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Sample records for affect crop yields

  1. Topsoil Depth Effects on Crop Yields as Affected by Weather

    NASA Astrophysics Data System (ADS)

    Lee, Scott; Cruse, Richard

    2015-04-01

    Topsoil (A-horizon) depth is positively correlated with crop productivity; crop roots and available nutrients are concentrated in this layer; topsoil is critical for nutrient retention and water holding capacity. Its loss or reduction can be considered an irreversible impact of soil erosion. Climatic factors such as precipitation and temperature extremes that impose production stress further complicate the relationship between soil erosion and crop productivity. The primary research objective was to determine the effects of soil erosion on corn and soybean yields of loess and till-derived soils in the rain-fed farming region of Iowa. Data collection took place from 2007 to 2012 at seven farm sites located in different major soil regions. Collection consisted of 40 to 50 randomly selected georeferenced soil probe locations across varying erosion classes in well drained landscape positions. Soil probes were done to a minimum depth of 100 cm and soil organic carbon samples were obtained in the top 10 cm. Crop yields were determined utilizing georeferenced harvest maps from yield monitoring devices and cross referenced with georeferenced field data points. Data analysis targeted relationships between crop yields versus soil organic carbon contents (SOC) and crop yields versus topsoil depths (TSD). The variation of yield and growing season rainfall across multiple years were also evaluated to provide an indication of soil resiliency associated with topsoil depth and soil organic carbon levels across varying climatic conditions. Results varied between sites but generally indicated a greater yield potential at thicker TSD's and higher SOC concentrations; an annual variation in yield response as a function of precipitation amount during the growing season; largest yield responses to both TSD and SOC occurred in the driest study year (2012); and little to no significant yield responses to TSD occurred during the wettest study year (2010). These results were not

  2. Growth and yield of winter wheat as affected by preceding crop and crop management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers in eastern South Dakota are interested in adding winter wheat (Triticum aestivum L.) to the corn (Zea mays L.)-soybean (Glycine max Merrill) rotation to improve crop yield and pest management. Our study quantified winter wheat response to preceding crop and crop management. Preceding cro...

  3. Dryland soil chemical properties and crop yields affected by long-term tillage and cropping sequence.

    PubMed

    Sainju, Upendra M; Allen, Brett L; Caesar-TonThat, Thecan; Lenssen, Andrew W

    2015-01-01

    Information on the effect of long-term management on soil nutrients and chemical properties is scanty. We examined the 30-year effect of tillage frequency and cropping sequence combination on dryland soil Olsen-P, K, Ca, Mg, Na, SO4-S, and Zn concentrations, pH, electrical conductivity (EC), and cation exchange capacity (CEC) at the 0-120 cm depth and annualized crop yield in the northern Great Plains, USA. Treatments were no-till continuous spring wheat (Triticum aestivum L.) (NTCW), spring till continuous spring wheat (STCW), fall and spring till continuous spring wheat (FSTCW), fall and spring till spring wheat-barley (Hordeum vulgare L., 1984-1999) followed by spring wheat-pea (Pisum sativum L., 2000-2013) (FSTW-B/P), and spring till spring wheat-fallow (STW-F, traditional system). At 0-7.5 cm, P, K, Zn, Na, and CEC were 23-60% were greater, but pH, buffer pH, and Ca were 6-31% lower in NTCW, STCW, and FSTW-B/P than STW-F. At 7.5-15 cm, K was 23-52% greater, but pH, buffer pH, and Mg were 3-21% lower in NTCW, STCW, FSTCW, FSTW-B/P than STW-F. At 60-120 cm, soil chemical properties varied with treatments. Annualized crop yield was 23-30% lower in STW-F than the other treatments. Continuous N fertilization probably reduced soil pH, Ca, and Mg, but greater crop residue returned to the soil increased P, K, Na, Zn, and CEC in NTCW and STCW compared to STW-F. Reduced tillage with continuous cropping may be adopted for maintaining long-term soil fertility and crop yields compared with the traditional system. PMID:26171303

  4. Soil Carbon and Nitrogen Fractions and Crop Yields Affected by Residue Placement and Crop Types

    PubMed Central

    Wang, Jun; Sainju, Upendra M.

    2014-01-01

    Soil labile C and N fractions can change rapidly in response to management practices compared to non-labile fractions. High variability in soil properties in the field, however, results in nonresponse to management practices on these parameters. We evaluated the effects of residue placement (surface application [or simulated no-tillage] and incorporation into the soil [or simulated conventional tillage]) and crop types (spring wheat [Triticum aestivum L.], pea [Pisum sativum L.], and fallow) on crop yields and soil C and N fractions at the 0–20 cm depth within a crop growing season in the greenhouse and the field. Soil C and N fractions were soil organic C (SOC), total N (STN), particulate organic C and N (POC and PON), microbial biomass C and N (MBC and MBN), potential C and N mineralization (PCM and PNM), NH4-N, and NO3-N concentrations. Yields of both wheat and pea varied with residue placement in the greenhouse as well as in the field. In the greenhouse, SOC, PCM, STN, MBN, and NH4-N concentrations were greater in surface placement than incorporation of residue and greater under wheat than pea or fallow. In the field, MBN and NH4-N concentrations were greater in no-tillage than conventional tillage, but the trend reversed for NO3-N. The PNM was greater under pea or fallow than wheat in the greenhouse and the field. Average SOC, POC, MBC, PON, PNM, MBN, and NO3-N concentrations across treatments were higher, but STN, PCM and NH4-N concentrations were lower in the greenhouse than the field. The coefficient of variation for soil parameters ranged from 2.6 to 15.9% in the greenhouse and 8.0 to 36.7% in the field. Although crop yields varied, most soil C and N fractions were greater in surface placement than incorporation of residue and greater under wheat than pea or fallow in the greenhouse than the field within a crop growing season. Short-term management effect on soil C and N fractions were readily obtained with reduced variability under controlled soil and

  5. Soil carbon and nitrogen fractions and crop yields affected by residue placement and crop types.

    PubMed

    Wang, Jun; Sainju, Upendra M

    2014-01-01

    Soil labile C and N fractions can change rapidly in response to management practices compared to non-labile fractions. High variability in soil properties in the field, however, results in nonresponse to management practices on these parameters. We evaluated the effects of residue placement (surface application [or simulated no-tillage] and incorporation into the soil [or simulated conventional tillage]) and crop types (spring wheat [Triticum aestivum L.], pea [Pisum sativum L.], and fallow) on crop yields and soil C and N fractions at the 0-20 cm depth within a crop growing season in the greenhouse and the field. Soil C and N fractions were soil organic C (SOC), total N (STN), particulate organic C and N (POC and PON), microbial biomass C and N (MBC and MBN), potential C and N mineralization (PCM and PNM), NH4-N, and NO3-N concentrations. Yields of both wheat and pea varied with residue placement in the greenhouse as well as in the field. In the greenhouse, SOC, PCM, STN, MBN, and NH4-N concentrations were greater in surface placement than incorporation of residue and greater under wheat than pea or fallow. In the field, MBN and NH4-N concentrations were greater in no-tillage than conventional tillage, but the trend reversed for NO3-N. The PNM was greater under pea or fallow than wheat in the greenhouse and the field. Average SOC, POC, MBC, PON, PNM, MBN, and NO3-N concentrations across treatments were higher, but STN, PCM and NH4-N concentrations were lower in the greenhouse than the field. The coefficient of variation for soil parameters ranged from 2.6 to 15.9% in the greenhouse and 8.0 to 36.7% in the field. Although crop yields varied, most soil C and N fractions were greater in surface placement than incorporation of residue and greater under wheat than pea or fallow in the greenhouse than the field within a crop growing season. Short-term management effect on soil C and N fractions were readily obtained with reduced variability under controlled soil and

  6. Cover crops can affect subsequent wheat yield in the central great plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop production systems in the water-limited environment of the semi-arid central Great Plains may not have potential to profitably use cover crops because of lowered subsequent wheat (Triticum asestivum L.) yields following the cover crop. Cover crop mixtures have reportedly shown less yield-reduci...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  8. Greenhouse tomato limited cluster production systems: crop management practices affect yield

    NASA Technical Reports Server (NTRS)

    Logendra, L. S.; Gianfagna, T. J.; Specca, D. R.; Janes, H. W.

    2001-01-01

    Limited-cluster production systems may be a useful strategy to increase crop production and profitability for the greenhouse tomato (Lycopersicon esculentum Mill). In this study, using an ebb-and-flood hydroponics system, we modified plant architecture and spacing and determined the effects on fruit yield and harvest index at two light levels. Single-cluster plants pruned to allow two leaves above the cluster had 25% higher fruit yields than did plants pruned directly above the cluster; this was due to an increase in fruit weight, not fruit number. Both fruit yield and harvest index were greater for all single-cluster plants at the higher light level because of increases in both fruit weight and fruit number. Fruit yield for two-cluster plants was 30% to 40% higher than for single-cluster plants, and there was little difference in the dates or length of the harvest period. Fruit yield for three-cluster plants was not significantly different from that of two-cluster plants; moreover, the harvest period was delayed by 5 days. Plant density (5.5, 7.4, 9.2 plants/m2) affected fruit yield/plant, but not fruit yield/unit area. Given the higher costs for materials and labor associated with higher plant densities, a two-cluster crop at 5.5 plants/m2 with two leaves above the cluster was the best of the production system strategies tested.

  9. Dryland soil chemical properties and crop yields affected by long-term tillage and cropping sequence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information on the effect of long-term management on soil nutrients and chemical properties is scanty. We examined the 30-yr effect of tillage frequency and cropping sequence combination on dryland soil Olsen-P, K, Ca, Mg, Na, SO4-S, and Zn concentrations, pH, electrical conductivity (EC), and catio...

  10. Dryland malt barley yield and quality affected by tillage, cropping sequence, and nitrogen fertilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information is needed on the effects of management practices on dryland malt barley (Hordeum vulgaris L.) and pea (Pisum sativum L.) yields and quality. We evaluated the effects of tillage and cropping sequence combination and N fertilization on dryland malt barley and pea yields, grain characterist...

  11. Variability of soil properties and crop yield in landscapes affected by long-term tillage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intensive tillage moves large quantities of soil, resulting in a pattern of soil redistribution where topsoil is depleted from convex slope positions and deposited in concave positions. In these experiments, the variation in erosion estimates, soil properties and crop yield were determined in a hill...

  12. Crop rotation affects corn, grain sorghum, and soybean yields and nitrogen recovery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term cropping system and fertilizer N studies are essential towards understanding production potential and yield stability of corn (Zea mays L.), grain sorghum [Sorghum bicolor (L.) Moench], and soybean [Glycine max (L.) Merr.] in rain-fed environments. A no-till experiment (2007-13) was conduc...

  13. Residue and soil carbon sequestration in relation to crop yield as affected by irrigation, tillage, cropping system and nitrogen fertilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. Herbicide and cover crop residue integration affects on weed control, quality, and yield in conservation tillage tomato

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The increased use of conservation tillage in vegetable production requires more information be developed on the role of cover crops in weed control, tomato quality and yield. Three conservation-tillage systems utilizing crimson clover, brassica and cereal rye as winter cover crops were compared to ...

  15. Decomposing global crop yield variability

    NASA Astrophysics Data System (ADS)

    Ben-Ari, Tamara; Makowski, David

    2014-11-01

    Recent food crises have highlighted the need to better understand the between-year variability of agricultural production. Although increasing future production seems necessary, the globalization of commodity markets suggests that the food system would also benefit from enhanced supplies stability through a reduction in the year-to-year variability. Here, we develop an analytical expression decomposing global crop yield interannual variability into three informative components that quantify how evenly are croplands distributed in the world, the proportion of cultivated areas allocated to regions of above or below average variability and the covariation between yields in distinct world regions. This decomposition is used to identify drivers of interannual yield variations for four major crops (i.e., maize, rice, soybean and wheat) over the period 1961-2012. We show that maize production is fairly spread but marked by one prominent region with high levels of crop yield interannual variability (which encompasses the North American corn belt in the USA, and Canada). In contrast, global rice yields have a small variability because, although spatially concentrated, much of the production is located in regions of below-average variability (i.e., South, Eastern and South Eastern Asia). Because of these contrasted land use allocations, an even cultivated land distribution across regions would reduce global maize yield variance, but increase the variance of global yield rice. Intermediate results are obtained for soybean and wheat for which croplands are mainly located in regions with close-to-average variability. At the scale of large world regions, we find that covariances of regional yields have a negligible contribution to global yield variance. The proposed decomposition could be applied at any spatial and time scales, including the yearly time step. By addressing global crop production stability (or lack thereof) our results contribute to the understanding of a key

  16. Possible future directions in crop yield forecasting

    NASA Technical Reports Server (NTRS)

    Colwell, J. E.

    1979-01-01

    This paper examines present and future possible applications of remote sensing to crop yield forecasting. It is concluded that there are ways in which Landsat data could be used to assist in crop yield forecasting using present technology. A framework for global crop yield forecasting which uses remote sensing, meteorological, field and ancillary data, as available, is proposed for the future.

  17. Linking Drought Information to Crop Yield

    NASA Astrophysics Data System (ADS)

    Madadgar, S.; Farahmand, A.; Li, L.; Aghakouchak, A.

    2015-12-01

    Droughts have detrimental impacts on agricultural yields all over the world every year. This study analyzes the relationship between three drought indicators including Standardized Precipitation Index (SPI); Standardized Soil Moisture Index (SSI), Multivariate Standardized Drought Index (MSDI) and the yields of five largest rain-fed crops in Australia (wheat, broad beans, canola, lupins and barley). Variation of the five chosen crop yields is overall in agreement with the three drought indicators SPI, SSI, and MSDI during the analysis period of 1980-2012. This study develops a bivariate copula model to investigate the statistical dependence of drought and crop yield. Copula functions are used to establish the existing connections between climate variables and crop yields during the Millennium drought in Australia. The proposed model estimates the likelihood of crop yields given the observed or predicted drought indicators SPI, SSI or MSDI. The results are also useful to estimate crop yields associated with different thresholds of precipitation or soil moisture.

  18. Effects of geoengineering on crop yields

    NASA Astrophysics Data System (ADS)

    Pongratz, J.; Lobell, D. B.; Cao, L.; Caldeira, K.

    2011-12-01

    market shares of agricultural output may change with the different spatial pattern of climate change. More importantly, geoengineering by SRM does not address a range of other detrimental consequences of climate change, such as ocean acidification, which could also affect food security via effects on marine food webs. Finally, SRM poses substantial anticipated and unanticipated risks by interfering with complex, not fully understood systems. Therefore, despite potential positive effects of SRM on crop yields, the most certain way to reduce climate risks to global food security is to reduce emissions of greenhouse gases.

  19. Cover crops and tillage in a mature Merlot vineyard affect yields and cluster weight but not nutrition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Permanent cover crops are commonly used in vineyard floor management because of their beneficial effects to soil and vine health, but studies evaluating their competitive effects on vines have been conducted primarily in non-irrigated vineyards. Future air quality regulations could mandate the use o...

  20. Crop status evaluations and yield predictions

    NASA Technical Reports Server (NTRS)

    Haun, J. R.

    1976-01-01

    One phase of the large area crop inventory project is presented. Wheat yield models based on the input of environmental variables potentially obtainable through the use of space remote sensing were developed and demonstrated. By the use of a unique method for visually qualifying daily plant development and subsequent multifactor computer analyses, it was possible to develop practical models for predicting crop development and yield. Development of wheat yield prediction models was based on the discovery that morphological changes in plants are detected and quantified on a daily basis, and that this change during a portion of the season was proportional to yield.

  1. Potential use of MODIS imagery for operational crop yield assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monitoring crop condition and yields at regional scales remains a challenge. Ground-based sampling for assessment of crop yields at regional and national scales require enormous resources. Crop yield simulation models have shown great success in predicting crop yields at field and small scales; how...

  2. Global crop yield losses from recent warming

    SciTech Connect

    Lobell, D; Field, C

    2006-06-02

    Global yields of the world-s six most widely grown crops--wheat, rice, maize, soybeans, barley, sorghum--have increased since 1961. Year-to-year variations in growing season minimum temperature, maximum temperature, and precipitation explain 30% or more of the variations in yield. Since 1991, climate trends have significantly decreased yield trends in all crops but rice, leading to foregone production since 1981 of about 12 million tons per year of wheat or maize, representing an annual economic loss of $1.2 to $1.7 billion. At the global scale, negative impacts of climate trends on crop yields are already apparent. Annual global temperatures have increased by {approx}0.4 C since 1980, with even larger changes observed in several regions (1). While many studies have considered the impacts of future climate changes on food production (2-5), the effects of these past changes on agriculture remain unclear. It is likely that warming has improved yields in some areas, reduced them in others, and had negligible impacts in still others; the relative balance of these effects at the global scale is unknown. An understanding of this balance would help to anticipate impacts of future climate changes, as well as to more accurately assess recent (and thereby project future) technologically driven yield progress. Separating the contribution of climate from concurrent changes in other factors--such as crop cultivars, management practices, soil quality, and atmospheric carbon dioxide (CO{sub 2}) levels--requires models that describe the response of yields to climate. Studies of future global impacts of climate change have typically relied on a bottom-up approach, whereby field scale, process-based models are applied to hundreds of representative sites and then averaged (e.g., ref 2). Such approaches require input data on soil and management conditions, which are often difficult to obtain. Limitations on data quality or quantity can thus limit the utility of this approach

  3. Airborne hyperspectral imagery for mapping crop yield variability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information concerning the spatial variation in crop yield has become necessary for site-specific crop management. Traditional satellite imagery has long been used to monitor crop growing conditions and to estimate crop yields over large geographic areas. However, this type of imagery has limited us...

  4. Yield and Economic Responses of Peanut to Crop Rotation Sequence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proper crop rotation is essential to maintaining high peanut yield and quality. However, the economic considerations of maintaining or altering crop rotation sequences must incorporate the commodity prices, production costs, and yield responses of all crops in, or potentially in, the crop rotation ...

  5. Crop status evaluations and yield predictions

    NASA Technical Reports Server (NTRS)

    Haun, J. R.

    1975-01-01

    A model was developed for predicting the day 50 percent of the wheat crop is planted in North Dakota. This model incorporates location as an independent variable. The Julian date when 50 percent of the crop was planted for the nine divisions of North Dakota for seven years was regressed on the 49 variables through the step-down multiple regression procedure. This procedure begins with all of the independent variables and sequentially removes variables that are below a predetermined level of significance after each step. The prediction equation was tested on daily data. The accuracy of the model is considered satisfactory for finding the historic dates on which to initiate yield prediction model. Growth prediction models were also developed for spring wheat.

  6. Second Generation Crop Yield Models Review

    NASA Technical Reports Server (NTRS)

    Hodges, T. (Principal Investigator)

    1982-01-01

    Second generation yield models, including crop growth simulation models and plant process models, may be suitable for large area crop yield forecasting in the yield model development project. Subjective and objective criteria for model selection are defined and models which might be selected are reviewed. Models may be selected to provide submodels as input to other models; for further development and testing; or for immediate testing as forecasting tools. A plant process model may range in complexity from several dozen submodels simulating (1) energy, carbohydrates, and minerals; (2) change in biomass of various organs; and (3) initiation and development of plant organs, to a few submodels simulating key physiological processes. The most complex models cannot be used directly in large area forecasting but may provide submodels which can be simplified for inclusion into simpler plant process models. Both published and unpublished models which may be used for development or testing are reviewed. Several other models, currently under development, may become available at a later date.

  7. Bats and birds increase crop yield in tropical agroforestry landscapes.

    PubMed

    Maas, Bea; Clough, Yann; Tscharntke, Teja

    2013-12-01

    Human welfare is significantly linked to ecosystem services such as the suppression of pest insects by birds and bats. However, effects of biocontrol services on tropical cash crop yield are still largely unknown. For the first time, we manipulated the access of birds and bats in an exclosure experiment (day, night and full exclosures compared to open controls in Indonesian cacao agroforestry) and quantified the arthropod communities, the fruit development and the final yield over a long time period (15 months). We found that bat and bird exclusion increased insect herbivore abundance, despite the concurrent release of mesopredators such as ants and spiders, and negatively affected fruit development, with final crop yield decreasing by 31% across local (shade cover) and landscape (distance to primary forest) gradients. Our results highlight the tremendous economic impact of common insectivorous birds and bats, which need to become an essential part of sustainable landscape management. PMID:24131776

  8. Soil Moisture as an Estimator for Crop Yield in Germany

    NASA Astrophysics Data System (ADS)

    Peichl, Michael; Meyer, Volker; Samaniego, Luis; Thober, Stephan

    2015-04-01

    , phenological, geological, agronomic, and socio-economic variables are also considered to extend the model in order to reveal the proper causal relation. First results show that dry as well as wet extremes of SMI have a negative impact on crop yield for winter wheat. This indicates that soil moisture has at least a limiting affect on crop production.

  9. Cover crops can improve potato tuber yield and quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is the need to develop sustainable systems with higher yields and crop quality. We conducted studies with cover crops grown under limited irrigation (< 200 mm) to assess the effects of certain types of cover crops on tuber yield and quality. On a commercial farm operation prior to the 2006 and...

  10. Educational Software for Illustration of Drainage, Evapotranspiration, and Crop Yield.

    ERIC Educational Resources Information Center

    Khan, A. H.; And Others

    1996-01-01

    Describes a study that developed a software package for illustrating drainage, evapotranspiration, and crop yield as influenced by water conditions. The software is a tool for depicting water's influence on crop production in western Kansas. (DDR)

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

    PubMed Central

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

    2000-01-01

    Belonolaimus longicaudatus has been reported as damaging both potato (Solanum tuberosum) and cotton (Gossypium hirsutum). These crops are not normally grown in cropping systems together in areas where the soil is infested with B. longicaudatus. During the 1990s cotton was grown in a potato production region that was a suitable habitat for B. longicaudatus. It was not known how integrating the production of these two crops by rotation or double-cropping would affect the population densities of B. longicaudatus, other plant-parasitic nematodes common in the region, or crop yields. A 3-year field study evaluated the viability of both crops in monocropping, rotation, and double-cropping systems. Viability was evaluated using effects on population densities of plant-parasitic nematodes and yields. Rotation of cotton with potato was found to decrease population densities of B. longicaudatus and Meloidogyne incognita in comparison with continuous potato. Population densities of B. longicaudatus following double-cropping were greater than following continuous cotton. Yields of both potato and cotton in rotation were equivalent to either crop in monocropping. Yields of both crops were lower following double-cropping when nematicides were not used. PMID:19270980

  12. Weather-based forecasts of California crop yields

    SciTech Connect

    Lobell, D B; Cahill, K N; Field, C B

    2005-09-26

    Crop yield forecasts provide useful information to a range of users. Yields for several crops in California are currently forecast based on field surveys and farmer interviews, while for many crops official forecasts do not exist. As broad-scale crop yields are largely dependent on weather, measurements from existing meteorological stations have the potential to provide a reliable, timely, and cost-effective means to anticipate crop yields. We developed weather-based models of state-wide yields for 12 major California crops (wine grapes, lettuce, almonds, strawberries, table grapes, hay, oranges, cotton, tomatoes, walnuts, avocados, and pistachios), and tested their accuracy using cross-validation over the 1980-2003 period. Many crops were forecast with high accuracy, as judged by the percent of yield variation explained by the forecast, the number of yields with correctly predicted direction of yield change, or the number of yields with correctly predicted extreme yields. The most successfully modeled crop was almonds, with 81% of yield variance captured by the forecast. Predictions for most crops relied on weather measurements well before harvest time, allowing for lead times that were longer than existing procedures in many cases.

  13. Modeling temporal and spatial variability of crop yield

    NASA Astrophysics Data System (ADS)

    Bonetti, S.; Manoli, G.; Scudiero, E.; Morari, F.; Putti, M.; Teatini, P.

    2014-12-01

    In a world of increasing food insecurity the development of modeling tools capable of supporting on-farm decision making processes is highly needed to formulate sustainable irrigation practices in order to preserve water resources while maintaining adequate crop yield. The design of these practices starts from the accurate modeling of soil-plant-atmosphere interaction. We present an innovative 3D Soil-Plant model that couples 3D hydrological soil dynamics with a mechanistic description of plant transpiration and photosynthesis, including a crop growth module. Because of its intrinsically three dimensional nature, the model is able to capture spatial and temporal patterns of crop yield over large scales and under various climate and environmental factors. The model is applied to a 25 ha corn field in the Venice coastland, Italy, that has been continuously monitored over the years 2010 and 2012 in terms of both hydrological dynamics and yield mapping. The model results satisfactorily reproduce the large variability observed in maize yield (from 2 to 15 ton/ha). This variability is shown to be connected to the spatial heterogeneities of the farmland, which is characterized by several sandy paleo-channels crossing organic-rich silty soils. Salt contamination of soils and groundwater in a large portion of the area strongly affects the crop yield, especially outside the paleo-channels, where measured salt concentrations are lower than the surroundings. The developed model includes a simplified description of the effects of salt concentration in soil water on transpiration. The results seem to capture accurately the effects of salt concentration and the variability of the climatic conditions occurred during the three years of measurements. This innovative modeling framework paves the way to future large scale simulations of farmland dynamics.

  14. Ecoinformatics Reveals Effects of Crop Rotational Histories on Cotton Yield

    PubMed Central

    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. PMID:24465657

  15. Increasing Crop Diversity Mitigates Weather Variations and Improves Yield Stability

    PubMed Central

    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

  16. Climate variation explains a third of global crop yield variability

    PubMed Central

    Ray, Deepak K.; Gerber, James S.; MacDonald, Graham K.; West, Paul C.

    2015-01-01

    Many studies have examined the role of mean climate change in agriculture, but an understanding of the influence of inter-annual climate variations on crop yields in different regions remains elusive. We use detailed crop statistics time series for ~13,500 political units to examine how recent climate variability led to variations in maize, rice, wheat and soybean crop yields worldwide. While some areas show no significant influence of climate variability, in substantial areas of the global breadbaskets, >60% of the yield variability can be explained by climate variability. Globally, climate variability accounts for roughly a third (~32–39%) of the observed yield variability. Our study uniquely illustrates spatial patterns in the relationship between climate variability and crop yield variability, highlighting where variations in temperature, precipitation or their interaction explain yield variability. We discuss key drivers for the observed variations to target further research and policy interventions geared towards buffering future crop production from climate variability. PMID:25609225

  17. The Importance of Juvenile Root Traits for Crop Yields

    NASA Astrophysics Data System (ADS)

    White, Philip; Adu, Michael; Broadley, Martin; Brown, Lawrie; Dupuy, Lionel; George, Timothy; Graham, Neil; Hammond, John; Hayden, Rory; Neugebauer, Konrad; Nightingale, Mark; Ramsay, Gavin; Thomas, Catherine; Thompson, Jacqueline; Wishart, Jane; Wright, Gladys

    2014-05-01

    Genetic variation in root system architecture (RSA) is an under-exploited breeding resource. This is partly a consequence of difficulties in the rapid and accurate assessment of subterranean root systems. However, although the characterisation of root systems of large plants in the field are both time-consuming and labour-intensive, high-throughput (HTP) screens of root systems of juvenile plants can be performed in the field, glasshouse or laboratory. It is hypothesised that improving the root systems of juvenile plants can accelerate access to water and essential mineral elements, leading to rapid crop establishment and, consequently, greater yields. This presentation will illustrate how aspects of the juvenile root systems of potato (Solanum tuberosum L.) and oilseed rape (OSR; Brassica napus L.) correlate with crop yields and examine the reasons for such correlations. It will first describe the significant positive relationships between early root system development, phosphorus acquisition, canopy establishment and eventual yield among potato genotypes. It will report the development of a glasshouse assay for root system architecture (RSA) of juvenile potato plants, the correlations between root system architectures measured in the glasshouse and field, and the relationships between aspects of the juvenile root system and crop yields under drought conditions. It will then describe the development of HTP systems for assaying RSA of OSR seedlings, the identification of genetic loci affecting RSA in OSR, the development of mathematical models describing resource acquisition by OSR, and the correlations between root traits recorded in the HTP systems and yields of OSR in the field.

  18. A quality assessment of the MARS crop yield forecasting system for the European Union

    NASA Astrophysics Data System (ADS)

    van der Velde, Marijn; Bareuth, Bettina

    2015-04-01

    Timely information on crop production forecasts can become of increasing importance as commodity markets are more and more interconnected. Impacts across large crop production areas due to (e.g.) extreme weather and pest outbreaks can create ripple effects that may affect food prices and availability elsewhere. The MARS Unit (Monitoring Agricultural ResourceS), DG Joint Research Centre, European Commission, has been providing forecasts of European crop production levels since 1993. The operational crop production forecasting is carried out with the MARS Crop Yield Forecasting System (M-CYFS). The M-CYFS is used to monitor crop growth development, evaluate short-term effects of anomalous meteorological events, and provide monthly forecasts of crop yield at national and European Union level. The crop production forecasts are published in the so-called MARS bulletins. Forecasting crop yield over large areas in the operational context requires quality benchmarks. Here we present an analysis of the accuracy and skill of past crop yield forecasts of the main crops (e.g. soft wheat, grain maize), throughout the growing season, and specifically for the final forecast before harvest. Two simple benchmarks to assess the skill of the forecasts were defined as comparing the forecasts to 1) a forecast equal to the average yield and 2) a forecast using a linear trend established through the crop yield time-series. These reveal a variability in performance as a function of crop and Member State. In terms of production, the yield forecasts of 67% of the EU-28 soft wheat production and 80% of the EU-28 maize production have been forecast superior to both benchmarks during the 1993-2013 period. In a changing and increasingly variable climate crop yield forecasts can become increasingly valuable - provided they are used wisely. We end our presentation by discussing research activities that could contribute to this goal.

  19. Impacts of the Future Changes in Extreme Events on the Regional Crop Yield in Turkey

    NASA Astrophysics Data System (ADS)

    An, Nazan; Turp, M. Tufan; Ozturk, Tugba; Kurnaz, M. Levent

    2016-04-01

    The changes in extreme events caused by climate change have the greatest impact on agricultural sector specifically crop yield. Therefore, it requires a clear understanding of how extreme events affect the crop yield and how it causes high economic losses. In this research, we cover the relationship between extreme events and the crop yield in Turkey for the period of 2020 - 2045 with respect to 1980 - 2005. We focus on the role of those extreme event causing natural disasters on the regional crop yield. This research comprises 2 parts. In the first part, the projection is performed according to the business as usual scenario of IPCC, RCP8.5, via the RegCM4.4 in order to obtain extreme event indices required for the crop assessment. In the second part, the crop yield and the extreme event indices are combined by applying the econometric analysis in order to see the relationship between natural disasters and crop yield. The risks for crop yield caused by the extreme events are estimated and interpreted. This study aims to assess the effect of frequency of expected extreme events on the crop yield at the cropland of Turkey. This research has been supported by Boǧaziçi University Research Fund Grant Number 10421.

  20. Unsupervised linear unmixing of hyperspectral image for crop yield estimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multispectral and hyperspectral imagery are often used for estimating crop yield. This paper describes an unsupervised unmixing scheme of hyperspectral images to estimate crop yield. From the hyperspectral images, the endmembers and their abundance maps are computed by unsupervised unmixing. The abu...

  1. Hyperspectral imagery for mapping crop yield for precision agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop yield is perhaps the most important piece of information for crop management in precision agriculture. It integrates the effects of various spatial variables such as soil properties, topographic attributes, tillage, plant population, fertilization, irrigation, and pest infestations. A yield map...

  2. Random Forests for Global and Regional Crop Yield Predictions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traditional regression models have limitations when applied for predicting crop yield responses at multiple spatial scales. An alternative modeling method, Random Forest (RF) regression, was utilized to predict crop yield responses for wheat, maize, and potato at regional scales. This RF regressio...

  3. YIELD EDITOR: SOFTWARE FOR REMOVING ERRORS FROM CROP YIELD MAPS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yield maps are a key component of precision agriculture, due to their usefulness in both development and evaluation of precision management strategies. The value of these yield maps can be compromised by the fact that raw yield maps contain a variety of inherent errors. Researchers have reported t...

  4. Cropping frequency and area response to climate variability can exceed yield response

    NASA Astrophysics Data System (ADS)

    Cohn, Avery S.; Vanwey, Leah K.; Spera, Stephanie A.; Mustard, John F.

