter production and root growth. The soil aggregation was improved by cover crop rotations before the summer growing season. The cultivation of 'Cober Crop' and millet influenced the macroaggregate formation in the superficial layers

Rodrigo Arroyo, Garcia; Ciro Antonio, Rosolem.

1489-14-01

211

Agregados em um Latossolo sob sistema plantio direto e rotação de culturas Aggregates in a Rhodic Ferralsol under no-tillage and crop rotation  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi avaliar a influência dos cultivos de outono-inverno e primavera, em sistema de plantio direto, nos agregados e matéria orgânica de um Latossolo. O experimento foi conduzido durante as safras 2006/2007, 2007/2008 e 2008/2009. No outono-inverno foram estabelecidas parcelas principais com braquiária (Urochloa ruziziensis, sorgo granífero (Sorghum bicolor e sorgo consorciado com braquiária. Na primavera, foram cultivados, em subparcelas, milheto (Pennisetum glaucum, 'Cober Crop' (Sorghum bicolor x Sorghum sudanense, crotalária (Crotalaria juncea ou pousio. A soja foi cultivada como safra de verão, o que totalizou 12 tratamentos. A massa de matéria seca e o crescimento radicular das plantas de cobertura da primavera foram determinados em 2006 e 2008. Foram coletadas amostras de solo nas camadas de 0-5 e 5-10 cm, após o manejo das plantas de cobertura de primavera, no primeiro e terceiro anos agrícolas. Foram determinados o diâmetro médio ponderado, o diâmetro médio geométrico, o índice de estabilidade de agregados, os agregados maiores que 2 mm, a matéria orgânica e os teores de carbono orgânico total nas amostras coletadas no terceiro ano. O milheto e 'Cober Crop' produziram maior quantidade de massa de matéria seca e maior crescimento radicular. A estruturação do solo melhorou com a rotação dos cultivos das plantas de cobertura antecedentes à safra de verão. O cultivo de 'Cober Crop' e milheto influenciou a formação de macroagregados nas camadas superficiaisThe objective of this work was to evaluate the influence of fall-winter and spring crops, cultivated under no-tillage system, on the aggregates and organic matter of a Rhodic Ferralsol. The experiment was performed in the 2006/2007, 2007/2008 and 2008/2009 growing seasons. Congo signal grass (Urochloa ruziziensis, grain sorghum (Sorghum bicolor and sorghum mixed with brachiaria were cropped in the fall-winter to consist the main plots. In the spring, millet (Pennisetum glaucum, 'Cober Crop' (Sorghum bicolor x Sorghum sudanense and Indian hemp (Crotalaria juncea were cultivated as subplots as well as a fallow treatment. Soybean was cropped in the summer, totaling 12 treatments. Cover crop dry matter and root growth were evaluated in 2006 and 2008. Soil samples were taken from 0-5 and 5-10 cm depths, after spring cover crops managing, in the first and third years. The mean weight diameter, geometric mean diameter, aggregate stability index, aggregates larger than 2 mm, organic matter and total organic carbon levels were evaluated in the samples of the third year. Millet and 'Cober Crop' showed higher dry matter production and root growth. The soil aggregation was improved by cover crop rotations before the summer growing season. The cultivation of 'Cober Crop' and millet influenced the macroaggregate formation in the superficial layers

Rodrigo Arroyo Garcia

2010-12-01

212

Trigo e Triticale em rotações de sequeiro efeitos na qualidade Wheat and triticale in crop rotations quality effects  

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Full Text Available Este trabalho resume parte dos resultados de um ensaio de rotações que decorreu durante dez anos (1986-1996 em Vila Real (Trásos-Montes. O ensaio incluiu a rotação tradicional das condições de sequeiro da região, cereal-alqueive (TA, e rotações alternativas susceptíveis de serem adoptadas nestas condições, cereal-leguminosa (TL, cereal-consociação forrageira (TC e cereal-prado de sequeiro (TP. Os cereais das rotações foram o trigo e, posteriormente, o triticale. Determinaram-se e analisaram-se as produções de grão e palha das diversas culturas e respectivos teores em nutrientes, parâmetros do solo, peso de mil grãos, peso do hectolitro e os índices de Zeleny, Queda e Pelshenke do grão de trigo. A rotação do trigo com tremocilha (leguminosa para grão induz no grão de trigo maiores valores do índice de Pelshenke e de teor em azoto; no triticale esta influência positiva da rotação com leguminosa fez-se sentir no peso de mil grãos e no peso do hectolitro. Como principais conclusões pode-se referir: alguma influência da rotação com tremocilha no conjunto dos parâmetros de qualida de do grão analisados, a influência decisiva do ano agrícola nos resultados e a importância da espécie de cereal para extracção de conclusões significativas.Results of a field trial of crop rotations conducted over a period of ten years (19861996 in Vila Real (Northeast Portugal are presented. The rotations tested were cereal-cultivated fallow (TA, traditional in rain-fed conditions of the region, and alternative rotations that could be adopted in these conditions: cereal-grain legume crop (TL, cereal-forage mixture (TC and cereal-rain-fed seeded pasture (TP. The cereals were wheat and, later, triticale. Grain, straw and aerial biomass yields, nutrient levels of crops and soil parameters were evaluated together with one thousand grain weight, hectolitre weight, Zeleny, Falling Number and Pelshenke indices of cereal grain. Wheat grain from TL rotation have the highest Pelshenke indices and nitrogen content. Triticale grain from TL rotation was the heavier and with the highest specific weight. As main conclusions we can refer the influence of the rotation with lupin in the group of the parameters of grain quality , the decisive influence of the agricultural year on the results and the importance of the cereal species to obtain significant conclusions.

Carlos Castro

2008-12-01

213

Trigo e Triticale em rotações de sequeiro efeitos na qualidade / Wheat and triticale in crop rotations quality effects  

Scientific Electronic Library Online (English)

Full Text Available SciELO Portugal | Language: Portuguese Abstract in portuguese Este trabalho resume parte dos resultados de um ensaio de rotações que decorreu durante dez anos (1986-1996) em Vila Real (Trásos-Montes). O ensaio incluiu a rotação tradicional das condições de sequeiro da região, cereal-alqueive (TA), e rotações alternativas susceptíveis de serem adoptadas nestas [...] condições, cereal-leguminosa (TL), cereal-consociação forrageira (TC) e cereal-prado de sequeiro (TP). Os cereais das rotações foram o trigo e, posteriormente, o triticale. Determinaram-se e analisaram-se as produções de grão e palha das diversas culturas e respectivos teores em nutrientes, parâmetros do solo, peso de mil grãos, peso do hectolitro e os índices de Zeleny, Queda e Pelshenke do grão de trigo. A rotação do trigo com tremocilha (leguminosa para grão) induz no grão de trigo maiores valores do índice de Pelshenke e de teor em azoto; no triticale esta influência positiva da rotação com leguminosa fez-se sentir no peso de mil grãos e no peso do hectolitro. Como principais conclusões pode-se referir: alguma influência da rotação com tremocilha no conjunto dos parâmetros de qualida de do grão analisados, a influência decisiva do ano agrícola nos resultados e a importância da espécie de cereal para extracção de conclusões significativas. Abstract in english Results of a field trial of crop rotations conducted over a period of ten years (19861996) in Vila Real (Northeast Portugal) are presented. The rotations tested were cereal-cultivated fallow (TA), traditional in rain-fed conditions of the region, and alternative rotations that could be adopted in th [...] ese conditions: cereal-grain legume crop (TL), cereal-forage mixture (TC) and cereal-rain-fed seeded pasture (TP). The cereals were wheat and, later, triticale. Grain, straw and aerial biomass yields, nutrient levels of crops and soil parameters were evaluated together with one thousand grain weight, hectolitre weight, Zeleny, Falling Number and Pelshenke indices of cereal grain. Wheat grain from TL rotation have the highest Pelshenke indices and nitrogen content. Triticale grain from TL rotation was the heavier and with the highest specific weight. As main conclusions we can refer the influence of the rotation with lupin in the group of the parameters of grain quality , the decisive influence of the agricultural year on the results and the importance of the cereal species to obtain significant conclusions.

Carlos, Castro; João, Coutinho; Nuno, Moreira; António, Crespi.

2008-12-01

214

Potassium Nutrition In Ratoon Sugarcane Under A Conservation Cropping System  

Scientific Electronic Library Online (English)

Full Text Available Ratoon sugarcane response to potassium is dependent on the environmental conditions of the region. Cropping systems that do not burn crop biomass after harvest leave crop residues on the soil, affecting the soil-plant nutrient dynamics system and fertilizer requirements. The objective of this study [...] was to evaluate the effect of potassium fertilization of first and second ratoon sugarcane crops on potassium contents in the soil, in the plant, and yield and quality of stalksin an Oxisol under a conservation cropping system. The following potassium rates were tested: 0, 27, 54, 108, and 162 kg K ha-1, arranged in a randomized block design with five replicates. The application of potassium increased soil nutrient concentrations at six months, reaching 2.87 and 2.61 mmol c dm-3 with the highest rate in the first and second ratoons, respectively. The increase in available exchangeable-K content in the soil favored a greater plant uptake of this nutrient, reaching 12.1 and 10.0 g kg-1 in the first and second ratoons, respectively. The increase in potassium absorption by plants was reflected in the production of stems; the highest yields (87.0 and 132.9 t ha-1) were obtained with the application of 162 kg K ha-1 in the first and second ratoons, respectively.

Rilner, Alves Flores; Renato, De Mello Prado; Hilário, Júnior De Almeida; Márcio Alexandre, Pancelli; Jonas Pereira, De Souza Junior; Anelisa, De Aquino Vidal Lacerda Soares.

2014-06-01

215

Applying modelling experiences from the past to shape crop systems biology : the need to converge crop physiology and functional genomics  

OpenAIRE

Functional genomics has been driven greatly by emerging experimental technologies. Its development as a scientific discipline will be enhanced by systems biology, which generates novel, quantitative hypotheses via modelling. However, in order to better assist crop improvement, the impact of developing functional genomics needs to be assessed at the crop level, given a projected diminishing effect of genetic alteration on phenotypes from the molecule to crop levels. This review illustrates a r...

Yin, X.; Struik, P. C.

2008-01-01

216

Growth and yield responses of crops and macronutrient balance influenced by commercial organic manure used as a partial substitute for chemical fertilizers in an intensive vegetable cropping system  

Science.gov (United States)

A long-term field experiment was conducted with an annual rotation of tomato-radish-pakchoi to assess the effects of a commercial organic manure (COM) used as a partial substitute for chemical fertilizers on crop yield and nutrient balance in an intensive vegetable cropping system. Four treatments as chemical fertilizers (T1), chemical fertilizers + lower rate of COM (T2), chemical fertilizers + medium rate of COM (T3), and chemical fertilizers + high rate of COM (T4) were designed in the present experiment. The supplied doses of N, P, and K were equal for all treatments. Results showed that there were no significant differences in shoot biomass and market yields of tomato, radish and pakchoi among treatments ( P > 0.05). It was found that positive P and K balance existed in the tomato-radish-pakchoi cropping system of all treatments. Compared with no manure treatment (T1), application of medium rate of COM (T3) decreased N, P runoff losses, increased N, P, K contents in crop tissues except N, P in pakchoi shoot, and lessened P, K accumulation in soils, accordingly, improved the efficiency of macronutrient. It was concluded that appropriate COM used as a partial substitute for chemical fertilizers could not only meet the crops’ nutrient requirement, but also improved the efficiency of macronutrient and remained positive balance of P and K in the intensive tomato-radish-pakchoi cropping system, which can be regarded as an effective measure for a contribution towards sustainable agriculture and a control pathway for reducing the potential risk of castoff to water environment.

Lu, H. J.; Ye, Z. Q.; Zhang, X. L.; Lin, X. Y.; Ni, W. Z.

217

Password Based Rotational Multistory Car Parking System  

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Full Text Available Parking is a big issue in thickly populated areas and in larger cities due to heavy traffic. This intended application of rotational multistory parking system effectively minimizes this issue. It results in less space and more secure parking. ATMEL microcontroller is used as main processor while LCD and motors are as complimentary components for display and rotation The model is based on circular mechanism giving low cost, less space and optimum performance. Password locking system is used to verify the object and detects number of free spaces available in the parking lot. The world has become a global market and numbers of vehicles are also increased to an uncontrollable situation. Keeping this problem the intended model is designed. Password locking system embedded in the work has made the parking of vehicles very much secure.

Nayab Suhail Hamirani

2011-12-01

218

Assessment of factors influencing groundwater-level change using groundwater flow simulation, considering vertical infiltration from rice-planted and crop-rotated paddy fields in Japan  

Science.gov (United States)

Assessing factors that influence groundwater levels such as land use and pumping strategy, is essential to adequately manage groundwater resources. A transient numerical model for groundwater flow with infiltration was developed for the Tedori River alluvial fan (140 km2), Japan. The main water input into the groundwater body in this area is irrigation water, which is significantly influenced by land use, namely paddy and upland fields. The proposed model consists of two models, a one-dimensional (1-D) unsaturated-zone water flow model (HYDRUS-1D) for estimating groundwater recharge and a 3-D groundwater flow model (MODFLOW). Numerical simulation of groundwater flow from October 1975 to November 2009 was performed to validate the model. Simulation revealed seasonal groundwater level fluctuations, affected by paddy irrigation management. However, computational accuracy was limited by the spatiotemporal data resolution of the groundwater use. Both annual groundwater levels and recharge during the irrigation periods from 1975 to 2009 showed long-term decreasing trends. With the decline in rice-planted paddy field area, groundwater recharge cumulatively decreased to 61 % of the peak in 1977. A paddy-upland crop-rotation system could decrease groundwater recharge to 73-98 % relative to no crop rotation.

Iwasaki, Yumi; Nakamura, Kimihito; Horino, Haruhiko; Kawashima, Shigeto

2014-12-01

219

Evaluation of the ECOSSE model for simulating soil carbon under short rotation forestry energy crops in Britain  

OpenAIRE

Understanding and predicting the effects of land-use change to short rotation forestry (SRF) on soil C is an important requirement for fully assessing the C mitigation potential of SRF as a bioenergy crop. There is little current knowledge of SRF in the UK and in particular a lack of consistent measured datasets on the direct impacts of land use change on soil C stocks. The ECOSSE model was developed to simulate soil C dynamics and greenhouse gas (GHG) emissions in mineral and organic so...

Dondini, Marta; Jones, Edward O.; Richards, Mark; Pogson, Mark; Rowe, Rebecca L.; Keith, Aidan M.; Perks, Mike P.; Mcnamara, Niall P.; Smith, Joanne U.; Smith, Pete

2014-01-01

220

Residual Influence of Early Season Crop Fertilization and Cropping System on Growth and Yield of Cassava  

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Full Text Available Problem statement: In assessing fertilizer effects to sustain an intensive cropping system, the residual effects of fertilizer applied to preceding maize on the growth and yield of cassava and the effects of intercropping with soybean were studied in field experiments at Ibadan, Nigeria. Approach: Maize, established in April was fertilized using either organic manure or inorganic fertilizer or a mixture of organic manure and inorganic fertilizers. Organic manure was an equal mixture of domestic waste collected from a composted refuse dumping site applied at l0 t ha-1. Inorganic fertilizer was 150kg N supplied as urea and 50 kg P ha-1 as Single Super phosphate fertilizer. The mixture of organic and inorganic fertilizer treatment was 5 tonnes organic manure and 75kg N+25 kg P ha-1. Cassava was established in June and soybean planted in July, after harvesting maize. Results: Organic fertilizer treatment gave the tallest plants of 53 cm. Plants from sole inorganic fertilizer and from a mixture of organic and inorganic fertilizers had comparable heights but were significantly lower than plants from sole organic fertilizer application. Organic fertilizer application gave the highest seed yield of 481 kg ha-1 that was significantly higher than 380 kg ha-1 observed from a mixture of organic and inorganic fertilizers. Stover yield followed the same trend as seed yield. Cassava plant height was increased with fertilization but was reduced with intercropping. Sole organic fertilization had the tallest plants. Plant leaf area was neither significantly affected by fertilizer type nor cropping system. Fresh root yield was significantly reduced by 16% with soybean intercropping. Sole organic fertilizer application gave the highest yields of 22 tons ha-1 in sole crop and 18 tons ha-1 in intercrop with soybean. Conclusion: Cultivating an early season maize crop, followed by a cassava-soybean intercrop is more favored with application of 10 tons ha-1 organic fertilizer.

E. A. Makinde

2008-01-01

221

Efecto de la rotación de cultivos y prácticas de labranza sobre las fracciones de la materia orgánica del suelo / TILLAGE SYSTEM AND CROP ROTATION EFFECTS ON SOIL ORGANIC MATTER FRACTIONS / EFEITO DA ROTAÇÃO DE CULTIVOS E PRÁTICAS DE LAVRAGEM SOBRE AS FRAÇÕES DA MATÉRIA ORGÂNICA DO SOLO  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in portuguese As práticas de lavragem e rotação de cultivos podem modificar a matéria orgânica do solo (MOS). Um estudo conduzido por sete anos, onde se incluíram lavragem e rotação de cultivos, foi utilizado para avaliar o efeito do manejo do solo sobre as diferentes frações do C e N. O experimento foi localizad [...] o em Turén, estado Portuguesa, Venezuela, e incluiu dois sistemas de lavragem, lavragem convencional (LC) e semeadura direta (SD), e duas rotações de cultivos, milho-algodão (MA) e milho-feijão (MF). Amostras de solo foram coletadas a três profundidades e se analisou o C (COT) e N orgânico total (NOT), C (MMC) e N (MMN) da massa microbiana, C e N mineralizável (Cmin e Nmin), N lábil potencialmente mineralizável (N1) e sua taxa de decomposição (kl). As mudanças observadas em COS e NOS em resposta à lavragem e à rotação de cultivos foram relacionadas com a quantidade e qualidade de resíduos de plantas que retornam ao solo, mas não com a sua distribuição no perfil do solo, com exceção da MO mineralizável. Este estudo demonstra a importância da MMC, MMN e da mineralização do C e N como índices para conhecer a dinâmica da MOS em uma zona tropical. Por outra parte, o N1 pode ser usado como indicador da capacidade do solo de liberar N da MOS. Abstract in spanish Las prácticas de labranza y rotación de cultivos pueden modificar la materia orgánica del suelo (MOS). Un estudio conducido por siete años, donde se incluyeron labranza y rotación de cultivos, fue utilizado para evaluar el efecto del manejo de suelo sobre las diferentes fracciones de C y N. El exper [...] imento fue localizado en Turén, estado Portuguesa, Venezuela, e incluyó dos sistemas de labranza, labranza convencional (LC) y siembra directa (SD), y dos rotaciones de cultivos, maíz-algodón (MA) y maíz-fríjol (MF). Muestras de suelo fueron colectadas a tres profundidades y se analizó el C (COT) y N orgánico total (NOT), C (MMC) y N (MMN) de la masa microbiana, C y N mineralizable (Cmin y Nmin), N lábil potencialmente mineralizable (N1) y su tasa de descomposición (k l). Los cambios observados en COT y NOT en respuesta a la labranza y a la rotación de cultivos fueron relacionados con la cantidad y calidad de residuos de planta que regresan al suelo, pero no con su distribución en el perfil del suelo, con excepción de la MO mineralizable. Este estudio demuestra la importancia de la MMC, MMN y de la mineralización de C y N como índices para conocer la dinámica de la MOS en una zona tropical. Por otra parte, el N1 puede ser usado como indicador de la capacidad del suelo de liberar N de la MOS. Abstract in english Cultivation practices such as tillage and crop rotation can modify soil organic matter (MOS). A crop rotation-tillage study was conducted for seven years in order to evaluate the effects on the different pools of C and N. The experiment was located in Turén, Portuguesa State, Venezuela, with two til [...] lage systems: conventional tillage (CT), and no tillage (NT) and two crop rotations, corn-cotton (CC), and corn-bean (CB). Soil samples were collected at three depths and analyzed for total organic C (COT) and N (TON), microbial biomass C (MMC) and N (MMN), mineralized C and N (Cmin and Nmin), and potentially mineralized labile N (N1) and its decay rate (k l). The changes observed in COT and NOT in response to tillage and rotation were related to the quantity and quality of plant residues returned to the soil, but not to their distribution in the soil profile, with exception of MO mineralization. This study shows the importance of the MMC, MMN, C and N mineralization as indexes of MOS dynamics in a tropical region. On the other hand, N1 can be used as an indicator of the relative soil capacity to release N from MOS.

