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Sample records for crop rotation electronic

  1. Energy crops in rotation. A review

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-15

    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

  2. Examining cotton in rotation with rice and cotton in rotation with other crops using natural experiment

    Science.gov (United States)

    Sun, Ling; Zhu, Zesheng

    2017-08-01

    This paper is to show the ability of remote sensing image analysis combined with statistical analysis to characterize the environmental risk assessment of cotton in rotation with rice and cotton in rotation with other crops in two ways: (1) description of rotation period of cotton in rotation with rice and cotton in rotation with other crops by the observational study or natural experiment; (2) analysis of rotation period calculation of cotton in rotation with rice and cotton in rotation with other crops. Natural experimental results show that this new method is very promising for determining crop rotation period for estimating regional averages of environmental risk. When it is applied to determining crop rotation period, two requested remote sensing images of regional crop are required at least.

  3. Tropical rotation crops influence nematode densities and vegetable yields.

    Science.gov (United States)

    McSorley, R; Dickson, D W; de Brito, J A; Hochmuth, R C

    1994-09-01

    The effects of eight summer rotation crops on nematode densities and yields of subsequent spring vegetable crops were determined in field studies conducted in north Florida from 1991 to 1993. The crop sequence was as follows: (i) rotation crops during summer 1991; (ii) cover crop of rye (Secale cereale) during winter 1991-92; (iii) 'Lemondrop L' squash (Cucurbita pepo) during spring 1992; (iv) rotation crops during summer 1992; (v) rye during winter 1992-93; (vi) 'Classic' eggplant (Solanum melongena) during spring 1993. The eight summer crop rotation treatments were as follows: 'Hale' castor (Ricinus communis), velvetbean (Mucuna deeringiana), sesame (Sesamum indicum), American jointvetch (Aeschynomene americana), weed fallow, 'SX- 17' sorghum-sudangrass (Sorghum bicolor x S. sudanense), 'Kirby' soybean (Glycine max), and 'Clemson Spineless' okra (Hibiscus esculentus) as a control. Rotations with castor, velvetbean, American jointvetch, and sorghum-sudangrass were most effective in maintaining the lowest population densities of Meloidogyne spp. (a mixture of M. incognita race 1 and M. arenaria race 1), but Paratrichodorus minor built up in the sorghum-sudangrass rotation. Yield of squash was lower (P crops evaluated here may be useful for managing nematodes in the field and for improving yields of subsequent vegetable crops.

  4. Crop rotation modelling - A European model intercomparison

    DEFF Research Database (Denmark)

    Kollas, Chris; Kersebaum, Kurt C; Nendel, Claas

    2015-01-01

    Diversification of crop rotations is considered an option to increase the resilience of European crop production under climate change. So far, however, many crop simulation studies have focused on predicting single crops in separate one-year simulations. Here, we compared the capability of fiftee...

  5. Do green manures as winter cover crops impact the weediness and crop yield in an organic crop rotation?

    OpenAIRE

    Madsen, Helena; Talgre, Liina; Eremeev, Viacheslav; Alaru, Maarika; Kauer, Karin; Luik, Anne

    2016-01-01

    The effects of different winter cover crops and their combination with composted cattle manure on weeds and crop yields were investigated within a five-field crop rotation (barley undersown with red clover, red clover, winter wheat, pea, potato) in three organic cropping systems. The control system (Org 0) followed the rotation. In organic systems Org I and Org II the winter cover crops were used as follows: ryegrass (Lolium perenne L. in 2011/2012) and a mixture of winter oilseed-rape (Brass...

  6. Crop rotation impact on soil quality

    International Nuclear Information System (INIS)

    Aziz, I.; Ashraf, M.; Mahmood, T.; Islam, K.R.

    2011-01-01

    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%) 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)

  7. The role of short-rotation woody crops in sustainable development

    International Nuclear Information System (INIS)

    Shepard, J.P.; Tolbert, V.R.

    1996-01-01

    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

  8. Pea yield and its components in different crop rotations

    OpenAIRE

    Seibutis, Vytautas; Deveikytė, Irena

    2006-01-01

    The effects of the crop rotations (2-4 course) differing in duration on the formation of pea productivity elements and the yield were investigated in stationary field experiments in Dotnuva during 1997-2004. Averaged experimental data showed that the highest pea yield (3.70 t ha-1) was recorded in the three-course crop rotation (sugar beet-spring barley-pea), in the four-course (pea-winter wheat-sugar beet-spring barley) and two-course (pea-winter wheat) crop rotations the grain yield consist...

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

    Science.gov (United States)

    Meisner, Matthew H; Rosenheim, Jay A

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Matthew H Meisner

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

  11. Weed populations and crop rotations: exploring dynamics of a structured periodic system

    NARCIS (Netherlands)

    Mertens, S.K.; Bosch, F. van den; Heesterbeek, J.A.P.

    2002-01-01

    The periodic growing of a certain set of crops in a prescribed order, called a crop rotation, is considered to be an important tool for managing weed populations. Nevertheless, the effects of crop rotations on weed population dynamics are not well understood. Explanations for rotation effects on

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

    DEFF Research Database (Denmark)

    Knudsen, Marie Trydeman; Meyer-Aurich, A; Olesen, Jørgen E

    2014-01-01

    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....... 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....

  13. Identifying representative crop rotation patterns and grassland loss in the US Western Corn Belt

    Energy Technology Data Exchange (ETDEWEB)

    Sahajpal, Ritvik; Zhang, Xuesong; Izaurralde, Roberto C.; Gelfand, Ilya; Hurtt, George C.

    2014-10-01

    Crop rotations (the practice of growing crops on the same land in sequential seasons) reside at the core of agronomic management as they can influence key ecosystem services such as crop yields, carbon and nutrient cycling, soil erosion, water quality, pest and disease control. Despite the availability of the Cropland Data Layer (CDL) which provides remotely sensed data on crop type in the US on an annual basis, crop rotation patterns remain poorly mapped due to the lack of tools that allow for consistent and efficient analysis of multi-year CDLs. This study presents the Representative Crop Rotations Using Edit Distance (RECRUIT) algorithm, implemented as a Python software package, to select representative crop rotations by combining and analyzing multi-year CDLs. Using CDLs from 2010 to 2012 for 5 states in the US Midwest, we demonstrate the performance and parameter sensitivity of RECRUIT in selecting representative crop rotations that preserve crop area and capture land-use changes. Selecting only 82 representative crop rotations accounted for over 90% of the spatio-temporal variability of the more than 13,000 rotations obtained from combining the multi-year CDLs. Furthermore, the accuracy of the crop rotation product compared favorably with total state-wide planted crop area available from agricultural census data. The RECRUIT derived crop rotation product was used to detect land-use conversion from grassland to crop cultivation in a wetland dominated part of the US Midwest. Monoculture corn and monoculture soybean cropping were found to comprise the dominant land-use on the newly cultivated lands.

  14. Adapting crop rotations to climate change in regional impact modelling assessments.

    Science.gov (United States)

    Teixeira, Edmar I; de Ruiter, John; Ausseil, Anne-Gaelle; Daigneault, Adam; Johnstone, Paul; Holmes, Allister; Tait, Andrew; Ewert, Frank

    2018-03-01

    The environmental and economic sustainability of future cropping systems depends on adaptation to climate change. Adaptation studies commonly rely on agricultural systems models to integrate multiple components of production systems such as crops, weather, soil and farmers' management decisions. Previous adaptation studies have mostly focused on isolated monocultures. However, in many agricultural regions worldwide, multi-crop rotations better represent local production systems. It is unclear how adaptation interventions influence crops grown in sequences. We develop a catchment-scale assessment to investigate the effects of tactical adaptations (choice of genotype and sowing date) on yield and underlying crop-soil factors of rotations. Based on locally surveyed data, a silage-maize followed by catch-crop-wheat rotation was simulated with the APSIM model for the RCP 8.5 emission scenario, two time periods (1985-2004 and 2080-2100) and six climate models across the Kaituna catchment in New Zealand. Results showed that direction and magnitude of climate change impacts, and the response to adaptation, varied spatially and were affected by rotation carryover effects due to agronomical (e.g. timing of sowing and harvesting) and soil (e.g. residual nitrogen, N) aspects. For example, by adapting maize to early-sowing dates under a warmer climate, there was an advance in catch crop establishment which enhanced residual soil N uptake. This dynamics, however, differed with local environment and choice of short- or long-cycle maize genotypes. Adaptation was insufficient to neutralize rotation yield losses in lowlands but consistently enhanced yield gains in highlands, where other constraints limited arable cropping. The positive responses to adaptation were mainly due to increases in solar radiation interception across the entire growth season. These results provide deeper insights on the dynamics of climate change impacts for crop rotation systems. Such knowledge can be used

  15. ECONOMIC BACKGROUND CROP ROTATION AS A WAY TO PREVENT THE DEGRADATION OF AGRICULTURAL LANDSCAPES

    Directory of Open Access Journals (Sweden)

    Shevchenko O.

    2017-05-01

    Full Text Available This article explores that to successfully combat land degradation on lands occupied in agriculture, it is necessary to conduct complex soil conservation measures constitute a single interconnected system and protect soil from degradation. Found that rotation – a reasonable compromise between the main requirements of production, organization of territory and environment, placing crops in view of a favorable combination; compliance with acceptable saturation parameters optimally varying cultures, and thus the possible timing of a return to their previous cultivation while taking into account the duration of the accepted rotation. Determined that the implementation and observance of crop rotation and better ensure the replenishment of nutrients of the soil, improving and maintaining its favorable physical properties, prevent the emergence of weeds, pests and pathogens cultivated crops and preventing the depletion of soil degradation processes and development. Found that scientifically based crop rotation is the basis for the use of all complex farming practices, differentiated cultivation, rational use of fertilizers and caring for plants. Rotation is correct – it agroecosystem, which created the best conditions for growth and development of various crops, thus providing a growing high and stable yields, obtaining high quality products. Soil and climatic conditions, specialty farms, crops structure and their biological characteristics defined as the type of crop rotation and crop rotation order. Each rotation should be selected such status, which would provide the greatest yield per unit area of rational use of all land. Therefore, proper placement crops in crop rotation must necessarily take into account the requirements of crops to their predecessor, thus it must evaluate not only the direct action of the first culture, but also take into account the impact of the latter on the following crops rotation. On unproductive and degraded lands is

  16. Comparison of the effects of different crop rotation systems on winter ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-11-19

    Nov 19, 2008 ... were found the best crop rotation systems under rain-fed conditions of ... Crop rotation is one of the major cultural practices in the .... components such as seed weight in a spike, harvest index, seed ..... due to high prices of product belonging to fodder pea and ... was a cash crop in agricultural marketing.

  17. Weed control through crop rotation and alternative management practices

    Directory of Open Access Journals (Sweden)

    Böhm, Herwart

    2014-02-01

    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.

  18. Meeting the demand for crop production: the challenge of yield decline in crops grown in short rotations.

    Science.gov (United States)

    Bennett, Amanda J; Bending, Gary D; Chandler, David; Hilton, Sally; Mills, Peter

    2012-02-01

    There is a trend world-wide to grow crops in short rotation or in monoculture, particularly in conventional agriculture. This practice is becoming more prevalent due to a range of factors including economic market trends, technological advances, government incentives, and retailer and consumer demands. Land-use intensity will have to increase further in future in order to meet the demands of growing crops for both bioenergy and food production, and long rotations may not be considered viable or practical. However, evidence indicates that crops grown in short rotations or monoculture often suffer from yield decline compared to those grown in longer rotations or for the first time. Numerous factors have been hypothesised as contributing to yield decline, including biotic factors such as plant pathogens, deleterious rhizosphere microorganisms, mycorrhizas acting as pathogens, and allelopathy or autotoxicity of the crop, as well as abiotic factors such as land management practices and nutrient availability. In many cases, soil microorganisms have been implicated either directly or indirectly in yield decline. Although individual factors may be responsible for yield decline in some cases, it is more likely that combinations of factors interact to cause the problem. However, evidence confirming the precise role of these various factors is often lacking in field studies due to the complex nature of cropping systems and the numerous interactions that take place within them. Despite long-term knowledge of the yield-decline phenomenon, there are few tools to counteract it apart from reverting to longer crop rotations or break crops. Alternative cropping and management practices such as double-cropping or inter-cropping, tillage and organic amendments may prove valuable for combating some of the negative effects seen when crops are grown in short rotation. Plant breeding continues to be important, although this does require a specific breeding target to be identified. This

  19. Crop rotation biomass and arbuscular mycorrhizal fungi effects on sugarcane yield

    Energy Technology Data Exchange (ETDEWEB)

    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

    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)

  20. Short rotation Wood Crops Program

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-08-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Jorge González U

    2013-09-01

    Full Text Available 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 behavior 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.

  2. Effects of Tropical Rotation Crops on Meloidogyne arenaria Population Densities and Vegetable Yields in Microplots.

    Science.gov (United States)

    McSorley, R; Dickson, D W; de Brito, J A; Hewlett, T E; Frederick, J J

    1994-06-01

    The effects of 12 summer crop rotation treatments on population densities of Meloidogyne arenaria race 1 and on yields of subsequent spring vegetable crops were determined in microplots. The crop sequence was: (i) rotation crops during summer 1991 ; (ii) cover crop of rye (Secale cereale) during winter 1991-92; (iii) squash (Cucurbita pepo) during spring 1992; (iv) rotation crops during summer 1992; (v) rye during winter 1992-93; (vi) eggplant (Solanum melongena) during spring 1993. The 12 rotation treatments were castor (Ricinus communis), cotton (Gossypium hirsutum), velvetbean (Mucuna deeringiana), crotalaria (Crotalaria spectabilis), fallow, hairy indigo (Indigofera hirsuta), American jointvetch (Aeschynomene americana), sorghum-sudangrass (Sorghum bicolor x S. sudanense), soybean (Glycine max), horsebean (Canavalia ensiformis), sesame (Sesamum indicum), and peanut (Arachis hypogaea). Compared to peanut, the first eight rotation treatments resulted in lower (P crops may provide a means for depressing M. arenaria population densities on a short-term basis to enhance yields in a subsequent susceptible vegetable crop.

  3. Nitrogen and phosphorus effluent loads from a paddy-field district adopting collective crop rotation.

    Science.gov (United States)

    Hama, T; Aoki, T; Osuga, K; Sugiyama, S; Iwasaki, D

    2012-01-01

    Japanese paddy rice systems commonly adopt the rotation of vegetables, wheat and soybeans with paddy rice. Crop rotation may, however, increase the nutrient load in effluent discharged from the district because more fertilizer is applied to the rotation crops than is applied to paddy crops. We investigated a paddy-field district subject to collective crop rotation and quantified the annual nutrient load of effluent from the district in three consecutive years. The total annual exports of nitrogen and phosphorus over the investigation period ranged from 30.3 to 40.6 kg N ha(-1) and 2.62 to 3.13 kg P ha(-1). The results suggest that rotation cropping increases the effluent nutrient load because applied fertilizer is converted to nitrate, and surface runoff is increased due to the absence of shuttering boards at the field outlets.

  4. Effect of Tropical Rotation Crops on Meloidogyne incognita and Other Plant-Parasitic Nematodes.

    Science.gov (United States)

    McSorley, R; Dickson, D W

    1995-12-01

    In a field experiment conducted on sandy soil in Florida during the 1993 season, rotation crops of castor (Ricinus communis), velvetbean (Mucuna deeringina), 'Mississippi Silver' cowpea (Vigna unguiculata), American jointvetch (Aeschynomene americana), 'Dehapine 51' cotton (Gossypium hirsutum), and 'SX-17' sorghum-sudangrass (Sorghum bicolor x S. sudanense) were effective in maintaining low population densities (450/100 cm(3) soil) resulted after 'Clemson Spineless' okra (Hibiscus esculentus) and 'Kirby' soybean (Glycine max). Following a winter cover crop of rye (Secale cereale), densities of M. incognita following the six most effective rotation crops (1993 season) remained relatively low (crop planted in 1994, but increased by the end of the eggplant crop. The rotation crops planted during 1993 had little effect on yield of eggplant in 1994. Eggplant yield was inversely correlated with preplant densities (Pi) of Belonolaimus longicaudatus (r = -0.282; P crop cultivars were lower (P crops intended for suppression of individual Meloidogyne spp. be evaluated for their response to other nematode pests as well.

  5. Climate protection and energy crops. Potential for greenhouse gas emission reduction through crop rotation and crop planning

    International Nuclear Information System (INIS)

    Eckner, Jens; Peter, Christiane; Vetter, Armin

    2015-01-01

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

  6. Effect of crop rotation on soil nutrient balance and weediness in soddy podzolic organic farming fields

    Science.gov (United States)

    Zarina, Livija; Zarina, Liga

    2017-04-01

    The nutrient balance in different crop rotations under organic cropping system has been investigated in Latvia at the Institute of Agricultural Resources and Economics since 2006. Latvia is located in a humid and moderate climatic region where the rainfall exceeds evaporation (soil moisture coefficient > 1) and the soil moisture regime is characteristic with percolation. The average annual precipitation is 670-850 mm. The average temperature varies from -6.7° C in January to 16.5 °C in July. The growing season is 175 - 185 days. The most widespread are podzolic soils and mainly they are present in agricultural fields in all regions of Latvia. In a wider sense the goal of the soil management in organic farming is a creation of the biologically active flora and fauna in the soil by maintaining a high level of soil organic matter which is good for crops nutrient balance. Crop rotation is a central component of organic farming systems and has many benefits, including growth of soil microbial activity, which may increase nutrient availability. The aim of the present study was to calculate nutrient balance for each crop in the rotations and average in each rotation. Taking into account that crop rotations can limit build-up of weeds, additionally within the ERA-net CORE Organic Plus transnational programs supported project PRODIVA the information required for a better utilization of crop diversification for weed management in North European organic arable cropping systems was summarized. It was found that the nutrient balance was influenced by nutrients uptake by biomass of growing crops in crop rotation. The number of weeds in the organic farming fields with crop rotation is dependent on the cultivated crops and the succession of crops in the crop rotation.

  7. Evaluation of Different Phenological Information to Map Crop Rotation in Complex Irrigated Indus Basin

    Science.gov (United States)

    Ismaeel, A.; Zhou, Q.

    2018-04-01

    Accurate information of crop rotation in large basin is essential for policy decisions on land, water and nutrient resources around the world. Crop area estimation using low spatial resolution remote sensing data is challenging in a large heterogeneous basin having more than one cropping seasons. This study aims to evaluate the accuracy of two phenological datasets individually and in combined form to map crop rotations in complex irrigated Indus basin without image segmentation. Phenology information derived from Normalized Difference Vegetation Index (NDVI) and Leaf Area Index (LAI) of Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, having 8-day temporal and 1000 m spatial resolution, was used in the analysis. An unsupervised (temporal space clustering) to supervised (area knowledge and phenology behavior) classification approach was adopted to identify 13 crop rotations. Estimated crop area was compared with reported area collected by field census. Results reveal that combined dataset (NDVI*LAI) performs better in mapping wheat-rice, wheat-cotton and wheat-fodder rotation by attaining root mean square error (RMSE) of 34.55, 16.84, 20.58 and mean absolute percentage error (MAPE) of 24.56 %, 36.82 %, 30.21 % for wheat, rice and cotton crop respectively. For sugarcane crop mapping, LAI produce good results by achieving RMSE of 8.60 and MAPE of 34.58 %, as compared to NDVI (10.08, 40.53 %) and NDVI*LAI (10.83, 39.45 %). The availability of major crop rotation statistics provides insight to develop better strategies for land, water and nutrient accounting frameworks to improve agriculture productivity.

  8. EVALUATION OF DIFFERENT PHENOLOGICAL INFORMATION TO MAP CROP ROTATION IN COMPLEX IRRIGATED INDUS BASIN

    Directory of Open Access Journals (Sweden)

    A. Ismaeel

    2018-04-01

    Full Text Available Accurate information of crop rotation in large basin is essential for policy decisions on land, water and nutrient resources around the world. Crop area estimation using low spatial resolution remote sensing data is challenging in a large heterogeneous basin having more than one cropping seasons. This study aims to evaluate the accuracy of two phenological datasets individually and in combined form to map crop rotations in complex irrigated Indus basin without image segmentation. Phenology information derived from Normalized Difference Vegetation Index (NDVI and Leaf Area Index (LAI of Moderate Resolution Imaging Spectroradiometer (MODIS sensor, having 8-day temporal and 1000 m spatial resolution, was used in the analysis. An unsupervised (temporal space clustering to supervised (area knowledge and phenology behavior classification approach was adopted to identify 13 crop rotations. Estimated crop area was compared with reported area collected by field census. Results reveal that combined dataset (NDVI*LAI performs better in mapping wheat-rice, wheat-cotton and wheat-fodder rotation by attaining root mean square error (RMSE of 34.55, 16.84, 20.58 and mean absolute percentage error (MAPE of 24.56 %, 36.82 %, 30.21 % for wheat, rice and cotton crop respectively. For sugarcane crop mapping, LAI produce good results by achieving RMSE of 8.60 and MAPE of 34.58 %, as compared to NDVI (10.08, 40.53 % and NDVI*LAI (10.83, 39.45 %. The availability of major crop rotation statistics provides insight to develop better strategies for land, water and nutrient accounting frameworks to improve agriculture productivity.

  9. Plant Residual Management in different Crop Rotations System on Potato Tuber Yield Loss Affected by Wireworms

    Directory of Open Access Journals (Sweden)

    A. Zarea Feizabadi

    2016-07-01

    Full Text Available Introduction: Selection a proper crop rotation based on environmental conservation rules is a key factor for increasing long term productivity. On the other hand, the major problem in reaching agricultural sustainability is lack of soil organic matter. Recently, a new viewpoint has emerged based on efficient use of inputs, environmental protection, ecological economy, food supply and security. Crop rotation cannot supply and restore plant needed nutrients, so gradually the productivity of rotation system tends to be decreased. Returning the plant residues to the soil helps to increase its organic matter and fertility in long-term period. Wireworms are multi host pests and we can see them in wheat and barley too. The logic way for their control is agronomic practices like as crop rotation. Wireworms’ population and damages are increased with using grasses and small seed gramineas in mild winters, variation in cropping pattern, reduced chemical control, and cover crops in winter. In return soil cultivation, crop rotation, planting date, fertilizing, irrigation and field health are the examples for the effective factors in reducing wireworms’ damage. Materials and Methods: In order to study the effect of crop rotations, residue management and yield damage because of wireworms’ population in soil, this experiment was conducted using four rotation systems for five years in Jolgeh- Rokh agricultural research station. Crop rotations were included, 1 Wheat monoculture for the whole period (WWWWW, 2 Wheat- wheat- wheat- canola- wheat (WWWCW, 3 Wheat- sugar beet- wheat- potato- wheat (WSWPW, 4 Wheat- maize- wheat- potato- wheat (WMWPW as main plots and three levels of returning crop residues to soil (returning 0, 50 and 100% produced crop residues to soil were allocated as sub plots. This experiment was designed as split plot based on RCBD design with three replications. After ending each rotation treatment, the field was sowed with potato cv. Agria

  10. Biogas crops grown in energy crop rotations: Linking chemical composition and methane production characteristics.

    Science.gov (United States)

    Herrmann, Christiane; Idler, Christine; Heiermann, Monika

    2016-04-01

    Methane production characteristics and chemical composition of 405 silages from 43 different crop species were examined using uniform laboratory methods, with the aim to characterise a wide range of crop feedstocks from energy crop rotations and to identify main parameters that influence biomass quality for biogas production. Methane formation was analysed from chopped and over 90 days ensiled crop biomass in batch anaerobic digestion tests without further pre-treatment. Lignin content of crop biomass was found to be the most significant explanatory variable for specific methane yields while the methane content and methane production rates were mainly affected by the content of nitrogen-free extracts and neutral detergent fibre, respectively. The accumulation of butyric acid and alcohols during the ensiling process had significant impact on specific methane yields and methane contents of crop silages. It is proposed that products of silage fermentation should be considered when evaluating crop silages for biogas production. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Marta K. Kostrzewska

    2014-04-01

    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

  12. Mycobiome of Cysts of the Soybean Cyst Nematode Under Long Term Crop Rotation

    Science.gov (United States)

    Hu, Weiming; Strom, Noah; Haarith, Deepak; Chen, Senyu; Bushley, Kathryn E.

    2018-01-01

    The soybean cyst nematode (SCN), Heterodera glycines Ichinohe (Phylum Nematoda), is a major pathogen of soybean. It causes substantial yield losses worldwide and is difficult to control because the cyst protects the eggs which can remain viable for nearly a decade. Crop rotation with non-host crops and use of biocontrol organisms such as fungi and bacteria offer promising approaches, but remain hampered by lack of knowledge of the biology of nematode parasitic organisms. We used a high-throughput metabarcoding approach to characterize fungal communities associated with the SCN cyst, a microenvironment in soil that may harbor both nematode parasites and plant pathogens. SCN cysts were collected from a long-term crop rotation experiment in Southeastern Minnesota at three time points over two growing seasons to characterize diversity of fungi inhabiting cysts and to examine how crop rotation and seasonal variation affects fungal communities. A majority of fungi in cysts belonged to Ascomycota and Basidiomycota, but the presence of several early diverging fungal subphyla thought to be primarily plant and litter associated, including Mortierellomycotina and Glomeromycotina (e.g., arbuscular mycorrhizal fungi), suggests a possible role as nematode egg parasites. Species richness varied by both crop rotation and season and was higher in early years of crop rotation and in fall at the end of the growing season. Crop rotation and season also impacted fungal community composition and identified several classes of fungi, including Eurotiomycetes, Sordariomycetes, and Orbiliomycetes (e.g., nematode trapping fungi), with higher relative abundance in early soybean rotations. The relative abundance of several genera was correlated with increasing years of soybean. Fungal communities also varied by season and were most divergent at midseason. The percentage of OTUs assigned to Mortierellomycotina_cls_Incertae_sedis and Sordariomycetes increased at midseason, while Orbiliomycetes

  13. Mycobiome of Cysts of the Soybean Cyst Nematode Under Long Term Crop Rotation.

    Science.gov (United States)

    Hu, Weiming; Strom, Noah; Haarith, Deepak; Chen, Senyu; Bushley, Kathryn E

    2018-01-01

    The soybean cyst nematode (SCN), Heterodera glycines Ichinohe (Phylum Nematoda), is a major pathogen of soybean. It causes substantial yield losses worldwide and is difficult to control because the cyst protects the eggs which can remain viable for nearly a decade. Crop rotation with non-host crops and use of biocontrol organisms such as fungi and bacteria offer promising approaches, but remain hampered by lack of knowledge of the biology of nematode parasitic organisms. We used a high-throughput metabarcoding approach to characterize fungal communities associated with the SCN cyst, a microenvironment in soil that may harbor both nematode parasites and plant pathogens. SCN cysts were collected from a long-term crop rotation experiment in Southeastern Minnesota at three time points over two growing seasons to characterize diversity of fungi inhabiting cysts and to examine how crop rotation and seasonal variation affects fungal communities. A majority of fungi in cysts belonged to Ascomycota and Basidiomycota, but the presence of several early diverging fungal subphyla thought to be primarily plant and litter associated, including Mortierellomycotina and Glomeromycotina (e.g., arbuscular mycorrhizal fungi), suggests a possible role as nematode egg parasites. Species richness varied by both crop rotation and season and was higher in early years of crop rotation and in fall at the end of the growing season. Crop rotation and season also impacted fungal community composition and identified several classes of fungi, including Eurotiomycetes, Sordariomycetes, and Orbiliomycetes (e.g., nematode trapping fungi), with higher relative abundance in early soybean rotations. The relative abundance of several genera was correlated with increasing years of soybean. Fungal communities also varied by season and were most divergent at midseason. The percentage of OTUs assigned to Mortierellomycotina_cls_Incertae_sedis and Sordariomycetes increased at midseason, while Orbiliomycetes

  14. 70-79 Effects of Crop Rotation and NP Fertilizer Rate on Grain Yield a

    African Journals Online (AJOL)

    Primary nutrient (N, P and K) composition of the ... Crop rotation with fertilizer amendment improved the pH of the soil. Crop rotation and ..... Soil organic carbon contents declined regardless of inputs application for continuously cultivated land (Kapkiyai, 1996). Higher. Organic carbon content next to before planting (1.98 %).

  15. Soil carbon fractions in response to long-term crop rotations in the Loess Plateau of China

    Science.gov (United States)

    Diversified crop rotations may enhance C fractions and soil quality by affecting the quality and quantity of crop residue returned to the soil compared with monocropping and fallow. We evaluated the effect of 30-yr-old diversified crop rotations on soil C fractions at 0- to 15- and 15- to 30-cm dept...

  16. Power efficiency of mineral and organic fertilizers application in crop rotations

    OpenAIRE

    BOSAK V.M.

    2009-01-01

    In researches on sod podzolic light loamy soil the application of mineral and organic fertilizers has provided high indicators of agronomic and power efficiency. Entering of mineral fertilizers has raised efficiency of field crop rotations on 19,9-30,3 tha -1 of f.u., as well as entering of organic fertilizers on 5,2-10,8 tha -1 of f.u. at a recoupment of 1 ton of manure of 65,0-131,3 f.u. and 1 kg of NPK of 8,1-9,7 f.u. Power return of application of mineral fertilizers in crop rotations has...

  17. Closed Loop Short Rotation Woody Biomass Energy Crops

    Energy Technology Data Exchange (ETDEWEB)

    Brower, Michael [CRC Development, LLC, Oakland, CA (United States)

    2012-09-30

    CRC Development LLC is pursuing commercialization of shrub willow crops to evaluate and confirm estimates of yield, harvesting, transportation and renewable energy conversion costs and to provide a diverse resource in its supply portfolio.The goal of Closed Loop Short Rotation Woody Biomass Energy Crops is supply expansion in Central New York to facilitate the commercialization of willow biomass crops as part of the mix of woody biomass feedstocks for bioenergy and bioproducts. CRC Development LLC established the first commercial willow biomass plantation acreage in North America was established on the Tug Hill in the spring of 2006 and expanded in 2007. This was the first 230- acres toward the goal of 10,000 regional acres. This project replaces some 2007-drought damaged acreage and installs a total of 630-acre new planting acres in order to demonstrate to regional agricultural producers and rural land-owners the economic vitality of closed loop short rotation woody biomass energy crops when deployed commercially in order to motivate new grower entry into the market-place. The willow biomass will directly help stabilize the fuel supply for the Lyonsdale Biomass facility, which produces 19 MWe of power and exports 15,000 pph of process steam to Burrows Paper. This project will also provide feedstock to The Biorefinery in New York for the manufacture of renewable, CO2-neutral liquid transportation fuels, chemicals and polymers. This project helps end dependency on imported fossil fuels, adds to region economic and environmental vitality and contributes to national security through improved energy independence.

  18. Short Rotation Crops in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Wright, L L

    1998-06-04

    The report is based primarily on the results of survey questions sent to approximately 60 woody and 20 herbaceous crop researchers in the United States and on information from the U.S. Department of Energy's Bioenergy Feedstock Development Program. Responses were received from 13 individuals involved in woody crops research or industrial commercialization (with 5 of the responses coming from industry). Responses were received from 11 individuals involved in herbaceous crop research. Opinions on market incentives, technical and non-technical barriers, and highest priority research and development areas are summarized in the text. Details on research activities of the survey responders are provided as appendices to the paper. Woody crops grown as single-stem systems (primarily Populus and Eucalyptus species) are perceived to have strong pulp fiber and oriented strand board markets, and the survey responders anticipated that energy will comprise 25% or less of the utilization of single-stem short-rotation woody crops between now and 2010. The only exception was a response from California where a substantial biomass energy market does currently exist. Willows (Salix species) are only being developed for energy and only in one part of the United States at present. Responses from herbaceous crop researchers suggested frustration that markets (including biomass energy markets) do not currently exist for the crop, and it was the perception of many that federal incentives will be needed to create such markets. In all crops, responses indicate that a wide variety of research and development activities are needed to enhance the yields and profitability of the crops. Ongoing research activities funded by the U.S. Department of Energy's Bioenergy Feedstock Development Program are described in an appendix to the paper.

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

    DEFF Research Database (Denmark)

    Askegaard, M; Olesen, Jørgen E; Rasmussen, Ilse Ankjær

    2011-01-01

    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....../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...

  20. Performance of process-based models for simulation of grain N in crop rotations across Europe

    DEFF Research Database (Denmark)

    Yin, Xiaogang; Kersebaum, KC; Kollas, C

    2017-01-01

    The accurate estimation of crop grain nitrogen (N; N in grain yield) is crucial for optimizing agricultural N management, especially in crop rotations. In the present study, 12 process-based models were applied to simulate the grain N of i) seven crops in rotations, ii) across various pedo...... (Brassica napus L.). These differences are linked to the intensity of parameterization with better parameterized crops showing lower prediction errors. The model performance was influenced by N fertilization and irrigation treatments, and a majority of the predictions were more accurate under low N...

  1. Decoupling the deep: crop rotations, fertilization and soil physico-chemical properties down the profile

    Science.gov (United States)

    Hobley, Eleanor; Honermeier, Bernd; Don, Axel; Amelung, Wulf; Kögel-Knabner, Ingrid

    2017-04-01

    Crop fertilization provides vital plant nutrients (e.g. NPK) to ensure yield security but is also associated with negative environmental impacts. In particular, inorganic, mineral nitrogen (Nmin) fertilization leads to emissions during its energy intensive production as well as Nmin leaching to receiving waters. Incorporating legumes into crop rotations can provide organic N to the soil and subsequent crops, reducing the need for mineral N fertilizer and its negative environmental impacts. An added bonus is the potential to enhance soil organic carbon stocks, thereby reducing atmospheric CO2 concentrations. In this study we assessed the effects of legumes in rotation and fertilization regimes on the depth distribution - down to 1 m - of total soil nitrogen (Ntot), soil organic carbon (SOC) as well as isotopic composition (δ13C, δ15N), electrical conductivity and bulk density as well as agricultural yields at a long-term field experiment in Gießen, Germany. Fertilization had significant but small impacts on the soil chemical environment, most particularly the salt content of the soil, with PK fertilization increasing electrical conductivity throughout the soil profile. Similarly, fertilization resulted in a small reduction of soil pH throughout the soil profile. N fertilization, in particular, significantly increased yields, whereas PK fertilizer had only marginal yield effects, indicating that these systems are N limited. This N limitation was confirmed by significant yield benefits with leguminous crops in rotation, even in combination with mineral N fertilizer. The soil was physically and chemically influenced by the choice of crop rotation. Adding clover as a green mulch crop once every 4 years resulted in an enrichment of total N and SOC at the surface compared with fava beans and maize, but only in combination with PK fertilization. In contrast, fava beans and to a lesser extent maize in rotation lowered bulk densities in the subsoil compared with clover

  2. Generation of multi annual land use and crop rotation data for regional agro-ecosystem modeling

    Science.gov (United States)

    Waldhoff, G.; Lussem, U.; Sulis, M.; Bareth, G.

    2017-12-01

    For agro-ecosystem modeling on a regional scale with systems like the Community Land Model (CLM), detailed crop type and crop rotation information on the parcel-level is of key importance. Only with this, accurate assessments of the fluxes associated with the succession of crops and their management are possible. However, sophisticated agro-ecosystem modeling for large regions is only feasible at grid resolutions, which are much coarser than the spatial resolution of modern land use maps (usually ca. 30 m). As a result, much of the original information content of the maps has to be dismissed during resampling. Here we present our mapping approach for the Rur catchment (located in the west of Germany), which was developed to address these demands and issues. We integrated remote sensing and geographic information system (GIS) methods to classify multi temporal images of (e.g.) Landsat, RapidEye and Sentinel-2 to generate annual crop maps for the years 2008-2017 at 15 m spatial resolution (accuracy always ca. 90 %). A key aspect of our method is the consideration of crop phenology for the data selection and the analysis. In a GIS, the annul crop maps were integrated to a crop sequence dataset from which the major crop rotations were derived (based on the 10-years). To retain the multi annual crop succession and crop area information at coarser grid resolutions, cell-based land use fractions, including other land use classes were calculated for each year and for various target cell sizes (1-32 arc seconds). The resulting datasets contain the contribution (in percent) of every land use class to each cell. Our results show that parcels with the major crop types can be differentiated with a high accuracy and on an annual basis. The analysis of the crop sequence data revealed a very large number of different crop rotations, but only relatively few crop rotations cover larger areas. This strong diversity emphasizes the importance of information on crop rotations to reduce

  3. [Effects of tobacco garlic crop rotation and intercropping on tobacco yield and rhizosphere soil phosphorus fractions].

    Science.gov (United States)

    Tang, Biao; Zhang, Xi-zhou; Yang, Xian-bin

    2015-07-01

    A field plot experiment was conducted to investigate the tobacco yield and different forms of soil phosphorus under tobacco garlic crop rotation and intercropping patterns. The results showed that compared with tobacco monoculture, the tobacco yield and proportion of middle/high class of tobacco leaves to total leaves were significantly increased in tobacco garlic crop rotation and intercropping, and the rhizosphere soil available phosphorus contents were 1.3 and 1.7 times as high as that of tobacco monoculture at mature stage of lower leaf. For the inorganic phosphorus in rhizosphere and non-rhizosphere soil in different treatments, the contents of O-P and Fe-P were the highest, followed by Ca2-P and Al-P, and Ca8-P and Ca10-P were the lowest. Compared with tobacco monoculture and tobacco garlic crop intercropping, the Ca2-P concentration in rhizosphere soil under tobacco garlic crop rotation at mature stage of upper leaf, the Ca8-P concentration at mature stage of lower leaf, and the Ca10-P concentration at mature stage of middle leaf were lowest. The Al-P concentrations under tobacco garlic crop rotation and intercropping were 1.6 and 1.9 times, and 1.2 and 1.9 times as much as that under tobacco monoculture in rhizosphere soil at mature stages of lower leaf and middle leaf, respectively. The O-P concentrations in rhizosphere soil under tobacco garlic crop rotation and intercropping were significantly lower than that under tobacco monoculture. Compared with tobacco garlic crop intercropping, the tobacco garlic crop rotation could better improve tobacco yield and the proportion of high and middle class leaf by activating O-P, Ca10-P and resistant organic phosphorus in soil.

  4. Evaluation of oilseed crop rotations with agro-environmental indicators

    Directory of Open Access Journals (Sweden)

    Pouzet André

    2003-05-01

    Full Text Available The European Common Agricultural Policy is shifting an increasing part of the subsidies to eco-conditionality. Henceforth, it becomes essential to evaluate the environmental effect of agricultural practices, and more generally performances of cropping and farming systems, in order to design and to develop more sustainable systems. This assessment is being implemented for the main cropping systems of some French regions, using environmental indicators. Eleven exposure indicators were chosen in order to represent a wide range of specific sustainability objectives dealing with water, soil, air, non-renewable resources, biodiversity, and landscape. The results present the sustainability assessment for the crop rotations of Champagne Berrichonne region in the Centre of France.

  5. 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)

    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

    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

  6. Does nitrogen fertilizer application rate to corn affect nitrous oxide emissions from the rotated soybean crop?

    Science.gov (United States)

    Iqbal, Javed; Mitchell, David C; Barker, Daniel W; Miguez, Fernando; Sawyer, John E; Pantoja, Jose; Castellano, Michael J

    2015-05-01

    Little information exists on the potential for N fertilizer application to corn ( L.) to affect NO emissions during subsequent unfertilized crops in a rotation. To determine if N fertilizer application to corn affects NO emissions during subsequent crops in rotation, we measured NO emissions for 3 yr (2011-2013) in an Iowa, corn-soybean [ (L.) Merr.] rotation with three N fertilizer rates applied to corn (0 kg N ha, the recommended rate of 135 kg N ha, and a high rate of 225 kg N ha); soybean received no N fertilizer. We further investigated the potential for a winter cereal rye ( L.) cover crop to interact with N fertilizer rate to affect NO emissions from both crops. The cover crop did not consistently affect NO emissions. Across all years and irrespective of cover crop, N fertilizer application above the recommended rate resulted in a 16% increase in mean NO flux rate during the corn phase of the rotation. In 2 of the 3 yr, N fertilizer application to corn (0-225 kg N ha) did not affect mean NO flux rates from the subsequent unfertilized soybean crop. However, in 1 yr after a drought, mean NO flux rates from the soybean crops that received 135 and 225 kg N ha N application in the corn year were 35 and 70% higher than those from the soybean crop that received no N application in the corn year. Our results are consistent with previous studies demonstrating that cover crop effects on NO emissions are not easily generalizable. When N fertilizer affects NO emissions during a subsequent unfertilized crop, it will be important to determine if total fertilizer-induced NO emissions are altered or only spread across a greater period of time. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  7. [Influence of paddy rice-upland crop rotation of cold-waterlogged paddy field on crops produc- tion and soil characteristics].

    Science.gov (United States)

    Wang, Fei; Li, Qing-hua; Lin, Cheng; He, Chun-mei; Zhong, Shao-jie; Li, Yu; Lin, Xin-jian; Huang, Jian-cheng

    2015-05-01

    Two consecutive years (4-crop) experiments were conducted to study the influence of different paddy rice-upland crop rotation in cold-waterlogged paddy field on the growth of crops and soil characteristics. The result showed that compared with the rice-winter fallow (CK) pattern, the two-year average yield of paddy rice under four rotation modes, including rape-rice (R-R), spring corn-rice (C-R), Chinese milk vetch-rice (M-R) and bean-rice (B-R), were increased by 5.3%-26.7%, with significant difference observed in C-R and R-R patterns. Except for M-R pattern, the annual average total economic benefits were improved by 79.0%-392.4% in all rotation pattern compared with the CK, and the ration of output/input was enhanced by 0.06-0.72 unit, with the most significant effect found in the C-R pattern. Likewise, compared with the CK, the contents of chlorophyll and carotenoid, and net photosynthetic rate (Pn) of rice plant were all increased during the full-tillering stage of rice in all rotation patterns. The rusty lines and rusty spots of soils were more obvious compared with the CK during the rice harvest, particularly in R-R, C-R and B-R patterns. The ratio of water-stable soil macro aggregates of plough layer of soil (> 2 mm) decreased at different levels in all rotation patterns while the ratios of middle aggregate (0.25-2 mm, expect for M-R) and micro aggregate of soil (< 0.25 mm) were opposite. There was a decreasing trend for soil active reducing agents in all rotation patterns, whereas the available nutrient increased. The amounts of soil bacteria in C-R and B-R patterns, fungi in B-R rotation pattern, cellulose bacteria in R-R, C-R and B-R patterns and N-fixing bacteria in B-R pattern were improved by 285.7%-403.0%, 221.7%, 64.6-92.2% and 162.2%, respectively. Moreover, the differences in all microorganisms were significant. Thus, based on the experimental results of cold-waterlogged paddy field, it was concluded that changing from single cropping rice system

  8. Effect of crop rotations and fertilization on energy balance in typical production systems on the Canadian Prairies

    Energy Technology Data Exchange (ETDEWEB)

    Zentner, R.P.; Stumborg, M.A.; Campbell, C.A.

    1989-03-01

    Non-renewable energy inputs (both direct and indirect), metabolizable energy output and energy efficiency of 10 spring wheat (Triticum aestivum L.) rotations were examined over 18 years on a loam soil in the Brown soil zone of the Canadian Prairies. The rotations, which were managed using conventional tillage, included a range of crops, cropping intensities, crop sequences and fertilizer practices. Results showed that the total energy input per unit of land was lowest for the traditional fallow-wheat (F-W) rotation (3482 MJ ha/sup -1/), intermediate (4470 MJ ha/sup -1/) for N- and P-fertilized fallow-wheat-wheat (F-W-W) and highest for N- and P-fertilized continuous wheat (7100 MJ ha/sup -1/). Substituting flax (Linum usitatissimum L.) or rye (Secale cereale L.) for wheat in the rotations reduced total energy input by 3 to 8%, while withholding the application of either N or P fertilizer reduced total energy input by 16-37%. Liquid fuel for field operations and local product transport, and fertilizer (primarily N) were the major energy inputs; both increased with cropping intensity. Fuel accounted for 30-50% of the total energy input of the rotations. Fertilizer represented 15-49% of the total energy input and was more important than fuel for the continuous crop rotations. Despite the high energy content in pesticides, they accounted for only 4-11% of the total energy input of the rotations. Metabolizable energy output displayed similar response patterns as total energy input reflecting the higher total annual grain yields as cropping intensity increased. The average energy output to input ratio for F-W was 3.6, or 262 kg of wheat GJ/sup -1/ of energy input, while those for F-W-W and continuous wheat were 3.3 and 2.6, or 240 and 191 kg of wheat GJ/sup -1/ of energy input, respectively. Rotations that included flax or cereal forage crops had the lowest energy efficiencies. 2 figs., 31 refs., 4 tabs.

  9. Woody biomass from short rotation energy crops. Chapter 2

    Science.gov (United States)

    R.S., Jr. Zalesny Jr.; M.W. Cunningham; R.B. Hall; J. Mirck; D.L. Rockwood; J.A. Stanturf; T.A. Volk

    2011-01-01

    Short rotation woody crops (SRWCs) are ideal for woody biomass production and management systems because they are renewable energy feedstocks for biofuels, bioenergy, and bioproducts that can be strategically placed in the landscape to conserve soil and water, recycle nutrients, and sequester carbon. This chapter is a synthesis of the regional implications of producing...

  10. Multi-model uncertainty analysis in predicting grain N for crop rotations in Europe

    DEFF Research Database (Denmark)

    Yin, Xiaogang; Kersebaum, Kurt C; Kollas, Chris

    2017-01-01

    Realistic estimation of grain nitrogen (N; N in grain yield) is crucial for assessing N management in crop rotations, but there is little information on the performance of commonly used crop models for simulating grain N. Therefore, the objectives of the study were to (1) test if continuous simul...

  11. Supporting Agricultural Ecosystem Services through the Integration of Perennial Polycultures into Crop Rotations

    Directory of Open Access Journals (Sweden)

    Peter Weißhuhn

    2017-12-01

    Full Text Available This review analyzes the potential role and long-term effects of field perennial polycultures (mixtures in agricultural systems, with the aim of reducing the trade-offs between provisioning and regulating ecosystem services. First, crop rotations are identified as a suitable tool for the assessment of the long-term effects of perennial polycultures on ecosystem services, which are not visible at the single-crop level. Second, the ability of perennial polycultures to support ecosystem services when used in crop rotations is quantified through eight agricultural ecosystem services. Legume–grass mixtures and wildflower mixtures are used as examples of perennial polycultures, and compared with silage maize as a typical crop for biomass production. Perennial polycultures enhance soil fertility, soil protection, climate regulation, pollination, pest and weed control, and landscape aesthetics compared with maize. They also score lower for biomass production compared with maize, which confirms the trade-off between provisioning and regulating ecosystem services. However, the additional positive factors provided by perennial polycultures, such as reduced costs for mineral fertilizer, pesticides, and soil tillage, and a significant preceding crop effect that increases the yields of subsequent crops, should be taken into account. However, a full assessment of agricultural ecosystem services requires a more holistic analysis that is beyond the capabilities of current frameworks.

  12. Effects of crop rotation on weed density, biomass and yield of wheat (Titicum aestivum L.)

    OpenAIRE

    A. Zareafeizabadi; H.R. Rostamzadeh

    2016-01-01

    In order to study the weed populations in wheat, under different crop rotations an experiment was carried out at Agricultural Research Station of Jolgeh Rokh, Iran. During growing season this project was done in five years, based on Randomized Complete Bloch Design with three replications, on Crop rotations included: wheat monoculture for the whole period (WWWWW), wheat- wheat- wheat- canola- wheat (WWWCW), wheat- sugar beet- wheat-sugar beet- wheat (WSWSW), wheat- potato- wheat- potato- whea...

  13. Weed infestation of a cereal-legume mixture depending on its concentration and position in a crop rotation

    Directory of Open Access Journals (Sweden)

    Marta K. Kostrzewska

    2012-10-01

    Full Text Available A field study was carried out in the period 2000-2006 at the Experimental Station in Tomaszkowo belonging to the University of Warmia and Mazury in Olsztyn. Its aim was to compare weed infestation of a mixture of spring barley and field pea grown in a four crop rotation with different crop selection and sequence. Each year during tillering of spring barley and before the harvest of the mixture, weed species composition and density were evaluated, while additionally weed biomass was also estimated before the harvest. These results were used to determine species constancy, Simpson’s dominance index, the Shannon-Wiener diversity and evenness indices as well as the community similarity index based on floristic richness, numbers and biomass of particular weed species. The cropping frequency and the position of the mixture in the crop rotation did not differentiate the species composition and total biomass of weed communities in the cereal-legume mixture crops. The crop rotation in which the mixture constituted 50% and was grown after itself had a reducing effect on weed numbers. Growing field pea in the 4-year crop rotation promoted weed infestation of the mixture and the dominance of weed communities. Capsella bursa-pastoris, Chenopodium album, Echinochloa crus-galli, Elymus repens, Polygonum convolvulus, and Sonchus arvensis were constant components of the agrophytocenoses. The weed communities were more similar in terms of their floristic composition than in terms of weed density and air-dry weight of weeds.

  14. Effects of organic manure and crop rotation system on potato ...

    African Journals Online (AJOL)

    Effects of organic manure and crop rotation system on potato ( Solanum tuberosum L.) tuber ... Ethiopian Journal of Science and Technology ... (FYM); V2 = 2.5 t/h fresh sesbania green manure (FSB) V3 = 5 t/ha FYM; and V4 = 5 t/ha FYM +2.5 ...

  15. Optimal weed management in crop rotations: incorporating economics is crucial

    NARCIS (Netherlands)

    Berg, van den F.; Gilligan, C.A.; Lemmen-Gerdessen, van J.C.; Gregoire, L.A.H.; Bosch, van den F.

    2010-01-01

    Although the effects of crop rotation sequence and length on weed population dynamics have been studied, it is not clear whether or not the best strategy, from a weed population dynamics point of view, is also the economic optimal strategy. It is also not clear which biological and economic

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

    International Nuclear Information System (INIS)

    Tolbert, V.R.; Thornton, F.C.; Joslin, J.D.

    1997-01-01

    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)

  17. Review of Alternative Management Options of Vegetable Crop Residues to Reduce Nitrate Leaching in Intensive Vegetable Rotations

    Directory of Open Access Journals (Sweden)

    Laura Agneessens

    2014-12-01

    Full Text Available Vegetable crop residues take a particular position relative to arable crops due to often large amounts of biomass with a N content up to 200 kg N ha−1 left behind on the field. An important amount of vegetable crops are harvested during late autumn and despite decreasing soil temperatures during autumn, high rates of N mineralization and nitrification still occur. Vegetable crop residues may lead to considerable N losses through leaching during winter and pose a threat to meeting water quality objectives. However, at the same time vegetable crop residues are a vital link in closing the nutrient and organic matter cycle of soils. Appropriate and sustainable management is needed to harness the full potential of vegetable crop residues. Two fundamentally different crop residue management strategies to reduce N losses during winter in intensive vegetable rotations are reviewed, namely (i on-field management options and modifications to crop rotations and (ii removal of crop residues, followed by a useful and profitable application.

  18. How are arbuscular mycorrhizal associations related to maize growth performance during short-term cover crop rotation?

    Science.gov (United States)

    Higo, Masao; Takahashi, Yuichi; Gunji, Kento; Isobe, Katsunori

    2018-03-01

    Better cover crop management options aiming to maximize the benefits of arbuscular mycorrhizal fungi (AMF) to subsequent crops are largely unknown. We investigated the impact of cover crop management methods on maize growth performance and assemblages of AMF colonizing maize roots in a field trial. The cover crop treatments comprised Italian ryegrass, wheat, brown mustard and fallow in rotation with maize. The diversity of AMF communities among cover crops used for maize management was significantly influenced by the cover crop and time course. Cover crops did not affect grain yield and aboveground biomass of subsequent maize but affected early growth. A structural equation model indicated that the root colonization, AMF diversity and maize phosphorus uptake had direct strong positive effects on yield performance. AMF variables and maize performance were related directly or indirectly to maize grain yield, whereas root colonization had a positive effect on maize performance. AMF may be an essential factor that determines the success of cover crop rotational systems. Encouraging AMF associations can potentially benefit cover cropping systems. Therefore, it is imperative to consider AMF associations and crop phenology when making management decisions. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

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

    International Nuclear Information System (INIS)

    Drury, C.F.; Yang, X.M.; Reynolds, W.D.; McLaughlin, N.B.

    2008-01-01

    Nitrous oxide (N 2 O) and carbon dioxide (CO 2 ) 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 N 2 O 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 N 2 O and CO 2 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 N 2 O 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 N 2 O 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 N 2 O and CO 2 were attributed to higher inorganic nitrogen (N) application rates in corn crops. In the corn phase, CO 2 levels were higher when the preceding crop was winter wheat. It was concluded that N 2 O and CO 2 emissions from agricultural fields are influenced by both current and preceding crops, a fact which should be considered and accounted for in estimates and forecasts of agricultural greenhouse gas (GHG) emissions. 21 refs., 3 tabs., 10 figs

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

    Energy Technology Data Exchange (ETDEWEB)

    Drury, C.F.; Yang, X.M.; Reynolds, W.D. [Agriculture and Agri-Food Canada, Harrow, ON (Canada); McLaughlin, N.B. [Agriculture and Agri-Food Canada, Ottawa, ON (Canada). Eastern Cereal and Oilseed Research Centre

    2008-04-15

    Nitrous oxide (N{sub 2}O) and carbon dioxide (CO{sub 2}) 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 N{sub 2}O 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 N{sub 2}O and CO{sub 2} 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 N{sub 2}O 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 N{sub 2}O 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 N{sub 2}O and CO{sub 2} were attributed to higher inorganic nitrogen (N) application rates in corn crops. In the corn phase, CO{sub 2} levels were higher when the preceding crop was winter wheat. It was concluded that N{sub 2}O and CO{sub 2} emissions from agricultural fields are influenced by both current and preceding crops, a fact which should be considered and accounted for in estimates and forecasts of agricultural greenhouse gas (GHG) emissions. 21 refs., 3 tabs., 10 figs.

  1. The Effects of Cattle Manure and Garlic Rotation on Soil under Continuous Cropping of Watermelon (Citrullus lanatus L.).

    Science.gov (United States)

    Yang, Ruiping; Mo, Yanling; Liu, Changming; Wang, Yongqi; Ma, Jianxiang; Zhang, Yong; Li, Hao; Zhang, Xian

    2016-01-01

    Continuous cropping of watermelon (Citrullus lanatus L.) can lead to reduced yield and quality. We aimed to determine the effects of cattle manure addition and rotation with green garlic to improve yield and reduce disease incidence in watermelon and to examine the effects on the biological and chemical characteristics of the soil. Field experiments were performed during 2012-2014 on land previously under two years of continuous watermelon cropping in northwest China. We examined three treatment combinations: watermelon and garlic rotation, cattle manure application before watermelon planting, and combined cattle manure addition and crop rotation. Watermelon monoculture was retained as a control. Watermelon yield was significantly higher and disease incidence was lower in the treatments than the control. The populations of soil bacteria and actinomycetes and the bacteria/fungi ratio increased significantly and soil enzyme activities were generally enhanced under treatments. Available nutrients and soil organic matter contents were much higher under experimental treatments than the control. Results suggest both cattle manure application and garlic rotation can ameliorate the negative effects of continuous cropping. The combined treatment of cattle manure addition and green garlic rotation was optimal to increase yield, reduce disease incidence and enhance soil quality.

  2. Simulation of nitrogen leaching from a fertigated crop rotation in a Mediterranean climate using the EU-Rotate_N and Hydrus-2D models

    DEFF Research Database (Denmark)

    Doltra, Jordi; Nuñoz, P

    2010-01-01

    to a higher nitrate concentration in percolated water. Comparison of the observed and predicted yield response to N applications with EU-Rotate_N demonstrated that the best fertigation strategy could be identified and the risk of nitrate leaching quantified with this model. The results showed......Two different modeling approaches were used to simulate the N leached during an intensively fertigated crop rotation: a recently developed crop-based simulation model (EU-Rotate_N) and a widely recognized solute transport model (Hydrus-2D). Model performance was evaluated using data from...... an experiment where four N fertigation levels were applied to a bell pepper-cauliflower-Swiss chard rotation in a sandy loam soil. All the input data were obtained from measurements, transfer functions or were included in the model databases. Model runs were without specific site calibration. The use of soil...

  3. Soil tillage practices and crops rotations effects on yields and ...

    African Journals Online (AJOL)

    Methodology and Results: Three soil tillage practices in main plot (T1 = no tillage with direct sowing, T2 = minimum tillage by soil scarifying with IR12 tool and T3 = conventional tillage with animals drawn plough) were compared and combined to four crops rotation systems, in a split-plot experimental design. Soil chemical ...

  4. Crop rotations and poultry litter impact dynamic soil chemical properties and soil biota long-term

    Science.gov (United States)

    Dynamic soil physiochemical interactions with conservation agricultural practices and soil biota are largely unknown. Therefore, this study aims to quantify long-term (12-yr) impacts of cover crops, poultry litter, crop rotations, and conservation tillage and their interactions on soil physiochemica...

  5. PRACT (Prototyping Rotation and Association with Cover crop and no Till) - a tool for designing conservation agriculture systems

    NARCIS (Netherlands)

    Naudin, K.; Husson, M.O.; Scopel, E.; Auzoux, S.; Giller, K.E.

    2015-01-01

    Moving to more agroecological cropping systems implies deep changes in the organization of cropping systems. We propose a method for formalizing the process of innovating cropping system prototype design using a tool called PRACT (Prototyping Rotation and Association with Cover crop and no Till)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  7. Replacing fallow with forage triticale in dryland crop rotations increases profitability

    Science.gov (United States)

    A common dryland rotational cropping system in the semi-arid central Great Plains of the U.S. is wheat (Triticum aestivum L.)-corn (Zea mays L.)-fallow (WCF). However, the 12-month fallow period following corn production has been shown to be relatively inefficient in storing precipitation during the...

  8. The Effects of Cattle Manure and Garlic Rotation on Soil under Continuous Cropping of Watermelon (Citrullus lanatus L.)

    Science.gov (United States)

    Liu, Changming; Wang, Yongqi; Ma, Jianxiang; Zhang, Yong; Li, Hao; Zhang, Xian

    2016-01-01

    Continuous cropping of watermelon (Citrullus lanatus L.) can lead to reduced yield and quality. We aimed to determine the effects of cattle manure addition and rotation with green garlic to improve yield and reduce disease incidence in watermelon and to examine the effects on the biological and chemical characteristics of the soil. Field experiments were performed during 2012–2014 on land previously under two years of continuous watermelon cropping in northwest China. We examined three treatment combinations: watermelon and garlic rotation, cattle manure application before watermelon planting, and combined cattle manure addition and crop rotation. Watermelon monoculture was retained as a control. Watermelon yield was significantly higher and disease incidence was lower in the treatments than the control. The populations of soil bacteria and actinomycetes and the bacteria/fungi ratio increased significantly and soil enzyme activities were generally enhanced under treatments. Available nutrients and soil organic matter contents were much higher under experimental treatments than the control. Results suggest both cattle manure application and garlic rotation can ameliorate the negative effects of continuous cropping. The combined treatment of cattle manure addition and green garlic rotation was optimal to increase yield, reduce disease incidence and enhance soil quality. PMID:27258145

  9. Effects of ditch-buried straw return on water percolation, nitrogen leaching and crop yields in a rice-wheat rotation system.

    Science.gov (United States)

    Yang, Haishui; Xu, Mingmin; Koide, Roger T; Liu, Qian; Dai, Yajun; Liu, Ling; Bian, Xinmin

    2016-03-15

    Crop residue management and nitrogen loss are two important environmental problems in the rice-wheat rotation system in China. This study investigated the effects of burial of straw on water percolation, nitrogen loss by leaching, crop growth and yield. Greenhouse mesocosm experiments were conducted over the course of three simulated cropping seasons in a rice1-wheat-rice2 rotation. Greater amounts of straw resulted in more water percolation, irrespective of crop season. Burial at 20 and 35 cm significantly reduced, but burial at 50 cm increased nitrogen leaching. Straw at 500 kg ha(-1) reduced, but at 1000 kg ha(-1) and at 1500 kg ha(-1) straw increased nitrogen leaching in three consecutive crop rotations. In addition, straw at 500 kg ha(-1) buried at 35 cm significantly increased yield and its components for both crops. This study suggests that N losses via leaching from the rice-wheat rotation may be reduced by the burial of the appropriate amount of straw at the appropriate depth. Greater amounts of buried straw, however, may promote nitrogen leaching and negatively affect crop growth and yields. Complementary field experiments must be performed to make specific agronomic recommendations. © 2015 Society of Chemical Industry.