    2016-06-01

    The sensitivity of agricultural output to climate change has often been estimated by modelling crop yields under climate change scenarios or with statistical analysis of the impacts of year-to-year climatic variability on crop yields. However, the area of cropland and the number of crops harvested per growing season (cropping frequency) both also affect agricultural output and both also show sensitivity to climate variability and change. We model the change in agricultural output associated with the response of crop yield, crop frequency and crop area to year-to-year climate variability in Mato Grosso (MT), Brazil, a key agricultural region. Roughly 70% of the change in agricultural output caused by climate was determined by changes in frequency and/or changes in area. Hot and wet conditions were associated with the largest losses and cool and dry conditions with the largest gains. All frequency and area effects had the same sign as total effects, but this was not always the case for yield effects. A focus on yields alone may therefore bias assessments of the vulnerability of agriculture to climate change. Efforts to reduce climate impacts to agriculture should seek to limit production losses not only from crop yield, but also from changes in cropland area and cropping frequency.

  5. Tropical Rotation Crops Influence Nematode Densities and Vegetable Yields

    PubMed Central

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

    1994-01-01

    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 ≤ 0.05) following sorghum-sudangrass than after any of the other treatments except fallow. Yield of eggplant was greater (P ≤ 0.05) following castor, sesame, or American jointvetch than following okra or fallow. Several of the rotation crops evaluated here may be useful for managing nematodes in the field and for improving yields of subsequent vegetable crops. PMID:19279897

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

    PubMed

    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 Yield of eggplant was greater (P crops evaluated here may be useful for managing nematodes in the field and for improving yields of subsequent vegetable crops. PMID:19279897

  7. Scheduling for deficit irrigation, Crop Yield Predictor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigators in many countries with dwindling water supplies face the prospect that they will not be able to fully irrigate their crops. In these cases, they still need to schedule their water applications to make the best economic use of available water. Major scheduling questions for deficit irrigat...

  8. Mapping Crop Yield and Sow Date Using High Resolution Imagery

    NASA Astrophysics Data System (ADS)

    Royal, K.

    2015-12-01

    Keitasha Royal, Meha Jain, Ph.D., David Lobell, Ph.D Mapping Crop Yield and Sow Date Using High Resolution ImageryThe use of satellite imagery in agriculture is becoming increasingly more significant and valuable. Due to the emergence of new satellites, such as Skybox, these satellites provide higher resolution imagery (e.g 1m) therefore improving the ability to map smallholder agriculture. For the smallholder farm dominated area of northern India, Skybox high-resolution satellite imagery can aid in understanding how to improve farm yields. In particular, we are interested in mapping winter wheat in India, as this region produces approximately 80% of the country's wheat crop, which is important given that wheat is a staple crop that provides approximately 20% of household calories. In northeast India, the combination of increased heat stress, limited irrigation access, and the difficulty for farmers to access advanced farming technologies results in farmers only producing about 50% of their potential crop yield. The use of satellite imagery can aid in understanding wheat yields through time and help identify ways to increase crop yields in the wheat belt of India. To translate Skybox satellite data into meaningful information about wheat fields, we examine vegetation indices, such as the normalized difference vegetation index (NDVI), to measure the "greenness" of plants to help determine the health of the crops. We test our ability to predict crop characteristics, like sow date and yield, using vegetation indices of 59 fields for which we have field data in Bihar, India.

  9. The impact of Global Warming on global crop yields due to changes in pest pressure

    NASA Astrophysics Data System (ADS)

    Battisti, D. S.; Tewksbury, J. J.; Deutsch, C. A.

    2011-12-01

    A billion people currently lack reliable access to sufficient food and almost half of the calories feeding these people come from just three crops: rice, maize, wheat. Insect pests are among the largest factors affecting the yield of these three crops, but models assessing the effects of global warming on crops rarely consider changes in insect pest pressure on crop yields. We use well-established relationships between temperature and insect physiology to project climate-driven changes in pest pressure, defined as integrated population metabolism, for the three major crops. By the middle of this century, under most scenarios, insect pest pressure is projected to increase by more than 50% in temperate areas, while increases in tropical regions will be more modest. Yield relationships indicate that the largest increases in insect pest pressure are likely to occur in areas where yield is greatest, suggesting increased strain on global food markets.

  10. Random Forests for Global and Regional Crop Yield Predictions

    PubMed Central

    Jeong, Jig Han; Resop, Jonathan P.; Mueller, Nathaniel D.; Fleisher, David H.; Yun, Kyungdahm; Butler, Ethan E.; Timlin, Dennis J.; Shim, Kyo-Moon; Gerber, James S.; Reddy, Vangimalla R.

    2016-01-01

    Accurate predictions of crop yield are critical for developing effective agricultural and food policies at the regional and global scales. We evaluated a machine-learning method, Random Forests (RF), for its ability to predict crop yield responses to climate and biophysical variables at global and regional scales in wheat, maize, and potato in comparison with multiple linear regressions (MLR) serving as a benchmark. We used crop yield data from various sources and regions for model training and testing: 1) gridded global wheat grain yield, 2) maize grain yield from US counties over thirty years, and 3) potato tuber and maize silage yield from the northeastern seaboard region. RF was found highly capable of predicting crop yields and outperformed MLR benchmarks in all performance statistics that were compared. For example, the root mean square errors (RMSE) ranged between 6 and 14% of the average observed yield with RF models in all test cases whereas these values ranged from 14% to 49% for MLR models. Our results show that RF is an effective and versatile machine-learning method for crop yield predictions at regional and global scales for its high accuracy and precision, ease of use, and utility in data analysis. RF may result in a loss of accuracy when predicting the extreme ends or responses beyond the boundaries of the training data. PMID:27257967

  11. Direct effects of rising atmospheric carbon dioxide on crop yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rising atmospheric carbon dioxide concentration (CO2) in this century will alter crop yield quantity and quality. It is important to understand the magnitude of the expected changes and the mechanisms involved in crop responses to elevated CO2 in order to adapt our food systems to the committed chan...

  12. Incorporating remote sensing data in crop model to monitor crop growth and predict yield in regional area

    NASA Astrophysics Data System (ADS)

    Guo, Jianmao; Lu, Weisong; Zhang, Guoping; Qian, Yonglan; Yu, Qiang; Zhang, Jiahua

    2006-12-01

    Accurate crop growth monitoring and yield predicting is very important to food security and agricultural sustainable development. Crop models can be forceful tools for monitoring crop growth status and predicting yield over homogeneous areas, however, their application to a larger spatial domains is hampered by lack of sufficient spatial information about model inputs, such as the value of some of their parameters and initial conditions, which may have great difference between regions even fields. The use of remote sensing data helps to overcome this problem. By incorporating remote sensing data into the WOFOST crop model (through LAI), it is possible to incorporate remote sensing variables (vegetation index) for each point of the spatial domain, and it is possible for this point to re-estimate new values of the parameters or initial conditions, to which the model is particularly sensitive. This paper describes the use of such a method on a local scale, for winter wheat, focusing on the parameters describing emergence and early crop growth. These processes vary greatly depending on the soil, climate and seedbed preparation, and affect yield significantly. The WOFOST crop model is calibrated under standard conditions and then evaluated under test conditions to which the emergence and early growth parameters of the WOFOST model are adjusted by incorporating remote sensing data. The inversion of the combined model allows us to accurately monitoring crop growth status and predicting yield on a regional scale.

  13. Are the yields of major cereal crops stagnating? Results from the newly developed high spatial resolution crop yield time series

    NASA Astrophysics Data System (ADS)

    Ray, D. K.; Ramankutty, N.; Foley, J. A.

    2011-12-01

    A variety of global scale studies that use crop yield time series for the last 50 years have remained constrained to using national level information due to the lack of high spatial resolution crop yield time series data. In this presentation we will unveil a new global crop yield data set for the 1961-2008 time period, at 5 min spatial resolution, and covering 174 crops. We developed this data by collecting national and sub-national harvested area and production information for individual crops. This new dataset can be used to answer questions related to global agriculture at a resolution and over a time period not previously possible. We have used this new dataset to address the question of whether the yields of the three important cereal crops -- maize, rice and wheat -- are stagnating as widely reported. Our results show that while in the older crop belts of the world yield improvements have slowed, a green revolution type of major yield increases in maize, rice and wheat are continuing in newly cultivated areas of the world.

  14. Quantifying the US Crop Yield in Response to Extreme Climatic Events from 1948 to 2013

    NASA Astrophysics Data System (ADS)

    Jin, Z.; Zhuang, Q.

    2014-12-01

    The increasingly frequent and severe extreme climatic events (ECEs) under climate changes will negatively affect crop productivity and threat the global food security. Reliable forecast of crop yields response to those ECEs is a prerequisite for developing strategies on agricultural risk management. However, the progress of quantifying such responses with ecosystem models has been slow. In this study, we first review existing algorithms of yields response to ECEs among major crops (i.e., Corn, Wheat and Soybean) for the United States from a set of process-based crop models. These algorithms are aggregated into four categories of ECEs: drought, heavy precipitation, extreme heat, and frost. Species-specific ECEs thresholds as tipping point of crop yield response curve are examined. Four constraint scalar functions derived for each category of ECEs are then added to an agricultural ecosystem model, CLM-AG, respectively. The revised model is driven by NCEP/NCAR reanalysis data from 1948 to 2013 to estimate the US major crop yields, and then evaluated with county-level yield statistics from the National Agricultural Statistics Service (NASS). We also include MODIS NPP product as a reference for the period 2001-2013. Our study will help to identify gaps in capturing yield response to ECEs with contemporary crop models, and provide a guide on developing the new generation of crop models to account for the effects of more future extreme climate events.

  15. Estimating soil moisture and the relationship with crop yield using surface temperature and vegetation index

    NASA Astrophysics Data System (ADS)

    Holzman, M. E.; Rivas, R.; Piccolo, M. C.

    2014-05-01

    Soil moisture availability affects rainfed crop yield. Therefore, the development of methods for pre-harvest yield prediction is essential for the food security. A study was carried out to estimate regional crop yield using the Temperature Vegetation Dryness Index (TVDI). Triangular scatters from land surface temperature (LST) and enhanced vegetation index (EVI) space from MODIS (Moderate Resolution Imaging Spectroradiometer) were utilized to obtain TVDI and to estimate soil moisture availability. Then soybean and wheat crops yield was estimated on four agro-climatic zones of Argentine Pampas. TVDI showed a strong correlation with soil moisture measurements, with R2 values ranged from 0.61 to 0.83 and also it was in agreement with spatial pattern of soil moisture. Moreover, results showed that TVDI data can be used effectively to predict crop yield on the Argentine Pampas. Depending on the agro-climatic zone, R2 values ranged from 0.68 to 0.79 for soybean crop and 0.76 to 0.81 for wheat. The RMSE values were 366 and 380 kg ha-1 for soybean and they varied between 300 and 550 kg ha-1 in the case of wheat crop. When expressed as percentages of actual yield, the RMSE values ranged from 12% to 13% for soybean and 14% to 22% for wheat. The bias values indicated that the obtained models underestimated soybean and wheat yield. Accurate crop grain yield forecast using the developed regression models was achieved one to three months before harvest. In many cases the results were better than others obtained using only a vegetation index, showing the aptitude of surface temperature and vegetation index combination to reflect the crop water condition. Finally, the analysis of a wide range of soil moisture availability allowed us to develop a generalized model of crop yield and dryness index relationship which could be applicable in other regions and crops at regional scale.

  16. Enhancing crop yield by optimizing plant developmental features.

    PubMed

    Mathan, Jyotirmaya; Bhattacharya, Juhi; Ranjan, Aashish

    2016-09-15

    A number of plant features and traits, such as overall plant architecture, leaf structure and morphological features, vascular architecture and flowering time are important determinants of photosynthetic efficiency and hence the overall performance of crop plants. The optimization of such developmental traits thus has great potential to increase biomass and crop yield. Here, we provide a comprehensive review of these developmental traits in crop plants, summarizing their genetic regulation and highlighting the potential of manipulating these traits for crop improvement. We also briefly review the effects of domestication on the developmental features of crop plants. Finally, we discuss the potential of functional genomics-based approaches to optimize plant developmental traits to increase yield. PMID:27624833

  17. Climate change impacts on crop yield: evidence from China.

    PubMed

    Wei, Taoyuan; Cherry, Todd L; Glomrød, Solveig; Zhang, Tianyi

    2014-11-15

    When estimating climate change impact on crop yield, a typical assumption is constant elasticity of yield with respect to a climate variable even though the elasticity may be inconstant. After estimating both constant and inconstant elasticities with respect to temperature and precipitation based on provincial panel data in China 1980-2008, our results show that during that period, the temperature change contributes positively to total yield growth by 1.3% and 0.4% for wheat and rice, respectively, but negatively by 12% for maize. The impacts of precipitation change are marginal. We also compare our estimates with other studies and highlight the implications of the inconstant elasticities for crop yield, harvest and food security. We conclude that climate change impact on crop yield would not be an issue in China if positive impacts of other socio-economic factors continue in the future. PMID:25181045

  18. Large Area Crop Inventory Experiment (LACIE). Feasibility of assessing crop condition and yield from LANDSAT data

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The author has identified the following significant results. Yield modelling for crop production estimation derived a means of predicting the within-a-year yield and the year-to-year variability of yield over some fixed or randomly located unit of area. Preliminary studies indicated that the requirements for interpreting LANDSAT data for yield may be sufficiently similar to those of signature extension that it is feasible to investigate the automated estimation of production. The concept of an advanced yield model consisting of both spectral and meteorological components was endorsed. Rationale for using meteorological parameters originated from known between season and near harvest dynamics in crop environmental-condition-yield relationships.

  19. Effects of simulated sulfuric acid rain on yield, growth, and foliar injury of several crops

    SciTech Connect

    Lee, J.J.; Neely, G.E.; Perrigan, S.C.; Grothaus, L.C.

    1980-10-01

    This study was designed to reveal patterns of response of major United States crops to sulfuric acid rain. Potted plants were grown in field chambers and exposed to simulated sulfuric acid rain (pH 3.0, 3.5 or 4.0) or to a control rain (pH 5.6). At harvest, the weights of the marketable portion, total aboveground portion and roots were determined for 28 crops. Of these, marketable yield production was inhibited for 5 crops (radish, beet, carrot, mustard greens, broccoli), stimulated for 6 crops (tomato, green pepper, strawberry, alfalfa, orchardgrass, timothy), and ambiguously affected for 1 crop (potato). In addition, stem and leaf production of sweet corn was stimulated. Visible injury of tomatoes might have decreased their marketability. No statistically significant effects on yield were observed for the other 15 crops. The results suggest that the likelihood of yield being affected by acid rain depends on the part of the plant utilized, as well as on species. Effects on the aboveground portions of crops and on roots are also presented. Plants were regularly examined for foliar injury associated with acid rain. Of the 35 cultivars examined, the foliage of 31 was injured at pH 3.0, 28 at pH 3.5, and 5 at pH 4.0. Foliar injury was not generally related to effects on yield. However, foilar injury of swiss chard, mustard greens and spinach was severe enough to adversely affect marketability.

  20. The Impact of Climate and Its Variability on Crop Yield and Irrigation

    NASA Astrophysics Data System (ADS)

    Li, X.; Troy, T.

    2014-12-01

    As the global population grows and the climate changes, having a secure food supply is increasingly important especially under water stressed-conditions. Although irrigation is a positive climate adaptation mechanism for agriculture, it has a potentially negative effect on water resources. It is therefore important to understand how crop yields due to irrigation are affected by climate variability and how irrigation may buffer against climate, allowing for more resilient agricultural systems. Efforts to solve these barely exposed questions can benefit from comprehending the influence of climate variability on crop yield and irrigation water use in the past. To do this, we use historical climate data,irrigation water use data and rainfed and irrigated crop yields over the US to analyze the relationship among climate, irrigation and delta crop yields, gained by subtracting rainfed yield from irrigated yield since 1970. We find that the increase in delta crop yield due to irrigation is larger for certain climate conditions, such that there are optimal climate conditions where irrigation provides a benefit and other conditions where irrigation proves to have marginal benefits when temperature increased to certain degrees. We find that crop water requirements are linked to potential evapotranspiration, yet actual irrigation water use is largely decoupled from the climate conditions but related with other causes. This has important implications for agricultural and water resource system planning, as it implies there are optimal climate zones where irrigation is productive and that changes in water use, both temporally and spatially, could lead to increased water availability without negative impacts on crop yields. Furthermore, based on the exposed relationship between crop yield gained by irrigation and climate variability, those models predicting the global harvest will be redress to estimate crop production in the future more accurately.

  1. Possible changes to arable crop yields by 2050.

    PubMed

    Jaggard, Keith W; Qi, Aiming; Ober, Eric S

    2010-09-27

    By 2050, the world population is likely to be 9.1 billion, the CO(2) concentration 550 ppm, the ozone concentration 60 ppb and the climate warmer by ca 2 degrees C. In these conditions, what contribution can increased crop yield make to feeding the world? CO(2) enrichment is likely to increase yields of most crops by approximately 13 per cent but leave yields of C4 crops unchanged. It will tend to reduce water consumption by all crops, but this effect will be approximately cancelled out by the effect of the increased temperature on evaporation rates. In many places increased temperature will provide opportunities to manipulate agronomy to improve crop performance. Ozone concentration increases will decrease yields by 5 per cent or more. Plant breeders will probably be able to increase yields considerably in the CO(2)-enriched environment of the future, and most weeds and airborne pests and diseases should remain controllable, so long as policy changes do not remove too many types of crop-protection chemicals. However, soil-borne pathogens are likely to be an increasing problem when warmer weather will increase their multiplication rates; control is likely to need a transgenic approach to breeding for resistance. There is a large gap between achievable yields and those delivered by farmers, even in the most efficient agricultural systems. A gap is inevitable, but there are large differences between farmers, even between those who have used the same resources. If this gap is closed and accompanied by improvements in potential yields then there is a good prospect that crop production will increase by approximately 50 per cent or more by 2050 without extra land. However, the demands for land to produce bio-energy have not been factored into these calculations. PMID:20713388

  2. Possible changes to arable crop yields by 2050

    PubMed Central

    Jaggard, Keith W.; Qi, Aiming; Ober, Eric S.

    2010-01-01

    By 2050, the world population is likely to be 9.1 billion, the CO2 concentration 550 ppm, the ozone concentration 60 ppb and the climate warmer by ca 2°C. In these conditions, what contribution can increased crop yield make to feeding the world? CO2 enrichment is likely to increase yields of most crops by approximately 13 per cent but leave yields of C4 crops unchanged. It will tend to reduce water consumption by all crops, but this effect will be approximately cancelled out by the effect of the increased temperature on evaporation rates. In many places increased temperature will provide opportunities to manipulate agronomy to improve crop performance. Ozone concentration increases will decrease yields by 5 per cent or more. Plant breeders will probably be able to increase yields considerably in the CO2-enriched environment of the future, and most weeds and airborne pests and diseases should remain controllable, so long as policy changes do not remove too many types of crop-protection chemicals. However, soil-borne pathogens are likely to be an increasing problem when warmer weather will increase their multiplication rates; control is likely to need a transgenic approach to breeding for resistance. There is a large gap between achievable yields and those delivered by farmers, even in the most efficient agricultural systems. A gap is inevitable, but there are large differences between farmers, even between those who have used the same resources. If this gap is closed and accompanied by improvements in potential yields then there is a good prospect that crop production will increase by approximately 50 per cent or more by 2050 without extra land. However, the demands for land to produce bio-energy have not been factored into these calculations. PMID:20713388

  3. Linear unmixing of multidate hyperspectral imagery for crop yield estimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this paper, we have evaluated an unsupervised unmixing approach, vertex component analysis (VCA), for the application of crop yield estimation. The results show that abundance maps of the vegetation extracted by the approach are strongly correlated to the yield data (the correlation coefficients ...

  4. Evaluating SPOT 5 Multispectral Imagery for Crop Yield Estimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High resolution satellite imagery has the potential for mapping within-field variability in crop growth and yield. This study examined SPOT 5 multispectral imagery for estimating grain sorghum yield. A SPOT 5 image with 10-m spatial resolution and four spectral bands (green, red, near-infrared and m...

  5. Surprising yields with no-till cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers using no-till practices have observed that crop yields can greatly exceed expectations based on nutrient and water supply. For example, Ralph Holzwarth, who farms near Gettysburg, SD, has averaged 150 bu/ac of corn on his farm for the past 6 years. We were surprised with this yield, as c...

  6. Surprising yields with no-till cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers using no-till systems have found that crop yields often exceed their expectation based on nutrient and water supply. For example, corn yields 7% higher in a no-till system in central South Dakota than in a tilled system in eastern South Dakota. This is surprising because rainfall is 5 in...

  7. Preventing pesticide contamination of groundwater while maximizing irrigated crop yield

    NASA Astrophysics Data System (ADS)

    Peralta, R. C.; Hegazy, M. A.; Musharrafieh, G. R.

    1994-11-01

    A simulation/optimization model is developed for maximizing irrigated crop yield while avoiding unacceptable pesticide leaching. The optimization model is designed to help managers prevent non-point source contamination of shallow groundwater aquifers. It computes optimal irrigation amounts for given soil, crop, chemical, and weather data and irrigation frequencies. It directly computes the minimum irrigated crop yield reduction needed to prevent groundwater contamination. Constraint equations used in the model maintain a layered soil moisture volume balance; describe percolation, downward unsaturated zone solute transport and pesticide degradation; and limit the amount of pesticide reaching groundwater. Constraints are linear, piecewise linear, nonlinear, and exponential. The problem is solved using nonlinear programming optimization. The model is tested for different scenarios of irrigating corn. The modeling approach is promising as a tool to aid in the development of environmentally sound agricultural production practices. It allows direct estimation of trade-offs between crop production and groundwater protection for different management approaches. More frequent irrigation tends to give better crop yield and reduce solute movement. Trade-offs decrease with increasing irrigation frequency. More frequent irrigation reduces yield loss due to moisture stress and requires less water to fill the root zone to field capacity. This prevents the solute from moving to deeper soil layers. Yield-environmental quality trade-offs are smaller for deeper groundwater tables because deeper groundwater allows more time for chemical degradation.

  8. Nut crop yield records show that budbreak-based chilling requirements may not reflect yield decline chill thresholds.

    PubMed

    Pope, Katherine S; Dose, Volker; Da Silva, David; Brown, Patrick H; DeJong, Theodore M

    2015-06-01

    Warming winters due to climate change may critically affect temperate tree species. Insufficiently cold winters are thought to result in fewer viable flower buds and the subsequent development of fewer fruits or nuts, decreasing the yield of an orchard or fecundity of a species. The best existing approximation for a threshold of sufficient cold accumulation, the "chilling requirement" of a species or variety, has been quantified by manipulating or modeling the conditions that result in dormant bud breaking. However, the physiological processes that affect budbreak are not the same as those that determine yield. This study sought to test whether budbreak-based chilling thresholds can reasonably approximate the thresholds that affect yield, particularly regarding the potential impacts of climate change on temperate tree crop yields. County-wide yield records for almond (Prunus dulcis), pistachio (Pistacia vera), and walnut (Juglans regia) in the Central Valley of California were compared with 50 years of weather records. Bayesian nonparametric function estimation was used to model yield potentials at varying amounts of chill accumulation. In almonds, average yields occurred when chill accumulation was close to the budbreak-based chilling requirement. However, in the other two crops, pistachios and walnuts, the best previous estimate of the budbreak-based chilling requirements was 19-32 % higher than the chilling accumulations associated with average or above average yields. This research indicates that physiological processes beyond requirements for budbreak should be considered when estimating chill accumulation thresholds of yield decline and potential impacts of climate change. PMID:25119825

  9. Nut crop yield records show that budbreak-based chilling requirements may not reflect yield decline chill thresholds

    NASA Astrophysics Data System (ADS)

    Pope, Katherine S.; Dose, Volker; Da Silva, David; Brown, Patrick H.; DeJong, Theodore M.

    2015-06-01

    Warming winters due to climate change may critically affect temperate tree species. Insufficiently cold winters are thought to result in fewer viable flower buds and the subsequent development of fewer fruits or nuts, decreasing the yield of an orchard or fecundity of a species. The best existing approximation for a threshold of sufficient cold accumulation, the "chilling requirement" of a species or variety, has been quantified by manipulating or modeling the conditions that result in dormant bud breaking. However, the physiological processes that affect budbreak are not the same as those that determine yield. This study sought to test whether budbreak-based chilling thresholds can reasonably approximate the thresholds that affect yield, particularly regarding the potential impacts of climate change on temperate tree crop yields. County-wide yield records for almond ( Prunus dulcis), pistachio ( Pistacia vera), and walnut ( Juglans regia) in the Central Valley of California were compared with 50 years of weather records. Bayesian nonparametric function estimation was used to model yield potentials at varying amounts of chill accumulation. In almonds, average yields occurred when chill accumulation was close to the budbreak-based chilling requirement. However, in the other two crops, pistachios and walnuts, the best previous estimate of the budbreak-based chilling requirements was 19-32 % higher than the chilling accumulations associated with average or above average yields. This research indicates that physiological processes beyond requirements for budbreak should be considered when estimating chill accumulation thresholds of yield decline and potential impacts of climate change.

  10. Developing robust crop plants for sustaining growth and yield under adverse climatic changes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural production and quality are expected to suffer from adverse changes in climatic conditions, including global warming, and this will affect worldwide human and animal food security. Global warming has been shown to negatively impact crop yield and therefore will affect sustainability of a...

  11. Climate Variability and Yields of Major Staple Food Crops in Northern Ghana

    NASA Astrophysics Data System (ADS)

    Amikuzuno, J.

    2012-12-01

    Climate variability, the short-term fluctuations in average weather conditions, and agriculture affect each other. Climate variability affects the agroecological and growing conditions of crops and livestock, and is recently believed to be the greatest impediment to the realisation of the first Millennium Development Goal of reducing poverty and food insecurity in arid and semi-arid regions of developing countries. Conversely, agriculture is a major contributor to climate variability and change by emitting greenhouse gases and reducing the agroecology's potential for carbon sequestration. What however, is the empirical evidence of this inter-dependence of climate variability and agriculture in Sub-Sahara Africa? In this paper, we provide some insight into the long run relationship between inter-annual variations in temperature and rainfall, and annual yields of the most important staple food crops in Northern Ghana. Applying pooled panel data of rainfall, temperature and yields of the selected crops from 1976 to 2010 to cointegration and Granger causality models, there is cogent evidence of cointegration between seasonal, total rainfall and crop yields; and causality from rainfall to crop yields in the Sudano-Guinea Savannah and Guinea Savannah zones of Northern Ghana. This suggests that inter-annual yields of the crops have been influenced by the total mounts of rainfall in the planting season. Temperature variability over the study period is however stationary, and is suspected to have minimal effect if any on crop yields. Overall, the results confirm the appropriateness of our attempt in modelling long-term relationships between the climate and crop yield variables.

  12. Impacts of El Nino Southern Oscillation on the Global Yields of Major Crops

    NASA Technical Reports Server (NTRS)

    Iizumi, Toshichika; Luo, Jing-Jia; Challinor, Andrew J.; Sakurai, Gen; Yokozawa, Masayuki; Sakuma, Hirofumi; Brown, Molly Elizabeth; Yamagata, Toshio

    2014-01-01

    The monitoring and prediction of climate-induced variations in crop yields, production and export prices in major food-producing regions have become important to enable national governments in import-dependent countries to ensure supplies of affordable food for consumers. Although the El Nino/Southern Oscillation (ENSO) often affects seasonal temperature and precipitation, and thus crop yields in many regions, the overall impacts of ENSO on global yields are uncertain. Here we present a global map of the impacts of ENSO on the yields of major crops and quantify its impacts on their global-mean yield anomalies. Results show that El Nino likely improves the global-mean soybean yield by 2.15.4 but appears to change the yields of maize, rice and wheat by -4.3 to +0.8. The global-mean yields of all four crops during La Nina years tend to be below normal (-4.5 to 0.0).Our findings highlight the importance of ENSO to global crop production.

  13. Impacts of El Niño Southern Oscillation on the global yields of major crops.

    PubMed

    Iizumi, Toshichika; Luo, Jing-Jia; Challinor, Andrew J; Sakurai, Gen; Yokozawa, Masayuki; Sakuma, Hirofumi; Brown, Molly E; Yamagata, Toshio

    2014-01-01

    The monitoring and prediction of climate-induced variations in crop yields, production and export prices in major food-producing regions have become important to enable national governments in import-dependent countries to ensure supplies of affordable food for consumers. Although the El Niño/Southern Oscillation (ENSO) often affects seasonal temperature and precipitation, and thus crop yields in many regions, the overall impacts of ENSO on global yields are uncertain. Here we present a global map of the impacts of ENSO on the yields of major crops and quantify its impacts on their global-mean yield anomalies. Results show that El Niño likely improves the global-mean soybean yield by 2.1-5.4% but appears to change the yields of maize, rice and wheat by -4.3 to +0.8%. The global-mean yields of all four crops during La Niña years tend to be below normal (-4.5 to 0.0%). Our findings highlight the importance of ENSO to global crop production. PMID:24827075

  14. Predicting Crop Yield from Biophysical and Spectral Variables

    NASA Astrophysics Data System (ADS)

    Kancheva, Rumiana; Borisova, Denitsa

    A strong stress is being put over the past years on the application and added-value of remotely sensed data. Agricultural monitoring is an important application field of remote sensing tech-nologies associated with plant growth assessment, stress detection and yield forecasting. In-terest is rapidly spreading in the use of hyperspectral data to precision farming. For precision agriculture running, regular and timely information is needed about plant growth in order to assess crop development and predict yield. Entering wider into their opperational stage, re-mote sensing technologies face higher requirements to the accuracy of the information they provide. Because of the raising need for reliability of the information products, ground-based observations are considered one of the pillars of remote sensing being used in land cover stud-ies for the development and validation of data analysis and retrieval algorithms. This paper presents the results of ground-level studies aimed at the empirical modelling of cereals yield using multispectral and multitemporal data. The objective of the study is to develop and test the performance of vegetation indices as predictors of crop production. The approach com-prises the development of yield forecasting models from single and multi-date spectral data and the verification of remote sensing predictions through comparison with estimations from yield relationships with crop agronomical parameters. Statistical relationships between crop spectral reflectance, growth variables and yield have been established. Grain yield has been related to spectral data acquired at different phenological stages of plant development and to spectral data accumulated during the entire growing season. Comparison has been made between the yield prediction results from crop biophysical, multispectral and multitemporal data in order to validate the predictive performance of the spectral models. The algorithm has been realized on winter wheat. In-situ high

  15. County-Level Crop Yield Prediction Using Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Wagstaff, K. L.; Roper, A.; Lane, T.