Yusmary, Espinoza; Zenaida, Lozano; Lorenzo, Velásquez.

2007-08-01

222

The perspective crops for the bioregenerative human life support systems  

Science.gov (United States)

The perspective crops for the bioregenerative human life support systems V.I. Polonskiy, J.E. Polonskaya aKrasnoyarsk State Agrarian University, 660049, Krasnoyarsk, Russia In the nearest future the space missions will be too long. In this case it is necessary to provide the crew by vitamins, antioxidants, and water-soluble dietary fibers. These compounds will be produced by higher plants. There was not enough attention at present to increasing content of micronutrients in edible parts of crops candidates for CELSS. We suggested to add the new crops to this list. 1. Barley -is the best crop for including to food crops (wheat, rice, soybean). Many of the health effects of barley are connected to dietary fibers beta-glucan of barley grains. Bar-ley is the only seed from cereals including wheat with content of all eight tocopherols (vitamin E, important antioxidant). Barley grains contain much greater amounts of phenolic compounds (potential antioxidant activities) than other cereal grains. Considerable focus is on supplement-ing wheat-based breads with barley to introduce the inherent nutritional advantages of barley flour, currently only 20We have selected and tested during 5 generations two high productive barley lines -1-K-O and 25-K-O. Our investigations (special breeding program for improving grain quality of barley) are in progress. 2. Volatile crops. Young leaves and shoots of these crops are edible and have a piquant taste. A lot of organic volatile compounds, oils, vitamins, antioxidants are in their biomass. These micronutrients are useful for good appetite and health of the crew. We have investigated 11 species: basil (Ocimum basilicum), hyssop (Hyssopus officinalis), marjoram (Origanum majorana), sweet-Mary (Melissa officinalis), common thyme (Thymus vulgaris), creeping thyme (Thymus serpyllum), summer savory (Satureja hortensis), catnip (Nepeta cataria), rue (Ruta graveolens), coriander (Coriandrum Ativum), sulfurwort (Levisticum officinale). These plants were grown under artificial light conditions from 5 to 7 months. All crops were cut periodically in every month. On the base of our investigations it is possible to recommend for using in CELSS the next crops: marjoram, sweet-Mary and common thyme. The micronutrients containing in barley and above mentioned volatile crops will be useful for good appetite and health of the crew.

Polonskiy, Vadim; Polonskaya, Janna

223

Effect of Tree Prunings on Soil Fertility and Crop Yield in Alley Cropping System  

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Full Text Available The study was conducted to find the impact of incorporation of green prunings from Samanea saman and Dalbergia sissoo in alley cropping system on soil fertility and subsequently yields of rice and wheat. Three treatments used were, 100 kg N ha -1 from 15N ammonium sulphate, 80 kg N ha -1 provided through prunings either from D. sissoo or S. saman plus 20 kg N ha -1 from 15N ammonium sulphate. Grain and straw yields of rice were increased by 23.8 and 32.1%. %15N atom excess (a. e. and percent nitrogen derived from fertilizer were higher in treatment receiving 100% chemical fertilizer compared to those with tree prunings. Nitrogen contribution of tree prunings to rice yield was 51.3% in D. sissoo and 54.1% in S. saman. The positive effect of pruning was observed in P and K uptake by rice grain and straw. Residual effect of added prunings in succeeding wheat crop was also noticed for both in D. sissoo prunings (11.7% and S. saman prunings (11.3%. In wheat crop , %15N (a. e. and %Ndff were higher in 100% chemical fertilizer treatment compared to the residues of those with tree prunings. Nitrogen availability from the residues of tree prunings for wheat crop was 17.72 to 22.54%. P and K uptake in wheat were also more in previously tree pruning treated plots, as compared to the untreated ones. Improvement of soil fertility were observed due to application of tree prunings. Total N, available P, K and organic C were increased, resulting in good soil health, due to prunings.

M. A. Haque

2001-01-01

224

Systems Approach to Crop Rotation Research: Guidelines and Challenges  

Science.gov (United States)

The wheat growing area of the PNW is a unique region in that precipitation ranges from < 300 mm to 600 mm. The majority of the precipitation occurs during the winter months, which is ideal for winter wheat production. Because of this, growers produce winter wheat as often as possible and until the...

225

Life cycle assessment of a willow bioenergy cropping system  

International Nuclear Information System (INIS)

The environmental performance of willow biomass crop production systems in New York (NY) is analyzed using life cycle assessment (LCA) methodology. The base-case, which represents current practices in NY, produces 55 units of biomass energy per unit of fossil energy consumed over the biomass crop's 23-year lifetime. Inorganic nitrogen fertilizer inputs have a strong influence on overall system performance, accounting for 37% of the non-renewable fossil energy input into the system. Net energy ratio varies from 58 to below 40 as a function of fertilizer application rate, but application rate also has implications on the system nutrient balance. Substituting inorganic N fertilizer with sewage sludge biosolids increases the net energy ratio of the willow biomass crop production system by more than 40%. While CO2 emitted in combusting dedicated biomass is balanced by CO2 adsorbed in the growing biomass, production processes contribute to the system's net global warming potential. Taking into account direct and indirect fuel use, N2O emissions from applied fertilizer and leaf litter, and carbon sequestration in below ground biomass and soil carbon, the net greenhouse gas emissions total 0.68 g CO2 eq. MJbiomassproduced-1. Site specific parameters such as soil carbon sequestration could easily offset these emissions resulting in a net reduction of greenhouse gases. Assuming reasonable biomass transportation dsuming reasonable biomass transportation distance and energy conversion efficiencies, this study implies that generating electricity from willow biomass crops could produce 11 units of electricity per unit of fossil energy consumed. Results form the LCA support the assertion that willow biomass crops are sustainable from an energy balance perspective and contribute additional environmental benefits

226

Present and potential weed infestation of spring cereals in different cropping system  

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Full Text Available This paper presents the results of investigations on the weed infestation and vertical distribution of weed seed bank in rendzina under spring cereals cultivation in crop rotations and monoculture. Used herbicides (MCPA and fenoxaprop-P-etylu decreased the number of weeds and species composition in comparison with harrowing. In the soil layer of 0-25 cm used in the monoculture there was found about 22,9% weed seeds more than in crop rotation. In the canopy of spring cereals the following weeds dominated: in crop rotation - Chenopodium album, Echinochloa crus-galli and Veronica persica; and in monoculture - Stellaria media, Galium aparine and Chenopodium album. In the soil layer of 0-25 cm used in crop rotation and monoculture the following weed seeds dominated : Amaranthus retroflexus, Chenopodium album and Stellaria media.

Andrzej Weso?owski

2001-06-01

227

Fate of nitrogen from mineral fertilizer and liquid manure over a two-year crop rotation  

International Nuclear Information System (INIS)

Nitrogen-15-labelled fertilizer was used to gain a better understanding of fertilizer-N uptake by crops in the year of application, the immobilization of applied N in the soil, fertilizer N uptake by a subsequent crop, and fertilizer-N leaching to groundwater. Fertilizer-N-utilization values for winter wheat (planted in the first year) were 15 to 36%, and 27 to 63% of the applied N was immobilized in the soil. Losses of fertilizer N by leaching to groundwater were not significant. At harvest of the winter wheat, between 50% and 82% of applied fertilizer N was accounted for in total. Unaccounted-for N was probably lost by volatilization. Only a few kilograms of applied N were taken up by the succeeding cover crop and corn. (author)

228

Crop rotation as a factor differentiating the intensity of the diseases of field pea (Pisum sativum L.  

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Full Text Available The research was conducted in the years 1998-2001. The aim of the research was to determine the health of the field pea cv. Kormoran grown in four various crop rotations and to determine the patogens causing the root-rot. On the pea plants the following diseases were found: root rot (complex of fungi, ascochyta blight (Ascochyta pisi, Phoma pinodella, Mycospaerella pinodes and fusarium foot rot (Fusarium spp.. All the diseases occurred in the highest intensity on the pea cultivated in three-field crop rotation without manure. The weather conditions affected the intensity of the diseases. From the roots of seedlings with the symptoms of root rot 44,7% of fungi with pathogenic potential in relation to pea were obtained. The most commonly isolated were Fusarium oxysporum (26,7% of all isolates, Rhizoctonia solani (10,7%, F.solani (3,3%, F.avenaceum (2,7% and F.equiseti (1,3%. From the infected root necks, 55,3% of potential pathogens of field pea were obtained. Among the isolates the most commonly found was F.oxysporum (31,1% of all isolates. Other fungi of the Fusarium genus constituted 15,4% of isolates, R.solani 7,0%, and Sclerotinia sclerotiorum 1,8%.

Tomasz P. Kurowski

2002-06-01

229

Soilless cultivation system for functional food crops  

International Nuclear Information System (INIS)

This soilless cultivation system is based on the fertigation system and cultivation technologies using Functional Plant Cultivation System (FPCS). EBARA Japan has been studying on the cultivation conditions in order to enhance the function of decease risk reduction in plants. Through the research and development activities, EBARA found the possibilities on the enhancement of functions. Quality and quantity of the products in term of bioactive compounds present in the plants may be affected by unforeseen environmental conditions, such as temperature, strong light and UV radiation. The main objective to develop this system is, to support? Functional Food Industry? as newly emerging field in agriculture business. To success the system, needs comprehensive applying agriculture biotechnologies, health biotechnologies and also information technologies, in agriculture. By this system, production of valuable bioactive compounds is an advantage, because the market size of functional food is increasing more and more in the future. (Author)

230

Perturbation theory approach to rotational tunneling systems  

Scientific Electronic Library Online (English)

Full Text Available Diagrammatic perturbation theory is used to consider the problem of the coupling of a molecular group libration to the lattice vibrations in solids exhibiting rotational tunneling detected by inelastic neutron scattering. The technique is applied to a molecular group of symmetry C3 in presence of th [...] e hindering potential of the solid. The spectral density for transitions between rotational tunneling states in the ground librational level is obtained as a function of temperature. Low temperature results are presented for di erent phonon spectrum parameters. They are used to check the assumption that this coupling is the origin of the peculiar behaviour of the line shifting and broadening as a function of temperature in the INS spectra of such systems.

Luciano T., Peixoto.

2000-03-01

231

NEW TRENDS IN AGRICULTURE - CROP SYSTEMS WITHOUT SOIL  

Directory of Open Access Journals (Sweden)

Full Text Available The paper studied new system of agriculture - crop systems without soil. The culture systems without soil can be called also the hydroponic systems and now in Romania are not used only sporadically. In other countries (USA, Japan, the Netherlands, France, UK, Denmark, Israel, Australia, etc.. they represent the modern crop technology, widely applied to vegetables, fruits, fodder, medicinal plants and flowers by the experts in this area. In the world, today there are millions of hectares hydroponics, most of the vegetables, herbs, fruits of hypermarkets are coming from the culture systems without soil. The process consists of growing plants in nutrient solutions (not in the ground, resorting to an complex equipment, depending on the specifics of each crop, so that the system can be applied only in the large farms, in the greenhouses, and not in the individual households. These types of culture systems have a number of advantages and disadvantages also. Even if today's culture systems without soil seem to be the most modern and surprising technology applied in plant growth, the principle is very old. Based on him were built The Suspended Gardens of the Semiramis from Babylon, in the seventh century BC, thanks to him, the population from the Peru”s highlands cultivates vegetables on surfaces covered with water or mud. The peasant households in China, even today use the millenary techniques of the crops on gravel. .This hydroponic agriculture system is a way of followed for Romanian agriculture too, despite its high cost, because it is very productive, ecological, can cover, by products, all market demands and it answer, increasingly, constraints of urban life. The concept of hydroponics agriculture is known and appreciated in Romania also, but more at the theory level.

Ioan GRAD

2014-04-01

232

A STELLA Model to Estimate Water and Nitrogen Dynamics in a Short-Rotation Woody Crop Plantation.  

Science.gov (United States)

Although short-rotation woody crop biomass production technology has demonstrated a promising potential to supply feedstocks for bioenergy production, the water and nutrient processes in the woody crop planation ecosystem are poorly understood. In this study, a computer model was developed to estimate the dynamics of water and nitrogen (N) species (e.g., NH-N, NO-N, particulate organic N, and soluble organic N [SON]) in a woody crop plantation using STELLA (tructural hinking and xperiential earning aboratory with nimation) software. A scenario was performed to estimate diurnal and monthly water and N variations of a 1-ha mature cottonwood plantation over a 1-yr simulation period. A typical monthly variation pattern was found for soil water evaporation, leaf water transpiration, and root water uptake, with an increase from winter to summer and a decrease from summer to the following winter. Simulations further revealed that the rate of soil water evaporation was one order of magnitude lower than that of leaf water transpiration. In most cases, the relative monthly water loss rates could be expressed as evapotranspiration > root uptake > percolation > runoff. Leaching of NO-N and SON depended not only on soil N content but also on rainfall rate and duration. Leaching of NO-N from the cottonwood plantation was about two times higher than that of SON. The relative monthly rate of N leaching was NO-N > SON > NH-N. This study suggests that the STELLA model developed is a useful tool for estimating water and N dynamics from a woody crop plantation. PMID:25602335

Ouyang, Ying; Zhang, Jiaen; Leininger, Theodor D; Frey, Brent R

2015-01-01

233

The impact of the cropping system management on soil erosion and fertility in Northeastern Romania  

International Nuclear Information System (INIS)

The mass of total carbon from Cambic Chernozem in the Moldavian Plain has recorded significant increases at higher than N140 P100 rates, in organo-mineral fertilization and in 4-year crop rotation, which included melioration plants of perennial grasses and legumes. In maize continuous cropping and wheat-maize rotation, very significant values of the carbon content were found only in the organo-mineral fertilization, in 4-year crop rotations + reserve field cultivated with perennial legumes and under N140 P100 fertilization. In comparison with 4-year crop rotations, in wheat-maize rotation with melioration plants (annual and perennial legumes and perennial grasses), the mean carbon content from soil has diminished from 18.6 to 16.4 C, g.Kg-1 and the content in mobile phosphorus decreased from 51.6 to 36.8 P-Al, mg.kg-1. The 40 year use of 3 and 4-year crop rotations has determined the increase in total carbon mass and mobile phosphorus from soil by 10% (1.7 C g-kg-1) and 31%, respectively (11.8 P-Al mg.kg-1), against maize continuous cropping. (Author) 6 refs.

234

Use of the crown competition factor concept to select clones and spacings for short-rotation woody crops.  

Science.gov (United States)

Plantation spacing and rotation age are interrelated critical factors in optimizing production of short-rotation woody crops (SRWC). Different genotypes have different spacing and rotation-age optima. I have developed a method for estimating the optimum for new Populus clones based on a modification of the crown competition factor (CCF) concept, which was originally developed for conventional forestry practices with older trees. Measurements of as few as 100 trees of a new clone over a relatively short time period could be used to predict the optimum spacing and rotation age combinations for that clone. The technique could also be used to quantify basic differences in crown architecture and yield physiology among genotypes. One set of at least 20 trees is planted at an open-grown spacing and measured annually for crown and basal stem diameters. The regression of crown diameter on stem diameter is used to calculate the land area that would be occupied per open-grown tree at various stem diameters. This allows prediction of the spacing needed to reach the minimum density for maximum stand growth at a given age or stem size. A second set of 80 measurement trees is planted in a closely spaced set of Nelder arcs to force overstocking within the first few years of growth. Productivity measurements on these trees establish the upper limit on CCF for maximum stand growth. The data are then used to calculate the best spacing and rotation age combination for a new clone. Application of this model may lead to a better understanding of the productive advantages of the sylleptic branch habit, different branch angles and seasonal growth rates, different carbon allocation strategies, and responses to competition. PMID:14967657

Hall, R. B.

1994-01-01

235

Long-term rice-based cropping system effects on near-surface soil compaction  

Directory of Open Access Journals (Sweden)

Full Text Available Irrigated rice (Oryza sativa L. production is as-sociated with frequent cycling between anaero-bic and aerobic conditions, which can lead to a greater rate of soil organic matter (SOM de-composition, thus potentially increasing soil bulk density (BD over time. A study was con-ducted in the Mississippi River Delta region of eastern Arkansas, USA to evaluate the long-term effects of rice-based crop rotations, tillage [conventional tillage (CT and no-tillage (NT], soil fertility regime (optimal and sub-optimal, and soil depth (0-10 and 10-20 cm after 10 years of consistent management on near-surface soil compaction, as measured by BD. Soil BD was greater under NT than CT in the top 10 cm, but was similar between NT and CT in the 10- to 20-cm depth interval. Soil BD differed among common rice-based cropping systems with corn, soybean, and winter wheat, but few consistent trends were evident. It appears that, even after 10 years of continuous CT or NT rice production on a silt-loam soil, substantially increased near-surface soil BD has not occurred to the point where soil compaction would be a likely culprit responsible for a reduced early season stand establishment or crop yield differences among rice-based copping systems.

Kristofor R. Brye

2011-05-01

236

Prototype Geographic Information Systems Mapping of Crop Products Featured Local  

Directory of Open Access Journals (Sweden)

Full Text Available Local featured program in Indonesia cannot be separated entirely from commodity strategic bases. Until in 2006, agricultural development formulation showed indicative targets for featured crops commodity production. The problem of food security is forming of farmer’s independence to protect local resources in efficiently and optimally, so these resources can be more utilized. It can be achieved by assist of information technologies and communication in forming of Geographic Information System (GIS to support consistency of food security in Indonesia. This research designs prototype geographic information system in order to conduct the accurate mapping and to know the local featured crops production in Indonesia. This level is conducted for documentation and mapping of agricultural products which is the local featured production. This documentation requires the usage of potential physical, economic, social and cultural environment by the utilization of information technology and communication, which have the ability of relevancy and accessibility of reliable information.

Teddy Oswari

2013-06-01

237

In vitro mutation system for crop improvement  

International Nuclear Information System (INIS)

Biotechnology based on plant tissue culture is complementary to conventional breeding technologies, not a substitute for them. Effective incorporation of new biotechnologies into plant breeding programmes is dependent on the plant species and the breeding objectives. Tissue culture techniques that ensure genetic stability (e.g. shoot tip and nodal cultures) are particularly useful for in vitro mutation induction and mutant plant regeneration. Direct organogenesis of adventitious buds and/or somatic embryogenesis on cultured explants offers a unique potential to dissolve chimerism and to produce homohistont mutants. In mutation breeding, non-heritable somaclonal variation should be avoided in order to minimize complications in the selection and genetic stability of mutants. Application of mutagens during in vitro culture requires certain modification, depending on the explant and the mutagen used. The advantages are large populations of individuals (propagula, cells and tissue) which can be treated before regeneration into intact plants. Experience with plant tissue culture shows several disadvantages in this system of mutation breeding. The main limitations are inadequate techniques for early screening and in vitro selection. Too little is known about the plant developmental processes and host-pathogen interaction to permit the breeder to design an effective means of selecting desirable mutants. (author). 25 refs, 9 figs

238

An Ultrasonic System for Weed Detection in Cereal Crops  

OpenAIRE

Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance ...