  10. Can phosphorus application and cover cropping alter arbuscular mycorrhizal fungal communities and soybean performance after a five-year phosphorus-unfertilized crop rotational system?

    Science.gov (United States)

    Higo, Masao; Sato, Ryohei; Serizawa, Ayu; Takahashi, Yuichi; Gunji, Kento; Tatewaki, Yuya; Isobe, Katsunori

    2018-01-01

    Understanding diversity of arbuscular mycorrhizal fungi (AMF) is important for optimizing their role for phosphorus (P) nutrition of soybeans ( Glycine max (L.) Merr.) in P-limited soils. However, it is not clear how soybean growth and P nutrition is related to AMF colonization and diversity of AMF communities in a continuous P-unfertilized cover cropping system. Thus, we investigated the impact of P-application and cover cropping on the interaction among AMF colonization, AMF diversity in soybean roots, soybean growth and P nutrition under a five-year P-unfertilized crop rotation. In this study, we established three cover crop systems (wheat, red clover and oilseed rape) or bare fallow in rotation with soybean. The P-application rates before the seeding of soybeans were 52.5 and 157.5 kg ha -1 in 2014 and 2015, respectively. We measured AMF colonization in soybean roots, soybean growth parameters such as aboveground plant biomass, P uptake at the flowering stage and grain yields at the maturity stage in both years. AMF community structure in soybean roots was characterized by specific amplification of small subunit rDNA. The increase in the root colonization at the flowering stage was small as a result of P-application. Cover cropping did not affect the aboveground biomass and P uptake of soybean in both years, but the P-application had positive effects on the soybean performance such as plant P uptake, biomass and grain yield in 2015. AMF communities colonizing soybean roots were also significantly influenced by P-application throughout the two years. Moreover, the diversity of AMF communities in roots was significantly influenced by P-application and cover cropping in both years, and was positively correlated with the soybean biomass, P uptake and grain yield throughout the two years. Our results indicated that P-application rather than cover cropping may be a key factor for improving soybean growth performance with respect to AMF diversity in P-limited cover

  11. Characteristics of Nitrogen and Phosphorus Effluent Load from a Paddy-field District Implementing Crop Rotation

    Science.gov (United States)

    Hama, Takehide; Aoki, Takeru; Osuga, Katsuyuki; Nakamura, Kimihito; Sugiyama, Sho; Kawashima, Shigeto

    Implementation of collective crop rotation in a paddy-field district may increase nutrients effluent load. We have investigated a paddy-field district implementing collective crop rotation of wheat and soybeans, measured temporal variations in nutrients concentration of drainage water and the amount of discharged water for consecutive three years, and estimated nutrients effluent load from the district during the irrigation and non-irrigation periods. As a result, the highest concentration of nutrients was observed during the non-irrigation period in every investigation year. It was shown that high nutrients concentration of drainage water during the non-irrigation period was caused by runoff of fertilizer applied to wheat because the peaks of nutrients concentration of drainage water were seen in rainy days after fertilizer application in the crop-rotation field. The effluent load during the non-irrigation periods was 16.9-22.1 kgN ha-1 (nitrogen) and 0.84-1.42 kgP ha-1 (phosphorus), which respectively accounted for 46-66% and 27-54% of annual nutrients effluent load.

  12. Impact of wheat / faba bean mixed cropping or rotation systems on soil microbial functionalities

    Directory of Open Access Journals (Sweden)

    Sanâa Wahbi

    2016-09-01

    Full Text Available Cropping systems based on carefully designed species mixtures reveal many potential advantages in terms of enhancing crop productivity, reducing pest and diseases and enhacing ecological serices. Associating cereals and legume production either through intercropping or rotations might be a relevant strategy of producing both type of culture, while benefiting from combined nitrogen fixed by the legume through its symbiotic association with nitrogen-fixing bacteria, and from a better use of P and water through mycorrhizal associations. These practices also participate to the diversification of agricultural productions, enabling to secure the regularity of income returns across the seasonal and climatic uncertainties. In this context, we designed a field experiment aiming to estimate the two years impact of these practices on wheat yield and on soil microbial activities as estimated through Substrate Induced Respiration (SIR method and mycorrhizal soil infectivity (MSI measurement. It is expected that understanding soil microbial functionalities in response to these agricultural practices might allows to target the best type of combination, in regard to crop productivity. We found that the tested cropping systems largely impacted soil microbial functionalities and mycorrhizal soil infectivity. Intercropping gave better results in terms of crop productivity than the rotation practice after 2 cropping seasons. Benefits resulting from intercrop should be highly linked with changes recorded on soil microbial functionalities.

  13. Soil Labile Organic Matter under Long-term Crop Rotation System

    Science.gov (United States)

    Saljnikov, E.

    2009-04-01

    Temperate grassland soils, typically Mollisols, have remained agriculturally productive with limited inputs for many years, despite the mining of energy and nutrients reserves contained within the soil organic fraction (Janzen, 1987; Tiessen et al., 1994). Such system can be considered resilient, at least initially, but one must question for how long such systems can be sustained. Effect of long-term land-use on biologically active fractions of soil organic matter is not well understood. Investigations were conducted in more than 40-year static experiments in northern Kazakhstan. We examined five fallow-wheat (Triticum aestivum L.) cropping systems with different frequencies of the fallow phase: continuous wheat (CW), 6-y rotation (6R), 4-y rotation (4R), 2-y rotation (2R) and continuous fallow (CF). A unique sample from nationally protected virgin steppe near the experimental field was sampled for comparison with long-term cultivated soils. Soil samples were collected from the two phases of each rotation, pre- and post-fallow, and analyzed for biological soil properties that are potentially mineralizable C (PMC), potentially mineralizable N (PMN), microbial biomass C (MBC) and N (MBN) and "light fraction" C (LFC) and N (LFN). Potentially mineralizable C was inversely proportional to the frequency of fallow and was highest in CW. Potentially mineralizable N was more responsive to rotation phase than other indices of SOM. Light fraction OM was negatively correlated to the frequency of fallow and was higher in pre-fallow than in post-fallow phases. All studied biological characteristics were drastically greater in the soil from the natural steppe. The results suggested that the yearly input of plant residues in a less frequently fallowed system built up more PMC, whereas PMN was closely correlated to recent inputs of substrate added as plant residue. We concluded that a frequent fallowing for long period may deplete SOM via accelerated mineralization. The results may

  14. Long-term C-CO2 emissions and carbon crop residue mineralization in an oxisol under different tillage and crop rotation systems

    Directory of Open Access Journals (Sweden)

    Ben-Hur Costa de Campos

    2011-06-01

    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

  15. Cover crop rotations in no-till system: short-term CO2 emissions and soybean yield

    Directory of Open Access Journals (Sweden)

    João Paulo Gonsiorkiewicz Rigon

    Full Text Available ABSTRACT: In addition to improving sustainability in cropping systems, the use of a spring and winter crop rotation system may be a viable option for mitigating soil CO2 emissions (ECO2. This study aimed to determine short-term ECO2 as affected by crop rotations and soil management over one soybean cycle in two no-till experiments, and to assess the soybean yields with the lowest ECO2. Two experiments were carried out in fall-winter as follows: i triticale and sunflower were grown in Typic Rhodudalf (TR, and ii ruzigrass, grain sorghum, and ruzigrass + grain sorghum were grown in Rhodic Hapludox (RH. In the spring, pearl millet, sunn hemp, and forage sorghum were grown in both experiments. In addition, in TR a fallow treatment was also applied in the spring. Soybean was grown every year in the summer, and ECO2 were recorded during the growing period. The average ECO2 was 0.58 and 0.84 g m2 h–1 with accumulated ECO2 of 5,268 and 7,813 kg ha–1 C-CO2 in TR and RH, respectively. Sunn hemp, when compared to pearl millet, resulted in lower ECO2 by up to 12 % and an increase in soybean yield of 9% in TR. In RH, under the winter crop Ruzigrazz+Sorghum, ECO2 were lower by 17%, although with the same soybean yield. Soil moisture and N content of crop residues are the main drivers of ECO2 and soil clay content seems to play an important role in ECO2 that is worthy of further studies. In conclusion, sunn hemp in crop rotation may be utilized to mitigate ECO2 and improve soybean yield.

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

    Science.gov (United States)

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

    2016-12-01

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

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

    International Nuclear Information System (INIS)

    Wright, L.L.; Ranney, J.W.

    1991-01-01

    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

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

    DEFF Research Database (Denmark)

    Doltra, Jordi; Lægdsmand, Mette; Olesen, Jørgen E

    2011-01-01

    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...... 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...

  19. Evaluation of the Effect of Crop Rotations on Yield and Yield Components of Bread Wheat (Triticum aestivum L. cv. Darya)

    OpenAIRE

    H. A. Fallahi; U. Mahmadyarov; H. Sabouri; M. Ezat-Ahmadi4

    2013-01-01

    Grain yield in wheat is influenced directly and indirectly by other plant characteristics. One of the main goals in wheat breeding programs is increase of grain yield. Considering the role of crop rotation in increasing grain yield, and in order to study the difference between crop rotations for wheat yield and yield components (Darya cultivar), an experiment was conducted with six rotation treatments (wheat-chickpea-wheat, wheat-cotton-wheat, wheat-watermelon-wheat, wheat-wheat-wheat, wheat-...

  20. Species composition and density of weeds in a wheat crop depending on the soil tillage system in crop rotation

    Directory of Open Access Journals (Sweden)

    P. Yankov

    2015-03-01

    Full Text Available Abstract. The investigation was carried out in the trial field of Dobrudzha Agricultural Institute, General Toshevo on slightly leached chernozem soil type. For the purposes of this investigation, variants from a stationary field experiment initiated in 1987 and based on various soil tillage tools and operations were analyzed. The species composition and density of weeds were followed in a wheat crop grown after grain maize using the following soil tillage systems: plowing at 24 – 26 cm (for maize – disking at 10 – 12 cm (for wheat; cutting at 24 – 26 cm (for maize – cutting at 8 – 10 cm (for wheat; disking at 10 – 12 cm (for maize – disking at 10 – 12 cm (for wheat; no-tillage (for maize – no-tillage (for wheat.Weed infestation was read at the fourth rotation since the initiation of the trial. The observations were made in spring before treatment of the crop with herbicides. The soil tillage system had a significant effect on the species composition and density of weeds in the field with wheat grown after previous crop maize. The long-term alternation of plowing with disking in parallel with the usage of chemicals for weed control lead to lower weed infestation of the weed crop. The lower weed density after this soil tillage system was not related to changes in the species composition and the relative percent of the individual species in the total weed infestation. The long-term application in crop rotation of systems without turning of the soil layer and of minimal and no-tillage increased the amount of weeds. The reason is the greater variability of weed species which typically occur after shallow soil tillage.

  1. Carbon storage and recycling in short-rotation energy crops

    International Nuclear Information System (INIS)

    Ranney, J.W.; Wright, L.L.; Mitchell, C.P.

    1991-01-01

    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

  2. Performance of process-based models for simulation of grain N in crop rotations across Europe

    Czech Academy of Sciences Publication Activity Database

    Xiaogang, Y.; Kesebaum, K. C.; Kollas, C.; Manevski, K.; Baby, S.; Beaudoin, N.; Öztürk, I.; Gaiser, T.; Wu, L.; Hoffmann, M.; Charfeddine, M.; Conradt, T.; Constantin, J.; Ewert, F.; de Cortazar-Atauri, I. G.; Giglio, L.; Hlavinka, Petr; Hoffmann, H.; Launay, M.; Louarn, G.; Manderscheid, R.; Mary, B.; Mirschel, W.; Nendel, C.; Pacholski, A.; Palouso, T.; Ripoche-Wachter, D.; Rötter, R. P.; Ruget, F.; Sharif, B.; Trnka, Miroslav; Ventrella, D.; Weigel, H-J.; Olesen, J. E.

    2017-01-01

    Roč. 154, JUN (2017), s. 63-77 ISSN 0308-521X R&D Projects: GA MŠk(CZ) LO1415; GA MZe QJ1310123 Institutional support: RVO:67179843 Keywords : Calibration * Crop model * Crop rotation * Grain N content * Model evaluation * Model initialization Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 2.571, year: 2016

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

    International Nuclear Information System (INIS)

    Radhakrishnan, R.; Lee, I.J.

    2014-01-01

    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

  4. Cover Crop-Based, Organic Rotational No-Till Corn and Soybean Production Systems in the Mid-Atlantic United States

    Directory of Open Access Journals (Sweden)

    John M. Wallace

    2017-04-01

    Full Text Available Cover crop-based, organic rotational no-till (CCORNT corn and soybean production is becoming a viable strategy for reducing tillage in organic annual grain systems in the mid-Atlantic, United States. This strategy relies on mechanical termination of cover crops with a roller-crimper and no-till planting corn and soybean into cover crop mulches. Here, we report on recent research that focuses on integrated approaches for crop, nutrient and pest management in CCORNT systems that consider system and regional constraints for adoption in the mid-Atlantic. Our research suggests that no-till planting soybean into roller-crimped cereal rye can produce consistent yields. However, constraints to fertility management have produced less consistent no-till corn yields. Our research shows that grass-legume mixtures can improve N-release synchrony with corn demand and also improve weed suppression. Integration of high-residue inter-row cultivation improves weed control consistency and may reduce reliance on optimizing cover crop biomass accumulation for weed suppression. System-specific strategies are needed to address volunteer cover crops in later rotational phases, which result from incomplete cover crop termination with the roller crimper. The paucity of adequate machinery for optimizing establishment of cash crops into thick residue mulch remains a major constraint on CCORNT adoption. Similarly, breeding efforts are needed to improve cover crop germplasm and develop regionally-adapted varieties.

  5. Combining Biophysical and Price Simulations to Assess the Economics of Long-Term Crop Rotations

    OpenAIRE

    Murray-Prior, Roy B.; Whish, J.; Carberry, Peter S.; Dalgleish, N.

    2003-01-01

    Biophysical simulation models (e.g. APSIM) using historical rainfall data are increasingly being used to provide yield and other data on crop rotations in various regions of Australia. However, to analyse the economics of these rotations it is desirable to incorporate the other main driver of profitability, price variation. Because the context was that APSIM was being used to simulate an existing trial site being monitored by a farmer group Gross Margin output was considered most appropriate....

  6. Carbon balance of the typical grain crop rotation in Moscow region assessed by eddy covariance method

    Science.gov (United States)

    Meshalkina, Joulia; Yaroslavtsev, Alexis; Vassenev, Ivan

    2017-04-01

    Croplands could have equal or even greater net ecosystem production than several natural ecosystems (Hollinger et al., 2004), so agriculture plays a substantial role in mitigation strategies for the reduction of carbon dioxide emissions. In Central Russia, where agricultural soils carbon loses are 9 time higher than natural (forest's) soils ones (Stolbovoi, 2002), the reduction of carbon dioxide emissions in agroecosystems must be the central focus of the scientific efforts. Although the balance of the CO2 mostly attributed to management practices, limited information exists regarding the crop rotation overall as potential of C sequestration. In this study, we present data on carbon balance of the typical grain crop rotation in Moscow region followed for 4 years by measuring CO2 fluxes by paired eddy covariance stations (EC). The study was conducted at the Precision Farming Experimental Fields of the Russian Timiryazev State Agricultural University, Moscow, Russia. The experimental site has a temperate and continental climate and situated in south taiga zone with Arable Sod-Podzoluvisols (Albeluvisols Umbric). Two fields of the four-course rotation were studied in 2013-2016. Crop rotation included winter wheat (Triticum sativum L.), barley (Hordeum vulgare L.), potato crop (Solanum tuberosum L.) and cereal-legume mixture (Vicia sativa L. and Avena sativa L.). Crops sowing occurred during the period from mid-April to mid-May depending on weather conditions. Winter wheat was sown in the very beginning of September and the next year it occurred from under the snow in the phase of tillering. White mustard (Sinapis alba) was sown for green manure after harvesting winter wheat in mid of July. Barley was harvested in mid of August, potato crop was harvested in September. Cereal-legume mixture on herbage was collected depending on the weather from early July to mid-August. Carbon uptake (NEE negative values) was registered only for the fields with winter wheat and white

  7. Tropical Legume Crop Rotation and Nitrogen Fertilizer Effects on Agronomic and Nitrogen Efficiency of Rice

    Directory of Open Access Journals (Sweden)

    Motior M. Rahman

    2014-01-01

    Full Text Available Bush bean, long bean, mung bean, and winged bean plants were grown with N fertilizer at rates of 0, 2, 4, and 6 g N m−2 preceding rice planting. Concurrently, rice was grown with N fertilizer at rates of 0, 4, 8, and 12 g N m−2. No chemical fertilizer was used in the 2nd year of crop to estimate the nitrogen agronomic efficiency (NAE, nitrogen recovery efficiency (NRE, N uptake, and rice yield when legume crops were grown in rotation with rice. Rice after winged bean grown with N at the rate of 4 g N m−2 achieved significantly higher NRE, NAE, and N uptake in both years. Rice after winged bean grown without N fertilizer produced 13–23% higher grain yield than rice after fallow rotation with 8 g N m−2. The results revealed that rice after winged bean without fertilizer and rice after long bean with N fertilizer at the rate of 4 g N m−2 can produce rice yield equivalent to that of rice after fallow with N fertilizer at rates of 8 g N m−2. The NAE, NRE, and harvest index values for rice after winged bean or other legume crop rotation indicated a positive response for rice production without deteriorating soil fertility.

  8. Colonisation of winter wheat grain by Fusarium spp. and mycotoxin content as dependent on a wheat variety, crop rotation, a crop management system and weather conditions.

    Science.gov (United States)

    Czaban, Janusz; Wróblewska, Barbara; Sułek, Alicja; Mikos, Marzena; Boguszewska, Edyta; Podolska, Grażyna; Nieróbca, Anna

    2015-01-01

    Field experiments were conducted during three consecutive growing seasons (2007/08, 2008/09 and 2009/10) with four winter wheat (Triticum aestivum L.) cultivars - 'Bogatka', 'Kris', 'Satyna' and 'Tonacja' - grown on fields with a three-field crop rotation (winter triticale, spring barley, winter wheat) and in a four-field crop rotation experiment (spring wheat, spring cereals, winter rapeseed, winter wheat). After the harvest, kernels were surface disinfected with 2% NaOCl and then analysed for the internal infection by different species of Fusarium. Fusaria were isolated on Czapek-Dox iprodione dichloran agar medium and identified on the basis of macro- and micro-morphology on potato dextrose agar and synthetic nutrient agar media. The total wheat grain infection by Fusarium depended mainly on relative humidity (RH) and a rainfall during the flowering stage. Intensive rainfall and high RH in 2009 and 2010 in the period meant the proportions of infected kernels by the fungi were much higher than those in 2008 (lack of precipitation during anthesis). Weather conditions during the post-anthesis period changed the species composition of Fusarium communities internally colonising winter wheat grain. The cultivars significantly varied in the proportion of infected kernels by Fusarium spp. The growing season and type of crop rotation had a distinct effect on species composition of Fusarium communities colonising the grain inside. A trend of a higher percentage of the colonised kernels by the fungi in the grain from the systems using more fertilisers and pesticides as well as the buried straw could be perceived. The most frequent species in the grain were F. avenaceum, F. tricinctum and F. poae in 2008, and F. avenaceum, F. graminearum, F. tricinctum and F. poae in 2009 and 2010. The contents of deoxynivalenol and zearalenon in the grain were correlated with the percentage of kernels colonised by F. graminearum and were the highest in 2009 in the grain from the four

  9. Yield trends in the long-term crop rotation with organic and inorganic fertilisers on Alisols in Mata (Rwanda)

    NARCIS (Netherlands)

    Rutunga, V.; Neel, H.

    2006-01-01

    A crop rotation system with various species was established on Alisols at Mata grassland site, oriental side of Zaire-Nile Watershed Divide (CZN), Rwanda. Inorganic and organic fertilizers were applied in various plots under randomized complete blocs with three replicates. Crop yield data for each

  10. The Energy Effectiveness Of Crops In Crop Rotation Under Different Soil Tillage Systems

    Directory of Open Access Journals (Sweden)

    Strašil Zdeněk

    2015-09-01

    Full Text Available The paper identifies and compares the energy balance of winter wheat, spring barley and white mustard – all grown in crop rotation under different tillage conditions. The field trial included the conventional tillage (CT method, minimum tillage (MT and a system with no tillage (NT. The energy inputs included both the direct and indirect energy component. Energy outputs are evaluated as gross calorific value (gross heating value of phytomass dry matter of the primary product and the total harvested production. The energy effectiveness (energy output: energy input was selected for evaluation. The greatest energy effectiveness for the primary product was established as 6.35 for barley, 6.04 for wheat and 3.68 for mustard; in the case of total production, it was 9.82 for barley, 10.08 for wheat and 9.72 for mustard. When comparing the different tillage conditions, the greatest energy effectiveness was calculated for the evaluated crops under the MT operation and represented the primary product of wheat at 6.49, barley at 6.69 and mustard at 3.92. The smallest energy effectiveness for the primary product was found in wheat 5.77 and barley 6.10 under the CT option; it was 3.55 for mustard under the option of NT. Throughout the entire cropping pattern, the greatest energy effectiveness was established under the minimum tillage option – 5.70 for the primary product and 10.47 for the total production. On the other hand, the smallest values were calculated under CT – 5.22 for the primary product and 9.71 for total production.

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

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Heck, R; Deen, B

    2013-01-01

    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...

  12. Effect of no-tillage crop rotation systems on nutrient status of a rhodic ...

    African Journals Online (AJOL)

    In this study the effects of no-tillage and eight crop rotations (established in 1985) on chemical properties of a Rhodic Ferralsol (Typic Haplorthox, Soil Taxonomy) and on nutrient uptake by maize (Zea mays L.) and soybean (Glycine max L. Merrill) leaves were assessed in the state of São Paulo, Brazil, using a randomized ...

  13. 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)

    Brozyna, Michal Adam; Petersen, Søren O; Chirinda, Ngoni

    2013-01-01

    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...... 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...

  14. Microbiological parameters as indicators of soil quality under various soil management and crop rotation systems in southern Brazil.

    OpenAIRE

    FRANCHINI, J. C.; CRISPINO, C. C.; SOUZA, R. A.; TORRES, E.; HUNGRIA, M.

    2006-01-01

    Metadata only record This article attempts to recognize soil parameters that can be used to monitor soil quality under different crop and soil management systems. The rates of CO2 emissions (soil respiration) were affected by variations in the sampling period, as well as in soil management and crop rotation. Considering all samples, CO2 emissions were 21% greater in conventional tillage. Soil microbial biomass was also influenced by sampling period and soil management, but not by crop rota...

  15. Ultra high energy electrons powered by pulsar rotation.

    Science.gov (United States)

    Mahajan, Swadesh; Machabeli, George; Osmanov, Zaza; Chkheidze, Nino

    2013-01-01

    A new mechanism of particle acceleration, driven by the rotational slow down of the Crab pulsar, is explored. The rotation, through the time dependent centrifugal force, can efficiently excite unstable Langmuir waves in the electron-positron (hereafter e(±)) plasma of the star magnetosphere. These waves, then, Landau damp on electrons accelerating them in the process. The net transfer of energy is optimal when the wave growth and the Landau damping times are comparable and are both very short compared to the star rotation time. We show, by detailed calculations, that these are precisely the conditions for the parameters of the Crab pulsar. This highly efficient route for energy transfer allows the electrons in the primary beam to be catapulted to multiple TeV (~ 100 TeV) and even PeV energy domain. It is expected that the proposed mechanism may, unravel the puzzle of the origin of ultra high energy cosmic ray electrons.

  16. Nitrate leaching and residual effect in dairy crop rotations with grass-clover leys as influenced by sward age, grazing, cutting and fertilizer regimes

    DEFF Research Database (Denmark)

    Eriksen, Jørgen; Askegaard, Margrethe; Rasmussen, Jim

    2015-01-01

    Intensive dairy farming, with grass-arable crop rotations is challenged by low N use efficiency that may have adverse environmental consequences. We investigated nitrate leaching and N fertility effects of grass–clover leys for five years in two organic crop rotations with different grassland...... with the 2-yr-old leaching the most (36–46 kg N ha−1), and (4) high leaching (>50 kg N ha−1) with lupin and maize, where especially maize was consistently high in all five years (average 81 kg N ha−1). Great care should be taken during all phases of the dairy crop rotation where grasslands cause considerable...... build-up of fertility. With due care and the best management practice, nitrate leaching losses may be reduced to low levels....

  17. Particulate Organic Matter Affects Soil Nitrogen Mineralization under Two Crop Rotation Systems.

    Directory of Open Access Journals (Sweden)

    Rongyan Bu

    Full Text Available Changes in the quantity and/or quality of soil labile organic matter between and after different types of cultivation system could play a dominant role in soil nitrogen (N mineralization. The quantity and quality of particulate organic matter (POM and potentially mineralizable-N (PMN contents were measured in soils from 16 paired rice-rapeseed (RR/cotton-rapeseed (CR rotations sites in Hubei province, central China. Then four paired soils encompassing low (10th percentile, intermediate (25th and 75th percentiles, and high (90th percentile levels of soil PMN were selected to further study the effects of POM on soil N mineralization by quantifying the net N mineralization in original soils and soils from which POM was removed. Both soil POM carbon (POM-C and N (POM-N contents were 45.8% and 55.8% higher under the RR rotation compared to the CR rotation, respectively. The PMN contents were highly correlated with the POM contents. The PMN and microbial biomass N (MBN contents concurrently and significantly decreased when POM was removed. The reduction rate of PMN was positively correlated with changes in MBN after the removal of POM. The reduction rates of PMN and MBN after POM removal are lower under RR rotations (38.0% and 16.3%, respectively than CR rotations (45.6% and 19.5%, respectively. Furthermore, infrared spectroscopy indicated that compounds with low-bioavailability accumulated (e.g., aromatic recalcitrant materials in the soil POM fraction under the RR rotation but not under the CR rotation. The results of the present study demonstrated that POM plays a vital role in soil N mineralization under different rotation systems. The discrepancy between POM content and composition resulting from different crop rotation systems caused differences in N mineralization in soils.

  18. Comparison of bacteria diversity between tobacco plantation soils of rotational cropping and continuous cropping%烤烟轮作与连作土壤细菌群落多样性比较

    Institute of Scientific and Technical Information of China (English)

    段玉琪; 晋艳; 陈泽斌; 夏振远; 杨宇虹; 徐照丽

    2012-01-01

    Total DNA of microbe in rotational cropping and continuous cropping soil were extracted and amplified by PCR with universally bacteria-specific rDNA primers. Clone libraries were set up to evaluate responses of soil bacteria community to different tobacco cropping systems (rotational and continuous cropping). PCR-RFLP analysis was carried out with restriction endonuclease Hae III and Afa I. 147 and 177 types of restriction endonuclease were obtained from these samples. Statistical analysis using diversity index measurement showed both Shannon-wiener index and species richness of rotational cropping soil were higher than that in continuous cropping soil. Bacterial phylogenetic trees of the samples revealed that Acidobacteria was dominant group in continuous cropping soil library while acidobacteria,γ-pro-teobacterium, α-proteobacterium were in rotational cropping soil library. It indicated that rotational farming system could improve bacterial diversity of soil while continuous cropping could simplify bacterial community structure. This phenomenon might cause functional disorder in bacterial community and destruction of ecological balance in rhizosphere soil. It might be one of the factors resulted in continuous cropping obstacle.%为了解烤烟轮作和连作对土壤细菌群落多样性的影响,分别提取轮作和连作土壤总DNA,用细菌16S rDNA特异引物扩增出细菌16S rDNA,建立克隆文库.用限制性内切酶Hae Ⅲ和AfaⅠ进行PCR-RFLP分析,分别得到177和147个酶切类型,采用多样性指数对试验结果进行分析统计表明,香农多样性指数和丰富度指数均表现为轮作大于连作.通过构建两克隆文库的系统发育树,并分析主要种群的组成表明:连作文库的优势种群主要集中在酸杆菌门,轮作文库的优势种群主要分布在酸杆菌门、γ-变形菌门、α-变形菌门.说明轮作方式可提高植烟土壤细菌群落的多样性,而连作使植烟土壤细菌群落结构趋于简单,从而导致微生物群落功能失调,可能是引发连作障碍的原因之一.

  19. Crop rotation in the Valle Calido del Alto Magdalena a sustainable focus of high yield

    International Nuclear Information System (INIS)

    Alfaro Rodriguez, Ricardo; Maria Caicedo, Antonio; Amezquita Collazos, Edgar; Castro Franco, Hugo Eduardo

    1996-01-01

    Experiments were carried out during five years at the Nataima Research Center, located at 431 m.a.s.l, with average temperature of 28 Celsius degrades and annual rainfall of 1274 Boyaca mm, on a soil classified as Arenic Haplustalf, to evaluate different crops rotation based on rice and sorghum; the combinations used were as follows; rice-rice (R-R), rice-- soybean (R-SY), rice-crotalaria-sorghum (R-C-S), sorghum-sorghum (S-S), sorghum-soybean (S-SY) and cotton-sorghum (Al-S). Simultaneously it was evaluated the response to four nitrogen levels, which allowed to find out yield functions and optimum economical. The rotations S-SY, R-SY and AI-S have been the best qualified from an environmental perspective. Sorghum-soybean rotation presents increases in yield compared with expected values, which allows thinking that it is a truly sustainable rotation. This rotation also had an excellent profitability and for that reason is considered the best option within the goals of this work

  20. Control of π-Electron Rotations in Chiral Aromatic Molecules Using Intense Laser Pulses

    Science.gov (United States)

    Kanno, Manabu; Kono, Hirohiko; Fujimura, Yuichi

    Our recent theoretical studies on laser-induced π-electron rotations in chiral aromatic molecules are reviewed. π electrons of a chiral aromatic molecule can be rotated along its aromatic ring by a nonhelical, linearly polarized laser pulse. An ansa aromatic molecule with a six-membered ring, 2,5-dichloro[n](3,6) pyrazinophane, which belongs to a planar-chiral molecule group, and its simplified molecule 2,5-dichloropyrazine are taken as model molecules. Electron wavepacket simulations in the frozen-molecular-vibration approximation show that the initial direction of π-electron rotation depends on the polarization direction of a linearly polarized laser pulse applied. Consecutive unidirectional rotation can be achieved by applying a sequence of linearly polarized pump and dump pulses to prevent reverse rotation. Optimal control simulations of π-electron rotation show that another controlling factor for unidirectional rotation is the relative optical phase between the different frequency components of an incident pulse in addition to photon polarization direction. Effects of nonadiabatic coupling between π-electron rotation and molecular vibrations are also presented, where the constraints of the frozen approximation are removed. The angular momentum gradually decays mainly owing to nonadiabatic coupling, while the vibrational amplitudes greatly depend on their rotation direction. This suggests that the direction of π-electron rotation on an attosecond timescale can be identified by detecting femtosecond molecular vibrations.

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

    Directory of Open Access Journals (Sweden)

    Piotr WOJEWÓDZKI

    2012-12-01

    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.

  2. Can an Electron Rotate a Brick?

    Science.gov (United States)

    Bohren, Craig F.

    2009-01-01

    In "The Theory of Almost Everything", Robert Oerter asserts the following: "Take a beam of electrons that are all spinning in the same direction and fire it at, say, a brick. If you could keep this up for long enough, and if there were no other forces acting on the brick, the electrons would transfer their rotation to the brick, and it would begin…

  3. Greenhouse Gas Emissions and Global Warming Potential of Traditional and Diversified Tropical Rice Rotation Systems including Impacts of Upland Crop Management Practices i.e. Mulching and Inter-crop Cultivation

    Science.gov (United States)

    Janz, Baldur; Weller, Sebastian; Kraus, David; Wassmann, Reiner; Butterbach-Bahl, Klaus; Kiese, Ralf

    2016-04-01

    Paddy rice cultivation is increasingly challenged by irrigation water scarcity, while at the same time changes in demand (e.g. changes in diets or increasing demand for biofuels) will feed back on agricultural practices. These factors are changing traditional cropping patterns from flooded double-rice systems to the introduction of well-aerated upland crop systems in the dry season. Emissions of methane (CH4) are expected to decrease, while emissions of nitrous oxide (N2O) will increase and soil organic carbon (SOC) stocks will most likely be volatilized in the form of carbon dioxide (CO2). We measured greenhouse gas (GHG) emissions at the International Rice Research Institute (IRRI) in the Philippines to provide a comparative assessment of the global warming potentials (GWP) as well as yield scaled GWPs of different crop rotations and to evaluate mitigation potentials or risks of new management practices i.e. mulching and inter-crop cultivation. New management practices of mulching and intercrop cultivation will also have the potential to change SOC dynamics, thus can play the key role in contributing to the GWP of upland cropping systems. To present, more than three years of continuous measurement data of CH4 and N2O emissions in double-rice cropping (R-R) and paddy rice rotations diversified with either maize (R-M) or aerobic rice (R-A) in upland cultivation have been collected. Introduction of upland crops in the dry season reduced irrigation water use and CH4 emissions by 66-81% and 95-99%, respectively. Moreover, for practices including upland crops, CH4 emissions in the subsequent wet season with paddy rice were reduced by 54-60%. Although annual N2O emissions increased twice- to threefold in the diversified systems, the strong reduction of CH4 led to a significantly lower (pbalance but also with regard to soil fertility. New upland crop management practices where first implemented during land-preparation for dry season (July) 2015 where i) 6t/ha rice straw

  4. The Response to P-Derived from Phosphate Rock and TSP by Crops Grown in a Simulated Crop Rotation System

    International Nuclear Information System (INIS)

    Sisworo, Elsye L; Sisworo, Widjang H; Havid-Rasjid; Syamsul-Rizal; Komarudin-Idris

    2002-01-01

    A green house experiment was carried out on a simulated crop rotation system of upland rice-soybean-mungbean to determine the effect of P-derived from different phosphate rock (PR) sources and TSP using 32 P. The data obtained reveal that all the P-sources has a significant effect on the growth of all the three crops, expressed in dry weight, % P-total and total P-uptake (mg P pot -1 ). For the P-source it was shown that % P-derived from PR/TSP and their uptake (mg P pot -1 ) was quite high, showing that the PR s applied were of good reactivity. The residue of the PR s has also still a good effect on plant growth than that of TSP. The efficiency of PR s was far below that of TSP. This apparently was due to the high rate of application, ten times the rate of TSP. (author)

  5. Effect of Mixed Systems on Crop Productivity

    Science.gov (United States)

    Senturklu, Songul; Landblom, Douglas; Cihacek, Larry; Brevik, Eric

    2017-04-01

    The goals of this non-irrigated research has been to determine the effect of mixed systems integration on crop, soil, and beef cattle production in the northern Great Plains region of the United States. Over a 5-year period, growing spring wheat (HRSW-C) continuously year after year was compared to a 5-year crop rotation that included spring wheat (HRSW-R), cover crop (dual crop consisting of winter triticale/hairy vetch seeded in the fall and harvested for hay followed by a 7-species cover crop that was seeded in June after hay harvest), forage corn, field pea/barley, and sunflower. Control 5-year HRSW yield was 2690 kg/ha compared to 2757 kg/ha for HRSW grown in rotation. Available soil nitrogen (N) is often the most important limitation for crop production. Expensive fertilizer inputs were reduced in this study due to the mixed system's complementarity in which the rotation system that included beef cattle grazing sustained N availability and increased nutrient cycling, which had a positive effect on all crops grown in the rotation. Growing HRSW continuously requires less intensive management and in this research was 14.5% less profitable. Whereas, when crop management increased and complementing crops were grown in rotation to produce crops and provide feed for grazing livestock, soil nutrient cycling improved. Increased nutrient cycling increased crop rotation yields and yearling beef cattle steers that grazing annual forages in the rotation gain more body weight than similar steers grazing NGP native range. Results of this long-term research will be presented in a PICO format for participant discussion.

  6. Impacts of Watershed Characteristics and Crop Rotations on Winter Cover Crop Nitrate-Nitrogen Uptake Capacity within Agricultural Watersheds in the Chesapeake Bay Region.

    Science.gov (United States)

    Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M; McCarty, Gregory W; Hively, W Dean; Lang, Megan W

    2016-01-01

    The adoption rate of winter cover crops (WCCs) as an effective conservation management practice to help reduce agricultural nutrient loads in the Chesapeake Bay (CB) is increasing. However, the WCC potential for water quality improvement has not been fully realized at the watershed scale. This study was conducted to evaluate the long-term impact of WCCs on hydrology and NO3-N loads in two adjacent watersheds and to identify key management factors that affect the effectiveness of WCCs using the Soil and Water Assessment Tool (SWAT) and statistical methods. Simulation results indicated that WCCs are effective for reducing NO3-N loads and their performance varied based on planting date, species, soil characteristics, and crop rotations. Early-planted WCCs outperformed late-planted WCCs on the reduction of NO3-N loads and early-planted rye (RE) reduced NO3-N loads by ~49.3% compared to the baseline (no WCC). The WCCs were more effective in a watershed dominated by well-drained soils with increased reductions in NO3-N fluxes of ~2.5 kg N·ha-1 delivered to streams and ~10.1 kg N·ha-1 leached into groundwater compared to poorly-drained soils. Well-drained agricultural lands had higher transport of NO3-N in the soil profile and groundwater due to increased N leaching. Poorly-drained agricultural lands had lower NO3-N due to extensive drainage ditches and anaerobic soil conditions promoting denitrification. The performance of WCCs varied by crop rotations (i.e., continuous corn and corn-soybean), with increased N uptake following soybean crops due to the increased soil mineral N availability by mineralization of soybean residue compared to corn residue. The WCCs can reduce N leaching where baseline NO3-N loads are high in well-drained soils and/or when residual and mineralized N availability is high due to the cropping practices. The findings suggested that WCC implementation plans should be established in watersheds according to local edaphic and agronomic

  7. Impacts of Watershed Characteristics and Crop Rotations on Winter Cover Crop Nitrate-Nitrogen Uptake Capacity within Agricultural Watersheds in the Chesapeake Bay Region.

    Directory of Open Access Journals (Sweden)

    Sangchul Lee

    Full Text Available The adoption rate of winter cover crops (WCCs as an effective conservation management practice to help reduce agricultural nutrient loads in the Chesapeake Bay (CB is increasing. However, the WCC potential for water quality improvement has not been fully realized at the watershed scale. This study was conducted to evaluate the long-term impact of WCCs on hydrology and NO3-N loads in two adjacent watersheds and to identify key management factors that affect the effectiveness of WCCs using the Soil and Water Assessment Tool (SWAT and statistical methods. Simulation results indicated that WCCs are effective for reducing NO3-N loads and their performance varied based on planting date, species, soil characteristics, and crop rotations. Early-planted WCCs outperformed late-planted WCCs on the reduction of NO3-N loads and early-planted rye (RE reduced NO3-N loads by ~49.3% compared to the baseline (no WCC. The WCCs were more effective in a watershed dominated by well-drained soils with increased reductions in NO3-N fluxes of ~2.5 kg N·ha-1 delivered to streams and ~10.1 kg N·ha-1 leached into groundwater compared to poorly-drained soils. Well-drained agricultural lands had higher transport of NO3-N in the soil profile and groundwater due to increased N leaching. Poorly-drained agricultural lands had lower NO3-N due to extensive drainage ditches and anaerobic soil conditions promoting denitrification. The performance of WCCs varied by crop rotations (i.e., continuous corn and corn-soybean, with increased N uptake following soybean crops due to the increased soil mineral N availability by mineralization of soybean residue compared to corn residue. The WCCs can reduce N leaching where baseline NO3-N loads are high in well-drained soils and/or when residual and mineralized N availability is high due to the cropping practices. The findings suggested that WCC implementation plans should be established in watersheds according to local edaphic and agronomic

  8. Cultivation-Based and Molecular Assessment of Bacterial Diversity in the Rhizosheath of Wheat under Different Crop Rotations.

    Directory of Open Access Journals (Sweden)

    Muhammad Tahir

    Full Text Available A field study was conducted to compare the formationand bacterial communities of rhizosheaths of wheat grown under wheat-cotton and wheat-rice rotation and to study the effects of bacterial inoculation on plant growth. Inoculation of Azospirillum sp. WS-1 and Bacillus sp. T-34 to wheat plants increased root length, root and shoot dry weight and dry weight of rhizosheathsoil when compared to non-inoculated control plants, and under both crop rotations. Comparing both crop rotations, root length, root and shoot dry weight and dry weight of soil attached with roots were higher under wheat-cotton rotation. Organic acids (citric acid, malic acid, acetic acid and oxalic acid were detected in rhizosheaths from both rotations, with malic acid being most abundant with 24.8±2 and 21.3±1.5 μg g(-1 dry soil in wheat-cotton and wheat-rice rotation, respectively. Two sugars (sucrose, glucose were detected in wheat rhizosheath under both rotations, with highest concentrations of sucrose (4.08±0.5 μg g(-1 and 7.36±1.0 μg g(-1 and glucose (3.12±0.5 μg g(-1 and 3.01± μg g(-1 being detected in rhizosheaths of non-inoculated control plants under both rotations. Diversity of rhizosheath-associated bacteria was evaluated by cultivation, as well as by 454-pyrosequencing of PCR-tagged 16S rRNA gene amplicons. A total of 14 and 12 bacterial isolates predominantly belonging to the genera Arthrobacter, Azospirillum, Bacillus, Enterobacter and Pseudomonaswere obtained from the rhizosheath of wheat grown under wheat-cotton and wheat-rice rotation, respectively. Analysis of pyrosequencing data revealed Proteobacteria, Bacteriodetes and Verrucomicrobia as the most abundant phyla in wheat-rice rotation, whereas Actinobacteria, Firmicutes, Chloroflexi, Acidobacteria, Planctomycetes and Cyanobacteria were predominant in wheat-cotton rotation. From a total of 46,971 sequences, 10.9% showed ≥97% similarity with 16S rRNA genes of 32 genera previously shown to include

  9. 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)

    Cezary Kwiatkowski

    2012-12-01

    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

  10. 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...

  11. Enhancing Soil Productivity Using a Multi-Crop Rotation and Beef Cattle Grazing

    Science.gov (United States)

    Şentürklü, Songül; Landblom, Douglas; Cihacek, Larry; Brevik, Eric

    2016-04-01

    . Crop yields were as follows for the 5 crop years in the study (2011-2015): (1) CC was 0.25, 10.5, 8.03, 1.53, and 7.22t/ha, (2) C silage was 4.08, 9.04, 9.91, 8.65, and 14.4 t/ha, (3) C grain was 1.04, 3.81, 6.09, 3.11, and 5.1 t/ha, (4) SF was 1.10, 1.96, 2.42, 1.31, and 2.29 t/ha, (5) PBY forage was 0.0, 7.68, 11.2, 9.3, and 8.72 t/ha. When cattle grazed annual forage crops (C, PBY, and CC), animal manure and trampling contributed to the overall improvement of soil fertility. These data suggest that the combined effect of a multi-crop rotation that includes animal grazing enhances soil fertility and subsequently crop yields, and animal production for a sustainable integrated agricultural system.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-04-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-04-01

    Progress of twenty projects in the Short Rotation Woody Crops Program is summarized for the period March 1 through May 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 project activities are species screening and genetic selection, stand establishment and cultural treatment, and harvest, collection, transportation, and storage.

  14. Mitigating Groundwater Depletion in North China Plain with Cropping System that Alternate Deep and Shallow Rooted Crops

    Directory of Open Access Journals (Sweden)

    Xiao-Lin Yang

    2017-06-01

    Full Text Available In the North China Plain, groundwater tables have been dropping at unsustainable rates of 1 m per year due to irrigation of a double cropping system of winter wheat and summer maize. To reverse the trend, we examined whether alternative crop rotations could save water. Moisture contents were measured weekly at 20 cm intervals in the top 180 cm of soil as part of a 12-year field experiment with four crop rotations: sweet potato→ cotton→ sweet potato→ winter wheat-summer maize (SpCSpWS, 4-year cycle; peanuts → winter wheat-summer maize (PWS, 2-year cycle; ryegrass–cotton→ peanuts→ winter wheat-summer maize (RCPWS, 3-year cycle; and winter wheat-summer maize (WS, each year. We found that, compared to WS, the SpCSpWS annual evapotranspiration was 28% lower, PWS was 19% lower and RCPWS was 14% lower. The yield per unit of water evaporated improved for wheat within any alternative rotation compared to WS, increasing up to 19%. Average soil moisture contents at the sowing date of wheat in the SpCSpWS, PWS, and RCPWS rotations were 7, 4, and 10% higher than WS, respectively. The advantage of alternative rotations was that a deep rooted crop of winter wheat reaching down to 180 cm followed shallow rooted crops (sweet potato and peanut drawing soil moisture from 0 to 120 cm. They benefited from the sequencing and vertical complementarity of soil moisture extraction. Thus, replacing the traditional crop rotation with cropping system that involves rotating with annual shallow rooted crops is promising for reducing groundwater depletion in the North China Plain.

  15. Crop rotation modelling-A European model intercomparison

    Czech Academy of Sciences Publication Activity Database

    Kollas, C.; Kersebaum, K. C.; Nendel, C.; Manevski, K.; Müller, C.; Palosuo, T.; Armas-Herrera, C.; Beaudoin, N.; Bindi, M.; Charefeddine, M.; Conradt, T.; Constantin, J.; Eitzinger, J.; Ewert, F.; Ferrise, R.; Gaiser, T.; de Cortazar-Atauri, I. G.; Giglio, L.; Hlavinka, Petr; Hoffman, H.; Hofmann, M.; Launay, M.; Manderscheid, R.; Mary, B.; Mirschel, W.; Moriondo, M.; Olesen, J. E.; Öztürk, I.; Pacholski, A.; Ripoche-Wachter, D.; Roggero, P. P.; Roncossek, S.; Rötter, R. P.; Ruget, F.; Sharif, B.; Trnka, Miroslav; Ventrella, D.; Waha, K.; Wegehenkel, M.; Weigel, H-J.; Wu, L.

    2015-01-01

    Roč. 70, oct (2015), s. 98-111 ISSN 1161-0301 Institutional support: RVO:67179843 Keywords : model ensemble * crop simulation models * catch crop * intermediate crop * treatment * Multi-year Subject RIV: GC - Agronomy Impact factor: 3.186, year: 2015

  16. Rotational total skin electron irradiation with a linear accelerator

    Science.gov (United States)

    Evans, Michael D.C.; Devic, Slobodan; Parker, William; Freeman, Carolyn R.; Roberge, David; Podgorsak, Ervin B.

    2008-01-01

    The rotational total skin electron irradiation (RTSEI) technique at our institution has undergone several developments over the past few years. Replacement of the formerly used linear accelerator has prompted many modifications to the previous technique. With the current technique, the patient is treated with a single large field while standing on a rotating platform, at a source‐to‐surface distance of 380 cm. The electron field is produced by a Varian 21EX linear accelerator using the commercially available 6 MeV high dose rate total skin electron mode, along with a custom‐built flattening filter. Ionization chambers, radiochromic film, and MOSFET (metal oxide semiconductor field effect transistor) detectors have been used to determine the dosimetric properties of this technique. Measurements investigating the stationary beam properties, the effects of full rotation, and the dose distributions to a humanoid phantom are reported. The current treatment technique and dose regimen are also described. PACS numbers: 87.55.ne, 87.53.Hv, 87.53.Mr

  17. Comparative acute toxicity of neonicotinoid and pyrethroid insecticides to non-target crayfish (Procambarus clarkii) associated with rice-crayfish crop rotations.

    Science.gov (United States)

    Barbee, Gary C; Stout, Michael J

    2009-11-01

    Most insecticides used to control rice water weevil (Lissorhoptrus oryzophilus Kuscel) infestations are pyrethroids. However, pyrethroids are highly toxic to non-target crayfish associated with rice-crayfish crop rotations. One solution to the near-exclusive reliance on pyrethroids in a rice-crayfish pest management program is to incorporate neonicotinoid insecticides, which are insect specific and effective against weevils but not extremely toxic to crayfish. This study aimed to take the first step to assess neonicotinoids as alternatives to pyrethroids in rice-crayfish crop rotations by measuring the acute toxicities of three candidate neonicotinoid insecticides, clothianidin, dinotefuran and thiamethoxam, to juvenile Procambarus clarkii (Girard) crayfish and comparing them with the acute toxicities of two currently used pyrethroid insecticides, lambda-cyhalothrin and etofenprox. Neonicotinoid insecticides are at least 2-3 orders of magnitude less acutely toxic (96 h LC(50)) than pyrethroids to juvenile Procambarid crayfish: lambda-cyhalothrin (0.16 microg AI L(-1)) = etofenprox (0.29 microg AI L(-1)) > clothianidin (59 microg AI L(-1)) > thiamethoxam (967 microg AI L(-1)) > dinotefuran (2032 microg AI L(-1)). Neonicotinoid insecticides appear to be much less hazardous alternatives to pyrethroids in rice-crayfish crop rotations. Further field-level neonicotinoid acute and chronic toxicity testing with crayfish is needed. (c) 2009 Society of Chemical Industry.

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

    DEFF Research Database (Denmark)

    Li, Xiaoxi; Petersen, Søren O; Sørensen, Peter

    2015-01-01

    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...

  19. Vertical distribution and composition of weed seeds within the plough layer after eleven years of contrasting crop rotation and tillage schemes

    DEFF Research Database (Denmark)

    Scherner, Ananda; Melander, Bo; Kudsk, Per

    2016-01-01

    Tillage methods and crop rotation are probably the two most important cropping factors affecting weed communities, particularly when herbicide use is restricted. This study examined weed dynamics following eleven years of different tillage and crop rotation treatments. The aboveground grass weed...... flora was recorded each year and the content and vertical location of individual weed seeds within the plough layer (0–20 cm) were determined after 11 years of continuous mouldboard ploughing (P), pre-sowing tine cultivation to 8–10 cm soil depth (H8-10) and direct drilling (D). The content of weed...... seeds, especially grass weeds, was determined for three distinct soil layers (0–5, 5–10 and 10–20 cm), reflecting the cultivation depths of the tillage treatments. The annual grass weeds, Apera spica-venti and Vulpia myuros, were promoted by non-inversion tillage and in the case of V. myuros also...

  20. Influence of Conservation Tillage on some Soil Physical Properties and Crop Yield in Vetch-Wheat Rotation in Dryland Cold Region

    Directory of Open Access Journals (Sweden)

    I Eskandari

    2017-10-01

    Full Text Available Introduction Winter wheat is an important, well-adapted grain crop under dryland condition of the northwest of Iran. Soil water is the most limiting resource for crop growth in dryland areas. Therefore, farmers need to use crop residues and minimum tillage to control the soil erosion and effectively store and to use the limited precipitation received for crop production. Crop rotation and tillage system could affect crop yield due to their effects on water conservation and soil chemical and physical properties. Galantini et al., (2000 studied the effect of crop rotation on wheat productivity in the Pampean semi-arid region of Argentina and found that a wheat–vetch (Vicia sativa L. rotation resulted in higher yield and protein content, and greater yield components than the other rotations.Payne et al. (2000 stated that where precipitation amount is marginal (400 mm, dry field pea offers a potential alternative to summer fallowing. The purpose of this study was to identify the optimal tillage system for increasing crop productivity in a vetch–wheat rotation in dryland farming of the northwest of Iran. Materials and Methods The field experiment was carried out from 2010 to 2014 at the Dryland Agricultural Research Station (latitude37° 12´N; longitude 46◦20´E; 1730 m a.s.l., 25 km east of Maragheh, East Azerbaijan Province, Iran. The long-term (10 years average precipitation, temperature and relative humidity of the station are 336.5 mm, 9.4 ◦C and 47.5%, respectively. The soil (Fine Mixed, Mesic, Vertic Calcixerepts, USDA system; Calcisols, FAO system at the study site had a clay loam texture in the 0–15 cm surface layer and a clay texture in the 15–80 cm depth. This study was conducted in vetch (Vicia pannonica- wheat (Triticum aestivum L. rotation. The experiment was arranged in a randomized complete block design with four replications. The tillage treatments consisted of (1 conventional tillage: moldboard plowing followed by one

  1. Effects of rotation of cotton (Gossypium hirsutum L.) and soybean [Glycine max (L.) Merr.] crops on soil fertility in Elizabeth, Mississippi, USA

    OpenAIRE

    H.A., Reddy, K. and Pettigrew, W.T.

    2018-01-01

    The effects of cotton (Gossypium hirsutum L.): soybean [Glycine max (L.) Merr.] rotation on the soil fertility levels are limited. An irrigated soybean: cotton rotation experiment was conducted from 2012 through 2015 near Elizabeth, Mississippi, USA. The crop rotation sequences were included continuous cotton (CCCC), continuous soybean (SSSS), cotton-soybean-cotton-soybean (CSCS), cotton-soybean-soybean-cotton (CSSC), soybean-cotton-cotton-soybean (SCCS), soybean-cotton-soybean-cotton (SCSC)....

  2. Carbon stocks quantification in agricultural systems employing succession and rotation of crops in Rio Grande do Sul State, Brazil.

    Science.gov (United States)

    Walter, Michele K. C.; Marinho, Mara de A.; Denardin, José E.; Zullo, Jurandir, Jr.; Paz-González, Antonio

    2013-04-01

    Soil and vegetation constitute respectively the third and the fourth terrestrial reservoirs of Carbon (C) on Earth. C sequestration in these reservoirs includes the capture of the CO2 from the atmosphere by photosynthesis and its storage as organic C. Consequently, changes in land use and agricultural practices affect directly the emissions of the greenhouse gases and the C sequestration. Several studies have already demonstrated that conservation agriculture, and particularly zero tillage (ZT), has a positive effect on soil C sequestration. The Brazilian federal program ABC (Agriculture of Low Carbon Emission) was conceived to promote agricultural production with environmental protection and represents an instrument to achieve voluntary targets to mitigate emissions or NAMAS (National Appropriated Mitigation Actions). With financial resources of about US 1.0 billion until 2020 the ABC Program has a target of expand ZT in 8 million hectares of land, with reduction of 16 to 20 million of CO2eq. Our objective was to quantify the C stocks in soil, plants and litter of representative grain crops systems under ZT in Rio Grande do Sul State, Brazil. Two treatments of a long term experimental essay (> 20 years) were evaluated: 1) Crop succession with wheat (Triticum aestivum L.)/soybean (Glycine max (L.) Merril); 2) Crop rotation with wheat/soybean (1st year), vetch (Vicia sativa L.)/soybean (2nd year), and white oat (Avena sativa L.)/sorghum (Sorghum bicolor L.) (3rd year). C quantification in plants and in litter was performed using the direct method of biomass quantification. The soil type evaluated was a Humic Rhodic Hapludox, and C quantification was executed employing the method referred by "C mass by unit area". Results showed that soybean plants under crop succession presented greater C stock (4.31MgC ha-1) comparing with soybean plants cultivated under crop rotation (3.59 MgC ha-1). For wheat, however, greater C stock was quantified in plants under rotation

  3. Measuring and partitioning soil respiration in sharkey shrink-swell clays under plantation grown short-rotation woody crops

    Science.gov (United States)

    Wilson G. Hood; Michael C. Tyree; Dylan N. Dillaway Dillaway; Theodor D. Leininger

    2015-01-01

    The Lower Mississippi Alluvial Valley (LMAV) offers an ecological niche for short-rotation woody crop (SRWC) production by mating marginal agricultural land with optimal growing conditions. Approximately 1.7 million ha within the LMAV consist of Sharkey shrink-swell clays. They are considered marginal in terms of traditional agricultural productivity due to their...

  4. Faraday rotation in an electron-positron plasma containing a fraction of ions

    International Nuclear Information System (INIS)

    Hall, J.O.; Shukla, P.K.

    2005-01-01

    The Faraday rotation in a magnetized electron-positron plasma containing a fraction of ions is investigated by using a multifluid description. It is shown that the Faraday rotation for circularly polarized electromagnetic waves with frequencies much larger than the electron/positron plasma and electron gyrofrequencies is proportional to the ion number density and the magnitude of the ambient magnetic-field strength. The results are relevant for astrophysical observations and diagnostics of laboratory electron-positron-ion magnetoplasmas

  5. Observations of rotation in JET plasmas with electron heating by ion cyclotron resonance heating

    DEFF Research Database (Denmark)

    Hellsten, T.; Johnson, T. J.; Van Eester, D.

    2012-01-01

    The rotation of L-mode plasmas in the JET tokamak heated by waves in the ion cyclotron range of frequencies (ICRF) damped on electrons, is reported. The plasma in the core is found to rotate in the counter-current direction with a high shear and in the outer part of the plasma with an almost......, electron absorption of the fast magnetosonic wave by transit time magnetic pumping and electron Landau damping (TTMP/ELD) is the dominating absorption mechanism. Inverted mode conversion is done in (He-3)-H plasmas where the mode converted waves are essentially absorbed by electron Landau damping. Similar...... rotation profiles are seen when heating at the second harmonic cyclotron frequency of He-3 and with mode conversion at high concentrations of He-3. The magnitude of the counter-rotation is found to decrease with an increasing plasma current. The correlation of the rotation with the electron temperature...

  6. Impacts of Rotation Schemes on Ground-Dwelling Beneficial Arthropods.

    Science.gov (United States)

    Dunbar, Mike W; Gassmann, Aaron J; O'Neal, Matthew E

    2016-10-01

    Crop rotation alters agroecosystem diversity temporally, and increasing the number of crops in rotation schemes can increase crop yields and reduce reliance on pesticides. We hypothesized that increasing the number of crops in annual rotation schemes would positively affect ground-dwelling beneficial arthropod communities. During 2012 and 2013, pitfall traps were used to measure activity-density and diversity of ground-dwelling communities within three previously established, long-term crop rotation studies located in Wisconsin and Illinois. Rotation schemes sampled included continuous corn, a 2-yr annual rotation of corn and soybean, and a 3-yr annual rotation of corn, soybean, and wheat. Insects captured were identified to family, and non-insect arthropods were identified to class, order, or family, depending upon the taxa. Beneficial arthropods captured included natural enemies, granivores, and detritivores. The beneficial community from continuous corn plots was significantly more diverse compared with the community in the 2-yr rotation, whereas the community in the 3-yr rotation did not differ from either rotation scheme. The activity-density of the total community and any individual taxa did not differ among rotation schemes in either corn or soybean. Crop species within all three rotation schemes were annual crops, and are associated with agricultural practices that make infield habitat subject to anthropogenic disturbances and temporally unstable. Habitat instability and disturbance can limit the effectiveness and retention of beneficial arthropods, including natural enemies, granivores, and detritivores. Increasing non-crop and perennial species within landscapes in conjunction with more diverse rotation schemes may increase the effect of biological control of pests by natural enemies. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

    Science.gov (United States)

    Felipe G. Sanchez; Mark Coleman; Charles T. Garten; Robert J. Luxmoore; John A. Stanturf; Carl Trettin; Stan D. Wullschleger

    2007-01-01

    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...

  8. Increasing crop diversity mitigates weather variations and improves yield stability.

    Science.gov (United States)

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

    2015-01-01

    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

  9. Performance of spring barley varieties and variety mixtures as affected by manure application and their order in an organic crop rotation

    DEFF Research Database (Denmark)

    Askegaard, Margrethe; Thomsen, Ingrid Kaag; Berntsen, Jørgen

    2011-01-01

    In order to obtain a high and stable yield of organic spring barley, production should be optimized according to the specific environment. To test the performance of spring barley varieties under varying cropping conditions, a field experiment was carried out in 2003 and 2004 in a six-field mixed...... with low manure input than others, variety mixtures that give a robust and stable organic production may potentially be developed....... organic crop rotation. We investigated the choice of variety, the order in a rotation, and the application of manure (slurry and farmyard manure; 0 to 120 total-N ha−1) on grain yields of six selected varieties with different characteristics grown in either pure stands or in two spring barley mixtures...

  10. Economic impacts of short-rotation woody crops for energy or oriented strand board: a Minnesota case study

    Science.gov (United States)

    William F. Lazarus; Douglas G. Tiffany; Ronald S. Zalesny Jr.; Don E. Riemenschneider

    2011-01-01

    Short-rotation woody crops (SRWC) such as hybrid poplars are becoming increasingly competitive with agriculture on marginal land. The trees can be grown for energy and for traditional uses such as oriented strandboard. Using IMPLAN (Impact Analysis for Planning) software, we modeled the impacts of shifting land use from hay and pasture for cow-calf beef operations to...

  11. Welding by using doubly-deflected rotating electron beam

    International Nuclear Information System (INIS)

    Dabek, J.W.; Friedel, K.