    2007-12-01

    Early estimates of crop yield, particularly at a fine scale, can inform precision agriculture efforts. The USDA National Agricultural Statistics Service (NASS) currently provides estimates of yield on a monthly basis for each state. These estimates are based on phone interviews with farmers and in-situ examination of randomly selected plots. We seek to provide predictions at a much higher spatial resolution, on a more frequent basis, using remote sensing observations. We use publicly available data from the MODIS (Moderate Resolution Imaging Spectroradiometer) instruments on the Aqua and Terra spacecraft. These observations have a spatial resolution of 250 m and consist of two spectral bands (red and infra-red) with a repeat period of 8 days. As part of the HARVIST (Heterogeneous Agricultural Research Via Interactive, Scalable Technology) project, we have created statistical crop yield models using historical MODIS data combined with the per-county yield reported by the USDA at the end of the growing season. In our approach, we analyze 100 randomly selected historical pixels from each county to generate a yield prediction for the county as a whole. We construct a time series for each pixel that consists of its NDVI (Normalized Difference Vegetation Index) value observed during each 8-day time period to date. We then cluster all pixels together to identify groups of distinct elements (different crops, bodies of water, urban areas, desert, etc.) and create a regression model for each one. For each crop of interest, the model that best predicts that crop's historical yield is selected. These models can then be applied to data from subsequent years to generate predictions for the future. We applied this approach to data from California and Kansas for corn and wheat. We found that, in general, the yield prediction error decreased as the harvest time approached. In California, distinctly different models were selected to predict corn and wheat, permitting specialization

  16. Comparison of perimeter trap crop varieties: effects on herbivory, pollination, and yield in butternut squash.

    PubMed

    Adler, L S; Hazzard, R V

    2009-02-01

    Perimeter trap cropping (PTC) is a method of integrated pest management (IPM) in which the main crop is surrounded with a perimeter trap crop that is more attractive to pests. Blue Hubbard (Cucurbita maxima Duch.) is a highly effective trap crop for butternut squash (C. moschata Duch. ex Poir) attacked by striped cucumber beetles (Acalymma vittatum Fabricius), but its limited marketability may reduce adoption of PTC by growers. Research comparing border crop varieties is necessary to provide options for growers. Furthermore, pollinators are critical for cucurbit yield, and the effect of PTC on pollination to main crops is unknown. We examined the effect of five border treatments on herbivory, pollination, and yield in butternut squash and manipulated herbivory and pollination to compare their importance for main crop yield. Blue Hubbard, buttercup squash (C. maxima Duch.), and zucchini (C. pepo L.) were equally attractive to cucumber beetles. Border treatments did not affect butternut leaf damage, but butternut flowers had the fewest beetles when surrounded by Blue Hubbard or buttercup squash. Yield was highest in the Blue Hubbard and buttercup treatments, but this effect was not statistically significant. Native bees accounted for 87% of pollinator visits, and pollination did not limit yield. There was no evidence that border crops competed with the main crop for pollinators. Our results suggest that both buttercup squash and zucchini may be viable alternatives to Blue Hubbard as borders for the main crop of butternut squash. Thus, growers may have multiple border options that reduce pesticide use, effectively manage pests, and do not disturb mutualist interactions with pollinators. PMID:19791616

  17. Spectrally-Based Assessment of Crop Seasonal Performance and Yield

    NASA Astrophysics Data System (ADS)

    Kancheva, Rumiana; Borisova, Denitsa; Georgiev, Georgy

    The rapid advances of space technologies concern almost all scientific areas from aeronautics to medicine, and a wide range of application fields from communications to crop yield predictions. Agricultural monitoring is among the priorities of remote sensing observations for getting timely information on crop development. Monitoring agricultural fields during the growing season plays an important role in crop health assessment and stress detection provided that reliable data is obtained. Successfully spreading is the implementation of hyperspectral data to precision farming associated with plant growth and phenology monitoring, physiological state assessment, and yield prediction. In this paper, we investigated various spectral-biophysical relationships derived from in-situ reflectance measurements. The performance of spectral data for the assessment of agricultural crops condition and yield prediction was examined. The approach comprisesd development of regression models between plant spectral and state-indicative variables such as biomass, vegetation cover fraction, leaf area index, etc., and development of yield forecasting models from single-date (growth stage) and multitemporal (seasonal) reflectance data. Verification of spectral predictions was performed through comparison with estimations from biophysical relationships between crop growth variables. The study was carried out for spring barley and winter wheat. Visible and near-infrared reflectance data was acquired through the whole growing season accompanied by detailed datasets on plant phenology and canopy structural and biochemical attributes. Empirical relationships were derived relating crop agronomic variables and yield to various spectral predictors. The study findings were tested using airborne remote sensing inputs. A good correspondence was found between predicted and actual (ground-truth) estimates

  18. Impacts of biofuel cultivation on mortality and crop yields

    NASA Astrophysics Data System (ADS)

    Ashworth, K.; Wild, O.; Hewitt, C. N.

    2013-05-01

    Ground-level ozone is a priority air pollutant, causing ~ 22,000 excess deaths per year in Europe, significant reductions in crop yields and loss of biodiversity. It is produced in the troposphere through photochemical reactions involving oxides of nitrogen (NOx) and volatile organic compounds (VOCs). The biosphere is the main source of VOCs, with an estimated 1,150TgCyr-1 (~ 90% of total VOC emissions) released from vegetation globally. Isoprene (2-methyl-1,3-butadiene) is the most significant biogenic VOC in terms of mass (around 500TgCyr-1) and chemical reactivity and plays an important role in the mediation of ground-level ozone concentrations. Concerns about climate change and energy security are driving an aggressive expansion of bioenergy crop production and many of these plant species emit more isoprene than the traditional crops they are replacing. Here we quantify the increases in isoprene emission rates caused by cultivation of 72Mha of biofuel crops in Europe. We then estimate the resultant changes in ground-level ozone concentrations and the impacts on human mortality and crop yields that these could cause. Our study highlights the need to consider more than simple carbon budgets when considering the cultivation of biofuel feedstock crops for greenhouse-gas mitigation.

  19. Prediction of Potato Crop Yield Using Precision Agriculture Techniques.

    PubMed

    Al-Gaadi, Khalid A; Hassaballa, Abdalhaleem A; Tola, ElKamil; Kayad, Ahmed G; Madugundu, Rangaswamy; Alblewi, Bander; Assiri, Fahad

    2016-01-01

    Crop growth and yield monitoring over agricultural fields is an essential procedure for food security and agricultural economic return prediction. The advances in remote sensing have enhanced the process of monitoring the development of agricultural crops and estimating their yields. Therefore, remote sensing and GIS techniques were employed, in this study, to predict potato tuber crop yield on three 30 ha center pivot irrigated fields in an agricultural scheme located in the Eastern Region of Saudi Arabia. Landsat-8 and Sentinel-2 satellite images were acquired during the potato growth stages and two vegetation indices (the normalized difference vegetation index (NDVI) and the soil adjusted vegetation index (SAVI)) were generated from the images. Vegetation index maps were developed and classified into zones based on vegetation health statements, where the stratified random sampling points were accordingly initiated. Potato yield samples were collected 2-3 days prior to the harvest time and were correlated to the adjacent NDVI and SAVI, where yield prediction algorithms were developed and used to generate prediction yield maps. Results of the study revealed that the difference between predicted yield values and actual ones (prediction error) ranged between 7.9 and 13.5% for Landsat-8 images and between 3.8 and 10.2% for Sentinel-2 images. The relationship between actual and predicted yield values produced R2 values ranging between 0.39 and 0.65 for Landsat-8 images and between 0.47 and 0.65 for Sentinel-2 images. Results of this study revealed a considerable variation in field productivity across the three fields, where high-yield areas produced an average yield of above 40 t ha-1; while, the low-yield areas produced, on the average, less than 21 t ha-1. Identifying such great variation in field productivity will assist farmers and decision makers in managing their practices. PMID:27611577

  20. Remote Sensing and Modeling Methods for Crop Grain Yield Assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monitoring crop condition and yields at regional scales using satellite imagery from operational satellites remains a challenge for the developed and developing countries. Imagery from the MODIS sensor onboard NASA’s TERRA and ACQUA satellites offer an excellent opportunity for daily coverage at 25...

  1. Tillage and Cover Crops Effects on Potato Yield and Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Delayed tillage and the inclusion of cover crops can substantially reduce erosion in intensively tilled potato systems. Both of these practices can potentially impact potato yield and quality via changes in soil temperature and soil water status. Research was conducted over seven rotation cycles a...

  2. Crop yield evaluation under controlled drainage in Ohio, United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drainage water management (NRCS Practice Code 554) is an important agricultural water management practice for reducing nitrate loading to surface water across the Midwest US. There may also be a positive crop yield benefit which could add incentive for adoption of the practice. Results from a three ...

  3. Dynamics of mean-variance-skewness of cumulative crop yield impact temporal yield variance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Production risk associated with cropping systems influences farmers’ decisions to adopt a new management practice or a production system. Cumulative yield (CY), temporal yield variance (TYV) and coefficient of variation (CV) were used to assess the risk associated with adopting combinations of new m...

  4. Modelling Changes to Crop Yield Under Climate Change Scenarios

    NASA Astrophysics Data System (ADS)

    Gerber, J. S.; Deryng, D.; Ray, D. K.; Mueller, N. D.; Foley, J. A.; Ramankutty, N.

    2010-12-01

    This paper presents two sets of quantitative predictions for global soy and maize yields under changes to temperature and precipitation. The climatic changes considered are based on IPCC scenarios A1B and B1 as calculated with a variety of GCMs. One set of crop yield predictions is calculated with the process-based PEGASUS model, the other is based on an empirical climate-analog approach. The core of PEGASUS is a simple global surface energy, water, and carbon balance model. In addition, PEGASUS simulates planting dates and optimum cultivars at different locations of the world, allocates carbon to a grain pool, and uses an empirical relationship to estimate the influence of fertilizer application. In the empirical climate analog approach, recently published global data sets are used to empirically determine maximum attainable (potential) crop yields for a given set of climatic and soil conditions. Farmers are then quantified by their abilities to reach potential yields and as new climatically-limited potential yields obtain under climate change scenarios, farmers’ yields are assumed to evolve proportionally. Preliminary results indicate that global average yields in the future are sensitive to the climate model used to generate the future climate. However, all models indicate a decrease in yields under climate scenarios A1B and B1.

  5. Will current trends close major crop yield gaps by 2025?

    NASA Astrophysics Data System (ADS)

    Ray, D. K.; Mueller, N. D.; Gerber, J. S.; Johnston, M.; Foley, J. A.

    2012-12-01

    Several studies have projected a need to double global agricultural production by 2050 to meet the demands posed by population growth, increased dairy and meat consumption, and biofuel use. However, recent work shows many regions where there are shortfalls in production compared to the regions with the highest yield. While these "yield gaps" could be closed through more intensive and advanced management, already between 24% and 39% of the global crop growing regions are witnessing yield stagnation. In this presentation we will identify the areas across the globe where yield gaps (as quantified circa the year 2000) are projected to either close or persist given observed rates of yield increases. Major investments in better management are needed in areas where yield gaps are projected to persist.

  6. Impact of derived global weather data on simulated crop yields.

    PubMed

    van Wart, Justin; Grassini, Patricio; Cassman, Kenneth G

    2013-12-01

    Crop simulation models can be used to estimate impact of current and future climates on crop yields and food security, but require long-term historical daily weather data to obtain robust simulations. In many regions where crops are grown, daily weather data are not available. Alternatively, gridded weather databases (GWD) with complete terrestrial coverage are available, typically derived from: (i) global circulation computer models; (ii) interpolated weather station data; or (iii) remotely sensed surface data from satellites. The present study's objective is to evaluate capacity of GWDs to simulate crop yield potential (Yp) or water-limited yield potential (Yw), which can serve as benchmarks to assess impact of climate change scenarios on crop productivity and land use change. Three GWDs (CRU, NCEP/DOE, and NASA POWER data) were evaluated for their ability to simulate Yp and Yw of rice in China, USA maize, and wheat in Germany. Simulations of Yp and Yw based on recorded daily data from well-maintained weather stations were taken as the control weather data (CWD). Agreement between simulations of Yp or Yw based on CWD and those based on GWD was poor with the latter having strong bias and large root mean square errors (RMSEs) that were 26-72% of absolute mean yield across locations and years. In contrast, simulated Yp or Yw using observed daily weather data from stations in the NOAA database combined with solar radiation from the NASA-POWER database were in much better agreement with Yp and Yw simulated with CWD (i.e. little bias and an RMSE of 12-19% of the absolute mean). We conclude that results from studies that rely on GWD to simulate agricultural productivity in current and future climates are highly uncertain. An alternative approach would impose a climate scenario on location-specific observed daily weather databases combined with an appropriate upscaling method. PMID:23801639

  7. Impact of derived global weather data on simulated crop yields

    PubMed Central

    van Wart, Justin; Grassini, Patricio; Cassman, Kenneth G

    2013-01-01

    Crop simulation models can be used to estimate impact of current and future climates on crop yields and food security, but require long-term historical daily weather data to obtain robust simulations. In many regions where crops are grown, daily weather data are not available. Alternatively, gridded weather databases (GWD) with complete terrestrial coverage are available, typically derived from: (i) global circulation computer models; (ii) interpolated weather station data; or (iii) remotely sensed surface data from satellites. The present study's objective is to evaluate capacity of GWDs to simulate crop yield potential (Yp) or water-limited yield potential (Yw), which can serve as benchmarks to assess impact of climate change scenarios on crop productivity and land use change. Three GWDs (CRU, NCEP/DOE, and NASA POWER data) were evaluated for their ability to simulate Yp and Yw of rice in China, USA maize, and wheat in Germany. Simulations of Yp and Yw based on recorded daily data from well-maintained weather stations were taken as the control weather data (CWD). Agreement between simulations of Yp or Yw based on CWD and those based on GWD was poor with the latter having strong bias and large root mean square errors (RMSEs) that were 26–72% of absolute mean yield across locations and years. In contrast, simulated Yp or Yw using observed daily weather data from stations in the NOAA database combined with solar radiation from the NASA-POWER database were in much better agreement with Yp and Yw simulated with CWD (i.e. little bias and an RMSE of 12–19% of the absolute mean). We conclude that results from studies that rely on GWD to simulate agricultural productivity in current and future climates are highly uncertain. An alternative approach would impose a climate scenario on location-specific observed daily weather databases combined with an appropriate upscaling method. PMID:23801639

  8. Optical Remote Sensing For Prediction Of Crop Yields

    NASA Astrophysics Data System (ADS)

    Steven, M. D.

    1982-02-01

    Recent studies have determined the efficiency of crop production by relating the rate of increase of dry matter in healthy growing crops to the interception of sunlight. In addition to knowledge of the incident light, such studies require measurement of light transmission in the crop, or timely information about leaf area for light interception to be estimated. Transmission measurements are necessarily confined to small areas while traditional methods of determining leaf area are laborious and often require destructive sampling of part of the crop. Remote sensing techniques offer a cheap, non-destructive system for sampling large areas. An airborne sensor is used to detect solar radiation reflected from crops in two spectral bands: the near infra-red band (780 - 940 nm) is strongly reflected by leaves due to the porous structure of the mesophyll; the red band (600 - 660 nm) is strongly absorbed by chlorophyll in the leaves. The ratio of red/infra-red reflected fluxes decreases with the percentage cover of healthy green leaf and is largely independent of the effects of varying solar irradiance. Measurements made over sugar beet showed that during the main period of growth, spectral ratios were linearly related to leaf cover and light interception. There was some evidence of hysteresis later in the season when the spectral ratios tended to increase in spite of constant leaf cover, and this may indicate senescence of the leaves and loss of chlorophyll. These relationships are consistent for a wide variety of crops and allow the light interception by the crop to be estimated by a single spectral measurement from above. This information may be used to predict future rates of growth and ultimately, crop yields.

  9. Soil properties affecting wheat yields following drilling-fluid application.

    PubMed

    Bauder, T A; Barbarick, K A; Ippolito, J A; Shanahan, J F; Ayers, P D

    2005-01-01

    Oil and gas drilling operations use drilling fluids (mud) to lubricate the drill bit and stem, transport formation cuttings to the surface, and seal off porous geologic formations. Following completion of the well, waste drilling fluid is often applied to cropland. We studied potential changes in soil compaction as indicated by cone penetration resistance, pH, electrical conductivity (EC(e)), sodium adsorption ratio (SAR), extractable soil and total straw and grain trace metal and nutrient concentrations, and winter wheat (Triticum aestivum L. 'TAM 107') grain yield following water-based, bentonitic drilling-fluid application (0-94 Mg ha(-1)) to field test plots. Three methods of application (normal, splash-plate, and spreader-bar) were used to study compaction effects. We measured increasing SAR, EC(e), and pH with drilling-fluid rates, but not to levels detrimental to crop production. Field measurements revealed significantly higher compaction within areas affected by truck travel, but also not enough to affect crop yield. In three of four site years, neither drilling-fluid rate nor application method affected grain yield. Extractions representing plant availability and plant analyses results indicated that drilling fluid did not significantly increase most trace elements or nutrient concentrations. These results support land application of water-based bentonitic drilling fluids as an acceptable practice on well-drained soils using controlled rates. PMID:16091622

  10. Seeing is believing I: The use of thermal sensing from satellite imagery to predict crop yield

    NASA Astrophysics Data System (ADS)

    B, Potgieter A.; D, Rodriguez; B, Power; J, Mclean; P, Davis

    2014-02-01

    Volatility in crop production has been part of the Australian environment since cropping began with the arrival of the first European settlers. Climate variability is the main factor affecting crop production at national, state and local scales. At field level spatial patterns on yield production are also determined by spatially changing soil properties in interaction with seasonal climate conditions and weather patterns at critical stages in the crop development. Here we used a combination of field level weather records, canopy characteristics, and satellite information to determine the spatial performance of a large field of wheat. The main objective of this research is to determine the ability of remote sensing technologies to capture yield losses due to water stress at the canopy level. The yield, canopy characteristics (i.e. canopy temperature and ground cover) and seasonal conditions of a field of wheat (~1400ha) (-29.402° South and 149.508°, New South Wales, Australia) were continuously monitored during the winter of 2011. Weather and crop variables were continuously monitored by installing three automatic weather stations in a transect covering different positions and soils in the landscape. Weather variables included rainfall, minimum and maximum temperatures and relative humidity, and crop characteristics included ground cover and canopy temperature. Satellite imagery Landsat TM 5 and 7 was collected at five different stages in the crop cycle. Weather variables and crop characteristics were used to calculate a crop stress index (CSI) at point and field scale (39 fields). Field data was used to validate a spatial satellite image derived index. Spatial yield data was downloaded from the harvester at the different locations in the field. We used the thermal band (land surface temperature, LST) and enhanced vegetation index (EVI) bands from the MODIS (250 m for visible bands and 1km for thermal band) and a derived EVI from Landsat TM 7 (25 m for visible and

  11. Reductions in India's crop yield due to ozone

    NASA Astrophysics Data System (ADS)

    Ghude, Sachin D.; Jena, Chinmay; Chate, D. M.; Beig, G.; Pfister, G. G.; Kumar, Rajesh; Ramanathan, V.

    2014-08-01

    This bottom-up modeling study, supported by emission inventories and crop production, simulates ozone on local to regional scales. It quantifies, for the first time, potential impact of ozone on district-wise cotton, soybeans, rice, and wheat crops in India for the first decade of the 21st century. Wheat is the most impacted crop with losses of 3.5 ± 0.8 million tons (Mt), followed by rice at 2.1 ± 0.8 Mt, with the losses concentrated in central and north India. On the national scale, this loss is about 9.2% of the cereals required every year (61.2 Mt) under the provision of the recently implemented National Food Security Bill (in 2013) by the Government of India. The nationally aggregated yield loss is sufficient to feed about 94 million people living below poverty line in India.

  12. Nematode Numbers and Crop Yield in a Fenamiphos-Treated Sweet Corn-Sweet Potato-Vetch Cropping System

    PubMed Central

    Johnson, A. W.; Dowler, C. C.; Glaze, N. C.; Chalfant, R. B.; Golden, A. M.

    1992-01-01

    Nematode population densities and yield of sweet corn and sweet potato as affected by the nematicide fenamiphos, in a sweet corn-sweet potato-vetch cropping system, were determined in a 5-year test (1981-85). Sweet potato was the best host of Meloidogyne incognita of these three crops. Fenamiphos 15G (6.7 kg a.i./ha) incorporated broadcast in the top 15 cm of the soil layer before planting of each crop increased (P ≤ 0.05) yields of sweet corn in 1981 and 1982 and sweet potato number 1 grade in 1982 and 1983. Yield of sweet corn and numbers of M. incognita second-stage juveniles (J2) in the soil each month were negatively correlated from planting (r = - 0.47) to harvest (r = -0.61) in 1982. Yield of number 1 sweet potato was inversely related to numbers of J2 in the soil in July-October 1982 and July-September 1983. Yield of cracked storage roots was positively related to the numbers of J2 in the soil on one or more sampling dates in all years except 1985. Some factor(s), such as microbial degradation, resistant M. incognita development, or environment, reduced the effect of fenamiphos. PMID:19283032

  13. Nematode numbers and crop yield in a fenamiphos-treated sweet corn-sweet potato-vetch cropping system.

    PubMed

    Johnson, A W; Dowler, C C; Glaze, N C; Chalfant, R B; Golden, A M

    1992-12-01

    Nematode population densities and yield of sweet corn and sweet potato as affected by the nematicide fenamiphos, in a sweet corn-sweet potato-vetch cropping system, were determined in a 5-year test (1981-85). Sweet potato was the best host of Meloidogyne incognita of these three crops. Fenamiphos 15G (6.7 kg a.i./ha) incorporated broadcast in the top 15 cm of the soil layer before planting of each crop increased (P yields of sweet corn in 1981 and 1982 and sweet potato number 1 grade in 1982 and 1983. Yield of sweet corn and numbers of M. incognita second-stage juveniles (J2) in the soil each month were negatively correlated from planting (r = - 0.47) to harvest (r = -0.61) in 1982. Yield of number 1 sweet potato was inversely related to numbers of J2 in the soil in July-October 1982 and July-September 1983. Yield of cracked storage roots was positively related to the numbers of J2 in the soil on one or more sampling dates in all years except 1985. Some factor(s), such as microbial degradation, resistant M. incognita development, or environment, reduced the effect of fenamiphos. PMID:19283032

  14. The fingerprint of climate trends on European crop yields

    PubMed Central

    Moore, Frances C.; Lobell, David B.

    2015-01-01

    Europe has experienced a stagnation of some crop yields since the early 1990s as well as statistically significant warming during the growing season. Although it has been argued that these two are causally connected, no previous studies have formally attributed long-term yield trends to a changing climate. Here, we present two statistical tests based on the distinctive spatial pattern of climate change impacts and adaptation, and explore their power under a range of parameter values. We show that statistical power for the identification of climate change impacts is high in many settings, but that power for identifying adaptation is almost always low. Applying these tests to European agriculture, we find evidence that long-term temperature and precipitation trends since 1989 have reduced continent-wide wheat and barley yields by 2.5% and 3.8%, respectively, and have slightly increased maize and sugar beet yields. These averages disguise large heterogeneity across the continent, with regions around the Mediterranean experiencing significant adverse impacts on most crops. This result means that climate trends can account for ∼10% of the stagnation in European wheat and barley yields, with likely explanations for the remainder including changes in agriculture and environmental policies. PMID:25691735

  15. Perun: The System For Seasonal Crop Yield Forecasting Based On The Crop Model and Weather Generator

    NASA Astrophysics Data System (ADS)

    Dubrovsky, M.; Zalud, Z.; Trnka, M.; Haberle, J.; Pesice, P.

    The main purpose of the computer system PERUN, which is now being developed, is the probabilistic seasonal crop yield forecasting. The crop yields (winter wheat and spring barley in the first step) are simulated by crop model WOFOST. The input daily weather series consist of observed data, which are available in the date of forecast issuance, and synthetic data, which follow up with the observed data till the end of the crop model simulation. The synthetic weather series are generated by stochastic generator Met&Roll conditionally on the seasonal weather forecast. The probabilis- tic forecast is based on multiple crop model runs. To provide the six daily weather characteristics required for crop model simulation (precipitation, solar radiation, max- imum and minimum temperatures, air humidity, wind speed), the previous WGEN- like four-variate version of Met&Roll generator was supplemented by a new module. This module adds wind speed and air humidity (necessary to calculate evapotranspi- ration) using the nearest neighbours resampling from the observed data. Because of the problems with availability and/or accuracy of wind and humidity data, the source code of the WOFOST model was modified and allows now to switch between Penman and Makkink methods of calculating the evapotranspiration (the daily values of wind speed and humidity are not required in the Makkink method). The contribution will address following items: 1) Structure of the PERUN system: components and their inputs and outputs. Modifications to WOFOST crop model and Met&Roll generator will be discussed. 2) Validation of the WOFOST crop model. The accuracy obtained using the Penman and Makkink methods will be compared. 3) Demonstration of the forecast accuracy in dependence on the date of issuance. Acknowledgement: The system PERUN is being developed within the frame of project QC1316 sponsored by the Czech National Agency for Agricultural Research (NAZV).

  16. Application of a CROPWAT Model to Analyze Crop Yields in Nicaragua

    NASA Astrophysics Data System (ADS)

    Doria, R.; Byrne, J. M.

    2013-12-01

    ABSTRACT Changes in climate are likely to influence crop yields due to varying evapotranspiration and precipitation over agricultural regions. In Nicaragua, agriculture is extensive, with new areas of land brought into production as the population increases. Nicaraguan staple food items (maize and beans) are produced mostly by small scale farmers with less than 10 hectares, but they are critical for income generation and food security for rural communities. Given that the majority of these farmers are dependent on rain for crop irrigation, and that maize and beans are sensitive to variations in temperature and rainfall patterns, the present study was undertaken to assess the impact of climate change on these crop yields. Climate data were generated per municipio representing the three major climatic zones of the country: the wet Pacific lowland, the cooler Central highland, and the Caribbean lowland. Historical normal climate data from 1970-2000 (baseline period) were used as input to CROPWAT model to analyze the potential and actual evapotranspiration (ETo and ETa, respectively) that affects crop yields. Further, generated local climatic data of future years (2030-2099) under various scenarios were inputted to the CROPWAT to determine changes in ETo and ETa from the baseline period. Spatial variability maps of both ETo and ETa as well as crop yields were created. Results indicated significant variation in seasonal rainfall depth during the baseline period and predicted decreasing trend in the future years that eventually affects yields. These maps enable us to generate appropriate adaptation measures and best management practices for small scale farmers under future climate change scenarios. KEY WORDS: Climate change, evapotranspiration, CROPWAT, yield, Nicaragua

  17. Impacts of future climate change on potential yields of major crops in China

    NASA Astrophysics Data System (ADS)

    Yin, Y.; Tang, Q.; Liu, X.

    2014-05-01

    Climate change may affect crop development and yield, and consequently cast a shadow of doubt over China's food self-sufficiency efforts. In this study we used the model projections of a couple of global gridded crop models (GGCMs) to assess the effects of future climate change on the potential yields of the major crops (i.e. wheat, rice, maize and soybean) over China. The GGCMs were forced with the bias-corrected climate data from 5 global climate models (GCMs) under the Representative Concentration Pathways (RCP) 8.5 which were made available by the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP). The results show that the potential yields of rice may increase over a large portion of China. Climate change may benefit food productions over the high-altitude and cold regions where are outside current main agricultural area. However, the potential yield of maize, soybean and wheat may decrease in a large portion of the current main crop planting areas such as North China Plain. Development of new agronomic management strategy may be useful for coping with climate change in the areas with high risk of yield reduction.

  18. Coupling crop growth and hydrologic models to predict crop yield with spatial analysis technologies

    NASA Astrophysics Data System (ADS)

    Jia, Yangwen; Shen, Suhui; Niu, Cunwen; Qiu, Yaqin; Wang, Hao; Liu, Yu

    2011-01-01

    This paper analyzes climate change impact on crop yield of winter wheat, a main crop in the water-stressed Haihe River Basin in North China. An integrated analysis was carried out by coupling the World Food Studies (WOFOST) crop growth model and the distributed hydrological model describing the water and energy transfer processes in large river basins (WEP-L). Various spatial analysis technologies, including remote sensing and geographical information system, were woven together to support model calibration and validation. The WOFOST model was calibrated and validated using the winter wheat data collected in two successive years. Effort was then extended to calibrate and validate the WEP-L distributed hydrologic model for the whole basin. Such an effort was collectively supported by using the remote sensing evapotranspiration and biomass data, the in situ river flow data, and the wheat yield statistical data. With this integration, the wheat yield from 2010 to 2030 can be predicted under the given climate change impact corresponding to Intergovernmental Panel on Climate Change A1B, A2, and B1 scenarios. Given the prescribed climate change scenarios, at the basin-scale, the winter wheat yield may increase in terms of the annual average; however, the long-term trend is geared toward a decreasing yield with significant fluctuations. The colder hilly areas with current lower yield may significantly increase due to possible future temperature rise while the warmer plain areas with current higher yield may slightly increase or decrease. Despite the data collected thus far, it is evident that further studies are needed to reduce the uncertainties of these predictions of climate change effect on winter wheat grain yield.

  19. The Fingerprint of Climate Trends on European Crop Yields

    NASA Astrophysics Data System (ADS)

    Moore, F.; Lobell, D. B.

    2014-12-01

    Europe has experienced a stagnation of some crop yields since the early-1990s as well as statistically-significant warming during the growing-season. While it has been argued that these two are causally connected, no previous studies have formally attributed long-term European yield trends to a changing climate. Here we present two statistical tests based on the distinctive spatial pattern of climate change impacts and adaptation, and explore their power under a range of parameter values. We show that statistical power for the identification of climate change impacts is high in many settings, but that power for identifying adaptation is almost always low. Applying these test to European agriculture, we find evidence that long-term temperature and precipitation trends have reduced continent-wide wheat, maize, and barley yields by 2.7%, 1.1%, and 3.9% respectively, and have increased sugarbeet yields by 1.0%. This can account for approximately 10% of the yield stagnation in Europe, with changes in agricultural and environmental policies likely explaining the remainder.

  20. Combining explanatory crop models with geospatial data for regional analyses of crop yield using field-scale modeling units

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop models are computational tools used for predicting crop yield and natural resource requirements and are frequently used to evaluate different climate or management scenarios at a specific site. However, problems involving land use or climate change would benefit from conducting crop simulation...

  1. Modeling with Limited Data: The Influence of Crop Rotation and Management on Weed Communities and Crop Yield Loss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Theory and models of crop yield loss from weed competition have lead to decision models to help growers with cost-effective tactical weed management. Weed management decision models are available for multiple-species populations in a single season of several crops. Growers also rely on crop rotation...

  2. Global crop yield response to extreme heat stress under multiple climate change futures

    NASA Astrophysics Data System (ADS)

    Deryng, D.; Conway, D.; Ramankutty, N.; Price, J.; Warren, R.

    2014-12-01

    Extreme heat stress during the crop reproductive period can be critical for crop productivity. Projected changes in the frequency and severity of extreme climatic events are expected to negatively impact crop yields and global food production. This study applies the global crop model PEGASUS to quantify, for the first time at the global scale, impacts of extreme heat stress on maize, spring wheat and soybean yields resulting from 72 climate change scenarios for the 21st century. Our results project maize to face progressively worse impacts under a range of RCPs but spring wheat and soybean to improve globally through to the 2080s due to CO2 fertilization effects, even though parts of the tropic and sub-tropic regions could face substantial yield declines. We find extreme heat stress at anthesis (HSA) by the 2080s (relative to the 1980s) under RCP 8.5, taking into account CO2 fertilization effects, could double global losses of maize yield (dY = -12.8 ± 6.7% versus -7.0 ± 5.3% without HSA), reduce projected gains in spring wheat yield by half (dY = 34.3 ± 13.5% versus 72.0 ± 10.9% without HSA) and in soybean yield by a quarter (dY = 15.3 ± 26.5% versus 20.4 ± 22.1% without HSA). The range reflects uncertainty due to differences between climate model scenarios; soybean exhibits both positive and negative impacts, maize is generally negative and spring wheat generally positive. Furthermore, when assuming CO2 fertilization effects to be negligible, we observe drastic climate mitigation policy as in RCP 2.6 could avoid more than 80% of the global average yield losses otherwise expected by the 2080s under RCP 8.5. We show large disparities in climate impacts across regions and find extreme heat stress adversely affects major producing regions and lower income countries.