Dionisio Andújar; Roland Gerhards; Martin Weis

2012-01-01

239

Counter-Rotating Tandem Motor Drilling System  

Energy Technology Data Exchange (ETDEWEB)

Gas Technology Institute (GTI), in partnership with Dennis Tool Company (DTC), has worked to develop an advanced drill bit system to be used with microhole drilling assemblies. One of the main objectives of this project was to utilize new and existing coiled tubing and slimhole drilling technologies to develop Microhole Technology (MHT) so as to make significant reductions in the cost of E&P down to 5000 feet in wellbores as small as 3.5 inches in diameter. This new technology was developed to work toward the DOE's goal of enabling domestic shallow oil and gas wells to be drilled inexpensively compared to wells drilled utilizing conventional drilling practices. Overall drilling costs can be lowered by drilling a well as quickly as possible. For this reason, a high drilling rate of penetration is always desired. In general, high drilling rates of penetration (ROP) can be achieved by increasing the weight on bit and increasing the rotary speed of the bit. As the weight on bit is increased, the cutting inserts penetrate deeper into the rock, resulting in a deeper depth of cut. As the depth of cut increases, the amount of torque required to turn the bit also increases. The Counter-Rotating Tandem Motor Drilling System (CRTMDS) was planned to achieve high rate of penetration (ROP) resulting in the reduction of the drilling cost. The system includes two counter-rotating cutter systems to reduce or eliminate the reactive torque the drillpipe or coiled tubing must resist. This would allow the application of maximum weight-on-bit and rotational velocities that a coiled tubing drilling unit is capable of delivering. Several variations of the CRTDMS were designed, manufactured and tested. The original tests failed leading to design modifications. Two versions of the modified system were tested and showed that the concept is both positive and practical; however, the tests showed that for the system to be robust and durable, borehole diameter should be substantially larger than that of slim holes. As a result, the research team decided to complete the project, document the tested designs and seek further support for the concept outside of the DOE.

Kent Perry

2009-04-30

240

Black locust (Robinia pseudoacacia L. Short-Rotation Crops under Marginal Site Conditions  

Directory of Open Access Journals (Sweden)

Full Text Available The improvement of the reliability of renewable resources and the decline in reserves offossile raw material in the coming decades will lead to increasing demands for wood material andconsequently to a greater role of short rotation forestry (SRF. Particular efforts have been made inEurope to substitute fossils with renewables, in this context the proportion of renewable energy shouldbe increased to 20% by 2020. SRF can be provide relatively high dendromass (biomass incrementrates if the short rotation tree plantations are grown under favourable site conditions and for anoptimum rotation length. However, in many countries only so-called marginal sites are available forsetting up tree plantations for energy purpose. For SRF under marginal site conditions black locust(Robinia pseudoacacia L. can be considered as one of the most promising tree species thanks to itsfavourable growing characteristics. According to a case study presented in the paper black locust canproduce a Mean Annual Increment (MAI of 2.9 to 9.7 oven-dry tons ha–1 yr–1 at ages between 3 and7 years using a stocking density of 6667 stems ha–1. On the base of the presented results and accordingto international literature the expected dendromass volume shows great variation, depending upon site,species, their cultivars, initial spacing and length of rotation cycle.

RÉDEI, Károly

2011-01-01

241

THE INFLUENCE OF MINIMUM TILLAGE SYSTEMS UPON THE SOIL PROPERTIES, YIELD AND ENERGY EFFICIENCY IN SOME ARABLE CROPS  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents the influence of the conventional ploughing tillage technology in comparison with the minimum tillage, upon the soil properties, weed control, yield and energy efficiency in the case of maize (Zea mays L., soyabean (Glycine hispida L. and winter wheat (Triticum aestivum L. in a three years crop rotation. For all cultures within the crop rotation, the weed encroachment is maximum for the disc harrow and rotary harrow soil tillage, followed by the chisel and paraplow. The weed encroachment is minimum for the conventional ploughing tillage technology. The results of investigations showed that the yield is a conclusion soil tillage systems influence on soil properties, plant density assurance and on weed control.

Teodor RUSU

2006-05-01

242

Changes in bird community composition in response to growth changes in short-rotation woody crop planting  

International Nuclear Information System (INIS)

Hybrid poplar established as intensively managed short-rotation woody crops (SRWC) on former agricultural lands can provide habitat for wildlife. Studies of bird use of SRWC for nesting and during fall migration have shown that the numbers and kinds of breeding birds using mature plantings of hybrid poplar are similar to natural forested lands. In Minnesota, the number of species of breeding birds using habitat provided by clonal-trial plantings and young larger-scale plantings (12-64 ha) of hybrid poplar were initially most similar to those using grasslands and row-crops. As the plantings approached canopy closure, successional species became predominant. In the Pacific Northwest, breeding bird composition and density were very similar for mature plantings and forested areas; however, fall migrants were found primarily in forested areas. In the Southeast, preliminary comparisons of breeding bird use of plantings of sweetgum and sycamore with naturally regenerating forests of different ages and sizes and vegetation structure are showing no size effect on use. As with hybrid poplar, species use of the more mature plantings of sweetgum and sycamore was most similar to that of natural forests. (author)

243

Vibration diagnostic system for rotating machinery  

International Nuclear Information System (INIS)

A new system has been developed for early detecting and analyzing mechanical abnormalities occuring in motors and pumps in nuclear power plants. It is so designed as to detect and diagnose the abnormalities by monitoring and analyzing the vibration of rotating machines. Sham examinations were performed on vertical pumps and horizontal volute pumps. Abnormalities assumed to occur practically were intentionally given to the machines; the relation between the abnormality and failures and their specific features were investigated; the results were reflected upon the algorithm for abnormality diagnosis. With the system manufactured in trial, tests were made on a pump constructed for experiments, and reliability tests were made at an actual plant. A firm belief on its practicability has been established. (author)

244

Cropping Systems to Improve Carbon Sequestration for Mitigation of Climate Change  

Directory of Open Access Journals (Sweden)

Full Text Available The recent trend of an increase in the concentration of greenhouse gases (GHGs in the atmosphere has led to an ele-vated concern and urgency to adopt measures for carbon (C sequestration to mitigate the climate change. Among all GHGs, carbon dioxide (CO2 is the most important one which occurs in the greatest concentration and has the strong-est radiative forcing among all. Reducing the release of CO2 to the atmosphere through “green energy” technologies or fossil fuel energy alternatives, such as wind, solar and hydraulic energies, is a major challenge. However, removal of atmospheric CO2 by terrestrial ecosystems via C sequestration and converting the sequestered C into the soil organic C has provided a great opportunity for shifting GHG emission to mitigate the climate change. Soil is an ideal reservoir for storage of organic C since soil organic C has been depleted due to land misuse and inappropriate management through the long history. To optimize the efficiency of C sequestration in agriculture, cropping systems, such as crop rotation, intercropping, cover cropping, etc., play a critical role by influencing optimal yield, total increased C sequestered with biomass, and that remained in the soil. As matter of fact, soil C sequestration is a multiple purpose strategy. It restores degraded soils, enhances the land productivity, improves the diversity, protects the environment and reduces the enrichment of atmospheric CO2, hence shifts emission of GHGs and mitigates climate change.

Qingren Wang

2010-09-01

245

Free convection MHD flow in rotating system  

International Nuclear Information System (INIS)

An attempt to analyse the unsteady free convection MHD flow in a rotating frame of reference has been made. The response of oscillating plate temperature on velocity and skin friction is discussed with respect to Hall and rotation parameters. From the analysis it is found that velocity and skin friction increase with Hall parameter and decrease with rotation. (author). 9 refs

246

Statistical modeling of yield and variance instability in conventional and organic cropping systems  

Science.gov (United States)

Cropping systems research was undertaken to address declining crop diversity and verify competitiveness of alternatives to the predominant conventional cropping system in the northern Corn Belt. To understand and capitalize on temporal yield variability within corn and soybean fields, we quantified ...

247

Development of an unmanned agricultural robotics system for measuring crop conditions for precision aerial application  

Science.gov (United States)

An Unmanned Agricultural Robotics System (UARS) is acquired, rebuilt with desired hardware, and operated in both classrooms and field. The UARS includes crop height sensor, crop canopy analyzer, normalized difference vegetative index (NDVI) sensor, multispectral camera, and hyperspectral radiometer...

248

Cotton as a Rotation Crop for the Management of Meloidogyne arenaria and Sclerotium rolfsii in Peanut  

OpenAIRE

The value of cotton (Gossypium hirsutum cv. Deltapine 90) in rotation with peanut (Arachis hypogaea cv. Florunner) for the management of root-knot nematode (Meloidogyne arenaria) and southern blight (Sclerotium rolfsii) was studied for 6 years in a field at the Wiregrass Substation in southeast Alabama. Peanut yields following either 1 or 2 years of cotton (C-P and C-C-P, respectively) were higher than those of peanut monoculture without nematicide [P(-)]. At-plant application of aldicarb to ...

Rodri?guez-ka?bana, R.; Robertson, D. G.; Wells, L.; Weaver, C. F.; King, P. S.

1991-01-01

249

Black locust (Robinia pseudoacacia L.) Short-Rotation Crops under Marginal Site Conditions  

OpenAIRE

The improvement of the reliability of renewable resources and the decline in reserves offossile raw material in the coming decades will lead to increasing demands for wood material andconsequently to a greater role of short rotation forestry (SRF). Particular efforts have been made inEurope to substitute fossils with renewables, in this context the proportion of renewable energy shouldbe increased to 20% by 2020. SRF can be provide relatively high dendromass (biomass) incrementrates if the sh...

Re?dei, Ka?roly; Csiha, Imre; Keseru?, Zsolt

2011-01-01

250

Black Locust (Robinia Pseudoacacia L.) short-rotation energy crops in Hungary: a review  

OpenAIRE

The importance of the establishment of short-rotation tree plantations for fuel production has been of international interest for many years. In this context, in Hungary, these plantations have been conducted for a long time. In this country, the black locust (Robinia pseudoacacia L.) is one of the most important stand-forming tree species, covering approximately 23% of the forested land (410 000 ha) and providing about 19% of the annual timber output. This paper describes an e...

Re?dei, Ka?roly; Veperdi, Irina; Tome?, Margarida; Soares, Paula

2010-01-01

251

Climate variability effects on summer cropping systems on the Iberian Peninsula  

OpenAIRE

Climate variability and changes in the frequency of extremes events have a direct impact on crop yield and damages. Climate anomalies projections at monthly and yearly timescale allows us for adapting a cropping system (crops, varieties and management) to take advantage of favorable conditions or reduce the effect of adverse conditions. The objective of this work is to develop indices to evaluate the effect of climatic variability in summer cropping systems of Iberian Peninsula, in an attempt...

Ruiz Ramos, Margarita

2012-01-01

252

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

OpenAIRE

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 ...

Carr, Patrick M.; Liebig, Mark A.; Gramig, Greta G.

2013-01-01

253

Yield of cotton/cowpea and sunflower/cowpea crop rotation systems during the reclamation process of a saline-sodic soil / Produtividade de sistemas de rotação algodão/ feijão-de-corda e girassol/ feijão-de-corda durante o processo de recuperação de um solo salino-sódico  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O objetivo deste trabalho foi avaliar o uso de subsolagem, gesso agrícola e matéria orgânica, associados ao cultivo de algodão, girassol e feijão-de-corda em sistemas de rotação, visando à recuperação e o aproveitamento de um solo salino-sódico. Os tratamentos foram dispostos em um delineamento em b [...] locos casualizados, em parcelas subdivididas, com quatro repetições, durante dois ciclos. As parcelas foram formadas pelos tratamentos: T1. Subsolagem (S); T2. S + 20 Mg ha-1 de gesso (G); T3. S + 40 Mg ha-1 de matéria orgânica (MO); T4. S + 10 Mg ha-1 de G + 20 Mg ha-1 de MO; T5. S + 20 Mg ha-1 de G + 40 Mg ha-1 de MO, e as subparcelas corresponderam às rotações culturais algodão feijão-de-corda (AL/FC) e girassol feijão-de-corda (GI/FC). O emprego dos corretivos contribuiu para a diminuição dos níveis de salinidade e sodicidade do solo. O algodão não apresentou nenhuma resposta à aplicação dos tratamentos, enquanto a cultura do girassol foi favorecida pela aplicação de corretivos apenas no segundo ciclo. As maiores produtividades do feijão-de-corda no tratamento T5, no ciclo de 2009/2010, são indicativos de que as maiores doses de gesso e de matéria orgânica aplicadas neste tratamento aceleraram o processo de recuperação. Para os demais tratamentos com corretivos, verificou-se efeito benéfico para essa cultura apenas no segundo ciclo de produção, quando os valores se igualaram ao T5. Abstract in english The objective of this study was to evaluate the use of subsoiling, gypsum and organic matter associated with the cultivation of cotton, sunflower and cowpea in crop rotation, seeking the reclamation and use of a saline-sodic soil. The treatments were arranged in a randomized block design in split pl [...] ots with four replications, during two crop cycles (2009/2010 and 2010/2011). The plots were formed by the treatments: T1. Subsoiling (S); T2. S + 20 Mg ha-1 of gypsum; T3. S + 40 Mg ha-1 of organic matter; T4. S + 10 Mg ha-1 of gypsum + 20 Mg ha-1 of organic matter; T5. S + 20 Mg ha-1 of gypsum + 40 Mg ha-1 of organic matter and the sub-plots consisted of the cotton-cowpea (C/CP) and sunflower-cowpea (S/CP) crop rotation. The use of gypsum and organic matter contributed to decrease the soil salinity and sodicity. Cotton was not affected by the treatments, while the sunflower crop was favored by the application of amendments only in the second production cycle. Higher yields of cowpea in T5 treatment, during the 2009/2010 cycle, are indicative that higher doses of gypsum and organic matter applied in this treatment accelerate the reclamation process. For other treatments with amendment application there was a beneficial effect for this crop only in the second cycle, when the values of productivity were similar to T5.

Carlos H. C. de, Sousa; Claudivan F. de, Lacerda; Francisco L. B. da, Silva; Antonia L. R., Neves; Raimundo N. T., Costa; Hans R., Gheyi.

2014-10-01

254

Performance testing rotating gamma camera SPECT systems  

International Nuclear Information System (INIS)

A reasonably simple protocol for testing the performance of rotating gamma camera SPECT systems has been established, which could be performed in about 10 hours. This protocol has been used to test almost all currently available systems, including GE, Siemens, Technicare, Elscint, Phillips, CGR, etc. In general, several models of a given system were tested in order to give an indication of the range of results that might be obtained. Reconstructions were performed in a standard manner (Uniformity correction, Ramp filter, no attenuation correction) in order to try to eliminate the effect of differences in software. In addition to using the Jaszczak phantom as an overall test pattern, measurements were made of spatial resolution, energy resolution, contrast, variations of sensitivity and uniformity with angle, etc. Results indicated that some systems, with a high resolution collimator and after very careful setting up, could achieve a spatial resolution of the order of 11mm, with good image quality. Not all commercially available systems performed as well. Strong indication was given of the need to improve spatial resolution, even at the expense of sensitivity, confirming the results from simulated tomographic data for various design compromises. Tests were also performed varying the energy window used. It was found that only very few system were capable of producing artefact free images with other than a symmetric photopeak window. However, very significant improvementdow. However, very significant improvement of image quality of current systems with respect to older systems were noted. This protocol has been used, in addition, to establish a routine quality assurance program for such SPECT systems

255

Integrated soil–crop system management for food security  

OpenAIRE

China and other rapidly developing economies face the dual challenge of substantially increasing yields of cereal grains while at the same time reducing the very substantial environmental impacts of intensive agriculture. We used a model-driven integrated soil–crop system management approach to develop a maize production system that achieved mean maize yields of 13.0 t ha?1 on 66 on-farm experimental plots—nearly twice the yield of current farmers’ practices—with no increase in N fe...

Chen, Xin-ping; Cui, Zhen-ling; Vitousek, Peter M.; Cassman, Kenneth G.; Matson, Pamela A.; Bai, Jin-shun; Meng, Qing-feng; Hou, Peng; Yue, Shan-chao; Ro?mheld, Volker; Zhang, Fu-suo

2011-01-01

256

Hyperspectral remote sensing analysis of short rotation woody crops grown with controlled nutrient and irrigation treatments.  

Energy Technology Data Exchange (ETDEWEB)

Abstract - Hyperspectral remote sensing research was conducted to document the biophysical and biochemical characteristics of controlled forest plots subjected to various nutrient and irrigation treatments. The experimental plots were located on the Savannah River Site near Aiken, SC. AISA hyperspectral imagery were analysed using three approaches, including: (1) normalized difference vegetation index based simple linear regression (NSLR), (2) partial least squares regression (PLSR) and (3) machine-learning regression trees (MLRT) to predict the biophysical and biochemical characteristics of the crops (leaf area index, stem biomass and five leaf nutrients concentrations). The calibration and cross-validation results were compared between the three techniques. The PLSR approach generally resulted in good predictive performance. The MLRT approach appeared to be a useful method to predict characteristics in a complex environment (i.e. many tree species and numerous fertilization and/or irrigation treatments) due to its powerful adaptability.

Im, Jungho; Jensen, John R.; Coleman, Mark; Nelson, Eric

2009-04-01

257

Nitrogen balance and groundwater nitrate contamination: Comparison among three intensive cropping systems on the North China Plain  

International Nuclear Information System (INIS)

The annual nitrogen (N) budget and groundwater nitrate-N concentrations were studied in the field in three major intensive cropping systems in Shandong province, north China. In the greenhouse vegetable systems the annual N inputs from fertilizers, manures and irrigation water were 1358, 1881 and 402 kg N ha-1 on average, representing 2.5, 37.5 and 83.8 times the corresponding values in wheat (Triticum aestivum L.)-maize (Zea mays L.) rotations and 2.1, 10.4 and 68.2 times the values in apple (Malus pumila Mill.) orchards. The N surplus values were 349, 3327 and 746 kg N ha-1, with residual soil nitrate-N after harvest amounting to 221-275, 1173 and 613 kg N ha-1 in the top 90 cm of the soil profile and 213-242, 1032 and 976 kg N ha-1 at 90-180 cm depth in wheat-maize, greenhouse vegetable and orchard systems, respectively. Nitrate leaching was evident in all three cropping systems and the groundwater in shallow wells (<15 m depth) was heavily contaminated in the greenhouse vegetable production area, where total N inputs were much higher than crop requirements and the excessive fertilizer N inputs were only about 40% of total N inputs. - Intensive greenhouse vegetable production systems may pose a greater nitrogen pollution threat than apple orchards or cereal rotations to soil and water quality in north China

258

Modeling greenhouse gas emissions in Chinese cropping systems using the DAYCENT model  

Science.gov (United States)

Ecosystem models are important tools to predict greenhouse gas (GHG) emissions for different climatic regions and management practices. In this study we integrated a methanogenesis sub-model into the DAYCENT ecosystem model to estimate CH4 emissions from rice production systems in China. The sub-model was parameterized using 25 sites, and then the DAYCENT model was evaluated with 353 sites in the croplands of China. Comparison of modeled results with observations for dryland crop systems demonstrated that yields, SOC changes, N2O emissions can be successfully simulated with the R2 of 0.87, 0.54 and 0.78, respectively. In paddy rice systems, the R2 were 0.81, 0.47, 0.74 and 0.83 for rice yields, SOC changes, N2O emissions and CH4 emissions, respectively. DAYCENT is reasonably accurate and precise in simulating GHG emissions for Chinese agricultural systems under various agricultural management practices, i.e. cropping rotations, water regimes, organic matter amendment and N fertilizer application rates. Field scale estimates of mitigation potential have been analyzed with DAYCENT, and this study provides the basis for further evaluation of mitigation potential and the impact of climate change with a regional application of DAYCENT in China's cropland. Geographical distribution of croplands in China that were used for evaluation of the DAYCENT model Statistics describing the performance of the DAYCENT model;

Cheng, K.; Ogle, S. M.; Parton, W. J.; Pan, G.