    1997-01-01

    The paper presents the welding process by using double-deflected rotating electron beam, as a method to obtain good quality welds. It is shown possible variants of work of modified beam, principles of creation, process control and results of welding. Comparison of quality welds obtained by using traditional and modified electron beams is made too. (author). 11 refs, 8 figs

  12. Water Quality Changes in a Short-Rotation Woody Crop Riparian Buffer

    Science.gov (United States)

    Rosa, D.; Clausen, J.; Kuzovkina, J.

    2016-12-01

    Converting riparian buffers in agricultural areas from annual row crops to short rotation woody crops (SRWCs) grown for biofuel can provide both water quality benefits and a financial incentive for buffer adoption among agricultural producers. A randomized complete block design was used to determine water quality changes resulting from converting plots previously cultivated in corn to SRWC willow (Salix. spp) adjacent to a stream in Storrs, CT. Both overland flow and ground water samples were analyzed for total nitrogen (TN), nitrate + nitrite (NO2+NO3-N), and total phosphorus (TP). Overland flow was also analyzed for suspended solids concentration (SSC). Lower (p = 0.05) concentrations of TN (56%) and TP (61%) were observed in post-coppice surface runoff from willow plots than from corn plots. Shallow ground water concentrations at the edge of willow plots were lower in TN (56%) and NO3+NO2-N (64%), but 35% higher in TP, than at the edge of corn plots. SSC was also lower (72%) in overland flow associated with willow compared to corn. The treatment had no effect on discharge or mass export. These results suggest conversion from corn to a SRWC in a riparian area can provide water quality benefits similar to those observed in restored and established buffers.

  13. Rotatable spin-polarized electron source for inverse-photoemission experiments

    International Nuclear Information System (INIS)

    Stolwijk, S. D.; Wortelen, H.; Schmidt, A. B.; Donath, M.

    2014-01-01

    We present a ROtatable Spin-polarized Electron source (ROSE) for the use in spin- and angle-resolved inverse-photoemission (SR-IPE) experiments. A key feature of the ROSE is a variable direction of the transversal electron beam polarization. As a result, the inverse-photoemission experiment becomes sensitive to two orthogonal in-plane polarization directions, and, for nonnormal electron incidence, to the out-of-plane polarization component. We characterize the ROSE and test its performance on the basis of SR-IPE experiments. Measurements on magnetized Ni films on W(110) serve as a reference to demonstrate the variable spin sensitivity. Moreover, investigations of the unoccupied spin-dependent surface electronic structure of Tl/Si(111) highlight the capability to analyze complex phenomena like spin rotations in momentum space. Essentially, the ROSE opens the way to further studies on complex spin-dependent effects in the field of surface magnetism and spin-orbit interaction at surfaces

  14. Initial vibrational and rotational yields from subexcitation electrons in molecular hydrogen

    International Nuclear Information System (INIS)

    Douthat, D.A.

    1987-01-01

    As the energy of a single source electron injected into a molecular gas is degraded through collisions, initial products include secondary electrons, ions, and excited molecules. Electrons with kinetic energies less than the minimum required for excitation of the lowest electronic state are given the designation subexcitation electrons. These electrons are still capable of exciting vibrational and rotational states of molecular gases. In this calculation, the initial numbers of vibrational and rotational excitations (yields) produced as the subexcitation electrons undergo further energy degradation are determined for molecular hydrogen. The calculation requires a complete set of cross section data for numerical solution of the Boltzmann equation. The initial energy distribution of electrons is taken to be the subexcitation distribution which was determined previously. The initial yields are tabulated for gas temperatures from 50 K to 1500 K for a source electron with initial energy 10 keV. 26 references

  15. Simulation of electron beam from two strip electron guns and control of power density by rotation of gun

    International Nuclear Information System (INIS)

    Sahu, G K; Baruah, S; Thakur, K B

    2012-01-01

    Electron beam is preferably used for large scale evaporation of refractory materials. Material evaporation from a long and narrow source providing a well collimated wedge shaped atomic beam has applications in isotopic purification of metals relevant to nuclear industry. The electron beam from an electron gun with strip type filament provides a linear heating source. However, the high power density of the electron beam can lead to turbulence of the melt pool and undesirable splashing of molten metal. For obtaining quiet surface evaporation, the linear electron beam is generally scanned along its length. To further reduce the power density to maintain quiet evaporation the width of the vapour source can be controlled by rotating the electron gun on its plane, thereby scanning an inclined beam over the molten pool. The rotation of gun has further advantages. When multiple strip type electron guns are used for scaling up evaporation length, a dark zone appears between two beams due to physical separation of adjacent guns. This dark zone can be reduced by rotating the gun and thereby bringing two adjacent beams closer. The paper presented here provides the simulation results of the electron beam trajectory and incident power density originating from two strip electron guns by using in-house developed code. The effect of electron gun rotation on the electron beam trajectory and power density is studied. The simulation result is experimentally verified with the image of molten pool and heat affected zone taken after experiment. This technique can be gainfully utilized in controlling the time averaged power density of the electron beam and obtaining quiet evaporation from the metal molten pool.

  16. Energy crops for biogas plants. Bavaria; Energiepflanzen fuer Biogasanlagen. Bayern

    Energy Technology Data Exchange (ETDEWEB)

    Aigner, A.; Biertuempel, A.; Conrad, M. (and others)

    2012-08-15

    For agriculturists in Bavaria (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.

  17. Growth and yield of cowpea/sunflower crop rotation under different irrigation management strategies with saline water

    Directory of Open Access Journals (Sweden)

    Antônia Leila Rocha Neves

    2015-05-01

    Full Text Available This study aimed to evaluate the effect of management strategies of irrigation with saline water on growth and yield of cowpea and sunflower in a crop rotation. The experiment was conducted in randomized blocks with thirteen treatments and five replications. The treatments consisted of: T1 (control, T2, T3 and T4 using water of 0.5 (A1, 2.2 (A2, 3.6 (A3 and 5.0 (A4 dS m-1, respectively, during the entire crop cycle; T5, T6 and T7, use of A2, A3 and A4 water, respectively, only in the flowering and fructification stage of the crop cycle; using different water in a cyclic way, six irrigations with A1 followed by six irrigations with A2 (T8, A3 (T9 and A4, (T10, respectively; T11, T12 and T13, using water A2, A3 and A4, respectively, starting at 11 days after planting (DAP and continuing until the end of the crop cycle. These treatments were employed in the first crop (cowpea, during the dry season, and the same plots were used for the cultivation of sunflower as succeeding crop during rainy season. The strategies of use of saline water in the salt tolerant growth stage (treatments T5, T6 and T7 or cyclically (treatments T8, T9 and T10 reduced the amount of good quality water used in the production of cowpea by 34 and 47%, respectively, without negative impacts on crop yield, and did not show the residual effects of salinity on sunflower as a succeeding crop. Thus, these strategies appear promising to be employed in areas with water salinity problems in the semiarid region of Brazil.

  18. A methodological approach for deriving regional crop rotations as basis for the assessment of the impact of agricultural strategies using soil erosion as example.

    Science.gov (United States)

    Lorenz, Marco; Fürst, Christine; Thiel, Enrico

    2013-09-01

    Regarding increasing pressures by global societal and climate change, the assessment of the impact of land use and land management practices on land degradation and the related decrease in sustainable provision of ecosystem services gains increasing interest. Existing approaches to assess agricultural practices focus on the assessment of single crops or statistical data because spatially explicit information on practically applied crop rotations is mostly not available. This provokes considerable uncertainties in crop production models as regional specifics have to be neglected or cannot be considered in an appropriate way. In a case study in Saxony, we developed an approach to (i) derive representative regional crop rotations by combining different data sources and expert knowledge. This includes the integration of innovative crop sequences related to bio-energy production or organic farming and different soil tillage, soil management and soil protection techniques. Furthermore, (ii) we developed a regionalization approach for transferring crop rotations and related soil management strategies on the basis of statistical data and spatially explicit data taken from so called field blocks. These field blocks are the smallest spatial entity for which agricultural practices must be reported to apply for agricultural funding within the frame of the European Agricultural Fund for Rural Development (EAFRD) program. The information was finally integrated into the spatial decision support tool GISCAME to assess and visualize in spatially explicit manner the impact of alternative agricultural land use strategies on soil erosion risk and ecosystem services provision. Objective of this paper is to present the approach how to create spatially explicit information on agricultural management practices for a study area around Dresden, the capital of the German Federal State Saxony. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Heck, Richard; Deen, Bill

    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...

  20. Allelopathy in agroecosystems: Wheat phytotoxicity and its possible roles in crop rotation.

    Science.gov (United States)

    Lodhi, M A; Bilal, R; Malik, K A

    1987-08-01

    The germination rates of cotton and wheat seeds were significantly affected by various extracts of wheat mulch and soils collected from the wheat field. This toxicity was even more pronounced against seedling growth. Five allelochemics: ferulic,p-coumaric,p-OH benzoic, syringic, and vanillic acids, were identified from the wheat mulch and its associated soil. Quantitatively, ferulic acid was found at higher concentrations thanp-coumaric acid in the soil. Various concentrations of ferulic andp-coumaric acids were toxic to the growth of radish in a bioassay. The functional aspects of allelochemic transfer from decaying residue to soil and the subsequent microbial degradation within agroecosystems are discussed, particularly as they relate to wheat crop rotation, with wheat and cotton, in Pakistan.

  1. Modeling impacts of water and fertilizer management on the ecosystem service of rice rotated cropping system in China

    Science.gov (United States)

    Chen, H.; Yu, C.; Li, C.

    2015-12-01

    Sustainable agricultural intensification demand optimum resource managements of agro-ecosystems. Detailed information on the impacts of water use and nutrient application on agro-ecosystem services including crop yields, greenhouse gas (GHG) emissions and nitrogen (N) loss is the key to guide field managements. In this study, we use the DeNitrification-DeComposition (DNDC) model to simulate the biogeochemical processes for rice rotated cropping systems in China. We set varied scenarios of water use in more than 1600 counties, and derived optimal rates of N application for each county in accordance to water use scenarios. Our results suggest that 0.88 ± 0.33 Tg per year (mean ± standard deviation) of synthetic N could be reduced without reducing rice yields, which accounts for 15.7 ± 5.9% of current N application in China. Field managements with shallow flooding and optimal N applications could enhance ecosystem services on a national scale, leading to 34.3% reduction of GHG emissions (CH4, N2O, and CO2), 2.8% reduction of overall N loss (NH3 volatilization, denitrification and N leaching) and 1.7% increase of rice yields, as compared to current management conditions. Among provinces with major rice production, Jiangsu, Yunnan, Guizhou, and Hubei could achieve more than 40% reduction of GHG emissions under appropriate water managements, while Zhejiang, Guangdong, and Fujian could reduce more than 30% N loss with optimal N applications. Our modeling efforts suggest that China is likely to benefit from reforming water and fertilization managements for rice rotated cropping system in terms of sustainable crop yields, GHG emission mitigation and N loss reduction, and the reformation should be prioritized in the above-mentioned provinces. Keywords: water regime, nitrogen fertilization, sustainable management, ecological modeling, DNDC

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-15

    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.

  3. Energy crops for biogas plants. Baden-Wuerttemberg; Energiepflanzen fuer Biogasanlagen. Baden-Wuerttemberg

    Energy Technology Data Exchange (ETDEWEB)

    Butz, A.; Heiermann, M.; Herrmann, C. [and others

    2013-05-01

    For agriculturists in Baden-Wuerttemberg (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.

  4. The effect of cover crop and crop rotation on soil water storage and on sorghum yield Efeito de cultura de cobertura e de rotação de cultura no armazenamento de água do solo e no rendimento de sorgo

    Directory of Open Access Journals (Sweden)

    Demóstenes Marcos Pedrosa de Azevedo

    1999-03-01

    Full Text Available Crop rotation and cover crop can be important means for enhancing crop yield in rainfed areas such as the lower Coastal Bend Region of Texas, USA. A trial was conducted in 1995 as part of a long-term cropping experiment (7 years to investigate the effect of oat (Avena sativa L. cover and rotation on soil water storage and yield of sorghum (Sorghum bicolor L.. The trial design was a RCB in a split-plot arrangement with four replicates. Rotation sequences were the main plots and oat cover crop the subplots. Cover crop reduced sorghum grain yield. This effect was attributed to a reduced concentration of available soil N and less soil water storage under this treatment. By delaying cover termination, the residue with a high C/N acted as an N sink through competition and/or immobilization instead of an N source to sorghum plants. Crop rotation had a significantly positive effect on sorghum yield and this effect was attributed to a significantly larger amount of N concentration under these rotation sequences.Rotação de cultura e cultura de cobertura constituem importantes meios para melhoria do rendimento de culturas em áreas de sequeiro como a região "Coastal Bend" do Estado do Texas. Um ensaio foi conduzido em 1995, como parte de um experimento de longa duração (7 anos, com o objetivo de investigar o efeito da aveia (Avena sativa L. como cultura de cobertura, e da rotação de cultura, no armazenamento da água do solo e no rendimento do sorgo (Sorghum bicolor L.. O delineamento experimental adotado foi o de blocos ao acaso, em parcelas subdivididas, com quatro repetições. As rotações foram alocadas nas parcelas, e a cultura de cobertura, nas subparcelas. A cultura de cobertura reduziu o rendimento do sorgo. Este efeito foi atribuído à reduzida concentração de N disponível do solo. Por atraso no extermínio e incorporação da aveia, seu resíduo, com elevada relação C/N, atuou como dreno, pela imobilização, em lugar de ser fonte

  5. A spatial ecology study on the effects of field conditions and crop rotation on the incidence of Plectris aliena (Coleoptera: Scarabaeidae) grub damage to sweetpotato roots.

    Science.gov (United States)

    Brill, Nancy L; Osborne, Jason; Abney, Mark R

    2013-10-01

    A farmscape study was conducted in commercial sweetpotato (Ipomoea batatas (L.) Lam) fields in Columbus County, NC, in 2010 and 2011 to investigate the effects of the following field conditions: soil drainage class, soil texture, field size, border habitat, land elevation, and the previous year's crop rotation on the incidence of damage caused by Plectris aliena Chapman (Coleoptera:Scarabaeidae) larval feeding. Soil drainage and crop rotation significantly affected the incidence of damage to roots, with well drained soils having a low estimated incidence of damaged roots (0.004) compared with all other drainage classes (0.009-0.011 incidence of damaged roots). Fields with soybeans [Glycine max (L.) Merr] planted the preceding year had the highest incidence of root damage (0.15) compared with all other crops. The effects of border habitats, which were adjacent to grower fields where roots were sampled, showed that as the location of the roots was closer to borders of soybean (planted the year before) or grass fields, the chance of damage to roots decreased. Results indicate that growers can use crop rotation as a management technique and avoid planting sweetpotatoes the year after soybeans to reduce the incidence of P. aliena larval feeding on sweetpotato roots. Environmental conditions such as fields with poor drainage and certain border habitats may be avoided, or selected, by growers to reduce risk of damage to roots by P. aliena.

  6. Nonadiabatic Response Model of Laser-Induced Ultrafast π-Electron Rotations in Chiral Aromatic Molecules

    International Nuclear Information System (INIS)

    Kanno, Manabu; Kono, Hirohiko; Fujimura, Yuichi; Lin, Sheng H.

    2010-01-01

    We theoretically investigated the nonadiabatic couplings between optically induced π-electron rotations and molecular vibrations in a chiral aromatic molecule irradiated by a nonhelical, linearly polarized laser pulse. The results of wave packet dynamics simulation show that the vibrational amplitudes strongly depend on the initial rotation direction, clockwise or counterclockwise, which is controlled by the polarization direction of the incident pulse. This suggests that attosecond π-electron rotations can be observed by spectroscopic detection of femtosecond molecular vibrations.

  7. Modeling impacts of water and fertilizer management on ecosystem services from rice rotated crop systems in China

    Science.gov (United States)

    Chen, Han; Yu, Chaoqing; Li, Changsheng; Huang, Xiao; Zhang, Jie; Yue, Yali; Huang, Guorui

    2015-04-01

    Sustainable intensification in agriculture has stressed the need for management practices that could increase crop yields while simultaneously reducing environmental impacts. It is well recognized that water and nutrient management hold great promise to address these goals. This study uses the DNDC biogeochemical model to stimulate the impacts of water regime and nitrogen fertilizer management interactions on ecosystem services of rice rotated crop systems in China. County-level optimal nitrogen fertilizer application rates under various water management practices were captured and then multiple scenarios of water and nitrogen fertilizer management were set to more than 1600 counties with rice rotations in China. Results indicate that an national average of 15.7±5.9% (the mean value and standard deviation derive from variability of three water management practices) reduction of nitrogen fertilizer inputs can be achieved without significantly sacrificing rice yields. On a national scale, shallow flooding with optimal N application rates appear most potential to enhance ecosystem services, which led to 10.6% reduction of nitrogen fertilizer inputs, 34.3% decrease of total GHG emissions, 2.8% less of overall N loss (NH3 volatilization, denitrification and N leaching) and a 1.7% increase of rice yields compared to the baseline scenario. Regional GHG emissions mitigation derived from water regime change vary with soil properties and the multiple crop index. Among the main production regions of rice in China, the highest reduction happened in Jiangxu, Yunnan, Guizhou and Hubei (more than 40% reduction) with high SOC, high multiple crop index and low clay fraction. The highest reduction of GHG emissions derived from reducing current N application rate to optimal rate appeared in Zhejiang, Guangdong, Jiangsu where the serious over-application of mineral N exit. It was concluded that process models like DNDC would act an essential tool to identify sustainable agricultural

  8. Danish farmer’s perception of GM-crops

    DEFF Research Database (Denmark)

    Søndergaard, Janus; Pedersen, Søren Marcus; Gylling, Morten

    2005-01-01

    This paper presents a study of 185 farmer’s perception of GM-crops in Denmark. The respondent’s attitude to GM-crops mainly reflects a conservative view of the adoption of GM-crops. Among farmers only the exciting crops in rotation is seen as their future potential GM-crops. Findings from...

  9. Rotational and fine structure of open-shell molecules in nearly degenerate electronic states

    Science.gov (United States)

    Liu, Jinjun

    2018-03-01

    An effective Hamiltonian without symmetry restriction has been developed to model the rotational and fine structure of two nearly degenerate electronic states of an open-shell molecule. In addition to the rotational Hamiltonian for an asymmetric top, this spectroscopic model includes the energy separation between the two states due to difference potential and zero-point energy difference, as well as the spin-orbit (SO), Coriolis, and electron spin-molecular rotation (SR) interactions. Hamiltonian matrices are computed using orbitally and fully symmetrized case (a) and case (b) basis sets. Intensity formulae and selection rules for rotational transitions between a pair of nearly degenerate states and a nondegenerate state have also been derived using all four basis sets. It is demonstrated using real examples of free radicals that the fine structure of a single electronic state can be simulated with either a SR tensor or a combination of SO and Coriolis constants. The related molecular constants can be determined precisely only when all interacting levels are simulated simultaneously. The present study suggests that analysis of rotational and fine structure can provide quantitative insights into vibronic interactions and related effects.

  10. Crop residues as driver for N2O emissions from a sandy loam soil

    DEFF Research Database (Denmark)

    Pugesgaard, Siri; Petersen, Søren O.; Chirinda, Ngonidzashe

    2017-01-01

    -term experiment on a loamy sand soil at Foulum in Denmark. All cropping systems included winter wheat, a leguminous crop (faba bean or grass-clover), potato and spring barley grown in different 4-crop rotations varying in strategies for N supply (fertilizer/manure type and rate, use of catch crops and green......-N leaching losses ranged from 39 to 56 kg N ha−1 y−1 and were lowest in rotations with catch crops; leaching was not correlated with N surplus or N input in fertilizer or manure. Crop yields of the organic rotations were 25 to 37% lower than in identical conventional rotations. As a consequence, yield...

  11. 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)

    Guillermo Adrián Divito

    2010-07-01

    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

  12. Effect of a 5-Year Multi-Crop Rotation on Mineral N and Hard Red Spring Wheat Yield, Protein, Test Weight and Economics in Western North Dakota, USA

    Science.gov (United States)

    Landblom, Douglas; Senturklu, Songul; Cihacek, Larry; Brevik, Eric

    2016-04-01

    The objectives of this non-irrigated cropping study was to employ the principles of soil health and determine the effect of rotation on seasonal mineral N, HRSW production, protein, test weight, and economics. Prior to the initiation of this research, the cropping study area had been previously seeded to hard red spring wheat (HRSW). The cropping systems consisted of a continuous HRSW control (C) compared to HRSW grown in a multi-crop 5-year rotation (R). The 5-yr rotation consisted of HRSW, cover crop (dual crop winter triticale-hairy vetch harvested for hay in June and immediately reseeded to a 7-species cover crop mix grazed by cows after weaning from mid-November to mid-December), forage corn, field pea-forage barley, and sunflower. The cereal grains, cover crops, and pea-barley intercrop were seeded using a JD 1590 no-till drill, 19 cm row spacing, and seed depth of 2.54 cm Cereal grain plant population was 3,088,750 plants/ha. The row crops were planted using a JD 7000 no-till planter, 76.2 cm row spacing, and seed depth of 5.08 cm. Plant population for the row crops was 46,947 plants/ha. Weeds were controlled using a pre-plant burn down and post-emergence control except for cover crops and pea-barley where a pre-plant burn down was the only chemical applied. Fertilizer application was based on soil test results and recommendations from the North Dakota State University Soil Testing Laboratory. During the 1st three years of the study 31.8 kg of N was applied to the C HRSW and then none the last two years of the 5-year period. The R HRSW was fertilized with 13.6 kg of N the 1st two years of the study and none the remaining three years of the 5-year period. However, chloride was low; therefore, 40.7-56.1 kg/ha were applied each year to both the C and R treatments. Based on 2014 and 2015 seasonal mineral N values, the data suggests that N levels were adequate to meet the 2690 kg/ha yield goal. In 2015, however, the R yield goal was exceeded by 673 kg/ha whereas

  13. 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)

    Thorup-Kristensen, Kristian; Dresbøll, Dorte Bodin; Kristensen, Hanne Lakkenborg

    2012-01-01

    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...... of the organic rotation, both relying on green manures and catch crops grown during the autumn after the main crop 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...... 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...

  14. Grassland-Cropping Rotations: An Avenue for Agricultural Diversification to Reconcile High Production with Environmental Quality.

    Science.gov (United States)

    Lemaire, Gilles; Gastal, François; Franzluebbers, Alan; Chabbi, Abad

    2015-11-01

    A need to increase agricultural production across the world to ensure continued food security appears to be at odds with the urgency to reduce the negative environmental impacts of intensive agriculture. Around the world, intensification has been associated with massive simplification and uniformity at all levels of organization, i.e., field, farm, landscape, and region. Therefore, we postulate that negative environmental impacts of modern agriculture are due more to production simplification than to inherent characteristics of agricultural productivity. Thus by enhancing diversity within agricultural systems, it should be possible to reconcile high quantity and quality of food production with environmental quality. Intensification of livestock and cropping systems separately within different specialized regions inevitably leads to unacceptable environmental impacts because of the overly uniform land use system in intensive cereal areas and excessive N-P loads in intensive animal areas. The capacity of grassland ecosystems to couple C and N cycles through microbial-soil-plant interactions as a way for mitigating the environmental impacts of intensive arable cropping system was analyzed in different management options: grazing, cutting, and ley duration, in order to minimize trade-offs between production and the environment. We suggest that integrated crop-livestock systems are an appropriate strategy to enhance diversity. Sod-based rotations can temporally and spatially capture the benefits of leys for minimizing environmental impacts, while still maintaining periods and areas of intensive cropping. Long-term experimental results illustrate the potential of such systems to sequester C in soil and to reduce and control N emissions to the atmosphere and hydrosphere.

  15. Effects of Monoculture, Crop Rotation, and Soil Moisture Content on Selected Soil Physicochemical and Microbial Parameters in Wheat Fields

    Directory of Open Access Journals (Sweden)

    A. Marais

    2012-01-01

    Full Text Available Different plants are known to have different soil microbial communities associated with them. Agricultural management practices such as fertiliser and pesticide addition, crop rotation, and grazing animals can lead to different microbial communities in the associated agricultural soils. Soil dilution plates, most-probable-number (MPN, community level physiological profiling (CLPP, and buried slide technique as well as some measured soil physicochemical parameters were used to determine changes during the growing season in the ecosystem profile in wheat fields subjected to wheat monoculture or wheat in annual rotation with medic/clover pasture. Statistical analyses showed that soil moisture had an over-riding effect on seasonal fluctuations in soil physicochemical and microbial populations. While within season soil microbial activity could be differentiated between wheat fields under rotational and monoculture management, these differences were not significant.

  16. Influence of Previous Crop on Durum Wheat Yield and Yield Stability in a Long-term Experiment

    Directory of Open Access Journals (Sweden)

    Anna Maria Stellacci

    2011-02-01

    Full Text Available Long-term experiments are leading indicators of sustainability and serve as an early warning system to detect problems that may compromise future productivity. So the stability of yield is an important parameter to be considered when judging the value of a cropping system relative to others. In a long-term rotation experiment set up in 1972 the influence of different crop sequences on the yields and on yield stability of durum wheat (Triticum durum Desf. was studied. The complete field experiment is a split-split plot in a randomized complete block design with two replications; the whole experiment considers three crop sequences: 1 three-year crop rotation: sugar-beet, wheat + catch crop, wheat; 2 one-year crop rotation: wheat + catch crop; 3 wheat continuous crop; the split treatments are two different crop residue managements; the split-split plot treatments are 18 different fertilization formulas. Each phase of every crop rotation occurred every year. In this paper only one crop residue management and only one fertilization treatment have been analized. Wheat crops in different rotations are coded as follows: F1: wheat after sugar-beet in three-year crop rotation; F2: wheat after wheat in three-year crop rotation; Fc+i: wheat in wheat + catch crop rotation; Fc: continuous wheat. The following two variables were analysed: grain yield and hectolitre weight. Repeated measures analyses of variance and stability analyses have been perfomed for the two variables. The stability analysis was conducted using: three variance methods, namely the coefficient of variability of Francis and Kannenberg, the ecovalence index of Wricke and the stability variance index of Shukla; the regression method of Eberhart and Russell; a method, proposed by Piepho, that computes the probability of one system outperforming another system. It has turned out that each of the stability methods used has enriched of information the simple variance analysis. The Piepho

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-15

    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.

  18. Winter cover crop effect on corn seedling pathogens

    Science.gov (United States)

    Cover crops are an excellent management tool to improve the sustainability of agriculture. Winter rye cover crops have been used successfully in Iowa corn-soybean rotations. Unfortunately, winter rye cover crops occasionally reduce yields of the following corn crop. We hypothesize that one potential...

  19. Yields of crops on a rhodic ferralsol in southern Brazil in relation to ...

    African Journals Online (AJOL)

    Even though no-tillage, crop rotation management systems have been accepted as useful for sustaining crop production, there is the need to identify which crops can be used for such rotations. This study evaluated the dry matter and grain yields of eight winter and two summer crops (maize, Zea mays L. and soybean, ...

  20. Impacts on Water Management and Crop Production of Regional Cropping System Adaptation to Climate Change

    Science.gov (United States)

    Zhong, H.; Sun, L.; Tian, Z.; Liang, Z.; Fischer, G.

    2014-12-01

    China is one of the most populous and fast developing countries, also faces a great pressure on grain production and food security. Multi-cropping system is widely applied in China to fully utilize agro-climatic resources and increase land productivity. As the heat resource keep improving under climate warming, multi-cropping system will also shifting northward, and benefit crop production. But water shortage in North China Plain will constrain the adoption of new multi-cropping system. Effectiveness of multi-cropping system adaptation to climate change will greatly depend on future hydrological change and agriculture water management. So it is necessary to quantitatively express the water demand of different multi-cropping systems under climate change. In this paper, we proposed an integrated climate-cropping system-crops adaptation framework, and specifically focused on: 1) precipitation and hydrological change under future climate change in China; 2) the best multi-cropping system and correspondent crop rotation sequence, and water demand under future agro-climatic resources; 3) attainable crop production with water constraint; and 4) future water management. In order to obtain climate projection and precipitation distribution, global climate change scenario from HADCAM3 is downscaled with regional climate model (PRECIS), historical climate data (1960-1990) was interpolated from more than 700 meteorological observation stations. The regional Agro-ecological Zone (AEZ) model is applied to simulate the best multi-cropping system and crop rotation sequence under projected climate change scenario. Finally, we use the site process-based DSSAT model to estimate attainable crop production and the water deficiency. Our findings indicate that annual land productivity may increase and China can gain benefit from climate change if multi-cropping system would be adopted. This study provides a macro-scale view of agriculture adaptation, and gives suggestions to national

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

    DEFF Research Database (Denmark)

    Acharya, Bharat Sharma; Rasmussen, Jim; Eriksen, Jørgen

    2012-01-01

    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...... 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...

  2. Poloidal rotation driven by electron cyclotron resonance wave in tokamak plasmas

    Directory of Open Access Journals (Sweden)

    Qing Zhou

    2017-10-01

    Full Text Available The poloidal electric filed, which is the drive field of poloidal rotation, has been observed and increases obviously after the injection of electron cyclotron resonance wave in HL-2A experiment, and the amplitude of the poloidal electric field is in the order of 103 V/m. Through theoretical analysis using Stringer rotation model, the observed poloidal electric field is of the same order as the theoretical calculation value. In addition, the magnetic pump damping which would damp the poloidal rotation is calculated numerically and the calculation results show that the closer to the core plasmas, the stronger the magnetic pump damping will be. Meanwhile, according to the value of the calculated magnetic pump damping, the threshold of the poloidal electric field which could overcome magnetic pump damping and drive poloidal rotation in tokamak plasmas is given out. Finally, the poloidal rotation velocity over time at different minor radius is studied theoretically.

  3. Thermochemical and physical evaluation of poplar genotypes as short rotation forestry crops for energy use

    International Nuclear Information System (INIS)

    Monedero, Esperanza; Hernández, Juan José; Cañellas, Isabel; Otero, Jose María; Sixto, Hortensia

    2016-01-01

    Highlights: • The combustion properties of poplar genotypes harvested from three different sites were analyzed. • Both the genotype and the locations affect the expected combustion behavior. • Among the poplar genotypes, ‘Monviso’ and ‘Viriato’ are expected to have better combustion behavior. • No operating problems derived from fouling/corrosion are expected for any of the genotypes. - Abstract: Short rotation plantations of fast-growing species provide a promising way to produce heat and electricity from renewable sources. The thermo-chemical and physical properties of different genotypes of poplar in short rotation forestry crops grown at three locations with different climatic and edaphic characteristics as well as planting density, have been determined in order to characterize the most appropriate biomass in terms of energy potential. The planting density was 6666 or 13,333 trees/ha (depending on the location) in a rotation of three-four years and the analysis was carried out at the end of the first rotation. For all the genotypes, experimental tests to quantify the moisture content, particle size distribution, bulk density, heating value, ash content and composition as well as the volatile matter were performed. In addition, natural air drying of biomass (stem and branches) was studied in two locations with the aim of determining the humidity loss during raw storage. A significant effect of the genotype and the planting density on the biomass properties was observed. The results obtained indicate that ‘Monviso’ and ‘Viriato’ are the most suitable genotypes. No operational problems related to ash fouling and deposition in combustion devices are expected for any of the genotypes studied.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    -year crop rotations including various cash crops and grass-clover leys; two rotations running during the first two courses with the one replaced with another rotation during the last course. The rotations were combined with four combinations of the treatments; with and without animal manure (‘without...

  5. Nitrate leaching from organic and conventional crop production farms

    OpenAIRE

    Olesen, J.E.; Berntsen, J.; Petersen, B.M.; Kristensen, I.S.

    2004-01-01

    Farm accounting data from the Institute of Food Economics and from Central Agricultural Registers in Denmark were used to define the import of nitrogen (N) to farmed fields on conventional and organic arable farms to 129 and 51 kg N ha-1 yr-1, respectively. Based on the recorded distribution of crops, a generalised crop rotation was defined for each of the two farming systems. The crop rotation for the organic farm had a high share of spring cereals and additionally 20% grass-clover in the ro...

  6. Development and Deployment of a Short Rotation Woody Crops Harvesting System Based on a Case New Holland Forage Harvester and SRC Woody Crop Header

    Energy Technology Data Exchange (ETDEWEB)

    Eisenbies, Mark [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Volk, Timothy [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Abrahamson, Lawrence [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Shuren, Richard [GreenWood Resources, Inc., Portland, OR (United States); Stanton, Brian [GreenWood Resources, Inc., Portland, OR (United States); Posselius, John [Case New Holland, New Holland, PA (United States); McArdle, Matt [Mesa Reduction Engineering and Processing, Inc., Auburn, NY (United States); Karapetyan, Samvel [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Patel, Aayushi [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Shi, Shun [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States); Zerpa, Jose [State Univ. of New York College of Environmental Science and Forestry (SUNY-ESF), Syracuse, NY (United States)

    2014-10-03

    Biomass for biofuels, bioproducts and bioenergy can be sourced from forests, agricultural crops, various residue streams, and dedicated woody or herbaceous crops. Short rotation woody crops (SRWC), like willow and hybrid poplar, are perennial cropping systems that produce a number of environmental and economic development benefits in addition to being a renewable source of biomass that can be produced on marginal land. Both hybrid poplar and willow have several characteristics that make them an ideal feedstock for biofuels, bioproducts, and bioenergy; these include high yields that can be obtained in three to four years, ease of cultivar propagation from dormant cuttings, a broad underutilized genetic base, ease of breeding, ability to resprout after multiple harvests, and feedstock composition similar to other sources of woody biomass. Despite the range of benefits associated with SRWC systems, their deployment has been restricted by high costs, low market acceptance associated with inconsistent chip quality (see below for further explanation), and misperceptions about other feedstock characteristics (see below for further explanation). Harvesting of SRWC is the largest single cost factor (~1/3 of the final delivered cost) in the feedstock supply system. Harvesting is also the second largest input of primary fossil energy in the system after commercial N fertilizer, accounting for about one third of the input. Therefore, improving the efficiency of the harvesting system has the potential to reduce both cost and environmental impact. At the start of this project, we projected that improving the overall efficiency of the harvesting system by 25% would reduce the delivered cost of SRWC by approximately $0.50/MMBtu (or about $7.50/dry ton). This goal was exceeded over the duration of this project, as noted below.

  7. Improvement of red pepper yield and soil environment by summer catch aquatic crops in greenhouses

    Science.gov (United States)

    Du, X. F.; Wang, L. Z.; Peng, J.; Wang, G. L.; Guo, X. S.; Wen, T. G.; Gu, D. L.; Wang, W. Z.; Wu, C. W.

    2016-08-01

    To investigate effects of the rotation of summer catch crops on remediation retrogressed soils in continuous cropping, a field experiment was conducted. Rice, water spinach, or cress were selected as summer catch crops; bare fallow during summer fallow was used as the control group. Results showed that aquatic crops grown in summer fallow period could effectively reduce soil bulk density and pH, facilitate soil nutrient release, and improve soil physical and chemical properties compared with those grown in fallow period. Paddy-upland rotation could improve soil microbial members and increase bacterial and actinomycete populations; by contrast, paddy-upland rotation could reduce fungal populations and enhance bacterium-to-fungus ratio. Paddy-upland rotation could also actively promote activities of soil enzymes, such as urease, phosphatase, invertase, and catalase. The proposed paddy-upland rotation significantly affected the growth of red pepper; the yield and quality of the grown red pepper were enhanced. Summer catch crops, such as rice, water spinach, and cress significantly increased pepper yield in the following growing season by 15.4%, 10.2% and 14.0%, respectively, compared with those grown in fallow treatment. Therefore, the proposed paddy-upland crop rotation could be a useful method to alleviate continuous cropping problems involved in cultivating red pepper in greenhouses.

  8. Influence of cover crops on arthropods, free-living nematodes, and yield in a succeeding no-till soybean crop

    Science.gov (United States)

    Production practices that incorporate fall-planted cover crops into no-till agronomic crop rotations have become increasingly popular across the Northeastern United States for weed suppression and enhancing environmental stewardship. Field experiments were conducted in 2011 and 2012 to investigate e...

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

    International Nuclear Information System (INIS)

    Jitareanu, G.; Ailincai, C.; Bucur, D.; Raus, L.; Filipov, F.; Cara, M.

    2009-01-01

    The mass of total carbon from Cambic Chernozem in the Moldavian Plain has recorded significant increases at higher than N 1 40 P 1 00 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 N 1 40 P 1 00 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.

  10. Evaluation of the CropSyst Model during Wheat-Maize Rotations on the North China Plain for Identifying Soil Evaporation Losses

    Directory of Open Access Journals (Sweden)

    Muhammad Umair

    2017-09-01

    Full Text Available The North China Plain (NCP is a major grain production zone that plays a critical role in ensuring China's food supply. Irrigation is commonly used during grain production; however, the high annual water deficit [precipitation (P minus evapotranspiration (ET] in typical irrigated cropland does not support double cropping systems (such as maize and wheat and this has resulted in the steep decline in the water table (~0.8 m year−1 at the Luancheng station that has taken place since the 1970s. The current study aimed to adapt and check the ability of the CropSyst model (Suite-4 to simulate actual evapotranspiration (ETa, biomass, and grain yield, and to identify major evaporation (E losses from winter wheat (WW and summer maize (SM rotations. Field experiments were conducted at the Luancheng Agro-ecosystem station, NCP, in 2010–2011 to 2012–2013. The CropSyst model was calibrated on wheat/maize (from weekly leaf area/biomass data available for 2012–2013 and validated onto measured ETa, biomass, and grain yield at the experimental station from 2010–2011 to 2011–2012, by using model calibration parameters. The revalidation was performed with the ETa, biomass, grain yield, and simulated ETa partition for 2008–2009 WW [ETa partition was measured by the Micro-lysimeter (MLM and isotopes approach available for this year]. For the WW crop, E was 30% of total ETa; but from 2010–11 to 2013, the annual average E was ~40% of ETa for the WW and SM rotation. Furthermore, the WW and SM rotation from 2010–2011 to 2012–2013 was divided into three growth periods; (i pre-sowing irrigation (PSI; sowing at field capacity to emergence period (EP, (ii EP to canopy cover period (CC and (iii CC to harvesting period (HP, and E from each growth period was ~10, 60, and 30%, respectively. In general, error statistics such as RMSE, Willmott's d, and NRMSE in the model evaluation for wheat ETa (maize ETa were 38.3 mm, 0.81, and 9.24% (31.74 mm, 0.73, and 11

  11. Effect of crop sequence and crop residues on soil C, soil N and yield of maize

    International Nuclear Information System (INIS)

    Shafi, M.; Bakht, J.; Attaullah; Khan, M.A.

    2010-01-01

    Improved management of nitrogen (N) in low N soils is critical for increased soil productivity and crop sustainability. The objective of the present study was to evaluate the effects of residues incorporation, residues retention on soil surface as mulch, fertilizer N and legumes in crop rotation on soil fertility and yield of maize (Zea may L.). Fertilizer N was applied to maize at the rate of 160 kg ha/sup -1/, and to wheat at the rate of 120 kg ha/sup -1/ or no fertilizer N application. Crop rotation with the sequence of maize after wheat (Triticum aestivum L.), maize after lentil (Lens culinaris Medic) or wheat after mash bean (Vigna mungo L.) arranged in a split plot design was followed. Post-harvest incorporation of crop residues and residues retention on soil surface as mulch had significantly (p=0.05) affected grain and stover yield during 2004 and 2005. Two years average data revealed that grain yield was increased by 3.31 and 6.72% due to mulch and residues incorporation. Similarly, stover yield was also enhanced by 5.39 and 10.27% due to the same treatment respectively. Mulch and residues incorporation also improved stover N uptake by 2.23 and 6.58%, respectively. Total soil N and organic matter was non significantly (p=0.05) increased by 5.63 and 2.38% due to mulch and 4.13, 7.75% because of crop residues incorporation in the soil. Maize grain and stover yield responded significantly (p=0.05) to the previous legume (lentil) crop when compared with the previous cereal crop (wheat). The treatment of lentil - maize(+N), on the average, increased grain yield of maize by 15.35%, stover yield by 16.84%, total soil N by 10.31% and organic matter by 10.17%. Similarly, fertilizer N applied to the previous wheat showed carry over effect on grain yield (6.82%) and stover yield (11.37%) of the following maize crop. The present study suggested that retention of residues on soil surface as mulch, incorporation of residues in soil and legume (lentil - maize) rotation

  12. Nitrogen use efficiency in organic and conventional vegetable rotations.: Measured and model simulated results

    OpenAIRE

    Thorup-Kristensen, Kristian

    2008-01-01

    Vegetable cropping systems are prone to high nitrogen (N) leaching losses. Optimizing the management of each crop can reduce this problem, but not solve it. Important improvements in cropping system N efficiency can be obtained by improving the rotation, to make sure that N left by some crops are to a large extent used by the succeeding crops. However, this includes rotation and fertilization planning based on a complex set of information on many crop species, on catch crops and green manure ...

  13. Electron Acceleration in the Field-reversed Configuration (FRC) by Slowly Rotation Odd-parity Magnetic Fields (RMFo)

    International Nuclear Information System (INIS)

    Glasser, A.H.; Cohen, S.A.

    2001-01-01

    The trajectories of individual electrons are studied numerically in a 3D, prolate, FRC [field-reversed configuration] equilibrium magnetic geometry with added small-amplitude, slowly rotating, odd-parity magnetic fields (RMFos). RMFos cause electron heating by toroidal acceleration near the O-point line and by field-parallel acceleration away from it, both followed by scattering from magnetic-field inhomogeneities. Electrons accelerated along the O-point line move antiparallel to the FRC's current and attain average toroidal angular speeds near that of the RMFo, independent of the sense of RMFo rotation. A conserved transformed Hamiltonian, dependent on electron energy and RMFo sense, controls electron flux-surface coordinate

  14. Rigid-body rotation of an electron cloud in divergent magnetic fields

    International Nuclear Information System (INIS)

    Fruchtman, A.; Gueroult, R.; Fisch, N. J.

    2013-01-01

    For a given voltage across a divergent poloidal magnetic field, two electric potential distributions, each supported by a rigid-rotor electron cloud rotating with a different frequency, are found analytically. The two rotation frequencies correspond to the slow and fast rotation frequencies known in uniform plasma. Due to the centrifugal force, the equipotential surfaces, that correspond to the two electric potential distributions, diverge more than the magnetic surfaces do, the equipotential surfaces in the fast mode diverge largely in particular. The departure of the equipotential surfaces from the magnetic field surfaces may have a significant focusing effect on the ions accelerated by the electric field. The focusing effect could be important for laboratory plasma accelerators as well as for collimation of astrophysical jets

  15. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems.

    Directory of Open Access Journals (Sweden)

    Moslem Ladoni

    Full Text Available Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover and non-leguminous (winter rye cover crops on potentially mineralizable N (PMN and [Formula: see text] levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4-5 times during each growing season and analyzed for [Formula: see text] and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3-N. Red clover cover crop increased [Formula: see text] by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on [Formula: see text] in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management

  16. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems.

    Science.gov (United States)

    Ladoni, Moslem; Kravchenko, Alexandra N; Robertson, G Phillip

    2015-01-01

    Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and [Formula: see text] levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4-5 times during each growing season and analyzed for [Formula: see text] and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3-N. Red clover cover crop increased [Formula: see text] by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on [Formula: see text] in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row-crop

  17. An electronic pan/tilt/magnify and rotate camera system

    International Nuclear Information System (INIS)

    Zimmermann, S.; Martin, H.L.

    1992-01-01

    A new camera system has been developed for omnidirectional image-viewing applications that provides pan, tilt, magnify, and rotational orientation within a hemispherical field of view (FOV) without any moving parts. The imaging device is based on the fact that the image from a fish-eye lens, which produces a circular image of an entire hemispherical FOV, can be mathematically corrected using high-speed electronic circuitry. More specifically, an incoming fish-eye image from any image acquisition source is captured in the memory of the device, a transformation is performed for the viewing region of interest and viewing direction, and a corrected image is output as a video image signal for viewing, recording, or analysis. The image transformation device can provide corrected images at frame rates compatible with RS-170 standard video equipment. As a result, this device can accomplish the functions of pan, tilt, rotation, and magnification throughout a hemispherical FOV without the need for any mechanical devices. Multiple images, each with different image magnifications and pan-tilt-rotate parameters, can be obtained from a single camera

  18. Breaking continuous potato cropping with legumes improves soil microbial communities, enzyme activities and tuber yield

    Science.gov (United States)

    Qin, Shuhao; Yeboah, Stephen; Cao, Li; Zhang, Junlian; Shi, Shangli; Liu, Yuhui

    2017-01-01

    This study was conducted to explore the changes in soil microbial populations, enzyme activity, and tuber yield under the rotation sequences of Potato–Common vetch (P–C), Potato–Black medic (P–B) and Potato–Longdong alfalfa (P–L) in a semi–arid area of China. The study also determined the effects of continuous potato cropping (without legumes) on the above mentioned soil properties and yield. The number of bacteria increased significantly (p continuous cropping soils, respectively compared to P–C rotation. The highest fungi/bacteria ratio was found in P–C (0.218), followed by P–L (0.184) and then P–B (0.137) rotation over the different cropping years. In the continuous potato cropping soils, the greatest fungi/bacteria ratio was recorded in the 4–year (0.4067) and 7–year (0.4238) cropping soils and these were significantly higher than 1–year (0.3041), 2–year (0.2545) and 3–year (0.3030) cropping soils. Generally, actinomycetes numbers followed the trend P–L>P–C>P–B. The P–L rotation increased aerobic azotobacters in 2–year (by 26% and 18%) and 4–year (40% and 21%) continuous cropping soils compared to P–C and P–B rotation, respectively. Generally, the highest urease and alkaline phosphate activity, respectively, were observed in P–C (55.77 mg g–1) and (27.71 mg g–1), followed by P–B (50.72 mg mg–1) and (25.64 mg g–1) and then P–L (41.61 mg g–1) and (23.26 mg g–1) rotation. Soil urease, alkaline phosphatase and hydrogen peroxidase activities decreased with increasing years of continuous potato cropping. On average, the P–B rotation significantly increased (p improve soil biology environment, alleviate continuous cropping obstacle and increase potato tuber yield in semi–arid region. PMID:28463981

  19. Optical rotation and electron spin resonance of an electro-optically active polythiophene

    International Nuclear Information System (INIS)

    Goto, Hiromasa

    2010-01-01

    Graphical abstract: The electro-chiroptical polythiophene displays optical rotation at wavelengths corresponding to the doping band observable in the absorption spectra. The formation of polarons on the main-chain is confirmed by electron spin resonance measurements. - Abstract: A chiroptical polythiophene, is synthesized by electrolytic polymerization in a cholesteric liquid crystal electrolyte solution. The polymer displays a fingerprint texture similar to that of the cholesteric electrolyte solution. Upon electrochemical doping, the polymer displays optical rotation at wavelengths corresponding to the doping band observable in the absorption spectra. The formation of polarons on the main-chain is confirmed by electron spin resonance measurements. The results demonstrate the intermolecular chirality of polarons in this π-conjugated polymer, indicating continuum delocalized polarons are in a three-dimensional helical environment.

  20. Electron transport in the plasma edge with rotating resonant magnetic perturbations at the TEXTOR tokamak

    International Nuclear Information System (INIS)

    Stoschus, Henning

    2011-01-01

    Small three-dimensional (3D) magnetic perturbations can be used as a tool to control the edge plasma parameters in magnetically confined plasmas in high confinement mode (''H-mode'') to suppress edge instabilities inherent to this regime, the Edge Localized Modes (ELMs). In this work, the impact of rotating 3D resonant magnetic perturbation (RMP) fields on the edge plasma structure characterized by electron density and temperature fields is investigated. We study a low confinement (L-mode) edge plasma (r/a>0.9) with high resistivity (edge electron collisionality ν * e >4) at the TEXTOR tokamak. The plasma structure in the plasma edge is measured by a set of high resolution diagnostics: a fast CCD camera (Δt=20 μs) is set up in order to visualize the plasma structure in terms of electron density variations. A supersonic helium beam diagnostic is established as standard diagnostic at TEXTOR to measure electron density n e and temperature T e with high spatial (Δr=2 mm) and temporal resolution (Δt=20 μs). The measured plasma structure is compared to modeling results from the fluid plasma and kinetic neutral transport code EMC3-EIRENE. A sequence of five new observations is discussed: (1) Imaging of electron density variations in the plasma edge shows that a fast rotating RMP field imposes an edge plasma structure, which rotates with the external RMP rotation frequency of vertical stroke ν RMP vertical stroke =1 kHz. (2) Measurements of the electron density and temperature provide strong experimental evidence that in the far edge a rotating 3D scrape-off layer (SOL) exists with helical exhaust channels to the plasma wall components. (3) Radially inward, the plasma structure at the next rational flux surface is found to depend on the relative rotation between external RMP field and intrinsic plasma rotation. For low relative rotation the plasma structure is dominated by a particle and energy loss along open magnetic field lines to the wall components. For high

  1. Electron transport in the plasma edge with rotating resonant magnetic perturbations at the TEXTOR tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Stoschus, Henning

    2011-10-13

    Small three-dimensional (3D) magnetic perturbations can be used as a tool to control the edge plasma parameters in magnetically confined plasmas in high confinement mode (''H-mode'') to suppress edge instabilities inherent to this regime, the Edge Localized Modes (ELMs). In this work, the impact of rotating 3D resonant magnetic perturbation (RMP) fields on the edge plasma structure characterized by electron density and temperature fields is investigated. We study a low confinement (L-mode) edge plasma (r/a>0.9) with high resistivity (edge electron collisionality {nu}{sup *}{sub e}>4) at the TEXTOR tokamak. The plasma structure in the plasma edge is measured by a set of high resolution diagnostics: a fast CCD camera ({delta}t=20 {mu}s) is set up in order to visualize the plasma structure in terms of electron density variations. A supersonic helium beam diagnostic is established as standard diagnostic at TEXTOR to measure electron density n{sub e} and temperature T{sub e} with high spatial ({delta}r=2 mm) and temporal resolution ({delta}t=20 {mu}s). The measured plasma structure is compared to modeling results from the fluid plasma and kinetic neutral transport code EMC3-EIRENE. A sequence of five new observations is discussed: (1) Imaging of electron density variations in the plasma edge shows that a fast rotating RMP field imposes an edge plasma structure, which rotates with the external RMP rotation frequency of vertical stroke {nu}{sub RMP} vertical stroke =1 kHz. (2) Measurements of the electron density and temperature provide strong experimental evidence that in the far edge a rotating 3D scrape-off layer (SOL) exists with helical exhaust channels to the plasma wall components. (3) Radially inward, the plasma structure at the next rational flux surface is found to depend on the relative rotation between external RMP field and intrinsic plasma rotation. For low relative rotation the plasma structure is dominated by a particle and energy loss

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

    Directory of Open Access Journals (Sweden)

    Carlos Castro

    2008-01-01

    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

  3. The influence of nitrogen fertiliser rate and crop rotation on soil methane flux in rain-fed potato fields in Wuchuan County, China

    International Nuclear Information System (INIS)

    Wang, Liwei; Pan, Zhihua; Xu, Hui; Wang, Cheng; Gao, Lin; Zhao, Peiyi; Dong, Zhiqiang; Zhang, Jingting; Cui, Guohui; Wang, Sen; Han, Guolin; Zhao, Hui

    2015-01-01

    As one of the important greenhouse gases, the characteristics and principles of methane exchange characteristics in cultivated lands have become hot topics in current climate change research. This study examines the influences of nitrogen fertilisation, temperature and soil water content on methane exchange characteristic and methane exchange functional gene-pmoA gene abundance based on experimental observations of methane exchange fluxes using the static chamber–gas chromatographic method and measurements of methanotroph gene copy numbers in three growing periods by real-time PCR in rain-fed potato fields. The results indicate that the rain-fed potato fields were a CH_4 sink with an average annual methane absorption (negative emission) of 940.8 ± 103.2 g CH_4-C/ha/year. The cumulative methane absorption first exhibited flat and subsequently increasing trend with the increase of nitrogen fertilisation from 0 ~ 135 kg N·ha"−"1. Methane cumulative absorption significantly increased with the increase of temperature when temperatures were below 19.6 °C. Methane oxidation capacity (methanotroph pmoA gene copy numbers) showed an increasing and subsequently decreasing trend with the increase of soil moisture. Crop rotation was observed to increase the methane absorption in rain-fed potato fields and nearly one time higher than that under continuous cropping. A mechanism concept model of the methane exchange in rain-fed potato fields was advanced in this paper. - Highlights: • Rain-fed potato fields were a CH_4 sink. • Increased nitrogen fertilisation and temperature led to higher CH_4 absorption. • CH_4 oxidation capacity showed a parabolic trend with soil moisture increased. • Crop rotation increased CH_4 absorption one time higher than continuous cropping. • A mechanism concept model of the CH_4 exchange in potato fields was advanced.

  4. The influence of nitrogen fertiliser rate and crop rotation on soil methane flux in rain-fed potato fields in Wuchuan County, China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Liwei [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); College of Agronomy, Shenyang Agricultural University, Shenyang 110866 (China); Wuchuan Scientific Observing and Experimental Station of Agro-Environment, Ministry of Agriculture Wuchuan 011700 (China); Pan, Zhihua, E-mail: panzhihua@cau.edu.cn [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Wuchuan Scientific Observing and Experimental Station of Agro-Environment, Ministry of Agriculture Wuchuan 011700 (China); Xu, Hui [Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, Cheng [College of Agricultural and Biotechnology, China Agricultural University, Beijing 100193 (China); Gao, Lin [School of Resources and Environmental, Anhui Agricultural University, Hefei 230036 (China); Zhao, Peiyi [Institute of Resources Environmental and Detection Technology, Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences, Huhhot 010031 (China); Wuchuan Scientific Observing and Experimental Station of Agro-Environment, Ministry of Agriculture Wuchuan 011700 (China); Dong, Zhiqiang; Zhang, Jingting; Cui, Guohui; Wang, Sen; Han, Guolin; Zhao, Hui [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Wuchuan Scientific Observing and Experimental Station of Agro-Environment, Ministry of Agriculture Wuchuan 011700 (China)

    2015-12-15

    As one of the important greenhouse gases, the characteristics and principles of methane exchange characteristics in cultivated lands have become hot topics in current climate change research. This study examines the influences of nitrogen fertilisation, temperature and soil water content on methane exchange characteristic and methane exchange functional gene-pmoA gene abundance based on experimental observations of methane exchange fluxes using the static chamber–gas chromatographic method and measurements of methanotroph gene copy numbers in three growing periods by real-time PCR in rain-fed potato fields. The results indicate that the rain-fed potato fields were a CH{sub 4} sink with an average annual methane absorption (negative emission) of 940.8 ± 103.2 g CH{sub 4}-C/ha/year. The cumulative methane absorption first exhibited flat and subsequently increasing trend with the increase of nitrogen fertilisation from 0 ~ 135 kg N·ha{sup −1}. Methane cumulative absorption significantly increased with the increase of temperature when temperatures were below 19.6 °C. Methane oxidation capacity (methanotroph pmoA gene copy numbers) showed an increasing and subsequently decreasing trend with the increase of soil moisture. Crop rotation was observed to increase the methane absorption in rain-fed potato fields and nearly one time higher than that under continuous cropping. A mechanism concept model of the methane exchange in rain-fed potato fields was advanced in this paper. - Highlights: • Rain-fed potato fields were a CH{sub 4} sink. • Increased nitrogen fertilisation and temperature led to higher CH{sub 4} absorption. • CH{sub 4} oxidation capacity showed a parabolic trend with soil moisture increased. • Crop rotation increased CH{sub 4} absorption one time higher than continuous cropping. • A mechanism concept model of the CH{sub 4} exchange in potato fields was advanced.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jitareanu, G.; Ailincai, C.; Bucur, D.; Raus, L.; Filipov, F.; Cara, M.

    2009-07-01

    The mass of total carbon from Cambic Chernozem in the Moldavian Plain has recorded significant increases at higher than N{sub 1}40 P{sub 1}00 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 N{sub 1}40 P{sub 1}00 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{sup -}1 and the content in mobile phosphorus decreased from 51.6 to 36.8 P-Al, mg.kg{sup -}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{sup -}1) and 31%, respectively (11.8 P-Al mg.kg{sup -}1), against maize continuous cropping. (Author) 6 refs.

  6. Economic assessment and comparison of acacia energy crop with annual traditional crops in Southern Europe

    International Nuclear Information System (INIS)

    Gasol, Carles M.; Rieradevall, Joan; Gabarrell, Xavier; Brun, Filippo; Mosso, Angela

    2010-01-01

    In several policy documents bioenergy is recognized as an important renewable energy source in Italy. The increase in energy prices represents an opportunity for lignocellulosic energy crops such as acacia and poplar. However, for Short Rotation Coppice (SRC) and Short Rotation Forestry (SRF) to be adopted by farmers, these crops must be perceived to be at least as profitable as crops that normally compete with these plantations for land use. The purpose of this paper is to evaluate the economic feasibility of acacia (Robinia pseudoacacia) as an energy crop in a low input production regime in Italy and, in particular, to consider its competitiveness with wheat. Our results show that neither SRC and SRF techniques using assumed production costs (EUR3820 and EUR5285 ha -1 yr -1 ) nor biomass productions are able to obtain a positive profit (-EUR184 and -EUR172 ha -1 yr -1 ) that can convince farmers to invest in biomass plantations on their land. The results demonstrate that wheat is a more economically secure option than SRC or SRF. The viability of local biomass production in Italy and Southern Europe depends on the active support of the governments; without them, biomass is not economically competitive for the farmers when compared to crops such as wheat. (author)

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

    International Nuclear Information System (INIS)

    Tolbert, V.R.; Hanowski, J.; Schiller, A.; Hoffman, W.; Christian, D.; Lindberg, J.

    1997-01-01

    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)

  8. Neutral hydrolysable sugars, OC and N content across soil aggregate size fractions, as an effect of two different crop rotations

    Science.gov (United States)

    Angeletti, Carlo; Giannetta, Beatrice; Kölbl, Angelika; Monaci, Elga; Kögel-Knabner, Ingrid; Vischetti, Costantino

    2016-04-01

    This paper presents the results regarding the effects of two 13 years long crop rotations, on the composition of mineral associated neutral sugars, organic carbon (OC) and N concentration, across different aggregate size fractions. The two cropping sequences were characterized by different levels of N input from plant residues and tillage frequency. We also analysed the changes that occurred in soil organic matter (SOM) chemical composition following the cultivation in the two soils of winter wheat and chickpea on the same soils. The analysis of OC and N content across soil aggregate fractions allowed getting an insight into the role played by SOM chemical composition in the formation of organo-mineral associations, while neutral sugars composition provided information on mineral associated SOM origin and decomposition processes, as pentoses derive mostly from plant tissues and hexoses are prevalently of microbial origin. Soil samples were collected from two adjacent fields, from the 0-10 cm layer, in November 2011 (T0). For 13 years before the beginning of the experiment, one soil was cultivated mostly with alfalfa (ALF), while a conventional cereal-sunflower-legume rotation (CON) was carried out on the other. Winter wheat and chickpea were sown on the two soils during the following 2 growing seasons and the sampling was repeated after 18 months (T1). A combination of aggregates size and density fractionation was used to isolate OM associated with mineral particles in: macro-aggregates (>212 μm), micro-aggregates ( 63 μm) and silt and clay size particles (carbohydrates contributions in every other fraction. GM/AX varied slightly between the soils. In conclusion, the crop rotation determined the accumulation of different levels of SOM in the two soils. The 18-months cultivation experiment determined an increase in the tillage intensity in ALF, and the introduction of N rich chickpea residues in CON. Consequently SOM chemical composition responded divergently in

  9. Rotational excitation of N2 by electron impact: 1-4 eV

    International Nuclear Information System (INIS)

    Wong, S.F.; Dube, L.

    1978-01-01

    Rotational and rotational-vibrational (v = 0 → 1) excitation in N 2 have been studied with a crossed-beam electron-impact apparatus. In the energy range 1-4 eV, the elastic and vibrational energy-loss peaks show large rotational broadening compared with the apparatus profile (full width at half-maximum, 18 meV). The branching ratios for rotational transitions with Δj = 0, +- 2, +- 4 are obtained with a line-shape analysis applied to the energy-loss profiles. The results for rotational-vibrational excitation at 2.27 eV and scattering angles 30-90 0 are in good agreement with the calculations using the resonant dπ waves and the rotational impulse approximation. The corresponding results for pure rotational excitation show that the branches with Δj = +- 2 and +- 4 are predominantly excited via resonances, while the branch with Δj = 0 contains a large contribution from direct scattering. The absolute rotational cross sections for Δj = +- 4 are measured; they exhibit a large magnitude (10 -16 cm 2 ) and peak and valley structures in the 1-4 eV range, reminiscent of well-known resonant vibrational excitation. The energy dependence and the absolute magnitude of the rotational cross sections for Δj = +- 4 can be understood in terms of a ''boomerang'' calculation. A comparison of the experiment with the relevant theoretical calculations is made

  10. Calculation of Ground State Rotational Populations for Kinetic Gas Homonuclear Diatomic Molecules including Electron-Impact Excitation and Wall Collisions

    International Nuclear Information System (INIS)

    Farley, David R.