  3. Stagnating crop yields: An overlooked risk for the carbon balance of agricultural soils?

    PubMed

    Wiesmeier, Martin; Hübner, Rico; Kögel-Knabner, Ingrid

    2015-12-01

    The carbon (C) balance of agricultural soils may be largely affected by climate change. Increasing temperatures are discussed to cause a loss of soil organic carbon (SOC) due to enhanced decomposition of soil organic matter, which has a high intrinsic temperature sensitivity. On the other hand, several modeling studies assumed that potential SOC losses would be compensated or even outperformed by an increased C input by crop residues into agricultural soils. This assumption was based on a predicted general increase of net primary productivity (NPP) as a result of the CO2 fertilization effect and prolonged growing seasons. However, it is questionable if the crop C input into agricultural soils can be derived from NPP predictions of vegetation models. The C input in European croplands is largely controlled by the agricultural management and was strongly related to the development of crop yields in the last decades. Thus, a glance at past yield development will probably be more instructive for future estimations of the C input than previous modeling approaches based on NPP predictions. An analysis of European yield statistics indicated that yields of wheat, barley and maize are stagnating in Central and Northern Europe since the 1990s. The stagnation of crop yields can probably be related to a fundamental change of the agricultural management and to climate change effects. It is assumed that the soil C input is concurrently stagnating which would necessarily lead to a decrease of agricultural SOC stocks in the long-term given a constant temperature increase. Remarkably, for almost all European countries that are faced with yield stagnation indications for agricultural SOC decreases were already found. Potentially adverse effects of yield stagnation on the C balance of croplands call for an interdisciplinary investigation of its causes and a comprehensive monitoring of SOC stocks in agricultural soils of Europe. PMID:26235605

  4. Global crop yield response to extreme heat stress under multiple climate change futures

    NASA Astrophysics Data System (ADS)

    Deryng, Delphine; Conway, Declan; Ramankutty, Navin; Price, Jeff; Warren, Rachel

    2014-03-01

    Extreme heat stress during the crop reproductive period can be critical for crop productivity. Projected changes in the frequency and severity of extreme climatic events are expected to negatively impact crop yields and global food production. This study applies the global crop model PEGASUS to quantify, for the first time at the global scale, impacts of extreme heat stress on maize, spring wheat and soybean yields resulting from 72 climate change scenarios for the 21st century. Our results project maize to face progressively worse impacts under a range of RCPs but spring wheat and soybean to improve globally through to the 2080s due to CO2 fertilization effects, even though parts of the tropic and sub-tropic regions could face substantial yield declines. We find extreme heat stress at anthesis (HSA) by the 2080s (relative to the 1980s) under RCP 8.5, taking into account CO2 fertilization effects, could double global losses of maize yield (ΔY = -12.8 ± 6.7% versus - 7.0 ± 5.3% without HSA), reduce projected gains in spring wheat yield by half (ΔY = 34.3 ± 13.5% versus 72.0 ± 10.9% without HSA) and in soybean yield by a quarter (ΔY = 15.3 ± 26.5% versus 20.4 ± 22.1% without HSA). The range reflects uncertainty due to differences between climate model scenarios; soybean exhibits both positive and negative impacts, maize is generally negative and spring wheat generally positive. Furthermore, when assuming CO2 fertilization effects to be negligible, we observe drastic climate mitigation policy as in RCP 2.6 could avoid more than 80% of the global average yield losses otherwise expected by the 2080s under RCP 8.5. We show large disparities in climate impacts across regions and find extreme heat stress adversely affects major producing regions and lower income countries.

  5. Dryland Crop Yields and Soil Organic Matter as Influenced by Long-Term Tillage and Cropping Sequence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel management practices are needed to improve the declining dryland crop yields and soil organic matter using conventional farming practices in the northern Great Plains. We evaluated the 21-yr effect of tillage and cropping sequence on dryland grain and biomass (stems + leaves) yields of spring ...

  6. Long-term Tillage and Cropping Sequence Effect on Dryland Crop Yields and Carbon and Nitrogen Cycling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improved management practices are needed to increase dryland crop yields and soil organic matter compared with conventional farming practices in the northern Great Plains. We evaluated the 21-yr effect of tillage and cropping sequence on dryland grain and biomass (stems + leaves) yields and N uptake...

  7. Food for Thought: Crop Yields in the Columbia River Basin in an Altered Future

    NASA Astrophysics Data System (ADS)

    Rajagopalan, K.; Chinnayakanahalli, K.; Nelson, R.; Stockle, C.; Kruger, C.; Brady, M.; Adam, J. C.

    2013-12-01

    Growth of global population and food consumption in the next several decades is expected to result in a food security challenge. Strategies to address this challenge, such as enhancing agricultural productivity and resiliency, need to be considered within the context of a full range of plausible consequences so as to identify investments that create win-win-win scenarios for the environment, economy, and society. Regional earth systems models can provide the necessary scale-appropriate framework to inform the decision making context for adaptation strategies, especially in the context of global change. In an altered future, changes to climate, technology and socioeconomics affect regional agriculture both directly and indirectly. These effects are not independent and an integrated process-based model may better capture unanticipated non-linear and non-monotonic responses and feedbacks over time . BioEarth is a research initiative designed to explore the coupling of multiple stand-alone earth systems models to generate usable information for agricultural and natural resource decision making at the regional scale at decadal time-steps. This project focuses on the U.S. Pacific Northwest (PNW) region and is a framework that integrates atmospheric, terrestrial, aquatic, and economic models. We apply component models of BioEarth to the Columbia River basin in the PNW to study the direct and indirect impacts of climate change on regional irrigated and dryland crop yields for a variety of annual and perennial crops. Results indicate that the net effect of climate change on crop yields is dependent on the crop type. There is a negative effect of temperature on yields for most crops. Dryland winter wheat is a notable exception. With warming, although the available growing season increases, faster thermal accumulation results in a shorter time to maturity. Precipitation changes in the region have a positive impact on dryland agriculture. Carbon dioxide (CO2) fertilization has

  8. 7 CFR 1412.32 - Direct payment yield for designated oilseed and pulse crops.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... oilseed and pulse crops. (a) The direct payment yield for designated oilseeds for which a yield was not... designated oilseed for which a yield was not established by September 30, 2007, and for pulse crops on the... 7 Agriculture 10 2013-01-01 2013-01-01 false Direct payment yield for designated oilseed and...

  9. 7 CFR 1412.32 - Direct payment yield for designated oilseed and pulse crops.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... oilseed and pulse crops. (a) The direct payment yield for designated oilseeds for which a yield was not... designated oilseed for which a yield was not established by September 30, 2007, and for pulse crops on the... 7 Agriculture 10 2012-01-01 2012-01-01 false Direct payment yield for designated oilseed and...

  10. 7 CFR 1412.32 - Direct payment yield for designated oilseed and pulse crops.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... oilseed and pulse crops. (a) The direct payment yield for designated oilseeds for which a yield was not... designated oilseed for which a yield was not established by September 30, 2007, and for pulse crops on the... 7 Agriculture 10 2014-01-01 2014-01-01 false Direct payment yield for designated oilseed and...

  11. Detecting crop yield reduction due to irrigation-induced soil salinization in South-West Russia

    NASA Astrophysics Data System (ADS)

    Argaman, E.; Beets, W.; Croes, J.; Keesstra, S.; Verzandvoort, S.; Zeiliguer, A.

    2012-04-01

    The South-European part of the Russian Federation has experienced serious land degradation in the form of soil salinization since the 1960s. This land degradation was caused by intensive, large-scale irrigation on reclaimed land in combination with the salt-rich nature of the substrate. Alkaline soil salinity is believed to be an important factor decreasing crop yield in this area. A large research effort has been directed to the effects of soil salinity on crops, there is a need for simple, easily determinable indicators of crop health and soil salinity in irrigated systems, that can help to detect crop water stress in an early stage. The objectives of this research were to study the effects of soil salinity and vegetation water stress on the performance of alfalfa crop yield and physiological crop properties, and to study the possibility to measure soil salinity and alkalinity and the crop water stress index at plot level using a thermal gun and a regular digital camera. The study area was located in Saratov District, in the South-West part of Russia. Variables on the surface energy balance, crop properties, soil properties and visible reflectance were measured on plots with alfalfa cultures in two fields with and without signs of alkaline soil salinity, and with and without irrigation in July 2009. The research showed no clear adverse effects of soil salinity and soil alkalinity on crop yield and physiological crop properties. Soil salinity, as reflected by the electric conductivity, positively affected the root biomass of alfalfa in the range of 0.15 to 1.52 dS/m . This was a result of EC levels being below the documented threshold to negatively affect Alfalfa, as would be the case in truly saline soils. The soil pH also showed a positive correlation with root biomass within the range of pH 6.2 and 8.5 . From the literature these pH values are generally believed to be too high to exhibit a positive relationship with root biomass. No relationship was found

  12. USING MULTISPECTRAL IMAGERY AND LINEAR SPECTRAL UNMIXING TECHNIQUES FOR ESTIMATING CROP YIELD VARIABILITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetation indices derived from multispectral imagery are commonly used to extract crop growth and yield information. Spectral unmixing techniques provide an alternative approach to quantifying crop canopy abundance within each image pixel and have the potential for mapping crop yield variability. T...

  13. Airborne hyperspectral imagery and linear spectral unmixing for mapping variation in crop yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetation indices derived from remotely sensed imagery are commonly used to estimate crop yields. Spectral unmixing techniques provide an alternative approach to quantifying crop canopy abundance within each pixel of an image and have the potential for mapping crop yield variability. The objective ...

  14. The Role of Nutrient Efficient Plants in Improving Crop Yields in the Twenty First Century

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the 21st century, nutrient efficient plants will play a major role in increasing crop yields compared to the 20th century, mainly due to limited land and water resources available for crop production, higher cost of inorganic fertilizer inputs, and declining trends in crop yields globally. Furthe...

  15. Global patterns of the trends in satellite-derived crop yield proxy, temperature and soil moisture

    NASA Astrophysics Data System (ADS)

    Sakai, T.; Iizumi, T.; Sakurai, G.; Okada, M.; Nishimori, M.

    2014-12-01

    Crop productivity (yield) is sensitive to climate variability and change. To inform stakeholders, including food agencies in food-importing countries, about future variations in food supply associated with climate variability and change, understanding major climatic drivers of the spatiotemporal variations in crop yield over global cropland during the last few decades is crucial. Although remote sensing has difficulty distinguishing individual crops and misses entire cropping cycles in areas where extensive cloud cover during the monsoon limits satellite observations, it is still useful in deriving a proxy of crop yield over large spatial domain and estimating the impacts on crop yield proxy due to climate, including land-surface temperature and surface-layer soil moisture. This study presents an attempt to globally depict the impact of climate change on crop yield proxy by applying a time series analysis to MODIS and AMSR-E satellite images. The crop yield proxy used was the annual maximum or integrated MODIS-derived NDVI during the growing period predefined on the basis of the global crop calendar. The trends in the crop yield proxy in the interval 2001-2013 appeared positive in higher latitudes and negative in lower latitudes. In higher latitudes (and thus colder regions), the increased land-surface temperature led to an increase in crop yield in part due to the enhanced photosynthesis rate. In contrast, the crop yield proxy showed negative correlation with land-surface temperature in lower latitudes. The increased temperature might decrease crop yield by increasing evapotranspiration rate, plant respiration and/or heat stress. The crop yield proxy was also correlated with the AMSR-E-derived soil moisture, although the geographical distribution of soil moisture was highly heterogeneous.

  16. Irrigation with desalinated water: A step toward increasing water saving and crop yields

    NASA Astrophysics Data System (ADS)

    Silber, Avner; Israeli, Yair; Elingold, Idan; Levi, Menashe; Levkovitch, Irit; Russo, David; Assouline, Shmuel

    2015-01-01

    We examined the impact of two different approaches to managing irrigation water salinity: salt leaching from the field ("conventional" management) and water desalination before field application ("alternative" management). Freshwater commonly used for irrigation (FW) and desalinated water (DS) were applied to the high-water-demanding crop banana at four different rates. Both irrigation rate and water salinity significantly affected yield. DS application consistently produced higher yields than FW, independently of irrigation rate. The highest yield for FW-irrigation was achieved with the highest irrigation rate, whereas the same yield was obtained in the case of DS-irrigation with practically half the amount of water. Yield decreased with FW-irrigation, even when the water salinity, ECi, was lower than the limit considered safe for soil and crops. Irrigating with FW provided a massive amount of salt which accumulated in the rhizosphere, inducing increased osmotic potential of the soil solution and impairing plant water uptake. Furthermore, applying the "conventional" management, a significant amount of salt is leached from the rhizosphere, accumulating in deeper soil layers, and eventually reaching groundwater reservoirs, thus contributing to the deterioration of both soil and water quality. Removal of salt excess from the water before it reaches the field by means of DS-irrigation may save significant amounts of irrigation water by reducing the salt leaching requirements while increasing yield and improving fruit quality, and decreasing salt load in the groundwater.

  17. Nitrogen fertilization affects corn cellulosic biomass and ethanol yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research results on the effects of N management on corn (Zea mays L.) grain production in high-yielding cropping systems are widely available, but information on its effects on cellulosic ethanol potential from corn stover and cobs is limited. Stover and cob biomass and respective ethanol yields all...

  18. ORECCL - Summary of a national database on energy crop landbase, yields, and costs

    SciTech Connect

    Graham, R.L.; Allison, L.J.; Becker, D.A.

    1997-07-01

    The Biofuels Feedstock Development Program at Oak Ridge National Laboratory has developed a county-level database on energy crops-the Oak Ridge Energy Crop County-Level database (RECCL). This database encompasses all U.S. counties and provides easy access to energy crop information specific to a state or county. The database contains predictions of energy crop yields and farmgate prices along with county-level data on the acreage of land suitable for energy crop production. This paper describes the database and presents state-level summary statistics on land suitable for energy crop production and average predicted yields and farmgate prices.

  19. 7 CFR 1412.32 - Direct payment yield for designated oilseed and pulse crops.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Direct payment yield for designated oilseed and pulse... oilseed and pulse crops. (a) The direct payment yield for designated oilseeds for which a yield was not established by September 30, 2007, and pulse crops for the farm will be determined by multiplying the...

  20. Projecting crop yield in northern high latitude area.

    PubMed

    Matsumura, Kanichiro

    2014-01-01

    validation periods is used. To show the reproducing projection between observed and calculated values, the root mean squared error for skill score (RMSE SS) with the persistence model serving as the reference model is used. The persistence model is used as a benchmark. The results show that SADs near USA border show better RMSE SS values and mode 3's time coefficients can be a useful predictor especially for inland province such as Manitoba. Among 27 Canadian Prairie's SADs with perfect yield data, 67% of Alberta's SADs, 86% of Manitoba's SADs, and 77% of Saskatchewan's SADs can get positive skill scores. In each SAD, future yield projection is calculated applying predictors in 2013 for the obtained eight sets of models and eight sets of forecasted values in 2013 are averaged and a near future projection result is obtained. Series of outputs including calculated forecasted yield value in each SAD is provided by smart phone application. A system for providing climatic condition for a point with a permission of Climatic Research Unit - University of East Anglia and for obtaining patent is proposed. There are several patented systems similar to the system proposed in this paper. However, these patents are different in essence. The system proposed in this paper consists of two parts. First part is to estimate equations using time series data. The second part is to acquire and apply latest climatic conditions for obtained equations and calculate future projection. If the procedure is refined and devices are originally developed, series of idea can be patented. For future work, crop index, Hokkaido is also introduced. PMID:25733071

  1. Evaluation of preservation methods for improving biogas production and enzymatic conversion yields of annual crops

    PubMed Central

    2011-01-01

    Background The use of energy crops and agricultural residues is expected to increase to fulfil the legislative demands of bio-based components in transport fuels. Ensiling methods, adapted from the feed sector, are suitable storage methods to preserve fresh crops throughout the year for, for example, biogas production. Various preservation methods, namely ensiling with and without acid addition for whole crop maize, fibre hemp and faba bean were investigated. For the drier fibre hemp, alkaline urea treatment was studied as well. These treatments were also explored as mild pretreatment methods to improve the disassembly and hydrolysis of these lignocellulosic substrates. Results The investigated storage treatments increased the availability of the substrates for biogas production from hemp and in most cases from whole maize but not from faba bean. Ensiling of hemp, without or with addition of formic acid, increased methane production by more than 50% compared to fresh hemp. Ensiling resulted in substantially increased methane yields also from maize, and the use of formic acid in ensiling of maize further enhanced methane yields by 16%, as compared with fresh maize. Ensiled faba bean, in contrast, yielded somewhat less methane than the fresh material. Acidic additives preserved and even increased the amount of the valuable water-soluble carbohydrates during storage, which affected most significantly the enzymatic hydrolysis yield of maize. However, preservation without additives decreased the enzymatic hydrolysis yield especially in maize, due to its high content of soluble sugars that were already converted to acids during storage. Urea-based preservation significantly increased the enzymatic hydrolysability of hemp. Hemp, preserved with urea, produced the highest carbohydrate increase of 46% in enzymatic hydrolysis as compared to the fresh material. Alkaline pretreatment conditions of hemp improved also the methane yields. Conclusions The results of the present

  2. A Crop Simulation System for Integrating Remote Sensing and Climate Information to Reduce Model Uncertainty in Crop Yield Assessments

    NASA Astrophysics Data System (ADS)

    Ines, A. M.; Honda, K.; Yui, A.

    2012-12-01

    Uncertainties in crop yield assessments are caused by many factors, including an imperfect model, model parameters and modeling assumptions, as well as errors in data inputs, e.g. climate. Here, we present a crop simulation system that aims to reduce uncertainty in crop yield assessment due to model and data uncertainties. The system uses DSSAT-CSM as the core crop simulation model. The simulation strategy is two-folds: i) crop model parameter estimation and ii) simulation and prediction mode. In i) a noisy Monte Carlo genetic algorithm (NMCGA) is used to estimate crop, soil and management parameters and their uncertainties, where field and remote sensing data can be used in the process. In ii) simulations can be done in an incremental way, where climate data until the current day is used as inputs to the crop model while the climate inputs for rest of the simulation period are generated by a stochastic weather generator based on climatological or climate forecasts information. Also, in the prediction mode, an ensemble Kalman filter (EnKF) can be used to update crop model state variables, e.g., leaf area index (LAI) and soil moisture from remote sensing and field sensors, this can be used in tandem with the climate merging mechanism within the crop simulation system. A case study on wheat modeling in Hokkaido, Japan will be presented. Model uncertainty assessment and implications of the crop simulation system for crop assessment will be discussed.

  3. The limits of crop productivity: validating theoretical estimates and determining the factors that limit crop yields in optimal environments

    NASA Technical Reports Server (NTRS)

    Bugbee, B.; Monje, O.

    1992-01-01

    Plant scientists have sought to maximize the yield of food crops since the beginning of agriculture. There are numerous reports of record food and biomass yields (per unit area) in all major crop plants, but many of the record yield reports are in error because they exceed the maximal theoretical rates of the component processes. In this article, we review the component processes that govern yield limits and describe how each process can be individually measured. This procedure has helped us validate theoretical estimates and determine what factors limit yields in optimal environments.

  4. Commercial Crop Yields Reveal Strengths and Weaknesses for Organic Agriculture in the United States

    PubMed Central

    Savage, Steven D.; Jabbour, Randa

    2016-01-01

    Land area devoted to organic agriculture has increased steadily over the last 20 years in the United States, and elsewhere around the world. A primary criticism of organic agriculture is lower yield compared to non-organic systems. Previous analyses documenting the yield deficiency in organic production have relied mostly on data generated under experimental conditions, but these studies do not necessarily reflect the full range of innovation or practical limitations that are part of commercial agriculture. The analysis we present here offers a new perspective, based on organic yield data collected from over 10,000 organic farmers representing nearly 800,000 hectares of organic farmland. We used publicly available data from the United States Department of Agriculture to estimate yield differences between organic and conventional production methods for the 2014 production year. Similar to previous work, organic crop yields in our analysis were lower than conventional crop yields for most crops. Averaged across all crops, organic yield averaged 80% of conventional yield. However, several crops had no significant difference in yields between organic and conventional production, and organic yields surpassed conventional yields for some hay crops. The organic to conventional yield ratio varied widely among crops, and in some cases, among locations within a crop. For soybean (Glycine max) and potato (Solanum tuberosum), organic yield was more similar to conventional yield in states where conventional yield was greatest. The opposite trend was observed for barley (Hordeum vulgare), wheat (Triticum aestevum), and hay crops, however, suggesting the geographical yield potential has an inconsistent effect on the organic yield gap. PMID:27552217

  5. Commercial Crop Yields Reveal Strengths and Weaknesses for Organic Agriculture in the United States.

    PubMed

    Kniss, Andrew R; Savage, Steven D; Jabbour, Randa

    2016-01-01

    Land area devoted to organic agriculture has increased steadily over the last 20 years in the United States, and elsewhere around the world. A primary criticism of organic agriculture is lower yield compared to non-organic systems. Previous analyses documenting the yield deficiency in organic production have relied mostly on data generated under experimental conditions, but these studies do not necessarily reflect the full range of innovation or practical limitations that are part of commercial agriculture. The analysis we present here offers a new perspective, based on organic yield data collected from over 10,000 organic farmers representing nearly 800,000 hectares of organic farmland. We used publicly available data from the United States Department of Agriculture to estimate yield differences between organic and conventional production methods for the 2014 production year. Similar to previous work, organic crop yields in our analysis were lower than conventional crop yields for most crops. Averaged across all crops, organic yield averaged 80% of conventional yield. However, several crops had no significant difference in yields between organic and conventional production, and organic yields surpassed conventional yields for some hay crops. The organic to conventional yield ratio varied widely among crops, and in some cases, among locations within a crop. For soybean (Glycine max) and potato (Solanum tuberosum), organic yield was more similar to conventional yield in states where conventional yield was greatest. The opposite trend was observed for barley (Hordeum vulgare), wheat (Triticum aestevum), and hay crops, however, suggesting the geographical yield potential has an inconsistent effect on the organic yield gap. PMID:27552217

  6. A multi-model analysis of change in potential yield of major crops in China under climate change

    NASA Astrophysics Data System (ADS)

    Yin, Y.; Tang, Q.; Liu, X.

    2015-02-01

    Climate change may affect crop growth and yield, which consequently casts a shadow of doubt over China's food self-sufficiency efforts. In this study, we used the projections derived from four global gridded crop models (GGCropMs) to assess the effects of future climate change on the yields of the major crops (i.e., maize, rice, soybean and wheat) in China. The GGCropMs were forced with the bias-corrected climate data from five global climate models (GCMs) under Representative Concentration Pathway (RCP) 8.5, which were made available through the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP). The results show that the potential yields of the crops would decrease in the 21st century without carbon dioxide (CO2) fertilization effect. With the CO2 effect, the potential yields of rice and soybean would increase, while the potential yields of maize and wheat would decrease. The uncertainty in yields resulting from the GGCropMs is larger than the uncertainty derived from GCMs in the greater part of China. Climate change may benefit rice and soybean yields in high-altitude and cold regions which are not in the current main agricultural area. However, the potential yields of maize, soybean and wheat may decrease in the major food production area. Development of new agronomic management strategies may be useful for coping with climate change in the areas with a high risk of yield reduction.

  7. Analysis of Climate Change Impact on U.S. Crop Yields with Reanalysis Data

    NASA Astrophysics Data System (ADS)

    Kuwata, K.

    2014-12-01

    Increasing the world population, food security in the sense of supplying enough food has become more important. Cereals are considerable matter in food security issues, and production of cereals are heavily threatened by climate change. In 2012, terrible drought which might happen once in a hundred years, caused massive damage to the soybean and corn harvest. This event had impact on the agriculture industry in U.S., and led drastic increase of commodity price. To ensuring food security, influence of climate risk to food production should be comprehended quantitatively. We used ERA-Interim which includes temperature, dew-point, pressure, precipitation, solar radiation and wind speed product, to analyze the world condition of climate changes, and calculated warmth index and dew-point depression. Kira (1977) developed warmth index which has close relationship between distribution of plants living. Dew-point depression represents the wetness of atmosphere. Also, we analyzed crop yields statistics from USDA to clarify what kind of climate condition affect crop yields. Figure 1 shows variance distribution of warmth index. It can be said that area where contains high value of variance, is subject to extreme climatic changes. Figure 2 is a distribution map indicating whether warmth index was higher or lower than average value. In 2012, it was very hot in the wide range of the Russia and North America. Figure 3 shows correlation between yield index and ERA-Interim climate data at each month. Crop yields have been in trend of increasing because technology enhancements such as improving of breeds and cultivation have been occurred. Therefore, we calculated simple moving average as normal value and calculated yield index by dividing the normal value and annual yields (left Figure 3). If yield index was under 100, it was harvest failure in that year. In contrast, if yield index was higher than 100, it was good harvest in that year. In this result, temperature, warmth index and

  8. Effect of soil acidity factors on yields and foliar composition of tropical root crops

    SciTech Connect

    Abruna-Rodriguez, F.; Vicente-Chandler, J.I. Rivera, E.; Rodriguez, J.

    1982-09-01

    Tropical root crops, a major source of food for subsistence farmers, varied in their sensitivity to soil acidity factors. Tolerance to soil acidity is an important characteristic of crops for the humid tropics where soils are often very acid and lime-scarce and expensive. Experiments on two Ultisols and an Oxisol showed that three tropical root crops differed markedly in sensitivity to soil acicity factors. Yams (Dioscorea alata L.) were very sensitive to soil acidity with yields on a Ultisol decreasing from 70% of maximum when Al saturation of the effective cation exchange capacity of the soil was 10 to 25% of maximum when Al saturation was 40%. On the other hand, cassava (Manihot esculenta Crantz) was very tolerant to high levels of soil acidity, yielding about 85% of maximum with 60% Al saturation. Taniers (Xanthosoma sp.) were intermediate between yams and cassava in their tolerance to soil acidity yielding about 60% of maximum with 50% Al saturation of the soil. Foliar composition of cassava was not affected by soil acidity levels and that of yams and taniers was also unaffected except for Ca content which decreased with decreasing soil pH and increasing Al saturation.Response of these tropical root crops to soil acidity components was far more striking on Ultisols than on the Oxisol. For yams, soils should be limed to about pH 5.5 with essentially no exhangeable Al/sup 3 +/ present whereas high yields of taniers can be obtained at about pH 4.8 with 20% exchangeable Al/sup 3 +/ and of cassava at pH as low as 4.5 with 60% exchangeable Al/sup 3 +/.

  9. The Potato Systems Planner: Integrating Cropping System Impacts on Crop Yield and Quality, Soil Biology, Nutrient Cycling, Diseases, and Economics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Finding and developing profitable cropping systems is a high priority for the potato industry. Consequently, an interdisciplinary team of ARS scientists from the New England Plant, Soil, & Water Laboratory evaluated 14 different rotations for their impacts on crop yield and quality, nutrient availa...

  10. Long-term tillage and cropping sequence influence on dryland soil carbon, nitrogen, physical properties, and crop yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel management practices are needed to improve dryland soil C and N sequestration, N mineralization, soil physical properties, and crop yields in the northern Great Plains. We evaluated the 21-yr effect of tillage and cropping sequence on dryland soil aggregation, C and N storage, N mineralization...

  11. Lime effects on soil acidity, crop yield and aluminum chemistry in inland Pacific Northwest direct-seed cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pH of agricultural soils in the Inland Pacific Northwest (IPNW) has declined below established critical levels for cereal and grain legume crops. Our objective was to assess the effects of broadcast or subsurface banded lime treatments on soil acidity, crop yield, and aluminum (Al) chemistry in ...

  12. Earth Observation Based Canadian Crop Yield Forecasting -- Impact of Spatial Modeling Scale

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Daneshfar, B.; Chipanshi, A.; Champagne, C.; Davidson, A. M.

    2015-12-01

    Earth Observation (EO) based yield modelling has long been in development as an alternative method to the traditional survey based methods in forecasting the regional and global crop yield. However, it is only in last decade or so, with availability of high quality regional EO data in near real time (NRT), EO-based crop yield forecasting has become practical enough to be applied towards operational crop yield reporting. The Canadian Crop Yield Forecaster (CCYF) is one of such modelling tool that designed to provide regional and national crop yield outlooks during and shortly after the growing season. The CCYF integrates climate, remote sensing and other earth observation information (e.g., historical yields, soil and crop maps) using a physical based soil moisture budget model and a statistical based yield forecasting model. One of the major challenges for CCYF and many other EO-based crop yield forecasting systems is to determine a proper spatial modelling scale that could be easily aggregated to various required yield reporting units, yet still retain the statistical sensitivity of crop yield to variations in climate, soil and remote sensing vegetation indices. In this study, we have compared yield modelling using CCYF at three different administrative scales, i.e. township, Census Agricultural Regions (CARs) and province for four crops (spring wheat, canola, corn and soybeans) in the agricultural regions of Manitoba, Canada. Due to the shorter available historical yield records at the township scale, different modelling scheme is applied for township scale modelling compared to the other two larger scales. The modelling at provincial scale did not capture the yield variability, while the modelling at CAR level provided reasonable results for some CARs while failed for others. The modelling at township scale captured most of the yield variability, yet its performance and implementation is restricted by the availability of the yield data at this scale.

  13. 7 CFR 1412.32 - Direct payment yield for designated oilseed and pulse crops.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Direct payment yield for designated oilseed and pulse... Establishment of Yields for Direct and Counter-Cyclical Payments § 1412.32 Direct payment yield for designated oilseed and pulse crops. (a) The direct payment yield for designated oilseeds for which a yield was...

  14. SOIL WATER USE AND GRAIN YIELD OF THREE DRYLAND CROPS UNDER DIFFERING TILLAGE SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Combining the use of drought-adapted and early maturing crops with reduced tillage practices in dryland cropping systems can increase soil water storage, water-use efficiency and crop yields. The objective of this study was to evaluate soil water use by cowpeas (Vigna unguiculata), grain sorghum [So...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  16. 7 CFR 1412.31 - Direct payment yields for covered commodities, except pulse crops.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... commodities, except pulse crops. (a) The direct payment yield for each covered commodity, except pulse crops... for covered commodities at part 1412 of this chapter in effect on January 1, 2008 (see 7 CFR part 1412... pulse crops. 1412.31 Section 1412.31 Agriculture Regulations of the Department of Agriculture...

  17. 7 CFR 1412.31 - Direct payment yields for covered commodities, except pulse crops.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... commodities, except pulse crops. (a) The direct payment yield for each covered commodity, except pulse crops... for covered commodities at part 1412 of this chapter in effect on January 1, 2008 (see 7 CFR part 1412... pulse crops. 1412.31 Section 1412.31 Agriculture Regulations of the Department of Agriculture...

  18. 7 CFR 1412.31 - Direct payment yields for covered commodities, except pulse crops.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... commodities, except pulse crops. (a) The direct payment yield for each covered commodity, except pulse crops... for covered commodities at part 1412 of this chapter in effect on January 1, 2008 (see 7 CFR part 1412... pulse crops. 1412.31 Section 1412.31 Agriculture Regulations of the Department of Agriculture...

  19. CO2 enrichment at night affects the growth and yield of common beans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some experiments to determine the crop yield increase expected with rising atmospheric carbon dioxide concentration added carbon dioxide only during the daytime, without tests of whether elevation of carbon dioxide at night affected plant growth. In this experiment, two cultivars of common bean wer...

  20. Effect of a Terminated Cover Crop and Aldicarb on Cotton Yield and Meloidogyne incognita Population Density

    PubMed Central

    Wheeler, T. A.; Leser, J. F.; Keeling, J. W.; Mullinix, B.

    2008-01-01

    Terminated small grain cover crops are valuable in light textured soils to reduce wind and rain erosion and for protection of young cotton seedlings. A three-year study was conducted to determine the impact of terminated small grain winter cover crops, which are hosts for Meloidogyne incognita, on cotton yield, root galling and nematode midseason population density. The small plot test consisted of the cover treatment as the main plots (winter fallow, oats, rye and wheat) and rate of aldicarb applied in-furrow at-plant (0, 0.59 and 0.84 kg a.i./ha) as subplots in a split-plot design with eight replications, arranged in a randomized complete block design. Roots of 10 cotton plants per plot were examined at approximately 35 days after planting. Root galling was affected by aldicarb rate (9.1, 3.8 and 3.4 galls/root system for 0, 0.59 and 0.84 kg aldicarb/ha), but not by cover crop. Soil samples were collected in mid-July and assayed for nematodes. The winter fallow plots had a lower density of M. incognita second-stage juveniles (J2) (transformed to Log10 (J2 + 1)/500 cm3 soil) than any of the cover crops (0.88, 1.58, 1.67 and 1.75 Log10(J2 + 1)/500 cm3 soil for winter fallow, oats, rye and wheat, respectively). There were also fewer M. incognita eggs at midseason in the winter fallow (3,512, 7,953, 8,262 and 11,392 eggs/500 cm3 soil for winter fallow, oats, rye and wheat, respectively). Yield (kg lint per ha) was increased by application of aldicarb (1,544, 1,710 and 1,697 for 0, 0.59 and 0.84 kg aldicarb/ha), but not by any cover crop treatments. These results were consistent over three years. The soil temperature at 15 cm depth, from when soils reached 18°C to termination of the grass cover crop, averaged 9,588, 7,274 and 1,639 centigrade hours (with a minimum threshold of 10°C), in 2005, 2006 and 2007, respectively. Under these conditions, potential reproduction of M. incognita on the cover crop did not result in a yield penalty. PMID:19259531

  1. Estimation of corn and soybeans yield using remote sensing and crop yield data in the United States

    NASA Astrophysics Data System (ADS)

    Kim, Nari; Lee, Yang-Won

    2014-10-01

    The crop yield estimation is essential for the food security and the economic development of any nation. Particularly, the United States is the world largest grain exporter, and the total amount of corn exported from the U.S. accounted for 49.2% of the world corn trade in 2010 and 2011. Thus, accurate estimation of crop yield in U.S. is very significant for not only the U.S. crop producers but also decision makers of food importing countries. Estimating the crop yield using remote sensing data plays an important role in the Agricultural Sector, and it is actively discussed and studied in many countries. This is because remote sensing can observe the large areas repetitively. Consequently, the use of various techniques based on remote sensing data is steadily increasing to accurately estimate for crop yield. Therefore, the objective of this study is to estimate the accurate yield of corn and soybeans using climate dataset of PRISM climate group and Terra/MODIS products in the United States. We construct the crop yield estimation model for the decade (2001-2010) and perform predictions and validation for 2011 and 2012.