2012-12-01

259

Efeitos da rotação de culturas na incidência de podridões radiciais e na produtividade da soja / Effects of crop rotation on root rot incidence and on soybean grain yield  

Scientific Electronic Library Online (English)

Full Text Available Em experimentos conduzidos no campo, no sistema plantio direto, nas safras de verão de 2003/04, 2004/05 e 2005/06 foram avaliados os efeitos de culturas de inverno, da rotação e da monocultura sobre a emergência de plântulas, na incidência de podridões radiciais e no rendimento de grãos da soja. Dem [...] onstrou-se não haver efeitos das culturas de inverno sobre a emergência de plântulas da soja. Quanto à incidência de podridões radiciais em monocultura foi registrada uma intensidade de até 99,2%. O maior rendimento de grãos foi obtido na soja cultivada em rotação com uma safra com milho. Os fungos isolados do sistema radicial de plantas infectadas foram, Macrophomina phaseolina, Phomopsis sp., Fusarium spp. e Colletotrichum truncata. O solo da área experimental pode ser considerado supressivo aos fatores que reduzem a germinação, a emergência de plântulas e de morte de plântulas/plantas de soja. Quanto ao seu efeito em reduzir as podridões radiciais, ainda não se detectou efeito supressivo, porém a rotação da soja com o milho reduziu a incidência de podridões radiciais e aumentou o rendimento de grãos da soja. Abstract in english In experiments carried out in the field, under no-till planting system, in 2003/04, 2004/05 and 2005/06 summer growing seasons, the effects of winter crops, rotation and monoculture on seedling emergence, root rot incidence and soybean grain yield were assessed. There were no effects of winter crops [...] on soybean seedling emergence. As to root rot incidence on monoculture, an intensity of up to 99.2% was recorded. Grain yield was highest when soybean was cultivated in one season of rotation with corn. The fungi isolated from the root system of infected plants were Macrophomina phaseolina, Phomopsis sp., Fusarium spp. and Colletotrichum truncata. The soil at the experimental area can be considered suppressive to factors that reduce soybean germination, seedling emergence, and seedling/plant death. Considering its effect in reducing root rot, a suppressive action has not been detected yet; however, soybean rotation with corn reduced root rot incidence and increased soybean grain yield.

Erlei Melo, Reis; Marivane, Segalin; Nara Lucia, Moraes; Valeria Cecília, Ghissi.

2014-03-01

260

Eco-efficient approaches to land management: a case for increased integration of crop and animal production systems.  

Science.gov (United States)

Eco-efficiency is concerned with the efficient and sustainable use of resources in farm production and land management. It can be increased either by altering the management of individual crop and livestock enterprises or by altering the land-use system. This paper concentrates on the effects of crop sequence and rotation on soil fertility and nutrient use efficiency. The potential importance of mixed farming involving both crops and livestock is stressed, particularly when the systems incorporate biological nitrogen fixation and manure recycling. There is, however, little evidence that the trend in developed countries to farm-level specialization is being reduced. In some circumstances legislation to restrict diffuse pollution may provide incentives for more diverse eco-efficient farming and in other circumstances price premia for produce from eco-efficient systems, such as organic farming, and subsidies for the provision of environmental services may provide economic incentives for the adoption of such systems. However, change is likely to be most rapid where the present systems lead to obvious reductions in the productive potential of the land, such as in areas experiencing salinization. In other situations, there is promise that eco-efficiency could be increased on an area-wide basis by the establishment of linkages between farms of contrasting type, particularly between specialist crop and livestock farms, with contracts for the transfer of manures and, to a lesser extent, feeds. PMID:17652073

Wilkins, R J

2008-02-12

261

Spatial distribution of reniform nematode in cotton as influenced by soil texture and crop rotations.  

Science.gov (United States)

Reniform nematode (RN) is an important pest in cotton production. Knowledge of the distribution patterns of RN is essential for selecting sampling strategies and for site-specific management. A three-year study was conducted in two fields in South Carolina with the purpose of characterizing the distribution of RN using a fine-scale sampling scheme in plots representing different soil textures (field 1), and using a large-scale arbitrary sampling scheme (field 2). Horizontal distribution data showed an aggregated pattern of RN densities at planting and after harvest in both fields each year, with patches ranging from 8 to 12 m. However, a significant neighborhood structure was only detected when suitable hosts (cotton and soybean) were planted. Correlations between RN densities and percent sand and silt were detected, showing nematode densities peaked when sand content was around 60 % and declined when sand content increased above 60-65%. When fewer samples were taken in the field with more uniform sand content, % sand was a less reliable predictor of RN densities. Vertical sampling showed the highest numbers of RN were found at 15-30 cm deep after cotton, but were deeper after a non-host crop. Understanding distribution patterns of RN is essential for selecting sampling strategies and for delineating zones for site-specific management. PMID:25412010

Holguin, Claudia; Gerard, Patrick; Mueller, John D; Khalilian, Ahmad; Agudelo, Paula

2014-11-20

262

How short rotation forest crops can be used for sustainable remediation of contaminated areas  

Energy Technology Data Exchange (ETDEWEB)

In large territories of the CIS, it becomes obvious from the factual consequences of the Chernobyl environmental contamination that no successful remediation actions can be achieved without considering realistic technical and economical issues. In these conditions, the Short Rotation Forestry concept for energy purposes is proposed as an alternative and integrated approach for the recovery of agricultural practices on waste farm land. This corrective option will be examined with respect to this ecological, economical, and social relevancy. Different aspects of the culture in contaminated areas and of energy production from biomass remain to be investigated, developed and validated in the light of radiation protection criteria. In particular, attention will be drawn on the opportunity of this new concept to be integrated in the development of the site remediation research activities at SCK.CEN.

Thiry, I.

1996-09-18

263

Optimising harvesting and storage systems for energy crops in the Netherlands  

OpenAIRE

For perennial crops like short rotation coppice (in particular willow), rhizomatous grasses (like miscanthus, switch grass and reed canary grass) as well as the annual crop hemp all operations for harvesting and storage are discussed. These are mowing, size reduction, densification, conservation, storage and pre-treatment. The requirements for energy conversion and co-firing are given and the effect of harvest conditions or quality is shown. The best production chains for average conditions o...

Huisman, W.

2003-01-01

264

Environmental assessment of two different crop systems in terms of biomethane potential production.  

Science.gov (United States)

The interest in renewable energy sources has gained great importance in Europe due to the need to reduce fossil energy consumption and greenhouse gas emissions, as required by the Renewable Energy Directive (RED) of the European Parliament. The production of energy from energy crops appears to be consistent with RED. The environmental impact related to this kind of energy primarily originates from crop cultivation. This research aimed to evaluate the environmental impact of different crop systems for biomass production: single and double crop. The environmental performances of maize and maize plus wheat were assessed from a life cycle perspective. Two alternative scenarios considering different yields, crop management, and climatic conditions, were also addressed. One normal cubic metre of potential methane was chosen as a functional unit. Methane potential production data were obtained through lab experimental tests. For both of the crop systems, the factors that have the greatest influence on the overall environmental burden are: fertilizer emissions, diesel fuel emissions, diesel fuel production, and pesticide production. Notwithstanding the greater level of methane potential production, the double crop system appears to have the worse environmental performance with respect to its single crop counterpart. This result is due to the bigger quantity of inputs needed for the double crop system. Therefore, the greater amount of biomass (silage) obtained through the double crop system is less than proportional to the environmental burden that results from the bigger quantity of inputs requested for double crop. PMID:23994820

Bacenetti, Jacopo; Fusi, Alessandra; Negri, Marco; Guidetti, Riccardo; Fiala, Marco

2014-01-01

265

An Ultrasonic System for Weed Detection in Cereal Crops  

Directory of Open Access Journals (Sweden)

Full Text Available Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group discrimination were assessed by discriminant analysis. The ultrasonic readings permitted the separation between weed infested zones and non-infested areas with up to 92.8% of success. This system will potentially reduce the cost of weed detection and offers an opportunity to its use in non-selective methods for weed control.

Dionisio Andújar

2012-12-01

266

An ultrasonic system for weed detection in cereal crops.  

Science.gov (United States)

Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index) computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group discrimination were assessed by discriminant analysis. The ultrasonic readings permitted the separation between weed infested zones and non-infested areas with up to 92.8% of success. This system will potentially reduce the cost of weed detection and offers an opportunity to its use in non-selective methods for weed control. PMID:23443401

Andújar, Dionisio; Weis, Martin; Gerhards, Roland

2012-01-01

267

Wireless computer vision system for crop stress detection  

Science.gov (United States)

Knowledge of soil water deficits, crop water stress, and biotic stress from disease or insects is important for optimal irrigation scheduling and water management. Crop spectral reflectances provide a means to quantify visible and near infrared thermal crop stress, but in-situ measurements can be cu...

268

Short rotation coppice culture of willows and poplars as energy crops on metal contaminated agricultural soils.  

Science.gov (United States)

Phytoremediation, more precisely phytoextraction, has been placed forward as an environmental friendly remediation technique, that can gradually reduce increased soil metal concentrations, in particular the bioavailable fractions. The aim of this study was to investigate the possibilities of growing willows and poplars under short rotation coppice (SRC) on an acid, poor, sandy metal contaminated soil, to combine in this way soil remediation by phytoextraction on one hand, and production of biomass for energy purposes on the other. Above ground biomass productivities were low for poplars to moderate for willows, which was not surprising, taking into account the soil conditions that are not very favorable for growth of these trees. Calculated phytoextraction efficiency was much longer for poplars than these for willows. We calculated that for phytoextraction in this particular case it would take at least 36 years to reach the legal threshold values for cadmium, but in combination with production of feedstock for bioenergy processes, this type of land use can offer an alternative income for local farmers. Based on the data of the first growing cycle, for this particular case, SRC of willows should be recommended. PMID:22046760

Ruttens, Ann; Boulet, Jana; Weyens, Nele; Smeets, Karen; Adriaensen, Kristin; Meers, Erik; Van Slycken, Stijn; Tack, Filip; Meiresonne, Linda; Thewys, Theo; Witters, Nele; Carleer, Robert; Dupae, Joke; Vangronsveld, Jaco

2011-01-01

269

Convective Heat and Mass Transfer in Rotating Disk Systems  

CERN Document Server

The book describes results of investigations of a series of convective heat and mass transfer problems in rotating-disk systems, namely, over free rotating disks, under conditions of transient heat transfer, solid- body rotation of fluid, orthogonal flow impingement onto a disk, swirl radial flow between parallel co-rotating disks, in cone-disk systems and for Prandtl and Schmidt numbers larger than unity. Methodology used included integral methods, self-similar and approximate analytical solutions, as well as CFD. The book is aimed at the professional audience of academic researchers, industr

Shevchuk, Igor V

2009-01-01

270

Energy crops for biogas plants. Mecklenburg-Western Pomerania; Energiepflanzen fuer Biogasanlagen. Mecklenburg-Vorpommern  

Energy Technology Data Exchange (ETDEWEB)

For agriculturists in Mecklenburg-Western Pomerania (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

Aurbacher, J.; Bull, I.; Formowitz, B. (and others)

2012-06-15

271

Energy crops for biogas plants. Saxony-Anhalt; Energiepflanzen fuer Biogasanlagen. Sachsen-Anhalt  

Energy Technology Data Exchange (ETDEWEB)

For agriculturists in Saxony-Anhalt (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

Boese, L.; Buttlar, C. von; Boettcher, K. (and others)

2012-07-15

272

Arbuscular Mycorrhizal Fungal Associations in Biofuel Cropping Systems  

Science.gov (United States)

Arbuscular mycorrhizal fungi (AMF) are soil microorganisms that play an important role in delivering nutrients to plant roots via mutualistic symbiotic relationships. AMF root colonization was compared between four different biofuel cropping systems in an effort to learn more about the factors that control colonization. The four biofuel systems sampled were corn, switchgrass, prairie, and fertilized prairie. We hypothesized that prairie systems would have the highest levels of AMF colonization and that fertilization would result in lower AMF colonization rates. Roots were sampled from each system in early June and mid-July. Soil P and pH were also measured. In contrast to our hypothesis, corn systems had 70-80% colonization and the unfertilized prairie system had ~35% (P=0.001) in June. In July, all systems saw an increase in colonization rate, but corn roots still had significantly more AMF colonization than unfertilized prairie (P=0.001). AMF colonization in the unfertilized prairie system increased ~55% from June to July. In contrast to previous work, AMF colonization rates were highest in systems with the greatest availability on P and N (corn systems). These results indicate that seasonal differences in root growth were more influential to AMF root colonization than soil nutrient availability.

Murray, K.

2012-12-01

273

Soil carbon after three years under short rotation woody crops grown under varying nutrient and water availability  

Energy Technology Data Exchange (ETDEWEB)

Soil carbon contents were measured on a short-rotation woody crop study located on the US Department of Energy's Savannah River Site outside Aiken, SC. This study included fertilization and irrigation treatments on five tree genotypes (sweetgum, loblolly pine, sycamore and two eastern cottonwood clones). Prior to study installation, the previous pine stand was harvested and the remaining slash and stumps were pulverized and incorporated 30 cm into the soil. One year after harvest soil carbon levels were consistent with pre-harvest levels but dropped in the third year below pre-harvest levels. Tillage increased soil carbon contents, after three years, as compared with adjacent plots that were not part of the study but where harvested, but not tilled, at the same time. When the soil response to the individual treatments for each genotype was examined, one cottonwood clone (ST66), when irrigated and fertilized, had higher total soil carbon and mineral associated carbon in the upper 30 cm compared with the other tree genotypes. This suggests that root development in ST66 may have been stimulated by the irrigation plus fertilization treatment.

Sanchez, Felipe G. [USDA Forest Service; Coleman, Mark [USDA Forest Service; Garten Jr, Charles T [ORNL; Luxmoore, Robert J [ORNL; Stanturf, J. A. [USDA Forest Service; Trettin, Carl [USDA Forest Service; Wullschleger, Stan D [ORNL

2007-01-01

274

Soil carbon, after 3 years, under short-rotation woody crops grown under varying nutrient and water availability  

Energy Technology Data Exchange (ETDEWEB)

Soil carbon contents were measured on a short-rotation woody crop study located on the US Department of Energy's Savannah River Site outside Aiken, SC. This study included fertilization and irrigation treatments on five tree genotypes (sweetgum, loblolly pine, sycamore and two eastern cottonwood clones). Prior to study installation, the previous pine stand was harvested and the remaining slash and stumps were pulverized and incorporated 30 cm into the soil. One year after harvest soil carbon levels were consistent with pre-harvest levels but dropped in the third year below pre-harvest levels. Tillage increased soil carbon contents, after three years, as compared with adjacent plots that were not part of the study but where harvested, but not tilled, at the same time. When the soil response to the individual treatments for each genotype was examined, one cottonwood clone (ST66), when irrigated and fertilized, had higher total soil carbon and mineral associated carbon in the upper 30 cm compared with the other tree genotypes. This suggests that root development in ST66 may have been stimulated by the irrigation plus fertilization treatment. (author)

Sanchez, Felipe G. [USDA Forest Service, Southern Research Station, Forestry Sciences Laboratory, 3041 Cornwallis Road, Research Triangle Park, NC 27709 (United States); Coleman, Mark [USDA Forest Service, Southern Research Station, Savannah River Institute, P.O. Box 700, New Ellenton, SC 29809 (United States); Garten, Charles T. Jr.; Luxmoore, Robert J.; Wullschleger, Stan D. [Environmenal Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 38731 (United States); Stanturf, John A. [USDA Forest Service, Southern Research Station, Forestry Sciences Laboratory, 320 Green Street, Athens, GA 30602 (United States); Trettin, Carl [USDA Forest Service, Southern Research Station, Center for Forested Wetlands Research, 2730 Savannah Highway, Charleston, SC 29414 (United States)

2007-11-15

275

Plant nutrient and water balance studies under legume-cereal rotation systems  

International Nuclear Information System (INIS)

A two-year cycle of crop rotation experiments with at least three main treatments of cereal-cereal, legume-cereal and fallow-cereal treatments was outlined. The water balance approach was utilized to estimate crop water consumption and to compare different crop rotation systems, in view of water conservation and of increasing efficient use of scarcely available water under rainfed areas of Middle-Eastern Countries, with low and erratic rainfall characteristics. The use of the neutron scattering technique was recommended for easy monitoring of changes in soil water storage, as one of the key field data required in the water balance equation. The use of 15N-labelled fertilizers provided a unique tool allowing to separately study the behaviour of N-fertilizer as well as soil N. In addition, the quantification of residual fertilizer N was possible. Also, the use of labelled N allowed to quantify the amount of biologically fixed N2. (author). 7 refs, 4 figs, 1 tab

276

Automatic expert system based on images for accuracy crop row detection in maize fields  

OpenAIRE

This paper proposes an automatic expert system for accuracy crop row detection in maize fields based on images acquired from a vision system. Different applications in maize, particularly those based on site specific treatments, require the identification of the crop rows. The vision system is designed with a defined geometry and installed onboard a mobile agricultural vehicle, i.e. submitted to vibrations, gyros or uncontrolled movements. Crop rows can be estimated by applying geometrical pa...

Guerrero, Josep M.; Guijarro Mata-garci?a, Mari?a; Montalvo Marti?nez, Marti?n; Romeo Granados, Juan; Emmi, Luis Alfredo; Ribeiro Seijas, Angela; Pajares Martinsanz, Gonzalo

2013-01-01

277

Increasing Crop Diversity Mitigates Weather Variations and Improves Yield Stability  

Science.gov (United States)

Cropping sequence diversification provides a systems approach to reduce yield variations and improve resilience to multiple environmental stresses. Yield advantages of more diverse crop rotations and their synergistic effects with reduced tillage are well documented, but few studies have quantified the impact of these management practices on yields and their stability when soil moisture is limiting or in excess. Using yield and weather data obtained from a 31-year long term rotation and tillage trial in Ontario, we tested whether crop rotation diversity is associated with greater yield stability when abnormal weather conditions occur. We used parametric and non-parametric approaches to quantify the impact of rotation diversity (monocrop, 2-crops, 3-crops without or with one or two legume cover crops) and tillage (conventional or reduced tillage) on yield probabilities and the benefits of crop diversity under different soil moisture and temperature scenarios. Although the magnitude of rotation benefits varied with crops, weather patterns and tillage, yield stability significantly increased when corn and soybean were integrated into more diverse rotations. Introducing small grains into short corn-soybean rotation was enough to provide substantial benefits on long-term soybean yields and their stability while the effects on corn were mostly associated with the temporal niche provided by small grains for underseeded red clover or alfalfa. Crop diversification strategies increased the probability of harnessing favorable growing conditions while decreasing the risk of crop failure. In hot and dry years, diversification of corn-soybean rotations and reduced tillage increased yield by 7% and 22% for corn and soybean respectively. Given the additional advantages associated with cropping system diversification, such a strategy provides a more comprehensive approach to lowering yield variability and improving the resilience of cropping systems to multiple environmental stresses. This could help to sustain future yield levels in challenging production environments. PMID:25658914

Gaudin, Amélie C. M.; Tolhurst, Tor N.; Ker, Alan P.; Janovicek, Ken; Tortora, Cristina; Martin, Ralph C.; Deen, William

2015-01-01

278

Increasing crop diversity mitigates weather variations and improves yield stability.  