    2010-01-01

    A model has been developed to calculate the ground-state rotational populations of homonuclear diatomic molecules in kinetic gases, including the effects of electron-impact excitation, wall collisions, and gas feed rate. The equations are exact within the accuracy of the cross sections used and of the assumed equilibrating effect of wall collisions. It is found that the inflow of feed gas and equilibrating wall collisions can significantly affect the rotational distribution in competition with non-equilibrating electron-impact effects. The resulting steady-state rotational distributions are generally Boltzmann for N (ge) 3, with a rotational temperature between the wall and feed gas temperatures. The N = 0,1,2 rotational level populations depend sensitively on the relative rates of electron-impact excitation versus wall collision and gas feed rates.

  11. Translational, rotational, vibrational and electron temperatures of a gliding arc discharge

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Ehn, Andreas; Gao, Jinlong

    2017-01-01

    , 0) band was used to simulate the rotational temperature (Tr) of the gliding arc discharge whereas the NO A–X (1, 0) and (0, 1) bands were used to determine its vibrational temperature (Tv). The instantaneous reduced electric field strength E/N was obtained by simultaneously measuring......Translational, rotational, vibrational and electron temperatures of a gliding arc discharge in atmospheric pressure air were experimentally investigated using in situ, non-intrusive optical diagnostic techniques. The gliding arc discharge was driven by a 35 kHz alternating current (AC) power source...... and operated in a glow-type regime. The two-dimensional distribution of the translational temperature (Tt) of the gliding arc discharge was determined using planar laser-induced Rayleigh scattering. The rotational and vibrational temperatures were obtained by simulating the experimental spectra. The OH A–X (0...

  12. Emission of CO2 from energy crop production

    International Nuclear Information System (INIS)

    Turhollow, A.F.

    1991-01-01

    The production of cellulosic energy crops (e.g., short rotation woody crops and herbaceous crops) make a net contribution of CO 2 to the atmosphere to the extent that fossil-fuel based inputs are used in their production. The CO 2 released from the use of the biomass is merely CO 2 that has recently been removed from the atmosphere by the plant growth process. Fossil inputs used in the production of energy corps include energy invested in fertilizers and pesticides, and petroleum fuels used for machinery operation such as site preparation, weed control, harvesting, and hauling. Fossil inputs used come from petroleum, natural gas, and electricity derived from fossil sources. No fossil inputs for the capital used to produce fertilizers, pesticides, or machinery is calculated in this analysis. In this paper calculations are made for the short rotation woody crop hybrid poplar (Populus spp.), the annual herbaceous crop sorghum (Sorghum biocolor [L.] Moench), and the perennial herbaceous crop switchgrass (Panicum virgatum L.). For comparison purposes, emissions of CO 2 from corn (Zea mays L.) are calculated

  13. Quantum switching of π-electron rotations in a nonplanar chiral molecule by using linearly polarized UV laser pulses.

    Science.gov (United States)

    Mineo, Hirobumi; Yamaki, Masahiro; Teranishi, Yoshiaki; Hayashi, Michitoshi; Lin, Sheng Hsien; Fujimura, Yuichi

    2012-09-05

    Nonplanar chiral aromatic molecules are candidates for use as building blocks of multidimensional switching devices because the π electrons can generate ring currents with a variety of directions. We employed (P)-2,2'-biphenol because four patterns of π-electron rotations along the two phenol rings are possible and theoretically determine how quantum switching of the π-electron rotations can be realized. We found that each rotational pattern can be driven by a coherent excitation of two electronic states under two conditions: one is the symmetry of the electronic states and the other is their relative phase. On the basis of the results of quantum dynamics simulations, we propose a quantum control method for sequential switching among the four rotational patterns that can be performed by using ultrashort overlapped pump and dump pulses with properly selected relative phases and photon polarization directions. The results serve as a theoretical basis for the design of confined ultrafast switching of ring currents of nonplanar molecules and further current-induced magnetic fluxes of more sophisticated systems.

  14. Trapped Electron Mode Turbulence Driven Intrinsic Rotation in Tokamak Plasmas

    International Nuclear Information System (INIS)

    Wang, W.X.; Hahm, T.S.; Ethier, S.; Zakharov, L.E.

    2011-01-01

    Recent progress from global gyrokinetic simulations in understanding the origin of intrinsic rotation in toroidal plasmas is reported with emphasis on electron thermal transport dominated regimes. The turbulence driven intrinsic torque associated with nonlinear residual stress generation by the fluctuation intensity and the intensity gradient in the presence of zonal flow shear induced asymmetry in the parallel wavenumber spectrum is shown to scale close to linearly with plasma gradients and the inverse of the plasma current. These results qualitatively reproduce empirical scalings of intrinsic rotation observed in various experiments. The origin of current scaling is found to be due to enhanced kll symmetry breaking induced by the increased radial variation of the safety factor as the current decreases. The physics origin for the linear dependence of intrinsic torque on pressure gradient is that both turbulence intensity and the zonal flow shear, which are two key ingredients for driving residual stress, increase with the strength of turbulence drive, which is R0/LTe and R0/Lne for the trapped electron mode.

  15. Productivity of organic and conventional arable cropping systems in long-term experiments in Denmark

    DEFF Research Database (Denmark)

    Shah, Ambreen; Askegaard, Margrethe; Rasmussen, Ilse Ankjær

    2017-01-01

    manure there was a tendency for increased DM yield over time at all sites, whereas little response was seen in N yield. In the O4 rotation DM and N yields tended to increase at Foulum over time, but there was little change at Flakkebjerg. The DM yield gap between organic and conventional systems in the 3......A field experiment comparing different arable crop rotations was conducted in Denmark during 1997–2008 on three sites varying in climatic conditions and soil types, i.e. coarse sand (Jyndevand), loamy sand (Foulum), and sandy loam (Flakkebjerg). The crop rotations followed organic farm management......, and from 2005 also conventional management was included for comparison. Three experimental factors were included in the experiment in a factorial design: 1) crop rotation (organic crop rotations varying in use of whole-year green manure (O1 and O2 with a whole-year green manure, and O4 without...

  16. Establishment and function of cover crops interseeded into corn

    Science.gov (United States)

    Cover crops can provide ecological services and improve the resiliency of annual cropping systems; however, cover crop use is low in corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotations in the upper Midwest due to challenges with establishment. Our objective was to compare three planting me...

  17. PGOPHER: A program for simulating rotational, vibrational and electronic spectra

    International Nuclear Information System (INIS)

    Western, Colin M.

    2017-01-01

    The PGOPHER program is a general purpose program for simulating and fitting molecular spectra, particularly the rotational structure. The current version can handle linear molecules, symmetric tops and asymmetric tops and many possible transitions, both allowed and forbidden, including multiphoton and Raman spectra in addition to the common electric dipole absorptions. Many different interactions can be included in the calculation, including those arising from electron and nuclear spin, and external electric and magnetic fields. Multiple states and interactions between them can also be accounted for, limited only by available memory. Fitting of experimental data can be to line positions (in many common formats), intensities or band contours and the parameters determined can be level populations as well as rotational constants. PGOPHER is provided with a powerful and flexible graphical user interface to simplify many of the tasks required in simulating, understanding and fitting molecular spectra, including Fortrat diagrams and energy level plots in addition to overlaying experimental and simulated spectra. The program is open source, and can be compiled with open source tools. This paper provides a formal description of the operation of version 9.1. - Highlights: • Easy-to-use graphical interface for assigning and understanding molecular spectra. • Simulates rotational and vibrational structure of many types of molecular spectra. • Fits molecular properties to line positions or spectral contours. • Handles linear molecules and symmetric and asymmetric tops. • Handles perturbations, nuclear and electron spin, and electric and magnetic fields.

  18. Engineering Sclerotinia Sclerotiorum Resistance in Oilseed Crops ...

    African Journals Online (AJOL)

    The fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary is worldwide in distribution and pathogenic to more than 400 plant species. This disease causes significant yield losses of various important crops including sunflower, canola, and soybean. Applying fungicides and crop rotation are currently the major methods of ...

  19. Simultaneous measurement of line electron density and Faraday rotation in the ISX-B tokamak

    International Nuclear Information System (INIS)

    Hutchinson, D.P.; Ma, C.H.; Staats, P.A.; Vander Sluis, K.L.

    1981-01-01

    A new diagnostic system utilizing a submillimetre-wave, phase-modulated polarimeter/interferometer has been used to simultaneously measure the time evolution of the line-averaged electron density and poloidal field-induced Faraday rotation in the ISX-B tokamak. The measurements, performed along four chords of the plasma column, have been correlated with poloidal field changes associated with a ramp in the Ohmic-heating current and by neutral-beam injection. These are the first simultaneous measurements of line electron density and Faraday rotation to be made along a chord of submillimetre laser beam in a tokamak plasma. (author)

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

    DEFF Research Database (Denmark)

    Chirinda, Ngonidzashe; Olesen, Jørgen Eivind; Porter, John Roy

    2010-01-01

    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...... 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...

  1. Crop rotation and seasonal effects on fatty acid profiles of neutral and phospholipids extracted from no-till agricultural soils

    DEFF Research Database (Denmark)

    Ferrari, Alejandro E.; Ravnskov, Sabine; Larsen, John

    2015-01-01

    practices while NLFA 20:0 appears to be a good marker of HRsoils despite season or location. The PLFA-based taxonomic biomarkers for total bacteria, Gramnegativebacteria and arbuscular mycorrhiza showed a significant trend NE>HR>LR in the wintersampling. HR management was also characterized by high levels......Analysis of phospholipids (PLFA) and neutral lipids fatty acids (NLFA) was used to characterizeno-till productive agricultural soils associated with different crop rotation levels, replicated across a400 km transect in the Argentinean pampas, during two sampling seasons, summer and winter...

  2. No-till Organic Soybean Production Following a Fall-planted Rye Cover Crop

    OpenAIRE

    Porter, Paul; Feyereisen, Gary; De Bruin, Jason; Johnson, Gregg

    2005-01-01

    The conventional corn-soybean rotation in the United States (USA) is a leaky system with respect to nitrate-nitrogen (nitrate-N), in part because these crops grow only five months of the year. Ecosystem functioning can be improved with the use of an appropriate fall-planted cover crop, but this practice is not common. Organic soybean production in the USA typically relies on delayed planting, crop rotation, intensive harrowing and interrow cultivation for weed control. Research on timing of ...

  3. Long-term effects of conservation systems on productivity for the old rotation

    Science.gov (United States)

    Winter legumes in cotton (Gossypium hirsutum L.) production is not new to the Southeast. In 1896, the Old Rotation experiment at Auburn University was established to study the feasibility of producing cotton in crop rotations with winter legumes managed as a green manure crop. Throughout the experim...

  4. Remote sensing to monitor cover crop adoption in southeastern Pennsylvania

    Science.gov (United States)

    In the Chesapeake Bay watershed, winter cereal cover crops are often planted in rotation with summer crops to reduce the loss of nutrients and sediment from agricultural systems. Cover crops can also improve soil health, control weeds and pests, supplement forage needs, and support resilient croppin...

  5. Regulation of Population Densities of Heterodera cajani and Other Plant-Parasitic Nematodes by Crop Rotations on Vertisols, in Semi-Arid Tropical Production Systems in India

    Science.gov (United States)

    Sharma, S. B.; Rego, T. J.; Mohiuddin, M.; Rao, V. N.

    1996-01-01

    The significance of double crop (intercrop and sequential crop), single crop (rainy season crop fallow from June to September), and rotations on densities of Heterodera cajani, Helicotylenchus retusus, and Rotylenchulus reniformis was studied on Vertisol (Typic Pellusterts) between 1987 and 1993. Cowpea (Vigna sinensis), mungbean (Phaseolus aureus), and pigeonpea (Cajanus cajan) greatly increased the population densities of H. cajani and suppressed the population densities of other plant-parasitic nematodes. Mean population densities of H. cajani were about 8 times lower in single crop systems than in double crop systems, with pigeonpea as a component intercrop. Plots planted to sorghum, safflower, and chickpea in the preceding year contained fewer H. cajani eggs and juveniles than did plots previously planted to pigeonpea, cowpea, or mungbean. Continuous cropping of sorghum in the rainy season and safflower in the post-rainy season markedly reduced the population density of H. cajani. Sorghum, safflower, and chickpea favored increased population densities of H. retusus. Adding cowpea to the system resulted in a significant increase in the densities of R. reniformis. Mean densities of total plant-parasitic nematodes were three times greater in double crop systems, with pigeonpea as a component intercrop than in single crop systems with rainy season fallow component. Cropping systems had a regulatory effect on the nematode populations and could be an effective nematode management tactic. Intercropping of sorghum with H. cajani tolerant pigeonpea could be effective in increasing the productivity of traditional production systems in H. cajani infested regions. PMID:19277141

  6. Impact of crop residue management on crop production and soil chemistry after seven years of crop rotation in temperate climate, loamy soils.

    Science.gov (United States)

    Hiel, Marie-Pierre; Barbieux, Sophie; Pierreux, Jérôme; Olivier, Claire; Lobet, Guillaume; Roisin, Christian; Garré, Sarah; Colinet, Gilles; Bodson, Bernard; Dumont, Benjamin

    2018-01-01

    Society is increasingly demanding a more sustainable management of agro-ecosystems in a context of climate change and an ever growing global population. The fate of crop residues is one of the important management aspects under debate, since it represents an unneglectable quantity of organic matter which can be kept in or removed from the agro-ecosystem. The topic of residue management is not new, but the need for global conclusion on the impact of crop residue management on the agro-ecosystem linked to local pedo-climatic conditions has become apparent with an increasing amount of studies showing a diversity of conclusions. This study specifically focusses on temperate climate and loamy soil using a seven-year data set. Between 2008 and 2016, we compared four contrasting residue management strategies differing in the amount of crop residues returned to the soil (incorporation vs. exportation of residues) and in the type of tillage (reduced tillage (10 cm depth) vs. conventional tillage (ploughing at 25 cm depth)) in a field experiment. We assessed the impact of the crop residue management on crop production (three crops-winter wheat, faba bean and maize-cultivated over six cropping seasons), soil organic carbon content, nitrate ([Formula: see text]), phosphorus (P) and potassium (K) soil content and uptake by the crops. The main differences came primarily from the tillage practice and less from the restitution or removal of residues. All years and crops combined, conventional tillage resulted in a yield advantage of 3.4% as compared to reduced tillage, which can be partly explained by a lower germination rate observed under reduced tillage, especially during drier years. On average, only small differences were observed for total organic carbon (TOC) content of the soil, but reduced tillage resulted in a very clear stratification of TOC and also of P and K content as compared to conventional tillage. We observed no effect of residue management on the [Formula: see

  7. Contribution of Legume Rotations to the Nitrogen Requirements of a ...

    African Journals Online (AJOL)

    Cereal crop yield improvements following legume rotations ... effects of legumes rotation in meeting the N fertilizer requirements of maize. ... The effects of the rotations on increasing the maize yields were equivalent to application of 25, 19 and.

  8. Winter rye cover crops as a host for corn seedling pathogens

    Science.gov (United States)

    Cover cropping is a prevalent conservation practice that offers substantial benefits to soil protection, soil health and water quality. However, emerging implementations of cover cropping, such as winter cereals preceding corn, may dampen beneficial rotation effects by putting similar crop species i...

  9. Quantum coherent π-electron rotations in a non-planar chiral molecule induced by using a linearly polarized UV laser pulse

    Science.gov (United States)

    Mineo, Hirobumi; Fujimura, Yuichi

    2015-06-01

    We propose an ultrafast quantum switching method of π-electron rotations, which are switched among four rotational patterns in a nonplanar chiral aromatic molecule (P)-2,2’- biphenol and perform the sequential switching among four rotational patterns which are performed by the overlapped pump-dump laser pulses. Coherent π-electron dynamics are generated by applying the linearly polarized UV pulse laser to create a pair of coherent quasidegenerated excited states. We also plot the time-dependent π-electron ring current, and discussed ring current transfer between two aromatic rings.

  10. Structural study of disordered SiC nanowires by three-dimensional rotation electron diffraction

    International Nuclear Information System (INIS)

    Li, Duan; Guo, Peng; Wan, Wei; Zou, Ji; Shen, Zhijian; Guzi de Moraes, Elisângela; Colombo, Paolo

    2014-01-01

    The structure of disordered SiC nanowires was studied by using the three-dimensional rotation electron diffraction (RED) technique. The streaks shown in the RED images indicated the stacking faults of the nanowire. High-resolution transmission electron microscopy imaging was employed to support the results from the RED data. It suggested that a 2H polytype is most possible for the nanowires. (paper)

  11. Impacts of crop growth dynamics on soil quality at the regional scale

    Science.gov (United States)

    Gobin, Anne

    2014-05-01

    Agricultural land use and in particular crop growth dynamics can greatly affect soil quality. Both the amount of soil lost from erosion by water and soil organic matter are key indicators for soil quality. The aim was to develop a modelling framework for quantifying the impacts of crop growth dynamics on soil quality at the regional scale with test case Flanders. A framework for modelling the impacts of crop growth on soil erosion and soil organic matter was developed by coupling the dynamic crop cover model REGCROP (Gobin, 2010) to the PESERA soil erosion model (Kirkby et al., 2009) and to the RothC carbon model (Coleman and Jenkinson, 1999). All three models are process-based, spatially distributed and intended as a regional diagnostic tool. A geo-database was constructed covering 10 years of crop rotation in Flanders using the IACS parcel registration (Integrated Administration and Control System). Crop allometric models were developed from variety trials to calculate crop residues for common crops in Flanders and subsequently derive stable organic matter fluxes to the soil. Results indicate that crop growth dynamics and crop rotations influence soil quality for a very large percentage. soil erosion mainly occurs in the southern part of Flanders, where silty to loamy soils and a hilly topography are responsible for soil loss rates of up to 40 t/ha. Parcels under maize, sugar beet and potatoes are most vulnerable to soil erosion. Crop residues of grain maize and winter wheat followed by catch crops contribute most to the total carbon sequestered in agricultural soils. For the same rotations carbon sequestration is highest on clay soils and lowest on sandy soils. This implies that agricultural policies that impact on agricultural land management influence soil quality for a large percentage. The coupled REGCROP-PESERA-ROTHC model allows for quantifying the impact of seasonal and year-to-year crop growth dynamics on soil quality. When coupled to a multi-annual crop

  12. A thermal analysis for the use of cooled rotating drums in electron processing

    International Nuclear Information System (INIS)

    Fletcher, P.M.; Williams, K.E.

    1988-01-01

    The thermal response of rotating drums under an electron beam has been analyzed using a finite difference thermal analysis computer code. Rotating drums are used to convey thin webs or films under the electron beams while controlling their temperature and, in some cases, in dissipating the exotherm involved in curing coatings applied to them. Each portion of the drum surface receives one heat pulse per rotation as it passes under the beam. The drum's thermal behavior shows both an immediate response to each heat pulse and a more gradual response to the average heat acquired over many pulses. After many rotations a steady state is reached where there is only an immediate response to each heat pulse but the gradual heating has tapered off. Nevertheless the steady state temperatures are strongly dependent on the gradual heating that led to them. Slow and fast speeds of rotation are compared showing the effects of both gradual and immediate heating components. The thermal analysis is extended to include the coolant fluid inside the drum shell and the web on the drum surface. The coolant's incoming temperature, volumetric flow rate, flow speed through the coolant channels and film coefficient between the outer shell and fluid are all included in the analysis. The small air gap between the web and drum, the convective cooling of the web to the ambient air, and the exothermic reaction of any chemical reactions on the web are included. The stresses produced in the drum shell (i.e. between the outer surface and the temperature-controlling fluid within the drum) are analyzed in order to define safe e-beam powers and rotating speeds. The analysis provides the basis for many design decisions and can give an end-user a full temperature history for his product for any set of conditions. (author)

  13. In Situ Groundwater Denitrification in the Riparian Zone of a Short-Rotation Woody Crop Experimental Watershed

    Science.gov (United States)

    Jeffers, J. B.; Jackson, C. R.; Rau, B.; Pringle, C. M.; Matteson, C.

    2017-12-01

    The southeastern United States has potential to become a major producer of short rotation woody crops (SRWC) for the production of biofuels, but this will require converting to more intensive forest management practices that will increase nitrate (NO3-) loading and alter nitrogen cycling in nearby freshwater ecosystems. Water quality monitoring in an experimental short-rotation woody crop watershed in the Coastal Plain of South Carolina has shown increased concentrations of NO3- in groundwater but no evidence of increased NO3- in riparian groundwater or surface waters. Forested riparian areas established as streamside management zones (SMZ) are known to act as buffers to surface water bodies by mitigating nutrients. The objectives of this study were to quantify denitrification by measuring dinitrogen (N2) and nitrous oxide (N2O) concentrations along groundwater flow paths and analyze relationships between denitrification estimates, nutrients, and water chemistry parameters. A network of piezometers has been established in the Fourmile Experimental Watershed at the Department of Energy - Savannah River Site. Water samples were collected monthly and were analyzed for concentrations of nutrients (temperature, specific conductivity, dissolved oxygen, pH, dissolved organic carbon) and dissolved gases (N2, Ar, N2O). Preliminary data showed greater dissolved N2O concentrations than dissolved N2 concentrations in groundwater. The ratios of N2O to combined end products of denitrification (N2O / N2O+N2) ranged from 0.33 to 0.99. Mean N2O+N2 concentrations were greater in groundwater samples in the SRWC plot and along the SMZ boundary than along the ephemeral stream within the riparian zone. Correlations between water chemistry parameters and N2 concentrations are indicative of known biogeochemical driving factors of denitrification. Continued monthly sampling will be coupled with analysis of nutrient concentrations (NO3-, NH4+, TN) to help determine transport and processing

  14. Soil Management Practices to Improve Nutrient-use Efficiencies and Reduce Risk in Millet-based Cropping Systems in the Sahel

    Directory of Open Access Journals (Sweden)

    Koala, S.

    2003-01-01

    Full Text Available Low soil fertility and moisture deficit are among the main constraints to sustainable crop yields in the Sahel. A study therefore, was conducted at the ICRISAT Sahelian Center, Sadore in Niger to test the hypothesis that integrated soil husbandry practices consisting of manure, fertilizer and crop residues in rotational cropping systems use organic and mineral fertilizes efficiently, thereby resulting in higher yields and reduced risk. Results from an analysis of variance showed that choice of cropping systems explained more than 50% of overall variability in millet and cowpea grain yields. Among the cropping systems, rotation gave higher yields than sole crop and intercropping systems and increased millet yield by 46% without fertilizer. Rainfall-use efficiency and partial factor productivity of fertilizer were similarly higher in rotations than in millet monoculture system. Returns from cowpea grown in cowpea-millet rotation without fertilizer and the medium rates of fertilizers (4 kg P.ha-1 + 15 kg N.ha-1 were found to be most profitable in terms of high returns and low risk, principally because of a higher price of cowpea than millet. The study recommends crop diversification, either in the form of rotations or relay intercropping systems for the Sahel as an insurance against total crop failure.

  15. Effect of temperature and precipitation on nitrate leaching from organic cereal cropping systems in Denmark

    DEFF Research Database (Denmark)

    Jabloun, Mohamed; Schelde, Kirsten; Tao, F

    2015-01-01

    The effect of variation in seasonal temperature and precipitation on soil water nitrate (NO3single bondN) concentration and leaching from winter and spring cereals cropping systems was investigated over three consecutive four-year crop rotation cycles from 1997 to 2008 in an organic farming crop...... rotation experiment in Denmark. Three experimental sites, varying in climate and soil type from coarse sand to sandy loam, were investigated. The experiment included experimental treatments with different rotations, manure rate and cover crop, and soil nitrate concentrations was monitored using suction......N concentration for winter and spring cereals, respectively, and 68% and 77% of the variation in the square root transform of annual NO3single bondN leaching for winter and spring cereals, respectively. Nitrate concentration and leaching were shown to be site specific and driven by climatic factors and crop...

  16. Continuous cropping with 13 - 15 inches of precipitation

    Science.gov (United States)

    Producers in the Great Plains have use fallow to adjust for inconsistent and often, inadequate rainfall. The prevalent rotation in this region is winter wheat-fallow. Fallow, however, is damaging to soil health. No-till practices have enabled producers to include more crops in the rotation. This...

  17. Population dynamics of Meloidogyne arenaria and Pasteuria penetrans in a long-term crop rotation study.

    Science.gov (United States)

    Timper, Patricia

    2009-12-01

    The endospore-forming bacterium Pasteuria penetrans is an obligate parasite of root-knot nematodes (Meloidogyne spp.). The primary objective of this study was to determine the effect of crop sequence on abundance of P. penetrans. The experiment was conducted from 2000 to 2008 at a field site naturally infested with both the bacterium and its host Meloidogyne arenaria and included the following crop sequences: continuous peanut (Arachis hypogaea) (P-P-P) and peanut rotated with either 2 years of corn (Zea mays) (C-C-P), 1 year each of cotton (Gossypium hirsutum) and corn (Ct-C-P), or 1 year each of corn and a vegetable (V-C-P). The vegetable was a double crop of sweet corn and eggplant (Solanum melongena). A bioassay with second-stage juveniles (J2) of M. arenaria from a greenhouse (GH) population was used to estimate endospore abundance under the different crop sequences. A greater numerical increase in endospore densities was expected in the P-P-P and V-C-P sequences than in the other sequences because both peanut and eggplant are good hosts for M. arenaria. However, endospore densities, as determined by bioassay, did not substantially increase in any of the sequences during the 9-year experiment. To determine whether the nematode population had developed resistance to the resident P. penetrans, five single egg-mass (SEM) lines from the field population of M. arenaria were tested alongside the GH population for acquisition of endospores from the field soil. Four of the five SEM lines acquired 9 to 14 spores/J2 whereas the GH population and one of the SEM lines acquired 3.5 and 1.8 spores/J2, respectively. Endospore densities estimated with the four receptive SEM lines were highest in the P-P-P plots (14-20 spores/J2), intermediate in the V-C-P plots (6-7 spores/J2), and lowest in the Ct-C-P plots (< 1 spore/J2). These results indicate that the field population of M. arenaria is heterogeneous for attachment of P. penetrans endospores. Moreover, spore densities

  18. Population Dynamics of Meloidogyne arenaria and Pasteuria penetrans in a Long-Term Crop Rotation Study

    Science.gov (United States)

    2009-01-01

    The endospore-forming bacterium Pasteuria penetrans is an obligate parasite of root-knot nematodes (Meloidogyne spp.). The primary objective of this study was to determine the effect of crop sequence on abundance of P. penetrans. The experiment was conducted from 2000 to 2008 at a field site naturally infested with both the bacterium and its host Meloidogyne arenaria and included the following crop sequences: continuous peanut (Arachis hypogaea) (P-P-P) and peanut rotated with either 2 years of corn (Zea mays) (C-C-P), 1 year each of cotton (Gossypium hirsutum) and corn (Ct-C-P), or 1 year each of corn and a vegetable (V-C-P). The vegetable was a double crop of sweet corn and eggplant (Solanum melongena). A bioassay with second-stage juveniles (J2) of M. arenaria from a greenhouse (GH) population was used to estimate endospore abundance under the different crop sequences. A greater numerical increase in endospore densities was expected in the P-P-P and V-C-P sequences than in the other sequences because both peanut and eggplant are good hosts for M. arenaria. However, endospore densities, as determined by bioassay, did not substantially increase in any of the sequences during the 9-year experiment. To determine whether the nematode population had developed resistance to the resident P. penetrans, five single egg-mass (SEM) lines from the field population of M. arenaria were tested alongside the GH population for acquisition of endospores from the field soil. Four of the five SEM lines acquired 9 to 14 spores/J2 whereas the GH population and one of the SEM lines acquired 3.5 and 1.8 spores/J2, respectively. Endospore densities estimated with the four receptive SEM lines were highest in the P-P-P plots (14-20 spores/J2), intermediate in the V-C-P plots (6-7 spores/J2), and lowest in the Ct-C-P plots (< 1 spore/J2). These results indicate that the field population of M. arenaria is heterogeneous for attachment of P. penetrans endospores. Moreover, spore densities

  19. Woody crops conference 2013; Agrarholz-Kongress 2013

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-06-01

    Within the Guelzow expert discussions at 19th and 20th February 2013 in Berlin (Federal Republic of Germany) the following lectures were held: (1) Research funding of the BMELV in the field of the production of woody crops (Andreas Schuette); (2) ELKE - Development of extensive concepts of land use for the production of renewable raw materials as possible compensatory measures and substitute measures (Frank Wegener); (3) Knowledge transfer to the realm of practice, experiences of the DLG (Frank Setzer); (4) Results of the tests with fast growing tree species after 18 years of cultivation in Guelzow (Andreas Gurgel); (5) Latest findings on the production of woody crops in Brandenburg (D. Murach); (6) Phytosanitary situation in short-rotation coppices in Germany - Current state of knowledge and prognoses for the future (Christiane Helbig); (7) Evaluation of alternative delivery procedures in short-rotation coppices (Janine Schweier); (8) With a short-rotation coppice shredder through Germany (Wolfram Kudlich); (9) Changes of land-use of traditional crops rotation systems to short-rotation coppices consisting of poplar trees and willow trees, which sites are suitable? - Selected results from the ProLoc association (Martin Hofmann); (10) Cultivation of populus tremula for short-rotation coppices at agricultural areas (Mirko Liesebach); (11) Investigations of the resistance behaviour of newly developed black poplar clones and balsam poplar clones against the poplar leave rust Melampsora larici-populina (Christina Fey-Wagner); (12) A agri-forestry system for ligneous energy production in the organic farming - First results from cultivation experiments in Bavaria (Klaus Wiesinger); (13) Implementation of agri-forestry systems with energy wood in the rural area - the project AgroForstEnergie (Armin Vetter); (14) Impact of agroforestry land utilization on microclimate, soil fertility and quality of water (Christian Boehm).

  20. SEBS validation in a Spanish rotating crop

    NARCIS (Netherlands)

    Pardo, N.; Sanchez, M.L.; Timmermans, J.; Su, Zhongbo; Perez, I.A.; Garcia, M.A.

    2014-01-01

    This paper focuses on calculating Evaporative Fraction (EF) and energy balance components, applying the Surface Energy Balance System (SEBS) model combined with remote sensing products and meteorological data over an agricultural rotating cropland from 2008 to 2011. The model is validated by

  1. Impact of crop residue management on crop production and soil chemistry after seven years of crop rotation in temperate climate, loamy soils

    Directory of Open Access Journals (Sweden)

    Marie-Pierre Hiel

    2018-05-01

    Full Text Available Society is increasingly demanding a more sustainable management of agro-ecosystems in a context of climate change and an ever growing global population. The fate of crop residues is one of the important management aspects under debate, since it represents an unneglectable quantity of organic matter which can be kept in or removed from the agro-ecosystem. The topic of residue management is not new, but the need for global conclusion on the impact of crop residue management on the agro-ecosystem linked to local pedo-climatic conditions has become apparent with an increasing amount of studies showing a diversity of conclusions. This study specifically focusses on temperate climate and loamy soil using a seven-year data set. Between 2008 and 2016, we compared four contrasting residue management strategies differing in the amount of crop residues returned to the soil (incorporation vs. exportation of residues and in the type of tillage (reduced tillage (10 cm depth vs. conventional tillage (ploughing at 25 cm depth in a field experiment. We assessed the impact of the crop residue management on crop production (three crops—winter wheat, faba bean and maize—cultivated over six cropping seasons, soil organic carbon content, nitrate ( ${\\mathrm{NO}}_{3}^{-}$ NO 3 − , phosphorus (P and potassium (K soil content and uptake by the crops. The main differences came primarily from the tillage practice and less from the restitution or removal of residues. All years and crops combined, conventional tillage resulted in a yield advantage of 3.4% as compared to reduced tillage, which can be partly explained by a lower germination rate observed under reduced tillage, especially during drier years. On average, only small differences were observed for total organic carbon (TOC content of the soil, but reduced tillage resulted in a very clear stratification of TOC and also of P and K content as compared to conventional tillage. We observed no effect of residue

  2. Sustainable Agriculture: Cover Cropping

    Science.gov (United States)

    Webster, Megan

    2018-01-01

    Sustainable agriculture practices are increasingly being used by farmers to maintain soil quality, increase biodiversity, and promote production of food that is environmentally safe. There are several types of sustainable agriculture practices such as organic farming, crop rotation, and aquaculture. This lesson plan focuses on the sustainable…

  3. Global warming likely reduces crop yield and water availability of the dryland cropping systems in the U.S. central Great Plains

    Science.gov (United States)

    We investigated impacts of GCM-projected climate change on dryland crop rotations of wheat-fallow and wheat-corn-fallow in the Central Great Plains (Akron in Colorado, USA) using the CERES 4.0 crop modules in RZWQM2. The climate change scenarios for CO2, temperature, and precipitation were produced ...

  4. One-electron densities of freely rotating Wigner molecules

    Science.gov (United States)

    Cioslowski, Jerzy

    2017-12-01

    A formalism enabling computation of the one-particle density of a freely rotating assembly of identical particles that vibrate about their equilibrium positions with amplitudes much smaller than their average distances is presented. It produces densities as finite sums of products of angular and radial functions, the length of the expansion being determined by the interplay between the point-group and permutational symmetries of the system in question. Obtaining from a convolution of the rotational and bosonic components of the parent wavefunction, the angular functions are state-dependent. On the other hand, the radial functions are Gaussians with maxima located at the equilibrium lengths of the position vectors of individual particles and exponents depending on the scalar products of these vectors and the eigenvectors of the corresponding Hessian as well as the respective eigenvalues. Although the new formalism is particularly useful for studies of the Wigner molecules formed by electrons subject to weak confining potentials, it is readily adaptable to species (such as ´balliums’ and Coulomb crystals) composed of identical particles with arbitrary spin statistics and permutational symmetry. Several examples of applications of the present approach to the harmonium atoms within the strong-correlation regime are given.

  5. Imitating model of the electronic regulator frequencies of rotation of the automobile diesel engine

    OpenAIRE

    Тырловой, С. И.

    2011-01-01

    The imitating model of an frequency electronic regulator of rotation of high-speed diesel engine an automobile diesel engine with the distributive fuel pump of Bosch company is resulted. Is executed simulation transitive modes of a diesel engine with mechanic and electronic regulators. Deterioration influence plungers steams on dinamic and economic indicators of a diesel engine is analysed. Operational indicators of a diesel engine with mechanic and electronic regulators are compared. The obt...

  6. Bibliography on electron collisions with molecules: rotational and vibrational excitations, 1980-2000

    International Nuclear Information System (INIS)

    Itikawa, Yukikazu

    2001-04-01

    A list of papers reporting cross sections for electron-impact excitations of rotational and vibrational states of molecules is presented. The list includes both the theoretical and the experimental papers published in 1980-2000. An index by molecular species is provided at the end of the bibliography. (author)

  7. Comparison between land suitability and actual crop distribution in an irrigation district of the Ebro valley (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Casanovas, J. A.; Klaasse, A.; Nogues, J.; Ramos, M. C.

    2008-07-01

    The present research aims to obtain a better insight into the agreement between land evaluation results and actual crop spatial distribution by comparing biophysical land suitability with different crop frequency parameters and with crop rotations derived from multi-year crop maps. The research was carried out in the Flumen district (33,000 ha), which is located in the Ebro Valley (northeast Spain). Land evaluation was based on a 1:100,000 soil survey according to the FAO framework for the main crops in the study area (alfalfa, winter cereals, maize, rice and sunflower). Three crop frequency maps and a crop rotation map, derived from a time-series of Landsat TM and ETM+ images of the period 1993-2000 were used for comparison with land suitability maps. The relationships between the two types of variables were analyzed by means of statistical tests (Pearson chi-square ({chi}{sup 2}), Cramer Ls V, Gamma and Somers L D). The results show the existence of a significant (P=0.001) relationship between crops location and land suitability, except for opportunist crops as sunflower, which is very much influenced by subsidies in the study period. The alfalfa-based rotations show the highest distribution percentages (52%) on the land most suitable for agriculture in the area. The present multi temporal analysis approach offers a more realistic insight than the comparison between a land evaluation map and static year crop map in assessing the degree of agreement of land evaluation recommendations with crops actually cultivated by farmers. Additional key words: biophysical land suitability, crop rotation, land evaluation. (Author) 35 refs.

  8. Impact of perennial energy crops income variability on the crop selection of risk averse farmers

    International Nuclear Information System (INIS)

    Alexander, Peter; Moran, Dominic

    2013-01-01

    The UK Government policy is for the area of perennial energy crops in the UK to expand significantly. Farmers need to choose these crops in preference to conventional rotations for this to be achievable. This paper looks at the potential level and variability of perennial energy crop incomes and the relation to incomes from conventional arable crops. Assuming energy crop prices are correlated to oil prices the results suggests that incomes from them are not well correlated to conventional arable crop incomes. A farm scale mathematical programming model is then used to attempt to understand the affect on risk averse farmers crop selection. The inclusion of risk reduces the energy crop price required for the selection of these crops. However yields towards the highest of those predicted in the UK are still required to make them an optimal choice, suggesting only a small area of energy crops within the UK would be expected to be chosen to be grown. This must be regarded as a tentative conclusion, primarily due to high sensitivity found to crop yields, resulting in the proposal for further work to apply the model using spatially disaggregated data. - Highlights: ► Energy crop and conventional crop incomes suggested as uncorrelated. ► Diversification effect of energy crops investigated for a risk averse farmer. ► Energy crops indicated as optimal selection only on highest yielding UK sites. ► Large establishment grant rates to substantially alter crop selections.

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

    Directory of Open Access Journals (Sweden)

    Eric D. Vance

    2014-05-01

    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.

  10. Interplay of oxygen octahedral rotations and electronic instabilities in strontium ruthenate Ruddlesden-Poppers from first principles

    Science.gov (United States)

    Voss, Johannes; Fennie, Craig J.

    2011-03-01

    The Ruddlesden-Popper ruthenates Sr n+1 Ru n O3 n + 1 display a broad range of electronic phases including p -wave superconductivity, electronic nematicity, and ferromagnetism. Elucidating the role of the number of perovskite blocks, n , in the realization of these differently ordered electronic states remains a challenge. Additionally dramatic experimental advances now enable the atomic scale growth of these complex oxide thin films on a variety of substrates coherently, allowing for the application of tunable epitaxial strain and subsequently the ability to control structural distortions such as oxygen octahedral rotations. Here we investigate from first principles the effect of oxygen octahedral rotations on the electronic structure of Sr 2 Ru O4 and Sr 3 Ru 2 O7 . We discuss possible implications for the physics of the bulk systems and point towards new effects in thin films.

  11. Quantum mechanical study of elastic scattering and rotational excitation of CO by electrons

    Science.gov (United States)

    Onda, K.; Truhlar, D. G.

    1980-01-01

    Coupling calculations of differential, integral, and momentum transfer cross sections for pure elastic scattering and rotational excitation of CO by electron impact are reported. The calculations are based on a static charge distribution that has correct dipole and quadrupole moments, has cusps at the nuclei, and is augmented by an SCF treatment of charge polarization and a local approximation for exchange. The rotationally summed cross sections, with no adjustable parameters in the scattering calculation, are in reasonably good agreement with the experimental cross sections but are somewhat larger at small scattering angles.

  12. Rotation history effects on soybean plants and rhizosphere microbiome

    Science.gov (United States)

    Benefits of diversified cropping systems stem from the interactions between soil characteristics, crop growth patterns and physiology, and other organisms. In order to assist in the understanding and implementation of diversified rotation sequences, a long-term experiment was established to evaluate...

  13. The development of the EU-Rotate_N and its use to test strategies for N use across Europe

    DEFF Research Database (Denmark)

    Rahn, C.R.; Zhang, K.; Lillywhite, R.

    2010-01-01

    A new model EU-ROTATE_N has been written which enables the assessment of the economic and environmental performance of nitrogen applied to crop rotations in either conventional or organic cropping for a wide range of crops and growing conditions in Europe. The model can simulate root development,...

  14. A Medipix quantum area detector allows rotation electron diffraction data collection from submicrometre three-dimensional protein crystals

    International Nuclear Information System (INIS)

    Nederlof, Igor; Genderen, Eric van; Li, Yao-Wang; Abrahams, Jan Pieter

    2013-01-01

    An ultrasensitive Medipix2 detector allowed the collection of rotation electron-diffraction data from single three-dimensional protein nanocrystals for the first time. The data could be analysed using the standard X-ray crystallography programs MOSFLM and SCALA. When protein crystals are submicrometre-sized, X-ray radiation damage precludes conventional diffraction data collection. For crystals that are of the order of 100 nm in size, at best only single-shot diffraction patterns can be collected and rotation data collection has not been possible, irrespective of the diffraction technique used. Here, it is shown that at a very low electron dose (at most 0.1 e − Å −2 ), a Medipix2 quantum area detector is sufficiently sensitive to allow the collection of a 30-frame rotation series of 200 keV electron-diffraction data from a single ∼100 nm thick protein crystal. A highly parallel 200 keV electron beam (λ = 0.025 Å) allowed observation of the curvature of the Ewald sphere at low resolution, indicating a combined mosaic spread/beam divergence of at most 0.4°. This result shows that volumes of crystal with low mosaicity can be pinpointed in electron diffraction. It is also shown that strategies and data-analysis software (MOSFLM and SCALA) from X-ray protein crystallography can be used in principle for analysing electron-diffraction data from three-dimensional nanocrystals of proteins

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

    Energy Technology Data Exchange (ETDEWEB)

    Boehmel, Ute Constanze

    2007-07-18

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

  16. Enhanced Yields in Organic Arable Crop Production by Eco-Functional Intensification using Intercropping

    DEFF Research Database (Denmark)

    Jensen, Erik Steen; Bedoussac, Laurent; Carlsson, Georg

    2015-01-01

    for enhancing yields in OA. EFI involves activating more knowledge and intensifying the beneficial effects of ecosystem functions, including agrobiodiversity (planned and associated) and soil fertility, and refocusing the importance of ecosystems services in agriculture. Organic farmers manage agrobiodiversity...... in space by intercropping, fitted into the organic crop rotation, has a strong potential to increase yield and hereby reduce the global environmental effects performance such as GHG per kg organic grain. Finally, we discuss likely barriers for increased use of intercropping in organic farming and suggest...... by planned crop diversification in time (crop rotation). However, cultivating genetically identical plants in OA sole crops (SC), limits resource use efficiency and yield per unit area. Intercropping (IC) of annual species or cultivars, perennial polycultures of forage or grain crops and agroforestry...

  17. Increasing Cropping System Diversity Balances Productivity, Profitability and Environmental Health

    Science.gov (United States)

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

    2012-01-01

    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

  18. Effects of nitrogen and phosphorus fertilizer on crop yields in a field pea-spring wheat-potato rotation system with calcareous soil in semi-arid environments

    Directory of Open Access Journals (Sweden)

    Chang-An Liu

    2016-06-01

    Full Text Available The object of the present study was to investigate the yield-affecting mechanisms influenced by N and P applications in rainfed areas with calcareous soil. The experimental treatments were as follows: NF (no fertilizer, N (nitrogen, P (phosphorus, and NP (nitrogen plus phosphorus in a field pea-spring wheat-potato cropping system. This study was conducted over six years (2003-2008 on China’s semi-arid Loess Plateau. The fertilizer treatments were found to decrease the soil water content more than the NF treatment in each of the growing seasons. The annual average yields of the field pea crops during the entire experimental period were 635, 677, 858, and 1117 kg/ha for the NF, N, P, and NP treatments, respectively. The annual average yields were 673, 547, 966, and 1056 kg/ha for the spring wheat crops for the NF, N, P, and NP treatments, respectively. Also, the annual average yields were 1476, 2120, 1480, and 2424 kg/ha for the potato crops for the NF, N, P, and NP treatments, respectively. In the second cycle of the three-year rotation, the pea and spring wheat yields in the P treatment were 1.2 and 2.8 times higher than that in the N treatment, respectively. Meanwhile, the potato crop yield in the N treatment was 3.1 times higher than that in the P treatment. In conclusion, the P fertilizer was found to increase the yields of the field pea and wheat crops, and the N fertilizer increased the potato crop yield in rainfed areas with calcareous soil.

  19. Effects of nitrogen and phosphorus fertilizer on crop yields in a field pea-spring wheat-potato rotation system with calcareous soil in semi-arid environments

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.A.; Zhang, S.; Hua, S.; Rao, X.

    2016-11-01

    The object of the present study was to investigate the yield-affecting mechanisms influenced by N and P applications in rainfed areas with calcareous soil. The experimental treatments were as follows: NF (no fertilizer), N (nitrogen), P (phosphorus), and NP (nitrogen plus phosphorus) in a field pea-spring wheat-potato cropping system. This study was conducted over six years (2003-2008) on China’s semi-arid Loess Plateau. The fertilizer treatments were found to decrease the soil water content more than the NF treatment in each of the growing seasons. The annual average yields of the field pea crops during the entire experimental period were 635, 677, 858, and 1117 kg/ha for the NF, N, P, and NP treatments, respectively. The annual average yields were 673, 547, 966, and 1056 kg/ha for the spring wheat crops for the NF, N, P, and NP treatments, respectively. Also, the annual average yields were 1476, 2120, 1480, and 2424 kg/ha for the potato crops for the NF, N, P, and NP treatments, respectively. In the second cycle of the three-year rotation, the pea and spring wheat yields in the P treatment were 1.2 and 2.8 times higher than that in the N treatment, respectively. Meanwhile, the potato crop yield in the N treatment was 3.1 times higher than that in the P treatment. In conclusion, the P fertilizer was found to increase the yields of the field pea and wheat crops, and the N fertilizer increased the potato crop yield in rainfed areas with calcareous soil. (Author)

  20. Electronic density measurement in the TB R-1 tokamak using Faraday rotation

    International Nuclear Information System (INIS)

    Elizondo, Juan Iraburu

    1996-01-01

    In this work, the experimental results of electronic density measurements in the TBR-1 tokamak, obtained by Faraday rotation of a microwave beam, are presented, The beam (65 GHz, 500 MW) is generated by a Klystron and crosses the plasma in the horizontal plane. The density values obtained are in agreement with the measurements of a conventional microwave interferometer. As a result of numerical simulations and measurements, it can be concluded that it would be advisable the use of lower wavelengths, to minimize the beam refraction when it crosses the plasma. The results show the feasibility of the Faraday rotation method for density measurement, in the first experiment performed in a tokamak, for the geometry considered. (author)

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    rotation of annual crops (maize, beet, hemp/oat, triticale, winter rye and winter rapeseed), ii) perennial crops intensively fertilised (festulolium, reed canary, cocksfoot and tall fescue), low-fertilised (miscanthus) or unfertilised (grass-legume mixtures) and iii) traditional systems (continuous...

  2. Direct use of phosphate rock to improve crop production in Indonesia

    International Nuclear Information System (INIS)

    Sisworo, E.L.; Rasjid, H.; Sisworo, W.H.; Haryanto; Idris, K.

    2002-01-01

    In Indonesia most of the areas left for producing crops have soils such as Ultisols and Oxisols that are highly weathered, acid and of low fertility. One of the main constraints is their low available P to support food crop production. P inputs such as inorganic fertilizers, organic matter, and phosphate rock (PR) must be applied. Phosphate rock is one of the options for farmers to use as a P-source for food crops. In the frame of the coordinated research program three pot and five field experiments were conducted to determine the agronomic effectiveness of PR for food crops using 32 P isotopic techniques. Crops used in the pot experiments were lowland rice, soybean, and mungbean. One of the pot experiments was a crop rotation simulation where upland rice, soybean, and mungbean were grown in sequence. Two of the field experiments were a crop rotation of upland rice, soybean, and mungbean. In the field experiments, 32 P was used to determine the agronomic effectiveness, whenever possible. In general, the direct application of PR was able to increase plant growth in the pot experiments and crop production in the field experiments. Use of 32 P was a good tool to determine the agronomic effectiveness of PR in the pot and field experiments. (author)

  3. A Medipix quantum area detector allows rotation electron diffraction data collection from submicrometre three-dimensional protein crystals

    Energy Technology Data Exchange (ETDEWEB)

    Nederlof, Igor; Genderen, Eric van; Li, Yao-Wang; Abrahams, Jan Pieter, E-mail: abrahams@chem.leidenuniv.nl [Leiden University, Einsteinweg 55, 2333 CC Leiden (Netherlands)

    2013-07-01

    An ultrasensitive Medipix2 detector allowed the collection of rotation electron-diffraction data from single three-dimensional protein nanocrystals for the first time. The data could be analysed using the standard X-ray crystallography programs MOSFLM and SCALA. When protein crystals are submicrometre-sized, X-ray radiation damage precludes conventional diffraction data collection. For crystals that are of the order of 100 nm in size, at best only single-shot diffraction patterns can be collected and rotation data collection has not been possible, irrespective of the diffraction technique used. Here, it is shown that at a very low electron dose (at most 0.1 e{sup −} Å{sup −2}), a Medipix2 quantum area detector is sufficiently sensitive to allow the collection of a 30-frame rotation series of 200 keV electron-diffraction data from a single ∼100 nm thick protein crystal. A highly parallel 200 keV electron beam (λ = 0.025 Å) allowed observation of the curvature of the Ewald sphere at low resolution, indicating a combined mosaic spread/beam divergence of at most 0.4°. This result shows that volumes of crystal with low mosaicity can be pinpointed in electron diffraction. It is also shown that strategies and data-analysis software (MOSFLM and SCALA) from X-ray protein crystallography can be used in principle for analysing electron-diffraction data from three-dimensional nanocrystals of proteins.

  4. Effect of the moment of inertia of an electron shell on the rotational g factor of a molecule

    International Nuclear Information System (INIS)

    Rebane, T.K.

    1988-01-01

    It is noted that electron currents induced by the rotation of a molecule make a contribution not only to the magnetic moment, but also to the angular momentum of a molecule and to its moment of inertia. An improved equation for the rotational g factor of a molecule, allowing for the contribution of electrons to the moment of inertia, is given. The B 1 summation + /sub u/ excited electronic state of the hydrogen molecule is used as an example to show that the electronic contribution to the moment of inertia amounts to 0.3 to 0.5% (for H 2 and D 2 molecules, respectively) of the value of the nuclear contribution, and its consideration in calculations of g factors is obligatory

  5. Soil microbiome characteristics and soilborne disease development associated with long-term potato cropping system practices

    Science.gov (United States)

    Potato cropping system practices substantially affect soil microbial communities and the development of soilborne diseases. Cropping systems incorporating soil health management practices, such as longer rotations, disease-suppressive crops, reduced tillage, and/or organic amendments can potentially...

  6. New indicators for global crop monitoring in CropWatch -case study in North China Plain

    International Nuclear Information System (INIS)

    Bingfang, Wu; Miao, Zhang; Hongwei, Zeng; Guoshui, Liu; Sheng, Chang; Gommes, René

    2014-01-01

    CropWatch is a monitoring system developed and operated by the Institute of Remote Sensing and Digital Earth (Chinese Academy of Sciences) to provide global-scale crop information. Now in its 15th year of operation, CropWatch was modified several times to be a timely, comprehensive and independent global agricultural monitoring system using advanced remote sensing technology. Currently CropWatch is being upgraded with new indicators based on new sensors, especially those on board of China Environmental Satellite (HJ-1 CCD), the Medium Resolution Spectral Imager (MERSI) on Chinese meteorological satellite (FY-3A) and cloud classification products of FY-2. With new satellite data, CropWatch will generate new indicators such as fallow land ratio (FLR), crop condition for irrigated (CCI) and non-irrigated (CCNI) areas separately, photosynthetically active radiation (PAR), radiation use efficiency for the photosynthetically active radiation (RUE PAR ) and cropping index (CI) with crop rotation information (CRI). In this paper, the methods for monitoring the new indicators are applied to the North China Plain which is one of the major grain producing areas in China. This paper shows the preliminary results of the new indicators and methods; they still need to be thoroughly validated before being incorporated into the operational CropWatch system. In the future, the new and improved indicators will help us to better understand the global situation of food security

  7. Rice production in relation to soil quality under different rice-based cropping systems

    Science.gov (United States)

    Tran Ba, Linh; Sleutel, Steven; Nguyen Van, Qui; Thi, Guong Vo; Le Van, Khoa; Cornelis, Wim

    2016-04-01

    Soil quality of shallow paddy soils may be improved by introducing upland crops and thus a more diverse crop cultivation pattern. Yet, the causal relationship between crop performance and enhanced soil traits in rice-upland crop rotations remains elusive. The objectives of this study were to (i) find correlations among soil properties under different rice-upland crop systems and link selected soil properties to rice growth and yield, (ii) present appropriate values of soil parameters for sustainable rice productivity in heavy clay soil, (iii) evaluate the effect of rotating rice with upland crops on rice yield and economic benefit in a long-term experiment. A rice-upland crop rotational field experiment in the Vietnamese Mekong delta was conducted for 10 years using a randomized complete block design with four treatments and four replications. Treatments were: (i) rice-rice-rice (control - conventional system as farmers' practice), (ii) rice-maize-rice, (iii) rice-mung bean-rice, and (iv) rice-mung bean-maize. Soil and plant sampling were performed after harvest of the rice crop at the end of the final winter-spring cropping season (i.e. year 10). Results show differences in rice growth and yield, and economic benefit as an effect of the crop rotation system. These differences were linked with changes in bulk density, soil porosity, soil aggregate stability index, soil penetration resistance, soil macro-porosity, soil organic carbon, acid hydrolysable soil C and soil nutrient elements, especially at soil depth of 20-30 cm. This is evidenced by the strong correlation (P < 0.01) between rice plant parameters, rice yield and soil properties such as bulk density, porosity, penetration resistance, soil organic carbon and Chydrolysable. It turned out that good rice root growth and rice yield corresponded to bulk density values lower than 1.3 Mg m-3, soil porosity higher than 50%, penetration resistance below 1.0 MPa, and soil organic carbon above 25 g kg-1. The optimal

  8. Reduction of the Glauber amplitude for electron impact rotational excitation of quadrupolar molecular ions

    International Nuclear Information System (INIS)

    Mathur, K.C.; Gupta, G.P.; Pundir, R.S.

    1981-06-01

    A reduction of the Glauber amplitude for the rotational excitation of pure quadrupolar molecular ions by electron impact is presented in a form suitable for numerical evaluation. The differential cross-section is expressed in terms of one dimensional integrals over impact parameter. (author)

  9. Electronically rotated and translated field-free line generation for open bore magnetic particle imaging.

    Science.gov (United States)

    Top, Can Barış; Ilbey, Serhat; Güven, Hüseyin Emre

    2017-12-01

    We propose a coil arrangement for open bore field-free line (FFL) magnetic particle imaging (MPI) system, which is suitable for accessing the subject from the sides. The purpose of this study is twofold, to show that the FFL can be rotated and translated electronically in a volume of interest with this arrangement and to analyze the current, voltage and power requirements for a 1 T/m gradient human sized scanner for a 200 mm diameter × 200 mm height cylindrical field of view (FOV). We used split coils side by side with alternating current directions to generate a field-free line. Employing two of these coil groups, one of which is rotated 90 degrees with respect to the other, a rotating FFL was generated. We conducted numerical simulations to show the feasibility of this arrangement for three-dimensional (3D) electronical scan of the FFL. Using simulations, we obtained images of a two-dimensional (2D) in silico dot phantom for a human size scanner with system matrix-based reconstruction. Simulations showed that the FFL can be generated and rotated in one plane and can be translated in two axes, allowing for 3D imaging of a large subject with the proposed arrangement. Human sized scanner required 63-215 kW power for the selection field coils to scan the focus inside the FOV. The proposed setup is suitable for FFL MPI imaging with an open bore configuration without the need for mechanical rotation, which is preferable for clinical usage in terms of imaging time and patient access. Further studies are necessary to determine the limitations imposed by peripheral nerve stimulation, and to optimize the system parameters and the sequence design. © 2017 American Association of Physicists in Medicine.

  10. Limited Impact of a Fall-Seeded, Spring-Terminated Rye Cover Crop on Beneficial Arthropods.

    Science.gov (United States)

    Dunbar, Mike W; Gassmann, Aaron J; O'Neal, Matthew E

    2017-04-01

    Cover crops are beneficial to agroecosystems because they decrease soil erosion and nutrient loss while increasing within-field plant diversity. Greater plant diversity within cropping systems can positively affect beneficial arthropod communities. We hypothesized that increasing plant diversity within annually rotated corn and soybean with the addition of a rye cover crop would positively affect the beneficial ground and canopy-dwelling communities compared with rotated corn and soybean grown without a cover crop. From 2011 through 2013, arthropod communities were measured at two locations in Iowa four times throughout each growing season. Pitfall traps were used to sample ground-dwelling arthropods within the corn and soybean plots and sweep nets were used to measure the beneficial arthropods in soybean canopies. Beneficial arthropods captured were identified to either class, order, or family. In both corn and soybean, community composition and total community activity density and abundance did not differ between plots that included the rye cover crop and plots without the rye cover crop. Most taxa did not significantly respond to the presence of the rye cover crop when analyzed individually, with the exceptions of Carabidae and Gryllidae sampled from soybean pitfall traps. Activity density of Carabidae was significantly greater in soybean plots that included a rye cover crop, while activity density of Gryllidae was significantly reduced in plots with the rye cover crop. Although a rye cover crop may be agronomically beneficial, there may be only limited effects on beneficial arthropods when added within an annual rotation of corn and soybean. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Earthworm populations are affected from Long-Term Crop Sequences and Bio-Covers under No-Tillage

    Science.gov (United States)

    Earthworms are crucial for improving soil biophysical properties in cropping systems. Consequently, effects of cropping rotation and bio-covers were assessed on earthworm populations under no-tillage sites. Main effects of 6 different cropping sequences [corn (Zea mays), cotton (Gossypium hirsutum),...

  12. Direct use of phosphate rock to improve crop production in Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Sisworo, E L; Rasjid, H; Sisworo, W H; Haryanto, [Batan, Center for the application of isotopes and radiation, Jakarta (Indonesia); Idris, K [Bogor Agriculture Institute, Bogor (Indonesia)

    2002-02-01

    In Indonesia most of the areas left for producing crops have soils such as Ultisols and Oxisols that are highly weathered, acid and of low fertility. One of the main constraints is their low available P to support food crop production. P inputs such as inorganic fertilizers, organic matter, and phosphate rock (PR) must be applied. Phosphate rock is one of the options for farmers to use as a P-source for food crops. In the frame of the coordinated research program three pot and five field experiments were conducted to determine the agronomic effectiveness of PR for food crops using {sup 32}P isotopic techniques. Crops used in the pot experiments were lowland rice, soybean, and mungbean. One of the pot experiments was a crop rotation simulation where upland rice, soybean, and mungbean were grown in sequence. Two of the field experiments were a crop rotation of upland rice, soybean, and mungbean. In the field experiments, {sup 32}P was used to determine the agronomic effectiveness, whenever possible. In general, the direct application of PR was able to increase plant growth in the pot experiments and crop production in the field experiments. Use of {sup 32}P was a good tool to determine the agronomic effectiveness of PR in the pot and field experiments. (author)

  13. Climate Impacts of Cover Crops

    Science.gov (United States)

    Lombardozzi, D.; Wieder, W. R.; Bonan, G. B.; Morris, C. K.; Grandy, S.

    2016-12-01

    Cover crops are planted in agricultural rotation with the intention of protecting soil rather than harvest. Cover crops have numerous environmental benefits that include preventing soil erosion, increasing soil fertility, and providing weed and pest control- among others. In addition to localized environmental benefits, cover crops can have important regional or global biogeochemical impacts by increasing soil organic carbon, changing emissions of greenhouse trace gases like nitrous oxide and methane, and reducing hydrologic nitrogen losses. Cover crops may additionally affect climate by changing biogeophysical processes, like albedo and latent heat flux, though these potential changes have not yet been evaluated. Here we use the coupled Community Atmosphere Model (CAM5) - Community Land Model (CLM4.5) to test how planting cover crops in the United States may change biogeophysical fluxes and climate. We present seasonal changes in albedo, heat fluxes, evaporative partitioning, radiation, and the resulting changes in temperature. Preliminary analyses show that during seasons when cover crops are planted, latent heat flux increases and albedo decreases, changing the evaporative fraction and surface temperatures. Understanding both the biogeophysical changes caused by planting cover crops in this study and the biogeochemical changes found in other studies will give a clearer picture of the overall impacts of cover crops on climate and atmospheric chemistry, informing how this land use strategy will impact climate in the future.