  2. Methodology for Developing a Crop Yield Stability Map for a Field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This abstract will summarize the methodology used to develop a yield stability map for a field. We proposed that there exist yield stability patters for commercial field crop production which growers can use to optimize crop production while minimizing inputs. The methodology uses multiple years o...

  3. Impact of corn residue on yield of cool-season crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synergy between dry pea and corn can reduce the density of corn needed for optimum yield. Lower crop density may accrue an additional benefit, as after-harvest residues of corn lying on the soil surface can reduce yield of crops planted the next year. This study evaluated impact of corn residue lev...

  4. Relating Crop Yield Patterns to Terrain Attributes Under Water-Limited and Waterlogged Conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Terrain attributes derived from high-resolution digital elevation models (DEMs) can be useful for explaining spatial patterns of soil moisture and crop yields. Assuming landscape topographic controls on soil moisture variability, we correlated soil moisture and crop yield with a suite of terrain at...

  5. Correlation Between Precipitation and Crop Yield for Corn and Cotton Produced in Alabama

    NASA Technical Reports Server (NTRS)

    Hayes, Carol E.; Perkey, Donald J.

    1998-01-01

    In this study, variations in precipitation during the time of corn silking are compared to Alabama corn yields. Also, this study compares precipitation variations during bloom to Alabama cotton yield. The goal is to obtain mathematical correlations between rainfall during the crop's critical period and the crop amount harvested per acre.

  6. Soil and rainfall factors influencing yields of a dryland cropping system in Colorado

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The semi-arid Great Plains of the United States experience a large variation in crop yields due to variability in rainfall, soil, and other factors. We analyzed crop yields (24-year period) from a no-till rotation of wheat(Triticum aestivum)-corn (Zea mays L.) or sorghum[Sorghum bicolor (L.) Moench]...

  7. Book Review of the PHYSIOLOGY OF CROP YIELD by R. Hay and J. Porter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Physiology of Crop Yield by R. Hay and J. Porter (2006; Blackwell Publishing) represents a complete rewrite of An Introduction to the Physiology of Crop Yield, by R. Hay and A.J. Walker (1989). The new text emphasizes quantitative description of plant development and growth, working from a simpl...

  8. Estimation rice yield based on integration remote sensing information and crop model

    NASA Astrophysics Data System (ADS)

    Guo, Jianmao; Wang, Qi; Zheng, Tengfei; Li, Xujie; Shi, Junyi; Zhu, Jinhui

    2012-10-01

    Crop model is a powerful tool in crop growth monitoring and yield forecasting, however crop model is developed based on single point scale, due to regional differentiation、field variation and other reasons lead to input parameters and initial conditions which required by crop model simulation are hard to obtain, the application of crop model has been greatly limited in the regional scale, the introduction of remote sensing will solve this problem, remote sensing is combined with the crop model WOFOST, using the state variable retrieved by remote sensing to optimize crop model simulation, revaluing the sensitive parameters and initial conditions which needed in crop model on the region scale, in order to take the advantage of crop model in the area.This study is on the basis of adaptive adjustment and amendment of crop model WOFOST, build a winter wheat growth simulation model which is suitable for Yucheng, Shandong; Using the field experiment data calibration and validation the WOFOST model, discussed the method which combined crop simulation model and remote sensing under water stress level, using remote sensing calibrated some key processes of crop simulation or reinitialize、parameterize the crop simulation model in order to achieve the optimization model; Explored some reasonable and practical method of remote sensing information application in crop simulation at regional scale, with more research, make it possible to monitor regional crop growth and forecast the output.

  9. Rice Yield Estimation Through Assimilating Satellite Data Into a Crop Simumlation Model

    NASA Astrophysics Data System (ADS)

    Son, N. T.; Chen, C. F.; Chen, C. R.; Chang, L. Y.; Chiang, S. H.

    2016-06-01

    Rice is globally the most important food crop, feeding approximately half of the world's population, especially in Asia where around half of the world's poorest people live. Thus, advanced spatiotemporal information of rice crop yield during crop growing season is critically important for crop management and national food policy making. The main objective of this study was to develop an approach to integrate remotely sensed data into a crop simulation model (DSSAT) for rice yield estimation in Taiwan. The data assimilation was processed to integrate biophysical parameters into DSSAT model for rice yield estimation using the particle swarm optimization (PSO) algorithm. The cost function was constructed based on the differences between the simulated leaf area index (LAI) and MODIS LAI, and the optimization process starts from an initial parameterization and accordingly adjusts parameters (e.g., planting date, planting population, and fertilizer amount) in the crop simulation model. The fitness value obtained from the cost function determined whether the optimization algorithm had reached the optimum input parameters using a user-defined tolerance. The results of yield estimation compared with the government's yield statistics indicated the root mean square error (RMSE) of 11.7% and mean absolute error of 9.7%, respectively. This study demonstrated the applicability of satellite data assimilation into a crop simulation model for rice yield estimation, and the approach was thus proposed for crop yield monitoring purposes in the study region.

  10. Tradeoffs between vigor and yield for crops grown under different management systems

    NASA Astrophysics Data System (ADS)

    Simic Milas, Anita; Keller Vincent, Robert; Romanko, Matthew; Feitl, Melina; Rupasinghe, Prabha

    2016-04-01

    Remote sensing can provide an effective means for rapid and non-destructive monitoring of crop status and biochemistry. Monitoring pattern of traditional vigor algorithms generated from Landsat 8 OLI satellite data represents a robust method that can be widely used to differentiate the status of crops, as well as to monitor nutrient uptake functionality of differently treated seeds grown under different managements. This study considers 24 factorial parcels of winter wheat in 2013, corn in 2014, and soybeans in 2015, grown under four different types of agricultural management. The parcels are located at the Kellogg Biological Station, Long-Term Ecological Research site in the State of Michigan USA. At maturity, the organic crops exhibit significantly higher vigor and significantly lower yield than conventionally managed crops under different treatments. While organic crops invest in their metabolism at the expense of their yield, the conventional crops manage to increase their yield at the expense of their vigor. Landsat 8 OLI is capable of 1) differentiating the biochemical status of crops under different treatments at maturity, and 2) monitoring the tradeoff between crop yield and vigor that can be controlled by the seed treatments and proper conventional applications, with the ultimate goal of increasing food yield and food availability, and 3) distinguishing between organic and conventionally treated crops. Timing, quantity and types of herbicide applications have a great impact on early and pre-harvest vigor, maturity and yield of conventionally treated crops. Satellite monitoring using Landsat 8 is an optimal tool for coordinating agricultural applications, soil practices and genetic coding of the crop to produce higher yield as well as have early crop maturity, desirable in northern climates.

  11. Effects of land cover change on moisture availability and potential crop yield in the world’s breadbaskets

    NASA Astrophysics Data System (ADS)

    Bagley, Justin E.; Desai, Ankur R.; Dirmeyer, Paul A.; Foley, Jonathan A.

    2012-03-01

    The majority of the world’s food production capability is inextricably tied to global precipitation patterns. Changes in moisture availability—whether from changes in climate from anthropogenic greenhouse gas emissions or those induced by land cover change (LCC)—can have profound impacts on food production. In this study, we examined the patterns of evaporative sources that contribute to moisture availability over five major global food producing regions (breadbaskets), and the potential for land cover change to influence these moisture sources by altering surface evapotranspiration. For a range of LCC scenarios we estimated the impact of altered surface fluxes on crop moisture availability and potential yield using a simplified linear hydrologic model and a state-of-the-art ecosystem and crop model. All the breadbasket regions were found to be susceptible to reductions in moisture owing to perturbations in evaporative source (ES) from LCC, with reductions in moisture availability ranging from 7 to 17% leading to potential crop yield reductions of 1-17%, which are magnitudes comparable to the changes anticipated with greenhouse warming. The sensitivity of these reductions in potential crop yield to varying magnitudes of LCC was not consistent among regions. Two variables explained most of these differences: the first was the magnitude of the potential moisture availability change, with regions exhibiting greater reductions in moisture availability also tending to exhibit greater changes in potential yield; the second was the soil moisture within crop root zones. Regions with mean growing season soil moisture fractions of saturation >0.5 typically had reduced impacts on potential crop yield. Our results indicate the existence of LCC thresholds that have the capability to create moisture shortages adversely affecting crop yields in major food producing regions, which could lead to future food supply disruptions in the absence of increased irrigation or other

  12. Airborne monitoring of crop canopy temperatures for irrigation scheduling and yield prediction

    NASA Technical Reports Server (NTRS)

    Millard, J. P.; Jackson, R. D.; Reginato, R. J.; Idso, S. B.; Goettelman, R. C.; Lapado, R. L.

    1977-01-01

    The aim of the program discussed was to develop techniques for remotely measuring crop irrigation needs and predicting crop yields, with emphasis on wheat. Airborne measurements, using an IR line scanner and color IR photography, were made to evaluate the feasibility of measuring minimum and maximum (dawn and afternoon) crop temperatures to compute a parameter, termed 'stress degree day' (SDD) - a valuable indicator of crop water needs, which can be related to irrigation scheduling and yield. Crop canopy temperature measurements by airborne IR techniques revealed the superiority of thermal IR data over color IR photography. Water stress undetected in the latter technique was clearly detected in thermal imagery. Color IR photography, however, is valuable in discerning vegetation. The pseudo-colored temperature-difference images (and pseudo-colored images, reading directly in daily SDD increments) are shown to be well suited for assessing plant water status and, thus, for determining the irrigation needs and crop yield potentials.

  13. Simulation of winter wheat yield and its uncertainty band; A comparison of two crop growth models

    NASA Astrophysics Data System (ADS)

    Javad Khordadi Varamini, Mohammad; Nassiri Mahallati, Mehdi; Alizadeh, Amin

    2016-04-01

    In this study, we used the WOFOST and AquaCrop crop growth simulation models to examine crop yield responses to a set of plausible scenarios of climate change in Mashhad region, located in Ghareghom basin, northeast of Iran up to 2040. We selected winter wheat as an indicator crop. Also six AOGCMs including GFCM21, HADCM3, INCM3, IPCM4, MPEH5 and NCCCSM under A2 and B1 emission scenarios are used. LARS-WG statistical method for downscaling is utilized. In the present research, using 7-year observed crop data, the crop models were calibrated and then validated. Evaluation of WOFOST and AquaCrop models confirmed the models are able for simulating the yield of wheat grown in the study area. The results showed that average potential yield of wheat ranged from 3.43 to 8.42 and 2.76 to 6.49 ton.ha-1, in AquaCrop and WOFOST models, respectively. Finally, the uncertainty band due to the six AOGCMs for estimating crop yield is drawn and investigated. These bands show possible changes for the yield in the future period to the past one. It can be concluded the positive effects of climate warming and elevated CO2 concentrations on the production in the studied region.

  14. Monitoring Crop Yield in USA Using a Satellite-Based Climate-Variability Impact Index

    NASA Technical Reports Server (NTRS)

    Zhang, Ping; Anderson, Bruce; Tan, Bin; Barlow, Mathew; Myneni, Ranga

    2011-01-01

    A quantitative index is applied to monitor crop growth and predict agricultural yield in continental USA. The Climate-Variability Impact Index (CVII), defined as the monthly contribution to overall anomalies in growth during a given year, is derived from 1-km MODIS Leaf Area Index. The growing-season integrated CVII can provide an estimate of the fractional change in overall growth during a given year. In turn these estimates can provide fine-scale and aggregated information on yield for various crops. Trained from historical records of crop production, a statistical model is used to produce crop yield during the growing season based upon the strong positive relationship between crop yield and the CVII. By examining the model prediction as a function of time, it is possible to determine when the in-season predictive capability plateaus and which months provide the greatest predictive capacity.

  15. Potential forcing of climate changes in crops yields: Brazil and Africa perspectives

    NASA Astrophysics Data System (ADS)

    Justino, F.; Stordal, F.

    2012-12-01

    This presentation will focus on the impact of human induced climate changes on crop yields in Brazil and sub-Saharan Africa. Crop modeling simulations have been run based on regional climate models (RegCM4 and PRECIS) to serve as initial conditions to DSSAT for both current and future climate conditions. The preliminary results indicate that substantial change may be expected in the interannual variability of crop yields in Brazil but not essentially in Africa. This is attributed to substantial changes in precipitation in Brazil which are not predicted to occur in Africa. It might be noted moreover that changes in future crop productivity exhibit for both regions high spatial heterogeneity.

  16. Increasing Crop Yields in Water Stressed Countries by Combining Operations of Freshwater Reservoir and Wastewater Reclamation Plant

    NASA Astrophysics Data System (ADS)

    Bhushan, R.; Ng, T. L.

    2015-12-01

    Freshwater resources around the world are increasing in scarcity due to population growth, industrialization and climate change. This is a serious concern for water stressed countries, including those in Asia and North Africa where future food production is expected to be negatively affected by this. To address this problem, we investigate the potential of combining freshwater reservoir and wastewater reclamation operations. Reservoir water is the cheaper source of irrigation, but is often limited and climate sensitive. Treated wastewater is a more reliable alternative for irrigation, but often requires extensive further treatment which can be expensive. We propose combining the operations of a reservoir and a wastewater reclamation plant (WWRP) to augment the supply from the reservoir with reclaimed water for increasing crop yields in water stressed regions. The joint system of reservoir and WWRP is modeled as a multi-objective optimization problem with the double objective of maximizing the crop yield and minimizing total cost, subject to constraints on reservoir storage, spill and release, and capacity of the WWRP. We use the crop growth model Aquacrop, supported by The Food and Agriculture Organization of the United Nations (FAO), to model crop growth in response to water use. Aquacrop considers the effects of water deficit on crop growth stages, and from there estimates crop yield. We generate results comparing total crop yield under irrigation with water from just the reservoir (which is limited and often interrupted), and yield with water from the joint system (which has the potential of higher supply and greater reliability). We will present results for locations in India and Africa to evaluate the potential of the joint operations for improving food security in those areas for different budgets.

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

    SciTech Connect

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

    2006-01-10

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

  18. Synthetic Aperture Radar (sar) and Optical Imagery Data Fusion: Crop Yield Analysis in Southeast Asia

    NASA Astrophysics Data System (ADS)

    Parks, S. M.

    2012-08-01

    With the expanding energy crisis and rising food prices, crop yield analysis in Southeast Asia is an increasingly important topic in this region. Rice is the most important food crop in Southeast Asia and the ability to accurately predict crop yields during a growing season is useful for decision-makers, aid providers, and commercial trade organizations. The use of optical satellite image data by itself is difficult due to the almost constant cloud in many parts of Southeast Asia. However, Synthetic Aperture Radar (SAR), or SAR data, which can image the Earth's surface through cloud cover, is suitable for many agricultural purposes, such as the detection of rice fields, and the identification of different crop species. Crop yield analysis is difficult in this region due to many factors. Rice cropping systems are often characterized by the type of rice planted, the size of rice field, the sowing dates for different fields, different types of rice cropping systems from one area to another, as well as cultural practices such as sowing and transplanting. This paper will discuss the use of SAR data fused with optical imagery to improve the ability to perform crop yield analysis on rice crops in Southeast Asia.

  19. Crop yield network and its response to changes in climate system

    NASA Astrophysics Data System (ADS)

    Yokozawa, M.

    2013-12-01

    Crop failure (reduction in crop yield) due to extreme weather and climate change could lead to unstable food supply, reflecting the recent globalization in world agricultural production. Specifically, in several major production countries producing large amount of main cereal crops, wheat, maize, soybean and rice, abrupt crop failures in wide area are significantly serious for world food supply system. We examined the simultaneous changes in crop yield in USA, China and Brazil, in terms of the changes in climate system such as El Nino, La nina and so on. In this study, we defined a crop yield networks, which represent the correlation between yearly changes in crop yields and climate resources during the crop growing season in two regions. The climate resources during the crop growing season represents here the average temperature and the accumulated precipitation during the crop growing season of a target crop. As climate data, we used a reanalysis climate data JRA-25 (Japan Meteorological Agency). The yearly changes in crop yields are based on a gridded crop productivity database with a resolution of 1.125 degree in latitude/longitude (Iizumi et al. 2013). It is constructed from the agriculture statistics issued by local administrative bureau in each country, which covers the period during 1982 to 2006 (25 years). For the regions being lack of data, the data was interpolated referring to NPP values estimated by satellite data. Crop yield network is constructed as follows: (1) let DY(i,y) be negative difference in crop yield of year y from the trend yield at grid i; (2) define the correlation of the differences Cij(y) = DY(i, y) DY(j, y); (3) if Cij(y) > Q, then grids i and j are mutually linked for a threshold value Q. Links between grids make a crop yield network. It is here noted that only negative differences are taken into account because we focused on the lean year cases (i.e. yields of both grids were lower than those in the long-term trend). The arrays of

  20. Comparison between historical yield and soybean crop EVI values using correlation map

    NASA Astrophysics Data System (ADS)

    Figueiredo, G. K.; Rocha, J. V.; Lamparelli, R. A.; Brunsell, N. A.

    2012-12-01

    Timely and accurate yield estimates using remote sensing represents an important advance towards objective crop forecasting in Brazil. Vegetation index values integrated over a period have been used to generate agronomic parameters such as crop yield. Several studies showed the strong relationship between accumulated vegetation index and historical yield, once it represents crop photosynthetic activity. The main goal of this study was to create correlation maps between Modis/TERRA EVI and historical yield during the soybean crop cycle in Paraná state, Brazil, from 2000 to 2010. The soybean cycle was separated in four variables corresponding to the crop stage: emergence to maturity, emergence to flowering, flowering to maturity, flowering to the grain filling. For each variable a correlation map was created between the accumulated EVI and soybean yield at pixel level. All variables showed a good correlation, but among all of them the best correlation was the period between flowering to maturity. This happened because of exclusion of months where EVI response was low, corresponding to period of crop emergence (October and November). A percentage map of soybean crop was confronted with the correlation map to check out whether the highest correlation was corresponding to soybean pixel. On the percentage map pixels showing above 70% of soybean were selected, then on the correlation map pixels with correlation coefficients above 0.7 were selected. Within the data set 43% of pixels from the correlation map had land cover greater than or equal to 70% of soybean crop.

  1. Simulating the effects of climate and agricultural management practices on global crop yield

    NASA Astrophysics Data System (ADS)

    Deryng, D.; Sacks, W. J.; Barford, C. C.; Ramankutty, N.

    2011-06-01

    Climate change is expected to significantly impact global food production, and it is important to understand the potential geographic distribution of yield losses and the means to alleviate them. This study presents a new global crop model, PEGASUS 1.0 (Predicting Ecosystem Goods And Services Using Scenarios) that integrates, in addition to climate, the effect of planting dates and cultivar choices, irrigation, and fertilizer application on crop yield for maize, soybean, and spring wheat. PEGASUS combines carbon dynamics for crops with a surface energy and soil water balance model. It also benefits from the recent development of a suite of global data sets and analyses that serve as model inputs or as calibration data. These include data on crop planting and harvesting dates, crop-specific irrigated areas, a global analysis of yield gaps, and harvested area and yield of major crops. Model results for present-day climate and farm management compare reasonably well with global data. Simulated planting and harvesting dates are within the range of crop calendar observations in more than 75% of the total crop-harvested areas. Correlation of simulated and observed crop yields indicates a weighted coefficient of determination, with the weighting based on crop-harvested area, of 0.81 for maize, 0.66 for soybean, and 0.45 for spring wheat. We found that changes in temperature and precipitation as predicted by global climate models for the 2050s lead to a global yield reduction if planting and harvesting dates remain unchanged. However, adapting planting dates and cultivar choices increases yield in temperate regions and avoids 7-18% of global losses.

  2. Nitrate leaching, yields and carbon sequestration after noninversion tillage, catch crops, and straw retention.

    PubMed

    Hansen, E M; Munkholm, L J; Olesen, J E; Melander, B

    2015-05-01

    Crop management factors, such as tillage, rotation, and straw retention, need to be long-term to allow conclusions on effects on crop yields, nitrate leaching, and carbon sequestration. In 2002, two field experiments, each including four cash crop rotations, were established on soils with 9 and 15% clay, under temperate, coastal climate conditions. Direct drilling and harrowing to two different depths were compared to plowing with respect to yield, nitrate N leaching, and carbon sequestration. For comparison of yields across rotations, grain and seed dry matter yields for each crop were converted to grain equivalents (GE). Leaching was compared to yields by calculating yield-scaled leaching (YSL, g N kg GE), and N balances were calculated as the N input in manure minus the N output in products removed from the fields. Direct drilling reduced yields, but no effect on leaching was found. Straw retention did not significantly increase yields, nor did it reduce leaching, while fodder radish ( L.) as a catch crop was capable of reducing nitrate leaching to a low level. Thus, YSL of winter wheat ( L.) was higher than for spring barley ( L.) grown after fodder radish due to the efficient catch crop. Soil organic carbon (SOC) did not increase significantly after 7 yr of straw incorporation or noninversion tillage. There was no correlation between N balances calculated for each growing season and N leaching measured in the following percolation period. PMID:26024267

  3. Wildlife-friendly farming increases crop yield: evidence for ecological intensification.

    PubMed

    Pywell, Richard F; Heard, Matthew S; Woodcock, Ben A; Hinsley, Shelley; Ridding, Lucy; Nowakowski, Marek; Bullock, James M

    2015-10-01

    Ecological intensification has been promoted as a means to achieve environmentally sustainable increases in crop yields by enhancing ecosystem functions that regulate and support production. There is, however, little direct evidence of yield benefits from ecological intensification on commercial farms growing globally important foodstuffs (grains, oilseeds and pulses). We replicated two treatments removing 3 or 8% of land at the field edge from production to create wildlife habitat in 50-60 ha patches over a 900 ha commercial arable farm in central England, and compared these to a business as usual control (no land removed). In the control fields, crop yields were reduced by as much as 38% at the field edge. Habitat creation in these lower yielding areas led to increased yield in the cropped areas of the fields, and this positive effect became more pronounced over 6 years. As a consequence, yields at the field scale were maintained--and, indeed, enhanced for some crops--despite the loss of cropland for habitat creation. These results suggested that over a 5-year crop rotation, there would be no adverse impact on overall yield in terms of monetary value or nutritional energy. This study provides a clear demonstration that wildlife-friendly management which supports ecosystem services is compatible with, and can even increase, crop yields. PMID:26423846

  4. Sugarcane yield response to soybean double-cropping in Louisiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The interruption of continuous sugarcane plantings with a soybean (Glycine max) crop during the spring/summer fallow period between sugarcane plantings represents an economical opportunity for sugarcane growers in Louisiana. The objective of the experiment was to determine if soybeans grown in the u...

  5. Industrial oilseeds bolster "hub" crop yields when used in rotation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lack of agroecosystem diversity across the U.S. agricultural landscape is linked to several environmental issues associated with air, water, and soil quality and biodiversity. Several new industrial oilseed crops with commercial potential, offer farmers new economic opportunities and a portfolio of ...

  6. Impact of corn residue quantity on yield of following crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have observed that crop growth can be suppressed in fields where high quantities of corn residue are present on the soil surface. To examine this perceived trend, we grew dry pea, spring wheat, and red clover in two levels of corn residues, achieved by growing corn at 21,000 and 30,000 plants/ac...

  7. Technical Note: Scheduling for deficit irrigation-crop yield predictor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigators in many countries with dwindling water supplies face the prospect that they will not be able to fully irrigate their crops. In these cases, they still need to schedule their water applications to make the best economic use of available water. Major scheduling questions for deficit irrigat...

  8. Operational prediction of crop yields using MODIS data and products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Official crop progress, condition and production estimates for the United States are responsibilities of the U.S. Department of Agriculture’s, National Agricultural Statistics Service (NASS). In addition to weekly and monthly survey-based data, biweekly composite maps of the normalized difference v...

  9. Could crop height affect the wind resource at agriculturally productive wind farm sites?

    SciTech Connect

    Vanderwende, Brian; Lundquist, Julie K.

    2015-11-07

    The collocation of cropland and wind turbines in the US Midwest region introduces complex meteorological interactions that could influence both agriculture and wind-power production. Crop management practices may affect the wind resource through alterations of land-surface properties. We use the weather research and forecasting (WRF) model to estimate the impact of crop height variations on the wind resource in the presence of a large turbine array. A hypothetical wind farm consisting of 121 1.8-MW turbines is represented using the WRF model wind-farm parametrization. We represent the impact of selecting soybeans rather than maize by altering the aerodynamic roughness length in a region approximately 65 times larger than that occupied by the turbine array. Roughness lengths of 0.1 and 0.25 m represent the mature soy crop and a mature maize crop, respectively. In all but the most stable atmospheric conditions, statistically significant hub-height wind-speed increases and rotor-layer wind-shear reductions result from switching from maize to soybeans. Based on simulations for the entire month of August 2013, wind-farm energy output increases by 14 %, which would yield a significant monetary gain. Further investigation is required to determine the optimal size, shape, and crop height of the roughness modification to maximize the economic benefit and minimize the cost of such crop-management practices. As a result, these considerations must be balanced by other influences on crop choice such as soil requirements and commodity prices.

  10. Could Crop Height Affect the Wind Resource at Agriculturally Productive Wind Farm Sites?

    NASA Astrophysics Data System (ADS)

    Vanderwende, Brian; Lundquist, Julie K.

    2016-03-01

    The collocation of cropland and wind turbines in the US Midwest region introduces complex meteorological interactions that could influence both agriculture and wind-power production. Crop management practices may affect the wind resource through alterations of land-surface properties. We use the weather research and forecasting (WRF) model to estimate the impact of crop height variations on the wind resource in the presence of a large turbine array. A hypothetical wind farm consisting of 121 1.8-MW turbines is represented using the WRF model wind-farm parametrization. We represent the impact of selecting soybeans rather than maize by altering the aerodynamic roughness length in a region approximately 65 times larger than that occupied by the turbine array. Roughness lengths of 0.1 and 0.25 m represent the mature soy crop and a mature maize crop, respectively. In all but the most stable atmospheric conditions, statistically significant hub-height wind-speed increases and rotor-layer wind-shear reductions result from switching from maize to soybeans. Based on simulations for the entire month of August 2013, wind-farm energy output increases by 14 %, which would yield a significant monetary gain. Further investigation is required to determine the optimal size, shape, and crop height of the roughness modification to maximize the economic benefit and minimize the cost of such crop-management practices. These considerations must be balanced by other influences on crop choice such as soil requirements and commodity prices.

  11. Spectral Reflectance Features in Crop State and Yield Models Considering Soil and Anthropogenic Impacts

    NASA Astrophysics Data System (ADS)

    Kancheva, R.; Borisova, D.

    Agricultural models for estimating plant processes and growth require explicit information of soil, vegetation, climate, etc. Remote sensing is a tool that can be used to measure vegetation parameters for input into these models. Especially valuable are temporal data about crop state and crop development under different conditions. This paper is devoted to spectral-biophysical modeling of agricultural plants considering crop ontogenesis and dependency on soil properties (organic matter, pH-factor, nutrient accessibility) and anthropogenic impacts (fertilization, contamination). Ground-based VIS and NIR measurements have been performed to establish and statistically validate empirical relationships between crop reflectance and agronomic parameters taking into account the specific growing conditions. These relationships provide crop state assessment over the growing season. The estimated from spectral data bioparameters have been used in yield-predicting models linking crop production with plant agronomic variables. The results have been compared to the approach of using reflectance temporal behavior for yield assessment.

  12. Quantifying and mapping China's crop yield gains from sustainable and unsustainable irrigation water use

    NASA Astrophysics Data System (ADS)

    Grogan, D. S.; Zhang, F.; Glidden, S.; Wisser, D.; Proussevitch, A. A.; Li, C.; Lammers, R. B.; Frolking, S.

    2012-12-01

    About 40 - 50% of China's cropland is irrigated. We used the DNDC model to predict crop yield for ~17 crop types involved in ~28 cropping systems across China, under zero and full irrigation for each county for 1981-2000. We estimate that yield increases due to irrigation range from 0 - 100%, depending on water deficits arising from local climate and weather conditions and crop types. We used gridded water balance simulations with the UNH WBM driven by MERRA weather reconstructions for 1981-2000 to compute demand for irrigation water, and the capacity of various sources to supply that demand in each grid cell. We estimate that approximately 15% - 20% of the water needed to fulfill the country's irrigation water demand must come from unsustainable sources such as fossil groundwater. Yields using only the sustainable irrigation water capacity are calculated by weighing the DNDC zero and full irrigation yields based on the water availability results of WBM for each grid cell. Restricting irrigation water use to only sustainable sources results in a national crop yield decrease of ~20%. Irrigation water demand, unsustainable water use, and crop yield gains due to irrigation all have significant spatial variation across China. These spatial variations show that irrigation water use - sustainable and unsustainable - results in significant crop yield gains in some regions, and little to no crop yield gains in other regions. Unsustainable water use for irrigation is concentrated in the highly populated and agriculturally valuable North China Plain region, particularly Hebei, Shandong and Henan Provinces. While current plans for the South-North Water Transfer could mitigate some of the water deficit we do not expect the projected transfers to adequately supply this region with sufficient water resources to supply both the people and crops sustainably.

  13. Development of a global, gridded, and time-series crop yield dataset for four major cereal and legume crops

    NASA Astrophysics Data System (ADS)

    Iizumi, T.; Yokozawa, M.; Sakurai, G.

    2012-12-01

    Global, gridded crop yield data are essential to study impacts of climate variability and change on food production, atmosphere-soil-managed ecosystem carbon and nitrogen cycle at a global scale. However so far available data are limited to country, time-series data from the Food and Agriculture Organization (FAO) and global, gridded data in the circa 2000 from Monfreda et al. (2008). This necessitates an effort to develop a global, gridded, and time-series dataset. To that end we developed a 25-yr long (1982-2006) dataset with 1.125 x 1.125 grid size for maize, soybean, rice, and wheat by merging county statistics, FAO country statistics, and yield proxy from satellite products. Yield statistics were collected from agricultural agencies in 19 countries: those correspond to 58-95% of the global production in the 2000. The proportion for rice and wheat (58%) is less than those for maize (72%) and soybean (95%). Also net primary production (NPP) for that period was estimated crop by crop from the normalized differential vegetation index bi-monthly time series at 8-km resolution from the Global Inventory Modeling and Mapping Studies group, using the method of Los et al. (2000). When estimating yield from NPP, for each crop, we used the following six procedures: (1) for a given grid where an intended crop grows (evaluated from harvested area from Monfreda et al. (2008)), accumulate NPP time series for the whole growth period from Sacks et al. (2010), considering the temporal distribution of planting/harvesting date through an ensemble calculation of 100 different planting/harvesting date; (2) average over accumulated NPPs that locate within a given country and compute the ratio of a grid NPP against a country mean (this represents the spatial variation of yield); (3) multiply this ratio and country FAO yield year by year; (4) calculate correction coefficient that is a ratio between estimated grid yield in the 2000 and that from Monfreda et al. (2000); (5) repeat (1

  14. Using remote sensing and grid-based meteorological datasets for regional soybean crop yield prediction and crop monitoring

    NASA Astrophysics Data System (ADS)

    Mali, Preeti

    Regional crop yield estimations using crop models is a national priority due to its contributions to crop security assessment and food pricing policies. Many of these crop yield assessments are performed using time-consuming, intensive field surveys. This research was initiated to test the applicability of remote sensing and grid-based meteorological model data for providing improved and efficient predictive capabilities for crop bio-productivity. The soybean prediction model (Sinclair model) used in this research, requires daily data inputs to simulate yield which are temperature, precipitation, solar radiation, day length initialization of certain soil moisture parameters for each model run. The traditional meteorological datasets were compared with simulated South American Land Data Assimilation System (SALDAS) meteorological datasets for Sinclair model runs and for initializing soil moisture inputs. Considering the fact that grid-based meteorological data has the resolution of 1/8th of a degree, the estimations demonstrated a reasonable accuracy level and showed promise for increase in efficiency for regional level yield predictions. The research tested daily composited Normalized Difference Vegetation Index (NDVI) from Moderate Resolution Imaging Spectroradiometer (MODIS) sensor (both AQUA and TERRA platform) and simulated Visible/Infrared Imager Radiometer Suite (VIIRS) sensor product (a new sensor planned to be launched in the near future) for crop growth and development based on phenological events. The AQUA and TERRA fusion based daily MODIS NDVI was utilized to develop a planting date estimation method. The results have shown that daily MODIS composited NDVI values have the capability for enhanced monitoring of soybean crop growth and development. The method was able to predict planting date within +/-3.4 days. A geoprocessing framework for extracting data from the grid data sources was developed. Overall, this study was able to demonstrate the utility of

  15. PREDICTING SPATIAL VARIATION OF CROP YIELD ACROSS A LANDSCAPE USING AGGREGATED ENVIRONMENTAL DATA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop yield variability is an important attribute of agroecological systems. For decision-makers to make informed choices, it is necessary to understand spatial distribution of yield variability across landscapes. Spatial patterns of yield variability are associated with underlying environmental vari...