Science.gov (United States)

Cropping sequence diversification provides a systems approach to reduce yield variations and improve resilience to multiple environmental stresses. Yield advantages of more diverse crop rotations and their synergistic effects with reduced tillage are well documented, but few studies have quantified the impact of these management practices on yields and their stability when soil moisture is limiting or in excess. Using yield and weather data obtained from a 31-year long term rotation and tillage trial in Ontario, we tested whether crop rotation diversity is associated with greater yield stability when abnormal weather conditions occur. We used parametric and non-parametric approaches to quantify the impact of rotation diversity (monocrop, 2-crops, 3-crops without or with one or two legume cover crops) and tillage (conventional or reduced tillage) on yield probabilities and the benefits of crop diversity under different soil moisture and temperature scenarios. Although the magnitude of rotation benefits varied with crops, weather patterns and tillage, yield stability significantly increased when corn and soybean were integrated into more diverse rotations. Introducing small grains into short corn-soybean rotation was enough to provide substantial benefits on long-term soybean yields and their stability while the effects on corn were mostly associated with the temporal niche provided by small grains for underseeded red clover or alfalfa. Crop diversification strategies increased the probability of harnessing favorable growing conditions while decreasing the risk of crop failure. In hot and dry years, diversification of corn-soybean rotations and reduced tillage increased yield by 7% and 22% for corn and soybean respectively. Given the additional advantages associated with cropping system diversification, such a strategy provides a more comprehensive approach to lowering yield variability and improving the resilience of cropping systems to multiple environmental stresses. This could help to sustain future yield levels in challenging production environments. PMID:25658914

Gaudin, Amélie C M; Tolhurst, Tor N; Ker, Alan P; Janovicek, Ken; Tortora, Cristina; Martin, Ralph C; Deen, William

2015-01-01

279

Nitrogen dynamics and balance in a lowland rice cropping system  

International Nuclear Information System (INIS)

Two field experiments were conducted during consecutive dry and wet seasons of 1997 in central Thailand to determine the effects of rice-residue management on the fate and use efficiency of urea-N broadcast to lowland rice (70 kg N ha-1). Ammonia (NH3) losses during the 11 days following urea application were 7, 12, and 8% of the applied N from no-residue, burned-residue, and residue-treated plots, respectively, whereas the cumulative percentage of N2+N2O emission from added urea corresponded to 10, 4.3, and nil, respectively. During the first crop, only about 9% of the fertilizer N applied was recovered in grain and straw. Appreciable N fertilizer was either lost from the soil-plant system (27-33%) or remained in the soil at the end of the growing season (50- 53%). Residual fertilizer-N recovery in the second crop was only about 5% of what was initially applied. (author)

280

Fertilization regimes affect the soil biological characteristics of a sudangrass and ryegrass rotation system.  

Science.gov (United States)

The sudangrass (Sorghum sudanense) and ryegrass (Lolium multiflorum L.) rotation is an intensive and new cropping system in Central China. Nutrient management practices in this rotation system may influence soil fertility, the important aspects of which are soil biological properties and quality. As sensitive soil biological properties and quality indicators, soil microbial community activity, microbial biomass, enzyme activities, soil organic matter (SOM) and total N resulting from different fertilization regimes in this rotation system were studied through a four-year field experiment from April 2005 to May 2009. Treatments included control (CK), fertilizer phosphorus and potassium (PK), fertilizer nitrogen and potassium (NK), fertilizer nitrogen and phosphorus (NP) and a fertilizer nitrogen, phosphorus and potassium combination (NPK). Soil microbial community activities in the NK, NP and NPK treatments were significantly lower than those in the CK and PK treatments after the sudangrass and ryegrass trial. The highest microbial biomass C, microbial biomass N, SOM, total N, sucrase and urease activities were found in the NPK treatment, and these soil quality indicators were significantly higher in the NK, NP and NPK treatments than in the PK and CK treatments. Soil microbial biomass and enzyme activities were positively associated with SOM in the sudangrass and ryegrass rotation system, indicating that fertilization regimes, especially N application, reduced microbial community activity in the soil. Proper fertilization regimes will increase microbial biomass, enzyme activity and SOM and improve soil fertility. PMID:21706419

Li, WenXi; Lu, JianWei; Li, FangBai; Wang, Yan; Lu, JunMing; Li, XiaoKun

2011-06-01

281

Generating a Crop Rotation Dataset for the U.S and its Application in Inferring Land Use Change Induced Wetland Losses in the Prairie Pothole Region  

Science.gov (United States)

Agricultural management practices plays a major role in the global fluxes of greenhouse gases, soil carbon sequestration and production of ecosystem services. A key component of these practices are the crop rotations selected by the farmer. Here, we present an algorithm to create a crop rotation dataset for the U.S and demonstrate the tradeoffs between the number and accuracy of rotations comprising a state. To generate the rotations, we use the USDA Cropland Data Layer (CDL) available for the entire U.S at a resolution of 30 m from 2010 to 2012. Several studies have generated rotations simply by merging several years of CDL data, resulting in thousands of rotations per state. Alternatively, they tend to aggregate the rotations into a few predefined categories. This over simplification can lead to erroneous acreage values impacting both biogeochemical model estimates and land use change studies. Our algorithm uses the edit distance metric to combine similar rotations to obtain a product which retains the accuracy of CDL while minimizing the number of rotations. We find that 180 unique rotations are needed to represent the entire U.S with an accuracy exceeding 80% when compared to the underlying CDL datasets for rotations from 2010 to 2012. For the agriculturally important and diverse Western corn belt, the number of rotations needed to represent each state with an accuracy exceeding 90% when compared to the CDL dataset, ranges from 3 unique rotations for Iowa to more than 50 for North Dakota. As an application of the dataset, we examine the findings of Wright and Wimberly (1), who reported in a recent issue of PNAS that recent grassland conversion to corn and soybean cropping (GRCS) from 2006 to 2011 in the Prairie Pothole Region (PPR) is concentrated in the vicinity of wetlands. Their analysis implicitly assumes that all wetlands affected by GRCS in the PPR existed in or after 2006. However, the areal extent of wetlands was based on National Wetland Inventory maps, which were produced from aerial photography taken in the 1970s and 1980s. Thus, we conclude that Wright and Wimberly overestimated the total area of agricultural expansion through GRCS within 500 m of wetlands. Instead of attributing historical wetland conversion to recent land use changes in the PPR, here we provide separate estimates of wetland conversion from 1982 - 2007 and 2006 - 2011 using data from National Resources Inventory and rotations generated using CDL data from 2006 to 2011. We use the rotations generated using CDL data from 2006 to 2011, to estimate the total area of agricultural expansion through GRCS within 500 m of wetlands in the PPR. We find that the total grassland acreage in close proximity to wetlands that was converted to corn/soybean cropping between 2006 and 2011 was 58% of the nearly 400,000 ha estimated by Wright and Wimberly. While biofuel production impacts land use decisions, it is critical to use appropriate tools and datasets to inform our analysis of environmental impacts of these decisions, lest it divert our focus from other drivers of land use change. Reference: 1. Wright CK, Wimberly MC (2013) Recent land use change in the Western Corn Belt threatens grasslands and wetlands. PNAS.

Sahajpal, R.; Zhang, X.; Izaurralde, R. C.; Hurtt, G. C.

2013-12-01

282

An overview of crop growing condition monitoring in China agriculture remote sensing monitoring system  

Science.gov (United States)

China is a large agricultural country. To understand the agricultural production condition timely and accurately is related to government decision-making, agricultural production management and the general public concern. China Agriculture Remote Sensing Monitoring System (CHARMS) can monitor crop acreage changes, crop growing condition, agriculture disaster (drought, floods, frost damage, pest etc.) and predict crop yield etc. quickly and timely. The basic principles, methods and regular operation of crop growing condition monitoring in CHARMS are introduced in detail in the paper. CHARMS can monitor crop growing condition of wheat, corn, cotton, soybean and paddy rice with MODIS data. An improved NDVI difference model was used in crop growing condition monitoring in CHARMS. Firstly, MODIS data of every day were received and processed, and the max NDVI values of every fifteen days of main crop were generated, then, in order to assessment a certain crop growing condition in certain period (every fifteen days, mostly), the system compare the remote sensing index data (NDVI) of a certain period with the data of the period in the history (last five year, mostly), the difference between NDVI can indicate the spatial difference of crop growing condition at a certain period. Moreover, Meteorological data of temperature, precipitation and sunshine etc. as well as the field investigation data of 200 network counties were used to modify the models parameters. Last, crop growing condition was assessment at four different scales of counties, provinces, main producing areas and nation and spatial distribution maps of crop growing condition were also created.

Huang, Qing; Zhou, Qing-bo; Zhang, Li

2009-07-01

283

Soil Fungal Resources in Annual Cropping Systems and Their Potential for Management  

Science.gov (United States)

Soil fungi are a critical component of agroecosystems and provide ecological services that impact the production of food and bioproducts. Effective management of fungal resources is essential to optimize the productivity and sustainability of agricultural ecosystems. In this review, we (i) highlight the functional groups of fungi that play key roles in agricultural ecosystems, (ii) examine the influence of agronomic practices on these fungi, and (iii) propose ways to improve the management and contribution of soil fungi to annual cropping systems. Many of these key soil fungal organisms (i.e., arbuscular mycorrhizal fungi and fungal root endophytes) interact directly with plants and are determinants of the efficiency of agroecosystems. In turn, plants largely control rhizosphere fungi through the production of carbon and energy rich compounds and of bioactive phytochemicals, making them a powerful tool for the management of soil fungal diversity in agriculture. The use of crop rotations and selection of optimal plant genotypes can be used to improve soil biodiversity and promote beneficial soil fungi. In addition, other agronomic practices (e.g., no-till, microbial inoculants, and biochemical amendments) can be used to enhance the effect of beneficial fungi and increase the health and productivity of cultivated soils. PMID:25247177

Esmaeili Taheri, Ahmad; Bainard, Luke D.; Yang, Chao; Navarro-Borrell, Adriana; Hamel, Chantal

2014-01-01

284

Thermodynamics in rotating systems -- analysis of selected examples  

CERN Document Server

We solve a set of selected exercises on rotational motion requiring a mechanical and thermodynamical analysis. When non-conservative forces or thermal effects are present, a complete study must use the first law of thermodynamics together with the Newton's second law. The latter is here better expressed in terms of an `angular' impulse-momentum equation (Poinsot-Euler equation), or, equivalently, in terms of a `rotational' pseudo-work-energy equation. Thermodynamical aspects in rotational systems, when e.g. frictional forces are present or when there is a variation of the rotational kinetic energy due to internal sources of energy, are discussed.

Güémez, Julio

2014-01-01

285

Thermodynamics in rotating systems—analysis of selected examples  

Science.gov (United States)

We solve a set of selected exercises on rotational motion requiring a mechanical and thermodynamical analysis. When non-conservative forces or thermal effects are present, a complete study must use the first law of thermodynamics together with Newton’s second law. The latter is here better expressed in terms of an ‘angular’ impulse-momentum equation (Poinsot-Euler equation), or, equivalently, in terms of a ‘rotational’ pseudo-work-energy equation. Thermodynamical aspects in rotational systems, when e.g. frictional forces are present or when there is a variation of the rotational kinetic energy due to internal sources of energy, are discussed.

Güémez, J.; Fiolhais, M.

2014-01-01

286

Thermodynamics in rotating systems—analysis of selected examples  

International Nuclear Information System (INIS)

We solve a set of selected exercises on rotational motion requiring a mechanical and thermodynamical analysis. When non-conservative forces or thermal effects are present, a complete study must use the first law of thermodynamics together with Newton’s second law. The latter is here better expressed in terms of an ‘angular’ impulse–momentum equation (Poinsot–Euler equation), or, equivalently, in terms of a ‘rotational’ pseudo-work–energy equation. Thermodynamical aspects in rotational systems, when e.g. frictional forces are present or when there is a variation of the rotational kinetic energy due to internal sources of energy, are discussed. (paper)

287

Stability of a pulsating rotating model of a stellar system  

International Nuclear Information System (INIS)

Stability of pulsating rotating model of a stellar system is under discussion. Evaluation of the effect of chaotic motion and rotation on the stability with respect to the transition to ellipsoidis given using as an example the two-parametric nonstationary model of the Freeman sphere

288

Phase considerations in a rotating system  

International Nuclear Information System (INIS)

A neutron interferometer in constant absolute rotation will exhibit a certain phase-shift between its two beams, a phenomenon shared with the classic Sagnac or Michelson-Gale-Pearson experiments or with the modern laser-gyrocompass composed of lasers in a ring. To first order in the rotational frequency, it is possible to understand by employing only rudimentary theory, the essence of this phenomenon to any degree of relativistiness of the participating particle. This paper is mainly paedagogical, noting the similarity due to permanent rotation between photon-, electron and neutron-interferometers. Future experimentation, aside from corroborating well believed tenets, may hope with improving precision to bring new approaches to measurement of fundamental effects

289

Adaptation of the European crop growth monitoring system to the Belgian conditions.  

OpenAIRE

The aim of the Belgian Crop Growth Monitoring System (B-CGMS) is the elaboration of an integrated information system predicting reliable, timely and objective estimates of crop yields and monitoring calamity sites at regional scales. Seven major crops are concerned by the project : winter wheat, winter barley, fodder maize, winter rape seed, potatoes, sugar beet and permanent meadow. The main tasks in the adaptation of the European model come down to the completion and the improvement of the ...

Buffet, D.; Dehem, Didier; Wouters, K.; Tychon, Bernard; Oger, Robert; Veroustraete, F.

1999-01-01

290

Classification of the field drainage and wetness by using aerial photographs in irrigated paddy rice and upland crop rotation field  

Science.gov (United States)

Information about field drainage/wetness is useful for farmers to plan field management in irrigated paddy rice and upland crop rotation field. Wet injury is a loss to farmers in upland crop farming, experience is the most common way of approaching this risk. In this study, we propose to provide efficient and objective classify and mapping method of such field drainage information using aerial photography. Study area (500 ha) is located in Ibaraki Prefecture, Japan. In this area, we acquired multitemporalaerial photographs (ADS40) three times after the rain on winter. Digital Number (DN) of Blue, Green, Red and Near Infrared band were used to analyze. To analyze the relationship between each band DN and soil moisture, mass soil water content of 0-5cm depth was determined using the 100ml core sample at 22 sites on shooting date. And to verify our classification of the drainage and wetness, volumetric soil water content was monitored using TDR sensor (Decagon, ECH2O) at 5cm, 10cm and 20 cm depth at 16 sites. First, optimum band was selected from correlation analysis of mass soil water content and DN. Next, optimum band DN of three aerial photographs at field area was grouped by cluster analysis (ISODATA method). We found a good positive correlation between mass soil water content and red band DN, by selecting optimum bands. 17 groups were found from cluster analysis using three aerial photographs with different soil moisture conditions. After that, we classified them into five levels of field drainage based on red band DN values. We generated maps of drainage/wetness based on these results. We compared volumetric soil water content at the monitoring site for the "Dry" and "Wet" points, water was drained quickly at the "Dry" site but it needed more than 1 week the volume soil water content back to revert before rain at the "Wet" site. By the result, we positively verified our classification. We used three aerial photographs with different soil moisture conditions as proxy of top soil moisture content. It is thought to be an indication of drainage/wetness. Generally, estimating soil water content at field scale from a remote sensing data was difficult. But this method can classify the study area relatively. We think it is enough as a soil information for farmers.

Ritsuko, Fuchiyama; Takeshi, Ota; Michikazu, Fukuhara

2013-04-01

291

Sustainable cropping systems using cover crops, native species field borders and riparian buffers for environmental quality  

Science.gov (United States)

This presentation will focus on the application of sustainable management practices for no-till cultivation using cover crops, native species field borders, and fast growing woody species integrated in vegetative strips and riparian buffers. An ongoing field project at the Bradford Research and Exte...

292

Crop rotation biomass and arbuscular mycorrhizal fungi effects on sugarcane yield Produção de biomassa e presença de fungos micorrízicos arbusculares em culturas utilizadas em rotação com a cana-de-açúcar  

Directory of Open Access Journals (Sweden)

Full Text Available A cana-de-açúcar (Saccharum spp. vem sendo cultivada no Brasil para produção de açúcar e agroenergia. Em seu sistema de produção, após um ciclo de 4 a 8 anos, é possível a rotação com plantas de cobertura, antes do seu replantio, para melhoria do solo e geração de renda. Estudou-se a caracterização e produtividade de biomassa de leguminosas (como adubos-verdes e girassol (Helianthus annuus L., a ocorrência natural de micorrizas, o teor de açúcar e a produtividade em colmos da cana-de-açúcar IAC 87-3396 e a viabilidade econômica desse sistema com cultivo após as opções de rotação, com quantificação da produtividade durante três cortes consecutivos. O amendoim (Arachis hypogaea L. cv. IAC-Caiapó, girassol cv. IAC-Uruguai e mucuna-preta (Mucuna aterrimum Piper and Tracy foram as culturas que apresentaram maior percentagem de colonização por fungos micorrízicos. O girassol foi a planta de cobertura que mais extraiu nutrientes do solo, seguido por amendoim (Arachis hipogaea L. cv. IAC-Tatu e feijão-mungo (Vigna radiata L. Wilczek. A colonização por fungos micorrízicos mostrou correlação positiva com a altura de plantas de cana no primeiro corte (p = 0,01 e R = 0,52, mas não se correlacionou com a produtividade de colmos ou açúcar. No primeiro corte, o girassol foi a cultura de rotação que ocasionou o maior aumento de produtividade, da ordem de 46% em colmos e de 50% na quantidade de açúcar, em comparação com a testemunha. Com exceção dos amendoins, todas as culturas em rotação aumentaram a renda líquida do sistema na média de três cortes de cana-de-açúcar.Sugarcane (Saccharum spp. is an important crop for sugar production and agro-energy purposes in Brazil. In the sugarcane production system after a 4- to 8-year cycle crop rotation may be used before replanting sugarcane to improve soil conditions and give an extra income. This study had the objective of characterizing the biomass and the natural colonization of arbuscular mycorrhizal fungi (AMF of leguminous green manure and sunflower (Helianthus annuus L. in rotation with sugarcane. Their effect on stalk and sugar yield of sugarcane cv. IAC 87-3396 grown subsequently was also studied. Cane yield was harvested in three subsequent cuttings. Peanut cv. IAC-Caiapó, sunflower cv. IAC-Uruguai and velvet bean (Mucuna aterrimum Piper and Tracy were the rotational crops that resulted in the greater percentage of AMF. Sunflower was the specie that most extracted nutrients from the soil, followed by peanut cv. IAC-Tatu and mung bean (Vigna radiata L. Wilczek. The colonization with AMF had a positive correlation with sugarcane plant height, at the first cut (p = 0.01 and R = 0.52 but not with the stalk or cane yields. Sunflower was the rotational crop that brought about the greatest yield increase of the subsequent sugarcane crop: 46% increase in stalk yield and 50% in sugar yield compared with the control. Except for both peanut varieties, all rotational crops caused an increase in net income of the cropping system in the average of three sugarcane harvests.