  14. Impacts of Cover Crops on Water and Nutrient Dynamics in Agroecosystems

    Science.gov (United States)

    Williard, K.; Swanberg, S.; Schoonover, J.

    2013-05-01

    Intensive cropping systems of corn (Zea Mays L.) and soybeans (Glycine max) are commonly leaky systems with respect to nitrogen (N). Reactive N outputs from agroecosystems can contribute to eutrophication and hypoxic zones in downstream water bodies and greenhouse gas (N2O) emissions. Incorporating cover crops into temperate agroecosystem rotations has been promoted as a tool to increase nitrogen use efficiency and thus limit reactive N outputs to the environment. Our objective was determine how cereal rye (Secale cereal L.) and annual ryegrass (Lolium multiflorum) cover crops impact nutrient and soil water dynamics in an intensive corn and soybean cropping rotation in central Illinois. Cover crops were planted in mid to late October and terminated in early April prior to corn or soybean planting. In the spring just prior to cover crop termination, soil moisture levels were lower in the cover crop plots compared to no cover plots. This can be a concern for the subsequent crop in relatively dry years, which the Midwestern United States experienced in 2012. No cover plots had greater nutrient leaching below the rooting zone compared to cover crop areas, as expected. The cover crops were likely scavenging nutrients during the fall and early spring and should provide nutrients to the subsequent crop via decomposition and mineralization of the cover crop residue. Over the long term, cover crop systems should produce greater inputs and cycling of carbon and N, increasing the productivity of crops due to the long-term accumulation of soil organic matter. This study demonstrates that there may be short term trade-offs in reduced soil moisture levels that should be considered alongside the long term nutrient scavenging and recycling benefits of cover crops.

  15. Electronic structure of the rotation twin stacking fault in β-ZnS

    International Nuclear Information System (INIS)

    Northrup, J.E.; Cohen, M.L.

    1981-01-01

    The electronic structure of the rotation twin stacking fault in β-ZnS is calculated with the self-consistent pseudopotential method. The stacking fault creates a potential barrier of approx.0.07 eV and induces the localization of stacking-fault resonances near the top of the valence band. Stacking-fault states are also predicted to exist in the various gaps in the projected valence-band structure

  16. Managing for Multifunctionality in Perennial Grain Crops

    Science.gov (United States)

    Ryan, Matthew R; Crews, Timothy E; Culman, Steven W; DeHaan, Lee R; Hayes, Richard C; Jungers, Jacob M; Bakker, Matthew G

    2018-01-01

    Abstract Plant breeders are increasing yields and improving agronomic traits in several perennial grain crops, the first of which is now being incorporated into commercial food products. Integration strategies and management guidelines are needed to optimize production of these new crops, which differ substantially from both annual grain crops and perennial forages. To offset relatively low grain yields, perennial grain cropping systems should be multifunctional. Growing perennial grains for several years to regenerate soil health before rotating to annual crops and growing perennial grains on sloped land and ecologically sensitive areas to reduce soil erosion and nutrient losses are two strategies that can provide ecosystem services and support multifunctionality. Several perennial cereals can be used to produce both grain and forage, and these dual-purpose crops can be intercropped with legumes for additional benefits. Highly diverse perennial grain polycultures can further enhance ecosystem services, but increased management complexity might limit their adoption. PMID:29662249

  17. Nitrogen supply and demand in short-rotation sweetgum plantations

    Science.gov (United States)

    D. Andrew Scott; James A. Burger; Donald J. Kaczmarek; Michael B. Kane

    2004-01-01

    Intensive management is crucial for optimizing hardwood plantation success, and nitrogen (N) nutrition management is one of the most important practices in intensive management. Because management of short-rotation woody crop plantations is a mixture of row-crop agriculture and plantation forestry, we tested the usefulness of an agronomic budget modified for deciduous...

  18. Cropping system impact on soil quality determinants

    Directory of Open Access Journals (Sweden)

    M. VESTBERG

    2008-12-01

    Full Text Available Worldwide interest in soil quality evaluation has increased rapidly throughout the past decade, prompting us to evaluate the long-term impact of four cropping systems on several biological, chemical and physical determinants of soil quality. We hypothesized that after 17 years several of the determinants would show significant differences between conventional cereal and low input/organic rotations. Four crop rotations were imposed on a silt soil from 1982 through 1999. Rotation A was a conventionally managed cereal rotation that received 100% of the recommended mineral fertilizer each year. Rotation B was also managed conventionally from 1982 until 1993, although it received only 50% of the recommended mineral fertilizer. From 1994 through 1999, rotation B was managed as an organic rotation. Rotations C and D were low-input rotations with plant residues returned either untreated (Cor composted (Dfrom 1982 until 1994.From 1994 through 1999,they were also anaged organically. Significant decreases in extractable phosphorus (Pand potassium were observed in rotations C and D compared with rotation A, presumably because their yearly nutrient inputs were somewhat lower. The amount of soil organic carbon (Corg, soil water holding capacity, the numbers and biomass of earthworms and the microbial biomass carbon and nitrogen were or tended to be higher in low input/organic than in conventionally managed plots. These effects may be in connection with the slightly increased levels of Corg in soil of the organic rotations. Activities of twelve enzymes were strongly affected by sampling time (early-versus late-summer, but much less by long-term management. Litter decomposition, numbers of soil nematodes, arbuscular mycorrhizal (AMfungal diversity,AM spore density and AM functioning were little affected by rotation. However,AM spore density correlated positively with the high amounts of extractable calcium and P which were a result from excessive liming applied

  19. Remote Sensing and Cropping Practices: A Review

    Directory of Open Access Journals (Sweden)

    Agnès Bégué

    2018-01-01

    Full Text Available For agronomic, environmental, and economic reasons, the need for spatialized information about agricultural practices is expected to rapidly increase. In this context, we reviewed the literature on remote sensing for mapping cropping practices. The reviewed studies were grouped into three categories of practices: crop succession (crop rotation and fallowing, cropping pattern (single tree crop planting pattern, sequential cropping, and intercropping/agroforestry, and cropping techniques (irrigation, soil tillage, harvest and post-harvest practices, crop varieties, and agro-ecological infrastructures. We observed that the majority of the studies were exploratory investigations, tested on a local scale with a high dependence on ground data, and used only one type of remote sensing sensor. Furthermore, to be correctly implemented, most of the methods relied heavily on local knowledge on the management practices, the environment, and the biological material. These limitations point to future research directions, such as the use of land stratification, multi-sensor data combination, and expert knowledge-driven methods. Finally, the new spatial technologies, and particularly the Sentinel constellation, are expected to improve the monitoring of cropping practices in the challenging context of food security and better management of agro-environmental issues.

  20. Environmental effectiveness of GAEC cross-compliance standard 2.2 "Maintaining the level of soil organic matter through crop rotation" and economic evaluation of the competitiveness gap for farmers

    Directory of Open Access Journals (Sweden)

    Lamberto Borrelli

    2015-11-01

    Full Text Available Within the Project MO.NA.CO was evaluated the Environmental effectiveness of GAEC cross-compliance standard 2.2 “Maintaining the level of soil organic matter through crop rotation” and economic evaluation of the competitiveness gap for farmers who support or not the cross-compliance regime. The monitoring was performed in nine experimental farms of the Council for Agricultural Research and Economics (CREA distributed throughout Italy and with different soil and climatic conditions. Were also evaluated the soil organic matter and some yield parameters, in a cereal monocropping (treatment counterfactual and a two-year rotation cereal-legume or forage (treatment factual. The two-years application of the standard “crop rotations” has produced contrasting results with regards to the storage of soil organic matter through crop rotation and these were not sufficient to demonstrate a statistically significant effect of treatment in any of the farms considered in monitoring, only in those farms subjected to more years of monitoring was recorded only a slight effect of the standard as a trend. The variations of organic matter in soils in response to changes in the culture technique or in the management of the soil may have long lag times and two years of time are not sufficient to demonstrate the dynamics of SOM associated with the treatment, also in consideration of the large inter annual variability recorded in different monitored sites.

  1. European Perspectives on the Adoption of Non-Chemical Weed Management in Reduced Tillage Systems for Arable Crops

    DEFF Research Database (Denmark)

    Melander, B.; Munier-Jolan, N.; Schwarz, J.

    2012-01-01

    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...

  2. [Soil quality assessment under different cropping system and straw management in farmland of arid oasis region].

    Science.gov (United States)

    Zhang, Peng Peng; Pu, Xiao Zhen; Zhang, Wang Feng

    2018-03-01

    To reveal the regulatory mechanism of agricultural management practices on soil quality, an experiment was carried out to study the different cropping system and straw management on soil organic carbon and fractions and soil enzyme activity in farmland of arid oasis region, which would provide a scientific basic for enhancing agricultural resources utilization and sustainable development. In crop planting planning area, we took the mainly crop (cotton, wheat, maize) as research objects and designed long-term continues cropping and crop rotation experiments. The results showed that the soil organic carbon (SOC), soil microbial biomass C, labile C, water-soluble organic C, and hot-water-soluble organic C content were increased by 3.6%-9.9%, 41.8%-98.9%, 3.3%-17.0%, 11.1%-32.4%, 4.6%-27.5% by crop rotation compared to continues cropping, and 12%-35.9%, 22.4%-49.7%, 30.7%-51.0%, 10.6%-31.9%, 41.0%-96.4% by straw incorporated compared to straw removed, respectively. The soil catalase, dehydrogenase, β-glucosidase, invertase glucose, cellulase glucose activity were increased by 6.4%-10.9%, 6.6%-18.8%, 5.9%-15.3%, 10.0%-27.4%, 28.1%-37.5% by crop rotation compared to continues cropping, and 31.4%-47.5%, 19.9%-46.6%, 13.8%-20.7%, 19.8%-55.6%, 54.1%-70.9% by straw incorporated compared to straw removed, respectively. There were significant positive linear correlations among SOC, labile SOC fractions and soil enzyme. Therefore, we concluded that labile SOC fractions and soil enzyme were effective index for evaluating the change of SOC and soil quality. Based on factor analysis, in arid region, developing agricultural production using cropland management measures, such as straw-incorporated and combined short-term continues cotton and crop rotation, could enhance SOC and labile SOC fractions contents and soil enzyme activity, which could improve soil quality and be conducive to agricultural sustainable development.

  3. Femtosecond single electron bunch generation by rotating longitudinal bunch phase space in magnetic field

    International Nuclear Information System (INIS)

    Yang, J.; Kondoh, T.; Kan, K.; Kozawa, T.; Yoshida, Y.; Tagawa, S.

    2006-01-01

    A femtosecond (fs) electron bunching was observed in a photoinjector with a magnetic compressor by rotating the bunch in longitudinal phase space. The bunch length was obtained by measuring Cherenkov radiation of the electron beam with a femtosecond streak camera technique. A single electron bunch with rms bunch length of 98 fs was observed for a 32 MeV electron beam at a charge of 0.17 nC. The relative energy spread and the normalized transverse emittance of the electron beam were 0.2% and 3.8 mm-mrad, respectively. The effect of space charge on the bunch compression was investigated experimentally for charges from 0.17 to 1.25 nC. The dependences of the relative energy spread and the normalized beam transverse emittance on the bunch charge were measured

  4. Contribution of Legume Rotations to the Nitrogen Requirements of a ...

    African Journals Online (AJOL)

    Industrial fertilizers are expensive for small-scale farmers who, as alternative, rely on legume crops for providing N for a subsequent maize crop. A legume-maize rotational experiment was carried out on a Rhodic Ferralsol at Mlingano Agricultural Research Institute in Muheza, Tanga, Tanzania, to evaluate the effects of ...

  5. Overall assessment of soil quality on humid sandy loams: Effects of location, rotation and tillage

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Hansen, Elly Møller; Rickson, J.M.

    2015-01-01

    .e. visual evaluation of soil structure (VESS), overall visual structure (OVS) and overall soil structure (OSS)) were employed to differentiate the effects of these alternative management practices on soil structural quality and relative crop yield (RY). A Pearson correlation was also employed to find...... the correlation between the soil quality indices and relative crop yield. Relevant soil properties for calculating the soil quality indices were measured or obtained from previous publications. Crop rotation affected the soil structure and RY. The winter-dominated crop rotation (R2) resulted in the poorest soil...... correlations were found in most cases between soil quality indices (including M-SQR) and RY. This highlights the influence of soil quality (as measured by the selected indicators) – and soil structure in particular – on crop yield potential....

  6. Biomass supply from alternative cellulosic crops and crop residues: A spatially explicit bioeconomic modeling approach

    International Nuclear Information System (INIS)

    Egbendewe-Mondzozo, Aklesso; Swinton, Scott M.; Izaurralde, César R.; Manowitz, David H.; Zhang, Xuesong

    2011-01-01

    This paper introduces a spatially-explicit bioeconomic model for the study of potential cellulosic biomass supply. For biomass crops to begin to replace current crops, farmers must earn more from them than from current crops. Using weather, topographic and soil data, the terrestrial ecosystem model, EPIC, dynamically simulates multiple cropping systems that vary by crop rotation, tillage, fertilization and residue removal rate. EPIC generates predicted crop yield and environmental outcomes over multiple watersheds. These EPIC results are used to parameterize a regional profit-maximization mathematical programming model that identifies profitable cropping system choices. The bioeconomic model is calibrated to 2007–09 crop production in a 9-county region of southwest Michigan. A simulation of biomass supply in response to rising biomass prices shows that cellulosic residues from corn stover and wheat straw begin to be supplied at minimum delivered biomass:corn grain price ratios of 0.15 and 0.18, respectively. At the mean corn price of $162.6/Mg ($4.13 per bushel) at commercial moisture content during 2007–2009, these ratios correspond to stover and straw prices of $24 and $29 per dry Mg. Perennial bioenergy crops begin to be supplied at price levels 2–3 times higher. Average biomass transport costs to the biorefinery plant range from $6 to $20/Mg compared to conventional crop production practices in the area, biomass supply from annual crop residues increased greenhouse gas emissions and reduced water quality through increased nutrient loss. By contrast, perennial cellulosic biomass crop production reduced greenhouse gas emissions and improved water quality. -- Highlights: ► A new bioeconomic model predicts biomass supply and its environmental impacts. ► The model captures the opportunity cost of switching to new cellulosic crops. ► Biomass from crop residues is supplied at lower biomass price than cellulosic crops. ► Biomass from cellulosic crops has

  7. The role of rotational mechanisms in electron swarm parameters at low reduced electric field in N2, O2 and H2

    International Nuclear Information System (INIS)

    Ridenti, M A; Amorim, J; Alves, L L; Guerra, V

    2015-01-01

    The homogeneous Boltzmann equation for electrons in N 2 , O 2 and H 2 is solved under the classical two-term approximation, for reduced electric fields in the interval 10   −  4   −10 Td where the electron-neutral encounters are limited to elastic, rotational and vibrational collisions. Rotational excitations/de-excitations are described using the following three different approaches: the discrete inelastic/superelastic collisional operator, written for a number of rotational levels that depends on the molecular gas and the specific rotational cross sections considered; the continuous approximation for rotations; a modified version of the continuous approximation for rotations, including a Chapman–Cowling corrective term proportional to the gas temperature. The expression of the rotational collision operator for this latter approach is deduced here and the results show that it bridges the gap between the discrete and the continuous descriptions at low/intermediate reduced electric fields. The calculations are compared with the measurements for the available swarm parameters to assess the validity of the different approaches and cross sections adopted to describe the rotational mechanisms. (paper)

  8. Canola-Wheat Rotation versus Continuous Wheat for the Southern Plains

    OpenAIRE

    Duke, Jason C.; Epplin, Francis M.; Vitale, Jeffrey D.; Peeper, Thomas F.

    2009-01-01

    Crop rotations are not common in the wheat belt of the Southern Plains. After years of continuous wheat, weeds have become increasingly difficult and expensive to manage. Yield data were elicited from farmers and used to determine if canola-wheat-wheat rotations are economically competitive with continuous wheat in the region.

  9. Nitrogen effects on maize yield following groundnut in rotation on ...

    African Journals Online (AJOL)

    Rotating maize (Zea mays L.) with groundnut (Arachis hypogaea L.) has been proposed as a way to maintain soil fertility and prevent maize productivity declines in the smallholder cropping systems of sub-humid Zimbabwe. Field experiments with fertilizer-N on maize in rotation with groundnut were conducted at three ...

  10. Energy crops for biogas plants. Brandenburg; Energiepflanzen fuer Biogasanlagen. Brandenburg

    Energy Technology Data Exchange (ETDEWEB)

    Adam, L.; Barthelmes, G.; Biertuempfel, A. (and others)

    2012-06-15

    In the brochure under consideration, the Agency for Renewable Resources (Guelzen-Pruezen, Federal Republic of Germany) reported on recommendations on alternative cropping systems for energy crop rotations in order to achieve high yields in combination with high diversity, risk spreading and sustainability. In particular, the natural site conditions in the Federal State of Brandenburg (Federal Republic of Germany) are determined.

  11. Quantum-mechanical theory for electronic-vibrational-rotational energy transfer in atom--diatom collisions: Analysis of the Hamiltonian

    International Nuclear Information System (INIS)

    Bellum, J.C.; McGuire, P.

    1983-01-01

    We investigate forms of the molecular system Hamiltonian valid for rigorous quantum-mechanical treatments of inelastic atom--diatom collisions characterized by exchange of energy between electronic, vibrational, and rotational degrees of freedom. We analyze this Hamiltonian in terms of various choices of independent coordinates which unambiguously specify the electronic and nuclear positions in the context of space-fixed and body-fixed reference frames. In particular we derive forms of the Hamiltonian in the context of the following four sets of independent coordinates: (1) a so-called space-fixed set, in which both electronic and nuclear positions are relative to the space-fixed frame; (2) a so-called mixed set, in which nuclear positions are relative to the body-fixed frame while electronic positions are relative to the space-fixed frame; (3) a so-called body-fixed set, in which both electronic and nuclear positions are relative to the body-fixed frame; and (4) another mixed set, in which nuclear positions are relative to the space-fixed frame while electronic positions are relative to the body-fixed frame. Based on practical considerations in accounting for electronic structure and nonadiabatic coupling of electronic states of the collision complex we find the forms of the Hamiltonian in the context of coordinate sets (3) and (4) above to be most appropriate, respectively, for body-fixed and space-fixed treatments of nuclear dynamics in collisional transfer of electronic, vibrational, and rotational energies

  12. Effect of integrated forage rotation and manure management on yield, nutrient balance and soil organic matter

    Directory of Open Access Journals (Sweden)

    Cesare Tomasoni

    2011-03-01

    Full Text Available This paper reports results from a field experiment established in 1995 and still on going. It is located in Lodi, in the irrigated lowlands of Lombardy, Northern Italy. The experiment compares two rotations: the annual double cropping system, Italian ryegrass + silage maize (R1; and the 6-year rotation, in which three years of double crop Italian ryegrass + silage maize are followed by three years of alfalfa harvested for hay (R6 Each rotation have received two types of dairy manure: i farmyard manure (FYM; ii semi-liquid manure (SLM. The intent was to apply to each unit land area the excreta produced by the number of adult dairy cows sustained, in terms of net energy, by the forage produced in each rotation, corresponding to about 6 adult cows ha-1 for R1 and 4 adult cows ha-1 for R6. Manure was applied with (N1 or without (N0 an extra supply of mineral N in the form of urea. The objectives of this study were: i to assess whether the recycling of two types of manure in two forage rotation systems can sustain crop yields in the medium and long term without additional N fertilization; ii to evaluate the nutrient balance of these integrated forage rotations and manure management systems; iii to compare the effects of farmyard manure and semi-liquid manure on soil organic matter. The application of FYM, compared to SLM, increased yield of silage maize by 19% and alfalfa by 23%, while Italian ryegrass was not influenced by the manure treatment. Yet, silage maize produced 6% more in rotation R6 compared to rotation R1. The mineral nitrogen fertilization increased yield of Italian ryegrass by 11% and of silage maize by 10%. Alfalfa, not directly fertilized with mineral nitrogen, was not influenced by the nitrogen applied to the other crops in rotation. The application of FYM, compared to SLM, increased soil organic matter (SOM by +37 % for the rotation R1, and by +20% for the rotation R6. Conversely, no significant difference on SOM was observed

  13. Rotational spectroscopy with an optical centrifuge.

    Science.gov (United States)

    Korobenko, Aleksey; Milner, Alexander A; Hepburn, John W; Milner, Valery

    2014-03-07

    We demonstrate a new spectroscopic method for studying electronic transitions in molecules with extremely broad range of angular momentum. We employ an optical centrifuge to create narrow rotational wave packets in the ground electronic state of (16)O2. Using the technique of resonance-enhanced multi-photon ionization, we record the spectrum of multiple ro-vibrational transitions between X(3)Σg(-) and C(3)Πg electronic manifolds of oxygen. Direct control of rotational excitation, extending to rotational quantum numbers as high as N ≳ 120, enables us to interpret the complex structure of rotational spectra of C(3)Πg beyond thermally accessible levels.

  14. PGOPHER: A program for simulating rotational, vibrational and electronic spectra

    Science.gov (United States)

    Western, Colin M.

    2017-01-01

    The PGOPHER program is a general purpose program for simulating and fitting molecular spectra, particularly the rotational structure. The current version can handle linear molecules, symmetric tops and asymmetric tops and many possible transitions, both allowed and forbidden, including multiphoton and Raman spectra in addition to the common electric dipole absorptions. Many different interactions can be included in the calculation, including those arising from electron and nuclear spin, and external electric and magnetic fields. Multiple states and interactions between them can also be accounted for, limited only by available memory. Fitting of experimental data can be to line positions (in many common formats), intensities or band contours and the parameters determined can be level populations as well as rotational constants. PGOPHER is provided with a powerful and flexible graphical user interface to simplify many of the tasks required in simulating, understanding and fitting molecular spectra, including Fortrat diagrams and energy level plots in addition to overlaying experimental and simulated spectra. The program is open source, and can be compiled with open source tools. This paper provides a formal description of the operation of version 9.1.

  15. Containment of the western corn rootworm Diabrotica v.virgifera: continued successful management 2008 in southern Switzerland by monitoring and crop rotation.

    Science.gov (United States)

    Hummel, Hans E; Bertossa, M

    2009-01-01

    Diabrotica virgifera virgifera LeConte (Col.: Chrysomelidae), known as western corn rootworm (WCR) and endemic in North America, invaded Europe about two decades ago. Various unsuccessful attempts have been made to eradicate it from the Old World. Management with a variety of strategies is the option now remaining. WCR management in Southern Switzerland by a unique containment approach has been practiced successfully since 2003 using biotechnical means. Without any chemical pesticides or GMO input, the Swiss government mandated adherence to strict crop rotation. In addition to the economic benefits of this relatively simple approach, the environment was saved a considerable burden of pesticide applications. Other countries are invited to follow this example of sustainable pest management.

  16. Nonspreading Wave Packets for Rydberg Electrons in Rotating Molecules with Electric Dipole Moments

    International Nuclear Information System (INIS)

    Bialynicki-Birula, I.; Bialynicka-Birula, Z.

    1996-01-01

    Nonspreading wave packets for Rydberg electrons are predicted in rotating molecules with electric dipole moments. We have named them the Trojan wave packets since their stability is due to the same mechanism that governs the motion of the Trojan asteroids in the Sun-Jupiter system. Unlike all previously predicted Trojan wave packets in atoms, molecular Trojan states do not require external fields for their existence

  17. Rotating speed effect on electronic transport behaviors of Ni–Nb–Zr–H glassy alloys

    International Nuclear Information System (INIS)

    Fukuhara, Mikio

    2012-01-01

    Highlights: ► The electronic transport behaviors of (Ni 0.39 Nb 0.25 Zr 0.35 ) 100−y H y (0 ≤ y ≤ 15) glassy alloys, which produced by rotating (or quenching) speeds of 3000 and 10,000 rpm, have been studied as a function of hydrogen content. ► The resistivity for (Ni 0.39 Nb 0.25 Zr 0.35 ) 97.8 H 2.2 alloy, produced by rotating speed of 10,000 rpm, displayed 0.1 nΩ cm, which is 0.01% of silver (1.62 μΩ cm) at room temperature, between 40 and 252 K. ► Supercooling of the molten alloy induces a superior ballistic conductor and a room-temperature Coulomb oscillation. - Abstract: The electronic transport behaviors of (Ni 0.39 Nb 0.25 Zr 0.35 ) 100−y H y (0 ≤ y ≤ 15) glassy alloys, produced by rotating (or quenching) speeds of 3000 and 10,000 rpm, have been studied as a function of hydrogen content. These alloys show semiconducting, superior ballistic transport, superconducting and electric current-induced Coulomb oscillation, as hydrogen content increases. The resistivity for (Ni 0.39 Nb 0.25 Zr 0.35 ) 97.8 H 2.2 alloy, produced by rotating speed of 10,000 rpm, displayed 0.1 nΩ cm, which is 0.01% of silver (1.62 μΩ cm) at room temperature, between 40 and 252 K. The Coulomb oscillation of the 10,000 rpm-(Ni 0.39 Nb 0.25 Zr 0.35 ) 95.2 H 4.8 alloy is about 4-fold larger than that of the 3000 rpm-(Ni 0.39 Nb 0.25 Zr 0.35 ) 91.1 H 8.9 alloy. Supercooling of the molten alloy induces a superior ballistic conductor and a room-temperature Coulomb oscillation at lower and higher hydrogen contents, respectively.

  18. Integrated crop management of SRC plantations to maximise crop value, wildlife benefits and other added value opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Sage, R; Tucker, K

    1998-07-01

    This report summaries the results of a study aiming to develop an integrated approach to pest management (IPM) for the short rotation cultivation (SRC) of willows and poplars. Details are given of crop and site characteristics, non-destructive assessment of SRC biomass, the quantification of crop shadiness, and the effects of wind exposure on crop growth. The section on invertebrates covers invertebrates colonising UK SRC plantations, invertebrates which are or can become pests, natural control agents of SRC pests, the abundance and distribution of chrysomelids between sites, preferences exhibited by chrysomelids for different varieties, overwintering and dispersal of chrysomelids into SRC, and IPM of insects. The section on vertebrate fauna addresses birds in winter, the breeding birds of SRC, gamebird use of SRC, and mammals and other vertebrates of SRC. A section on ground flora deals with changes in ground flora with time, ground flora introductions, the effects of weeds on the growth of SRC, and an overview of integrated crop management in SRC plantations.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-08-15

    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

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

    Directory of Open Access Journals (Sweden)

    William Deen

    2013-02-01

    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.

  1. A rotationally symmetric electron beam chopper for picosecond pulses

    International Nuclear Information System (INIS)

    Oldfield, L.C.

    1976-01-01

    The chopper was designed for dynamic electron optical experiments where it is necessary to provide pulses of high quality with respect to both width and energy spread. The chopping action relies on the optical properties of a microwave cavity; these are exploited such that the time dependent space focusing causes a small circular aperture on the axis of rotational symmetry to transmit strongly for a single band of phase angles in each cycle of the excitation. Unless the pulses are to be used near the aperture plane, an 'energy correcting' cavity that operates in phase synchronism with the chopper is added to the system. The theoretical treatment is oriented towards computer display, and is novel in that it follows the progress of individual electron packets throughout the system. In contrast to conventional chopping and bunching theory, it is possible to analyse with ease the pulsing properties of a multicavity device. For a typical two-cavity design the pulse quality may range from 10 0 width and negligible energy spread, to 0.25% energy spread and negligible pulse width, depending on the second cavity excitation; in either situation 7.5% of the original steady beam is transmitted. (author)

  2. Research on a new type of precision cropping method with variable frequency vibration

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Aiming at the cropping operations widely applied in practical industry production, a new method of bar cropping is presented. The rotational speeds of actuating motor of eccentric blocks are controlled by a frequency-changer, and the shearing die provides the bar with the controllable force, frequency and amplitude of vibration. By utilizing the stress concentration at the bottom of V shape groove on the bar, the low stress bar cropping is realized. The bar cropping experiments of duralumin alloy and steel ...

  3. Influence of continuous cropping on corn and soybean pathogens

    OpenAIRE

    Ranzi, Camila; Camera, Juliane Nicolodi; Deuner, Carolina Cardoso

    2017-01-01

    ABSTRACT The objective of this study was to evaluate the influence of two tillage programs (conventional and no-tillage) and different rotations with soybeans and corn on the occurrence of Fusarium species. The work was conducted in the experimental field and Seed Laboratory at Iowa State University. The treatments were: tillage (no-tillage and conventional tillage), crop (corn and soybeans) and three different cropping sequences for corn and soybeans, respectively. Treatment with corn: (1) t...

  4. Nitrogen fertilizer fate after introducing maize into a continuous paddy rice cropping system

    Science.gov (United States)

    Thiemann, Irabella; He, Yao; Siemens, Jan; Brüggemann, Nicolas; Lehndorf, Eva; Amelung, Wulf

    2017-04-01

    After introducing upland crops into permanent flooded cropping systems, soil conditions temporally change from anaerobic to aerobic, which profoundly impacts nitrogen (N) dynamics. In the framework of the DFG research unit 1701 ICON we applied a single 15N-urea pulse in a field experiment in the Philippines with three different crop rotations: continuous paddy rice, paddy rice-dry rice, and paddy rice-maize. Subsequently, we traced the fate of the labelled urea in bulk soil, rhizosphere, roots, biomass and microbial residues (amino sugars) within the following two years. 15N recovery in the first 5 cm of bulk soil was highest in the first dry season of continuous paddy rice cropping (37.8 % of applied 15N) and lowest in the paddy rice-maize rotation (19.2 %). While an accumulation over time could be observed in bulk soil in 5-20 cm depth of the continuous paddy rice system, the recoveries decreased over time within the following two years in the other cropping systems. Highest 15N-recovery in shoots and roots were found in the continuous paddy rice system in the first dry season (27.3 % in shoots, 3.2 % in roots) as well as in the following wet season (4.2 % in shoots, 0.3 % in roots). Lowest recoveries in biomass were found for the paddy rice-dry rice rotation. Long-term fixation of 15N in microbial biomass residues was observed in all cropping systems (2-3 % in the 3rd dry season). The results indicate that the introduction of maize into a continuous paddy rice cropping system can reduce the fertilizer N use efficiency especially in the first year, most likely due to nitrate leaching and gaseous losses to the atmosphere.

  5. Population dynamics of plant nematodes in cultivated soil: length of rotation in newly cleared and old agricultural land.

    Science.gov (United States)

    Good, J M; Murphy, W S; Brodie, B B

    1973-04-01

    During a 6-year study of 1-, 2-, and 3-year crop rotations, population densities of Pratylenchus brachyurus, Trichodorus christiei, and Meloidogyne incognita were significantly affected by the choice of crops but not by length of crop rotation. The density of P. brachyurus and T. christiei increased rapidly on milo (Sorghum vulgate). In addition, populations of P. brachyurus increased significantly in cropping systems that involved crotalaria (C. rnucronata), millet (Setaria italica), and sudangrass (Sorghum sudanense). Lowest numbers of P. brachyurus occurred where okra (Hibiscus esculentus) was grown or where land was fallow. The largest increase in populations of T. christiei occurred in cropping systems that involved millet, sudangrass, and okra whereas the smallest increase occurred in cropping systems that involved crotalaria or fallow. A winter cover of rye (Secale cereale) had no distinguishable effect on population densities of P. brachyurus or T. christiei. Meloidogyne incognita was detected during the fourth year in both newly cleared and old agricultural land when okra was included in the cropping system. Detectable populations of M. incognita did not develop in any of the other cropping systems. Yields of tomato transplants were higher on the newly cleared land than on the old land. Highest yields were obtained when crotalaria was included in the cropping system. Lowest yields were obtained when milo, or fallow were included in the cropping system. Length of rotation had no distinguishable effect on yields of tomato transplants.

  6. {100} or 45.degree.-rotated {100}, semiconductor-based, large-area, flexible, electronic devices

    Science.gov (United States)

    Goyal, Amit [Knoxville, TN

    2012-05-15

    Novel articles and methods to fabricate the same resulting in flexible, {100} or 45.degree.-rotated {100} oriented, semiconductor-based, electronic devices are disclosed. Potential applications of resulting articles are in areas of photovoltaic devices, flat-panel displays, thermophotovoltaic devices, ferroelectric devices, light emitting diode devices, computer hard disc drive devices, magnetoresistance based devices, photoluminescence based devices, non-volatile memory devices, dielectric devices, thermoelectric devices and quantum dot laser devices.

  7. Assessing the sustainability of wheat-based cropping systems using APSIM: Model parameterisation and evaluation

    NARCIS (Netherlands)

    Moeller, C.; Pala, M.; Manschadi, A.M.; Meinke, H.B.; Sauerborn, J.

    2007-01-01

    Assessing the sustainability of crop and soil management practices in wheat-based rotations requires a well-tested model with the demonstrated ability to sensibly predict crop productivity and changes in the soil resource. The Agricultural Production Systems Simulator (APSIM) suite of models was

  8. Some environmental impacts of short rotation willow coppice

    International Nuclear Information System (INIS)

    Slater, F.M.; Hodson, R.W.; Randrson, P.F.; Lynn, S.F.

    1997-01-01

    Short rotation willow coppice is a relatively new crop in upland Britain, and particularly in Environmentally Sensitive Areas the conservation and environmental effect of biomass crops needs to be evaluated. Investigations of sewage-sludge-treated plots in mid-Wales show that, because weed control was inadequate, recovery of the flora to its semi-natural precultivated state was rapid within and between experimental plots. Soil invertebrates responded to temporal stimuli before all else. Foliar-feeding invertebrates were greater in plots which had added fertilizer. Following cultivation voles were generally lost from the ploughed areas but field mice remained. Birds were studied in more extensive areas of short rotation coppice in central England and the assemblage of species was found to be similar to those found in conventional coppice but with a foreshortened successional sequence. The conservation value of short rotation willow coppice lies mainly in the abundant foliar invertebrates that provide a rich source of food for small passerine birds, particularly summer migrants. It also provides good cover for game birds - and their predators. (author)

  9. Climatic and management drivers of CO2 exchanges by a production crop: analysis over three successive 4-year cycles.

    Science.gov (United States)

    Buysse, Pauline; Moureaux, Christine; Bodson, Bernard; Aubinet, Marc

    2016-04-01

    Carbon dioxide (CO2) exchanges between crops and the atmosphere are influenced by both climatic and crop management drivers. The investigated crop, situated at the Lonzée Terrestrial Observatory (candidate ICOS site) in the Hesbaye region in Belgium and managed for more than 70 years using conventional farming practices, was monitored over three complete sugar beet/winter wheat/potato/winter wheat rotation cycles from 2004 to 2016. Eddy covariance, automatic and manual soil chambers, leaf diffusion and biomass measurements were performed continuously in order to obtain the daily and seasonal Net Ecosystem Exchange (NEE), Gross Primary Productivity (GPP), total Ecosystem Respiration (TER), Net Primary Productivity (NPP), autotrophic respiration, heterotrophic respiration and Net Biome Production (NBP). Meteorological data and crop management practices were also recorded. Climatic and seasonal evolutions of the carbon balance components were studied and crop carbon budgets were computed both at the yearly and crop rotation cycle scales. On average over the 12 years, NEE was negative but NBP was positive, i.e. as far as carbon exportation by harvest are included in the budget, the site behaved as a carbon source. Impacts of both meteorological drivers and crop management operations on CO2 exchanges were analyzed and compared between crop types, years, and rotation cycles. The uncertainties associated to the carbon fluxes were also evaluated and discussed.

  10. Long-term effects of potato cropping system strategies on soilborne diseases and soil microbial communities

    Science.gov (United States)

    Cropping systems incorporating soil health management practices, such as longer rotations, disease-suppressive crops, reduced tillage, and/or organic amendments can substantially affect soil microbial communities, and potentially reduce soilborne potato diseases and increase productivity, but long-t...

  11. Identifiability analysis of rotational diffusion tensor and electronic transition moments measured in time-resolved fluorescence depolarization experiment

    International Nuclear Information System (INIS)

    Szubiakowski, Jacek P.

    2014-01-01

    The subject of this paper is studies of the deterministic identifiability of molecular parameters, such as rotational diffusion tensor components and orientation of electronic transition moments, resulting from the time-resolved fluorescence anisotropy experiment. In the most general case considered, a pair of perpendicularly polarized emissions enables the unique determination of all the rotational diffusion tensor's principal components. The influence of the tensor's symmetry and the associated degeneration of its eigenvalues on the identifiability of the electronic transitions moments is systematically investigated. The analysis reveals that independently of the rotational diffusion tensor's symmetry, the transition moments involved in photoselection and emission processes cannot be uniquely identified without a priori information about their mutual orientation or their orientation with respect to the principal axes of the tensor. Moreover, it is shown that increasing the symmetry of the rotational diffusion tensor deteriorates the degree of the transition moments identifiability. To obtain these results analytically, a novel approach to solve bilinear system of equations for Markov parameters is applied. The effect of the additional information, obtained from fluorescence measurements for different molecular mobilities, to improve the identifiability at various levels of analysis is shown. The effectiveness and reliability of the target analysis method for experimental determination of the molecular parameters is also discussed

  12. Impact of Organic Amendments on Global Warming Potential of Diversified Tropical Rice Rotation Systems

    Science.gov (United States)

    Janz, B.; Weller, S.; Kraus, D.; Wassmann, R.; Butterbach-Bahl, K.; Ralf, K.

    2017-12-01

    Paddy rice cultivation is increasingly challenged by irrigation water scarcity, which is forcing farmers to change traditional rice cultivation from flooded double-rice systems to the introduction of well-aerated upland crops during dry season. Emissions of methane (CH4) are expected to decrease, while there is a risk of increasing emissions of nitrous oxide (N2O) and decreasing soil organic carbon (SOC) stocks through volatilization in the form of carbon dioxide (CO2). We present a unique dataset of long-term continuous greenhouse gas emission measurements (CH4 and N2O) in the Philippines to assess global warming potentials (GWP) of diversified rice crop rotations including different field management practices such as straw residue application and legume intercropping. Since 2012, more than four years of CH4 and N2O emissions in double-rice cropping (R-R) and paddy rice rotations diversified with either maize (R-M) or aerobic rice (R-A) during dry season have been collected. Introduction of upland crops reduced irrigation water use and CH4 emissions by 66-81% and 95-99%, respectively. Although dry season N2O emissions increased twice- to threefold in the diversified systems, the strong reduction of CH4 led to a significantly lower annual GWP (CH4 + N2O) as compared to the traditional R-R system. Diversified crop management practices were first implemented during land-preparation for dry season 2015 where i) 6 t/ha rice straw was returned to the field and ii) mungbean was grown as a cover-crop between dry and wet season in addition to rice straw application. The input of organic material (straw and mungbean) led to higher substrate availability for methanogens during the following season. Therefore, GWP was 9-39% higher following straw incorporation than the control treatment. This increase was mainly driven by additional CH4 emissions. Even more, mungbean intercropping further increased GWPs, whereby the increment was highest in R-R rotation (88%) and lowest in R

  13. Microbial community responses to soil tillage and crop rotation in a corn/soybean agroecosystem.

    Science.gov (United States)

    Smith, Chris R; Blair, Peter L; Boyd, Charlie; Cody, Brianne; Hazel, Alexander; Hedrick, Ashley; Kathuria, Hitesh; Khurana, Parul; Kramer, Brent; Muterspaw, Kristin; Peck, Charles; Sells, Emily; Skinner, Jessica; Tegeler, Cara; Wolfe, Zoe

    2016-11-01

    The acreage planted in corn and soybean crops is vast, and these crops contribute substantially to the world economy. The agricultural practices employed for farming these crops have major effects on ecosystem health at a worldwide scale. The microbial communities living in agricultural soils significantly contribute to nutrient uptake and cycling and can have both positive and negative impacts on the crops growing with them. In this study, we examined the impact of the crop planted and soil tillage on nutrient levels, microbial communities, and the biochemical pathways present in the soil. We found that farming practice, that is conventional tillage versus no-till, had a much greater impact on nearly everything measured compared to the crop planted. No-till fields tended to have higher nutrient levels and distinct microbial communities. Moreover, no-till fields had more DNA sequences associated with key nitrogen cycle processes, suggesting that the microbial communities were more active in cycling nitrogen. Our results indicate that tilling of agricultural soil may magnify the degree of nutrient waste and runoff by altering nutrient cycles through changes to microbial communities. Currently, a minority of acreage is maintained without tillage despite clear benefits to soil nutrient levels, and a decrease in nutrient runoff-both of which have ecosystem-level effects and both direct and indirect effects on humans and other organisms.

  14. Soil Water Improvements with the Long Term Use of a Winter Rye Cover Crop

    Science.gov (United States)

    Basche, A.; Kaspar, T.; Archontoulis, S.; Jaynes, D. B.; Sauer, T. J.; Parkin, T.; Miguez, F.

    2015-12-01

    The Midwestern United States, a region that produces one-third of maize and one-quarter of soybeans globally, is projected to experience increasing rainfall variability with future climate change. One approach to mitigate climate impacts is to utilize crop and soil management practices that enhance soil water storage, reducing the risks of flooding and runoff as well as drought-induced crop water stress. While some research indicates that a winter cover crop in a maize-soybean rotation increases soil water, producers continue to be concerned that water use by cover crops will reduce water for a following cash crop. We analyzed continuous in-field soil moisture measurements over from 2008-2014 at a Central Iowa research site that has included a winter rye cover crop in a maize-soybean rotation for thirteen years. This period of study included years in the top third of wettest years on record (2008, 2010, 2014) as well as years in the bottom third of driest years (2012, 2013). We found the cover crop treatment to have significantly higher soil water storage from 2012-2014 when compared to the no cover crop treatment and in most years greater soil water content later in the growing season when a cover crop was present. We further found that the winter rye cover crop significantly increased the field capacity water content and plant available water compared to the no cover crop treatment. Finally, in 2012 and 2013, we measured maize and soybean biomass every 2-3 weeks and did not see treatment differences in crop growth, leaf area or nitrogen uptake. Final crop yields were not statistically different between the cover and no cover crop treatment in any of the years of this analysis. This research indicates that the long-term use of a winter rye cover crop can improve soil water dynamics without sacrificing cash crop growth.

  15. Magnetic pseudo-fields in a rotating electron-nuclear spin system

    Science.gov (United States)

    Wood, A. A.; Lilette, E.; Fein, Y. Y.; Perunicic, V. S.; Hollenberg, L. C. L.; Scholten, R. E.; Martin, A. M.

    2017-11-01

    Analogous to the precession of a Foucault pendulum observed on the rotating Earth, a precessing spin observed in a rotating frame of reference appears frequency-shifted. This can be understood as arising from a magnetic pseudo-field in the rotating frame that nevertheless has physically significant consequences, such as the Barnett effect. To detect these pseudo-fields, a rotating-frame sensor is required. Here we use quantum sensors, nitrogen-vacancy (NV) centres, in a rapidly rotating diamond to detect pseudo-fields in the rotating frame. Whereas conventional magnetic fields induce precession at a rate proportional to the gyromagnetic ratio, rotation shifts the precession of all spins equally, and thus primarily affect 13C nuclear spins in the sample. We are thus able to explore these effects via quantum sensing in a rapidly rotating frame, and define a new approach to quantum control using rotationally induced nuclear spin-selective magnetic fields. This work provides an integral step towards realizing precision rotation sensing and quantum spin gyroscopes.

  16. Spider fauna of semiarid eastern Colorado agroecosystems: diversity, abundance, and effects of crop intensification.

    Science.gov (United States)

    Kerzicnik, Lauren M; Peairs, Frank B; Cushing, Paula E; Draney, Michael L; Merrill, Scott C

    2013-02-01

    Spiders are critical predators in agroecosystems. Crop management practices can influence predator density and diversity, which, in turn, can influence pest management strategies. Crop intensification is a sustainable agricultural technique that can enhance crop production although optimizing soil moisture. To date, there is no information on how crop intensification affects natural enemy populations, particularly spiders. This study had two objectives: to characterize the abundance and diversity of spiders in eastern Colorado agroecosystems, and to test the hypothesis that spider diversity and density would be higher in wheat (Triticum aestivum L.) in crop-intensified rotations compared with wheat in conventional rotations. We collected spiders through pitfall, vacuum, and lookdown sampling from 2002 to 2007 to test these objectives. Over 11,000 spiders in 19 families from 119 species were captured from all sampling techniques. Interestingly, the hunting spider guild represented 89% of the spider fauna captured from all sites with the families Gnaphosidae and Lycosidae representing 75% of these spiders. Compared with European agroecosystems, these agroecosystems had greater diversity, which can be beneficial for the biological control of pests. Overall, spider densities were low in these semiarid cropping systems, and crop intensification effects on spider densities were not evident at this scale.

  17. The Importance of Rotational Crops for Biodiversity Conservation in Mediterranean Areas.

    Science.gov (United States)

    Chiatante, Gianpasquale; Meriggi, Alberto

    2016-01-01

    Nowadays we are seeing the largest biodiversity loss since the extinction of the dinosaurs. To conserve biodiversity it is essential to plan protected areas using a prioritization approach, which takes into account the current biodiversity value of the sites. Considering that in the Mediterranean Basin the agro-ecosystems are one of the most important parts of the landscape, the conservation of crops is essential to biodiversity conservation. In the framework of agro-ecosystem conservation, farmland birds play an important role because of their representativeness, and because of their steady decline in the last Century in Western Europe. The main aim of this research was to define if crop dominated landscapes could be useful for biodiversity conservation in a Mediterranean area in which the landscape was modified by humans in the last thousand years and was affected by the important biogeographical phenomenon of peninsula effect. To assess this, we identify the hotspots and the coldspots of bird diversity in southern Italy both during the winter and in the breeding season. In particular we used a scoring method, defining a biodiversity value for each cell of a 1-km grid superimposed on the study area, using data collected by fieldwork following a stratified random sampling design. This value was analysed by a multiple linear regression analysis and was predicted in the whole study area. Then we defined the hotspots and the coldspots of the study area as 15% of the cells with higher and lower value of biodiversity, respectively. Finally, we used GAP analysis to compare hotspot distribution with the current network of protected areas. This study showed that the winter hotspots of bird diversity were associated with marshes and water bodies, shrublands, and irrigated crops, whilst the breeding hotspots were associated with more natural areas (e.g. transitional wood/shrubs), such as open areas (natural grasslands, pastures and not irrigated crops). Moreover, the

  18. The Importance of Rotational Crops for Biodiversity Conservation in Mediterranean Areas.

    Directory of Open Access Journals (Sweden)

    Gianpasquale Chiatante

    Full Text Available Nowadays we are seeing the largest biodiversity loss since the extinction of the dinosaurs. To conserve biodiversity it is essential to plan protected areas using a prioritization approach, which takes into account the current biodiversity value of the sites. Considering that in the Mediterranean Basin the agro-ecosystems are one of the most important parts of the landscape, the conservation of crops is essential to biodiversity conservation. In the framework of agro-ecosystem conservation, farmland birds play an important role because of their representativeness, and because of their steady decline in the last Century in Western Europe. The main aim of this research was to define if crop dominated landscapes could be useful for biodiversity conservation in a Mediterranean area in which the landscape was modified by humans in the last thousand years and was affected by the important biogeographical phenomenon of peninsula effect. To assess this, we identify the hotspots and the coldspots of bird diversity in southern Italy both during the winter and in the breeding season. In particular we used a scoring method, defining a biodiversity value for each cell of a 1-km grid superimposed on the study area, using data collected by fieldwork following a stratified random sampling design. This value was analysed by a multiple linear regression analysis and was predicted in the whole study area. Then we defined the hotspots and the coldspots of the study area as 15% of the cells with higher and lower value of biodiversity, respectively. Finally, we used GAP analysis to compare hotspot distribution with the current network of protected areas. This study showed that the winter hotspots of bird diversity were associated with marshes and water bodies, shrublands, and irrigated crops, whilst the breeding hotspots were associated with more natural areas (e.g. transitional wood/shrubs, such as open areas (natural grasslands, pastures and not irrigated crops

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

    Energy Technology Data Exchange (ETDEWEB)

    Biertuempfel, A.; Buttlar, C. von; Conrad, M. [and others

    2012-08-15

    In the brochure under consideration the Agency for Renewable Resources (Guelzow-Pruezen, Federal Republic of Germany) reports on the support of the implementation of different plant cultures in structure of plantations and crop rotation systems of companies under consideration of the Federal State Saxony. The main chapters of this brochure are: Crops for the production of biogas; implementation in plantations; ensilage and biogas yields; economy of the cultivation of energy plants.

  20. Energy crops for biogas plants. Thuringia; Energiepflanzen fuer Biogasanlagen. Thueringen

    Energy Technology Data Exchange (ETDEWEB)

    Biertuempfel, A.; Bischof, R.; Conrad, M. (and others)

    2012-06-15

    In the brochure under consideration the Agency for Renewable Resources (Guelzow-Pruezen, Federal Republic of Germany) reports on the support of the implementation of different plant cultures in structure of plantations and crop rotation systems of companies under consideration of the Federal State Thuringia. The main chapters of this brochure are: Crops for the production of biogas; implementation in plantations; ensilage and biogas yields; economy of the cultivation of energy plants.

  1. Nascent rotational distributions of N+2(X 2Σ+/sub g/) produced by electron-impact ionization of N2 in a supersonic beam

    International Nuclear Information System (INIS)

    Nagata, T.; Nakajima, A.; Kondow, T.; Kuchitsu, K.

    1987-01-01

    Laser-induced fluorescence from nascent N + 2 (X 2 Σ + /sub g/) ions produced by electron impact on a N 2 supersonic beam was observed. An analysis of the B 2 Σ + /sub u/-X 2 Σ + /sub g/ (0,0) band shows that the rotational state distributions cannot be represented by a single Boltzmann function, higher N'' levels being overpopulated. Experimental and analytical efforts were made to minimize the influence of cascading and relaxation on the rotational distributions. The rotational energy of N + 2 (X) thus estimated increases with decreasing electron energy from 2.26 +- 0.16 meV at 300 eV to 4.24 +- 0.27 meV at 25 eV. This trend is explained qualitatively in terms of angular momentum transfer through multipole electron--molecule interactions

  2. Water footprint of crop production for different crop structures in the Hebei southern plain, North China

    Science.gov (United States)

    Chu, Yingmin; Shen, Yanjun; Yuan, Zaijian

    2017-06-01

    The North China Plain (NCP) has a serious shortage of freshwater resources, and crop production consumes approximately 75 % of the region's water. To estimate water consumption of different crops and crop structures in the NCP, the Hebei southern plain (HSP) was selected as a study area, as it is a typical region of groundwater overdraft in the NCP. In this study, the water footprint (WF) of crop production, comprised of green, blue and grey water footprints, and its annual variation were analyzed. The results demonstrated the following: (1) the WF from the production of main crops was 41.8 km3 in 2012. Winter wheat, summer maize and vegetables were the top water-consuming crops in the HSP. The water footprint intensity (WFI) of cotton was the largest, and for vegetables, it was the smallest; (2) the total WF, WFblue, WFgreen and WFgrey for 13 years (2000-2012) of crop production were 604.8, 288.5, 141.3 and 175.0 km3, respectively, with an annual downtrend from 2000 to 2012; (3) winter wheat, summer maize and vegetables consumed the most groundwater, and their blue water footprint (WFblue) accounted for 74.2 % of the total WFblue in the HSP; (4) the crop structure scenarios analysis indicated that, with approximately 20 % of arable land cultivated with winter wheat-summer maize in rotation, 38.99 % spring maize, 10 % vegetables and 10 % fruiters, a sustainable utilization of groundwater resources can be promoted, and a sufficient supply of food, including vegetables and fruits, can be ensured in the HSP.

  3. Modeling Long Term Corn Yield Response to Nitrogen Rate and Crop Rotation

    Directory of Open Access Journals (Sweden)

    Laila Alejandra Puntel

    2016-11-01

    Full Text Available Improved prediction of optimal N fertilizer rates for corn (Zea mays L. can reduce N losses and increase profits. We tested the ability of the Agricultural Production Systems sIMulator (APSIM to simulate corn and soybean (Glycine max L. yields, the economic optimum N rate (EONR using a 16-year field-experiment dataset from central Iowa, USA that included two crop sequences (continuous corn and soybean-corn and five N fertilizer rates (0, 67, 134, 201, and 268 kg N ha-1 applied to corn. Our objectives were to: a quantify model prediction accuracy before and after calibration, and report calibration steps; b compare crop model-based techniques in estimating optimal N rate for corn; and c utilize the calibrated model to explain factors causing year to year variability in yield and optimal N. Results indicated that the model simultaneously simulated well long-term crop yields response to N (relative root mean square error, RRMSE of 19.6% before and 12.3% after calibration, which provided strong evidence that important soil and crop processes were accounted for in the model. The prediction of EONR was more complex and had greater uncertainty than the prediction of crop yield (RRMSE of 44.5% before and 36.6% after calibration. For long-term site mean EONR predictions, both calibrated and uncalibrated versions can be used as the 16-yr mean differences in EONR’s were within the historical N rate error range (40 to 50 kg N ha-1. However, for accurate year-by-year simulation of EONR the calibrated version should be used. Model analysis revealed that higher EONR values in years with above normal spring precipitation were caused by an exponential increase in N loss (denitrification and leaching with precipitation. We concluded that long term experimental data were valuable in testing and refining APSIM predictions. The model can be used as a tool to assist N management guidelines in the US Midwest and we identified five avenues on how the model can add

  4. Modeling Long-Term Corn Yield Response to Nitrogen Rate and Crop Rotation.

    Science.gov (United States)

    Puntel, Laila A; Sawyer, John E; Barker, Daniel W; Dietzel, Ranae; Poffenbarger, Hanna; Castellano, Michael J; Moore, Kenneth J; Thorburn, Peter; Archontoulis, Sotirios V

    2016-01-01

    Improved prediction of optimal N fertilizer rates for corn ( Zea mays L. ) can reduce N losses and increase profits. We tested the ability of the Agricultural Production Systems sIMulator (APSIM) to simulate corn and soybean ( Glycine max L. ) yields, the economic optimum N rate (EONR) using a 16-year field-experiment dataset from central Iowa, USA that included two crop sequences (continuous corn and soybean-corn) and five N fertilizer rates (0, 67, 134, 201, and 268 kg N ha -1 ) applied to corn. Our objectives were to: (a) quantify model prediction accuracy before and after calibration, and report calibration steps; (b) compare crop model-based techniques in estimating optimal N rate for corn; and (c) utilize the calibrated model to explain factors causing year to year variability in yield and optimal N. Results indicated that the model simulated well long-term crop yields response to N (relative root mean square error, RRMSE of 19.6% before and 12.3% after calibration), which provided strong evidence that important soil and crop processes were accounted for in the model. The prediction of EONR was more complex and had greater uncertainty than the prediction of crop yield (RRMSE of 44.5% before and 36.6% after calibration). For long-term site mean EONR predictions, both calibrated and uncalibrated versions can be used as the 16-year mean differences in EONR's were within the historical N rate error range (40-50 kg N ha -1 ). However, for accurate year-by-year simulation of EONR the calibrated version should be used. Model analysis revealed that higher EONR values in years with above normal spring precipitation were caused by an exponential increase in N loss (denitrification and leaching) with precipitation. We concluded that long-term experimental data were valuable in testing and refining APSIM predictions. The model can be used as a tool to assist N management guidelines in the US Midwest and we identified five avenues on how the model can add value toward

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

    DEFF Research Database (Denmark)

    Chirinda, N.; Carter, Mette Sustmann; Albert, Kristian Rost

    2010-01-01

    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...

  6. Energy crops. Data for planning of energy crop cultivation. KTBL data compilation with internet services; Energiepflanzen. Daten fuer die Planung des Energiepflanzenanbaus. KTBL-Datensammlung mit Internetangebot

    Energy Technology Data Exchange (ETDEWEB)

    Eckel, H.; Grube, J.; Zimmer, E. (comps.)

    2006-07-01

    Based on the KTBL data compilation ''Betriebsplanung Landwirtschaft'', this data compilation (''Datensammlung Energiepflanzen'') provides comprehensive information on the cultivation of energy crops and production planning. Production techniques are outlined up to the final step of provision to the consumer, so that full-scale cost calculation is possible. Hints for cultivation are presented which take into account the differences between food and fodder crop cultivation. Rare crops are gone into for which little experience is available but which have great potential for utilisation in agriculture. Energetic utilisation is a field for a wider range of crops and with new options for crop rotation. These are discussed in two separate chapters. There is also information on legal aspects of energy crop production, relevant standards, and quality requirements on substrates for energetic use and for secondary harvesting. (orig.)

  7. [Effects of intercropping Sedum plumbizincicola in wheat growth season under wheat-rice rotation on the crops growth and their heavy metals uptake from different soil types].

    Science.gov (United States)

    Zhao, Bing; Shen, Li-bo; Cheng, Miao-miao; Wang, Song-feng; Wu, Long-hua; Zhou, Shou-biao; Luo, Yong-ming

    2011-10-01

    A pot experiment with heavy metals- contaminated black soil from Heilongjiang Province, alluvial soil from Henan Province, and paddy soil from Zhejiang Province was conducted to study the effects of intercropping Sedum plumbizincicola in wheat growth season under wheat (Triticum aestivum) - rice (Oryza sativa) rotation on the growth of the crops and their heavy metals uptake, aimed to explore the feasibility of simultaneous grain production and heavy metals-contaminated soil phytoremediation in main food crop production areas of this country. Comparing with monoculture T. aestivum, intercropping S. plumbizincicola increased the soil NaNO3 -extractable Zn and Cd significantly, with the increment of extractable Zn in test paddy soil, alluvial soil, and black soil being 55%, 32% and 110%, and that of extractable Cd in test paddy soil and black soil being 38% and 110%, respectively. The heavy metals concentration in T. aestivum shoots under intercropping S. plumbizincicola was 0.1-0.9 times higher than that under monoculture T. aestivum, but the intercropping had little effects on the rice growth and its heavy metals uptake. Though the Cd concentration in rice grain after S. plumbizincicola planting was still higher than 0.2 mg kg(-1) (the limit of Cd in food standard), it presented a decreasing trend, as compared with that after monoculture T. aestivum. Therefore, intercropping S. plumbizincicola in wheat growth season under wheat-rice rota- tion could benefit the phytoremediation of heavy metals-contaminated soil, and decrease the food-chain risk of rotated rice.

  8. Converging strategies by farmers and scientists to improve soil fertility and enhance crop production in Benin

    NARCIS (Netherlands)

    Saidou, A.

    2006-01-01

    Keywords: Farmer perception, indigenous knowledge, extensive cassava, earthworm casts, arbuscular mycorrhiza, crop rotation, nutrient uptake, soil fertility, co-research, land tenure.Farmers in the transitional zone of Benin claim that extensive cassava cropping and prior cotton fertiliser enhance

  9. Reducing soil erosion and nutrient loss on sloping land under crop-mulberry management system.

    Science.gov (United States)

    Fan, Fangling; Xie, Deti; Wei, Chaofu; Ni, Jiupai; Yang, John; Tang, Zhenya; Zhou, Chuan

    2015-09-01

    Sloping croplands could result in soil erosion, which leads to non-point source pollution of the aquatic system in the Three Gorges Reservoir Region. Mulberry, a commonly grown cash plant in the region, is traditionally planted in contour hedgerows as an effective management practice to control soil erosion and non-point source pollution. In this field study, surface runoff and soil N and P loss on sloping land under crop-mulberry management were investigated. The experiments consisted of six crop-mulberry treatments: Control (no mulberry hedgerow with mustard-corn rotation); T1 (two-row contour mulberry with mustard-corn rotation); T2 (three-row contour mulberry with mustard-corn rotation); T3 (border mulberry and one-row contour mulberry with mustard-corn rotation); T4 (border mulberry with mustard-corn rotation); T5 (two-row longitudinal mulberry with mustard). The results indicated that crop-mulberry systems could effectively reduce surface runoff and soil and nutrient loss from arable slope land. Surface runoff from T1 (342.13 m(3) hm(-2)), T2 (260.6 m(3) hm(-2)), T3 (113.13 m(3) hm(-2)), T4 (114 m(3) hm(-2)), and T5 (129 m(3) hm(-2)) was reduced by 15.4, 35.6, 72.0, 71.8, and 68.1%, respectively, while soil loss from T1 (0.21 t hm(-2)), T2 (0.13 t hm(-2)), T3 (0.08 t hm(-2)), T4 (0.11 t hm(-2)), and T5 (0.12 t hm(-2)) was reduced by 52.3, 70.5, 81.8, 75.0, and 72.7%, respectively, as compared with the control. Crop-mulberry ecosystem would also elevate soil N by 22.3% and soil P by 57.4%, and soil nutrient status was contour-line dependent.