  16. Relationships between primary production and crop yields in semi-arid and arid irrigated agro-ecosystems

    NASA Astrophysics Data System (ADS)

    Jaafar, H. H.; Ahmad, F. A.

    2015-04-01

    In semi-arid areas within the MENA region, food security problems are the main problematic imposed. Remote sensing can be a promising too early diagnose food shortages and further prevent the population from famine risks. This study is aimed at examining the possibility of forecasting yield before harvest from remotely sensed MODIS-derived Enhanced Vegetation Index (EVI), Net photosynthesis (net PSN), and Gross Primary Production (GPP) in semi-arid and arid irrigated agro-ecosystems within the conflict affected country of Syria. Relationships between summer yield and remotely sensed indices were derived and analyzed. Simple regression spatially-based models were developed to predict summer crop production. The validation of these models was tested during conflict years. A significant correlation (p<0.05) was found between summer crop yield and EVI, GPP and net PSN. Results indicate the efficiency of remotely sensed-based models in predicting summer yield, mostly for cotton yields and vegetables. Cumulative summer EVI-based model can predict summer crop yield during crisis period, with deviation less than 20% where vegetables are the major yield. This approach prompts to an early assessment of food shortages and lead to a real time management and decision making, especially in periods of crisis such as wars and drought.

  17. Crop growth stress and yield reduction as detected from spectral data

    NASA Astrophysics Data System (ADS)

    Kancheva, Rumiana

    A significant amount of research is being performed to develop efficient methods for monitoring of vegetation dynamics at different scales and from different data sources. To provide distinguishable markers for agricultural crop assessment is a core task in vegetation remote sensing. This task is relevant to precision farming in order to track crop development and evaluate crop growth conditions in terms of detecting unfavorable or stress situations as well as to make yield predictions. In this paper we present some results from experiments that have been conducted over different species grown under different conditions: nutrient supply (fertilization types and rates), heavy metal pollution, soil properties. The effect of these conditions on crop growth and productivity has been studied and related to plant spectral features in a statistical manner. Crops have been characterized by key bioparameters during plant development (biomass, leaf area index, canopy cover) and by crop yield at the end of the growing season. Multispectral and multitemporal vegetation indices from ground based and airborne data have been used to quantitatively distinguish between crop state and in yield prediction models. The main pillars of the algorithm are: - development of inverse crop radiative models for estimation of crop state variables from radiometric data; - development of yield prediction models based on crop state variables with consideration of plant phenology; - current yield prediction models from crop radiometric data; - yield forecast updates from time series radiometric data; - yield prediction verification from plant biophysical models. This approach is quite suitable for implementation at local scales using airborne multispectral data with a temporal resolution in accordance with the proper for the case time-lag (crop type, ontogenesis, etc.). It has been developed for winter wheat and spring barley through ground-based experiments and has been tested and validated using

  18. African crop yield reductions due to increasingly unbalanced Nitrogen and Phosphorus consumption

    NASA Astrophysics Data System (ADS)

    van der Velde, Marijn; Folberth, Christian; Balkovič, Juraj; Ciais, Philippe; Fritz, Steffen; Janssens, Ivan A.; Obersteiner, Michael; See, Linda; Skalský, Rastislav; Xiong, Wei; Peñuealas, Josep

    2014-05-01

    The impact of soil nutrient depletion on crop production has been known for decades, but robust assessments of the impact of increasingly unbalanced nitrogen (N) and phosphorus (P) application rates on crop production are lacking. Here, we use crop response functions based on 741 FAO maize crop trials and EPIC crop modeling across Africa to examine maize yield deficits resulting from unbalanced N:P applications under low, medium, and high input scenarios, for past (1975), current, and future N:P mass ratios of respectively, 1:0.29, 1:0.15, and 1:0.05. At low N inputs (10 kg/ha), current yield deficits amount to 10% but will increase up to 27% under the assumed future N:P ratio, while at medium N inputs (50 kg N/ha), future yield losses could amount to over 40%. The EPIC crop model was then used to simulate maize yields across Africa. The model results showed relative median future yield reductions at low N inputs of 40%, and 50% at medium and high inputs, albeit with large spatial variability. Dominant low-quality soils such as Ferralsols, which are strongly adsorbing P, and Arenosols with a low nutrient retention capacity, are associated with a strong yield decline, although Arenosols show very variable crop yield losses at low inputs. Optimal N:P ratios, i.e. those where the lowest amount of applied P produces the highest yield (given N input) where calculated with EPIC to be as low as 1:0.5. Finally, we estimated the additional P required given current N inputs, and given N inputs that would allow Africa to close yield gaps (ca. 70%). At current N inputs, P consumption would have to increase 2.3-fold to be optimal, and to increase 11.7-fold to close yield gaps. The P demand to overcome these yield deficits would provide a significant additional pressure on current global extraction of P resources.

  19. African crop yield reductions due to increasingly unbalanced Nitrogen and Phosphorus consumption.

    PubMed

    van der Velde, Marijn; Folberth, Christian; Balkovič, Juraj; Ciais, Philippe; Fritz, Steffen; Janssens, Ivan A; Obersteiner, Michael; See, Linda; Skalský, Rastislav; Xiong, Wei; Peñuelas, Josep

    2014-04-01

    The impact of soil nutrient depletion on crop production has been known for decades, but robust assessments of the impact of increasingly unbalanced nitrogen (N) and phosphorus (P) application rates on crop production are lacking. Here, we use crop response functions based on 741 FAO maize crop trials and EPIC crop modeling across Africa to examine maize yield deficits resulting from unbalanced N : P applications under low, medium, and high input scenarios, for past (1975), current, and future N : P mass ratios of respectively, 1 : 0.29, 1 : 0.15, and 1 : 0.05. At low N inputs (10 kg ha(-1)), current yield deficits amount to 10% but will increase up to 27% under the assumed future N : P ratio, while at medium N inputs (50 kg N ha(-1)), future yield losses could amount to over 40%. The EPIC crop model was then used to simulate maize yields across Africa. The model results showed relative median future yield reductions at low N inputs of 40%, and 50% at medium and high inputs, albeit with large spatial variability. Dominant low-quality soils such as Ferralsols, which are strongly adsorbing P, and Arenosols with a low nutrient retention capacity, are associated with a strong yield decline, although Arenosols show very variable crop yield losses at low inputs. Optimal N : P ratios, i.e. those where the lowest amount of applied P produces the highest yield (given N input) where calculated with EPIC to be as low as 1 : 0.5. Finally, we estimated the additional P required given current N inputs, and given N inputs that would allow Africa to close yield gaps (ca. 70%). At current N inputs, P consumption would have to increase 2.3-fold to be optimal, and to increase 11.7-fold to close yield gaps. The P demand to overcome these yield deficits would provide a significant additional pressure on current global extraction of P resources. PMID:24470387

  20. The impact of climate extremes and irrigation on US crop yields

    NASA Astrophysics Data System (ADS)

    Troy, T. J.; Kipgen, C.; Pal, I.

    2015-05-01

    Climate variability and extremes are expected to increase due to climate change; this may have significant negative impacts for agricultural production. Previous work has primarily focused on the impact of mean growing season temperature and precipitation on rainfed crop yields with little work on irrigated crop yields or climate extremes and their timing. County-level crop yields and daily precipitation and temperature data are pooled to quantify the impact of climate variability and extremes on four major staple crops in the United States. Conditional density plots are used to graphically explore the relationship between climate extremes and crop yields, thereby avoiding assumptions about linearity or underlying probability distributions. Non-linear and threshold-type relationships exist between yields and both precipitation and temperature climate indices; irrigation significantly reduces the impact of all climate indices. In some cases, this occurs by shifting the threshold, such that a more extreme weather event is necessary to negatively impact yields. In other cases, irrigation essentially decouples the crop yields from climate. This work demonstrates that irrigation may be a beneficial adaptation mechanism to changes in climate extremes in coming decades.

  1. The Role of Climate Covariability on Crop Yields in the Conterminous United States.

    PubMed

    Leng, Guoyong; Zhang, Xuesong; Huang, Maoyi; Asrar, Ghassem R; Leung, L Ruby

    2016-01-01

    The covariability of temperature (T), precipitation (P) and radiation (R) is an important aspect in understanding the climate influence on crop yields. Here, we analyze county-level corn and soybean yields and observed climate for the period 1983-2012 to understand how growing-season (June, July and August) mean T, P and R influence crop yields jointly and in isolation across the CONterminous United States (CONUS). Results show that nationally averaged corn and soybean yields exhibit large interannual variability of 21% and 22%, of which 35% and 32% can be significantly explained by T and P, respectively. By including R, an additional of 5% in variability can be explained for both crops. Using partial regression analyses, we find that studies that ignore the covariability among T, P, and R can substantially overestimate the sensitivity of crop yields to a single climate factor at the county scale. Further analyses indicate large spatial variation in the relative contributions of different climate variables to the variability of historical corn and soybean yields. The structure of the dominant climate factors did not change substantially over 1983-2012, confirming the robustness of the findings, which have important implications for crop yield prediction and crop model validations. PMID:27616326

  2. Cropping sequence and nitrogen fertilization impact on surface residue, soil carbon sequestration, and crop yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information is needed on the effect of management practices on soil C storage for obtaining C credit. The effects of tillage, cropping sequence, and N fertilization were evaluated on dryland crop and surface residue C and soil organic C (SOC) at the 0-120 cm depth in a Williams loam from 2006 to 201...

  3. An energy balance approach for mapping crop waterstress and yield impacts over the Czech Republic

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a growing demand for timely, spatially distributed information regarding crop condition and water use to inform agricultural decision making and yield forecasting efforts. Remote sensing of land-surface temperature has proven valuable for mapping evapotranspiration (ET) and crop stress from...

  4. Soil attributes, soybean mineral nutrition and yield in diverse crop rotations under no-till conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of sustainable agricultural systems depends on understanding complex relationships between soil attributes, crop rotations, and crop yield. Objectives were to measure how soil chemical and physical attributes as well as soybean (Glycine max Merr.) stover dry weight and mineral concentra...

  5. 7 CFR 1412.31 - Direct payment yields for covered commodities, except pulse crops.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... for covered commodities at part 1412 of this chapter in effect on January 1, 2008 (see 7 CFR part 1412... pulse crops. 1412.31 Section 1412.31 Agriculture Regulations of the Department of Agriculture (Continued... commodities, except pulse crops. (a) The direct payment yield for each covered commodity, except pulse...

  6. Impacts of humic product application on yields of potato and other field crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercial humic products are extracts from organic materials, including immature coals (lignite, leonardite) and composted plant residues. Their application to field crops has been claimed to promote increased crop growth and economic yield, although little published evidence exists. In two indepen...

  7. Can novel management practice improve soil and environmental quality and sustain crop yield simultaneously?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known about management practices that can simultaneously improve soil and environmental quality and sustain crop yields. The effect of a combination of tillage, crop rotation, and N fertilization on soil C and N, global warming potential (GWP), greenhouse gas intensity (GHGI), and malt bar...

  8. Longer-term potato cropping system effects on soilborne diseases and tuber yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In field trials established in 2004, different 3-yr potato cropping systems focused on specific crop management goals of (SC) soil conservation, (SI) soil improvement, and (DS) disease-suppression were evaluated for their effects on soilborne diseases and tuber yield. These systems were compared to ...

  9. Yield, Grade, and Revenue of Double Cropped Green Bean and Sweet Corn with Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Double cropping green bean, (Phaseolus vulgaris L.; GB) and sweet corn (Zea mays L.; SC) with cotton (Gossypium hirsutum L.; CT) can increase the economic return but can also be at risk of crop failure due to inclement weather patterns. The objectives were to: 1) quantify the yield of GB and SC doub...

  10. Water and nutrient deficits, crop yields, and climate change

    SciTech Connect

    Reddy, K.R.; Reddy, A.R.; Hodges, H.F.; McKinion, J.M.

    1997-12-31

    Plant responses to rising CO{sub 2} environments have been largely determined in nearly optimum conditions for growth. In many studies, the nature of the experiment allowed only limited or no control of environmental factors other than [CO{sub 2}]. Here, we report the results from cotton plants grown in naturally-lit chambers in which temperature, [CO{sub 2}], water, and nutrients were controlled and varied systematically. Photosynthesis and transpiration of crop canopies were measured continuously.

  11. Salience Assignment for Multiple-Instance Data and Its Application to Crop Yield Prediction

    NASA Technical Reports Server (NTRS)

    Wagstaff, Kiri L.; Lane, Terran

    2010-01-01

    An algorithm was developed to generate crop yield predictions from orbital remote sensing observations, by analyzing thousands of pixels per county and the associated historical crop yield data for those counties. The algorithm determines which pixels contain which crop. Since each known yield value is associated with thousands of individual pixels, this is a multiple instance learning problem. Because individual crop growth is related to the resulting yield, this relationship has been leveraged to identify pixels that are individually related to corn, wheat, cotton, and soybean yield. Those that have the strongest relationship to a given crop s yield values are most likely to contain fields with that crop. Remote sensing time series data (a new observation every 8 days) was examined for each pixel, which contains information for that pixel s growth curve, peak greenness, and other relevant features. An alternating-projection (AP) technique was used to first estimate the "salience" of each pixel, with respect to the given target (crop yield), and then those estimates were used to build a regression model that relates input data (remote sensing observations) to the target. This is achieved by constructing an exemplar for each crop in each county that is a weighted average of all the pixels within the county; the pixels are weighted according to the salience values. The new regression model estimate then informs the next estimate of the salience values. By iterating between these two steps, the algorithm converges to a stable estimate of both the salience of each pixel and the regression model. The salience values indicate which pixels are most relevant to each crop under consideration.

  12. Relationship between grain crop yield potential and nitrogen response

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cereal grain fertilizer nitrogen (N) recommendations should conform to accepted theory. The objective of this study was to evaluate the relationship between yield potential (yield level) and N responsiveness in long-term winter wheat (Triticum aestivum L.) and maize (Zea mays L.) field experiments ...

  13. Prediction of crop yield in Sweden based on mesoscale meteorological analysis

    NASA Astrophysics Data System (ADS)

    Foltescu, Valentin L.

    2000-12-01

    This paper presents a prediction system for regional crop growth in Sweden, recently set up at SMHI (Swedish Meteorological and Hydrological Institute). The system includes a state-of-the-art crop growth model, WOFOST (WOrld FOod STudies) and inputs from meteorological mesoscale analysis. The simulated crops are spring barley, spring rape, oats and winter wheat, and the period of investigation is 1985-98. The simulated water-limited grain yield is used as a predictor in the yield prediction procedure. The technological time trend describing the yearly increase of the production level is accounted for as well. Yield prediction based on crop growth modelling is justified since the ability to forecast the yield is higher compared to that using the technological time trend alone. The prediction errors are of the order of 8 to 16%, with the lowest errors for winter wheat and spring barley.

  14. What aspects of future rainfall changes matter for crop yields in West Africa?

    NASA Astrophysics Data System (ADS)

    Guan, Kaiyu; Sultan, Benjamin; Biasutti, Michela; Baron, Christian; Lobell, David B.

    2015-10-01

    How rainfall arrives, in terms of its frequency, intensity, the timing and duration of rainy season, may have a large influence on rainfed agriculture. However, a thorough assessment of these effects is largely missing. This study combines a new synthetic rainfall model and two independently validated crop models (APSIM and SARRA-H) to assess sorghum yield response to possible shifts in seasonal rainfall characteristics in West Africa. We find that shifts in total rainfall amount primarily drive the rainfall-related crop yield change, with less relevance to intraseasonal rainfall features. However, dry regions (total annual rainfall below 500 mm/yr) have a high sensitivity to rainfall frequency and intensity, and more intense rainfall events have greater benefits for crop yield than more frequent rainfall. Delayed monsoon onset may negatively impact yields. Our study implies that future changes in seasonal rainfall characteristics should be considered in designing specific crop adaptations in West Africa.

  15. Dependency of global primary bioenergy crop potentials in 2050 on food systems, yields, biodiversity conservation and political stability

    PubMed Central

    Erb, Karl-Heinz; Haberl, Helmut; Plutzar, Christoph

    2012-01-01

    The future bioenergy crop potential depends on (1) changes in the food system (food demand, agricultural technology), (2) political stability and investment security, (3) biodiversity conservation, (4) avoidance of long carbon payback times from deforestation, and (5) energy crop yields. Using a biophysical biomass-balance model, we analyze how these factors affect global primary bioenergy potentials in 2050. The model calculates biomass supply and demand balances for eleven world regions, eleven food categories, seven food crop types and two livestock categories, integrating agricultural forecasts and scenarios with a consistent global land use and NPP database. The TREND scenario results in a global primary bioenergy potential of 77 EJ/yr, alternative assumptions on food-system changes result in a range of 26–141 EJ/yr. Exclusion of areas for biodiversity conservation and inaccessible land in failed states reduces the bioenergy potential by up to 45%. Optimistic assumptions on future energy crop yields increase the potential by up to 48%, while pessimistic assumptions lower the potential by 26%. We conclude that the design of sustainable bioenergy crop production policies needs to resolve difficult trade-offs such as food vs. energy supply, renewable energy vs. biodiversity conservation or yield growth vs. reduction of environmental problems of intensive agriculture. PMID:23576836

  16. Factors affecting herbicide yields in the Chesapeake Bay watershed, June 1994

    USGS Publications Warehouse

    Hainly, R.A.; Kahn, J.M.

    1996-01-01

    Median concentrations and instantaneous yields of alachlor, metolachlor, atrazine, cyanazine, and simazine were generally highest at sites in the Lower Susquehanna River Basin and in agricultural subbasins. Instantaneous herbicide yields are related to land use, hydrogeologic setting, streamflow yield, and agricultural row cropping practices. The significance of these relations may be affected by the interdependence of the factors. The percentage of basin area planted in corn is the most influential factor in the prediction of herbicide yield. Instantaneous yields of all five herbicides measured in June 1994 related poorly to averaged 199094 herbicide use. Annually averaged herbicide-use data are too general to use as a predictor for short-term herbicide yields. An evaluation of factors affecting herbicide yields could be refined with more-current land use and land cover information and a more accurate estimate of the percentage of basin area planted in corn. Factors related to herbicide yields can be used to predict herbicide yields in other basins within the Chesapeake Bay watershed and to develop an estimate of herbicide loads to Chesapeake Bay.Median concentrations and instantaneous yields of alachlor, metolachlor, atrazine, cyanazine, and simazine were generally highest at sites in the Lower Susquehanna River Basin and in agricultural subbasins. Instantaneous herbicide yields are related to land use, hydrogeologic setting, streamflow yield, and agricultural row cropping practices. The significance of these relations may be affected by the interdependence of the factors. The percentage of basin area planted in corn is the most influential factor in the prediction of herbicide yield. Instantaneous yields of all five herbicides measured in June 1994 related poorly to averaged 1990-94 herbicide use. Annually averaged herbicide-use data are too general to use as a predictor for short-term herbicide yields. An evaluation of factors affecting herbicide yields could

  17. The Potential of Five Winter-grown Crops to Reduce Root-knot Nematode Damage and Increase Yield of Tomato

    PubMed Central

    López-Pérez, Jose Antonio; Roubtsova, Tatiana; de Cara García, Miguel

    2010-01-01

    Broccoli (Brassica oleracea), carrot (Daucus carota), marigold (Tagetes patula), nematode-resistant tomato (Solanum lycopersicum), and strawberry (Fragaria ananassa) were grown for three years during the winter in a root-knot nematode (Meloidogyne incognita) infested field in Southern California. Each year in the spring, the tops of all crops were shredded and incorporated in the soil. Amendment with poultry litter was included as a sub-treatment. The soil was then covered with clear plastic for six weeks and M. incognita-susceptible tomato was grown during the summer season. Plastic tarping raised the average soil temperature at 13 cm depth by 7°C.The different winter-grown crops or the poultry litter did not affect M. incognita soil population levels. However, root galling on summer tomato was reduced by 36%, and tomato yields increased by 19% after incorporating broccoli compared to the fallow control. This crop also produced the highest amount of biomass of the five winter-grown crops. Over the three-year trial period, poultry litter increased tomato yields, but did not affect root galling caused by M. incognita. We conclude that cultivation followed by soil incorporation of broccoli reduced M. incognita damage to tomato. This effect is possibly due to delaying or preventing a portion of the nematodes to reach the host roots. We also observed that M. incognita populations did not increase under a host crop during the cool season when soil temperatures remained low (< 18°C). PMID:22736848

  18. The Impact of Changing Snowmelt Timing on Non-Irrigated Crop Yield in Idaho

    NASA Astrophysics Data System (ADS)

    Murray, E. M.; Cobourn, K.; Flores, A. N.; Pierce, J. L.; Kunkel, M. L.

    2013-12-01

    The impacts of climate change on water resources have implications for both agricultural production and grower welfare. Many mountainous regions in the western U.S. rely on snowmelt as the dominant surface water source, and in Idaho, reconstructions of spring snowmelt timing have demonstrated a trend toward earlier, more variable snowmelt dates within the past 20 years. This earlier date and increased variability in snowmelt timing have serious implications for agriculture, but there is considerable uncertainty about how agricultural impacts vary by region, crop-type, and practices like irrigation vs. dryland farming. Establishing the relationship between snowmelt timing and agricultural yield is important for understanding how changes in large-scale climatic indices (like snowmelt date) may be associated with changes in agricultural yield. This is particularly important where local practitioner behavior is influenced by historically observed relationships between these climate indices and yield. In addition, a better understanding of the influence of changes in snowmelt on non-irrigated crop yield may be extrapolated to better understand how climate change may alter biomass production in non-managed ecosystems. To investigate the impact of snowmelt date on non-irrigated crop yield, we developed a multiple linear regression model to predict historical wheat and barley yield in several Idaho counties as a function of snowmelt date, climate variables (precipitation and growing degree-days), and spatial differences between counties. The relationship between snowmelt timing and non-irrigated crop yield at the county level is strong in many of the models, but differs in magnitude and direction for the two different crops. Results show interesting spatial patterns of variability in the correlation between snowmelt timing and crop yield. In four southern counties that border the Snake River Plain and one county bordering Oregon, non-irrigated wheat and/or barley yield are

  19. Sensitivity of simulated maize crop yields to regional climate in the Southwestern United States

    NASA Astrophysics Data System (ADS)

    Kim, S.; Myoung, B.; Stack, D.; Kim, J.; Hatzopoulos, N.; Kafatos, M.

    2013-12-01

    The sensitivity of maize yield to the regional climate in the Southwestern United States (SW US) has been investigated by using a crop-yield simulation model (APSIM) in conjunction with meteorological forcings (daily minimum and maximum temperature, precipitation, and radiation) from the North American Regional Reanalysis (NARR) dataset. The primary focus of this study is to look at the effects of interannual variations of atmospheric components on the crop productivity in the SW US over the 21-year period (1991 to 2011). First of all, characteristics and performance of APSIM was examined by comparing simulated maize yields with observed yields from United States Department of Agriculture (USDA) and the leaf-area index (LAI) from MODIS satellite data. Comparisons of the simulated maize yield with the available observations show that the crop model can reasonably reproduce observed maize yields. Sensitivity tests were performed to assess the relative contribution of each climate driver to regional crop yield. Sensitivity experiments show that potential crop production responds nonlinearly to climate drivers and the yield sensitivity varied among geographical locations depending on their mean climates. Lastly, a detailed analysis of both the spatial and temporal variations of each climate driver in the regions where maize is actually grown in three states (CA, AZ, and NV) in the SW US was performed.

  20. Wildlife-friendly farming increases crop yield: evidence for ecological intensification

    PubMed Central

    Pywell, Richard F.; Heard, Matthew S.; Woodcock, Ben A.; Hinsley, Shelley; Ridding, Lucy; Nowakowski, Marek; Bullock, James M.

    2015-01-01

    Ecological intensification has been promoted as a means to achieve environmentally sustainable increases in crop yields by enhancing ecosystem functions that regulate and support production. There is, however, little direct evidence of yield benefits from ecological intensification on commercial farms growing globally important foodstuffs (grains, oilseeds and pulses). We replicated two treatments removing 3 or 8% of land at the field edge from production to create wildlife habitat in 50–60 ha patches over a 900 ha commercial arable farm in central England, and compared these to a business as usual control (no land removed). In the control fields, crop yields were reduced by as much as 38% at the field edge. Habitat creation in these lower yielding areas led to increased yield in the cropped areas of the fields, and this positive effect became more pronounced over 6 years. As a consequence, yields at the field scale were maintained—and, indeed, enhanced for some crops—despite the loss of cropland for habitat creation. These results suggested that over a 5-year crop rotation, there would be no adverse impact on overall yield in terms of monetary value or nutritional energy. This study provides a clear demonstration that wildlife-friendly management which supports ecosystem services is compatible with, and can even increase, crop yields. PMID:26423846

  1. Monitoring interannual variation in global crop yield using long-term AVHRR and MODIS observations

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoyang; Zhang, Qingyuan

    2016-04-01

    Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) data have been extensively applied for crop yield prediction because of their daily temporal resolution and a global coverage. This study investigated global crop yield using daily two band Enhanced Vegetation Index (EVI2) derived from AVHRR (1981-1999) and MODIS (2000-2013) observations at a spatial resolution of 0.05° (∼5 km). Specifically, EVI2 temporal trajectory of crop growth was simulated using a hybrid piecewise logistic model (HPLM) for individual pixels, which was used to detect crop phenological metrics. The derived crop phenology was then applied to calculate crop greenness defined as EVI2 amplitude and EVI2 integration during annual crop growing seasons, which was further aggregated for croplands in each country, respectively. The interannual variations in EVI2 amplitude and EVI2 integration were combined to correlate to the variation in cereal yield from 1982-2012 for individual countries using a stepwise regression model, respectively. The results show that the confidence level of the established regression models was higher than 90% (P value < 0.1) in most countries in the northern hemisphere although it was relatively poor in the southern hemisphere (mainly in Africa). The error in the yield predication was relatively smaller in America, Europe and East Asia than that in Africa. In the 10 countries with largest cereal production across the world, the prediction error was less than 9% during past three decades. This suggests that crop phenology-controlled greenness from coarse resolution satellite data has the capability of predicting national crop yield across the world, which could provide timely and reliable crop information for global agricultural trade and policymakers.

  2. Dryland crop yields and soil organic matter as influenced by long-term tillage and cropping sequence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Long-term management practices are needed to sustain dryland crop yields and maintain soil organic matter in the northern Great Plains. We evaluated the 21-yr effects of no-till continuous spring wheat (NTCW), spring till continuous spring wheat (STCW), fall and spring till continuous spring wheat (...

  3. Agriculture and Bioactives: Achieving Both Crop Yield and Phytochemicals

    PubMed Central

    García-Mier, Lina; Guevara-González, Ramón G.; Mondragón-Olguín, Víctor M.; Verduzco-Cuellar, Beatriz del Rocío; Torres-Pacheco, Irineo

    2013-01-01

    Plants are fundamental elements of the human diet, either as direct sources of nutrients or indirectly as feed for animals. During the past few years, the main goal of agriculture has been to increase yield in order to provide the food that is needed by a growing world population. As important as yield, but commonly forgotten in conventional agriculture, is to keep and, if it is possible, to increase the phytochemical content due to their health implications. Nowadays, it is necessary to go beyond this, reconciling yield and phytochemicals that, at first glance, might seem in conflict. This can be accomplished through reviewing food requirements, plant consumption with health implications, and farming methods. The aim of this work is to show how both yield and phytochemicals converge into a new vision of agricultural management in a framework of integrated agricultural practices. PMID:23429238

  4. Crop models capture the impacts of climate variability on corn yield

    NASA Astrophysics Data System (ADS)

    Niyogi, Dev; Liu, Xing; Andresen, Jeff; Song, Yang; Jain, Atul K.; Kellner, Olivia; Takle, Eugene S.; Doering, Otto C.

    2015-05-01

    We investigate the ability of three different crop models of varying complexity for capturing El Niño-Southern Oscillation-based climate variability impacts on the U.S. Corn Belt (1981-2010). Results indicate that crop models, irrespective of their complexity, are able to capture the impacts of climate variability on yield. Multiple-model ensemble analysis provides best results. There was no significant difference between using on-site and gridded meteorological data sets to drive the models. These results highlight the ability of using simpler crop models and gridded regional data sets for crop-climate assessments.

  5. An assessment of irrigation needs and crop yield for the United States under potential climate changes

    NASA Astrophysics Data System (ADS)

    Brumbelow, Kelly; Georgakakos, Aris

    2001-11-01

    Past assessments of climate change on U.S. agriculture have mostly focused on changes in crop yield. Few studies have included the entire conterminous United States, and few studies have assessed changing irrigation requirements. None have included the effects of changing soil moisture characteristics as determined by changing climatic forcing. This study assesses changes in irrigation requirements and crop yields for five crops in the areas of the United States where they have traditionally been grown. Physiologically based crop models are used to incorporate inputs of climate, soils, agricultural management, and drought stress tolerance. Soil moisture values from a macroscale hydrologic model run under a future climate scenario are used to initialize soil moisture content at the beginning of each growing season. Historical crop yield data are used to calibrate model parameters and to determine locally acceptable drought stress as a management parameter. Changes in irrigation demand and crop yield are assessed for both means and extremes by comparing results for atmospheric forcing close to the present climate with those for a future climate scenario. Assessments using the Canadian Center for Climate Modeling and Analysis General Circulation Model (CGCM1) indicate greater irrigation demands in the southern United States and decreased irrigation demands in the northern and western United States. Crop yields typically increase, except for winter wheat in the southern United States and corn. Variability in both irrigation demands and crop yields increases in most cases. Assessment results for the CGCM1 climate scenario are compared to those for the Hadley Centre for Climate Prediction and Research GCM (HadCM2) scenario for southwestern Georgia. The comparison shows significant differences in irrigation and yield trends, both in magnitude and in direction. The differences reflect the high forecast uncertainty of current GCMs. Nonetheless, both GCMs indicate higher

  6. An assessment of irrigation needs and crop yield for the United States under potential climate changes

    USGS Publications Warehouse

    Brumbelow, Kelly; Georgakakos, Aris P.