Edmilson José Ambrosano

2010-12-01

293

Dissolved Organic Carbon and Nitrogen in Andisol for Six Crop Rotations with Different Soil Management Intensity Carbono y Nitrógeno Orgánicos Disueltos en un Andisol Sometido a Seis Rotaciones de Cultivos con Diferente Intensidad en el Manejo del Suelo  

OpenAIRE

Soil organic matter (OM) content is a quality indicator, but is an inadequate indicator in the short-term because these changes take place slowly, so dissolved organic components have emerged as an alternative. In volcanic soil subjected to different crop rotations with distinct land use intensity, dissolved organic C and N (DOC and DON) were determined as well as their relationship with total C and N contents in the soil, considering the effects of crop rotation, fertilization level, and soi...

Pablo Undurraga D; Erick Zagal V; Gloria Sepúlveda W; Natalia Valderrama V

2009-01-01

294

Behavior of Atrazine In Limited Irrigation Cropping Systems in Colorado: Prior Use Is Important  

Science.gov (United States)

The Irrigation Water Optimization Project was begun in 2005 at Colorado State University to develop cropping systems to optimize use of limited irrigation water supply while sustaining production. Corn is a major component of many of these cropping systems and atrazine is used to provide residual w...

295

CROPPING SYSTEMS ALTER WEED SEED BANK IN PACIFIC NORTHWEST, USA SEMI-ARID WHEAT REGION  

Science.gov (United States)

Weed management is an important consideration in implementing new cropping systems. Grower interest in no-till spring cropping systems is increasing in the semi-arid region of the Pacific Northwest because of wind erosion from winter wheat (Triticum aestivum L.)/tillage fallow (WWF). However, no-t...

296

Life cycle assessment of various cropping systems utilized for producing biofuels: Bioethanol and biodiesel  

International Nuclear Information System (INIS)

A life cycle assessment of different cropping systems emphasizing corn and soybean production was performed, assuming that biomass from the cropping systems is utilized for producing biofuels (i.e., ethanol and biodiesel). The functional unit is defined as 1 ha of arable land producing biomass for biofuels to compare the environmental performance of the different cropping systems. The external functions are allocated by introducing alternative product systems (the system expansion allocation approach). Nonrenewable energy consumption, global warming impact, acidification and eutrophication are considered as potential environmental impacts and estimated by characterization factors given by the United States Environmental Protection Agency (EPA-TRACI). The benefits of corn stover removal are (1) lower nitrogen related environmental burdens from the soil, (2) higher ethanol production rate per unit arable land, and (3) energy recovery from lignin-rich fermentation residues, while the disadvantages of corn stover removal are a lower accumulation rate of soil organic carbon and higher fuel consumption in harvesting corn stover. Planting winter cover crops can compensate for some disadvantages (i.e., soil organic carbon levels and soil erosion) of removing corn stover. Cover crops also permit more corn stover to be harvested. Thus, utilization of corn stover and winter cover crops can improve the eco-efficiency of the cropping systems. When biomass from the cropping systemsms. When biomass from the cropping systems is utilized for biofuel production, all the cropping systems studied here offer environmental benefits in terms of nonrenewable energy consumption and global warming impact. Therefore utilizing biomass for biofuels would save nonrenewable energy, and reduce greenhouse gases. However, unless additional measures such as planting cover crops were taken, utilization of biomass for biofuels would also tend to increase acidification and eutrophication, primarily because large nitrogen (and phosphorus)-related environmental burdens are released from the soil during cultivation

297

Rotating fluidized bed hydrogen production system  

Energy Technology Data Exchange (ETDEWEB)

A three stage hydrogen generator (10), comprises a low btu, carbon monoxide and hydrogen containing gas generation stage, a first reactor stage (12) for exothermically reducing ferric oxide with the low btu gas and for generating superheated steam and a second reactor stage (14) for endothermically reacting steam and iron to produce substantially pure hydrogen gas. The hydrogen gas together with unreacted steam from the third stage (16) is directed to a condenser (18), preferably an air cooled unit, wherein the steam is condensed and the hydrogen gas recovered. The condensate (20) is cycled back to the second reactor (14) as the feed water for generating superheated steam and the heated cooling air (22) is directed to the first stage (12) for use in the generation of the low btu gas. At least one, and preferably all, of the stages utilize a rotating fluidized bed. Desirably the condenser (18) is a rotating fluidized bed heat exchanger.

Belke, W.H.; Grim, G.B.

1982-08-10

298

ROMADIS - A rotating machinery diagnosis system  

International Nuclear Information System (INIS)

This paper describes the PC-based software package ROMADIS developed for the rotating machinery diagnosis. It contains advanced signal processing techniques for extracting multi-features from the time records and uses a modified decision tree technique for the knowledge acquisition, the knowledge representation and the failure diagnosis process. It is user-friendly programmed and the diagnostic results are very easy to be verified. (author). 5 refs, 3 figs

299

A gravitational torque energy harvesting system for rotational motion  

OpenAIRE

This thesis describes a novel, single point-of-attachment, gravitational torque energy harvesting system powered from rotational motion. The primary aim of such a system is to scavenge energy from a continuously rotating host in order to power a wireless sensor node. In this thesis, a wireless tachometer was prototyped. Most published work on motion-driven energy harvesters has used ambient vibrations in the environment as the energy source. However, none of the reported device...

Toh, Tzern Tzuin

2011-01-01

300

A WEB BASED TOMATO CROP EXPERT INFORMATION SYSTEM BASED ON ARTIFICIAL INTELLIGENCE AND MACHINE LEARNING ALGORITHMS  

Directory of Open Access Journals (Sweden)

Full Text Available Tomato is now the most widely grown vegetable crop in World. It is grown throughout the world in farm gardens, small home-gardens, and by market gardeners for fresh consumption as well as for processingpurposes. This Tomato crop expert advisory system is aimed at a collaborative venture with eminent Agriculture Scientist and Experts in the area of Tomato Plantation with an excellent team of computer Engineers, programmers and designers. This Expert System contains two main parts one is Tomato Information System and the other is Tomato Crop Expert System where in Information system, the user can get all the static information about different species, Diseases,Symptoms, chemical controls, Preventions, Pests, Virus of Tomato fruits and plants. In Advisory System, the user is having aninteraction with the expert system online; the user has to answer the questions asked by the Expert System. Depends on the response by the user the expert system decides the disease and displays its control measure of disease. This Tomato Crop Information Expert System deals with different varieties of Tomato Crop, Identification of various diseases generally occurs to tomato crop based on the symptoms.This Rule based Expert System validates the symptoms of the tomato crop using the techniques of ID3 Algorithm and some optimization algorithms. This is a Web based Expert System with java as the front end and SQL as the backend.

Prasad Babu M.S

2010-03-01

301

Multi-Attribute Modelling of Economic and Ecological Impacts of Cropping Systems  

OpenAIRE

Modelling of economic and ecological impacts of genetically modified crops is a demanding task. We present some preliminary attempts made for the purpose of the ECOGEN project "Soil ecological and economic evaluation of genetically modified crops". One of the goals of the project is to develop a computer-based decision support system for the assessment of economic and ecological impacts of using genetically modified crops, with special emphasis on soil biology and ecology. The decision suppor...

Bohanec, M.; Dzeroski, S.; Znidarsic, M.; Messe?an, A.; Scatasta, S.; Wesseler, J. H. H.

2004-01-01

302

TropGENE-DB, a multi-tropical crop information system  

OpenAIRE

TropGENE-DB, is a crop information system created to store genetic, molecular and phenotypic data of the numerous yet poorly documented tropical crop species. The most common data stored in TropGENE-DB are information on genetic resources (agro-morphological data, parentages, allelic diversity), molecular markers, genetic maps, results of quantitative trait loci analyses, data from physical mapping, sequences, genes, as well as the corresponding references. TropGENE-DB is organized on a crop ...

Ruiz, Manuel; Rouard, Mathieu; Raboin, Louis Marie; Lartaud, Marc; Lagoda, Pierre; Courtois, Brigitte

2004-01-01

303

Use of isotope techniques in evaluation of fertilizer management practices for cropping systems  

International Nuclear Information System (INIS)

The methods by which isotopic techniques have been used in sole cropping studies are reviewed, and the application of those techniques to complex cropping systems is discussed. Strip intercropping, sequential cropping, and relay, row, and mixed intercropping are shown to present many complexities which isotopes could play an important role in clarifying. The depth, spread and activity of rooting systems can be studied with P-32 or P-33, and double labelling may be very informative in defining the interpenitration or changes in rooting pattern resulting from intercropping. Nitrification inhibitors with N-15 labelled fertilizer may be useful in restricting fertilizer N to the non-fixing component of row or mixed intercropping systems. Similarly, P-32, N-15 and S-35 labelled fertilizers may be useful for fertilizer placement studies. Where legumes are included in the cropping systems N-15 abundance techniques can be used to estimate the contribution of N biologically fixed by the legume to the entire cropping system. (author)

304

Tile drain losses of nitrogen and phosphorus from fields under integrated and organic crop rotations. A four-year study on a clay soil in southwest Sweden.  

Science.gov (United States)

In order to explore the influence of site-specific soil properties on nitrogen (N) and phosphorus (P) losses between individual fields and crop sequences, 16 drained fields with clay soils were investigated in a four-year study. Mean total N (TN) loss was 6.6-11.1 from a conventional, 14.3-21.5 from an organic and 13.1-23.9 kg ha(-1) year(-1) from an integrated cropping system across a 4 year period, with 75% in nitrate form (NO(3)-N). Mean total P (TP) loss was 0.96-3.03, 0.99-4.63 and 0.76-2.67 kg ha(-1) year(-1), from the three systems respectively during the same period, with 25% in dissolved reactive form (DRP). Median N efficiency was calculated to be 70% including gains from estimated N fixation. According to principal component factor (PCA) analysis, field characteristics and cropping system were generally more important for losses of N and P than year. Accumulation of soil mineral N in the autumn and (estimated) N fixation was important for N leaching. No P fertilisers were used at the site in either cropping system. Total P concentration in drainage water from each of the fields was marginally significantly (pcrop with efficient nutrient uptake and good soil structure was general preconditions for low nutrient leaching. Incorporation of ley by tillage operations in the summer before autumn crop establishment and repeated operations in autumn as well, increased N leaching. Crop management in sequences with leguminous crops needs to be considered carefully when designing cropping systems high efficiency in N utilisation and low environmental impact. PMID:22264921

Stenberg, Maria; Ulén, Barbro; Söderström, Mats; Roland, Björn; Delin, Karl; Helander, Carl-Anders

2012-09-15

305

Crop residues as raw materials for biorefinery systems - A LCA case study  

International Nuclear Information System (INIS)

Our strong dependence on fossil fuels results from the intensive use and consumption of petroleum derivatives which, combined with diminishing oil resources, causes environmental and political concerns. The utilization of agricultural residues as raw materials in a biorefinery is a promising alternative to fossil resources for production of energy carriers and chemicals, thus mitigating climate change and enhancing energy security. This paper focuses on a biorefinery concept which produces bioethanol, bioenergy and biochemicals from two types of agricultural residues, corn stover and wheat straw. These biorefinery systems are investigated using a Life Cycle Assessment (LCA) approach, which takes into account all the input and output flows occurring along the production chain. This approach can be applied to almost all the other patterns that convert lignocellulosic residues into bioenergy and biochemicals. The analysis elaborates on land use change aspects, i.e. the effects of crop residue removal (like decrease in grain yields, change in soil N2O emissions and decrease of soil organic carbon). The biorefinery systems are compared with the respective fossil reference systems producing the same amount of products/services from fossils instead of biomass. Since climate change mitigation and energy security are the two most important driving forces for biorefinery development, the assessment focuses on greenhouse gas (GHG) emissions and cumulative primary enerGHG) emissions and cumulative primary energy demand, but other environmental categories are evaluated as well. Results show that the use of crop residues in a biorefinery saves GHG emissions and reduces fossil energy demand. For instance, GHG emissions are reduced by about 50% and more than 80% of non-renewable energy is saved. Land use change effects have a strong influence in the final GHG balance (about 50%), and their uncertainty is discussed in a sensitivity analysis. Concerning the investigation of the other impact categories, biorefinery systems have higher eutrophication potential than fossil reference systems. Based on these results, a residues-based biorefinery concept is able to solve two problems at the same time, namely find a use for the abundant lignocellulosic residues and ensure a mitigation effect for most of the environmental concerns related to the utilization of non-renewable energy resources. Therefore, when agricultural residues are used as feedstocks, best management practices and harvest rates need to be carefully established. In fact, rotation, tillage, fertilization management, soil properties and climate can play an important role in the determination of the amount of crop residue that can be removed minimizing soil carbon losses.

306

Magnetic nanofluids and magnetic composite fluids in rotating seal systems  

Science.gov (United States)

Recent results are presented concerning the development of magnetofluidic leakage-free rotating seals for vacuum and high pressure gases, evidencing significant advantages compared to mechanical seals. The micro-pilot scale production of various types of magnetizable sealing fluids is shortly reviewed, in particular the main steps of the chemical synthesis of magnetic nanofluids and magnetic composite fluids with light hydrocarbon, mineral oil and synthetic oil carrier liquids. The behavior of different types of magnetizable fluids in the rotating sealing systems is analyzed. Design concepts, some constructive details and testing procedures of magnetofluidic rotating seals are presented such as the testing equipment. The main characteristics of several magnetofluidic sealing systems and their applications will be presented: vacuum deposition systems and liquefied gas pumps applications, mechanical and magnetic nanofluid combined seals, gas valves up to 40 bar equipped by rotating seal with magnetic nanofluids and magnetic composite fluids.

Borbáth, T.; Bica, D.; Potencz, I.; Vékás, L.; Borbáth, I.; Boros, T.

2010-08-01

307

Magnetic nanofluids and magnetic composite fluids in rotating seal systems  

Energy Technology Data Exchange (ETDEWEB)

Recent results are presented concerning the development of magnetofluidic leakage-free rotating seals for vacuum and high pressure gases, evidencing significant advantages compared to mechanical seals. The micro-pilot scale production of various types of magnetizable sealing fluids is shortly reviewed, in particular the main steps of the chemical synthesis of magnetic nanofluids and magnetic composite fluids with light hydrocarbon, mineral oil and synthetic oil carrier liquids. The behavior of different types of magnetizable fluids in the rotating sealing systems is analyzed. Design concepts, some constructive details and testing procedures of magnetofluidic rotating seals are presented such as the testing equipment. The main characteristics of several magnetofluidic sealing systems and their applications will be presented: vacuum deposition systems and liquefied gas pumps applications, mechanical and magnetic nanofluid combined seals, gas valves up to 40 bar equipped by rotating seal with magnetic nanofluids and magnetic composite fluids.

Borbath, T; Borbath, I; Boros, T [Roseal Corporation, Nicolae Balcescu street, no. 5/A, Odorheiu Secuiesc, 535600 (Romania); Bica, D; Vekas, L [Lab. Magnetic Fluids, Center for Fundamental and Advanced Technical Research, Romanian Academy, Timisoara Division (LMF-CFATR-RATD) Mihai Viteazul Bvd., no. 24, Timisoara, 300223 (Romania); Potencz, I, E-mail: office@roseal.topnet.r [National Center for Engineering of Systems with Complex Fluids, University Politehnica Timisoara, Mihai Viteazul Bvd., no. 1, Timisoara, 300222 (Romania)

2010-08-15

308

Magnetic nanofluids and magnetic composite fluids in rotating seal systems  

International Nuclear Information System (INIS)

Recent results are presented concerning the development of magnetofluidic leakage-free rotating seals for vacuum and high pressure gases, evidencing significant advantages compared to mechanical seals. The micro-pilot scale production of various types of magnetizable sealing fluids is shortly reviewed, in particular the main steps of the chemical synthesis of magnetic nanofluids and magnetic composite fluids with light hydrocarbon, mineral oil and synthetic oil carrier liquids. The behavior of different types of magnetizable fluids in the rotating sealing systems is analyzed. Design concepts, some constructive details and testing procedures of magnetofluidic rotating seals are presented such as the testing equipment. The main characteristics of several magnetofluidic sealing systems and their applications will be presented: vacuum deposition systems and liquefied gas pumps applications, mechanical and magnetic nanofluid combined seals, gas valves up to 40 bar equipped by rotating seal with magnetic nanofluids and magnetic composite fluids.

309

Seeding Rate and Planting Arrangement Effects on a Legume-Oat Cover Crop in Organic Vegetable Systems  

Science.gov (United States)

Winter cover crops are integral components in rotations on high-value, organic vegetable farms in the central coast of California, and can provide benefits such as reducing nitrate leaching, suppressing weeds, and adding soil organic matter. Legume-cereal mixed cover crops may also reduce reliance o...

310

Influence of Cropping System Intensity on Dry Matter Yield and Nitrogen Concentration in Different Parts of Soybean Plant  

Directory of Open Access Journals (Sweden)

Full Text Available Two-year investigations were conducted within the three-year maize-soybean-wheat crop rotation with the aim to assess the influence of two cropping systems, conditionally marked as high-input and reduced-input systems, on soybean dry matter yield and nitrogen concentration in its different plant parts. The high-input system was characterized by: ploughing at 30-32 cm, fertilization with 80 kg N and 130 P2O5 and K2O kg ha-1, weed control based on oxasulfuron and, if required, a corrective treatment with propachizafop and bentazone. The reduced-input system involved: ploughing at 20-22 cm, fertilization with a total of 40 kg N and 130 kg P2O5 and K2O kg ha-1, and only oxasulfuron-based weed control. Investigations involved two soybean genotypes: L 940596 and L 910631, vegetation group I. An identical monofactorial trial with four replications was set up in each cropping system. Cropping system intensity had a positive effect on leaf and stem dry matter mass in 2002, and on leaf and stem nitrogen concentration, whereas it had no effect on pod dry matter, seed yield and seed nitrogen concentrations in either year. The highest leaf dry matter was recorded in R4 development stage and that of stem and pod without seeds in R7 development stage. In both trial years, the highest nitrogen concentrations in leaf and stem were recorded in R1 development stage. In both trial years, higher pod nitrogen concentration was achieved in R4 development stage than in the R7 stage.

Klaudija Carovi?