  10. Water erosion during a 17-year period under two crop rotations in four soil management systems on a Southbrazilian Inceptisol

    Science.gov (United States)

    Bertol, Ildegardis; Vidal Vázquez, Eva; Paz Ferreiro, Jorge

    2010-05-01

    Soil erosion still remains a persistent issue in the world, and this in spite of the efforts to ameliorate soil management systems taken into account the point of view of environmental protection against soil losses. In South Brazil water erosion is mainly associated to rainfall events with a great volume and high intensity, which are more or less evenly distributed all over the year. Nowadays, direct drilling is the most widely soil management system used for the main crops of the region. However, some crops still are grown on conventionally tilled soils, which means mainly ploughing and harrowing and less frequently chisel ploughing. In Lages-Santa Catarina State, Brazil, a plot experiment under natural rain was started in 1992 on an Inceptisol with the aim of quantifying soil and water losses. Treatments included bare and vegetated plots. The crop succession was: oats (Avena strigosa), soybean (Glycine max), vetch (Vicia sativa), maize (Zea mays), fodder radish (Raphanus sativus) and beans (Phaseolus vulgaris). Soil tillage systems investigated in this study were: i) conventional tillage (CT), ii) reduced tillage (MT), iii) no tillage (NT) under crop rotation and iv) conventional tillage on bare soil (BS). Treatments CT and BS involved ploughing plus twice harrowing, whereas MT involved chisel ploughing plus harrowing. Rainfall erosivity from January 1 1992 to December 31 2009 was calculated. Soil losses from the BS treatment along the 17 year study period were higher than 1200 Mg ha-1. Crop cover significantly reduced erosion, so that under some crops soil losses in the CT treatment were 80% lower than in the BS treatment. In turn soil losses in the MT treatment, where tillage was performed by chiselling and harrowing, were on average about 50% lower than in the CT treatment. No tillage was the most efficient soil management system in reducing soil erosion, so that soil losses in the NT treatment were about 98% lower than in the BS treatment. The three

  11. Quantum mechanics of electronic-rotational energy transfer in F(2P) + H2 collisions

    International Nuclear Information System (INIS)

    Wyatt, R.E.; Walker, R.B.

    1977-01-01

    A theoretical study is made of electronic-rotational energy transfer in F( 2 P) + H 2 three-dimensional collisions, with electronic matrix elements from DIM theory. The quantum close-coupled equations are integrated via the R-matrix propagation method. Inelastic quenching probabilities are emphasized, with and without simulated open reaction channels. Interweaving patterns in the transition probability for even and odd nuclear parity vs. J (total angular momentum quantum number) are analyzed in terms of avoided crossing structure in the electrotational energy correlation diagrams. Localized regions where electronic quenching is dominant are identified in the correlation diagrams, and are confirmed in separate calculations which neglect interchannel mixing in local regions of the atom-molecule separation. Open reaction channels are found to have little influence on the quenching probabilities in these low energy calculations

  12. Assessing the Influence of Summer Organic Fertilization Combined with Nitrogen Inhibitor on a Short Rotation Woody Crop in Mediterranean Environment

    Directory of Open Access Journals (Sweden)

    Anita Maienza

    2014-01-01

    Full Text Available The European Union Directive 91/676/EEC, known as Nitrates Directive, has dictated basic agronomic principles regarding the use of animal manure source as well as livestock and waste waters from small food companies. The use of nitrification inhibitors together with animal effluents as organic fertilizers could be beneficial for nutrient recycling, plant productivity, and greenhouse gas emission and could offer economic advantages as alternative to conventional fertilizers especially in the Mediterranean region. The aim of the present study was to investigate differences in plant productivity between bovine effluent treatments with (or without addition of a nitrification inhibitor (3,4 DMPP in a short rotation woody crop system. Results of the field experiment carried out in a Mediterranean dry environment indicated that the proposed strategy could improve tree growth with indirect, beneficial effects for agroforestry systems.

  13. Relationship between weed dormancy and herbicide rotations: implications in resistance evolution.

    Science.gov (United States)

    Darmency, Henri; Colbach, Nathalie; Le Corre, Valérie

    2017-10-01

    It is suggested that selection for late germinating seed cohorts is significantly associated with herbicide resistance in some cropping systems. In turn, it is conceivable that rotating herbicide modes of action selects for populations with mutations for increased secondary dormancy, thus partially overcoming the delaying effect of rotation on resistance evolution. Modified seed dormancy could affect management strategies - like herbicide rotation - that are used to prevent or control herbicide resistance. Here, we review the literature for data on seed dormancy and germination dynamics of herbicide-resistant versus susceptible plants. Few studies use plant material with similar genetic backgrounds, so there are few really comparative data. Increased dormancy and delayed germination may co-occur with resistance to ACCase inhibitors, but there is no clear-cut link with resistance to other herbicide classes. Population shifts are due in part to pleiotropic effects of the resistance genes, but interaction with the cropping system is also possible. We provide an example of a model simulation that accounts for genetic diversity in the dormancy trait, and subsequent consequences for various cropping systems. We strongly recommend adding more accurate and detailed mechanistic modelling to the current tools used today to predict the efficiency of prevention and management of herbicide resistance. These models should be validated through long-term experimental designs including mono-herbicide versus chemical rotation in the field. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Cover Crop Species and Management Influence Predatory Arthropods and Predation in an Organically Managed, Reduced-Tillage Cropping System.

    Science.gov (United States)

    Rivers, Ariel N; Mullen, Christina A; Barbercheck, Mary E

    2018-04-05

    Agricultural practices affect arthropod communities and, therefore, have the potential to influence the activities of arthropods. We evaluated the effect of cover crop species and termination timing on the activity of ground-dwelling predatory arthropods in a corn-soybean-wheat rotation in transition to organic production in Pennsylvania, United States. We compared two cover crop treatments: 1) hairy vetch (Vicia villosa Roth) planted together with triticale (×Triticosecale Wittmack) after wheat harvest, and 2) cereal rye (Secale cereale Linnaeus) planted after corn harvest. We terminated the cover crops in the spring with a roller-crimper on three dates (early, middle, and late) based on cover crop phenology and standard practices for cash crop planting in our area. We characterized the ground-dwelling arthropod community using pitfall traps and assessed relative predation using sentinel assays with live greater waxworm larvae (Galleria mellonella Fabricius). The activity density of predatory arthropods was significantly higher in the hairy vetch and triticale treatments than in cereal rye treatments. Hairy vetch and triticale favored the predator groups Araneae, Opiliones, Staphylinidae, and Carabidae. Specific taxa were associated with cover crop condition (e.g., live or dead) and termination dates. Certain variables were positively or negatively associated with the relative predation on sentinel prey, depending on cover crop treatment and stage, including the presence of predatory arthropods and various habitat measurements. Our results suggest that management of a cover crop by roller-crimper at specific times in the growing season affects predator activity density and community composition. Terminating cover crops with a roller-crimper can conserve generalist predators.

  15. Malabsorption of mineral nutrients and effects of foliar fertilization on continuously cropped capsicum annuum l. var. annuum

    International Nuclear Information System (INIS)

    Ye, X.H.; Zhao, Z.L.; Zhao, Z.L.; Zhao, H.B.

    2014-01-01

    Cayenne pepper (C. annuum var. annuum) cultivar known as line No. 5 was used to establish a reference baseline for fertilization experiments under conditions of continuous cropping versus crop rotation. The effects of continuous cropping on absorption of 11 essential nutrient elements and fruit yield were studied. Concurrently, we also examined the effects of foliar application of urea + KH/sub 2/ PO/sub 4/ and Fe + B + Zn + Mn on nutrient absorption due to continuous cropping. The results showed that, compared with peppers grown in rotation soil, continuous cropping affected the uptake of eight elements (P, K, Mg, Fe, B, Zn, Mn, Cu) and transport of these elements to the aerial parts of the plant, although the element concentrations in continuous cropping soil were not lower than those in rotation soil. Continuous cropping caused a decline in fruit yield. The impact of continuous cropping on the uptake of trace elements was greater than it was for macro elements. Foliar application of urea + KH/sub 2/ PO/sub 4/ significantly improved the P, Mg, Fe, and Mo content of continuously-cropped pepper plants, but did not significantly improve the content of N and K, and there was an antagonistic effect on Zn uptake. Foliar application of Fe + B + Zn + Mn, significantly increased the Fe, B, Zn, Mn, and P content in the plants; Ca uptake in the leaves and fruits was promoted to a certain degree, but there was obvious antagonism toward Mo and Cu uptake in the stems, leaves and fruits. Pepper fruit yields were significantly increased by foliar application of urea + KH/sub 2/ PO/sub 4/ or foliar application of Fe + B + Zn + Mn. However the effects of foliar application of Fe + B + Zn + Mn on increased production were significantly better than the effects of foliar application of urea + KH/sub 2/ PO/sub 4/. (author)

  16. Land Use, Yield and Quality Changes of Minor Field Crops: Is There Superseded Potential to Be Reinvented in Northern Europe?

    Science.gov (United States)

    Peltonen-Sainio, Pirjo; Jauhiainen, Lauri; Lehtonen, Heikki

    2016-01-01

    Diversification of agriculture was one of the strengthened aims of the greening payment of European Agricultural Policy (CAP) as diversification provides numerous ecosystems services compared to cereal-intensive crop rotations. This study focuses on current minor crops in Finland that have potential for expanded production and considers changes in their cropping areas, yield trends, breeding gains, roles in crop rotations and potential for improving resilience. Long-term datasets of Natural Resources Institute Finland and farmers' land use data from the Agency of Rural Affairs were used to analyze the above-mentioned trends and changes. The role of minor crops in rotations declined when early and late CAP periods were compared and that of cereal monocultures strengthened. Genetic yield potentials of minor crops have increased as also genetic improvements in quality traits, although some typical trade-offs with improved yields have also appeared. However, the gap between potential and attained yields has expanded, depending on the minor crop, as national yield trends have either stagnated or declined. When comparing genetic improvements of minor crops to those of the emerging major crop, spring wheat, breeding achievements in minor crops were lower. It was evident that the current agricultural policies in the prevailing market and the price environment have not encouraged cultivation of minor crops but further strengthened the role of cereal monocultures. We suggest optimization of agricultural land use, which is a core element of sustainable intensification, as a future means to couple long-term environmental sustainability with better success in economic profitability and social acceptability. This calls for development of effective policy instruments to support farmer's diversification actions.

  17. Projective analysis of staple food crop productivity in adaptation to future climate change in China.

    Science.gov (United States)

    Zhang, Qing; Zhang, Wen; Li, Tingting; Sun, Wenjuan; Yu, Yongqiang; Wang, Guocheng

    2017-08-01

    Climate change continually affects our capabilities to feed the increasing population. Rising temperatures have the potential to shorten the crop growth duration and therefore reduce crop yields. In the past decades, China has successfully improved crop cultivars to stabilize, and even lengthen, the crop growth duration to make use of increasing heat resources. However, because of the complex cropping systems in the different regions of China, the possibility and the effectiveness of regulating crop growth duration to reduce the negative impacts of future climate change remain questionable. Here, we performed a projective analysis of the staple food crop productivity in double-rice, wheat-rice, wheat-maize, single-rice, and single-maize cropping systems in China using modeling approaches. The results indicated that from the present to the 2040s, the warming climate would shorten the growth duration of the current rice, wheat, and maize cultivars by 2-24, 11-13, and 9-29 days, respectively. The most significant shortening of the crop growth duration would be in Northeast China, where single-rice and single-maize cropping dominates the croplands. The shortened crop growth duration would consequently reduce crop productivity. The most significant decreases would be 27-31, 6-20, and 7-22% for the late crop in the double-rice rotation, wheat in the winter wheat-rice rotation, and single maize, respectively. However, our projection analysis also showed that the negative effects of the warming climate could be compensated for by stabilizing the growth duration of the crops via improvement in crop cultivars. In this case, the productivity of rice, wheat, and maize in the 2040s would increase by 4-16, 31-38, and 11-12%, respectively. Our modeling results implied that the possibility of securing future food production exists by adopting proper adaptation options in China.

  18. Projective analysis of staple food crop productivity in adaptation to future climate change in China

    Science.gov (United States)

    Zhang, Qing; Zhang, Wen; Li, Tingting; Sun, Wenjuan; Yu, Yongqiang; Wang, Guocheng

    2017-08-01

    Climate change continually affects our capabilities to feed the increasing population. Rising temperatures have the potential to shorten the crop growth duration and therefore reduce crop yields. In the past decades, China has successfully improved crop cultivars to stabilize, and even lengthen, the crop growth duration to make use of increasing heat resources. However, because of the complex cropping systems in the different regions of China, the possibility and the effectiveness of regulating crop growth duration to reduce the negative impacts of future climate change remain questionable. Here, we performed a projective analysis of the staple food crop productivity in double-rice, wheat-rice, wheat-maize, single-rice, and single-maize cropping systems in China using modeling approaches. The results indicated that from the present to the 2040s, the warming climate would shorten the growth duration of the current rice, wheat, and maize cultivars by 2-24, 11-13, and 9-29 days, respectively. The most significant shortening of the crop growth duration would be in Northeast China, where single-rice and single-maize cropping dominates the croplands. The shortened crop growth duration would consequently reduce crop productivity. The most significant decreases would be 27-31, 6-20, and 7-22% for the late crop in the double-rice rotation, wheat in the winter wheat-rice rotation, and single maize, respectively. However, our projection analysis also showed that the negative effects of the warming climate could be compensated for by stabilizing the growth duration of the crops via improvement in crop cultivars. In this case, the productivity of rice, wheat, and maize in the 2040s would increase by 4-16, 31-38, and 11-12%, respectively. Our modeling results implied that the possibility of securing future food production exists by adopting proper adaptation options in China.

  19. Residual soil nitrate content and profitability of five cropping systems in northwest Iowa.

    Science.gov (United States)

    De Haan, Robert L; Schuiteman, Matthew A; Vos, Ronald J

    2017-01-01

    Many communities in the Midwestern United States obtain their drinking water from shallow alluvial wells that are vulnerable to contamination by NO3-N from the surrounding agricultural landscape. The objective of this research was to assess cropping systems with the potential to produce a reasonable return for farmers while simultaneously reducing the risk of NO3-N movement into these shallow aquifers. From 2009 to 2013 we conducted a field experiment in northwest Iowa in which we evaluated five cropping systems for residual (late fall) soil NO3-N content and profitability. Soil samples were taken annually from the top 30 cm of the soil profile in June and August, and from the top 180 cm in November (late fall). The November samples were divided into 30 cm increments for analysis. Average residual NO3-N content in the top 180 cm of the soil profile following the 2010 to 2013 cropping years was 134 kg ha-1 for continuous maize (Zea mays L.) with a cereal rye (Secale cereale L.) cover crop, 18 kg ha-1 for perennial grass, 60 kg ha-1 for a three year oat (Avena sativa L.)-alfalfa (Medicago sativa L.)-maize rotation, 85 kg ha-1 for a two year oat/red clover (Trifolium pratense L.)-maize rotation, and 90 kg ha-1 for a three year soybean (Glycine max (L.) Merr.)-winter wheat (Triticum aestivum L.)-maize rotation. However, residual NO3-N in the 90 to 180 cm increment of the soil profile was not significantly higher in the oat-alfalfa-maize cropping system than the perennial grass system. For 2010 to 2013, average profit ($ ha-1 yr-1) was 531 for continuous corn, 347 for soybean-winter wheat-maize, 264 for oat-alfalfa-maize, 140 for oat/red clover-maize, and -384 (loss) for perennial grass. Considering both residual soil NO3-N and profitability data, the oat-alfalfa-maize rotation performed the best in this setting. However, given current economic pressures widespread adoption is likely to require changes in public policy.

  20. On the interplay of morphology and electronic conductivity of rotationally spun carbon fiber mats

    Science.gov (United States)

    Opitz, Martin; Go, Dennis; Lott, Philipp; Müller, Sandra; Stollenwerk, Jochen; Kuehne, Alexander J. C.; Roling, Bernhard

    2017-09-01

    Carbon-based materials are used as electrode materials in a wide range of electrochemical applications, e.g., in batteries, supercapacitors, and fuel cells. For these applications, the electronic conductivity of the materials plays an important role. Currently, porous carbon materials with complex morphologies and hierarchical pore structures are in the focus of research. The complex morphologies influence the electronic transport and may lead to an anisotropic electronic conductivity. In this paper, we unravel the influence of the morphology of rotationally spun carbon fiber mats on their electronic conductivity. By combining experiments with finite-element simulations, we compare and evaluate different electrode setups for conductivity measurements. While the "bar-type method" with two parallel electrodes on the same face of the sample yields information about the intrinsic conductivity of the carbon fibers, the "parallel-plate method" with two electrodes on opposite faces gives information about the electronic transport orthogonal to the faces. Results obtained for the van-der-Pauw method suggest that this method is not well suited for understanding morphology-transport relations in these materials.

  1. Senior Research Connects Students with a Living Laboratory As Part of an Integrated Crop and Livestock System

    Science.gov (United States)

    Senturklu, Songul; Landblom, Douglas; Brevik, Eric C.

    2015-04-01

    Soil, water, soil microbes, and solar energy are the main sources that sustain life on this planet. Without them working in concert, neither plants nor animals would survive. Considering the efficiency of animal production targets, soil must be protected and improved. Therefore, through our sustainable integrated crop and livestock research, we are studying animal and soil interactions from the soil to the plate. Integrating beef cattle systems into a diverse cropping system is providing a living laboratory for education beyond the traditional classroom setting. To establish the living learning laboratory at the Dickinson Research Extension Center, a five-crop rotation was established that included adapted cool and warm season grasses and broadleaf crops. The crop rotation is: sunflower > hard red spring wheat > fall seeded winter triticale-hairy vetch (hay)/spring seeded 7-species cover crop > Corn (85-95 day varieties) > field pea-barley intercrop. Sunflower and spring wheat are harvested for cash crop income in the rotation. Livestock integration occurs when yearling steers that had previously grazed perennial pastures until mid-August graze field pea-barley and subsequently unharvested corn. Average grazing days for field pea-barley and unharvested corn is 30 and 70 days, respectively. At the end of the grazing period, the yearling steers average 499-544 kg and are moved to a feedlot and fed an additional 75 days until slaughter. Maximizing grazing days and extending the grazing season through integration with the cropping system reduces custom feeding costs and enhances animal profit. Beef cows do not require high quality feed after their calves have been weaned. Therefore, gestating beef cows are an ideal animal to graze cover crops and crop aftermath (residue) after yearling steer grazing and farming operations have been completed. Extending the grazing season for beef cows by grazing cover crops and residues reduces winter feed cost, which is one of the

  2. Cover crops and crop residue management under no-till systems improve soils and environmental quality

    Science.gov (United States)

    Kumar, Sandeep; Wegner, Brianna; Vahyala, Ibrahim; Osborne, Shannon; Schumacher, Thomas; Lehman, Michael

    2015-04-01

    Crop residue harvest is a common practice in the Midwestern USA for the ethanol production. However, excessive removal of crop residues from the soil surface contributes to the degradation of important soil quality indicators such as soil organic carbon (SOC). Addition of a cover crop may help to mitigate these negative effects. The present study was set up to assess the impacts of corn (Zea mays L.) residue removal and cover crops on various soil quality indicators and surface greenhouse gas (GHG) fluxes. The study was being conducted on plots located at the North Central Agricultural Research Laboratory (NCARL) in Brookings, South Dakota, USA. Three plots of a corn and soybean (Glycine max (L.) Merr.) rotation under a no-till (NT) system are being monitored for soils and surface gas fluxes. Each plot has three residue removal (high residue removal, HRR; medium residue removal, MRR; and low residue removal, LRR) treatments and two cover crops (cover crops and no cover crops) treatments. Both corn and soybean are represented every year. Gas flux measurements were taken weekly using a closed static chamber method. Data show that residue removal significantly impacted soil quality indicators while more time was needed for an affect from cover crop treatments to be noticed. The LRR treatment resulted in higher SOC concentrations, increased aggregate stability, and increased microbial activity. The LRR treatment also increased soil organic matter (SOM) and particulate organic matter (POM) concentrations. Cover crops used in HRR (high corn residue removal) improved SOC (27 g kg-1) by 6% compared to that without cover crops (25.4 g kg-1). Cover crops significantly impacted POM concentration directly after the residue removal treatments were applied in 2012. CO2 fluxes were observed to increase as temperature increased, while N2O fluxes increased as soil moisture increased. CH4 fluxes were responsive to both increases in temperature and moisture. On average, soils under

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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)

  4. Steers grazing of a rye cover crop influences growth of rye and no-till cotton

    Science.gov (United States)

    Small grain cover crops offer opportunities for grazing but effects on following row crops are not well understood. From 1999 through 2008, stocker steers sequence grazed small grains in a 2-paddock rye-cotton-wheat-fallow- rye rotation. Treatments imposed on rye included 1) zero-grazing from 1999; ...

  5. Yields of Selected Catch Crops in Dry Conditions

    Directory of Open Access Journals (Sweden)

    Martina Handlířová

    2016-01-01

    Full Text Available Catch crops mainly reduce soil erosion and leaching of nutrients as well as enrich the soil organic matter. The aim of this research is to evaluate the yields of catch crops of Sinapis alba, Phacelia tanacetifolia, Fagopyrum esculentum, Carthamus tinctorius and Secale cereale v. multicaule, and thus determine the possible applicability of catch crops in areas with high average annual temperature and low precipitation totals. The small-plot field experiment was performed on clay-loam gleyic fluvisol at the Field Experimental Station in Žabčice, Southern Moravia, Czech Republic, within the period of 2006-2014. The catch crops were set up after winter wheat in mid-August. The results have shown a statistically significant difference among different catch crops in yield of dry matter and even among years. The yield of catch crops is mainly dependent on a sufficient supply of water in the soil and the appropriate amount and distribution of rainfall over the growing season. Sinapis alba and Phacelia tanacetifolia regularly reached the highest yields. High yields were also achieved with Fagopyrum esculentum. Due to the method of crop rotation in the Czech Republic, with a predominance of Brassica napus var. napus, it is inappropriate to include Sinapis alba. It is the best to grow Phacelia tanacetifolia and even Fagopyrum esculentum, or a mixture thereof, depending on the use of catch crops.

  6. Impact of rotating resonant magnetic perturbation fields on plasma edge electron density and temperature

    International Nuclear Information System (INIS)

    Stoschus, H.; Schmitz, O.; Frerichs, H.; Reiser, D.; Unterberg, B.; Lehnen, M.; Reiter, D.; Samm, U.; Jakubowski, M.W.

    2012-01-01

    Rotating resonant magnetic perturbation (RMP) fields impose a characteristic modulation to the edge electron density n e (r, t) and temperature T e (r, t) fields, which depends on the relative rotation f rel between external RMP field and plasma fluid. The n e (r, t) and T e (r, t) fields measured in the edge (r/a = 0.9–1.05) of TEXTOR L-mode plasmas are in close correlation with the local magnetic vacuum topology for low relative rotation f rel = −0.2 kHz. In comparison with the 3D neutral and plasma transport code EMC3-Eirene, this provides substantial experimental evidence that for low relative rotation level and high resonant field amplitudes (normalized radial field strength B r 4/1 /B t =2×10 -3 ), a stochastic edge with a remnant island chain dominated by diffusive transport exists. Radially outside a helical scrape-off layer, the so-called laminar zone embedded into a stochastic domain is found to exist. In contrast for high relative rotation of f rel = 1.8 kHz, the measured modulation of n e is shifted by π/2 toroidally with respect to the modelled vacuum topology. A pronounced flattening in T e (r) and a reduction in n e (r) is measured at the resonant flux surface and represents a clear signature for a magnetic island, which is phase shifted with respect to the vacuum island position. A correlated shift of the laminar zone radially outwards at the very plasma edge is observed suggesting that the actual near-field structure at the perturbation source is determined by the plasma response as well. (paper)

  7. Partitioning carbon fluxes from a Midwestern corn and soybean rotation system using footprint analysis

    Science.gov (United States)

    Dold, C.; Hatfield, J.; Prueger, J. H.; Wacha, K.

    2017-12-01

    Midwestern US agriculture is dominated by corn and soybean production. Corn has typically higher Net Ecosystem Exchange (NEE) than soybean due to increased carboxylation efficiency and different crop management. The conjoined NEE may be measured with eddy covariance (EC) stations covering both crops, however, it is often unclear what the contribution of each crop is, as the CO2 source area remains unknown. The aim of this study was to quantify the contribution of CO2 fluxes from each crop for a conventional corn-soybean rotation system from 2007 - 2015. Therefore, the combined CO2 flux of three adjacent fields with annual corn-soybean rotation was measured with a 9.1 m EC tower (Flux 30). In the center of two of these fields, additional EC towers (Flux 10 and Flux 11) were positioned above the corn and soybean canopy to validate Flux 30 NEE. For each EC system the annual 90% NEE footprint area was calculated, footprints were partitioned among fields, and NEE separated accordingly. The average annual 90% footprint area of Flux 30, and Flux 10/11 corn and soybean was estimated to 206, 11 and 7 ha, respectively. The annual average (±SE) NEE of Flux 30 was -693 ± 47 g CO2 m-2 yr-1, of which 83% out of 90% originated from the three adjacent fields. Corn and soybean NEE measured at Flux 10 and 11 was -1124 ± 95 and 173 ± 73 g CO2 m-2 yr-1, respectively, and 89% and 90% originated from these fields. That demonstrates, that Flux 30 represents the combined NEE of a corn-soybean rotation, and Flux 10 and 11 measured NEE from a single crop. However, the share of Flux 30 NEE originating from corn and soybean grown on the Flux 10/11 fields was -192 ± 16 and -205 ± 18 g CO2 m-2 yr-1, indicating a substantial difference to single crop NEE. While it was possible to measure the NEE of a corn-soybean rotation with a tall EC tower, footprint partitioning could not retrieve NEE for each crop, probably due to differences in measurement height and footprint source area.

  8. State-to-state dynamics at the gas-liquid metal interface: rotationally and electronically inelastic scattering of NO[2Π(1/2)(0.5)] from molten gallium.

    Science.gov (United States)

    Ziemkiewicz, Michael P; Roscioli, Joseph R; Nesbitt, David J

    2011-06-21

    Jet cooled NO molecules are scattered at 45° with respect to the surface normal from a liquid gallium surface at E(inc) from 1.0(3) to 20(6) kcal/mol to probe rotationally and electronically inelastic scattering from a gas-molten metal interface (numbers in parenthesis represent 1σ uncertainty in the corresponding final digits). Scattered populations are detected at 45° by confocal laser induced fluorescence (LIF) on the γ(0-0) and γ(1-1) A(2)Σ ← X(2)Π(Ω) bands, yielding rotational, spin-orbit, and λ-doublet population distributions. Scattering of low speed NO molecules results in Boltzmann distributions with effective temperatures considerably lower than that of the surface, in respectable agreement with the Bowman-Gossage rotational cooling model [J. M. Bowman and J. L. Gossage, Chem. Phys. Lett. 96, 481 (1983)] for desorption from a restricted surface rotor state. Increasing collision energy results in a stronger increase in scattered NO rotational energy than spin-orbit excitation, with an opposite trend noted for changes in surface temperature. The difference between electronic and rotational dynamics is discussed in terms of the possible influence of electron hole pair excitations in the conducting metal. While such electronically non-adiabatic processes can also influence vibrational dynamics, the γ(1-1) band indicates rotational energy transfer is compared from a hard cube model perspective with previous studies of NO scattering from single crystal solid surfaces. Despite a lighter atomic mass (70 amu), the liquid Ga surface is found to promote translational to rotational excitation more efficiently than Ag(111) (108 amu) and nearly as effectively as Au(111) (197 amu). The enhanced propensity for Ga(l) to transform incident translational energy into rotation is discussed in terms of temperature-dependent capillary wave excitation of the gas-liquid metal interface. © 2011 American Institute of Physics

  9. Energy crops for biogas plants. Lower Saxony; Energiepflanzen fuer Biogasanlagen. Niedersachsen

    Energy Technology Data Exchange (ETDEWEB)

    Aurbacher, J.; Benke, M.; Formowitz, B. (and others)

    2012-06-15

    In the brochure under consideration the Agency for Renewable Resources (Guelzow-Pruezen, Federal Republic of Germany) reports on the support of the implementation of different plant cultures in structure of plantations and crop rotation systems of companies under consideration of the Federal State Lower Saxony. The main chapters of this brochure are: Crops for the production of biogas; implementation in plantations; ensilage and biogas yields; economy of the cultivation of energy plants.

  10. Harvester development for new high yielding SRC crops and markets

    Energy Technology Data Exchange (ETDEWEB)

    Paulson, Mark

    2005-07-01

    This report describes the development of harvesting equipment for short rotation cultivation (SRC) crops produced in the UK that can produce fuel to a required specification in a single pass at a cost that is profitable for the grower while minimising the cost of the product. Details are given of the manufacture and installation of new components for large crop harvesting, and production of fuel suitable for co-firing in a coal combustion system using pulverised fuel and fuel suitable for gasification. The development of the drive chain to cope with the higher yielding crops, field tests on SRC crops, and determination of the most economic harvesting system are discussed along with the remanufacture of the chipping drum, and production of market chip samples. Harvesting guidance and an economic analysis of harvesting systems are presented.

  11. Harvester development for new high yielding SRC crops and markets

    International Nuclear Information System (INIS)

    Paulson, Mark

    2005-01-01

    This report describes the development of harvesting equipment for short rotation cultivation (SRC) crops produced in the UK that can produce fuel to a required specification in a single pass at a cost that is profitable for the grower while minimising the cost of the product. Details are given of the manufacture and installation of new components for large crop harvesting, and production of fuel suitable for co-firing in a coal combustion system using pulverised fuel and fuel suitable for gasification. The development of the drive chain to cope with the higher yielding crops, field tests on SRC crops, and determination of the most economic harvesting system are discussed along with the remanufacture of the chipping drum, and production of market chip samples. Harvesting guidance and an economic analysis of harvesting systems are presented

  12. Probing the Electronic Environment of Methylindoles using Internal Rotation and (14)N Nuclear Quadrupole Coupling.

    Science.gov (United States)

    Gurusinghe, Ranil M; Tubergen, Michael J

    2016-05-26

    High-resolution rotational spectra were recorded in the 10.5-21.0 GHz frequency range for seven singly methylated indoles. (14)N nuclear quadrupole hyperfine structure and spectral splittings arising from tunneling along the internal rotation of the methyl group were resolved for all indole species. The nuclear quadrupole coupling constants were used to characterize the electronic environment of the nitrogen atom, and the program XIAM was used to fit the barrier to internal rotation to the measured transition frequencies. The best fit barriers were found to be 277.1(2), 374.32(4), 414.(5), 331.6(2), 126.8675(15), 121.413(4), and 426(3) cm(-1) for 1-methylindole through 7-methylindole, respectively. The fitted barriers were found to be in good agreement with barriers calculated at the ωB97XD/6-311++G(d,p) level. The complete set of experimental barriers is compared to theoretical investigations of the origins of methyl torsional barriers and confirms that the magnitude of these barriers is an overall effect of individual hyperconjugative and structural interactions of many bonding/antibonding orbitals.

  13. Local analysis of strains and rotations for macromolecular electron microscopy maps

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Ramos, A.; Prieto, F.; Melero, R.; Martin-Benito, J.; Jonic, S.; Navas-Calvente, J.; Vargas, J.; Oton, J.; Abrishami, V.; Rosa-Trevin, J.L. de la; Gomez-Blanco, J.; Vilas, J.L.; Marabini, R.; Carazo, R.; Sorzano, C.O.S.

    2016-07-01

    Macromolecular complexes can be considered as molecular nano-machines that must have mobile parts in order to perform their physiological functions. The reordering of their parts is essential to execute their task. These rearrangements induce local strains and rotations which, after analyzing them, may provide relevant information about how the proteins perform their function. In this project these deformations of the macromolecular complexes are characterized, translating into a “mathematical language” the conformational changes of the complexes when they perform their function. Electron Microscopy (EM) volumes are analyzed using a method that uses B-splines as its basis functions. It is shown that the results obtained are consistent with the conformational changes described in their corresponding reference publications. (Author)

  14. Management of Soilborne Diseases in Strawberry Using Vegetable Rotations

    OpenAIRE

    Subbarao, Krishna V

    2007-01-01

    The influence of crop rotation on soilborne diseases and yield of strawberry (Fragaria × ananassa) was determined at a site infested with Verticillium dahliae microsclerotia and at another with no known history of V. dahliae infestation during 1997 to 2000. The rotations studied at the V. dahliae-infested site were (i) broccoli-broccoli-strawberry, (ii) Brussels sproutsstrawberry, and (iii) lettuce-lettuce-strawberry; the treatments at the site with no history of V. dahliae were (i) broccoli-...

  15. Water footprint of crop production for different crop structures in the Hebei southern plain, North China

    Directory of Open Access Journals (Sweden)

    Y. Chu

    2017-06-01

    Full Text Available The North China Plain (NCP has a serious shortage of freshwater resources, and crop production consumes approximately 75 % of the region's water. To estimate water consumption of different crops and crop structures in the NCP, the Hebei southern plain (HSP was selected as a study area, as it is a typical region of groundwater overdraft in the NCP. In this study, the water footprint (WF of crop production, comprised of green, blue and grey water footprints, and its annual variation were analyzed. The results demonstrated the following: (1 the WF from the production of main crops was 41.8 km3 in 2012. Winter wheat, summer maize and vegetables were the top water-consuming crops in the HSP. The water footprint intensity (WFI of cotton was the largest, and for vegetables, it was the smallest; (2 the total WF, WFblue, WFgreen and WFgrey for 13 years (2000–2012 of crop production were 604.8, 288.5, 141.3 and 175.0 km3, respectively, with an annual downtrend from 2000 to 2012; (3 winter wheat, summer maize and vegetables consumed the most groundwater, and their blue water footprint (WFblue accounted for 74.2 % of the total WFblue in the HSP; (4 the crop structure scenarios analysis indicated that, with approximately 20 % of arable land cultivated with winter wheat–summer maize in rotation, 38.99 % spring maize, 10 % vegetables and 10 % fruiters, a sustainable utilization of groundwater resources can be promoted, and a sufficient supply of food, including vegetables and fruits, can be ensured in the HSP.

  16. Organic farming and cover crops as an alternative to mineral fertilizers to improve soil physical properties

    Science.gov (United States)

    Sánchez de Cima, Diego; Luik, Anne; Reintam, Endla

    2015-10-01

    For testing how cover crops and different fertilization managements affect the soil physical properties in a plough based tillage system, a five-year crop rotation experiment (field pea, white potato, common barley undersown with red clover, red clover, and winter wheat) was set. The rotation was managed under four different farming systems: two conventional: with and without mineral fertilizers and two organic, both with winter cover crops (later ploughed and used as green manure) and one where cattle manure was added yearly. The measurements conducted were penetration resistance, soil water content, porosity, water permeability, and organic carbon. Yearly variations were linked to the number of tillage operations, and a cumulative effect of soil organic carbon in the soil as a result of the different fertilization amendments, organic or mineral. All the systems showed similar tendencies along the three years of study and differences were only found between the control and the other systems. Mineral fertilizers enhanced the overall physical soil conditions due to the higher yield in the system. In the organic systems, cover crops and cattle manure did not have a significant effect on soil physical properties in comparison with the conventional ones, which were kept bare during the winter period. The extra organic matter boosted the positive effect of crop rotation, but the higher number of tillage operations in both organic systems counteracted this effect to a greater or lesser extent.

  17. Greenhouse gas emissions and global warming potential of traditional and diversified tropical rice rotation systems.

    Science.gov (United States)

    Weller, Sebastian; Janz, Baldur; Jörg, Lena; Kraus, David; Racela, Heathcliff S U; Wassmann, Reiner; Butterbach-Bahl, Klaus; Kiese, Ralf

    2016-01-01

    Global rice agriculture will be increasingly challenged by water scarcity, while at the same time changes in demand (e.g. changes in diets or increasing demand for biofuels) will feed back on agricultural practices. These factors are changing traditional cropping patterns from double-rice cropping to the introduction of upland crops in the dry season. For a comprehensive assessment of greenhouse gas (GHG) balances, we measured methane (CH4 )/nitrous oxide (N2 O) emissions and agronomic parameters over 2.5 years in double-rice cropping (R-R) and paddy rice rotations diversified with either maize (R-M) or aerobic rice (R-A) in upland cultivation. Introduction of upland crops in the dry season reduced irrigation water use and CH4 emissions by 66-81% and 95-99%, respectively. Moreover, for practices including upland crops, CH4 emissions in the subsequent wet season with paddy rice were reduced by 54-60%. Although annual N2 O emissions increased two- to threefold in the diversified systems, the strong reduction in CH4 led to a significantly lower (P < 0.05) annual GWP (CH4  + N2 O) as compared to the traditional double-rice cropping system. Measurements of soil organic carbon (SOC) contents before and 3 years after the introduction of upland crop rotations indicated a SOC loss for the R-M system, while for the other systems SOC stocks were unaffected. This trend for R-M systems needs to be followed as it has significant consequences not only for the GWP balance but also with regard to soil fertility. Economic assessment showed a similar gross profit span for R-M and R-R, while gross profits for R-A were reduced as a consequence of lower productivity. Nevertheless, regarding a future increase in water scarcity, it can be expected that mixed lowland-upland systems will expand in SE Asia as water requirements were cut by more than half in both rotation systems with upland crops. © 2015 John Wiley & Sons Ltd.

  18. Influence of Seeding Ratio, Planting Date, and Termination Date on Rye-Hairy Vetch Cover Crop Mixture Performance under Organic Management

    OpenAIRE

    Lawson, Andrew; Cogger, Craig; Bary, Andy; Fortuna, Ann-Marie

    2015-01-01

    Cover crop benefits include nitrogen accumulation and retention, weed suppression, organic matter maintenance, and reduced erosion. Organic farmers need region-specific information on winter cover crop performance to effectively integrate cover crops into their crop rotations. Our research objective was to compare cover crop seeding mixtures, planting dates, and termination dates on performance of rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) monocultures and mixtures in the ma...

  19. Effect of Nutrient Management Planning on Crop Yield, Nitrate Leaching and Sediment Loading in Thomas Brook Watershed

    Science.gov (United States)

    Amon-Armah, Frederick; Yiridoe, Emmanuel K.; Ahmad, Nafees H. M.; Hebb, Dale; Jamieson, Rob; Burton, David; Madani, Ali

    2013-11-01

    Government priorities on provincial Nutrient Management Planning (NMP) programs include improving the program effectiveness for environmental quality protection, and promoting more widespread adoption. Understanding the effect of NMP on both crop yield and key water-quality parameters in agricultural watersheds requires a comprehensive evaluation that takes into consideration important NMP attributes and location-specific farming conditions. This study applied the Soil and Water Assessment Tool (SWAT) to investigate the effects of crop and rotation sequence, tillage type, and nutrient N application rate on crop yield and the associated groundwater leaching and sediment loss. The SWAT model was applied to the Thomas Brook Watershed, located in the most intensively managed agricultural region of Nova Scotia, Canada. Cropping systems evaluated included seven fertilizer application rates and two tillage systems (i.e., conventional tillage and no-till). The analysis reflected cropping systems commonly managed by farmers in the Annapolis Valley region, including grain corn-based and potato-based cropping systems, and a vegetable-horticulture system. ANOVA models were developed and used to assess the effects of crop management choices on crop yield and two water-quality parameters (i.e., leaching and sediment loading). Results suggest that existing recommended N-fertilizer rate can be reduced by 10-25 %, for grain crop production, to significantly lower leaching ( P > 0.05) while optimizing the crop yield. The analysis identified the nutrient N rates in combination with specific crops and rotation systems that can be used to manage leaching while balancing impacts on crop yields within the watershed.

  20. Ensuring sustainable grain legume-cereal cropping systems

    DEFF Research Database (Denmark)

    Bedoussac, Laurent; Journet, E-P; Hauggaard-Nielsen, Henrik

    2017-01-01

    health makes them a key rotation crop in the sustainable intensification and diversification of smallholder farming. This makes grain legumes a key food security crop. However, yields in developing countries are low as a result of such factors as the need for improved varieties of seed, poor seed......Grain legumes are widely cultivated, particularly for their dry seeds (known as pulses). Grain legumes are an important crop for a number of reasons. They are a rich source of protein and fibre, minerals and vitamins. In addition, their rapid growth and ability to fix nitrogen and improve soil...... distribution, the impact of pests and diseases, as well as vulnerability to poor soils, drought and other effects of climate change. This chapter summarises data from over 50 field experiments undertaken since 2001 on cereal-grain legume intercropping in 13 sites in southern and western France as well...

  1. Spin rotation after a spin-independent scattering. Spin properties of an electron gas in a solid

    International Nuclear Information System (INIS)

    Zayets, V.

    2014-01-01

    It is shown that spin direction of an electron may not be conserved after a spin-independent scattering. The spin rotations occur due to a quantum-mechanical fact that when a quantum state is occupied by two electrons of opposite spins, the total spin of the state is zero and the spin direction of each electron cannot be determined. It is shown that it is possible to divide all conduction electrons into two group distinguished by their time-reversal symmetry. In the first group the electron spins are all directed in one direction. In the second group there are electrons of all spin directions. The number of electrons in each group is conserved after a spin-independent scattering. This makes it convenient to use these groups for the description of the magnetic properties of conduction electrons. The energy distribution of spins, the Pauli paramagnetism and the spin distribution in the ferromagnetic metals are described within the presented model. The effects of spin torque and spin-torque current are described. The origin of spin-transfer torque is explained within the presented model

  2. Implications of observed and simulated soil carbon sequestration for management options in corn-based rotations

    Science.gov (United States)

    Managing cropping systems to sequester soil organic carbon (SOC) improves soil health and a system’s resiliency to impacts of changing climate. Our objectives were to 1) monitor SOC from a bio-energy cropping study in central Pennsylvania that included a corn-soybean-alfalfa rotation, switchgrass, a...

  3. Implications of observed and simulated soil carbon sequestration for management options in corn-based rotations

    Science.gov (United States)

    Managing cropping systems to sequester soil organic carbon (SOC) improves soil health and a system’s resiliency to impacts of changing climate. Our objectives were to 1) monitor SOC from a bio-energy cropping study in central Pennsylvania that included a corn-soybean-alfalfa rotation, switchgrass, ...

  4. On the stability of rotational discontinuities

    International Nuclear Information System (INIS)

    Richter, P.; Scholer, M.

    1989-01-01

    The stability of symmetric rotational discontinuities in which the magnetic field rotates by 180 degree is investigated by means of a one-dimensional self-consistent hybrid code. Rotational discontinuities with an angle Θ > 45 degree between the discontinuity normal direction and the upstream magnetic field are found to be relatively stable. The discontinuity normal is in the x direction and the initial magnetic field has finite y component only in the transition region. In the case of the ion (left-handed) sense of rotation of the tangential magnetic field, the transition region does not broaden with time. In the case of the electron (right-handed) sense of rotation, a damped wavetrain builds up in the B y component downstream of the rotational discontinuity and the discontinuity broadens with time. Rotational discontinuities with smaller angles, Θ, are unstable. Examples for a rotational discontinuity with Θ = 30 degree and the electron sense of rotation as well as a rotational discontinuity with Θ = 15 degree and the ion sense of rotation show that these discontinuities into waves. These waves travel approximately with Alfven velocity in the upstream direction and are therefore phase standing in the simulation system. The magnetic hodograms of these disintegrated discontinuities are S-shaped. The upstream portion of the hodogram is always right-handed; the downstream portion is always left-handed

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

    International Nuclear Information System (INIS)

    Alluvione, Francesco; Moretti, Barbara; Sacco, Dario; Grignani, Carlo

    2011-01-01

    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.

  6. Effects of different cropping systems and weed management methods on free energy and content of pigments in maize

    Directory of Open Access Journals (Sweden)

    Igor Spasojević

    2014-03-01

    Full Text Available Rotation is a cropping system that has many advantages and ensures better crop growth and yielding. Its combinination with other cropping measures can ensure optimal crop density for maximal growth and photosynthesis efficiency. The aim of this study was to investigate the influence of different cropping systems: monoculture and two rotations, including maize, wheat and soybean (MSW and MWS, and different weed management methods (weed removal by hoeing, application of a full recommended herbicide dose (RD and half that dose (0.5 RD, and weedy check on weed biomass and maize growth parameters - leaf area index (LAI, free energy, contents of chlorophyll and carotenoids, grain yield, and their possible relationships in two fields of the maize hybrids ZP 677 (H1 and ZP 606 (H2. The lowest LAI and grain yield were found in monoculture, particularly in weedy check, which had relatively high weed infestation. Higher weed biomass was also observed in herbicide treated plots in monoculture. Such high competition pressure indicates a stress reflected on reduced LAI and chlorophyll content, and increased free energy and content of carotenoids. On the other hand, rotation, particularly if it is combined with the application of herbicides or hoeing, had a positive impact on yielding potential by increasing LAI and the contents of chlorophyll and carotenoids, and decreasing free energy.

  7. Optimising an integrated crop-livestock farm using risk programming

    Directory of Open Access Journals (Sweden)

    SE Visagie

    2004-06-01

    Full Text Available Numerous studies have analysed farm planning decisions focusing on producer risk preferences. Few studies have focussed on the farm planning decisions in an integrated croplivestock farm context. Income variability and means of managing risk continues to receive much attention in farm planning research. Different risk programming models have attempted to focus on minimising the income variability of farm activities. This study attempts to identify the optimal mix of crops and the number of animals the farm needs to keep in the presence of crop production risk for a range of risk levels. A mixed integer linear programming model was developed to model the decision environment faced by an integrated crop-livestock farmer. The deviation of income from the expected value was used as a measure of risk. A case study is presented with representative data from a farm in the Swartland area. An investigation of the results of the model under different constraints shows that, in general, strategies that depend on crop rotation principles are preferred to strategies that follow mono-crop production practices.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-01

    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)

  9. Impact of preceding crop on alfalfa competitiveness with weeds

    Science.gov (United States)

    Organic producers would like to include no-till practices in their farming systems. We are seeking to develop a continuous no-till system for organic farming, based on a complex rotation that includes a 3-year sequence of alfalfa. In this study, we evaluated impact of preceding crop on weed infest...

  10. Seasonal Soil Nitrogen Mineralization within an Integrated Crop and Livestock System in Western North Dakota, USA

    Science.gov (United States)

    Landblom, Douglas; Senturklu, Songul; Cihacek, Larry; Pfenning, Lauren; Brevik, Eric C.

    2015-04-01

    Protecting natural resources while maintaining or maximizing crop yield potential is of utmost importance for sustainable crop and livestock production systems. Since soil organic matter and its decomposition by soil organisms is at the very foundation of healthy productive soils, systems research at the North Dakota State University Dickinson Research Extension Center is evaluating seasonal soil nitrogen fertility within an integrated crop and livestock production system. The 5-year diverse crop rotation is: sunflower (SF) - hard red spring wheat (HRSW) - fall seeded winter triticale-hairy vetch (THV; spring harvested for hay)/spring seeded 7-species cover crop (CC) - Corn (C) (85-90 day var.) - field pea-barley intercrop (PBY). The HRSW and SF are harvested as cash crops and the PBY, C, and CC are harvested by grazing cattle. In the system, yearling beef steers graze the PBY and C before feedlot entry and after weaning, gestating beef cows graze the CC. Since rotation establishment, four crop years have been harvested from the crop rotation. All crops have been seeded using a JD 1590 no-till drill except C and SF. Corn and SF were planted using a JD 7000 no-till planter. The HRSW, PBY, and CC were seeded at a soil depth of 3.8 cm and a row width of 19.1 cm. Seed placement for the C and SF crops was at a soil depth of 5.1 cm and the row spacing was 0.762 m. The plant population goal/ha for C, SF, and wheat was 7,689, 50,587, and 7,244 p/ha, respectively. During the 3rd cropping year, soil bulk density was measured and during the 4th cropping year, seasonal nitrogen fertility was monitored throughout the growing season from June to October. Seasonal nitrate nitrogen (NO3-N), ammonium nitrogen (NH4-N), total season mineral nitrogen (NO3-N + NH4-N), cropping system NO3-N, and bulk density were measured in 3 replicated non-fertilized field plot areas within each 10.6 ha triple replicated crop fields. Within each plot area, 6 - 20.3 cm x 0.61 m aluminum irrigation

  11. On weed competition and population dynamics : considerations for crop rotations & organic farming

    NARCIS (Netherlands)

    Mertens, S.K.

    2002-01-01

    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 ,

  12. Effect of Winter Cover Crops on Soil Nitrogen Availability, Corn Yield, and Nitrate Leaching

    OpenAIRE

    Kuo, S.; Huang, B.; Bembenek, R.

    2001-01-01

    Biculture of nonlegumes and legumes could serve as cover crops for increasing main crop yield, while reducing NO3 leaching. This study, conducted from 1994 to 1999, determined the effect of monocultured cereal rye (Secale cereale L.), annual ryegrass (Lolium multiflorum), and hairy vetch (Vicia villosa), and bicultured rye/vetch and ryegrass/vetch on N availability in soil, corn (Zea mays L.) yield, and NO3-N leaching in a silt loam soil. The field had been in corn and cover crop rotation sin...

  13. Residual soil nitrate content and profitability of five cropping systems in northwest Iowa.

    Directory of Open Access Journals (Sweden)

    Robert L De Haan

    Full Text Available Many communities in the Midwestern United States obtain their drinking water from shallow alluvial wells that are vulnerable to contamination by NO3-N from the surrounding agricultural landscape. The objective of this research was to assess cropping systems with the potential to produce a reasonable return for farmers while simultaneously reducing the risk of NO3-N movement into these shallow aquifers. From 2009 to 2013 we conducted a field experiment in northwest Iowa in which we evaluated five cropping systems for residual (late fall soil NO3-N content and profitability. Soil samples were taken annually from the top 30 cm of the soil profile in June and August, and from the top 180 cm in November (late fall. The November samples were divided into 30 cm increments for analysis. Average residual NO3-N content in the top 180 cm of the soil profile following the 2010 to 2013 cropping years was 134 kg ha-1 for continuous maize (Zea mays L. with a cereal rye (Secale cereale L. cover crop, 18 kg ha-1 for perennial grass, 60 kg ha-1 for a three year oat (Avena sativa L.-alfalfa (Medicago sativa L.-maize rotation, 85 kg ha-1 for a two year oat/red clover (Trifolium pratense L.-maize rotation, and 90 kg ha-1 for a three year soybean (Glycine max (L. Merr.-winter wheat (Triticum aestivum L.-maize rotation. However, residual NO3-N in the 90 to 180 cm increment of the soil profile was not significantly higher in the oat-alfalfa-maize cropping system than the perennial grass system. For 2010 to 2013, average profit ($ ha-1 yr-1 was 531 for continuous corn, 347 for soybean-winter wheat-maize, 264 for oat-alfalfa-maize, 140 for oat/red clover-maize, and -384 (loss for perennial grass. Considering both residual soil NO3-N and profitability data, the oat-alfalfa-maize rotation performed the best in this setting. However, given current economic pressures widespread adoption is likely to require changes in public policy.

  14. Development of Rotational Smart Lighting Control System for Plant Factory

    OpenAIRE

    Won-Sub Lee; Sung-Gaun Kim

    2012-01-01

    Rotational Smart Lighting Control System can supply the quantity of lighting which is required to run plants by rotating few LED and Fluorescent instead of that are used in the existing plant factories.The initial installation of the existing plants factory is expensive, so in order to solve the problem with smart lighting control system was developed. The beam required intensity for the growth of crops, Photosynthetic Photon Flux Density(PPFD)is calculated; and the numbe...

  15. Short rotation coppice for energy production: hydrological guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.L.

    2003-07-01

    This report provides hydrological guidelines for growers, land and water resource managers, environmental groups and other parties interested in utilising short rotation coppice (SRC) for energy production. The aim of the report is to help interested parties decide if a location is suitable for SRC planting by considering whether potential hydrological impacts will have an adverse effect on crop productivity and yield. The guidelines consider: the water use of SRC compared with other crops; the factors governing water use; the water requirements for a productive crop; and the likely impacts on the availability and quantity of water. The report points out that there are still gaps in our knowledge of the processes controlling the water use and growth of SRC and notes that, in some situations, there will be considerable uncertainty in predictions.

  16. Complete snake and rotator schemes for spin polarization in proton rings and large electron rings

    International Nuclear Information System (INIS)

    Steffen, K.

    1983-11-01

    In order to maintain spin polarization in proton rings and large electron rings, some generalized Siberian Snake scheme may be required to make the spin tune almost independent of energy and thus avoid depolarizing resonances. The practical problem of finding such schemes that, at reasonable technical effort, can be made to work over large energy ranges has been addressed before and is here revisited in a broadened view and with added new suggestions. As a result, possibly optimum schemes for electron rings (LEP) and proton rings are described. In the proposed LEP scheme, spin rotation is devised such that, at the interaction points, the spin direction is longitudinal as required for experiments. (orig.)

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

    International Nuclear Information System (INIS)

    Graham, R.L.; Wright, L.L.; Turhollow, A.F.

    1992-01-01

    Short-rotation woody crops (SRWC) could potentially displace fossil fuels and thus mitigate CO 2 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 10 6 ha), it is calculated that SRWC energy could displace 33.2 to 73.1 x 10 6 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 10 6 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 10 6 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

  18. Glyphosate sustainability in South American cropping systems.

    Science.gov (United States)

    Christoffoleti, Pedro J; Galli, Antonio J B; Carvalho, Saul J P; Moreira, Murilo S; Nicolai, Marcelo; Foloni, Luiz L; Martins, Bianca A B; Ribeiro, Daniela N

    2008-04-01

    South America represents about 12% of the global land area, and Brazil roughly corresponds to 47% of that. The major sustainable agricultural system in South America is based on a no-tillage cropping system, which is a worldwide adopted agricultural conservation system. Societal benefits of conservation systems in agriculture include greater use of conservation tillage, which reduces soil erosion and associated loading of pesticides, nutrients and sediments into the environment. However, overreliance on glyphosate and simpler cropping systems has resulted in the selection of tolerant weed species through weed shifts (WSs) and evolution of herbicide-resistant weed (HRW) biotypes to glyphosate. It is a challenge in South America to design herbicide- and non-herbicide-based strategies that effectively delay and/or manage evolution of HRWs and WSs to weeds tolerant to glyphosate in cropping systems based on recurrent glyphosate application, such as those used with glyphosate-resistant soybeans. The objectives of this paper are (i) to provide an overview of some factors that influence WSs and HRWs to glyphosate in South America, especially in Brazil, Argentina and Paraguay soybean cropped areas; (ii) to discuss the viability of using crop rotation and/or cover crops that might be integrated with forage crops in an economically and environmentally sustainable system; and (iii) to summarize the results of a survey of the perceptions of Brazilian farmers to problems with WSs and HRWs to glyphosate, and the level of adoption of good agricultural practices in order to prevent or manage it. Copyright (c) 2008 Society of Chemical Industry.

  19. Effects of alternative cropping systems on globe artichoke qualitative traits.

    Science.gov (United States)

    Spanu, Emanuela; Deligios, Paola A; Azara, Emanuela; Delogu, Giovanna; Ledda, Luigi

    2018-02-01

    Traditionally, globe artichoke cultivation in the Mediterranean basin is based on monoculture and on use of high amounts of nitrogen fertiliser. This raises issues regarding its compatibility with sustainable agriculture. We studied the effect of one typical conventional (CONV) and two alternative cropping systems [globe artichoke in sequence with French bean (NCV1), or in biannual rotation (NCV2) with cauliflower and with a leguminous cover crop in inter-row spaces] on yield, polyphenol and mineral content of globe artichoke heads over two consecutive growing seasons. NCV2 showed statistical differences in terms of fresh product yield with respect to the monoculture systems. In addition, the dihydroxycinnamic acids and dicaffeoylquinic acids of non-conventional samples were one-fold significantly higher than the conventional one. All the samples reported good mineral content, although NCV2 achieved a higher Fe content than conventional throughout the two seasons. After two and three dates of sampling, the CONV samples showed the highest levels of K content. In our study, an acceptable commercial yield and quality of 'Spinoso sardo' were achieved by shifting the common conventional agronomic management to more sustainable ones, by means of an accurate choice of cover crop species and rotations introduced in the systems. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  20. Green Gram Rotation Effects on Maize Growth Parameters and Soil Quality in Myanmar

    Directory of Open Access Journals (Sweden)

    Myo Kywe

    2008-10-01

    Full Text Available At present maize–green gram crop rotations are not widely practiced among farmers in Myanmar. However, this cropping system might become more popular in the future given raising prices for green gram and maize grain and scarcity of mineral nitrogen (N fertilizers in this Asian country. The results of a cropping systems experiment with continuous maize versus a green gram-maize rotation, manure application (0 and 2 t ha−1 and phosphorus (P fertilization (0 and 15 kg P ha−1 in each of five consecutive seasons revealed a strong decline in total dry matter and grains yields for both crops irrespective of the treatment. Treatment effects on yield components, nutrient concentrations, mycorrhizal infection and nematode infestation were small or negligible. The data show that in addition to manure used at 2 t ha−1, application of mineral N fertilizers is essential to maintain particularly maize yields. A comparison of different green gram cultivars did not indicate genotype specific effects on maize growth. The incorporation of legume residues, unless they are used as animal feed, is recommended to increase the recycling of N and to balance N fluxes when green gram is cultivated for seed.

  1. Zero-point vibrational effects on optical rotation

    DEFF Research Database (Denmark)

    Ruud, K.; Taylor, P.R.; Åstrand, P.-O.

    2001-01-01

    We investigate the effects of molecular vibrations on the optical rotation in two chiral molecules, methyloxirane and trans-2,3-dimethylthiirane. It is shown that the magnitude of zero-point vibrational corrections increases as the electronic contribution to the optical rotation increases....... Vibrational effects thus appear to be important for an overall estimate of the molecular optical rotation, amounting to about 20-30% of the electronic counterpart. We also investigate the special case of chirality introduced in a molecule through isotopic substitution. In this case, the zero-point vibrational...

  2. Soil denitrifier community size changes with land use change to perennial bioenergy cropping systems

    Science.gov (United States)

    Thompson, Karen A.; Deen, Bill; Dunfield, Kari E.

    2016-10-01

    Dedicated biomass crops are required for future bioenergy production. However, the effects of large-scale land use change (LUC) from traditional annual crops, such as corn-soybean rotations to the perennial grasses (PGs) switchgrass and miscanthus, on soil microbial community functioning is largely unknown. Specifically, ecologically significant denitrifying communities, which regulate N2O production and consumption in soils, may respond differently to LUC due to differences in carbon (C) and nitrogen (N) inputs between crop types and management systems. Our objective was to quantify bacterial denitrifying gene abundances as influenced by corn-soybean crop production compared to PG biomass production. A field trial was established in 2008 at the Elora Research Station in Ontario, Canada (n  =  30), with miscanthus and switchgrass grown alongside corn-soybean rotations at different N rates (0 and 160 kg N ha-1) and biomass harvest dates within PG plots. Soil was collected on four dates from 2011 to 2012 and quantitative PCR was used to enumerate the total bacterial community (16S rRNA) and communities of bacterial denitrifiers by targeting nitrite reductase (nirS) and N2O reductase (nosZ) genes. Miscanthus produced significantly larger yields and supported larger nosZ denitrifying communities than corn-soybean rotations regardless of management, indicating large-scale LUC from corn-soybean to miscanthus may be suitable in variable Ontario climatic conditions and under varied management, while potentially mitigating soil N2O emissions. Harvesting switchgrass in the spring decreased yields in N-fertilized plots, but did not affect gene abundances. Standing miscanthus overwinter resulted in higher 16S rRNA and nirS gene copies than in fall-harvested crops. However, the size of the total (16S rRNA) and denitrifying bacterial communities changed differently over time and in response to LUC, indicating varying controls on these communities.

  3. Field assessment of the relative agronomic effectiveness of phosphate rock materials in a soybean - Maize crop rotation using 32P isotope techniques

    International Nuclear Information System (INIS)

    Mahisarakul, J.; Siripaibool, C.; Claimon, J.; Pakkong, P.