    2000-01-01

    Past assessments of climate change on U.S. agriculture have mostly focused on changes in crop yield. Few studies have included the entire conterminous U.S., and few studies have assessed changing irrigation requirements. None have included the effects of changing soil moisture characteristics as determined by changing climatic forcing. This study assesses changes in irrigation requirements and crop yields for five crops in the areas of the U.S. where they have traditionally been grown. Physiologically-based crop models are used to incorporate inputs of climate, soils, agricultural management, and drought stress tolerance. Soil moisture values from a macroscale hydrologic model run under a future climate scenario are used to initialize soil moisture content at the beginning of each growing season. Historical crop yield data is used to calibrate model parameters and determine locally acceptable drought stress as a management parameter. Changes in irrigation demand and crop yield are assessed for both means and extremes by comparing results for atmospheric forcing close to the present climate with those for a future climate scenario. Assessments using the Canadian Center for Climate Modeling and Analysis General Circulation Model (CGCM1) indicate greater irrigation demands in the southern U.S. and decreased irrigation demands in the northern and western U.S. Crop yields typically increase except for winter wheat in the southern U.S. and corn. Variability in both irrigation demands and crop yields increases in most cases. Assessment results for the CGCM1 climate scenario are compared to those for the Hadley Centre for Climate Prediction and Research GCM (HadCM2) scenario for southwestern Georgia. The comparison shows significant differences in irrigation and yield trends, both in magnitude and direction. The differences reflect the high forecast uncertainty of current GCMs. Nonetheless, both GCMs indicate higher variability in future climatic forcing and, consequently

  7. Digital Mapping of Soil Salinity and Crop Yield across a Coastal Agricultural Landscape Using Repeated Electromagnetic Induction (EMI) Surveys

    PubMed Central

    Yao, Rongjiang; Yang, Jingsong; Wu, Danhua; Xie, Wenping; Gao, Peng; Jin, Wenhui

    2016-01-01

    Reliable and real-time information on soil and crop properties is important for the development of management practices in accordance with the requirements of a specific soil and crop within individual field units. This is particularly the case in salt-affected agricultural landscape where managing the spatial variability of soil salinity is essential to minimize salinization and maximize crop output. The primary objectives were to use linear mixed-effects model for soil salinity and crop yield calibration with horizontal and vertical electromagnetic induction (EMI) measurements as ancillary data, to characterize the spatial distribution of soil salinity and crop yield and to verify the accuracy of spatial estimation. Horizontal and vertical EMI (type EM38) measurements at 252 locations were made during each survey, and root zone soil samples and crop samples at 64 sampling sites were collected. This work was periodically conducted on eight dates from June 2012 to May 2013 in a coastal salt-affected mud farmland. Multiple linear regression (MLR) and restricted maximum likelihood (REML) were applied to calibrate root zone soil salinity (ECe) and crop annual output (CAO) using ancillary data, and spatial distribution of soil ECe and CAO was generated using digital soil mapping (DSM) and the precision of spatial estimation was examined using the collected meteorological and groundwater data. Results indicated that a reduced model with EMh as a predictor was satisfactory for root zone ECe calibration, whereas a full model with both EMh and EMv as predictors met the requirement of CAO calibration. The obtained distribution maps of ECe showed consistency with those of EMI measurements at the corresponding time, and the spatial distribution of CAO generated from ancillary data showed agreement with that derived from raw crop data. Statistics of jackknifing procedure confirmed that the spatial estimation of ECe and CAO exhibited reliability and high accuracy. A general

  8. Digital Mapping of Soil Salinity and Crop Yield across a Coastal Agricultural Landscape Using Repeated Electromagnetic Induction (EMI) Surveys.

    PubMed

    Yao, Rongjiang; Yang, Jingsong; Wu, Danhua; Xie, Wenping; Gao, Peng; Jin, Wenhui

    2016-01-01

    Reliable and real-time information on soil and crop properties is important for the development of management practices in accordance with the requirements of a specific soil and crop within individual field units. This is particularly the case in salt-affected agricultural landscape where managing the spatial variability of soil salinity is essential to minimize salinization and maximize crop output. The primary objectives were to use linear mixed-effects model for soil salinity and crop yield calibration with horizontal and vertical electromagnetic induction (EMI) measurements as ancillary data, to characterize the spatial distribution of soil salinity and crop yield and to verify the accuracy of spatial estimation. Horizontal and vertical EMI (type EM38) measurements at 252 locations were made during each survey, and root zone soil samples and crop samples at 64 sampling sites were collected. This work was periodically conducted on eight dates from June 2012 to May 2013 in a coastal salt-affected mud farmland. Multiple linear regression (MLR) and restricted maximum likelihood (REML) were applied to calibrate root zone soil salinity (ECe) and crop annual output (CAO) using ancillary data, and spatial distribution of soil ECe and CAO was generated using digital soil mapping (DSM) and the precision of spatial estimation was examined using the collected meteorological and groundwater data. Results indicated that a reduced model with EMh as a predictor was satisfactory for root zone ECe calibration, whereas a full model with both EMh and EMv as predictors met the requirement of CAO calibration. The obtained distribution maps of ECe showed consistency with those of EMI measurements at the corresponding time, and the spatial distribution of CAO generated from ancillary data showed agreement with that derived from raw crop data. Statistics of jackknifing procedure confirmed that the spatial estimation of ECe and CAO exhibited reliability and high accuracy. A general

  9. Uncertainties in Predicting Rice Yield by Current Crop Models Under a Wide Range of Climatic Conditions

    NASA Technical Reports Server (NTRS)

    Li, Tao; Hasegawa, Toshihiro; Yin, Xinyou; Zhu, Yan; Boote, Kenneth; Adam, Myriam; Bregaglio, Simone; Buis, Samuel; Confalonieri, Roberto; Fumoto, Tamon; Gaydon, Donald; Marcaida, Manuel, III; Nakagawa, Hiroshi; Oriol, Philippe; Ruane, Alex C.; Ruget, Francoise; Singh, Balwinder; Singh, Upendra; Tang, Liang; Tao, Fulu; Wilkens, Paul; Yoshida, Hiroe; Zhang, Zhao; Bouman, Bas

    2014-01-01

    Predicting rice (Oryza sativa) productivity under future climates is important for global food security. Ecophysiological crop models in combination with climate model outputs are commonly used in yield prediction, but uncertainties associated with crop models remain largely unquantified. We evaluated 13 rice models against multi-year experimental yield data at four sites with diverse climatic conditions in Asia and examined whether different modeling approaches on major physiological processes attribute to the uncertainties of prediction to field measured yields and to the uncertainties of sensitivity to changes in temperature and CO2 concentration [CO2]. We also examined whether a use of an ensemble of crop models can reduce the uncertainties. Individual models did not consistently reproduce both experimental and regional yields well, and uncertainty was larger at the warmest and coolest sites. The variation in yield projections was larger among crop models than variation resulting from 16 global climate model-based scenarios. However, the mean of predictions of all crop models reproduced experimental data, with an uncertainty of less than 10 percent of measured yields. Using an ensemble of eight models calibrated only for phenology or five models calibrated in detail resulted in the uncertainty equivalent to that of the measured yield in well-controlled agronomic field experiments. Sensitivity analysis indicates the necessity to improve the accuracy in predicting both biomass and harvest index in response to increasing [CO2] and temperature.

  10. Climate-Induced Changes in Year-to-Year Variations in Yields of Major Crops

    NASA Astrophysics Data System (ADS)

    Iizumi, T.; Sakurai, G.; Ramankutty, N.

    2014-12-01

    Incidences of climatic extremes and associated crop failures in major food-producing regions have implications for commodity prices and generate concerns for national governments and commercial entities in import-dependent countries. While recent changes in temperature and precipitation extremes are evident, their impacts on the year-to-year variability of yield remain unclear. Here we present a global assessment of the impacts of recent climate change on year-to-year variations in yields of major crops using a global dataset of historical yields recently developed by merging satellite product and country-level crop statistics. We found that crop yield variability, in a large portion (24-53%) of the global harvested area, decreased from the earlier decade (1982—1993) to the later decade (1994—2005). However, yield variability also increased in a substantial portion (9—17%) of the harvested area. The changes in yield variability across 20—31% of the harvested area could be reasonably explained by changes in an agro-climatic index. Our findings reveal that climate change in the last two decades has led to more unstable yields in some regions. However, climate change has reduced yield variability in many more regions of the world. This suggests complex influences of climate change and agronomic technology on yield variability.

  11. The past impact of climate change on the yield of major crops

    NASA Astrophysics Data System (ADS)

    Sakurai, G.; Iizumi, T.; Nishimori, M.; Okada, M.; Yokozawa, M.

    2014-12-01

    Understanding the relationship between climate change and crop production is of paramount importance for food security. Previous statistical analyses of historical data have revealed the important impact of temperature increases on past crop yields. However, the direct effect of the [CO2] increase, known as CO2 fertilization effect, is difficult to estimate by simple statistical analysis because the average atmospheric [CO2] does not vary widely over space and time. Moreover, it is also difficult to estimate each climatic effect on crop yields with completely removing correlation among climatic factors. Although non-statistical approaches using process-based crop models may overcome these problems, the results of simple simulation studies may be misleading because of the uncertainty of the model parameters. In the present study, we applied a Bayesian statistical approach to estimate the parameters of a basic process-based model of crop growth (PRYSBI-2) and the past effect of each climatic factor on yields of major crops. The spatial variability of model parameters was considered by estimating the posterior distribution of the parameters from historical yield data by using the Markov-chain Monte Carlo (MCMC) method. The datasets of maize, soybean, rice, and wheat yields during 1982-2006 with a spatial resolution of 1.125° × 1.125° were used for this purpose (Iizumi et al. 2013). The posterior distributions of model parameters were estimated for each spatial grid with 30 000 MCMC steps of 7 chains. Using this model, we produced maps of the estimated past impact of each climatic factor (including CO2 effect) on crop yields (see Figure for the effect of temperature changes on maize yield as an example). The results suggested large variations of the impact of the change in average temperature on major crop yields. The results also suggested a large impact of CO2 increase on C3 crops such as soybean, rice, and wheat. In some regions, the positive impact of CO2

  12. Trading carbon for food: Global comparison of carbon stocks vs. crop yields on agricultural land

    PubMed Central

    West, Paul C.; Gibbs, Holly K.; Monfreda, Chad; Wagner, John; Barford, Carol C.; Carpenter, Stephen R.; Foley, Jonathan A.

    2010-01-01

    Expanding croplands to meet the needs of a growing population, changing diets, and biofuel production comes at the cost of reduced carbon stocks in natural vegetation and soils. Here, we present a spatially explicit global analysis of tradeoffs between carbon stocks and current crop yields. The difference among regions is striking. For example, for each unit of land cleared, the tropics lose nearly two times as much carbon (∼120 tons·ha−1 vs. ∼63 tons·ha−1) and produce less than one-half the annual crop yield compared with temperate regions (1.71 tons·ha−1·y−1 vs. 3.84 tons·ha−1·y−1). Therefore, newly cleared land in the tropics releases nearly 3 tons of carbon for every 1 ton of annual crop yield compared with a similar area cleared in the temperate zone. By factoring crop yield into the analysis, we specify the tradeoff between carbon stocks and crops for all areas where crops are currently grown and thereby, substantially enhance the spatial resolution relative to previous regional estimates. Particularly in the tropics, emphasis should be placed on increasing yields on existing croplands rather than clearing new lands. Our high-resolution approach can be used to determine the net effect of local land use decisions. PMID:21041633

  13. Crop yield monitoring based on a photosynthetic sterility model using NDVI and daily meteorological data

    NASA Astrophysics Data System (ADS)

    Kaneko, Daijiro

    2007-10-01

    This research is intended to develop a model to monitor rice yields using the photosynthetic yield index, which integrates solar radiation and air temperature effects on photosynthesis and grain-filling from heading to ripening. Monitoring crop production using remotely sensed and daily meteorological data can provide an important early warning of poor crop production to Asian countries, with their still-growing populations, and also to Japan, which produces insufficient grain for its population. The author improved a photosynthesis-and-sterility-based crop production CPI index to crop yield index CYI, which estimates rice yields, in place of the crop situation index CSI. The CSI gives a percentage of rice yields compared to normal annual production. The model calculates photosynthesis rates including biomass effects, lowtemperature sterility, and high-temperature injury by incorporating: solar radiation, effective air temperature, normalized difference vegetation index NDVI, and the effect of temperature on photosynthesis by grain plant leaves. The method is based on routine observation data, enabling automated monitoring of crop production at arbitrary regions without special observations. The method aims to quantity grain production at an early stage to raise the alarm in Asian countries, which are facing climate fluctuation through this century of global warming.

  14. Elevated CO2 and the Sensitivity of Simulated Crop Yield to Variability in Climate

    NASA Astrophysics Data System (ADS)

    King, A. W.; Absar, M.; Surendran Nair, S.; Preston, B. L.

    2013-12-01

    It is known that the response of crop yields to elevated carbon dioxide (CO2) concentrations ('CO2 fertilization') can vary with climatic conditions (e.g., precipitation and soil moisture). Likewise, the sensitivity of crop yield to changes in climate may vary with atmospheric CO2 concentrations. The latter is an important consideration when extrapolating crop sensitivities derived from historical climate variability to a future world with higher levels of atmospheric CO2. Here we report on our investigation of how climate sensitivity of model simulated crop yield is influenced by rising and elevated CO2. Initial results from the EPIC crop model for simulated cotton yield at a site in southeastern Texas show very little if any difference in sensitivity to annual precipitation with static versus rising CO2 concentrations. These model results are consistent with experimental results from the Maricopa, Arizona Free Air CO2 Enrichment (FACE) experiment in which there was little or no difference in the productivity response of cotton under ample versus limited supplies of water. This contrasts with experimental results for wheat and sorghum, especially sorghum, in which the response to elevated CO2 was larger when water supply was limited. We report on the interaction between CO2 and the sensitivity of yield to climate with comparisons for different crops, between the EPIC and DSSAT crop models, across different indices of climate change, and between wet and dry climatic domains of the southern United States of America. This investigation is part of our ongoing effort better understand the sensitivity of crop yield to climate in order to inform regional integrated assessment modeling and considerations of adaption to climate change in the Gulf Coastal region of the southern United States.

  15. Development of Crop Yield Estimation Method by Applying Seasonal Climate Prediction in Asia-Pacific Region

    NASA Astrophysics Data System (ADS)

    Shin, Y.; Lee, E.

    2015-12-01

    Under the influence of recent climate change, abnormal weather condition such as floods and droughts has issued frequently all over the world. The occurrence of abnormal weather in major crop production areas leads to soaring world grain prices because it influence the reduction of crop yield. Development of crop yield estimation method is important means to accommodate the global food crisis caused by abnormal weather. However, due to problems with the reliability of the seasonal climate prediction, application research on agricultural productivity has not been much progress yet. In this study, it is an object to develop long-term crop yield estimation method in major crop production countries worldwide using multi seasonal climate prediction data collected by APEC Climate Center. There are 6-month lead seasonal predictions produced by six state-of-the-art global coupled ocean-atmosphere models(MSC_CANCM3, MSC_CANCM4, NASA, NCEP, PNU, POAMA). First of all, we produce a customized climate data through temporal and spatial downscaling methods for use as a climatic input data to the global scale crop model. Next, we evaluate the uncertainty of climate prediction by applying multi seasonal climate prediction in the crop model. Because rice is the most important staple food crop in the Asia-Pacific region, we assess the reliability of the rice yields using seasonal climate prediction for main rice production countries. RMSE(Root Mean Squire Error) and TCC(Temporal Correlation Coefficient) analysis is performed in Asia-Pacific countries, major 14 rice production countries, to evaluate the reliability of the rice yield according to the climate prediction models. We compare the rice yield data obtained from FAOSTAT and estimated using the seasonal climate prediction data in Asia-Pacific countries. In addition, we show that the reliability of seasonal climate prediction according to the climate models in Asia-Pacific countries where rice cultivation is being carried out.

  16. Spatial modeling of contemporary crop yields in China under sustainable and unsustainable water use scenarios

    NASA Astrophysics Data System (ADS)

    Grogan, D. S.; Zhang, F.; Li, C.; Frolking, S.

    2011-12-01

    Irrigated agriculture is an important part of China's population and economic growth. Currently, water needed to irrigate crops can be drawn from surface runoff, streams, reservoirs, renewable groundwater, or fossil groundwater. Fossil groundwater is not sustainable over long time periods, and therefore regions that rely on this source for irrigation water could face water shortages in the future, and may already be experiencing water stress today. This study uses two models, one to calculate water balance and the other to simulate crop yields, to address the question: how much unsustainable water is currently used for irrigation in China, and by how much would the use of only sustainable water reduce crop yields? The amount of sustainable water available for irrigation is determined using the WBMplus model. This model uses precipitation and temperature drivers, along with gridded data of soils, cropping, and irrigation, to simulate soil moisture, potential evapotranspiration, surface runoff, stream flow, and reservoir storage, in 30 min grid cells. The model also computes demand for irrigation water, and the capacity of various sources to supply that demand in each grid cell. The DNDC model, which has been evaluated against crop yield in a number of studies in China, is used to predict crop yield for ~50 crop types involved in ~100 cropping systems across China, under zero and full irrigation for each grid cell. Yields using only the sustainable irrigation water capacity will be calculated by weighing the zero and full irrigation yields based on the water availability results of WBMplus for each grid cell. With this methodology, we estimate how national-scale food production would be changed by limiting agricultural water use.

  17. Effect of Climate-Induced Change in Crop Yields on Emigration: The Case of Mexico

    NASA Astrophysics Data System (ADS)

    Oppenheimer, M.; Krueger, A. B.; Feng, S.

    2009-05-01

    Researchers have suggested several channels through which future global warming could trigger mass migration across country borders. This paper examines one of them by focusing on the effect of climate- induced crop failures on out-migration. Using data from Mexico, we identify and estimate elasticity of emigration with respect to changes in crop yield, which sheds light on the possible magnitudes of migrant flows for other areas of the world under different climate change scenarios. We choose Mexico as the study object as it is by far the largest migrant-sending country, with an estimated number of emigrants living in the United States to be well over 10 million. In addition, over 20% of Mexico population directly relies on the agricultural sector, which is heavily dependent on climate. For example, the prolonged drought from 1996 to 1998 in northern Mexico resulted in mass crop failures and the death of livestock. Historically, farmers have been using emigration as an adaptation strategy to cope with crop yield reductions. We first examine the relationship between corn yields and climate variables for the period of 1980-2000, using state-level data. We find significant positive effects of annual precipitation and annual average temperature, but a negative effect of summer temperature on corn yields. The effects of both annual and summer temperatures are also nonlinear. Our analyses of other crops such as wheat yield very similar results. Using Mexico Census micro data, we calculate the number of emigrants from each state for the periods of 1990-1995 and 1995-2000. We then regress changes in the number of emigrants on changes in crop yields, instrumented by changes in temperatures and precipitation. Our preferred specification gives an elasticity of -4, which suggests that a 25% reduction in crop yields would double the number of emigrants. The null hypothesis of no effect is rejected at the 5% significance level.

  18. Assessing the impact of long-term cultivation on runoff, pollutant load, and crop yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past century, agriculture had detrimental impacts on soil and water quality revealed by increased surface runoff and non-point source pollution. In this study, we estimated the impact of long-term agriculture on surface runoff, sediment yield, atrazine load, and crop yields. Soil samples we...

  19. Impact of different cover crop residues and shank types on no-till tomato yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A three year experiment with no-till tomatoes was conducted in Cullman, AL (2006 to 2008) to determine the effect of plastic mulch (control), rye and crimson clover cover crops, and different subsoiler shanks on no–till tomato yield. In 2006 and 2008, plastic cover provided higher yield compared wit...

  20. Evaluating high resolution SPOT 5 satellite imagery for crop yield estimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High resolution satellite imagery has the potential for mapping within-field variability in crop growth and yield. This study examined SPOT 5 multispectral imagery for estimating grain sorghum yield. A SPOT 5 image with 10-m spatial resolution and four spectral bands (green, red, near-infrared, and ...

  1. MODELING THE IMPACT OF OZONE X DROUGHT INTERACTIONS ON REGIONAL CROP YIELDS (JOURNAL VERSION)

    EPA Science Inventory

    The influence of soil moisture stress on crop sensitivity to O3 was evaluated for corn, cotton, soybean, and wheat grown in the United States by using yield forecasting models to estimate the influence of soil moisture deficits on regional yield and a previously developed model t...

  2. Use of aggregated environment data to predict spatial variation of crop yields across a landscape

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop yield variability is effected by environmental heterogeneity at various scales. “Scaling-up” of locally-derived process-based models has not been universally successful in accurately modeling patterns of yield association with environmental characteristics at broader spatial scales. Use of re...

  3. Impacts of elevated atmospheric CO2 on nutrient content and yield of important food crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the many ways that climate change may affect human health is by altering the nutrient content of food crops. However, previous attempts to study the effects of increased atmospheric CO2 on crop nutrition have been limited by small sample sizes and/or artificial growing conditions. Here we p...

  4. Estimated winter wheat yield from crop growth predicted by LANDSAT

    NASA Technical Reports Server (NTRS)

    Kanemasu, E. T.

    1977-01-01

    An evapotranspiration and growth model for winter wheat is reported. The inputs are daily solar radiation, maximum temperature, minimum temperature, precipitation/irrigation and leaf area index. The meteorological data were obtained from National Weather Service while LAI was obtained from LANDSAT multispectral scanner. The output provides daily estimates of potential evapotranspiration, transpiration, evaporation, soil moisture (50 cm depth), percentage depletion, net photosynthesis and dry matter production. Winter wheat yields are correlated with transpiration and dry matter accumulation.

  5. Yield Trends Are Insufficient to Double Global Crop Production by 2050.

    PubMed

    Ray, Deepak K; Mueller, Nathaniel D; West, Paul C; Foley, Jonathan A

    2013-01-01

    Several studies have shown that global crop production needs to double by 2050 to meet the projected demands from rising population, diet shifts, and increasing biofuels consumption. Boosting crop yields to meet these rising demands, rather than clearing more land for agriculture has been highlighted as a preferred solution to meet this goal. However, we first need to understand how crop yields are changing globally, and whether we are on track to double production by 2050. Using ∼2.5 million agricultural statistics, collected for ∼13,500 political units across the world, we track four key global crops-maize, rice, wheat, and soybean-that currently produce nearly two-thirds of global agricultural calories. We find that yields in these top four crops are increasing at 1.6%, 1.0%, 0.9%, and 1.3% per year, non-compounding rates, respectively, which is less than the 2.4% per year rate required to double global production by 2050. At these rates global production in these crops would increase by ∼67%, ∼42%, ∼38%, and ∼55%, respectively, which is far below what is needed to meet projected demands in 2050. We present detailed maps to identify where rates must be increased to boost crop production and meet rising demands. PMID:23840465

  6. Evaluating the synchronicity in yield variations of staple crops at global scale

    NASA Astrophysics Data System (ADS)

    Yokozawa, M.

    2014-12-01

    Reflecting the recent globalization trend in world commodity market, several major production countries are producing large amount of staple crops, especially, maize and soybean. Thus, simultaneous crop failure (abrupt reduction in crop yield, lean year) due to extreme weather and/or climate change could lead to unstable food supply. This study try to examine the synchronicity in yield variations of staple crops at global scale. We use a gridded crop yields database, which includes the historical year-to-year changes in staple crop yields with a spatial resolution of 1.125 degree in latitude/longitude during a period of 1982-2006 (Iizumi et al. 2013). It has been constructed based on the agriculture statistics issued by local administrative bureaus in each country. For the regions being lack of data, an interpolation was conducted to obtain the values referring to the NPP estimates from satellite data as well as FAO country yield. For each time series of the target crop yield, we firstly applied a local kernel regression to represent the long-term trend component. Next, the deviations of yearly yield from the long-term trend component were defined as ΔY(i, y) in year y at grid i. Then, the correlation of deviation between grids i and j in year y is defined as Cij(y) = ΔY(i, y) ΔY(j, y). In addition, Pij = <ΔY(i, y) ΔY(j, y)> represents the time-averaged correlation of deviation between grids i and j. Bracket <...> means the time average operation over 25 years (1982-2006). As the results, figures show the time changes in the number of grid pairs, in which both the deviation are negative. It represent the time changes in ratio of the grid pairs where both crop yields synchronically decreased to the total grid pairs. The years denoted by arrows in the figures indicate the case that all the ratios of three country pairs (i.e. China-USA, USA-Brazil and Brazil-China) are relatively larger (>0.6 for soybean and >0.5 for maize). This suggests that the reductions in

  7. Effects of Break Crops on Yield and Grain Protein Concentration of Barley in a Boreal Climate

    PubMed Central

    Zou, Ling; Yli-Halla, Markku; Stoddard, Frederick L.; Mäkelä, Pirjo S. A.

    2015-01-01

    Rotation with dicotyledonous crops to break cereal monoculture has proven to be beneficial to successive cereals. In two fields where the soil had been subjected to prolonged, continuous cereal production, two 3-year rotation trials were established. In the first year, faba bean, turnip rape and barley were grown, as first crops, in large blocks and their residues tilled into the soil after harvest. In the following year, barley, buckwheat, caraway, faba bean, hemp and white lupin were sown, as second crops, in each block and incorporated either at flowering stage (except barley) or after harvest. In the third year, barley was grown in all plots and its yield and grain protein concentration were determined. Mineral N in the plough layer was determined two months after incorporation of crops and again before sowing barley in the following year. The effect of faba bean and turnip rape on improving barley yields and grain protein concentration was still detectable two years after they were grown. The yield response of barley was not sensitive to the growth stage of second crops when they were incorporated, but was to different second crops, showing clear benefits averaging 6-7% after white lupin, faba bean and hemp but no benefit from caraway or buckwheat. The effect of increased N in the plough layer derived from rotation crops on barley yields was minor. Incorporation of plants at flowering stage slightly increased third-year barley grain protein concentration but posed a great potential for N loss compared with incorporation of crop residues after harvest, showing the value of either delayed incorporation or using catch crops. PMID:26076452

  8. Effects of Break Crops on Yield and Grain Protein Concentration of Barley in a Boreal Climate.

    PubMed

    Zou, Ling; Yli-Halla, Markku; Stoddard, Frederick L; Mäkelä, Pirjo S A

    2015-01-01

    Rotation with dicotyledonous crops to break cereal monoculture has proven to be beneficial to successive cereals. In two fields where the soil had been subjected to prolonged, continuous cereal production, two 3-year rotation trials were established. In the first year, faba bean, turnip rape and barley were grown, as first crops, in large blocks and their residues tilled into the soil after harvest. In the following year, barley, buckwheat, caraway, faba bean, hemp and white lupin were sown, as second crops, in each block and incorporated either at flowering stage (except barley) or after harvest. In the third year, barley was grown in all plots and its yield and grain protein concentration were determined. Mineral N in the plough layer was determined two months after incorporation of crops and again before sowing barley in the following year. The effect of faba bean and turnip rape on improving barley yields and grain protein concentration was still detectable two years after they were grown. The yield response of barley was not sensitive to the growth stage of second crops when they were incorporated, but was to different second crops, showing clear benefits averaging 6-7% after white lupin, faba bean and hemp but no benefit from caraway or buckwheat. The effect of increased N in the plough layer derived from rotation crops on barley yields was minor. Incorporation of plants at flowering stage slightly increased third-year barley grain protein concentration but posed a great potential for N loss compared with incorporation of crop residues after harvest, showing the value of either delayed incorporation or using catch crops. PMID:26076452

  9. Mutually beneficial pollinator diversity and crop yield outcomes in small and large farms.

    PubMed

    Garibaldi, Lucas A; Carvalheiro, Luísa G; Vaissière, Bernard E; Gemmill-Herren, Barbara; Hipólito, Juliana; Freitas, Breno M; Ngo, Hien T; Azzu, Nadine; Sáez, Agustín; Åström, Jens; An, Jiandong; Blochtein, Betina; Buchori, Damayanti; Chamorro García, Fermín J; Oliveira da Silva, Fabiana; Devkota, Kedar; Ribeiro, Márcia de Fátima; Freitas, Leandro; Gaglianone, Maria C; Goss, Maria; Irshad, Mohammad; Kasina, Muo; Pacheco Filho, Alípio J S; Kiill, Lucia H Piedade; Kwapong, Peter; Parra, Guiomar Nates; Pires, Carmen; Pires, Viviane; Rawal, Ranbeer S; Rizali, Akhmad; Saraiva, Antonio M; Veldtman, Ruan; Viana, Blandina F; Witter, Sidia; Zhang, Hong

    2016-01-22

    Ecological intensification, or the improvement of crop yield through enhancement of biodiversity, may be a sustainable pathway toward greater food supplies. Such sustainable increases may be especially important for the 2 billion people reliant on small farms, many of which are undernourished, yet we know little about the efficacy of this approach. Using a coordinated protocol across regions and crops, we quantify to what degree enhancing pollinator density and richness can improve yields on 344 fields from 33 pollinator-dependent crop systems in small and large farms from Africa, Asia, and Latin America. For fields less than 2 hectares, we found that yield gaps could be closed by a median of 24% through higher flower-visitor density. For larger fields, such benefits only occurred at high flower-visitor richness. Worldwide, our study demonstrates that ecological intensification can create synchronous biodiversity and yield outcomes. PMID:26798016

  10. NASA Earth Science Research Results for Improved Regional Crop Yield Prediction

    NASA Astrophysics Data System (ADS)

    Mali, P.; O'Hara, C. G.; Shrestha, B.; Sinclair, T. R.; G de Goncalves, L. G.; Salado Navarro, L. R.

    2007-12-01

    National agencies such as USDA Foreign Agricultural Service (FAS), Production Estimation and Crop Assessment Division (PECAD) work specifically to analyze and generate timely crop yield estimates that help define national as well as global food policies. The USDA/FAS/PECAD utilizes a Decision Support System (DSS) called CADRE (Crop Condition and Data Retrieval Evaluation) mainly through an automated database management system that integrates various meteorological datasets, crop and soil models, and remote sensing data; providing significant contribution to the national and international crop production estimates. The "Sinclair" soybean growth model has been used inside CADRE DSS as one of the crop models. This project uses Sinclair model (a semi-mechanistic crop growth model) for its potential to be effectively used in a geo-processing environment with remote-sensing-based inputs. The main objective of this proposed work is to verify, validate and benchmark current and future NASA earth science research results for the benefit in the operational decision making process of the PECAD/CADRE DSS. For this purpose, the NASA South American Land Data Assimilation System (SALDAS) meteorological dataset is tested for its applicability as a surrogate meteorological input in the Sinclair model meteorological input requirements. Similarly, NASA sensor MODIS products is tested for its applicability in the improvement of the crop yield prediction through improving precision of planting date estimation, plant vigor and growth monitoring. The project also analyzes simulated Visible/Infrared Imager/Radiometer Suite (VIIRS, a future NASA sensor) vegetation product for its applicability in crop growth prediction to accelerate the process of transition of VIIRS research results for the operational use of USDA/FAS/PECAD DSS. The research results will help in providing improved decision making capacity to the USDA/FAS/PECAD DSS through improved vegetation growth monitoring from high

  11. Simulating large-scale crop yield by using perturbed-parameter ensemble method

    NASA Astrophysics Data System (ADS)

    Iizumi, T.; Yokozawa, M.; Sakurai, G.; Nishimori, M.