2006-10-01

311

In situ denitrification rates in shallow groundwater beneath a spring barley - mustard cover crop system  

Science.gov (United States)

Mustard catch crop has been reported to increase dissolved organic carbon (DOC) concentrations in groundwater, which can be used as an energy source for denitrifiers. This study investigates the impact of a mustard catch crop on in situ denitrification and nitrous oxide (N2O) emissions from an aquifer overlain by arable land. Denitrification rates and N2O-N/(N2O-N+N2-N) mole fractions were measured in situ with a push-pull method in shallow groundwater under a spring barley system in experimental plots with an without a mustard cover crop. The results suggest that a mustard cover crop could substantially enhance reduction of groundwater nitrate (NO3--N) via denitrification without significantly increasing N2O emissions. Mean total denitrification (TDN) rates below mustard cover crop and no cover crop were 7.61 and 0.002 µg kg-1 d-1, respectively. Estimated N2O-N/(N2O-N+N2-N) ratios, being 0.001 and 1.0 below mustard cover crop and no cover crop respectively, indicate that denitrification below mustard cover crop reduces N2O to N2, unlike the plot with no cover crop. The observed enhanced denitrification under the mustard cover crop may result from the higher groundwater DOC under mustard cover crop (1.53 mg L-1) than no cover crop (0.90 mg L-1) being added by the root exudates and root masses of mustard. This study gives insights into the missing piece in agricultural nitrogen (N) balance and groundwater derived N2O emissions under arable land.

Mofizur Rahman Jahangir, Mohammad; Minet, Eddy; Johnston, Paul; Coxon, Catherine; Richards, Karl

2014-05-01

312

Icing research tunnel rotating bar calibration measurement system  

Science.gov (United States)

In order to measure icing patterns across a test section of the Icing Research Tunnel, an automated rotating bar measurement system was developed at the NASA Lewis Research Center. In comparison with the previously used manual measurement system, this system provides a number of improvements: increased accuracy and repeatability, increased number of data points, reduced tunnel operating time, and improved documentation. The automated system uses a linear variable differential transformer (LVDT) to measure ice accretion. This instrument is driven along the bar by means of an intelligent stepper motor which also controls data recording. This paper describes the rotating bar calibration measurement system.

Gibson, Theresa L.; Dearmon, John M.

1993-03-01

313

Rotação e sucessão de culturas para o manejo do nematoide reniforme em área de produção de soja / Crop rotation and crop sequences for the management of the reniform nematode in area of soybean production  

Scientific Electronic Library Online (English)

Full Text Available O nematoide reniforme (Rotylenchulus reniformis) tem se tornado crescente problema fitossanitário da cultura da soja. Considerando a limitada disponibilidade de cultivares de soja que aliem resistência ao nematoide a outras características agronômicas desejáveis, estuda-se a possibilidade de utiliza [...] ção de manejo cultural para seu controle. Este trabalho visou avaliar o efeito da rotação de culturas no verão com milho, Crotalaria ochroleuca ou soja; e o manejo de entressafra, com Brachiaria ruziziensis como espécie de cobertura ou pousio. O experimento foi implantado em solo naturalmente infestado pelo nematoide reniforme (1245 nematoides/200cc de solo) em delineamento experimental de blocos ao acaso, com quatro repetições, em esquema fatorial 3x2 (cultivos de verão x manejo de entressafra). Foram avaliadas a densidade populacional do nematoide no solo e sua variação durante as safras e entressafras, bem como a produtividade da soja na safra subsequente à rotação de culturas. Não houve efeito do manejo da entressafra com braquiária sobre o nematoide. A rotação de culturas com milho ou crotalária no verão propiciou redução da densidade populacional do nematoide reniforme em comparação ao monocultivo de soja, com reflexos positivos sobre a produtividade de soja na safra seguinte Abstract in english The reniform nematode (Rotylenchulus reniformis) has become a growing disease problem to soybean crop. Considering the limited availability of soybean varieties that combine resistance to the nematode and other desirable agronomic traits, cultural management could be an approach for the nematode man [...] agement. This study aimed to evaluate the effect of summer season crop rotations with corn or sunnhemp compared with soybean monocropping, and fall management with ruzizigrass as a covercrop compared to fallow on the nematode population. The experiment was carried-out in a naturally infested soil (1245 reniform nematodes/200cc soil) in a randomized block design, with six treatments arranged in plots with 6x3m (18m2) with four replications in a factorial 3x2 (summer crop x fall management). The nematode soil population density and its variation during the season as well as the soybean yield in the subsequent soybean crop were evaluated. Crop rotation with corn or sunnhemp led to the decrease on the reniform nematode population density compared to the monoculture of soybeans, with positive effects on soybean yield in the following season. There was no effect of cover cropping with ruzizigrass on the reniform nematode population

Hugo Márcio, Leandro; Guilherme Lafourcade, Asmus.

314

Effect of Tillage Practices on Soil Properties and Crop Productivity in Wheat-Mungbean-Rice Cropping System under Subtropical Climatic Conditions  

OpenAIRE

This study was conducted to know cropping cycles required to improve OM status in soil and to investigate the effects of medium-term tillage practices on soil properties and crop yields in Grey Terrace soil of Bangladesh under wheat-mungbean-T. aman cropping system. Four different tillage practices, namely, zero tillage (ZT), minimum tillage (MT), conventional tillage (CT), and deep tillage (DT), were studied in a randomized complete block (RCB) design with four replications. Tillage practice...

Md. Khairul Alam; Md. Monirul Islam; Nazmus Salahin; Mirza Hasanuzzaman

2014-01-01

315

Impact of sole cropping and multiple cropping on soil humified carbon fractions  

International Nuclear Information System (INIS)

The present study was planned to improve our understanding how crop rotation can enhance humified C fractions. A long term experiment was conducted on Vanmeter farm of the Ohio State University South Centers at Piketon Ohio, USA from 2002 to 2007. Crop rotation treatments included were continuous corn (CC), corn-soybean (CS) and corn-soybean-wheat-cowpea (CSW) rotations. Randomized complete block design with 6 replications was used under natural field conditions. The findings of this long-term study revealed that multiple cropping had significantly improved humified carbon fractions compared to mono-cropping system. Although total humified carbon (THOC), sugar free humified carbon (HOC) concentration were non-significant however, humin (NH) contents, humic (HA), fulvic acids (FA), humic and fulvic acid associated glucose (HA-NH and FA-NH) were significantly affected by various crop rotations within five years. The soil under CC had 22-52% significantly greater NH concentration than CSW and CS rotations respectively. Similarly all crop rotations had shown 5-16 increase in HA and 5-17% decreased in FA over time. Likewise soil under CC had 16 and 54% greater HA-NH concentration as compared to CSW and CS rotations. The FA-NH concentration increased significantly by 27- 51% in soil under all treatments over time. The soil under CSW had greater HA/FA (1.6) fallowed by CC (1.4) and CS (1.1). Soils under CSW had significantly greater HA/HOC (12-18%) as compare to CC and CS respectively. Conversely, the value of FA/HOC decreased (1-23%) in soil under all crop rotation treatments within five years. Degree of humification (DH) had shown a significant increase (7-12%) in soil under all treatments as compared to 2002. Irrespective of crop rotation THOC, HOC, NH, humin, HA, HR and FA/HOC concentration decreased significantly with increase in soil depth. While fulvic acid concentration HA/HOC in all crop rotation increased with increase in soil depth. The effect of crop rotation on humified C fractions could be because of variations in type, amount and quality of C returned by different plants into the soil. So replacing mono-cropping with multiple cropping can enhance humified C fractions and can improve soil functional properties. (author)

316

Rotational and librational motion of solar system bodies  

Science.gov (United States)

Planetary exploration has revealed the great richness and diversity of the terrestrial planets and natural satellites. The mean rotational motion of planets was determined from ground-based telescopes since few centuries and nowadays the measurement resolution afforded by space telescopes and spacecraft allows the detection of small variations in the rotational motion that bear the signature of internal properties. The investigation of the interiors of planets and satellites is instrumental to understanding planetary processes operating on a global scale. Here, we will present the knowledge of the rotation and librations (for bodies in spin-orbit resonance) of some Solar system bodies that has been measured recently.

Rambaux, N.

2014-12-01

317

Integrating livestock manure with a corn-soybean bioenergy cropping system improves short-term carbon sequestration rates and net global warming potential  

International Nuclear Information System (INIS)

Carbon cycling and the global warming potential (GWP) of bioenergy cropping systems with complete biomass removal are of agronomic and environmental concern. Corn growers who plan to remove corn stover as a feedstock for the emerging cellulosic ethanol industry will benefit from carbon amendments such as manure and compost, to replace carbon removed with the corn stover. The objective of this research was to determine the effect of beef cattle feedlot manure and composted dairy manure on short-term carbon sequestration rates and net global warming potential (GWP) in a corn-soybean rotation with complete corn-stover removal. Field experiments consisting of a corn-soybean rotation with whole-plant corn harvest, were conducted near East Lansing, MI over a three-year period beginning in 2002. Compost and manure amendments raised soil carbon (C) at a level sufficient to overcome the C debt associated with manure production, manure collection and storage, land application, and post-application field emissions. The net GWP in carbon dioxide equivalents for the manure and compost amended cropping systems was -934 and -784 g m-2 y-1, respectively, compared to 52 g m-2 y-1 for the non-manure amended synthetic fertilizer check. This work further substantiates the environmental benefits associated with renewable fuels and demonstrates that with proper management, the integration of livestock manures in biofuel cropping systems can enhanures in biofuel cropping systems can enhance greenhouse gas (GHG) remediation. (author)

318

Interacting galaxies: co-rotating and counter-rotating systems with tidal tails  

CERN Document Server

We analyse interacting galaxy pairs with evidence of tidal features in the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7). The pairs were selected within $z<0.1$ by requiring a projected separation $r_p < 50 \\kpc$ and relative radial velocity $\\Delta V < 500 \\kms$. We complete spectroscopic pairs using galaxies with photometric redshifts considering $\\Delta V_{phot} < 6800 \\kms$, taking into account the mean photometric redshift uncertainty. We classify by visual inspection pairs of spirals into co-rotating and counter-rotating systems. For a subsample of non-AGN galaxies, counter-rotating pairs have larger star formation rates, and a higher fraction of young, star-forming galaxies. These effects are enhanced by restricting to $r_p < 12 \\kpc$. The distributions of $C$, $D_n(4000)$ and $(M_u-M_r)$ for AGN galaxies show that counter-rotating hosts have bluer colours and younger stellar population than the co-rotating galaxies although the relative fractions of Seyfert, Liner, Composite and Am...

Mesa, Valeria; Alonso, Sol; Coldwell, Georgina; Lambas, Diego G

2013-01-01

319

Dynamical friction in rotating systems - application to clusters and galaxies  

International Nuclear Information System (INIS)

The evolution due to dynamical friction in a rotating isothermal system is studied, and while the changes in the density profile were found to be marginal, the rotational velocity was seen to increase, with rotation curves flattening with time. It is suggested that if dynamic friction is significant in clusters of galaxies, brighter galaxies should have different rotational properties from the less massive ones. The M/L ratio was shown to remain constant as long as the value of central mass remains within the limits that are observed for clusters. It is also found that when the heavy objects subsystem and the main system are not corotating, no significant spinning up or slowing down of the heavy objects subsystem occurs. M(r = 0) is shown to depend on lambda, indicating that if galactic nuclei form from the decay of globular clusters, elliptical galaxies should have more massive nuclei than spiral ones. 34 references

320

REVIEW ON THE COIN RECOGNITION SYSTEM WITH ROTATION INVARIANT?  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a reliable coin recognition system that is based on a polar harmonic transform. Coins are widely used in daily routine at various places like in banks, automated weighing machines, supermarkets, organizations for research purposes. So, there is a basic need to recognize the coin very accurately. There is problem that if coin is rotated at some angle then the system is unable to recognize it so we are going to introduce a new approach for rotation invariant for coin recognition that is if coin image is rotated at some angle it can be recognized and will prove rotation invariant. So, this paper focuses on removing the need of placing coin in particular position by using artificial neural network.

Sandeep Kaur

2014-09-01

321

NET GLOBAL WARMING POTENTIAL AND GREENHOUSE GAS INTENSITY IN IRRIGATED CROPPING SYSTEMS IN NORTHEASTERN COLORADO  

Science.gov (United States)

The impact of management on global warming potential (GWP), crop production, and greenhouse gas intensity (GHGI) in irrigated agriculture is not well documented. A no-till (NT) cropping systems study initiated in 1999 to evaluate soil organic C (SOC) sequestration potential in irrigated agriculture...

322

Grazing winter rye cover crop in a cotton no-till system: yield and economics  

Science.gov (United States)

Winter cover crop adoption in conservation management systems continues to be limited in the US but could be encouraged if establishment costs could be offset. A 4-yr field experiment was conducted near Watkinsville, Georgia in which a rye (Secale cereale L.) cover crop was either grazed by catt...

323

Potential to develop crops to contribute to food security conservation, and sustainable systems  

Science.gov (United States)

As estimated, agricultural productivity needs to be increased by 70 percent or more by 2050 in order to meet the world’s food demand as global population increases. In the last few decades, improving agronomic traits in crops and efficiency in crop system management are two of the key components tha...

324

The Myth of Coexistence: Why Transgenic Crops Are Not Compatible With Agroecologically Based Systems of Production  

Science.gov (United States)

The coexistence of genetically modified (GM) crops and non-GM crops is a myth because the movement of transgenes beyond their intended destinations is a certainty, and this leads to genetic contamination of organic farms and other systems. It is unlikely that transgenes can be retracted once they have escaped, thus the damage to the purity of…

Altieri, Miguel

2005-01-01

325

Development test procedure for the ground demonstration system rotating seals  

Energy Technology Data Exchange (ETDEWEB)

This test procedure provides a detailed description of the verification methods which shall be used in the development program to be conducted on the Dynamic Isotope Power System (DIPS) rotating seals of the Combined Rotating Unit (CRU) assembly to fulfill the requirements of the Ground Demonstration System design criteria. The test ojectives are to characterize seal performance so that data can be used for seal configuration selection and system performance evaluation during Ground Demonstration System (GDS) testing. The various configurations that will be tested and their test parameters are shown.

1979-03-01

326

Development test procedure for the ground demonstration system rotating seals  

International Nuclear Information System (INIS)

This test procedure provides a detailed description of the verification methods which shall be used in the development program to be conducted on the Dynamic Isotope Power System (DIPS) rotating seals of the Combined Rotating Unit (CRU) assembly to fulfill the requirements of the Ground Demonstration System design criteria. The test ojectives are to characterize seal performance so that data can be used for seal configuration selection and system performance evaluation during Ground Demonstration System (GDS) testing. The various configurations that will be tested and their test parameters are shown

327

Cryogenic cooling with cryocooler on a rotating system  

OpenAIRE

We developed a system that continuously maintains a cryocooler for long periods on a rotating table. A cryostat that holds the cryocooler is set on the table. A compressor is located on the ground and supplies high-purity (> 99.999%) and high-pressure (1.7 MPa) helium gas and electricity to the cryocooler. The operation of the cryocooler and other instruments requires the development of interface components between the ground and rotating table. A combination of access holes...

Oguri, Shugo; Choi, Jihoon; Kawai, Masanori; Tajima, Osamu

2013-01-01

328

An Assessment of some Fertilizer Recommendations under Different Cropping Systems in a Humid Tropical Environment  

OpenAIRE

Studies were carried out to determine the effects of four fertilizer recommendation systems (bianket recommendation, soil test recommendation, recommendation based on nutrient supplementation index and unfertilized control) on five cropping systems (sole cassava, maize, melon, cassava + maize and cassava + maize + melon). The experiment was a split-plot in randomised complete block design, with fertilizer recommendation systems in main plots and cropping systems in subplots. Observations were...

Fondufe, Ey; Eneji, Ae; Agboola, Aa; Yamamoto, S.; Honna, T.

2001-01-01

329

Economics of wheat based cropping systems in rainfed areas of pakistan  

International Nuclear Information System (INIS)

The Pothwar tract of rainfed area has enormous potential to meet incremental food grain needs of the country. However, a significant yield gap in wheat has been reported between yields of substantive and the progressive growers mainly due to poor management of soil, water and fertility issues. A field study was conducted at National Agricultural Research Centre (NARC), Islamabad and the traditional wheat-fallow-wheat (W-F-W) cropping system was evaluated with the improved wheat-maize fodder-wheat (W-MF-W) and wheat-mungbean-wheat (W-MB-W) cropping systems. Two tillage practices, i.e. shallow tillage with cultivator and deep tillage with moldboard; and four fertilizer treatments viz., control (C), recommended dose of fertilizer for each crop (F), farmyard manure (FYM) at the rate -15 tha . The recommended doses of fertilizer for individual crop with FYM (F+FYM) were also included in the study to know their impact on the crops yield in the cropping systems. Economic analysis of the data revealed that the traditional wheat-fallow-wheat cropping system could be economically replaced with wheat-maize fodder-wheat cropping system even under drought condition and there will be no economical loss of wheat yield when planted after maize fodder. Application of recommended dose of fertilizer -1 along with FYM at the rate 5 tha will enhance the yield of wheat and maize fodder. The improved cropping system of wheat-maize fodder-wheat will help the farmers to sustain productivity ohelp the farmers to sustain productivity of these crops, stable economic benefits and improvement in soil nutrients and organic matter over time. (author)

330

Comparison of Soil Respiration in Typical Conventional and New Alternative Cereal Cropping Systems on the North China Plain  

Science.gov (United States)

We monitored soil respiration (Rs), soil temperature (T) and volumetric water content (VWC%) over four years in one typical conventional and four alternative cropping systems to understand Rs in different cropping systems with their respective management practices and environmental conditions. The control was conventional double-cropping system (winter wheat and summer maize in one year - Con.W/M). Four alternative cropping systems were designed with optimum water and N management, i.e. optimized winter wheat and summer maize (Opt.W/M), three harvests every two years (first year, winter wheat and summer maize or soybean; second year, fallow then spring maize - W/M-M and W/S-M), and single spring maize per year (M). Our results show that Rs responded mainly to the seasonal variation in T but was also greatly affected by straw return, root growth and soil moisture changes under different cropping systems. The mean seasonal CO2 emissions in Con.W/M were 16.8 and 15.1 Mg CO2 ha?1 for summer maize and winter wheat, respectively, without straw return. They increased significantly by 26 and 35% in Opt.W/M, respectively, with straw return. Under the new alternative cropping systems with straw return, W/M-M showed similar Rs to Opt.W/M, but total CO2 emissions of W/S-M decreased sharply relative to Opt.W/M when soybean was planted to replace summer maize. Total CO2 emissions expressed as the complete rotation cycles of W/S-M, Con.W/M and M treatments were not significantly different. Seasonal CO2 emissions were significantly correlated with the sum of carbon inputs of straw return from the previous season and the aboveground biomass in the current season, which explained 60% of seasonal CO2 emissions. T and VWC% explained up to 65% of Rs using the exponential-power and double exponential models, and the impacts of tillage and straw return must therefore be considered for accurate modeling of Rs in this geographical region. PMID:24278340

Gao, Bing; Ju, Xiaotang; Su, Fang; Gao, Fengbin; Cao, Qingsen; Oenema, Oene; Christie, Peter; Chen, Xinping; Zhang, Fusuo

2013-01-01

331

Analysis and modelling of rotational systems with the Modyfit application  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: of this article is to present an application to analysis and modelling of rotational systems. Independent modules of application enables controlling and regulation of characteristics of systems in transportation. The base problem of analyzing systems in transportation is expressing the interaction between the main motion and local vibrations of subsystems.Design/methodology/approach: Mathematical models derived in previous articles were used to implement the mathematical models in numerical calculations. The objectives of creating the Modyfit application were connected with analyzing and modelling rotating systems with taking into account relations between major and local motions. Considerations were done by the Galerkin’s method.Findings: There are many effects of analyzing systems with rotation consideration. Main of them are connected with analyzing systems in function of increasing the value of angular velocity. In such way of analyzing we can observe creating additional poles in the dynamical characteristics and we can also observe that instead of modes there are created zeros.Research limitations/implications: Analyzed systems are simple linear homogeneous beams and rods. Working motion is limited to plane motion. Future research would consider complex systems, damping and nonlinearity.Practical implications: of the application are numerical analysis of beams and rods in rotational transportation and designing such systems. Thank to the Modyfit we can derived the stability zones of analyzed beams and rods and we can observe eigenfrequencies and zeros in function of angular velocity.Originality/value: The Modyfit is a forerunner implementation of derived models in a numerical environment of dynamical flexibility. Analyzing models are rotating flexible systems with consideration the rotational transportation effect.