    2002-01-01

    Field experiments were conducted at Phrabudhabart Field Crop Research Station, Lopbur Province during the period 1995-1997 to determine the relative agronomic effectiveness (RAE) in a soybean- maize crop rotation using 32 P isotope techniques. The soil of the experimental site was the Pakchong soil series (Oxic Paleustults). Four PRs were applied at 120 kg P ha -1 , namely Algerian PR (ARPR), North Carolina PR from USA (NCPR), Petchaburi PR from Thailand (PBPR) and Ratchaburi PR from Thailand (RBPR) and TSP was added at three rates (40, 60, 120 kg P ha -1 ). For the first year harvest, soybeans absorbed more P from TSP fertilizer (% FPU) applied at 40 kg P ha -1 than maize, but there was no yield response. Among four PRs, North Carolina phosphate rock (NCPR) gave the highest % Pdff as well as the highest RAE. Maize was planted after soybean to study the residual effect of TSP and PRs. The results were the same as in soybean. In the second year (1996) the grain yield of soybean was higher than in the first year (1995), and there was significant response to P from TSP. The RAE of NCPR was very high. Maize showed the opposite results. In this case Algerian PR (ARPR) had the highest RAE. In 1997, TSP and six PRs (same four used in 1995 and 1996, Morocco PR (MCPR), and Lumphun PR (LPPR)) were applied at 60 kg P ha -1 . Phosphate rocks were applied either alone or in combination with TSP (50:50). Application of TSP resulted in high yields of soybean. In terms of RAE the P sources ranked as follows: LPPR+TSP>ARPR>LPPR> MCPR>NCPR+TSP>NCPR. The residual effect of P on the following maize crop resulted in a high RAE for MCPR and LPPR. It was concluded that TSP should be applied to every crop. The reactivity of PRs in the first and the second year experiments were: ARPR>NCPR>RBPR>PBPR. Morocco PR and LPPR were also reactive PRs in the third experiment. The combination of PR and TSP resulted in better P uptake (%Pdff). (author)

  4. An identification of potential new herbicides for short rotation coppice (Task 4). Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This report summarises the findings of a project to identify potential new herbicides and their suitability for weed control in commercial short rotation coppice (SRC) crops, and to establish the safety of the crops. The arrangements for the use of 'off-label' pesticides, which are permitted for use on other crops, on SRC are discussed along with the importance of the use of laboratory pot trials and field trials. Several herbicides are proposed for larger scale field trials.

  5. Land use change and crop rotation analysis of a government well district in Rashda village – Dakhla Oasis, Egypt based on satellite data

    Directory of Open Access Journals (Sweden)

    H. Kato

    2012-12-01

    The land use change analysis showed that the extension of cultivated land was already completed by the 1980s in the North and South subdistricts, after which it spread toward the West. Because the altitude in the West subdistrict is lower than the wells, irrigation water could be distributed adequately if the condition of the irrigation channel was well maintained. The relationship between the irrigation level and plant production was not favorable in the West compared with other subdistricts. The cultivated area in the West district has been increasing since the 1970s. According to the crop rotation analysis, the different productivity of the subdistricts was caused by several factors, including the land altitude and the distance from the well, as well as other factors such as social relationships in the village.

  6. Effect of winter cover crops on nematode population levels in north Florida.

    Science.gov (United States)

    Wang, K-H; McSorley, R; Gallaher, R N

    2004-12-01

    Two experiments were conducted in north-central Florida to examine the effects of various winter cover crops on plant-parasitic nematode populations through time. In the first experiment, six winter cover crops were rotated with summer corn (Zea mays), arranged in a randomized complete block design. The cover crops evaluated were wheat (Triticum aestivum), rye (Secale cereale), oat (Avena sativa), lupine (Lupinus angustifolius), hairy vetch (Vicia villosa), and crimson clover (Trifolium incarnatum). At the end of the corn crop in year 1, population densities of Meloidogyne incognita were lowest on corn following rye or oat (P rye or lupine was planted into field plots with histories of five tropical cover crops: soybean (Glycine max), cowpea (Vigna unguiculata), sorghum-sudangrass (Sorghum bicolor x S. sudanense), sunn hemp (Crotalaria juncea), and corn. Population densities of M. incognita and Helicotylenchus dihystera were affected by previous tropical cover crops (P cover crops present at the time of sampling. Plots planted to sunn hemp in the fall maintained the lowest M. incognita and H. dihystera numbers. Results suggest that winter cover crops tested did not suppress plant-parasitic nematodes effectively. Planting tropical cover crops such as sunn hemp after corn in a triple-cropping system with winter cover crops may provide more versatile nematode management strategies in northern Florida.

  7. 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)

    Edmilson José Ambrosano

    2010-12-01

    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

  8. Pigeon Pea and Cowpea-Based Cropping Systems Improve Vesicular Arbuscular Mycorrhizal Fungal Colonisation of Subsequent Maize on the Alfisols in Central Malawi

    Directory of Open Access Journals (Sweden)

    Keston O. W. Njira

    2017-01-01

    Full Text Available Mycorrhizal associations contribute to the sustainability of crop production systems through their roles in nutrient cycling and other benefits in the soil-plant ecosystems. A two-year study was conducted on the Alfisols of Lilongwe and Dowa districts, Central Malawi, to assess the vesicular-arbuscular mycorrhizal (VAM fungal colonisation levels in pigeon pea, cowpea, and maize grown in sole cropping, legume-cereal, and legume-legume intercropping systems and in the maize grown in short rotation (year 2 as influenced by the previous cropping systems and N fertilizer application. The gridline intersect method was used to assess the VAM fungal colonisation levels. Results showed that all treatments that included legumes whether grown as sole crop, in legume-cereal or in legume-legume cropping systems in the previous year, had significantly higher (P < 0.05 VAM fungal colonisation of the rotational maize crop roots by a range 39% to 50% and 19% to 47% than those in maize supplied and not supplied with N fertilizer, respectively, in a maize-maize short rotation, at the Lilongwe site. A similar trend was reported for the Dowa site. Furthermore, there were positive correlations between VAM fungal colonisation and the plant P content, dry matter yield, and nodule numbers. Further studies may help to assess the diversity of VAM fungal species in Malawi soils and identify more adaptive ones for inoculation studies.

  9. Air-quality and Climatic Consequences of Bioenergy Crop Cultivation

    Science.gov (United States)

    Porter, William Christian

    Bioenergy is expected to play an increasingly significant role in the global energy budget. In addition to the use of liquid energy forms such as ethanol and biodiesel, electricity generation using processed energy crops as a partial or full coal alternative is expected to increase, requiring large-scale conversions of land for the cultivation of bioenergy feedstocks such as cane, grasses, or short rotation coppice. With land-use change identified as a major contributor to changes in the emission of biogenic volatile organic compounds (BVOCs), many of which are known contributors to the pollutants ozone (O 3) and fine particulate matter (PM2.5), careful review of crop emission profiles and local atmospheric chemistry will be necessary to mitigate any unintended air-quality consequences. In this work, the atmospheric consequences of bioenergy crop replacement are examined using both the high-resolution regional chemical transport model WRF/Chem (Weather Research and Forecasting with Chemistry) and the global climate model CESM (Community Earth System Model). Regional sensitivities to several representative crop types are analyzed, and the impacts of each crop on air quality and climate are compared. Overall, the high emitting crops (eucalyptus and giant reed) were found to produce climate and human health costs totaling up to 40% of the value of CO 2 emissions prevented, while the related costs of the lowest-emitting crop (switchgrass) were negligible.

  10. Productivity of clay tailings from phosphate mining: 3. Grain crops

    International Nuclear Information System (INIS)

    Mislevy, P.; Blue, W.G.; Roessler, C.E.; Martin, F.G.

    1991-01-01

    A split-fold field experiment was conducted to study forage and grain yield, forage quality, plant nutrient concentrations, changes in soil nutrients, and 226 Ra contents of four grain crops in various rotations. The crop rotations (1) corn (Zea mays L. Jacques 247)-sunflower (Helianthus annuus L. Cargil 205), (2) sunflower-grain sorghum (Sorghum bicolor L, Moench Northrup King Savanna 5), (3) soybean (Glycine max L. Merr. Williams 80)-grain sorghum, and (4) grain sorghum-soybean (University of Florida V-1) were grown on a dry phosphatic clay with and without a 50-mm surface layer of quartz-sand tailings. Results show that corn and grain sorghum produced highest forage yields and highest grain yields per harvest, respectively. Soybean harvested for forage (Crop 1) contained the highest crude protein and in vitro organic matter digestibility. Concentrations of P, K, Ca, Mg, and Fe in most of the forages were adequate for the diets of beef cattle, while those of Mn, Cu and Zn were low. Mehlich I-extractable soil, Ca, and Mg were considered very high and changed little over the 4-yr production period. Application of 50 mm of sand tailings tended to increase Mehlich I-extractable P, Ca, Mn, Cu, Zn, and Fe. Radium-226 concentration in the forage of all grain crops averaged 8.5 Bq kg -1 , which was about 17 times higher than that in the grain of the same crops. Concentrations of 226 Ra in the forage and grain were 1.1% and 0.09% of the concentration in clay respectively. These data indicate that phosphatic clays can be a valuable resource for the production of corn and sorghum grain that contain low concentrations of 226 Ra

  11. Energy plants increasingly important. Scientific results and practical experiences on the production of biogas plants and short rotation coppices. Symposium; Energiepflanzen im Aufwind. Wissenschaftliche Ergebnisse und praktische Erfahrungen zur Produktion von Biogaspflanzen und Feldholz. Fachtagung

    Energy Technology Data Exchange (ETDEWEB)

    Heiermann, M.; Scholz, V.; Foltan, H. (comps.)

    2007-05-15

    The conference proceedings contain 15 contributions on energy plants: energy plant production in Germany - developments and research activities; potentials and constraints of cultivating energy crops; environmental aspects of production and utilization of energy plants; costs of energy crop supply; crops for the biogas production in the territory of Brandenburg; mixed cropping systems on sandy soils - alternative cropping strategies; impact of ensiling process on biogas production - recent research results; solid state anaerobic digestion of renewable biomass sources - state of research and development; energy crops as feedstock in a biogas plant; proffer and demand of wood fuel in the State of Brandenburg; regulatory framework of growing short rotation coppice; mechanization of SRC production; 20 years of short rotation coppice; willow production and marketing in Denmark; short rotation coppice production in Italy.

  12. to Phosphorus Fertilization, Crop Sequence and Tillage Management

    Directory of Open Access Journals (Sweden)

    Xiaopeng Gao

    2012-01-01

    Full Text Available Field experiments were conducted at two locations in Manitoba, Canada, to determine the effect of crop rotation, phosphorus (P fertilization and tillage on grain yield and grain concentrations of Cd and Zn in durum wheat (Triticum durum L.. Compared to conventional tillage (CT, reduced tillage (RT management decreased grain Cd and increased grain yield and grain Zn in half of the site-years. The type of preceding crops of spring wheat-flax or canola-flax had little influence. Rate and timing of P application had little effect on grain Cd, but increasing P rate tended to decrease grain Zn. No interactive effect was detected among tested factors. Grain Zn was not related to grain Cd, but positively to other nutrients such as Fe, Mn, P, Ca, K, and Mg. Both grain Zn and Fe correlated positively with grain protein content, suggesting protein may represent a sink for micronutrients. The study suggested that the tillage management may have beneficial effects on both grain yield and quality. Phosphorus fertilizer can remain available for subsequent crops and high annual inputs in the crop sequence may decrease crop grain Zn. Understanding the environment is important in determining the impact of agricultural management on agronomic and nutrient traits.

  13. Effects of sewage sludge on the yield of plants in the rotation system of wheat-white head cabbage-tomato

    Directory of Open Access Journals (Sweden)

    Mehmet Arif Özyazıcı

    2013-01-01

    Full Text Available This research was carried to determine the effects of sewage sludge applications on the yield and yield components of plants under crop rotation system. The field experiments were conducted in the Bafra Plain, located in the north region of Turkey. In this research, the “wheat-white head cabbage-tomato” crop rotation systems have been examined and the same crop rotation has been repeated in two separate years and field trials have been established. Seven treatments were compared: a control without application of sludge nor nitrogen fertilization, a treatment without sludge, but nitrogen and phosphorus fertilization, applied at before sowing of wheat and five treatments where, respectively 10, 20, 30, 40 and 50 tons sludge ha-1. The experimental design was a randomized complete block with three replications. The results showed that all the yield components of wheat and yield of white head cabbage and tomato increased significantly with increasing rates of sewage sludge as compared to control. As a result, 20 t ha-1 of sewage sludge application could be recommended the suitable dose for the rotation of wheat-white head cabbage-tomato in soil and climatic conditions of Bafra Plain.

  14. Effects of Continuous Cropping on Soil Microbial Biomas s of Tobacco Field and Quality of Flue-cured Tobacco%烤烟连作土壤微生物数量及烤烟品质变化的比较

    Institute of Scientific and Technical Information of China (English)

    王蒙蒙; 朱金峰; 许自成; 贾健; 王林

    2015-01-01

    The soil microbial quantity and quality of flue-cured tobacco were studied in tobacco field , in which crop rotation , 3-year continuous cropping , and 6-year continuous cropping had been carried out .The results showed that:from resettling stage to vigorous growth stage , further to mature period , the bacterial population in the soil reduced gradually , and it was the highest in the soil of crop rotation .The fungal number in the soil of crop rotation was less than that in the soil of continuous cropping , it reached the maximum at resettling stage in the soil of 6-year continuous cropping , and was significantly higher than that in the soil of crop rotation and 3-year continuous cropping .As for the number of actinomyces in the soil , the following order was found:crop rotation>continuous cropping for 3 years>continuous cropping for 6 years; at resettling stage>at vigorous growth stage>in mature period . There were significant differences in some physical characteristics of flue-cured tobacco ( such as filling value , leaf thickness , ten-sion stress, specific weight of leaf and stem ratio ) between crop rotation and 3-year continuous cropping , but the other indexes had no significant difference .As for the chemical properties of flue-cured tobacco , sugar-nicotine ratio , nitrogen-nicotine ratio , ratio of potassium to chlorine , and Schmuck value showed the sequence of crop rotation >continuous cropping for 6 years>continuous crop-ping for 3 years, they were all in the appropriate range , and their coordination in crop rotation treatment was better than that in con-tinuous cropping treatment .The total amount of neutral aroma components ( excluding neophytadiene ) showed crop rotation >contin-uous cropping for 6 years >continuous cropping for 3 years.%研究了轮作、连作3年、连作6

  15. Economic evaluation of cereal cropping systems under semiarid conditions: minimum input, organic and conventional

    OpenAIRE

    Pardo,Gabriel; Aibar,Joaquín; Cavero,José; Zaragoza,Carlos

    2009-01-01

    Cropping systems like organic farming, selling products at a higher price and promoting environmental sustainability by reducing fertilizer and pesticides, can be more profitable than conventional systems. An economic evaluation of three cropping systems in a seven year period experiment was performed, using a common rotation (fallow-barley-vetch-durum wheat) in a semi-arid rainfed field of Spain. The minimum input system included mouldboard ploughing, cultivator preparation, sowing and harve...

  16. Organic management and cover crop species steer soil microbial community structure and functionality along with soil organic matter properties

    NARCIS (Netherlands)

    Martínez-García, Laura B.; Korthals, Gerard; Brussaard, Lijbert; Jørgensen, Helene Bracht; Deyn, de Gerlinde B.

    2018-01-01

    It is well recognized that organic soil management stimulates bacterial biomass and activity and that including cover crops in the rotation increases soil organic matter (SOM). Yet, to date the relative impact of different cover crop species and organic vs. non-organic soil management on soil

  17. The influence of nitrogen fertiliser rate and crop rotation on soil methane flux in rain-fed potato fields in Wuchuan County, China.

    Science.gov (United States)

    Wang, Liwei; Pan, Zhihua; Xu, Hui; Wang, Cheng; Gao, Lin; Zhao, Peiyi; Dong, Zhiqiang; Zhang, Jingting; Cui, Guohui; Wang, Sen; Han, Guolin; Zhao, Hui

    2015-12-15

    As one of the important greenhouse gases, the characteristics and principles of methane exchange characteristics in cultivated lands have become hot topics in current climate change research. This study examines the influences of nitrogen fertilisation, temperature and soil water content on methane exchange characteristic and methane exchange functional gene-pmoA gene abundance based on experimental observations of methane exchange fluxes using the static chamber-gas chromatographic method and measurements of methanotroph gene copy numbers in three growing periods by real-time PCR in rain-fed potato fields. The results indicate that the rain-fed potato fields were a CH4 sink with an average annual methane absorption (negative emission) of 940.8±103.2 g CH4-C/ha/year. The cumulative methane absorption first exhibited flat and subsequently increasing trend with the increase of nitrogen fertilisation from 0~135 kg N·ha(-1). Methane cumulative absorption significantly increased with the increase of temperature when temperatures were below 19.6 °C. Methane oxidation capacity (methanotroph pmoA gene copy numbers) showed an increasing and subsequently decreasing trend with the increase of soil moisture. Crop rotation was observed to increase the methane absorption in rain-fed potato fields and nearly one time higher than that under continuous cropping. A mechanism concept model of the methane exchange in rain-fed potato fields was advanced in this paper. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Bacterial community variations in an alfalfa-rice rotation system revealed by 16S rRNA gene 454-pyrosequencing.

    Science.gov (United States)

    Lopes, Ana R; Manaia, Célia M; Nunes, Olga C

    2014-03-01

    Crop rotation is a practice harmonized with the sustainable rice production. Nevertheless, the implications of this empirical practice are not well characterized, mainly in relation to the bacterial community composition and structure. In this study, the bacterial communities of two adjacent paddy fields in the 3rd and 4th year of the crop rotation cycle and of a nonseeded subplot were characterized before rice seeding and after harvesting, using 454-pyrosequencing of the 16S rRNA gene. Although the phyla Acidobacteria, Proteobacteria, Chloroflexi, Actinobacteria and Bacteroidetes predominated in all the samples, there were variations in relative abundance of these groups. Samples from the 3rd and 4th years of the crop rotation differed on the higher abundance of groups of presumable aerobic bacteria and of presumable anaerobic and acidobacterial groups, respectively. Members of the phylum Nitrospira were more abundant after rice harvest than in the previously sampled period. Rice cropping was positively correlated with the abundance of members of the orders Acidobacteriales and 'Solibacterales' and negatively with lineages such as Chloroflexi 'Ellin6529'. Studies like this contribute to understand variations occurring in the microbial communities in soils under sustainable rice production, based on real-world data. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  19. The comparison of nitrogen use and leaching in sole cropped versus intercropped pea and barley

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, H.; Ambus, P.; Jensen, E.S.

    2003-01-01

    The effect of sole and intercropping of field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L.) and of crop residue management on crop yield, NO3- leaching and N balance in the cropping system was tested in a 2-year lysimeter experiment on a temperate sandy loam soil. The crop rotation...... cropping. Crops received no fertilizer in the experimental period. Natural N-15 abundance techniques were used to determine pea N-2 fixation. The pea-barley intercrop yielded 4.0 Mg grain ha(-1), which was about 0.5 Mg lower than the yields of sole cropped pea but about 1.5 Mg greater than harvested...... was pea and barley sole and intercrops followed by winter-rye and a fallow period. The Land Equivalent Ratio (LER), which is defined as the relative land area under sole crops that is required to produce the yields achieved in intercropping, was used to compare intercropping performance relative to sole...

  20. Impacts of previous crops on Fusarium foot and root rot, and on yields of durum wheat in North West Tunisia

    Directory of Open Access Journals (Sweden)

    Samia CHEKALI

    2016-07-01

    Full Text Available The impacts of ten previous crop rotations (cereals, legumes and fallow on Fusarium foot and root rot of durum wheat were investigated for three cropping seasons in a trial established in 2004 in Northwest Tunisia. Fungi isolated from the roots and stem bases were identified using morphological and molecular methods, and were primarily Fusarium culmorum and F. pseudograminearum. Under low rainfall conditions, the previous crop affected F. pseudograminearum incidence on durum wheat roots but not F. culmorum. Compared to continuous cropping of durum wheat, barley as a previous crop increased disease incidence more than fivefold, while legumes and fallow tended to reduce incidence.  Barley as a previous crop increased wheat disease severity by 47%, compared to other rotations. Grain yield was negatively correlated with the incidence of F. culmorum infection, both in roots and stem bases, and fitted an exponential model (R2 = -0.61 for roots and -0.77 for stem bases, P<0.0001. Fusarium pseudograminearum was also negatively correlated with yield and fitted an exponential model (R2 = -0.53 on roots and -0.71 on stem bases, P < 0.0001 but was not correlated with severity.

  1. Geo-Parcel Based Crop Identification by Integrating High Spatial-Temporal Resolution Imagery from Multi-Source Satellite Data

    Directory of Open Access Journals (Sweden)

    Yingpin Yang

    2017-12-01

    Full Text Available Geo-parcel based crop identification plays an important role in precision agriculture. It meets the needs of refined farmland management. This study presents an improved identification procedure for geo-parcel based crop identification by combining fine-resolution images and multi-source medium-resolution images. GF-2 images with fine spatial resolution of 0.8 m provided agricultural farming plot boundaries, and GF-1 (16 m and Landsat 8 OLI data were used to transform the geo-parcel based enhanced vegetation index (EVI time-series. In this study, we propose a piecewise EVI time-series smoothing method to fit irregular time profiles, especially for crop rotation situations. Global EVI time-series were divided into several temporal segments, from which phenological metrics could be derived. This method was applied to Lixian, where crop rotation was the common practice of growing different types of crops, in the same plot, in sequenced seasons. After collection of phenological features and multi-temporal spectral information, Random Forest (RF was performed to classify crop types, and the overall accuracy was 93.27%. Moreover, an analysis of feature significance showed that phenological features were of greater importance for distinguishing agricultural land cover compared to temporal spectral information. The identification results indicated that the integration of high spatial-temporal resolution imagery is promising for geo-parcel based crop identification and that the newly proposed smoothing method is effective.

  2. Nitrogen leaching: A crop rotation perspective on the effect of N surplus, field management and use of catch crops

    DEFF Research Database (Denmark)

    De Notaris, Chiara; Rasmussen, Jim; Sørensen, Peter

    2018-01-01

    Components of the field nitrogen (N) balance (input and surplus) are often used to predict nitrate leaching from agricultural lands. However, management factors, such as use of catch crops, greatly affect the actual loss and are a key to reduce N leaching. The present study is based on the 4th cy...

  3. Factors affecting the income from major crops in rice-wheat ecological zone

    International Nuclear Information System (INIS)

    Ashfaq, M.; Naseer, M.Z.; Hassan, S.

    2008-01-01

    Agriculture is an important sector of our economy. About twenty-two percent of national income and 44.8 percent of total employment is generated by this sector. About 66 percent of country's population is living in rural areas and is directly or indirectly linked with agriculture for their livelihood. It also supplies raw materials to industry. The rice-wheat zone of Punjab covers 1.1 million hectare, 72% of wheat is grown in rotation with rice. The main purpose of this paper was to determine the effect of different factors on the productivity and ultimately on income from of major crops (wheat, rice and sugar-cane) in rice-wheat ecological zone. The results show that for wheat crop, land preparation, use of fertilizer and chemicals, for Sugarcane crop, area under cultivation, fertilizer and chemical costs and for rice crop, applications of chemicals, irrigation and land holding were the main determinants of productivity and crop income. (author)

  4. Enhanced yields and soil quality in a wheat-maize rotation using buried straw mulch.

    Science.gov (United States)

    Guo, Zhibin; Liu, Hui; Wan, Shuixia; Hua, Keke; Jiang, Chaoqiang; Wang, Daozhong; He, Chuanlong; Guo, Xisheng

    2017-08-01

    Straw return may improve soil quality and crop yields. In a 2-year field study, a straw return method (ditch-buried straw return, DB-SR) was used to investigate the soil quality and crop productivity effects on a wheat-corn rotation system. This study consisted of three treatments, each with three replicates: (1) mineral fertilisation alone (CK0); (2) mineral fertilisation + 7500 kg ha -1 wheat straw incorporated at depth of 0-15 cm (NPKWS); and (3) mineral fertilisation + 7500 kg ha -1 wheat straw ditch buried at 15-30 cm (NPKDW). NPKWS and NPKDW enhanced crop yield and improved soil biotical properties compared to mineral fertilisation alone. NPKDW contributed to greater crop yields and soil nutrient availability at 15-30 cm depths, compared to NPKWS treatment. NPKDW enhanced soil microbial activity and bacteria species richness and diversity in the 0-15 cm layer. NPKWS increased soil microbial biomass, bacteria species richness and diversity at 15-30 cm. The comparison of the CK0 and NPKWS treatments indicates that a straw ditch buried by digging to the depth of 15-30 cm can improve crop yields and soil quality in a wheat-maize rotation system. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  5. Introducing perennial biomass crops into agricultural landscapes to address water quality challenges and provide other environmental services: Integrating perennial bioenergy crops into agricultural landscapes

    Energy Technology Data Exchange (ETDEWEB)

    Cacho, J. F. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA; Negri, M. C. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA; Zumpf, C. R. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA; Campbell, P. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA

    2017-11-29

    The world is faced with a difficult multiple challenge of meeting nutritional, energy, and other basic needs, under a limited land and water budget, of between 9 and 10 billion people in the next three decades, mitigating impacts of climate change, and making agricultural production resilient. More productivity is expected from agricultural lands, but intensification of production could further impact the integrity of our finite surface water and groundwater resources. Integrating perennial bioenergy crops in agricultural lands could provide biomass for biofuel and potential improvements on the sustainability of commodity crop production. This article provides an overview of ways in which research has shown that perennial bioenergy grasses and short rotation woody crops can be incorporated into agricultural production systems with reduced indirect land use change, while increasing water quality benefits. Current challenges and opportunities as well as future directions are also highlighted.

  6. Estimating effectiveness of crop management for reduction of soil erosion and runoff

    Science.gov (United States)

    Hlavcova, K.; Studvova, Z.; Kohnova, S.; Szolgay, J.

    2017-10-01

    The paper focuses on erosion processes in the Svacenický Creek catchment which is a small sub-catchment of the Myjava River basin. To simulate soil loss and sediment transport the USLE/SDR and WaTEM/SEDEM models were applied. The models were validated by comparing the simulated results with the actual bathymetry of a polder at the catchment outlet. Methods of crop management based on rotation and strip cropping were applied for the reduction of soil loss and sediment transport. The comparison shows that the greatest intensities of soil loss were achieved by the bare soil without vegetation and from the planting of maize for corn. The lowest values were achieved from the planting of winter wheat. At the end the effectiveness of row crops and strip cropping for decreasing design floods from the catchment was estimated.

  7. Cover crops effect on farm benefits and nitrate leaching: linking economic and environmental analysis

    Science.gov (United States)

    Gabriel, José Luis; Vanclooster, Marnik; Garrido, Alberto; Quemada, Miguel

    2013-04-01

    Introducing cover crops interspersed with intensively fertilized crops in rotation has the potential to reduce nitrate leaching. However, despite the evident environmental services provided and the range of agronomic benefits documented in the literature, farmers' adoption of the technique is still limited because growing CC could lead to extra costs for the farm in three different forms: direct, indirect, and opportunity costs. Environmental studies are complex, and evaluating the indicators that are representative of the environmental impact of an agricultural system is a complicated task that is conducted by specialized groups and methodologies. Multidisciplinary studies may help to develop reliable approaches that would contribute to choosing the best agricultural strategies based on linking economic and environmental benefits. This study evaluates barley (Hordeum vulgare L., cv. Vanessa), vetch (Vicia villosa L., cv. Vereda) and rapeseed (Brassica napus L., cv. Licapo) as cover crops between maize, leaving the residue in the ground or selling it for animal feeding, and compares the economic and environmental results with respect to a typical maize-fallow rotation. Nitrate leaching for different weather conditions was calculated using the mechanistic-deterministic WAVE model, using the Richards equation parameterised with a conceptual model for the soil hydraulic properties for describing the water flow in the vadose zone, combined with field observed data. The economic impact was evaluated through stochastic (Monte-Carlo) simulation models of farms' profits using probability distribution functions of maize yield and cover crop biomass developed fitted with data collected from various field trials (during more than 5 years) and probability distribution functions of maize and different cover crop forage prices fitted from statistical sources. Stochastic dominance relationships are obtained to rank the most profitable strategies from a farm financial perspective

  8. Impacts of Cropping Systems on Aggregates Associated Organic Carbon and Nitrogen in a Semiarid Highland Agroecosystem.

    Directory of Open Access Journals (Sweden)

    Jiashu Chu

    Full Text Available The effect of cropping system on the distribution of organic carbon (OC and nitrogen (N in soil aggregates has not been well addressed, which is important for understanding the sequestration of OC and N in agricultural soils. We analyzed the distribution of OC and N associated with soil aggregates in three unfertilized cropping systems in a 27-year field experiment: continuously cropped alfalfa, continuously cropped wheat and a legume-grain rotation. The objectives were to understand the effect of cropping system on the distribution of OC and N in aggregates and to examine the relationships between the changes in OC and N stocks in total soils and in aggregates. The cropping systems increased the stocks of OC and N in total soils (0-40 cm at mean rates of 15.6 g OC m-2 yr-1 and 1.2 g N m-2 yr-1 relative to a fallow control. The continuous cropping of alfalfa produced the largest increases at the 0-20 cm depth. The OC and N stocks in total soils were significantly correlated with the changes in the >0.053 mm aggregates. 27-year of cropping increased OC stocks in the >0.053 mm size class of aggregates and N stocks in the >0.25 mm size class but decreased OC stocks in the 0.25 mm aggregate size class accounted for more than 97% of the total increases in the continuous wheat and the legume-grain rotation systems. These results suggested that long-term cropping has the potential to sequester OC and N in soils and that the increases in soil OC and N stocks were mainly due to increases associated with aggregates >0.053 mm.

  9. Cultivar specific plant-soil feedback overrules soil legacy effects of elevated ozone in a rice-wheat rotation system

    NARCIS (Netherlands)

    Li, Qi; Yang, Yue; Bao, Xuelian; Zhu, Jianguo; Liang, Wenju; Bezemer, T. Martijn

    2016-01-01

    Abstract Tropospheric ozone has been recognized as one of the most important air pollutants. Many studies have shown that elevated ozone negatively impacts yields of important crops such as wheat or rice, but how ozone influences soil ecosystems of these crops and plant growth in rotation systems is

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

    Directory of Open Access Journals (Sweden)

    Salvatore L. Cosentino

    2008-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Giuseppina M. D’Agosta

    2011-02-01

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

  12. Barriers to implementing climate resilient agricultural strategies: The case of crop diversification in the U.S. Corn Belt

    Science.gov (United States)

    Gabrielle E. Roesch-McNally; J.G. Arbuckle; John C. Tyndall

    2018-01-01

    Cropping system diversity can help build greater agroecosystem resilience by suppressing insect, weed, and disease pressures while also mitigating effects of extreme and more variable weather. Despite the potential benefits of cropping systems diversity, few farmers in the US Corn Belt use diverse rotations. This study examines factors that may influence farmers’...

  13. Theoretical prediction of a rotating magnon wave packet in ferromagnets.

    Science.gov (United States)

    Matsumoto, Ryo; Murakami, Shuichi

    2011-05-13

    We theoretically show that the magnon wave packet has a rotational motion in two ways: a self-rotation and a motion along the boundary of the sample (edge current). They are similar to the cyclotron motion of electrons, but unlike electrons the magnons have no charge and the rotation is not due to the Lorentz force. These rotational motions are caused by the Berry phase in momentum space from the magnon band structure. Furthermore, the rotational motion of the magnon gives an additional correction term to the magnon Hall effect. We also discuss the Berry curvature effect in the classical limit of long-wavelength magnetostatic spin waves having macroscopic coherence length.

  14. Measurement of plasma conductivity using faraday rotation of submillimeter waves

    International Nuclear Information System (INIS)

    Kuzmenko, P.J.; Self, S.A.

    1983-01-01

    This paper examines the application of Faraday rotation to the measurement of electron combustion MHD plasmas. Details on the design of a working system are given, including the selection of operating wavelength. A theoretical comparison between the Faraday rotation technique and two-path interferometry shows Faraday rotation in its simplest form to be somewhat less sensitive to changes in electron concentration. This deficit can be balanced against greater immunity to vibration and thermal drift. Improved techniques of measuring the rotation angle promise greater sensitivity. A preliminary experiment has verified the technique

  15. Oblique electron-cyclotron-emission radial and phase detector of rotating magnetic islands applied to alignment and modulation of electron-cyclotron-current-drive for neoclassical tearing mode stabilization

    International Nuclear Information System (INIS)

    Volpe, F.; Austin, M. E.; Campbell, G.; Deterly, T.

    2012-01-01

    A two channel oblique electron cyclotron emission (ECE) radiometer was installed on the DIII-D tokamak and interfaced to four gyrotrons. Oblique ECE was used to toroidally and radially localize rotating magnetic islands and so assist their electron cyclotron current drive (ECCD) stabilization. In particular, after manipulations operated by the interfacing analogue circuit, the oblique ECE signals directly modulated the current drive in synch with the island rotation and in phase with the island O-point, for a more efficient stabilization. Apart from the different toroidal location, the diagnostic view is identical to the ECCD launch direction, which greatly simplified the real-time use of the signals. In fact, a simple toroidal extrapolation was sufficient to lock the modulation to the O-point phase. This was accomplished by a specially designed phase shifter of nearly flat response over the 1–7 kHz range. Moreover, correlation analysis of two channels slightly above and below the ECCD frequency allowed checking the radial alignment to the island, based on the fact that for satisfactory alignment the two signals are out of phase.

  16. Oviposition Behaviors in Relation to Rotation Resistance in the Western Corn Rootworm

    NARCIS (Netherlands)

    Knolhoff, L.M.; Glas, J.J.; Spencer, J.L.; Berenbaum, M.R.

    2010-01-01

    Across a large area of the midwestern United States Corn Belt, the western corn rootworm beetle (Diabrotica virgifera virgifera LeConte, Coleoptera: Chrysomelidae) exhibits behavioral resistance to annual crop rotation. Resistant females exhibit increased locomotor activity and frequently lay eggs

  17. Fate of Clavibacter michiganensis ssp. sepedonicus, the causal organism of bacterial ring rot in potato, in weeds and field crops.

    NARCIS (Netherlands)

    Wolf, van der J.M.; Beckhoven, van J.R.C.M.; Hukkanen, A.; Karjalainen, R.; Muller, P.

    2005-01-01

    Crops and weeds were tested for their ability to host Clavibacter michiganensis ssp. sepedonicus (Cms), the causal agent of bacterial ring rot in potato. Ten crops grown in rotation with potato in Europe, namely maize, wheat, barley, oat, bush bean, broad bean, rape, pea and onion and five cultivars

  18. Rotational distributions of molecular photoions following resonant excitation

    International Nuclear Information System (INIS)

    Poliakoff, E.D.; Chan, J.C.K.; White, M.G.

    1986-01-01

    We demonstrate that the photoelectron energy mediates the rotational energy distribution of N + 2 ions created by photoionization, and conversely, that rotational energy determinations probe resonant excitation in molecular photoionization. Experimentally, this is accomplished by monitoring the dispersed fluorescence from N + 2 (B 2 Σ + /sub u/) photoions to determine their rotational energy distribution. These results demonstrate that while dipole selection rules constrain the total angular momentum of the electron--ion complex, the partitioning of angular momentum between the photoelectron and photoion depends on the photoejection dynamics. Implications for photoionization and electron impact ionizatin studies are discussed

  19. Water requirements of short rotation poplar coppice: Experimental and modelling analyses across Europe

    Czech Academy of Sciences Publication Activity Database

    Fischer, Milan; Zenone, T.; Trnka, Miroslav; Orság, Matěj; Montagnani, L.; Ward, E. J.; Tripathi, Abishek; Hlavinka, Petr; Seufert, G.; Žalud, Zdeněk; King, J.; Ceulemans, R.

    2018-01-01

    Roč. 250, MAR (2018), s. 343-360 ISSN 0168-1923 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : energy-balance closure * dual crop coefficient * radiation use efficiency * simulate yield response * below-ground carbon * vs. 2nd rotation * flux data * biomass production * forest model * stand-scale * Bioenergy * Bowen ratio and energy balance * Crop coefficient * Eddy covariance * Evapotranspiration * Water balance Subject RIV: GC - Agronomy OBOR OECD: Agriculture Impact factor: 3.887, year: 2016

  20. Electron scattering by CO2: Elastic scattering, rotational excitation, and excitation of the asymmetric stretch at 10 eV impact energy

    International Nuclear Information System (INIS)

    Thirumalai, D.; Onda, K.; Truhlar, D.G.

    1981-01-01

    Coupled-channels calculations based on an effective potential are presented for electron scattering by CO 2 at 10 eV impact energy. The processes studied are pure elastic scattering, rotational excitation, and vibrational excitation of the asymmetric stretch; the vibrational excitation is always accompanied by rotational excitation. The quantities calculated are differential, partial, integral, and momentum transfer cross sections, both state to state and summed over final rotational states for a given final vibrational level. The effective potential is based on the INDOX2/1s method for the static and polarization potentials and the semiclassical exchange approximation for the exchange potential. There are no empirical parameters. The present calculations are compared to experiment and to previous calculations where available, and we also perform calculations with an altered polarization potential to further elucidate the reasons for the differences from one of the previous calculations. The agreement of the present results with the experimental rotationally summed, vibrationally inelastic differential cross section is excellent

  1. Rotating structures in low temperature magnetized plasmas - Insight from particle simulations

    Directory of Open Access Journals (Sweden)

    Jean-Pierre eBoeuf

    2014-12-01

    Full Text Available The EXB configuration of various low temperature plasma devices is often responsible for the formation of rotating structures and instabilities leading to anomalous electron transport across the magnetic field. In these devices, electrons are strongly magnetized while ions are weakly or not magnetized and this leads to specific physical phenomena that are not present in fusion plasmas where both electrons and ions are strongly magnetized. In this paper we describe basic phenomena involving rotating plasma structures in simple configurations of low temperature EXB plasma devices on the basis of PIC-MCC (Particle-In-Cell Monte Carlo Collisions simulations. We focus on three examples: rotating electron vortices and rotating spokes in cylindrical magnetrons, and azimuthal electron-cyclotron drift instability in Hall thrusters. The simulations are not intended to give definite answers to the many physics issues related to low temperature EXB plasma devices but are used to illustrate and discuss some of the basic questions that need further studies.

  2. The Potential Research of Catch Crop in Decrease Soil Nitrate Under Greenhouse Vegetable Production

    Directory of Open Access Journals (Sweden)

    YIN Xing

    2015-06-01

    Full Text Available In order to clarify the impact of catch crops on greenhouse vegetable soil nitrate, explore the mechanism of barrier and controll soil nitrogen leaching losses in greenhouse, and provide a theoretical basis for control nitrogen leaching and prevention of groundwater pollution, this study selected the traditional greenhouse vegetable rotation system in North China plain as research subjects, using field situ remediation technologies on deep-root planting catch crops in the vegetable fallow period by sweet corn, Achyranthes bidentata and white Chrysanthemum. The results showed that: nitrogen content and nitrogen uptake of sweet corn and sweet corn with Achyranthes bidentata intercropping were the highest, respectively 20.11 t·hm-2, 19.62 t·hm-2 and 240.34 kg·hm-2, 287.56 kg·hm-2, significantly higher than white Chrysanthemum. The density of root length and root dry weight decreased with soil depth in the profiles, root length density was demonstrated in order as: intercropping sweet corn> sweet corn> white Chrysanthemum> intercropping Achyranthes bidentata blume. The reduction of NO3--N of sweet corn reached 907.87 kg·hm-2 in soil profile 0~200 cm, significantly higher than sweet corn and hyssop intercropping and white Chrysanthemums. In the interim period of vegetable crop rotation, planting catch crops could effectively reduce nitrate accumulation in the soil, control the soil profile nitrate leaching down.

  3. Crop Nitrogen Uptake in A Legume-wheat Rotation Using1'5N Methodology

    International Nuclear Information System (INIS)

    Badarneh, D.

    2005-01-01

    Afield experiment was conducted to assess the impact of residual N from legume crops, fertilizer applied N, and fallow on the subsequent wheat production. The experiment was carried out in a randomized complex block design for the years 1993 and 1994. In 1993, barley was planted as a reference crop in legume plots. Micro plots, in both years were treated with 15 N. In 1994, whole plots were planted with wheat. In 1993, the yield of lentil treatments was not significantly different. The wheat yield, responded significantly to N addition. Lentil and chickpea derived 2/3 and 3/4 of their N needs from the atmosphere, respectively. In contrast, wheat derived most of its N needs(90%) from the soil. Water consumption was similar expect for wheat fertilized at low rate of N (179.5 mm). In 1994, wheat yields, the harvesting index and water consumption were not significantly different. Traditional harvesting of lentil and fertilizing wheat at a low rate reduced significantly the N% of wheat bio-mass. The % of N derived from fertilizer (Ndff) by wheat was much higher in 1994 (4.18 to 9.24%), but it was 3.62% for the fallow treatments. The % of N derived from soil (%Ndfs) by wheat 93% in 1994 for wheat planted after legume. The results indicated that legumes depleted soil N under the croping system currently adopted in Jordan, and the benefit of fallow to the subsequent wheat crop is attributed to the increase of soil organic N mineralization. (Author) 35 refs., 3 tabs., 2 figs

  4. Long-term conventional and no-tillage effects on field hydrology and yields of a dryland crop rotation

    Science.gov (United States)

    Semiarid dryland crop yields with no-till, NT, residue management are often greater than stubble-mulch, SM, tillage as a result of improved soil conditions and water conservation, but information on long-term tillage effects on field hydrology and sustained crop production are needed. Our objective ...

  5. Toward cropping systems that enhance productivity and sustainability

    Science.gov (United States)

    Cook, R. James

    2006-01-01

    The defining features of any cropping system are (i) the crop rotation and (ii) the kind or intensity of tillage. The trend worldwide starting in the late 20th century has been (i) to specialize competitively in the production of two, three, a single, or closely related crops such as different market classes of wheat and barley, and (ii) to use direct seeding, also known as no-till, to cut costs and save soil, time, and fuel. The availability of glyphosate- and insect-resistant varieties of soybeans, corn, cotton, and canola has helped greatly to address weed and insect pest pressures favored by direct seeding these crops. However, little has been done through genetics and breeding to address diseases caused by residue- and soil-inhabiting pathogens that remain major obstacles to wider adoption of these potentially more productive and sustainable systems. Instead, the gains have been due largely to innovations in management, including enhancement of root defense by antibiotic-producing rhizosphere-inhabiting bacteria inhibitory to root pathogens. Historically, new varieties have facilitated wider adoption of new management, and changes in management have facilitated wider adoption of new varieties. Although actual yields may be lower in direct-seed compared with conventional cropping systems, largely due to diseases, the yield potential is higher because of more available water and increases in soil organic matter. Achieving the full production potential of these more-sustainable cropping systems must now await the development of varieties adapted to or resistant to the hazards shown to account for the yield depressions associated with direct seeding. PMID:17130454

  6. Cultivation of minor tuber crops in Peru and Bolivia

    Directory of Open Access Journals (Sweden)

    Leena Pietilä

    1988-03-01

    Full Text Available A collection mission of three Andean tuber crops, oca (Oxalis tuberosa, Oxalidaceae, ulluco (Ullucus tuberosus, Basellaceae and añu (Tropaeolum tuberosum, Tropaeolaceae, was carried out in southern Peru, Bolivia and northern Argentina. This article deals with the observations made during this mission. 55 ulluco fields were visited. In general, the fields are small, 240m2 on average, and they are mostly situated on mountain slopes. The fields are fertilized with animal dung; chemical fertilizers are quite rare. In the fields, people work with hoes ang ploughs as they did hundreds of years ago. Mechanization of agriculture would prevent full utilization of the mountainous area of the Andes. Ulluco is usually interplanted with other crops, usually, many forms of ulluco in one field. Because of crop rotation description of the fields is partly valid for the cultivation of other crops, too. Due to drastic climatic variation, cultivation of mixed varieties maybe the best way to guarantee some yield. When results of the investigations are wished to benefit developing countries, knowledge of social, agricultural and environmental factors is of great value.

  7. The Potential for Cereal Rye Cover Crops to Host Corn Seedling Pathogens.

    Science.gov (United States)

    Bakker, Matthew G; Acharya, Jyotsna; Moorman, Thomas B; Robertson, Alison E; Kaspar, Thomas C

    2016-06-01

    Cover cropping is a prevalent conservation practice that offers substantial benefits to soil and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects because two grass species are grown in succession. Here, we show that rye cover crops host pathogens capable of causing corn seedling disease. We isolated Fusarium graminearum, F. oxysporum, Pythium sylvaticum, and P. torulosum from roots of rye and demonstrate their pathogenicity on corn seedlings. Over 2 years, we quantified the densities of these organisms in rye roots from several field experiments and at various intervals of time after rye cover crops were terminated. Pathogen load in rye roots differed among fields and among years for particular fields. Each of the four pathogen species increased in density over time on roots of herbicide-terminated rye in at least one field site, suggesting the broad potential for rye cover crops to elevate corn seedling pathogen densities. The radicles of corn seedlings planted following a rye cover crop had higher pathogen densities compared with seedlings following a winter fallow. Management practices that limit seedling disease may be required to allow corn yields to respond positively to improvements in soil quality brought about by cover cropping.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    and ending the strategy with mouldboard ploughing in the succeeding spring. Grain yields did not differ among the treatments in the two experiments as a result of the generally high effectiveness exerted by the control strategies. Especially post-harvest control strategies based on rotating weed devices...... and mouldboard ploughing appear to be effective solutions against mixed stands of perennials on sandy soils but they do not comply with optimal nutrient management in organic cropping. Therefore, intensive autumn cultivation is only relevant where a perennial weed problem is uncontrollable by other means.......Perennial weeds can be a major constraint to organic crop production and direct control actions applied between crops can then be necessary to reduce the problems. We conducted two experiments, one on a sandy loam and one on a sandy soil in Denmark, with the aim of studying the efficacy...

  9. Soil water regime and crop yields in relation to various technologies of cultivation in the Kulunda Steppe (Altai Krai

    Directory of Open Access Journals (Sweden)

    V. Beliaev

    2016-09-01

    Full Text Available This article presents the results of crop yield in areas with different technologies of cultivation based on the network of automatic stations that provide data on climatic and soil-hydrological monitoring in the dry steppe during the vegetation period of May–September 2013–2016 . These data  on regional ecological and climatic parameters are of great interest to the ecologists, plant physiologists, and farmers working in the Kulunda Plain (Altai Territory. We compared the following options for cropping technologies: the modern system, which is the "no-till", technology without autumn tillage;the intensive technology of deep autumn tillage by plough PG-3-5 at a depth of 22–24 cm. Cultivation of crops was carried out using the following scheme of crop rotation: the modern system: 1–2–3–4 (wheat – peas – wheat – rape; the intensive system: 5/6 – 7/8 – 9/10 (fallow – wheat – wheat. We believe that the use of modern technology in these conditions is better due to exchange between the different layers of soil. When  the ordinary Soviet system , the so-called "plow sole" , was used , at a depth of 24 cm , we observed that this creates a water conductivity barrier that seems to preclude the possibility of lifting water from the lower horizons. Results of the study of infiltration of soil moisture at the depth of 30 and 60 cm  have shown in some years the advantages of the modern technology over the ordinary Soviet system: in the version with the use of modern technology we can trace better exchange between the various horizons and , probably,  moisture replenishment from the lower horizons. Differences in individual observation periods are comparatively large due to the redistribution of soil moisture, depending on the weather conditions, the crops used in the crop rotations, and cultivation techniques. Moreover, the average moisture reserves within the one meter layer did not show any significant differences during the

  10. Three-dimensional rotation electron diffraction: software RED for automated data collection and data processing.

    Science.gov (United States)

    Wan, Wei; Sun, Junliang; Su, Jie; Hovmöller, Sven; Zou, Xiaodong

    2013-12-01

    Implementation of a computer program package for automated collection and processing of rotation electron diffraction (RED) data is described. The software package contains two computer programs: RED data collection and RED data processing. The RED data collection program controls the transmission electron microscope and the camera. Electron beam tilts at a fine step (0.05-0.20°) are combined with goniometer tilts at a coarse step (2.0-3.0°) around a common tilt axis, which allows a fine relative tilt to be achieved between the electron beam and the crystal in a large tilt range. An electron diffraction (ED) frame is collected at each combination of beam tilt and goniometer tilt. The RED data processing program processes three-dimensional ED data generated by the RED data collection program or by other approaches. It includes shift correction of the ED frames, peak hunting for diffraction spots in individual ED frames and identification of these diffraction spots as reflections in three dimensions. Unit-cell parameters are determined from the positions of reflections in three-dimensional reciprocal space. All reflections are indexed, and finally a list with hkl indices and intensities is output. The data processing program also includes a visualizer to view and analyse three-dimensional reciprocal lattices reconstructed from the ED frames. Details of the implementation are described. Data collection and data processing with the software RED are demonstrated using a calcined zeolite sample, silicalite-1. The structure of the calcined silicalite-1, with 72 unique atoms, could be solved from the RED data by routine direct methods.

  11. Integrating soil conservation practices and glyphosate-resistant crops: impacts on soil.

    Science.gov (United States)

    Locke, Martin A; Zablotowicz, Robert M; Reddy, Krishna N

    2008-04-01

    Conservation practices often associated with glyphosate-resistant crops, e.g. limited tillage and crop cover, improve soil conditions, but only limited research has evaluated their effects on soil in combination with glyphosate-resistant crops. It is assumed that conservation practices have similar benefits to soil whether or not glyphosate-resistant crops are used. This paper reviews the impact on soil of conservation practices and glyphosate-resistant crops, and presents data from a Mississippi field trial comparing glyphosate-resistant and non-glyphosate-resistant maize (Zea mays L.) and cotton (Gossypium hirsutum L.) under limited tillage management. Results from the reduced-tillage study indicate differences in soil biological and chemical properties owing to glyphosate-resistant crops. Under continuous glyphosate-resistant maize, soils maintained greater soil organic carbon and nitrogen as compared with continuous non-glyphosate-resistant maize, but no differences were measured in continuous cotton or in cotton rotated with maize. Soil microbial community structure based on total fatty acid methyl ester analysis indicated a significant effect of glyphosate-resistant crop following 5 years of continuous glyphosate-resistant crop as compared with the non-glyphosate-resistant crop system. Results from this study, as well as the literature review, indicate differences attributable to the interaction of conservation practices and glyphosate-resistant crop, but many are transient and benign for the soil ecosystem. Glyphosate use may result in minor effects on soil biological/chemical properties. However, enhanced organic carbon and plant residues in surface soils under conservation practices may buffer potential effects of glyphosate. Long-term field research established under various cropping systems and ecological regions is needed for critical assessment of glyphosate-resistant crop and conservation practice interactions. Copyright (c) 2008 by John Wiley & Sons

  12. Crop Condition Assessment with Adjusted NDVI Using the Uncropped Arable Land Ratio

    Directory of Open Access Journals (Sweden)

    Miao Zhang

    2014-06-01

    Full Text Available Crop condition assessment in the early growing stage is essential for crop monitoring and crop yield prediction. A normalized difference vegetation index (NDVI-based method is employed to evaluate crop condition by inter-annual comparisons of both spatial variability (using NDVI images and seasonal dynamics (based on crop condition profiles. Since this type of method will generate false information if there are changes in crop rotation, cropping area or crop phenology, information on cropped/uncropped arable land is integrated to improve the accuracy of crop condition monitoring. The study proposes a new method to retrieve adjusted NDVI for cropped arable land during the growing season of winter crops by integrating 16-day composite Moderate Resolution Imaging Spectroradiometer (MODIS reflectance data at 250-m resolution with a cropped and uncropped arable land map derived from the multi-temporal China Environmental Satellite (Huan Jing Satellite charge-coupled device (HJ-1 CCD images at 30-m resolution. Using the land map’s data on cropped and uncropped arable land, a pixel-based uncropped arable land ratio (UALR at 250-m resolution was generated. Next, the UALR-adjusted NDVI was produced by assuming that the MODIS reflectance value for each pixel is a linear mixed signal composed of the proportional reflectance of cropped and uncropped arable land. When UALR-adjusted NDVI data are used for crop condition assessment, results are expected to be more accurate, because: (i pixels with only uncropped arable land are not included in the assessment; and (ii the adjusted NDVI corrects for interannual variation in cropping area. On the provincial level, crop growing profiles based on the two kinds of NDVI data illustrate the difference between the regular and the adjusted NDVI, with the difference depending on the total area of uncropped arable land in the region. The results suggested that the proposed method can be used to improve the assessment of

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

    Science.gov (United States)

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

    2012-12-01

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

  14. Controlling electron quantum paths for generation of circularly polarized high-order harmonics by H2+ subject to tailored (ω , 2 ω ) counter-rotating laser fields

    Science.gov (United States)

    Heslar, John; Telnov, Dmitry A.; Chu, Shih-I.

    2018-04-01

    Recently, studies of high-order harmonics (HHG) from atoms driven by bichromatic counter-rotating circularly polarized laser fields as a source of coherent circularly polarized extreme ultraviolet (XUV) and soft-x-ray beams in a tabletop-scale setup have received considerable attention. Here, we demonstrate the ability to control the electron recollisions giving three returns per one cycle of the fundamental frequency ω by using tailored bichromatic (ω , 2 ω ) counter-rotating circularly polarized laser fields with a molecular target. The full control of the electronic pathway is first analyzed by a classical trajectory analysis and then extended to a detailed quantum study of H2+ molecules in bichromatic (ω , 2 ω ) counter-rotating circularly polarized laser fields. The radiation spectrum contains doublets of left- and right-circularly polarized harmonics in the XUV ranges. We study in detail the below-, near-, and above-threshold harmonic regions and describe how excited-state resonances alter the ellipticity and phase of the generated harmonic peaks.

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

    International Nuclear Information System (INIS)

    Sherrington, Chris; Moran, Dominic

    2010-01-01

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

  16. Introducing non-flooded crops in rice-dominated landscapes: Impact on carbon, nitrogen and water budgets

    Science.gov (United States)

    Jauker, Frank; Wassmann, Reiner; Amelung, Wulf; Breuer, Lutz; Butterbach-Bahl, Klaus; Conrad, Ralf; Ekschmitt, Klemens; Goldbach, Heiner; He, Yao; John, Katharina; Kiese, Ralf; Kraus, David; Reinhold-Hurek, Barbara; Siemens, Jan; Weller, Sebastian; Wolters, Volkmar

    2013-04-01

    , N2O and CO2 from rice-rice and rice-maize rotations. The conversion of flooded to non-flooded cropping systems resulted in pollution swapping of greenhouse gas emissions, shifting from CH4 under wet conditions to N2O under dry conditions. - Quantification and assessment of water budgets and nutrient loss in rice-rice and rice-maize rotations. Switching from rice-rice dominated growing systems to upland rice or maize-rice cropping systems resulted in reduced water use efficiency and increased nitrogen loss. - Quantification and assessment of soil functions affected by soil fauna community structure in flooded and non-flooded cropping rotations. In contrast to temperate soils, earthworms reduced the peaks of microbial C and N decomposition depending on soil water content.

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

    International Nuclear Information System (INIS)

    Dieckow, Jeferson; Pergher, Maico; Moraes, Anibal de; Piva, Jonatas Thiago; Bayer, Cimélio; Sakadevan, Karuppan

    2015-01-01

    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 (N 2 O) and methane (CH 4 )

  18. Influence of Maize Rotations on the Yield of Soybean Grown in Meloidogyne incognita Infested Soil

    OpenAIRE

    Kinloch, Robert A.

    1983-01-01

    A replicated field study was conducted from 1972 to 1980 involving soybeans grown in 2-, 3-, and 4-year rotations with maize in soil infested with Meloidogyne incognita. Monocultured soybeans were maintained as controls. Cropping regimes involved root-knot nematode susceptible and resistant soybean cultivars and soybeans treated and not treated with nematicides. Yields of susceptible cultivars declined with reduced length of rotation. Nematicide treatment significantly increased yields of sus...

  19. Main-ion temperature and plasma rotation measurements based on scattering of electron cyclotron heating waves in ASDEX Upgrade

    DEFF Research Database (Denmark)

    Pedersen, Morten Stejner; Rasmussen, Jesper; Nielsen, Stefan Kragh

    2017-01-01

    We demonstrate measurements of spectra of O-mode electron cyclotron resonance heating (ECRH) waves scattered collectively from microscopic plasma fluctuations in ASDEX Upgrade discharges with an ITER-like ECRH scenario. The measured spectra are shown to allow determination of the main ion...... temperature and plasma rotation velocity. This demonstrates that ECRH systems can be exploited for diagnostic purposes alongside their primary heating purpose in a reactor relevant scenario....

  20. Leaf photosynthesis and respiration of three bioenergy crops in relation to temperature and leaf nitrogen: how conserved are biochemical model parameters among crop species?

    Science.gov (United States)

    Archontoulis, S. V.; Yin, X.; Vos, J.; Danalatos, N. G.; Struik, P. C.

    2012-01-01

    Given the need for parallel increases in food and energy production from crops in the context of global change, crop simulation models and data sets to feed these models with photosynthesis and respiration parameters are increasingly important. This study provides information on photosynthesis and respiration for three energy crops (sunflower, kenaf, and cynara), reviews relevant information for five other crops (wheat, barley, cotton, tobacco, and grape), and assesses how conserved photosynthesis parameters are among crops. Using large data sets and optimization techniques, the C3 leaf photosynthesis model of Farquhar, von Caemmerer, and Berry (FvCB) and an empirical night respiration model for tested energy crops accounting for effects of temperature and leaf nitrogen were parameterized. Instead of the common approach of using information on net photosynthesis response to CO2 at the stomatal cavity (An–Ci), the model was parameterized by analysing the photosynthesis response to incident light intensity (An–Iinc). Convincing evidence is provided that the maximum Rubisco carboxylation rate or the maximum electron transport rate was very similar whether derived from An–Ci or from An–Iinc data sets. Parameters characterizing Rubisco limitation, electron transport limitation, the degree to which light inhibits leaf respiration, night respiration, and the minimum leaf nitrogen required for photosynthesis were then determined. Model predictions were validated against independent sets. Only a few FvCB parameters were conserved among crop species, thus species-specific FvCB model parameters are needed for crop modelling. Therefore, information from readily available but underexplored An–Iinc data should be re-analysed, thereby expanding the potential of combining classical photosynthetic data and the biochemical model. PMID:22021569

  1. Organic amendment of crop soil and its relation to hotspots of bacterial nitrogen cycling

    Science.gov (United States)

    Pereg, Lily; McMillan, Mary

    2015-04-01

    Crop production in Australian soils requires a high use of fertilisers, including N, P and K for continues utilisation of the soil. Growers often grow crops in rotation of summer crop, such as cotton with winter crop, such as wheat in the same field. Growers are getting more and more aware about sustainability of the soil resources and the more adventurous ones use soil amendments, such as organic supplements in addition to the chemical fertilisers. We have collected soil samples from fields that were cultivated in preparation for planting cotton and tested the soil for its bacterial populations with potential to perform different functions, including those related to the nitrogen cycling. One of our aims was to determine whether organic amendments create hotspots for bacterial functions related to bacterial nitrogen cycling. This pan of the project will be discussed in this presentation.

  2. Soil Aggregation, Organic Carbon Concentration, and Soil Bulk Density As Affected by Cover Crop Species in a No-Tillage System

    Directory of Open Access Journals (Sweden)

    Adriano Stephan Nascente

    2015-06-01

    Full Text Available Soil aggregation and the distribution of total organic carbon (TOC may be affected by soil tillage and cover crops. The objective of this study was to determine the effects of crop rotation with cover crops on soil aggregation, TOC concentration in the soil aggregate fractions, and soil bulk density under a no-tillage system (NTS and conventional tillage system (CTS, one plowing and two disking. This was a three-year study with cover crop/rice/cover crop/rice rotations in the Brazilian Cerrado. A randomized block experimental design with six treatments and three replications was used. The cover crops (treatments were: fallow, Panicum maximum, Brachiaria ruziziensis, Brachiaria brizantha, and millet (Pennisetum glaucum. An additional treatment, fallow plus CTS, was included as a control. Soil samples were collected at the depths of 0.00-0.05 m, 0.05-0.10 m, and 0.10-0.20 m after the second rice harvest. The treatments under the NTS led to greater stability in the soil aggregates (ranging from 86.33 to 95.37 % than fallow plus CTS (ranging from 74.62 to 85.94 %. Fallow plus CTS showed the highest number of aggregates smaller than 2 mm. The cover crops affected soil bulk density differently, and the millet treatment in the NTS had the lowest values. The cover crops without incorporation provided the greatest accumulation of TOC in the soil surface layers. The TOC concentration was positively correlated with the aggregate stability index in all layers and negatively correlated with bulk density in the 0.00-0.10 m layer.