S. ?ó?kiewski

2008-09-01

332

Exact treatment of interacting bosons in rotating systems and lattices  

DEFF Research Database (Denmark)

Quantum systems of ultra-cold particles constitute a unique tool for studying the fundamental phenomena of physics in their purest and most isolated forms. Complicated dynamics are found even for few particles and to comprehend the features of systems with many particles, we must first understand these basic building blocks. In this dissertation we investigate few-particle behavior in rotating traps and optical lattices. These systems are both experimentally realizable and are used on a daily basis in quantum gas laboratories all over the world. At temperatures near absolute zero the quantum mechanical nature of particles dominate, resulting in a behavior fundamentally different from that of classical particles. In rotating systems this causes quantization of angular momentum which can lead to macroscopic vortices in rotating Bose-Einstein condensates. In optical lattices the atom becomes extended over several lattice points causing complicated many-body dynamics and phase transitions.

SØrensen, Ole SØe

2012-01-01

333

Estrategias de fertilización fosforada en una rotación de cultivos en el sudeste bonaerense Phosphorus fertilization strategies in a Buenos Aires southeast crop rotation  

Directory of Open Access Journals (Sweden)

Full Text Available En suelos del sudeste Bonaerense el fósforo (P del fertilizante forma productos de mediana a alta solubilidad, lo cual le confiere un alto valor residual. A partir de esto, surge la posibilidad de definir estrategias de fertilización basadas en la frecuencia con que se efectúa su aplicación. Para rotaciones de cuatro cultivos en tres años se desconoce el efecto de alternativas de fertilización fosfatada. Los objetivos fueron: 1 evaluar el rendimiento de cultivos fertilizados con P anualmente y cada tres años, a la rotación de cultivos, y 2 determinar la eficiencia de uso y de recuperación del P (EUP y ERP, respectivamente aplicado para dichas estrategias de fertilización. El experimento se realizó sobre un complejo de Paleudol Petrocálcico y Argiudol Típico en la EEA I.N.T.A. Balcarce, con un alto nivel inicial de P-Bray (28,7 mg kg-1 y bajo siembra directa. A lo largo de dos ciclos de rotación, integrados por maíz, soja y trigo/soja de segunda, se evaluaron tres tratamientos: aplicación de P con frecuencia anual, por única vez a la rotación y un testigo sin P, en bloques completos aleatorizados con cuatro repeticiones. No se observaron diferencias en el rendimiento de los cultivos fertilizados en forma anual y a la rotación, durante los dos ciclos. El testigo difirió de los tratamientos fertilizados solo durante el segundo ciclo de rotación. La EUP de la rotación (EUProt no difirió entre estrategias de aplicación (19,4 y 32,4 kg kg-1 durante el primer ciclo y 32,9 y 37,4 kg kg-1 durante el segundo, para tratamientos fertilizados anualmente y a la rotación, respectivamente. Tampoco existieron diferencias entre estrategias de fertilización en la EUP de cada cultivo. En cambio, durante el primer ciclo, la ERP resultó mayor para el tratamiento fertilizado a la rotación respecto de la aplicación anual (0,13 y 0,03 kg kg-1, mientras que en el segundo ciclo no se detectaron diferencias entre ambos (0,16 y 0,17 kg kg-1 para la aplicación anual y a la rotación, respectivamente. Se encontró una débil asociación entre la variación anual en el nivel de P-Bray y el balance de P correspondiente al cultivo implantado dicho año. Para el tratamiento testigo, se elaboró un modelo para predecir la disminución en el P disponible considerando el nivel inicial de P-Bray y la exportación de P de los cultivos como variables.In the soils of southeast Buenos Aires, fertilizer phosphorus (P forms medium to high solubility products, making it possible to define different fertilization strategies based on application frequency. The effect of P application rates capable of fulfilling all crop requirements in intensive rotations in the region is unknown. The objectives of this work were to: (1 assess yields in crops fertilized with P annually and once during the crop rotation and (2 determine P use efficiency and P recovery for each fertilization strategy. The experiment was conducted at the E.E.A. I.N.T.A. Balcarce on a Typic Argiudoll and Petrocalcic Paleudoll complex, under no-tillage and with high P-Bray (Bray & Kurts, 1945 content (28.7 mg kg-1. During the two rotation cycles for maize, soybean, and double wheat/soybean crop, three treatments were assessed: application of P annually, application once during the rotation cycle, and a control without P application. The experimental design was in randomized blocks with four repetitions. No crop yield differences were found between annual and rotation fertilization strategies across the two cycles evaluated. The control crop yield did not differ from the fertilized crop during the first rotation cycle but did during the second. The crop rotation P use efficiency (EUProt did not differ between nutrient applications strategies (19.4 and 32.4 kg kg-1 during the first cycle and 32.9 and 37.4 kg kg-1 during the second for annually and rotation fertilized treatments respectively. There were no differences between strategies in the crop P use efficiency of each crop (EUPcult. In contrast, during the first cycle, the applied P recovery efficiency (E

Guillermo Adrián Divito

2010-07-01

334

Improving wheat simulation capabilities in Australia from a cropping systems perspective.  

OpenAIRE

A methodology to objectively compare model components within a cropping systems model is introduced. It allows effective and efficient comparisons of modelling approaches with the help of a versatile cropping systems shell. This highly modular simulation environment allows inclusion of desired modules at the click of a button. The methodology is applied to some key wheat models currently in use for systems analysis and decision support in Australia. Thus, comprehensive data sets for model tes...

Meinke, H.

1996-01-01

335

crop and range alert system in the U.S. northern Great Plains  

Science.gov (United States)

The Upper Midwest Aerospace Consortium has developed a crop and range alert system to provide farmers, ranchers, land managers from the Native American Community, government agencies and non-governmental organizations with frequent and near real time remote sensing data to enable decisions that both maximize the producer's income and protect the environment. The project, started in 1999, includes the establishment of a learning community network of end users, fast delivery of data to remote locations, applications development and training. More than a hundred and fifty end users and research scientists participated in this learning group in which information is shared in all directions. Over fifty end users were connected via high-bandwidth satellite link to a central distribution system at the University of North Dakota. They received and shared products derived from AVHRR, MODIS, Landsat, IKONOS and aerial platforms. A number of practical applications were developed for precision farming, such as zone-based nitrogen management, stress detection, spray drift detection, and for rangeland management, such as weed detection, livestock carrying capacity, and livestock field rotations. Several instances of cost savings and higher earnings occurred. More importantly, the imagery use resulted in lesser use of chemicals in farming and ranching, leading to environmental benefits.

Seelan, Santhosh K.; Beeri, Ofer; Baumgardner, David; Casady, Grant; Laguette, Soizik; Seielstad, George

2003-03-01

336

Rhizo-lysimetry: facilities for the simultaneous study of root behaviour and resource use by agricultural crop and pasture systems  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Rhizo-lysimeters offer unique advantages for the study of plants and their interactions with soils. In this paper, an existing facility at Charles Sturt University in Wagga Wagga Australia is described in detail and its potential to conduct both ecophysiological and ecohydrological research in the study of root interactions of agricultural crops and pastures is quantitatively assessed. This is of significance to future crop research efforts in southern Australia, in light of recent significant long-term drought events, as well as potential impacts of climate change as predicted for the region. The rhizo-lysimeter root research facility has recently been expanded to accommodate larger research projects over multiple years and cropping rotations. Results Lucerne, a widely-grown perennial pasture in southern Australia, developed an expansive root system to a depth of 0.9 m over a twelve month period. Its deeper roots particularly at 2.05 m continued to expand for the duration of the experiment. In succeeding experiments, canola, a commonly grown annual crop, developed a more extensive (approximately 300% root system than wheat, but exhibited a slower rate of root elongation at rates of 7.47 x 10–3 m day–1 for canola and 1.04 x10–2 m day–1 for wheat. A time domain reflectometry (TDR network was designed to accurately assess changes in soil water content, and could assess water content change to within 5% of the amount of water applied. Conclusions The rhizo-lysimetry system provided robust estimates of root growth and soil water change under conditions representative of a field setting. This is currently one of a very limited number of global research facilities able to perform experimentation under field conditions and is the largest root research experimental laboratory in the southern hemisphere.

Eberbach Philip L

2013-01-01

337

Specimen rotation system of the WSU TRIGA-fueled reactor  

International Nuclear Information System (INIS)

The specimen rotation system presently in use at the WSU reactor has been designed to provide maximum utilization of the irradiation capabilities achieved through use of TRIGA-type fuel. This paper describes the system with particular emphasis on characteristics which are advantageous to experimenters. (author)

338

The influence of tagasaste (chamaecytisus proliferus link) trees on the water balance of an alley cropping system on deep sand in south-western Australia)  

International Nuclear Information System (INIS)

Components of the water balance of an alley cropping system were measured to assess the extent to which tree rows 30 m apart with access to a fresh, perched watertable at 5 m depth were able to capture deep drainage from an inter-cropped cereal-legume rotation. Neutron probe data showed that the 4-year-old trees, cut back to 0.6-m high at the beginning of the experiment, depleted soil water to 2, 4, and 8 m laterally from the tree rows in their first, second, and third years of coppice regrowth, respectively. Combining data from soil water depletion in summer and comparisons of deuterium/hydrogen ratios of groundwater, xylem sap of trees, and herbaceous plants, it was shown that tagasaste trees drew on soil water for 80% of their transpiration in the first winter and 40% in the second, while switching to near total dependence on groundwater each summer and early autumn. Tree water use on a whole plot basis was 170 mm in 1997 (68% from groundwater) v. 167 mm in 1998 (73% from groundwater). Recharge to the perched watertable was estimated to be 193 mm under sole crop in 1998 (52% of rainfall), reducing to 32 mm when uptake of groundwater by trees was included. The degree of complementarity between tagasaste trees and crops in alley cropping used for water management is quantified for 1998 by calculating the ratio of the distance over which trees reduced drainage to zero to the distance over which they reduced crop yield to zero. It is concluded that segregated monocultu It is concluded that segregated monocultures of trees and crops would be a more appropriate strategy than a closely integrated system such as alley cropping in this case. Copyright (2001) CSIRO Australia

339

Polar rotation angle identifies elliptic islands in unsteady dynamical systems  

CERN Document Server

We propose rotation inferred from the polar decomposition of the flow gradient as a diagnostic for elliptic (or vortex-type) invariant regions in non-autonomous dynamical systems. We consider here two- and three-dimensional systems, in which polar rotation can be characterized by a single angle. For this polar rotation angle (PRA), we derive explicit formulas using the singular values and vectors of the flow gradient. We find that closed level sets of the PRA reveal elliptic islands in great detail, and singular level sets of the PRA uncover centers of such islands. Both features turn out to be objective (frame-invariant) for two-dimensional systems. We illustrate the diagnostic power of PRA for elliptic structures on several examples.

Farazmand, Mohammad

2015-01-01

340

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

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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.

Patrick M. Carr

2013-07-01

341

Rotation, magnetism and metallicity of M dwarf systems  

Science.gov (United States)

Close M dwarf binaries and higher multiples allow the investigation of rotational evolution and mean magnetic flux unbiased from scatter in inclination angle and age since the orientation of the spin axis of the components is most likely parallel and the individual systems are coeval. Systems composed of an early-type (M0.0-M4.0) and a late-type (M4.0-M8.0) component offer the possibility to study differences in rotation and magnetism between partially and fully convective stars. We have selected 10 of the closest dM systems to determine the rotation velocities and the mean magnetic field strengths based on spectroscopic analysis of FeH lines of Wing-Ford transitions at 1 ?m observed with Very Large Telescope/CRIRES. We also studied the quality of our spectroscopic model regarding atmospheric parameters including metallicity. A modified version of the Molecular Zeeman Library (MZL) was used to compute Landég-factors for FeH lines. Magnetic spectral synthesis was performed with the SYNMAST code. We confirmed previously reported findings that less massive M dwarfs are braked less effectively than objects of earlier types. Strong surface magnetic fields were detected in primaries of four systems (GJ 852, GJ 234, LP 717-36 and GJ 3322), and in the secondary of the triple system GJ 852. We also confirm strong 2-kG magnetic field in the primary of the triple system GJ 2005. No fields could be accurately determined in rapidly rotating stars with ? sin i > 10 km s-1. For slowly and moderately rotating stars, we find the surface magnetic field strength to increase with the rotational velocity ? sin i which is consistent with other results from studying field stars. Based on observations made with European Southern Observatory (ESO) Telescopes at the Paranal Observatories under programme ID 81.D-0189.

Shulyak, D.; Seifahrt, A.; Reiners, A.; Kochukhov, O.; Piskunov, N.

2011-12-01

342

Nitrogen source effects on nitrous oxide emissions from irrigated cropping systems in Colorado. American Chemical Society Symposium Series  

Science.gov (United States)

Nitrogen (N) fertilization is essential in most irrigated cropping systems to optimize crop yields and economic returns. Application of inorganic N fertilizers to these cropping systems generally results in increased nitrous oxide (N2O-N) emissions. Nitrous oxide emissions resulting from the appli...

343

Nitrogen Release from Green Manure of Water Hyacinth in Rice Cropping Systems  

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Full Text Available Nitrogen derived from water hyacinth and recovered in rice crops was measured to evaluate the effect of different amounts of added water hyacinth residues into rice cultivation on the performance of rice crop, N derived (Ndev from residues and N recovery (Nrec in rice crop. Dry matter production and N yield of rice crop decreased significantly as the amounts of added water hyacinth increased. The Ndev from water hyacinth was significantly increased as amounts of added water hyacinth increased. In contrast, the Nrec in rice crop was significantly decreased as amounts of added water hyacinth increased. In conclusion different quantities of added water hyacinth residues influenced the performance of rice, and the N dynamics of soil-rice systems.

Didik Wisnu Widjajanto

2002-01-01

344

New portable sensor system for rotational seismic motion measurements  

International Nuclear Information System (INIS)

A new mechanical sensor system for recording the rotation of ground velocity has been constructed. It is based on measurements of differential motions between paired sensors mounted along the perimeter of a rigid (undeformable) disk. The elementary sensors creating the pairs are sensitive low-frequency geophones currently used in seismic exploration to record translational motions. The main features of the new rotational seismic sensor system are flat characteristics in the wide frequency range from 1 to 200 Hz and sensitivity limit of the order of 10-8 rad/s. Notable advantages are small dimensions, portability, easy installation and operation in the field, and the possibility of calibrating the geophones in situ simultaneously with the measurement. An important feature of the instrument is that it provides records of translational seismic motions together with rotations, which allows many important seismological applications. We have used the new sensor system to record the vertical rotation velocity due to a small earthquake of ML=2.2, which occurred within the earthquake swarm in Western Bohemia in autumn 2008. We found good agreement of the rotation record with the transverse acceleration as predicted by theory. This measurement demonstrates that this device has a much wider application than just to prospecting measurements, for which it was originally designed.

345

New portable sensor system for rotational seismic motion measurements.  

Science.gov (United States)

A new mechanical sensor system for recording the rotation of ground velocity has been constructed. It is based on measurements of differential motions between paired sensors mounted along the perimeter of a rigid (undeformable) disk. The elementary sensors creating the pairs are sensitive low-frequency geophones currently used in seismic exploration to record translational motions. The main features of the new rotational seismic sensor system are flat characteristics in the wide frequency range from 1 to 200 Hz and sensitivity limit of the order of 10(-8) rad/s. Notable advantages are small dimensions, portability, easy installation and operation in the field, and the possibility of calibrating the geophones in situ simultaneously with the measurement. An important feature of the instrument is that it provides records of translational seismic motions together with rotations, which allows many important seismological applications. We have used the new sensor system to record the vertical rotation velocity due to a small earthquake of M(L)=2.2, which occurred within the earthquake swarm in Western Bohemia in autumn 2008. We found good agreement of the rotation record with the transverse acceleration as predicted by theory. This measurement demonstrates that this device has a much wider application than just to prospecting measurements, for which it was originally designed. PMID:20815619

Brokesová, Johana; Málek, Jirí

2010-08-01

346

New portable sensor system for rotational seismic motion measurements  

Energy Technology Data Exchange (ETDEWEB)

A new mechanical sensor system for recording the rotation of ground velocity has been constructed. It is based on measurements of differential motions between paired sensors mounted along the perimeter of a rigid (undeformable) disk. The elementary sensors creating the pairs are sensitive low-frequency geophones currently used in seismic exploration to record translational motions. The main features of the new rotational seismic sensor system are flat characteristics in the wide frequency range from 1 to 200 Hz and sensitivity limit of the order of 10{sup -8} rad/s. Notable advantages are small dimensions, portability, easy installation and operation in the field, and the possibility of calibrating the geophones in situ simultaneously with the measurement. An important feature of the instrument is that it provides records of translational seismic motions together with rotations, which allows many important seismological applications. We have used the new sensor system to record the vertical rotation velocity due to a small earthquake of M{sub L}=2.2, which occurred within the earthquake swarm in Western Bohemia in autumn 2008. We found good agreement of the rotation record with the transverse acceleration as predicted by theory. This measurement demonstrates that this device has a much wider application than just to prospecting measurements, for which it was originally designed.

Brokesova, Johana [Department of Geophysics, Faculty of Mathematics and Physics, Charles University, V Holesovickach 2, 18000 Prague (Czech Republic); Malek, Jiri [Institute of Rock Structure and Mechanics, Czech Academy of Sciences, V Holesovickach 41, 18209 Prague (Czech Republic)

2010-08-15

347

PARÁMETROS HIDRÁULICOS DETERMINADOS EN UN ANDISOL BAJO DIFERENTES ROTACIONES CULTURALES DESPUÉS DE DIEZ AÑOS / Hydraulic parameters determinated in Andisol under different crop rotations after ten years  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Los parámetros Hidráulicos fueron medidos en un suelo de origen volcánico del Valle Central (Humic Haploxerands) bajo diferentes rotaciones culturales con distinto manejo agronómico e intensidad de uso del suelo y fueron agrupadas en cuatro rotaciones que incluyeron pradera y dos rotaciones intensiv [...] as, sin pradera. Las mediciones de conductividad Hidráulica saturada (Kfs) fueron realizadas in-situ. Se determinaron, además, dos parámetros Hidráulicos del suelo: El parámetro á y el potencial de flujo mátrico (?m). Todas las parcelas con pradera, dentro de la rotación tuvieron valores similares de Kfs. Las parcelas con rotaciones intensivas presentaron valores extremos el mayor y menor valor de Kfs, donde la rotación: remolacha-trigo-frejol-cebada, presentó el mayor Kfs (P?0,05) de todos los tratamientos. Nuestros resultados fueron apoyados por un análisis de correlación en que se determinó una significativa (P?0,05) relación entre Kfs y los parámetros Hidráulicos y potencial de flujo mátrico (?m). Abstract in english Hydraulic parameters were measured in a soil of volcanic origin of the Central Valley (Humic Haploxerands) under different crop rotations with different agricultural management and soil-use intensity that were grouped in four rotations that includ