  3. Soil Quality Indicators as Affected by a Long Term Barley-Maize and Maize Cropping Systems

    Directory of Open Access Journals (Sweden)

    Barbara Manachini

    2009-03-01

    Full Text Available Most soil studies aim a better characterization of the system through indicators. In the present study nematofauna and soil structure were chosen as indicators to be assess soil health as related to agricultural practices. The field research was carried out on the two fodder cropping systems continuous maize (CM, Zea mays L. and a 3-year rotation of silage-maize – silage-barley (Hordeum vulgare L. with Italian ryegrass (R3 and grain-maize maintained in these conditions for 18 years. Each crop system was submitted to two management options: 1 the high input level (H, done as a conventional tillage, 2 the low input level (L, where the tillage was replaced by harrowing and the manure was reduced by 30%. The effects of the two different cropping systems was assessed on soil nematofauna and soil physic parameters (structure or aggregate stability. Comparison was made of general composition, trophic structure and biodiversity of the nematofauna collected in both systems. Differences in nematode genera composition and distribution between the two systems were also recorded. The monoculture, compared to the three year rotation, had a negative influence on the nematofauna composition and its ecological succession. The Structural Stability Index (SSI values indicate that both the cropping systems had a negative effect on the aggregate stability. The results indicate that nematofauna can be used to assess the effects of cropping systems on soil ecosystem, and therefore be considered a good indicator of soil health to integrate information from different chemical or physical indicators.

  4. Soil Quality Indicators as Affected by a Long Term Barley-Maize and Maize Cropping Systems

    Directory of Open Access Journals (Sweden)

    Anna Corsini

    2011-02-01

    Full Text Available Most soil studies aim a better characterization of the system through indicators. In the present study nematofauna and soil structure were chosen as indicators to be assess soil health as related to agricultural practices. The field research was carried out on the two fodder cropping systems continuous maize (CM, Zea mays L. and a 3-year rotation of silage-maize – silage-barley (Hordeum vulgare L. with Italian ryegrass (R3 and grain-maize maintained in these conditions for 18 years. Each crop system was submitted to two management options: 1 the high input level (H, done as a conventional tillage, 2 the low input level (L, where the tillage was replaced by harrowing and the manure was reduced by 30%. The effects of the two different cropping systems was assessed on soil nematofauna and soil physic parameters (structure or aggregate stability. Comparison was made of general composition, trophic structure and biodiversity of the nematofauna collected in both systems. Differences in nematode genera composition and distribution between the two systems were also recorded. The monoculture, compared to the three year rotation, had a negative influence on the nematofauna composition and its ecological succession. The Structural Stability Index (SSI values indicate that both the cropping systems had a negative effect on the aggregate stability. The results indicate that nematofauna can be used to assess the effects of cropping systems on soil ecosystem, and therefore be considered a good indicator of soil health to integrate information from different chemical or physical indicators.

  5. Hindered Csbnd N bond rotation in triazinyl dithiocarbamates

    Science.gov (United States)

    Jung, Taesub; Do, Hee-Jin; Son, Jongwoo; Song, Jae Hee; Cha, Wansik; Kim, Yeong-Joon; Lee, Kyung-Koo; Kwak, Kyungwon

    2018-01-01

    The substituent and solvent effects on the rotation around a Csbnd N amide bond were studied for a series of triazine dibenzylcarbamodithioates. The Gibbs free energies (ΔG‡) were measured to be 16-18 kcal/mol in DMSO-d6 and toluene-d8 using variable-temperature nuclear magnetic resonance (VT-1H NMR) spectroscopy. Density functional theory (DFT) calculations reproduced the experimental observations with various substituents, as well as solvents. From the detailed analysis of the DFT results, we found that the electron donating dibenzyl amine group increased the electron population on the triazinyl ring, which decreased the rotational barrier of the Csbnd N bond in the dithiocarbamate group attached to the triazinyl ring. The higher electron population on the triazine moiety stabilizes the partial double bond character of the Ssbnd C bond, which competitively excludes the double bond character of the Csbnd N bond. Therefore, the rotational dynamics of the Csbnd N bond in dithiocarbamates can be a sensitive probe to small differences in the electron population of substituents on sulfur.

  6. Faraday rotation measurements at Ootacamund

    Science.gov (United States)

    Sethia, G.; Chandra, H.; Deshpande, M. R.; Rastogi, R. G.

    1978-01-01

    The results of Faraday rotation measurements made at Ootacamund during ATS-6 phase II are presented. For summer and equinoctial months, even though no clear noon bite-out is observed in the variation of Faraday a decrease is observed in the rate of increase of rotation around 0900-1000 hours LT. This is attributed to the 'fountain effect' which is responsible for the noontime bite-out in F2-region peak electron density.

  7. Effect of sugarcane cropping systems on herbicide losses in surface runoff.

    Science.gov (United States)

    Nachimuthu, Gunasekhar; Halpin, Neil V; Bell, Michael J

    2016-07-01

    Herbicide runoff from cropping fields has been identified as a threat to the Great Barrier Reef ecosystem. A field investigation was carried out to monitor the changes in runoff water quality resulting from four different sugarcane cropping systems that included different herbicides and contrasting tillage and trash management practices. These include (i) Conventional - Tillage (beds and inter-rows) with residual herbicides used; (ii) Improved - only the beds were tilled (zonal) with reduced residual herbicides used; (iii) Aspirational - minimum tillage (one pass of a single tine ripper before planting) with trash mulch, no residual herbicides and a legume intercrop after cane establishment; and (iv) New Farming System (NFS) - minimum tillage as in Aspirational practice with a grain legume rotation and a combination of residual and knockdown herbicides. Results suggest soil and trash management had a larger effect on the herbicide losses in runoff than the physico-chemical properties of herbicides. Improved practices with 30% lower atrazine application rates than used in conventional systems produced reduced runoff volumes by 40% and atrazine loss by 62%. There were a 2-fold variation in atrazine and >10-fold variation in metribuzin loads in runoff water between reduced tillage systems differing in soil disturbance and surface residue cover from the previous rotation crops, despite the same herbicide application rates. The elevated risk of offsite losses from herbicides was illustrated by the high concentrations of diuron (14μgL(-1)) recorded in runoff that occurred >2.5months after herbicide application in a 1(st) ratoon crop. A cropping system employing less persistent non-selective herbicides and an inter-row soybean mulch resulted in no residual herbicide contamination in runoff water, but recorded 12.3% lower yield compared to Conventional practice. These findings reveal a trade-off between achieving good water quality with minimal herbicide contamination and

  8. Diversified cropping systems support greater microbial cycling and retention of carbon and nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    King, Alison E.; Hofmockel, Kirsten S.

    2017-03-01

    Diversifying biologically simple cropping systems often entails altering other management practices, such as tillage regime or nitrogen (N) source. We hypothesized that the interaction of crop rotation, N source, and tillage in diversified cropping systems would promote microbially-mediated soil C and N cycling while attenuating inorganic N pools. We studied a cropping systems trial in its 10th year in Iowa, USA, which tested a 2-yr cropping system of corn (Zea mays L.)/soybean [Glycine max (L.) Merr.] managed with conventional fertilizer N inputs and conservation tillage, a 3-yr cropping system of corn/soybean/small grain + red clover (Trifolium pratense L.), and a 4-yr cropping system of corn/soybean/small grain + alfalfa (Medicago sativa L.)/alfalfa. Three year and 4-yr cropping systems were managed with composted manure, reduced N fertilizer inputs, and periodic moldboard ploughing. We assayed soil microbial biomass carbon (MBC) and N (MBN), soil extractable NH4 and NO3, gross proteolytic activity of native soil, and potential activity of six hydrolytic enzymes eight times during the growing season. At the 0-20cm depth, native protease activity in the 4-yr cropping system was greater than in the 2-yr cropping system by a factor of 7.9, whereas dissolved inorganic N pools did not differ between cropping systems (P = 0.292). At the 0-20cm depth, MBC and MBN the 4-yr cropping system exceeded those in the 2-yr cropping system by factors of 1.51 and 1.57. Our findings suggest that diversified crop cropping systems, even when periodically moldboard ploughed, support higher levels of microbial biomass, greater production of bioavailable N from SOM, and a deeper microbially active layer than less diverse cropping systems.

  9. Inter-ring rotations of AAA ATPase p97 revealed by electron cryomicroscopy.

    Science.gov (United States)

    Yeung, Heidi O; Förster, Andreas; Bebeacua, Cecilia; Niwa, Hajime; Ewens, Caroline; McKeown, Ciarán; Zhang, Xiaodong; Freemont, Paul S

    2014-03-05

    The type II AAA+ protein p97 is involved in numerous cellular activities, including endoplasmic reticulum-associated degradation, transcription activation, membrane fusion and cell-cycle control. These activities are at least in part regulated by the ubiquitin system, in which p97 is thought to target ubiquitylated protein substrates within macromolecular complexes and assist in their extraction or disassembly. Although ATPase activity is essential for p97 function, little is known about how ATP binding or hydrolysis is coupled with p97 conformational changes and substrate remodelling. Here, we have used single-particle electron cryomicroscopy (cryo-EM) to study the effect of nucleotides on p97 conformation. We have identified conformational heterogeneity within the cryo-EM datasets from which we have resolved two major p97 conformations. A comparison of conformations reveals inter-ring rotations upon nucleotide binding and hydrolysis that may be linked to the remodelling of target protein complexes.

  10. Congo grass grown in rotation with soybean affects phosphorus bound to soil carbon

    Directory of Open Access Journals (Sweden)

    Alexandre Merlin

    2014-06-01

    Full Text Available The phosphorus supply to crops in tropical soils is deficient due to its somewhat insoluble nature in soil, and addition of P fertilizers has been necessary to achieve high yields. The objective of this study was to examine the mechanisms through which a cover crop (Congo grass - Brachiaria ruziziensis in rotation with soybean can enhance soil and fertilizer P availability using long-term field trials and laboratory chemical fractionation approaches. The experimental field had been cropped to soybean in rotation with several species under no-till for six years. An application rate of no P or 240 kg ha-1 of P2O5 had been applied as triple superphosphate or as Arad rock phosphate. In April 2009, once more 0.0 or 80.0 kg ha-1 of P2O5 was applied to the same plots when Congo grass was planted. In November 2009, after Congo grass desiccation, soil samples were taken from the 0-5 and 5-10 cm depth layer and soil P was fractionated. Soil-available P increased to the depth of 10 cm through growing Congo grass when P fertilizers were applied. The C:P ratio was also increased by the cover crop. Congo grass cultivation increased P content in the soil humic fraction to the depth of 10 cm. Congo grass increases soil P availability by preventing fertilizer from being adsorbed and by increasing soil organic P.

  11. Cropping Systems and Climate Change in Humid Subtropical Environments

    Directory of Open Access Journals (Sweden)

    Ixchel M. Hernandez-Ochoa

    2018-02-01

    Full Text Available In the future, climate change will challenge food security by threatening crop production. Humid subtropical regions play an important role in global food security, with crop rotations often including wheat (winter crop and soybean and maize (summer crops. Over the last 30 years, the humid subtropics in the Northern Hemisphere have experienced a stronger warming trend than in the Southern Hemisphere, and the trend is projected to continue throughout the mid- and end of century. Past rainfall trends range, from increases up to 4% per decade in Southeast China to −3% decadal decline in East Australia; a similar trend is projected in the future. Climate change impact studies suggest that by the middle and end of the century, wheat yields may not change, or they will increase up to 17%. Soybean yields will increase between 3% and 41%, while maize yields will increase by 30% or decline by −40%. These wide-ranging climate change impacts are partly due to the region-specific projections, but also due to different global climate models, climate change scenarios, single-model uncertainties, and cropping system assumptions, making it difficult to make conclusions from these impact studies and develop adaptation strategies. Additionally, most of the crop models used in these studies do not include major common stresses in this environment, such as heat, frost, excess water, pests, and diseases. Standard protocols and impact assessments across the humid subtropical regions are needed to understand climate change impacts and prepare for adaptation strategies.

  12. [Rotator cuff tear athropathy prevalence].

    Science.gov (United States)

    Guerra-Soriano, F; Encalada-Díaz, M I; Ruiz-Suárez, M; Valero-González, F S

    2017-01-01

    Glenohumeral arthritis secondary to massive rotator cuff tear presents with a superior displacement and femoralization of the humeral head with coracoacromial arch acetabularization. The purpose of this study was to establish prevalence of rotator cuff tear artropathy (CTA) at our institution. Four hundred electronic records were reviewed from which we identified 136 patients with rotator cuff tears. A second group was composed with patients with massive cuff tears that were analized and staged by the Seebauer cuff tear arthropathy classification. Thirty four patients with massive rotator cuff tears were identified, 8 male and 26 female (age 60.1 ± 10.26 years). Massive rotator cuff tear prevalence was 25%. CTA prevalence found in the rotator cuff group was 19 and 76% in the massive cuff tears group. Patients were staged according to the classification with 32% in stage 1a, 11% 1b, 32% 2a and 0% 2b. CTA prevalence in patients with rotator cuff tears and massive cuff tears is higher than the one reported in American population. We consider that a revision of the Seebauer classification to be appropriate to determine its reliability.

  13. Rotational discontinuities in anisotropic plasmas

    International Nuclear Information System (INIS)

    Omidi, N.

    1992-01-01

    The kinetic structure of rotational discontinuities (RDs) in anisotropic plasmas with T perpendicular /T parallel > 1 is investigated by using a one-dimensional electromagnetic hybrid code. To form the RD, a new approach is used where the plasma is injected from one boundary and reflected from the other, resulting in the generation of a traveling fast shock and an RD. Unlike the previously used methods, no a priori assumptions are made regarding the initial structure (i.e. width or sense of rotation) of the rotational discontinuity. The results show that across the RD both the magnetic field strength and direction, as well as the plasma density change. Given that such a change can also be associated with an intermediate shock, the Rankine-Hugoniot relations are used to confirm that the observed structures are indeed RDs. It is found that the thickness of RDs is a few ion inertial lengths and is independent of the rotation angle. Also, the preferred sense of rotation is in the electron sense; however, RDs with a rotation angle larger than 180 degree are found to be unstable, changing their rotation to a stable ion sense

  14. Sub-soil microbial activity under rotational cotton crops in Australia

    Science.gov (United States)

    Polain, Katherine; Knox, Oliver; Wilson, Brian; Pereg, Lily

    2016-04-01

    Soil microbial communities contribute significantly to soil organic matter formation, stabilisation and destabilisation, through nutrient cycling and biodegradation. The majority of soil microbial research examines the processes occurring in the top 0 cm to 30 cm of the soil, where organic nutrients are easily accessible. In soils such as Vertosols, the high clay content causes swelling and cracking. When soil cracking is coupled with rain or an irrigation event, a flush of organic nutrients can move down the soil profile, becoming available for subsoil microbial community use and potentially making a significant contribution to nutrient cycling and biodegradation in soils. At present, the mechanisms and rates of soil nutrient turnover (such as carbon and nitrogen) at depth under cotton rotations are mostly speculative and the process-response relationships remain unclear, although they are undoubtedly underpinned by microbial activity. Our research aims to determine the contribution and role of soil microbiota to the accumulation, cycling and mineralisation of carbon and nitrogen through the whole root profile under continuous cotton (Gossypium hirsutum) and cotton-maize rotations in regional New South Wales, Australia. Through seasonal work, we have established both baseline and potential microbial activity rates from 0 cm to 100 cm down the Vertosol profile, using respiration and colourimetric methods. Further whole soil profile analyses will include determination of microbial biomass and isotopic carbon signatures using phospholipid fatty acid (PLFA) methodology, identification of microbial communities (sequencing) and novel experiments to investigate potential rates of nitrogen mineralisation and quantification of associated genes. Our preliminary observations and the hypotheses tested in this three-year study will be presented.

  15. Plasma rotation and rf heating in DIII-D

    International Nuclear Information System (INIS)

    DeGrassie, J.S.; Baker, D.R.; Burrell, K.H.

    1999-05-01

    In a variety of discharge conditions on DIII-D it is observed that rf electron heating reduces the toroidal rotation speed and core ion temperature. The rf heating can be with either fast wave or electron cyclotron heating and this effect is insensitive to the details of the launched toroidal wavenumber spectrum. To date all target discharges have rotation first established with co-directed neutral beam injection. A possible cause is enhanced ion momentum and thermal diffusivity due to electron heating effectively creating greater anomalous viscosity. Another is that a counter directed toroidal force is applied to the bulk plasma via rf driven radial current

  16. Plasma rotation and rf heating in DIII-D

    International Nuclear Information System (INIS)

    Grassie, J. S. de; Baker, D. R.; Burrell, K. H.; Greenfield, C. M.; Lin-Liu, Y. R.; Luce, T. C.; Petty, C. C.; Prater, R.; Heidbrink, W. W.; Rice, B. W.

    1999-01-01

    In a variety of discharge conditions on DIII-D it is observed that rf electron heating reduces the toroidal rotation speed and core ion temperature. The rf heating can be with either fast wave or electron cyclotron heating and this effect is insensitive to the details of the launched toroidal wavenumber spectrum. To date all target discharges have rotation first established with co-directed neutral beam injection. A possible cause is enhanced ion momentum and thermal diffusivity due to electron heating effectively creating greater anomalous viscosity. Another is that a counter directed toroidal force is applied to the bulk plasma via rf driven radial current. (c) 1999 American Institute of Physics

  17. Addressing crop interactions within cropping systems in LCA

    DEFF Research Database (Denmark)

    Goglio, Pietro; Brankatschk, Gerhard; Knudsen, Marie Trydeman

    2018-01-01

    objectives of this discussion article are as follows: (i) to discuss the characteristics of cropping systems which might affect the LCA methodology, (ii) to discuss the advantages and the disadvantages of the current available methods for the life-cycle assessment of cropping systems, and (iii) to offer...... management and emissions, and (3) functional unit issues. The LCA approaches presented are as follows: cropping system, allocation approaches, crop-by-crop approach, and combined approaches. The various approaches are described together with their advantages and disadvantages, applicability...... considers cropping system issues if they are related to multiproduct and nutrient cycling, while the crop-by-crop approach is highly affected by assumptions and considers cropping system issues only if they are related to the analyzed crop. Conclusions Each LCA approach presents advantages and disadvantages...

  18. Measurement of total electron content of midlatitude ionosphere and protonosphere via Faraday rotation and group relay techniques using transmission from geostationary satellites ATS-3 and ATS-6

    Science.gov (United States)

    Paul, M. P.

    1982-01-01

    Measurement of integrated columnar electron content and total electron content for the local ionosphere and the overlying protonosphere via Faraday rotation and group delay techniques has proven very useful. A field station was established having the geographic location of 31.5 deg N latitude and 91.06 deg W longitude to accomplish these objectives. A polarimeter receiving system was set up in the beginning to measure the Faraday rotation of 137.35 MHz radio signal from geostationary satellite ATS 3 to yield the integrated columnar electron content of the local ionosphere. The measurement was continued regularly, and the analysis of the data thus collected provided a synopsis of the statistical variation of the ionosphere along with the transient variations that occurred during the periods of geomagnetic and other disturbances.

  19. Increases of soil phosphatase and urease activities in potato fields by cropping rotation practices

    Science.gov (United States)

    Potato yield in Maine has remained relatively constant for over 50 years. To identify and quantify constraints to potato productivity, we established Status Quo (SQ), Soil Conserving (SC), Soil Improving (SI), Disease Suppressive (DS), and Continuous Potato (PP) cropping systems under both rainfed ...

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

    OpenAIRE

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

    2010-01-01

    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 inc...

  1. Hemp: A more sustainable annual energy crop for climate and energy policy

    International Nuclear Information System (INIS)

    Finnan, John; Styles, David

    2013-01-01

    The objective of this study was to compare the fuel-chain greenhouse gas balance and farm economics of hemp grown for bioenergy with two perennial bioenergy crops, Miscanthus and willow, and two more traditional annual bioenergy crops, sugar beet and oil seed rape (OSR). The GHG burden of hemp cultivation is intermediate between perennial and traditional annual energy crops, but net fuel chain GHG abatement potential of 11 t/CO 2 eq./ha/year in the mid yield estimate is comparable to perennial crops, and 140% and 540% greater than for OSR and sugar beet fuel chains, respectively. Gross margins from hemp were considerably lower than for OSR and sugar beet, but exceeded those from Miscanthus when organic fertilizers were used and in the absence of establishment grants for the latter crop. Extrapolated up to the EU scale, replacing 25% of OSR and sugar beet production with hemp production could increase net GHG abatement by up to 21 Mt CO 2 eq./year. Hemp is a considerably more efficient bioenergy feedstock than the dominant annual energy crops. Integrated into food crop rotations, hemp need not compete with food supplies, and could provide an appealing option to develop more sustainable non-transport bioenergy supply chains. - Highlights: ► The GHG burden of hemp is intermediate between perennial and annual energy crops. ► Replacing 25% of OSR/beet with hemp could increase GHG abatement by 21 Mt/CO 2 eq./year. ► Hemp is a more efficient bioenergy feedstock than the dominant annual energy crops

  2. Short-rotation coppicing in France. Current state of research and prospects for future development

    Energy Technology Data Exchange (ETDEWEB)

    Bonduelle, P. (Association Foret Cellulose, Trelaze (France)); Bouvarel, L. (Institut National de la Recherche Agronomique, Olivet (France). Unite Experimentale Biomasse, Forestiere et Foret Paysanne); Petit, H. (Association pour la Rationalisation et la Mecanisation de l' Exploitation Forestiere, Fontainebleau (France)); Pierson, J. (Cellulose des Ardennes, Montemedy (France)); Savanne, D. (Agence de l' Environnement et de la Maitrise de l' Energie, 75 - Paris (France)); Sourie, J.C. (Institut National de la Recherche Agronomique, Grignon (France). Station d' Economie et de Sociologie Rurales)

    1992-01-01

    This article analyzes the current context and the prospects for crop development as well as offering a number of examples of short rotation coppicing projects. The industrial outlets created through state aid remain the primary driving force behind plantations at this time. (author)

  3. Molecular Viscosity Sensors with Two Rotators for Optimizing the Fluorescence Intensity-Contrast Trade-Off.

    Science.gov (United States)

    Lee, Seung-Chul; Lee, Chang-Lyoul; Heo, Jeongyun; Jeong, Chan-Uk; Lee, Gyeong-Hui; Kim, Sehoon; Yoon, Woojin; Yun, Hoseop; Park, Sung O; Kwak, Sang Kyu; Park, Sung-Ha; Kwon, O-Pil

    2018-02-26

    A series of fluorescent molecular rotors obtained by introducing two rotational groups ("rotators"), which exhibit different rotational and electron-donating abilities, are discussed. Whereas the control molecular rotor, PH, includes a single rotator (the widely used phenyl group), the PO molecular rotors consist of two rotators (a phenyl group and an alkoxy group), which exhibit simultaneous strongly electron-donating and easy rotational abilities. Compared with the control rotor PH, PO molecular rotors exhibited one order of magnitude higher quantum yield (fluorescence intensity) and simultaneously exhibited significantly higher fluorescence contrast. These properties are directly related to the strong electron-donating ability and low energy barrier of rotation of the alkoxy group, as confirmed by dynamic fluorescence experiments and quantum chemical calculations. The PO molecular rotors exhibited two fluorescence relaxation pathways, whereas the PH molecular rotor exhibited a single fluorescence relaxation pathway. Cellular fluorescence imaging with PO molecular rotors for mapping cellular viscosity was successfully demonstrated. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Harvesting fertilized rye cover crop: simulated revenue, net energy, and drainage Nitrogen loss

    Science.gov (United States)

    Food and biofuel production along with global N use are expected to increase over the next few decades, which complicates the goal of reducing N loss to the environment. Including winter rye as a cover crop in corn-soybean rotations reduces N loss to drainage. A few studies suggest that harvesting r...

  5. Investigation of Sensitivity of Some Pulses and Agronomic Crops to Soil Residue of Idosulfuron-mesosulfurun Herbicide

    Directory of Open Access Journals (Sweden)

    E. Izadi-Darbandi

    2013-03-01

    Full Text Available To study the sensitivity of chick pea, bean, lentil, rapeseed, sugarbeet and tomato to soil residual concentration of Idosulfuron-mesosulfurun herbicide, an experiment was carried out under controlled conditions at the College of Agriculture, Ferdowsi University of Mashhad, Iran, in 2010. The studied factors were the 6 mentioned crops, and 7 levels of soil residual concentration of Idosulfuron-mesosulfurun herbicide (0, 0.0015, 0.0037, 0.0079, 0.015, 0.031 and 0.047 mg per kg of soil. The factorial experiment was carried out as a completely randomized design with three replications. Crops' emergence percentage was determined one week after their emergence. Plants' survival percentage and shoot and root biomass production were measured 30 days after their emergence. Results showed that all mentioned characteristics decreased significantly (P<0.01 in the presence of soil residue of the herbicide. Increasing Idosulfuron-mesosulfurun residual concentration in soil decreased emergence and shoot and root biomass production. Bean had the lowest shoot (44% and root (66.78% biomass loss and tomato had the highest shoot (96.38% and root (89.64% biomass loss. Based on ED50 index, pea (0.0079 mg/kg soil was the most tolerant and tomato (0.0003 mg/kg soil was the most susceptible crop to soil residues of Idosulfuron-mesosulfurun, and other crops ranked in between as: tomato< sugarbeet< rapeseed< lentil< bean< pea. In general, these results showed that soil residue of Idosulfuron-mesosulfurun can injure rotation crops and it is important to consider their sensitivity in rotation programming.

  6. Partitioning of methyl internal rotational barrier energy of ...

    Indian Academy of Sciences (India)

    The nature of methyl internal rotational barrier in thioacetaldehyde has been investigated by relaxation effect, natural bond orbital (NBO) analysis and Pauling exchange interactions. The true experimental barrier can be obtained by considering fully relaxed rotation. Nuclear-electron attraction term is a barrier forming term in ...

  7. Plant production, production energy, energy crops - approaches toward intelligent use of energy crops in bioenergy systems; Pflanzenproduktion, Produktionsenergie, Energiepflanzen - Ansaetze intelligenter Energiepflanzennutzung in Bioenergie-Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Scheibler, M. [ENTEC Environment Technology Umwelttechnik GmbH, Fussach (Austria); Priedl, J.

    2002-12-01

    Food surplus production in the European Union should be replaced by biomass plantation for biogas production. The choice of energy plants like sunflowers or triticale and the harvesting time depends on soils, microclimates and crop rotation. The authors present a consultance package for planning, construction and operation of a Complete Stirred Reactor for biomass fermentation. Investment and operating cost depend on plant size and degree of automation. (uke)

  8. Forms of phosphorus in an oxisol under different soil tillage systems and cover plants in rotation with maize

    Directory of Open Access Journals (Sweden)

    Arminda Moreira de Carvalho

    2014-06-01

    Full Text Available Phosphorus fractions play a key role in sustaining the productivity of acid-savanna Oxisols and are influenced by tillage practices. The aim of this study was to quantify different P forms in an Oxisol (Latossolo Vermelho-Amarelo from the central savanna region of Brazil under management systems with cover crops in maize rotation. Three cover crops (Canavalia brasiliensis, Cajanus cajan (L., and Raphanus sativus L. were investigated in maize rotation systems. These cover crops were compared to spontaneous vegetation. The inorganic forms NaHCO3-iP and NaOH-iP represented more than half of the total P in the samples collected at the depth of 5-10 cm during the rainy season when the maize was grown. The concentration of inorganic P of greater availability (NaHCO3-iP and NaOH-iP was higher in the soil under no-tillage at the depth of 5-10 cm during the rainy season. Concentrations of organic P were higher during the dry season, when the cover crops were grown. At the dry season, organic P constituted 70 % of the labile P in the soil planted to C. cajan under no-tillage. The cover crops were able to maintain larger fractions of P available to the maize, resulting in reduced P losses to the unavailable pools, mainly in no-tillage systems.

  9. Spider assemblages associated with different crop stages of irrigated rice agroecosystems from eastern Uruguay.

    Science.gov (United States)

    Bao, Leticia; Ginella, Juaquín; Cadenazzi, Mónica; Castiglioni, Enrique A; Martínez, Sebastián; Casales, Luis; Caraballo, María P; Laborda, Álvaro; Simo, Miguel

    2018-01-01

    The rice crop and associated ecosystems constitute a rich mosaic of habitats that preserve a rich biological diversity. Spiders are an abundant and successful group of natural predators that are considered efficient in the biocontrol of the major insect pests in agroecosystems. Spider diversity in different stages of the rice crop growth from eastern Uruguay was analysed. Field study was developed on six rice farms with rotation system with pasture, installed during intercropping stage as cover crop. Six rice crops distributed in three locations were sampled with pitfall and entomological vaccum suction machine. Sixteen families, representing six guilds, were collected. Lycosidae, Linyphiidae, Anyphaenidae and Tetragnathidae were the most abundant families (26%, 25%, 20% and 12%, respectively) and comprised more than 80% of total abundance. Other hunters (29%), sheet web weavers (25%) and ground hunters (24%) were the most abundant guilds. Species composition along different crop stages was significantly different according to the ANOSIM test. The results showed higher spider abundance and diversity along the crop and intercrop stages. This study represents the first contribution to the knowledge of spider diversity associated with rice agroecosystem in the country.

  10. Replacing fallow by cover crops: economic sustainability

    Science.gov (United States)

    Gabriel, José Luis; Garrido, Alberto; Quemada, Miguel

    2013-04-01

    Replacing fallow by cover crops in intensive fertilized systems has been demonstrated as an efficient tool for reducing nitrate leaching. However, despite the evident environmental services provided and the range of agronomic benefits documented in the literature, farmers' adoption of this new technology is still limited because they are either unwilling or unable, although adoption reluctance is frequently rooted in low economic profitability, low water se efficiency or poor knowledge. Economic analyses permit a comparison between the profit that farmers obtain from agricultural products and the cost of adopting specific agricultural techniques. The goal of this study was to evaluate the economic impact of replacing the usual winter fallow with cover crops (barley (Hordeum vulgare L., cv. Vanessa), vetch (Vicia villosa L., cv. Vereda) and rapeseed (Brassica napus L., cv. Licapo)) in irrigated maize systems and variable Mediterranean weather conditions using stochastic Monte-Carlo simulations of key farms' financial performance indicators. The three scenarios studied for each cover crop were: i) just leaving the cover crop residue in the ground, ii) leaving the cover crop residue but reduce following maize fertilization according to the N available from the previous cover crop and iii) selling the cover crop residue for animal feeding. All the scenarios were compared with respect to a typical maize-fallow rotation. With observed data from six different years and in various field trials, looking for different weather conditions, probability distribution functions of maize yield, cover crop biomass production and N fertilizer saving was fitted. Based in statistical sources maize grain price, different forage prices and the cost of fertilizer were fitted to probability distribution functions too. As result, introducing a cover crop involved extra costs with respect to fallow as the initial investment, because new seed, herbicide or extra field operations. Additional

  11. The silviculture, nutrition and economics of short rotation willow coppice in the uplands of mid-Wales

    Energy Technology Data Exchange (ETDEWEB)

    Heaton, R J; Randerson, P F; Slater, F M

    2000-07-01

    The potential of short rotation coppice as a biomass crop on land over 250m (the uplands) of mid Wales was studied. The results found in this study indicate that growing short rotation coppice willow in the uplands is a viable proposition with regard to establishment success and yields. In the event of a secure wood chip market in Wales, returns to the grower would be comparable to those from sheep production. (author)

  12. Soil Carbon Changes in Transitional Grain Crop Production Systems in South Dakota

    Science.gov (United States)

    Woodard, H. J.

    2004-12-01

    Corn-C (Zea Mays L.), soybean-S (Glycine max L.) and spring wheat-W (Triticum aestivum L.) crops were seeded as a component of either a C-S, S-W, or C-S-W crop rotation on silt-loam textured soils ranging from 3.0-5.0% organic matter. Conservation tillage(chisel plow-field cultivator) was applied to half of the plots. The other plots were direct seeded as a no-till (zero-tillage) treatment. Grain yield and surface crop residues were weighed from each treatment plot. Crop residue (stover and straw) was removed from half of the plots. After four years, soil samples were removed at various increments of depth and soil organic carbon (C) and nitrogen (N) was measured. The ranking of crop residue weights occurred by the order corn>>soybean>wheat. Surface residue accumulation was also greatest with residue treatments that were returned to the plots, those rotations in which maize was a component, and those without tillage. Mean soil organic carbon levels in the 0-7.5cm depth decreased from 3.41% to 3.19% (- 0.22%) with conventional tillage (chisel plow/field cultivator) as compared to a decrease from 3.19% to 3.05% (-0.14%) in plots without tillage over a four year period. Organic carbon in the 0-7.5cm depth decreased from 3.21% to 3.01% (- 0.20%) after residue removed as compared to a decrease from 3.39% to 3.23% (-0.17%) in plots without tillage applied after four years. The soil C:N ratio (0-7.5cm) decreased from 10.63 to 10.37 (-0.26 (unitless)) in the tilled plots over a four-year period. Soil C:N ratio at the 0-7.5cm depth decreased from 10.72 to 10.04 (-0.68) in the no-till plots over a four year period. Differences in the soil C:N ratio comparing residue removed and residue returned were similar (-0.51 vs. -0.43 respectively). These soils are highly buffered for organic carbon changes. Many cropping cycles are required to determine how soil carbon storage is significantly impacted by production systems.

  13. An evaluation of herbicides for post-emergence use in short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, D.J.

    2000-07-01

    The objective of the project was to evaluate the safety and efficacy of a range of herbicides and mixtures of herbicides, with both contact and residual activity, for the post-emergence control of weeds in newly planted willow short rotation coppice (SRC). This report provides growers and advisers of short rotation coppice with important (but still limited) information on how to achieve improved weed control of problem weeds increasingly prevalent in SRC fields. This may provide guidance towards often-essential emergency treatments when the crop establishment is under considerable pressure and the potential safety, or otherwise, of certain weed-specific herbicides. (author)

  14. Sustainability assessment of GM crops in a Swiss agricultural context

    OpenAIRE

    Speiser , Bernhard; Stolze , Matthias; Oehen , Bernadette; Gessler , Cesare; Weibel , Franco; Bravin , Esther; Kilchenmann , Adeline; Widmer , Albert; Charles , Raffael; Lang , Andreas; Stamm , Christian; Triloff , Peter; Tamm , Lucius

    2012-01-01

    International audience; The aim of this study was to provide an ex ante assessment of the sustainability of genetically modified (GM) crops under the agricultural conditions prevailing in Switzerland. The study addressed the gaps in our knowledge relating to (1) the agronomic risks/benefits in production systems under Swiss conditions (at field and rotation/orchard level), (2) the economic and socio-economic impacts associated with altered farming systems, and (3) the agro-ecological risks/be...

  15. Rotational Parameters from Vibronic Eigenfunctions of Jahn-Teller Active Molecules

    Science.gov (United States)

    Garner, Scott M.; Miller, Terry A.

    2017-06-01

    The structure in rotational spectra of many free radical molecules is complicated by Jahn-Teller distortions. Understanding the magnitudes of these distortions is vital to determining the equilibrium geometric structure and details of potential energy surfaces predicted from electronic structure calculations. For example, in the recently studied {\\widetilde{A}^2E^{''} } state of the NO_3 radical, the magnitudes of distortions are yet to be well understood as results from experimental spectroscopic studies of its vibrational and rotational structure disagree with results from electronic structure calculations of the potential energy surface. By fitting either vibrationally resolved spectra or vibronic levels determined by a calculated potential energy surface, we obtain vibronic eigenfunctions for the system as linear combinations of basis functions from products of harmonic oscillators and the degenerate components of the electronic state. Using these vibronic eigenfunctions we are able to predict parameters in the rotational Hamiltonian such as the Watson Jahn-Teller distortion term, h_1, and compare with the results from the analysis of rotational experiments.

  16. Sorghum - An alternative energy crop for marginal lands and reclamation sites

    Science.gov (United States)

    Lukas, Stefan; Theiß, Markus; Jäkel, Kerstin

    2017-04-01

    The production of biogas and the associated cultivation of energy crops are still of great importance. Considering increasing restrictions for the cultivation of standard biogas crop maize regarding an environmentally friendly production of biomass, a wider range of energy crops is needed. The cultivation of sorghum can contribute to this. As maize, sorghum is a C4-plant and offers a high biomass yield potential. Originated in the semi-arid tropics, sorghum is well adapted to warm and dry climate and particularly noted for its drought tolerance compared to maize. It also makes few demands on soil quality and shows a good capability of nutrient acquisition. Therefore, particularly on marginal areas and reclamation sites with low soil nutrient and water content sorghum can contribute to secure crop yield and income of farmers. The applied research project aims at and reflects on the establishment of sorghum as a profitable and ecological friendly cropping alternative to maize, especially in the face of probable climate change with increasing risks for agriculture. For this purpose, site differentiated growing and cultivar trials with a standardized planting design as well as several practical on-farm field experiments were conducted. The agronomical and economic results will lead to scientifically based procedures and standards for agricultural practice with respect to cultivation methods (drilling, pest-management, fertilization), cropping sequence and technique, cropping period or position in crop rotation. Even by now there is a promising feedback from the agricultural practice linked with an increasing demand for information. Moreover, the specific cropping area is increasing continuously. Therefore, the leading signs for the establishment of sorghum as profitable alternative to maize biogas production are positive. Sorghum cultures perform best as main crops in the warm D locations in the middle and East German dry areas. Here, the contribution margin

  17. Cropping Systems Dynamics in the Lower Gangetic Plains of India using Geospatial Technologies

    Directory of Open Access Journals (Sweden)

    K. R. Manjunath

    2012-08-01

    Full Text Available Cropping system study is useful to understand the overall sustainability of agricultural system. Capturing the change dynamics of cropping systems, especially spatial and temporal aspects, is of utmost importance in overall planning and management of natural resources. This paper highlights the remote sensing based cropping systems change-dynamics assessment. Current study is aimed at use of multidate-multisensor data for deriving the seasonal cropping pattern maps and deriving the remote sensing based cropping system performance indicators during 1998–99 and 2004–05 in West- Bengal state of India. The temporal assessment of the changes of cropping systems components such as cropping pattern and indices for the study years 1998–99 and 2004–05 have been brought out. The results indicate that during the six years of time the kharif cropping pattern has almost remained the same, being a rice dominant system. A notable point is the decrease in the aus rice due to readjusting the cropping system practice to suit the two crop systems in many places was observed. Marginal variations in mustard and wheat areas during rabi season was observed. The boro (summer rice area has almost remained constant. The rice-fallow-fallow (R-F-F rotation reduced by about 4 percent while the rice-fallow-rice (R-F-R increased by about 7 percent percent. The Area Diversity Index reduced by about 38 percent in 2004 which may be attributed to decrease in kharif pulses and minor crops during kharif and summer. However, diversity during rabi season continued to remain high. The increase in Multiple Cropping Index was observed predominantly in the southern part of the state. Cultivated Land Utilization Index shows an increase by about 0.05.

  18. Root Parameters Show How Management Alters Resource Distribution and Soil Quality in Conventional and Low-Input Cropping Systems in Central Iowa.

    Directory of Open Access Journals (Sweden)

    Patricia A Lazicki

    Full Text Available Plant-soil relations may explain why low-external input (LEI diversified cropping systems are more efficient than their conventional counterparts. This work sought to identify links between management practices, soil quality changes, and root responses in a long-term cropping systems experiment in Iowa where grain yields of 3-year and 4-year LEI rotations have matched or exceeded yield achieved by a 2-year maize (Zea mays L. and soybean (Glycine max L. rotation. The 2-year system was conventionally managed and chisel-ploughed, whereas the 3-year and 4-year systems received plant residues and animal manures and were periodically moldboard ploughed. We expected changes in soil quality to be driven by organic matter inputs, and root growth to reflect spatial and temporal fluctuations in soil quality resulting from those additions. We constructed a carbon budget and measured soil quality indicators (SQIs and rooting characteristics using samples taken from two depths of all crop-phases of each rotation system on multiple dates. Stocks of particulate organic matter carbon (POM-C and potentially mineralizable nitrogen (PMN were greater and more evenly distributed in the LEI than conventional systems. Organic C inputs, which were 58% and 36% greater in the 3-year rotation than in the 4-year and 2-year rotations, respectively, did not account for differences in SQI abundance or distribution. Surprisingly, SQIs did not vary with crop-phase or date. All biochemical SQIs were more stratified (p<0.001 in the conventionally-managed soils. While POM-C and PMN in the top 10 cm were similar in all three systems, stocks in the 10-20 cm depth of the conventional system were less than half the size of those found in the LEI systems. This distribution was mirrored by maize root length density, which was also concentrated in the top 10 cm of the conventionally managed plots and evenly distributed between depths in the LEI systems. The plow-down of organic amendments

  19. Atributos físicos do solo em sistemas de manejo de solo e de rotação de culturas Soil tillage and crop rotation systems on the soil physical attributes

    Directory of Open Access Journals (Sweden)

    Silvio Tulio Spera

    2009-01-01

    attributes were assessed after twenty years of implementation (1985 to 2005 on a typical Dystrophic Red Latosol (Rodic Hapludox located in Passo Fundo, Rio Grande do Sul State, Brazil. Four soil tillage systems were evaluated: 1 no-tillage; 2 minimum tillage; 3 conventional tillage using a disk plow plus disk harrow, and 4 conventional tillage using a moldboard plow plus disk harrow. Three crop rotation systems were evaluated: I (wheat/soybean, II (wheat/soybean and common vetch/corn or sorghum, and III (wheat/soybean, common vetch/corn or sorghum and white oats/soybean. A randomized complete block design, with split-plots and three replicates, was used. The main plots were formed by the soil tillage systems, while split-plots were composed by crop rotation systems. As control, soil samples were collected in a subtropical forest fragment adjacent to the experiment. Soil tillage systems and crop rotation systems influenced soil physical parameters when compared to the samples collected in a fragment of subtropical forest. During four years (2001 to 2005 the physical attributes were altered among different soil tillage management. The no-tillage system (PD presented higher soil bulk density and microporosity in comparison to the other systems, mainly in 0.10 to 0.15 m layer, characterizing high soil compaction levels. Crop systems did not promote favorable changes in physical attributes independent of the type of soil management.

  20. Evidence of Wigner rotation phenomena in the beam splitting experiment at the LCLS

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2016-07-01

    A result from particle tracking states that, after a microbunched electron beam is kicked, its trajectory changes while the orientation of the microbunching wavefront remains as before. Experiments at the LCLS showed that radiation in the kicked direction is produced practically without suppression. This could be explained if the orientation of the microbunching wavefront is readjusted along the kicked direction. In previous papers we showed that when the evolution of the electron beam modulation is treated according to relativistic kinematics, the orientation of the microbunching wavefront in the ultrarelativistic asymptotic is always perpendicular to the electron beam velocity. There we refrained from using advanced theoretical concepts to explain or analyze the wavefront rotation. For example, we only hinted to the relation of this phenomenon with the concept of Wigner rotation. This more abstract view of wavefront rotation underlines its elementary nature. The Wigner rotation is known as a fundamental effect in elementary particle physics. The composition of non collinear boosts does not result in a simple boost but, rather, in a Lorentz transformation involving a boost and a rotation, the Wigner rotation. Here we show that during the LCLS experiments, a Wigner rotation was actually directly recorded for the first time with a ultrarelativistic, macroscopic object: an ultrarelativistic electron bunch in an XFEL modulated at nm-scale of the size of about 10 microns. Here we point out the role of Wigner rotation in the analysis and interpretation of experiments with ultrarelativistic, microbunched electron beams in FELs. After the beam splitting experiment at the LCLS it became clear that, in the ultrarelativistic asymptotic, the projection of the microbunching wave vector onto the beam velocity is a Lorentz invariant, similar to the helicity in particle physics.

  1. Evidence of Wigner rotation phenomena in the beam splitting experiment at the LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-07-15

    A result from particle tracking states that, after a microbunched electron beam is kicked, its trajectory changes while the orientation of the microbunching wavefront remains as before. Experiments at the LCLS showed that radiation in the kicked direction is produced practically without suppression. This could be explained if the orientation of the microbunching wavefront is readjusted along the kicked direction. In previous papers we showed that when the evolution of the electron beam modulation is treated according to relativistic kinematics, the orientation of the microbunching wavefront in the ultrarelativistic asymptotic is always perpendicular to the electron beam velocity. There we refrained from using advanced theoretical concepts to explain or analyze the wavefront rotation. For example, we only hinted to the relation of this phenomenon with the concept of Wigner rotation. This more abstract view of wavefront rotation underlines its elementary nature. The Wigner rotation is known as a fundamental effect in elementary particle physics. The composition of non collinear boosts does not result in a simple boost but, rather, in a Lorentz transformation involving a boost and a rotation, the Wigner rotation. Here we show that during the LCLS experiments, a Wigner rotation was actually directly recorded for the first time with a ultrarelativistic, macroscopic object: an ultrarelativistic electron bunch in an XFEL modulated at nm-scale of the size of about 10 microns. Here we point out the role of Wigner rotation in the analysis and interpretation of experiments with ultrarelativistic, microbunched electron beams in FELs. After the beam splitting experiment at the LCLS it became clear that, in the ultrarelativistic asymptotic, the projection of the microbunching wave vector onto the beam velocity is a Lorentz invariant, similar to the helicity in particle physics.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    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)

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

    Science.gov (United States)

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

    2013-09-01

    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.

  4. Equilibrium and stability of a rotating plasma

    International Nuclear Information System (INIS)

    Janssen, P.A.E.M.

    1979-01-01

    The author considers the equilibrium and stability of a rotating plasma. The kinetic equations for ions and electrons supplemented with the Maxwell equations and the appropriate boundary conditions are used. Two different models for the rotating plasma are considered: the equilibrium of a 'fast' rotating plasma (Magneto Hydrodynamic ordering) and the stability of a slowly rotating, 'weakly' unstable plasma (Finite Larmor Radius ordering). A striking difference between these orderings is the fact that, regarding the stability of the plasma, for a F.L.R. plasma viscosity effects due to the finite Larmor radius are important, whereas in a M.H.D. plasma they are negligible (at least to the required order). (Auth.)

  5. Cover crops support ecological intensification of arable cropping systems

    Science.gov (United States)

    Wittwer, Raphaël A.; Dorn, Brigitte; Jossi, Werner; van der Heijden, Marcel G. A.

    2017-02-01

    A major challenge for agriculture is to enhance productivity with minimum impact on the environment. Several studies indicate that cover crops could replace anthropogenic inputs and enhance crop productivity. However, so far, it is unclear if cover crop effects vary between different cropping systems, and direct comparisons among major arable production systems are rare. Here we compared the short-term effects of various cover crops on crop yield, nitrogen uptake, and weed infestation in four arable production systems (conventional cropping with intensive tillage and no-tillage; organic cropping with intensive tillage and reduced tillage). We hypothesized that cover cropping effects increase with decreasing management intensity. Our study demonstrated that cover crop effects on crop yield were highest in the organic system with reduced tillage (+24%), intermediate in the organic system with tillage (+13%) and in the conventional system with no tillage (+8%) and lowest in the conventional system with tillage (+2%). Our results indicate that cover crops are essential to maintaining a certain yield level when soil tillage intensity is reduced (e.g. under conservation agriculture), or when production is converted to organic agriculture. Thus, the inclusion of cover crops provides additional opportunities to increase the yield of lower intensity production systems and contribute to ecological intensification.

  6. Rotational discontinuities and the structure of the magnetopause

    International Nuclear Information System (INIS)

    Swift, D.W.; Lee, L.C.

    1983-01-01

    Symmetric and asymmetric rotational discontinuities are studied by means of a one-dimensional computer simulation and by single-particle trajectory calculations. The numerical simulations show the symmetric rotation to be stable for both ion and electron senses of rotation with a thickness of the order of a few ion gyroradii when the rotation angle of the tangential field is 180 0 or less. Larger rotation angles tend to be unstable. In an expansive discontinuity, when the magnetic field on the downstream side of the discontinuity is larger, an expanding transition layer separating the high-field from a low-field region develops on the downstream side, and a symmetric rotational discontinuity forms at the upstream edge. The implication of these results for magnetopause structure and energy flow through the magnetopause is described

  7. Complete bromate and nitrate reduction using hydrogen as the sole electron donor in a rotating biofilm-electrode reactor

    International Nuclear Information System (INIS)

    Zhong, Yu; Li, Xin; Yang, Qi; Wang, Dongbo; Yao, Fubing; Li, Xiaoming; Zhao, Jianwei; Xu, Qiuxiang; Zhang, Chang; Zeng, Guangming

    2016-01-01

    Graphical abstract: Main mechanism of simultaneous bromate and nitrate removal in the RBER. - Highlights: • Cathode of RBER was designed to automatically rotate. • Simultaneous bromate and nitrate removal was achieved by auto-hydrogenotrophic reduction. • The maximum bromate reduction rate estimated by the Monod equation was 109.12 μg/L h. • An electron transfer process and main reaction mechanism in RBER was explored. - Abstract: Simultaneous reduction of bromate and nitrate was investigated using a rotating biofilm-electrode reactor (RBER) with graphite carbon (GC) rods as anode and activated carbon fiber (ACF) bonded with steel ring as cathode. In RBER, the community of denitrifying bacteria immobilized on the cathode surface could completely utilize hydrogen (H 2 ) as the electron donor, which was internally produced by the electrolysis of water. The short-term test confirmed that the RBER system could reduce 150–800 μg/L bromate to below 10 μg/L under autotrophic conditions. The reduced bromate was considered to be roughly equivalent to the amount of bromide in effluent, indicating that bromate was completely reduced to bromide without accumulation of by-products. The long-term test (over 120 days) showed that the removal fluxes of bromate and nitrate could be improved by increasing the electric current and decreasing the hydraulic retention time (HRT). But nitrite in effluent was significantly accumulated when the electric current was beyond 10 mA and the HRT was less than 6 h. The maximum bromate reduction rate estimated by the Monod equation was 109.12 μg/L h when the electric current was 10 mA and HRT was 12 h. It was proposed that the electron transfer process in RBER produced H 2 on the surface of the ACF cathode, and the microbial cultures attached closely on the cathode which could completely utilize H 2 as electron donors for reduction of bromate and nitrate.

  8. Complete bromate and nitrate reduction using hydrogen as the sole electron donor in a rotating biofilm-electrode reactor

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yu; Li, Xin [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Yang, Qi, E-mail: yangqi@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Wang, Dongbo [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Advanced Water Management Centre, The University of Queensland, QLD 4072 (Australia); Yao, Fubing [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Li, Xiaoming, E-mail: xmli@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Zhao, Jianwei; Xu, Qiuxiang; Zhang, Chang; Zeng, Guangming [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China)

    2016-04-15

    Graphical abstract: Main mechanism of simultaneous bromate and nitrate removal in the RBER. - Highlights: • Cathode of RBER was designed to automatically rotate. • Simultaneous bromate and nitrate removal was achieved by auto-hydrogenotrophic reduction. • The maximum bromate reduction rate estimated by the Monod equation was 109.12 μg/L h. • An electron transfer process and main reaction mechanism in RBER was explored. - Abstract: Simultaneous reduction of bromate and nitrate was investigated using a rotating biofilm-electrode reactor (RBER) with graphite carbon (GC) rods as anode and activated carbon fiber (ACF) bonded with steel ring as cathode. In RBER, the community of denitrifying bacteria immobilized on the cathode surface could completely utilize hydrogen (H{sub 2}) as the electron donor, which was internally produced by the electrolysis of water. The short-term test confirmed that the RBER system could reduce 150–800 μg/L bromate to below 10 μg/L under autotrophic conditions. The reduced bromate was considered to be roughly equivalent to the amount of bromide in effluent, indicating that bromate was completely reduced to bromide without accumulation of by-products. The long-term test (over 120 days) showed that the removal fluxes of bromate and nitrate could be improved by increasing the electric current and decreasing the hydraulic retention time (HRT). But nitrite in effluent was significantly accumulated when the electric current was beyond 10 mA and the HRT was less than 6 h. The maximum bromate reduction rate estimated by the Monod equation was 109.12 μg/L h when the electric current was 10 mA and HRT was 12 h. It was proposed that the electron transfer process in RBER produced H{sub 2} on the surface of the ACF cathode, and the microbial cultures attached closely on the cathode which could completely utilize H{sub 2} as electron donors for reduction of bromate and nitrate.

  9. Trade-offs between economic and environmental impacts of introducing legumes into cropping systems

    Directory of Open Access Journals (Sweden)

    Moritz eReckling

    2016-05-01

    Full Text Available Europe’s agriculture is highly specialized, dependent on external inputs and responsible for negative environmental impacts. Legume crops are grown on less than 2 % of the arable land and more than 70 % of the demand for protein feed supplement is imported from overseas. The integration of legumes into cropping systems has the potential to contribute to the transition to a more resource-efficient agriculture and reduce the current protein deficit. Legume crops influence the production of other crops in the rotation making it difficult to evaluate the overall agronomic effects of legumes in cropping systems. A novel assessment framework was developed and applied in five case study regions across Europe with the objective of evaluating trade-offs between economic and environmental effects of integrating legumes into cropping systems. Legumes resulted in positive and negative impacts when integrated into various cropping systems across the case studies. On average, cropping systems with legumes reduced nitrous oxide emissions by 18 % and 33 % and N fertilizer use by 24 % and 38 % in arable and forage systems, respectively, compared to systems without legumes. Nitrate leaching was similar with and without legumes in arable systems and reduced by 22 % in forage systems. However, grain legumes reduced gross margins in 3 of 5 regions. Forage legumes increased gross margins in 3 of 3 regions. Among the cropping systems with legumes, systems could be identified that had both relatively high economic returns and positive environmental impacts. Thus, increasing the cultivation of legumes could lead to economic competitive cropping systems and positive environmental impacts, but achieving this aim requires the development of novel management strategies informed by the involvement of advisors and farmers.

  10. FCDD: A Database for Fruit Crops Diseases.

    Science.gov (United States)

    Chauhan, Rupal; Jasrai, Yogesh; Pandya, Himanshu; Chaudhari, Suman; Samota, Chand Mal

    2014-01-01

    Fruit Crops Diseases Database (FCDD) requires a number of biotechnology and bioinformatics tools. The FCDD is a unique bioinformatics resource that compiles information about 162 details on fruit crops diseases, diseases type, its causal organism, images, symptoms and their control. The FCDD contains 171 phytochemicals from 25 fruits, their 2D images and their 20 possible sequences. This information has been manually extracted and manually verified from numerous sources, including other electronic databases, textbooks and scientific journals. FCDD is fully searchable and supports extensive text search. The main focus of the FCDD is on providing possible information of fruit crops diseases, which will help in discovery of potential drugs from one of the common bioresource-fruits. The database was developed using MySQL. The database interface is developed in PHP, HTML and JAVA. FCDD is freely available. http://www.fruitcropsdd.com/

  11. CONTRIBUTIONS TO THE DEVELOPMENT OF THE FIELD CROPS YIELD IN TEISANI AREA HOUSEHOLDS, PRAHOVA COUNTY

    Directory of Open Access Journals (Sweden)

    Cristina Elena ANGELESCU

    2015-06-01

    Full Text Available The aim of the paper was to analyze the technological performance of the field crops on luvisoils in Teisani area, Prahova County, where corn and potato are cultivated for personal consumption and beet for animal nutrition. The cultivation of wheat and fodder plants has been an exception. Studies conducted have firstly referred to the introduction of crops in rotation system, through cooperation and exchange between households and within their own household for those with larger surfaces. To compare the productivity of crops, the yield energy value has been used as a measure unit, which facilitates the comparison. The yields was reduced up to the lower limit of crop potential because of monocultures and the lack of appropriate technologies, even for small farming machinery. The results showed that using improved technologies, in 2013 and 2014, the yields were significantly superior, the highest ones, for potatoes and alfalfa, the last one as jumper field. Introducing alfalfa in the crop rotation system has led to the potato yield doubling, but also of those of wheat, corn and beet. Using manure and organic material available and degradable in the form of compost made in their own household, to which are added small amounts of nitrogen and phosphorus, there were obtained average yields by 40% higher than the average of the experience and by 139%, i.e. 2.4 times higher than the unfertilized variant, very much used in the area. Therefore, it was demonstrated, that there are huge resources to produce agricultural products and primary food in the Teisani rural area. Small peasant households should be encouraged and financially supported to participate to food production both for their own consumption, but also for the market.

  12. Faraday rotation in the M87 radio/X-ray halo

    Science.gov (United States)

    Dennison, B.

    1980-01-01

    Comparison of polarization maps at various wavelengths demonstrates the existence of a large Faraday rotation uniform over the radio core of M87. Much of this rotation must be external to the core, lest it appear completely depolarized when the rotation is about 90 degrees. The Faraday rotation is shown to occur primarily in the surrounding radio/X-ray halo. Using the electron density inferred from X-ray observations, the magnetic field in the halo is found to be 2.5 microgauss. The deduced magnetic field strength permits an evaluation of the importance of Compton scattering of 3 K background photons by relativistic electrons in the radio halo. The emergent Compton-scattered spectrum is calculated, and its contribution to the observed X-ray flux is small, probably about a percent or so, while the rest is due to thermal bremsstrahlung.

  13. Production of Short-Rotation Woody Crops Grown with a Range of Nutrient and Water Availability: Establishment Report and First-Year Responses

    Energy Technology Data Exchange (ETDEWEB)

    D.R. Coyle; J. Blake; K. Britton; M.; R.G. Campbell; J. Cox; B. Cregg; D. Daniels; M. Jacobson; K. Johnsen; T. McDonald; K. McLeod; E.; D. Robison; R. Rummer; F. Sanchez; J.; B. Stokes; C. Trettin; J. Tuskan; L. Wright; S. Wullschleger

    2003-12-31

    Coleman, M.D., et. al. 2003. Production of Short-Rotation Woody Crops Grown with a Range of Nutrient and Water Availability: Establishment Report and First-Year Responses. Report. USDA Forest Service, Savannah River, Aiken, SC. 26 pp. Abstract: Many researchers have studied the productivity potential of intensively managed forest plantations. However, we need to learn more about the effects of fundamental growth processes on forest productivity; especially the influence of aboveground and belowground resource acquisition and allocation. This report presents installation, establishment, and first-year results of four tree species (two cottonwood clones, sycamore, sweetgum, and loblolly pine) grown with fertilizer and irrigation treatments. At this early stage of development, irrigation and fertilization were additive only in cottonwood clone ST66 and sweetgum. Leaf area development was directly related to stem growth, but root production was not always consistent with shoot responses, suggesting that allocation of resources varies among treatments. We will evaluate the consequences of these early responses on resource availability in subsequent growing seasons. This information will be used to: (1) optimize fiber and bioenergy production; (2) understand carbon sequestration; and (3) develop innovative applications such as phytoremediation; municipal, industrial, and agricultural wastes management; and protection of soil, air, and water resources.

  14. Multi-model uncertainty analysis in predicting grain N for crop rotations in Europe

    Czech Academy of Sciences Publication Activity Database

    Yin, X.; Kersebaum, K. C.; Kollas, C.; Baby, S.; Beaudoin, N.; Manevski, K.; Palosuo, T.; Nendel, C.; Wu, L.; Hoffmann, M.; Hoffmann, H. D.; Sharif, B.; Armas-Herrera, C.; Bindi, M.; Charfeddine, M.; Conradt, T.; Constantin, J.; Ewert, F.; Ferrise, R.; Gaiser, T.; de Cortazar-Atauri, I. G.; Giglio, L.; Hlavinka, Petr; Lana, M.; Launay, M.; Louarn, G.; Manderscheid, R.; Mary, B.; Mirschel, W.; Moriondo, M.; Oeztuerk, M.; Pacholski, A.; Ripoche-Wachter, D.; Roetter, R. P.; Ruget, F.; Trnka, Miroslav; Ventrella, D.; Weigel, H-J.; Olesen, J. E.

    2017-01-01

    Roč. 84, mar (2017), s. 152-165 ISSN 1161-0301 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : air co2 enrichment * climate-change * catch crops * nitrogen-fertilization * wheat production * winter-wheat * model stics * sugar-beet * wide-range * growth * Continuous simulation * Grain N * Model calibration * Model ensemble * Model inter-comparison * Single year simulation Subject RIV: GC - Agronomy OBOR OECD: Agronomy , plant breeding and plant protection Impact factor: 3.757, year: 2016

  15. Rendimento de soja em sistema de integração lavoura-pecuária: efeito de métodos e intensidades de pastejo Soybean yield in an animal-crop rotation