    2010-12-01

    Toshichika Iizumi, Masayuki Yokozawa, Gen Sakurai, Motoki Nishimori Agro-Meteorology Division, National Institute for Agro-Environmental Sciences, Japan Abstract One of concerning issues of food security under changing climate is to predict the inter-annual variation of crop production induced by climate extremes and modulated climate. To secure food supply for growing world population, methodology that can accurately predict crop yield on a large scale is needed. However, for developing a process-based large-scale crop model with a scale of general circulation models (GCMs), 100 km in latitude and longitude, researchers encounter the difficulties in spatial heterogeneity of available information on crop production such as cultivated cultivars and management. This study proposed an ensemble-based simulation method that uses a process-based crop model and systematic parameter perturbation procedure, taking maize in U.S., China, and Brazil as examples. The crop model was developed modifying the fundamental structure of the Soil and Water Assessment Tool (SWAT) to incorporate the effect of heat stress on yield. We called the new model PRYSBI: the Process-based Regional-scale Yield Simulator with Bayesian Inference. The posterior probability density function (PDF) of 17 parameters, which represents the crop- and grid-specific features of the crop and its uncertainty under given data, was estimated by the Bayesian inversion analysis. We then take 1500 ensemble members of simulated yield values based on the parameter sets sampled from the posterior PDF to describe yearly changes of the yield, i.e. perturbed-parameter ensemble method. The ensemble median for 27 years (1980-2006) was compared with the data aggregated from the county yield. On a country scale, the ensemble median of the simulated yield showed a good correspondence with the reported yield: the Pearson’s correlation coefficient is over 0.6 for all countries. In contrast, on a grid scale, the correspondence

  12. Building a statistical emulator for prediction of crop yield response to climate change: a global gridded panel data set approach

    NASA Astrophysics Data System (ADS)

    Mistry, Malcolm; De Cian, Enrica; Wing, Ian Sue

    2015-04-01

    There is widespread concern that trends and variability in weather induced by climate change will detrimentally affect global agricultural productivity and food supplies. Reliable quantification of the risks of negative impacts at regional and global scales is a critical research need, which has so far been met by forcing state-of-the-art global gridded crop models with outputs of global climate model (GCM) simulations in exercises such as the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP)-Fastrack. Notwithstanding such progress, it remains challenging to use these simulation-based projections to assess agricultural risk because their gridded fields of crop yields are fundamentally denominated as discrete combinations of warming scenarios, GCMs and crop models, and not as model-specific or model-averaged yield response functions of meteorological shifts, which may have their own independent probability of occurrence. By contrast, the empirical climate economics literature has adeptly represented agricultural responses to meteorological variables as reduced-form statistical response surfaces which identify the crop productivity impacts of additional exposure to different intervals of temperature and precipitation [cf Schlenker and Roberts, 2009]. This raises several important questions: (1) what do the equivalent reduced-form statistical response surfaces look like for crop model outputs, (2) do they exhibit systematic variation over space (e.g., crop suitability zones) or across crop models with different characteristics, (3) how do they compare to estimates based on historical observations, and (4) what are the implications for the characterization of climate risks? We address these questions by estimating statistical yield response functions for four major crops (maize, rice, wheat and soybeans) over the historical period (1971-2004) as well as future climate change scenarios (2005-2099) using ISIMIP-Fastrack data for five GCMs and seven crop models

  13. Scale-dependent effects of landscape composition and configuration on natural enemy diversity, crop herbivory, and yields.

    PubMed

    Martin, Emily A; Seo, Bumsuk; Park, Chan-Ryul; Reineking, Björn; Steffan-Dewenter, Ingolf

    2016-03-01

    (1) Land-use intensification in agricultural landscapes has led to changes in the way habitats and resources are distributed in space. Pests and their natural enemies are influenced by these changes, and by the farming intensity of crop fields. However, it is unknown whether the composition of landscapes (amount and diversity of land cover types) or their configuration (spatial arrangement of cover types) are more important for natural enemy diversity, and how they impact crop damage and yields. In addition, effects of interactions between local farming practices (organic vs. conventional) and landscape variables are unclear. (2) Here, we make use of a data set where landscape composition and configuration were uncorrelated across multiple spatial scales. Natural enemies, crop damage, and yields were sampled in 35 organic and conventional crop fields. Out of seven broad natural enemy taxa, five were positively affected by a complex landscape configuration. In contrast, only carabids were positively affected by the amount of seminatural habitat around fields. Increasing diversity of land cover types had positive effects on some, but negative effects on other taxa. Effect sizes varied among taxa but increased with increasing spatial scale, defined by circular areas of increasing radius around fields. (3) The diversity of aerial, but not of ground-dwelling enemies was higher in fields under organic than conventional management. Interactions of local and landscape variables were important for birds, but not other enemies. Bird richness was higher in organic fields in simple landscapes, but not in landscapes with complex configuration or high land cover diversity. (4) Crop damage decreased with landscape diversity, but increased in conventional fields with complex configuration. Yields increased with both parameters in conventional fields only, and were higher on average in organic compared to conventional fields. Enemy diversity was positively related to crop damage

  14. Broadcast applications of acetic acid: Crop injury and onion yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The organic herbicides for sweet onions (Allium cepa L.) are limited to non-selective materials, such as corn gluten meal and vinegar. Research in Oklahoma has shown that corn gluten meal can be an affective early season pre-emergence herbicide for onion transplants, but once the residual impact of...

  15. 7 CFR 1412.34 - Submitting production evidence for establishing direct payment yields for oilseeds and pulse crops.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... oilseeds and pulse crops. (a)(1) Reports of production evidence must be submitted when the owner elects to... designated oilseeds for which a yield was not established by September 30, 2007, and for pulse crops must be... direct payment yields for oilseeds and pulse crops. 1412.34 Section 1412.34 Agriculture Regulations...

  16. 7 CFR 1412.34 - Submitting production evidence for establishing direct payment yields for oilseeds and pulse crops.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... oilseeds and pulse crops. (a)(1) Reports of production evidence must be submitted when the owner elects to... designated oilseeds for which a yield was not established by September 30, 2007, and for pulse crops must be... direct payment yields for oilseeds and pulse crops. 1412.34 Section 1412.34 Agriculture Regulations...

  17. 7 CFR 1412.34 - Submitting production evidence for establishing direct payment yields for oilseeds and pulse crops.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... oilseeds and pulse crops. (a)(1) Reports of production evidence must be submitted when the owner elects to... designated oilseeds for which a yield was not established by September 30, 2007, and for pulse crops must be... direct payment yields for oilseeds and pulse crops. 1412.34 Section 1412.34 Agriculture Regulations...

  18. Biomass production of 12 winter cereal cover crop cultivars and their effect on subsequent no-till corn yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crops can improve the sustainability and resilience of corn and soybean production systems. However, there have been isolated reports of corn yield reductions following winter rye cover crops. Although there are many possible causes of corn yield reductions following winter cereal cover crops,...

  19. North–South divide: contrasting impacts of climate change on crop yields in Scotland and England

    PubMed Central

    Butterworth, Michael H.; Semenov, Mikhail A.; Barnes, Andrew; Moran, Dominic; West, Jonathan S.; Fitt, Bruce D. L.

    2010-01-01

    Effects of climate change on productivity of agricultural crops in relation to diseases that attack them are difficult to predict because they are complex and nonlinear. To investigate these crop–disease–climate interactions, UKCIP02 scenarios predicting UK temperature and rainfall under high- and low-CO2 emission scenarios for the 2020s and 2050s were combined with a crop-simulation model predicting yield of fungicide-treated winter oilseed rape and with a weather-based regression model predicting severity of phoma stem canker epidemics. The combination of climate scenarios and crop model predicted that climate change will increase yield of fungicide-treated oilseed rape crops in Scotland by up to 0.5 t ha−1 (15%). In contrast, in southern England the combination of climate scenarios, crop, disease and yield loss models predicted that climate change will increase yield losses from phoma stem canker epidemics to up to 50 per cent (1.5 t ha−1) and greatly decrease yield of untreated winter oilseed rape. The size of losses is predicted to be greater for winter oilseed rape cultivars that are susceptible than for those that are resistant to the phoma stem canker pathogen Leptosphaeria maculans. Such predictions illustrate the unexpected, contrasting impacts of aspects of climate change on crop–disease interactions in agricultural systems in different regions. PMID:19447817

  20. Proximity to forest edge does not affect crop production despite pollen limitation

    PubMed Central

    Chacoff, Natacha P; Aizen, Marcelo A; Aschero, Valeria

    2008-01-01

    A decline in pollination function has been linked to agriculture expansion and intensification. In northwest Argentina, pollinator visits to grapefruit, a self-compatible but pollinator-dependent crop, decline by approximately 50% at 1 km from forest edges. We evaluated whether this decrease in visitation also reduces the pollination service in this crop. We analysed the quantity and quality of pollen deposited on stigmas, and associated limitation of fruit production at increasing distances (edge: 10, 100, 500 and 1000 m) from the remnants of Yungas forest. We also examined the quantitative and qualitative efficiency of honeybees as pollen vectors. Pollen receipt and pollen tubes in styles decreased with increasing distance from forest edge; however, this decline did not affect fruit production. Supplementation of natural pollen with self- and cross-pollen revealed that both pollen quantity and quality limited fruit production. Despite pollen limitation, honeybees cannot raise fruit production because they often do not deposit sufficient high-quality pollen per visit to elicit fruit development. However, declines in visitation frequency well below seven visits during a flower's lifespan could decrease production beyond current yields. In this context, the preservation of forest remnants, which act as pollinator sources, could contribute to resilience in crop production. Like wild plants, pollen limitation of the yield among animal-pollinated crops may be common and indicative not only of pollinator scarcity, but also of poor pollination quality, whereby pollinator efficiency, rather than just abundance, can play a broader role than previously appreciated. PMID:18230596

  1. Characterizing spatial and temporal variability of crop yield caused by climate and irrigation in the North China Plain

    NASA Astrophysics Data System (ADS)

    Chen, Chao; Baethgen, Walter E.; Wang, Enli; Yu, Qiang

    2011-12-01

    Grain yields of wheat and maize were obtained from national statistics and simulated with an agricultural system model to investigate the effects of historical climate variability and irrigation on crop yield in the North China Plain (NCP). Both observed and simulated yields showed large temporal and spatial variability due to variations in climate and irrigation supply. Wheat yield under full irrigation (FI) was 8 t ha-1 or higher in 80% of seasons in the north, it ranged from 7 to 10 t ha-1 in 90% of seasons in central NCP, and less than 9 t ha-1 in 85% of seasons in the south. Reduced irrigation resulted in increased crop yield variability. Wheat yield under supplemental irrigation, i.e., to meet only 50% of irrigation water requirement [supplemental irrigation (SI)] ranged from 2.7 to 8.8 t ha-1 with the maximum frequency of seasons having the range of 4-6 t ha-1 in the north, 4-7 t ha-1 in central NCP, and 5-8 t ha-1 in the south. Wheat yield under no irrigation (NI) was lower than 1 t ha-1 in about 50% of seasons. Considering the NCP as a whole, simulated maize yield under FI ranged from 3.9 to 11.8 t ha-1 with similar frequency distribution in the range of 6-11.8 t ha-1 with the interval of 2 t ha-1. It ranged from 0 to 11.8 t ha-1, uniformly distributed into the range of 4-10 t ha-1 under SI, and NI. The results give an insight into the levels of regional crop production affected by climate and water management strategies.

  2. Simulation of crop yield variability by improved root-soil-interaction modelling

    NASA Astrophysics Data System (ADS)

    Duan, X.; Gayler, S.; Priesack, E.

    2009-04-01

    Understanding the processes and factors that govern the within-field variability in crop yield has attached great importance due to applications in precision agriculture. Crop response to environment at field scale is a complex dynamic process involving the interactions of soil characteristics, weather conditions and crop management. The numerous static factors combined with temporal variations make it very difficult to identify and manage the variability pattern. Therefore, crop simulation models are considered to be useful tools in analyzing separately the effects of change in soil or weather conditions on the spatial variability, in order to identify the cause of yield variability and to quantify the spatial and temporal variation. However, tests showed that usual crop models such as CERES-Wheat and CERES-Maize were not able to quantify the observed within-field yield variability, while their performance on crop growth simulation under more homogeneous and mainly non-limiting conditions was sufficent to simulate average yields at the field-scale. On a study site in South Germany, within-field variability in crop growth has been documented since years. After detailed analysis and classification of the soil patterns, two site specific factors, the plant-available-water and the O2 deficiency, were considered as the main causes of the crop growth variability in this field. Based on our measurement of root distribution in the soil profile, we hypothesize that in our case the insufficiency of the applied crop models to simulate the yield variability can be due to the oversimplification of the involved root models which fail to be sensitive to different soil conditions. In this study, the root growth model described by Jones et al. (1991) was adapted by using data of root distributions in the field and linking the adapted root model to the CERES crop model. The ability of the new root model to increase the sensitivity of the CERES crop models to different enviromental

  3. Crop modelling as a tool to separate the influence of the soil and weather on crop yields

    NASA Astrophysics Data System (ADS)

    Mathe-Gaspar, Gabriella; Fodor, Nandor; Pokovai, Klara; Kovacs, Geza Janos

    The yield of traditional food and feed crops in a given habitat is controlled by the soil and weather conditions as the main environmental factors. In real world it is not possible to segregate the influences of the soil and the weather on the crop production. Using simulation models there are ways to analyse the effects of the changes of soil characteristics or weather elements separately. The role of different soil characteristics can be studied in a way that the first run is considered as a control, then one of the soil characteristics is changed within a realistic range while all the other soil factors and weather inputs are left original. This way all the soil characteristic and weather elements can be changed one by one or different combinations of them can be used as input series. A more practical approach is when the role of local soils and weather are compared by a series of runs applying observed weather data from different years and real soil profiles from different fields of the selected farm. The results of the simulation can be evaluated from many different aspects: biomass or yield production, vulnerability to nitrate leaching or denitrification and profitability. In this study real Hungarian soil and weather scenarios were used that are significantly different from one another. The two main crops of Hungary were used: maize and wheat plus field pea as an addition. Pea is known as a sensitive crop to weather. 4M-simulation package was used as a modelling tool. Our group at RISSAC based on CERES and CROPGRO models has developed it. The results showed that the weather differences caused more significant changes in yields then soil differences though soils could moderate the effects of the extreme weather scenarios. The measure of reactions is meaningfully different depending on the species and cultivars. Analysis of separated effects of soil and weather factors has not only theoretical and methodological importance, but useful for the practice, too

  4. Crop modelling as a tool to separate the influences of the soil and weather on crop yields

    NASA Astrophysics Data System (ADS)

    Mathe-Gaspar, G.; Fodor, N.; Pokovai, K.; Kovacs, G. J.

    2003-04-01

    The yield of traditional food and feed crops in a given habitat is controlled by the soil and weather conditions as the main environmental factors. In real world it is not possible to segregate the influences of the soil and the weather on the crop production. Using simulation models there are ways to analyse the effects of the changes of soil characteristics or weather elements separately. The role of different soil characteristics can be studied in a way that the first run is considered as a control, then one of the soil characteristics is changed within a realistic range while all the other soil factors and weather inputs are left original. This way all the soil characteristic and weather elements can be changed one by one or different combinations of them can be used as input series. A more practical approach is when the role of local soils and weather are compared by a series of runs applying observed weather data from different years and real soil profiles from different fields of the selected farm. The results of the simulation can be evaluated from many different aspects: biomass or yield production, vulnerability to nitrate leaching or denitrification and profitability. In this study real Hungarian soil and weather scenarios were used that are significantly different from one another. The two main crops of Hungary were used: maize and wheat plus field pea as an addition. Pea is known as a sensitive crop to weather. 4M-simulation package was used as a modelling tool. Our group at RISSAC based on CERES and CROPGRO models has developed it. The results showed that the weather differences caused more significant changes in yields then soil differences though soils could moderate the effects of the extreme weather scenarios. The measure of reactions is meaningfully different depending on the species and cultivars. Analysis of separated effects of soil and weather factors has not only theoretical and methodological importance, but useful for the practice, too

  5. Yield Trends Are Insufficient to Double Global Crop Production by 2050

    PubMed Central

    Ray, Deepak K.; Mueller, Nathaniel D.; West, Paul C.; Foley, Jonathan A.

    2013-01-01

    Several studies have shown that global crop production needs to double by 2050 to meet the projected demands from rising population, diet shifts, and increasing biofuels consumption. Boosting crop yields to meet these rising demands, rather than clearing more land for agriculture has been highlighted as a preferred solution to meet this goal. However, we first need to understand how crop yields are changing globally, and whether we are on track to double production by 2050. Using ∼2.5 million agricultural statistics, collected for ∼13,500 political units across the world, we track four key global crops—maize, rice, wheat, and soybean—that currently produce nearly two-thirds of global agricultural calories. We find that yields in these top four crops are increasing at 1.6%, 1.0%, 0.9%, and 1.3% per year, non-compounding rates, respectively, which is less than the 2.4% per year rate required to double global production by 2050. At these rates global production in these crops would increase by ∼67%, ∼42%, ∼38%, and ∼55%, respectively, which is far below what is needed to meet projected demands in 2050. We present detailed maps to identify where rates must be increased to boost crop production and meet rising demands. PMID:23840465

  6. Linkages among climate change, crop yields and Mexico–US cross-border migration

    PubMed Central

    Feng, Shuaizhang; Krueger, Alan B.; Oppenheimer, Michael

    2010-01-01

    Climate change is expected to cause mass human migration, including immigration across international borders. This study quantitatively examines the linkages among variations in climate, agricultural yields, and people's migration responses by using an instrumental variables approach. Our method allows us to identify the relationship between crop yields and migration without explicitly controlling for all other confounding factors. Using state-level data from Mexico, we find a significant effect of climate-driven changes in crop yields on the rate of emigration to the United States. The estimated semielasticity of emigration with respect to crop yields is approximately −0.2, i.e., a 10% reduction in crop yields would lead an additional 2% of the population to emigrate. We then use the estimated semielasticity to explore the potential magnitude of future emigration. Depending on the warming scenarios used and adaptation levels assumed, with other factors held constant, by approximately the year 2080, climate change is estimated to induce 1.4 to 6.7 million adult Mexicans (or 2% to 10% of the current population aged 15–65 y) to emigrate as a result of declines in agricultural productivity alone. Although the results cannot be mechanically extrapolated to other areas and time periods, our findings are significant from a global perspective given that many regions, especially developing countries, are expected to experience significant declines in agricultural yields as a result of projected warming. PMID:20660749

  7. Nitrogen and Water Stress Impact on Hard Red Spring Wheat Crop Reflectance, Yield and Grain Quality

    NASA Astrophysics Data System (ADS)

    Reese, C. L.; Clay, D. E.; Beck, D.; Clay, S. A.; Seielstad, G.

    2007-12-01

    Water and nitrogen stress impact hard red spring wheat (Triticum aestivum) crop reflectance, yield and grain quality. To minimize yield losses from nitrogen (N) and water stress, it is essential to apply appropriate N in relation to water stress. The objective of this experiment was to determine the influence of N and water stress on hard red spring wheat crop reflectance, yield, and grain quality. Complete randomized block experiments were conducted in 2003, 2004 and 2004 in dryland and irrigated fields at three locations in central South Dakota. Treatments consisted of N rates and N application at different growth stages. Nitrogen fertilizer rates ranged from 0 to 200 kg ha-1. Nitrogen fertilizer application times were (1) planting; (2) planting and tillering (Feekes 2 -3) or (3) tillering (Feekes 2 -3). Reflectance data was collected using a Cropscan and a CropCircle radiometer. Reflectance data was collected at bare soil, tillering (Feekes 2-3) and flag leaf (Feekes 9-10). Carbon 13 isotopic discrimination (Ä) was used to determine yield loss to nitrogen or water stress. Reflectance data was compared to yield and Ä values or grain quality and Ä values. Correlation of crop reflectance (measured at the different growth stages and by the different radiometers) with yield loss to nitrogen or water and grain quality will be presented. Information presented will be used to make corrective nitrogen treatments and improve marketing decisions as related to grain quality.

  8. Satellite Estimates of Crop Area and Maize Yield in Zambia's Agricultural Districts

    NASA Astrophysics Data System (ADS)

    Azzari, G.; Lobell, D. B.

    2015-12-01

    Predicting crop yield and area from satellite is a valuable tool to monitor different aspects of productivity dynamics and food security. In Sub-Saharan Africa, where the agricultural landscape is complex and dominated by smallholder systems, such dynamics need to be investigated at the field scale. We leveraged the large data pool and computational power of Google Earth Engine to 1) generate 30 m resolution cover maps of selected provinces of Zambia, 2) estimate crop area, and 3) produce yearly maize yield maps using the recently developed SCYM (Scalable satellite-based Crop Yield Mapper) algorithm. We will present our results and their validation against a ground survey dataset collected yearly by the Zambia Ministry of Agriculture from about 12,500 households.

  9. Uncertainty in soil data can outweigh climate impact signals in global crop yield simulations

    PubMed Central

    Folberth, Christian; Skalský, Rastislav; Moltchanova, Elena; Balkovič, Juraj; Azevedo, Ligia B.; Obersteiner, Michael; van der Velde, Marijn

    2016-01-01

    Global gridded crop models (GGCMs) are increasingly used for agro-environmental assessments and estimates of climate change impacts on food production. Recently, the influence of climate data and weather variability on GGCM outcomes has come under detailed scrutiny, unlike the influence of soil data. Here we compare yield variability caused by the soil type selected for GGCM simulations to weather-induced yield variability. Without fertilizer application, soil-type-related yield variability generally outweighs the simulated inter-annual variability in yield due to weather. Increasing applications of fertilizer and irrigation reduce this variability until it is practically negligible. Importantly, estimated climate change effects on yield can be either negative or positive depending on the chosen soil type. Soils thus have the capacity to either buffer or amplify these impacts. Our findings call for improvements in soil data available for crop modelling and more explicit accounting for soil variability in GGCM simulations. PMID:27323866

  10. Uncertainty in soil data can outweigh climate impact signals in global crop yield simulations

    NASA Astrophysics Data System (ADS)

    Folberth, Christian; Skalský, Rastislav; Moltchanova, Elena; Balkovič, Juraj; Azevedo, Ligia B.; Obersteiner, Michael; van der Velde, Marijn

    2016-06-01

    Global gridded crop models (GGCMs) are increasingly used for agro-environmental assessments and estimates of climate change impacts on food production. Recently, the influence of climate data and weather variability on GGCM outcomes has come under detailed scrutiny, unlike the influence of soil data. Here we compare yield variability caused by the soil type selected for GGCM simulations to weather-induced yield variability. Without fertilizer application, soil-type-related yield variability generally outweighs the simulated inter-annual variability in yield due to weather. Increasing applications of fertilizer and irrigation reduce this variability until it is practically negligible. Importantly, estimated climate change effects on yield can be either negative or positive depending on the chosen soil type. Soils thus have the capacity to either buffer or amplify these impacts. Our findings call for improvements in soil data available for crop modelling and more explicit accounting for soil variability in GGCM simulations.

  11. Uncertainty in soil data can outweigh climate impact signals in global crop yield simulations.

    PubMed

    Folberth, Christian; Skalský, Rastislav; Moltchanova, Elena; Balkovič, Juraj; Azevedo, Ligia B; Obersteiner, Michael; van der Velde, Marijn

    2016-01-01

    Global gridded crop models (GGCMs) are increasingly used for agro-environmental assessments and estimates of climate change impacts on food production. Recently, the influence of climate data and weather variability on GGCM outcomes has come under detailed scrutiny, unlike the influence of soil data. Here we compare yield variability caused by the soil type selected for GGCM simulations to weather-induced yield variability. Without fertilizer application, soil-type-related yield variability generally outweighs the simulated inter-annual variability in yield due to weather. Increasing applications of fertilizer and irrigation reduce this variability until it is practically negligible. Importantly, estimated climate change effects on yield can be either negative or positive depending on the chosen soil type. Soils thus have the capacity to either buffer or amplify these impacts. Our findings call for improvements in soil data available for crop modelling and more explicit accounting for soil variability in GGCM simulations. PMID:27323866

  12. Identifying opportunities to reduce excess nitrogen in croplands while maintaining current crop yields

    NASA Astrophysics Data System (ADS)

    West, P. C.; Mueller, N. D.; Foley, J. A.

    2011-12-01

    Use of synthetic nitrogen fertilizer has greatly contributed to the increased crop yields brought about by the Green Revolution. Unfortunately, it also has also contributed to substantial excess nitrogen in the environment. Application of excess nitrogen not only is a waste of energy and other resources used to produce, transport and apply it, it also pollutes aquatic ecosystems and has led to the development of more than 200 hypoxic-or "dead"-zones in coastal areas around the world. How can we decrease use of excess nitrogen without compromising crop yields? To help address this challenge, our study (1) quantified hot spots of excess nitrogen, and (2) estimated how much nitrogen reduction is possible in these areas while still maintaining yields. We estimated excess nitrogen for major crops using a mass balance approach and global spatial data sets of crop area and yield, fertilizer application rates, and nitrogen deposition. Hot spots of excess nitrogen were identified by quantifying the smallest area within large river basins that contributed 25% and 50% of the total load within each basin. Nitrogen reduction scenarios were developed using a yield response model to estimate nitrogen application rates needed to maintain current yields. Our research indicated that excess nitrogen is concentrated in very small portions of croplands within river basins, with 25% of the total nitrogen load in each basin from ~10% of the cropland, and 50% of the total nitrogen load in each basin from ~25% of the cropland. Targeting reductions in application rates in these hot spots can allow us to maintain current crop yields while greatly reducing nitrogen loading to coastal areas and creating the opportunity to reallocate resources to boost yields on nitrogen-limited croplands elsewhere.

  13. A meta-analysis of crop yield under climate change and adaptation

    NASA Astrophysics Data System (ADS)

    Challinor, A. J.; Watson, J.; Lobell, D. B.; Howden, S. M.; Smith, D. R.; Chhetri, N.

    2014-04-01

    Feeding a growing global population in a changing climate presents a significant challenge to society. The projected yields of crops under a range of agricultural and climatic scenarios are needed to assess food security prospects. Previous meta-analyses have summarized climate change impacts and adaptive potential as a function of temperature, but have not examined uncertainty, the timing of impacts, or the quantitative effectiveness of adaptation. Here we develop a new data set of more than 1,700 published simulations to evaluate yield impacts of climate change and adaptation. Without adaptation, losses in aggregate production are expected for wheat, rice and maize in both temperate and tropical regions by 2 °C of local warming. Crop-level adaptations increase simulated yields by an average of 7-15%, with adaptations more effective for wheat and rice than maize. Yield losses are greater in magnitude for the second half of the century than for the first. Consensus on yield decreases in the second half of the century is stronger in tropical than temperate regions, yet even moderate warming may reduce temperate crop yields in many locations. Although less is known about interannual variability than mean yields, the available data indicate that increases in yield variability are likely.

  14. Heterogeneous global crop yield response to biochar: a meta-regression analysis

    NASA Astrophysics Data System (ADS)

    Crane-Droesch, Andrew; Abiven, Samuel; Jeffery, Simon; Torn, Margaret S.

    2013-12-01

    Biochar may contribute to climate change mitigation at negative cost by sequestering photosynthetically fixed carbon in soil while increasing crop yields. The magnitude of biochar’s potential in this regard will depend on crop yield benefits, which have not been well-characterized across different soils and biochars. Using data from 84 studies, we employ meta-analytical, missing data, and semiparametric statistical methods to explain heterogeneity in crop yield responses across different soils, biochars, and agricultural management factors, and then estimate potential changes in yield across different soil environments globally. We find that soil cation exchange capacity and organic carbon were strong predictors of yield response, with low cation exchange and low carbon associated with positive response. We also find that yield response increases over time since initial application, compared to non-biochar controls. High reported soil clay content and low soil pH were weaker predictors of higher yield response. No biochar parameters in our dataset—biochar pH, percentage carbon content, or temperature of pyrolysis—were significant predictors of yield impacts. Projecting our fitted model onto a global soil database, we find the largest potential increases in areas with highly weathered soils, such as those characterizing much of the humid tropics. Richer soils characterizing much of the world’s important agricultural areas appear to be less likely to benefit from biochar.

  15. Influence of springtime North Atlantic Oscillation on crops yields in Northeast China

    NASA Astrophysics Data System (ADS)

    Zhou, Mengzi; Wang, Huijun; Yang, Song; Fan, Ke

    2013-12-01

    Forecasting grain production is of strategic importance in considerations of climate change and growing population. Here we show that the springtime North Atlantic Oscillation (NAO) is significantly correlated to the year-to-year increment of maize and rice yield in Northeast China (NEC). The physical mechanism for this relationship was investigated. Springtime NAO can induce sea surface temperature anomalies (SSTAs) in the North Atlantic, which display a tripole pattern and are similar to the empirical mode pattern in spring. The spring Atlantic SSTA pattern that could persists to summer, can trigger a high-level tropospheric Rossby wave response in the Eurasia continent, resulting in atmospheric circulation anomalies over the Siberia-Mongolia region, which is unfavorable (favorable) for cold surges that affect NEC. Weaker (stronger) cold surges can accordingly reduce (increase) cloud amount, resulting in an increase (a decrease) in daily maximum temperature and a decrease (an increase) in daily minimum temperature, thereby leading to an increase (a decrease) in diurnal temperature range. And summer-mean daily minimum temperature and diurnal temperature range are most significantly related to the NEC crop yields.

  16. Could crop height affect the wind resource at agriculturally productive wind farm sites?

    DOE PAGESBeta

    Vanderwende, Brian; Lundquist, Julie K.

    2015-11-07

    The collocation of cropland and wind turbines in the US Midwest region introduces complex meteorological interactions that could influence both agriculture and wind-power production. Crop management practices may affect the wind resource through alterations of land-surface properties. We use the weather research and forecasting (WRF) model to estimate the impact of crop height variations on the wind resource in the presence of a large turbine array. A hypothetical wind farm consisting of 121 1.8-MW turbines is represented using the WRF model wind-farm parametrization. We represent the impact of selecting soybeans rather than maize by altering the aerodynamic roughness length inmore » a region approximately 65 times larger than that occupied by the turbine array. Roughness lengths of 0.1 and 0.25 m represent the mature soy crop and a mature maize crop, respectively. In all but the most stable atmospheric conditions, statistically significant hub-height wind-speed increases and rotor-layer wind-shear reductions result from switching from maize to soybeans. Based on simulations for the entire month of August 2013, wind-farm energy output increases by 14 %, which would yield a significant monetary gain. Further investigation is required to determine the optimal size, shape, and crop height of the roughness modification to maximize the economic benefit and minimize the cost of such crop-management practices. As a result, these considerations must be balanced by other influences on crop choice such as soil requirements and commodity prices.« less

  17. Genetic mechanisms of abiotic stress tolerance that translate to crop yield stability.

    PubMed

    Mickelbart, Michael V; Hasegawa, Paul M; Bailey-Serres, Julia

    2015-04-01

    Crop yield reduction as a consequence of increasingly severe climatic events threatens global food security. Genetic loci that ensure productivity in challenging environments exist within the germplasm of crops, their wild relatives and species that are adapted to extreme environments. Selective breeding for the combination of beneficial loci in germplasm has improved yields in diverse environments throughout the history of agriculture. An effective new paradigm is the targeted identification of specific genetic determinants of stress adaptation that have evolved in nature and their precise introgression into elite varieties. These loci are often associated with distinct regulation or function, duplication and/or neofunctionalization of genes that maintain plant homeostasis. PMID:25752530

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

    PubMed

    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. PMID:26710622

  19. Simulating yield response of rice to salinity stress with the AquaCrop model.

    PubMed

    Mondal, M Shahjahan; Saleh, Abul Fazal M; Razzaque Akanda, Md Abdur; Biswas, Sujit K; Md Moslehuddin, Abu Zofar; Zaman, Sinora; Lazar, Attila N; Clarke, Derek

    2015-06-01

    The FAO AquaCrop model has been widely applied throughout the world to simulate crop responses to deficit water applications. However, its application to saline conditions is not yet reported, though saline soils are common in coastal areas. In this study, we parameterized and tested AquaCrop to simulate rice yield under different salinity regimes. The data and information required in the model were collected through a field experiment at the Bangladesh Agricultural Research Institute, Gazipur. The experiment was conducted with the BRRI Dhan28, a popular boro rice variety in Bangladesh, with five levels of saline water irrigation, three replicates for each level. In addition, field monitoring was carried out at Satkhira in the southwest coastal region of Bangladesh to collect data and information based on farmers' practices and to further validate the model. The results indicated that the AquaCrop model with most of its default parameters could replicate the variation of rice yield with the variation of salinity reasonably well. The root mean square error and mean absolute error of the model yield were only 0.12 t per ha and 0.03 t per ha, respectively. The crop response versus soil salinity stress curve was found to be convex in shape with a lower threshold of 2 dS m(-1), an upper threshold of 10 dS m(-1) and a shape factor of 2.4. As the crop production system in the coastal belt of Bangladesh has become vulnerable to climate induced sea-level rise and the consequent increase in water and soil salinity, the AquaCrop would be a useful tool in assessing the potential impact of these future changes as well as other climatic parameters on rice yield in the coastal region. PMID:25865338

  20. PERUN system and its application for assessing the crop yield potential of the Czech Republic

    NASA Astrophysics Data System (ADS)

    Dubrovsky, M.; Zalud, Z.; Eitzinger, J.; Trnka, M.; Semeradova, D.

    2003-04-01

    The main purpose of the first version of the computer system PERUN, which has been developed in 2001-2002 (presented in EGS 2002), is the probabilistic seasonal crop yield forecasting for a given site. The system is based on the crop growth model WOFOST (version 7, slightly modified) and the six-variate version of the stochastic weather generator Met&Roll. The system is now being enhanced to allow assessment of the crop yield potential of a larger area. As this assessment requires a great amount of meteorological, pedological and crop data to be gathered, but these data are not yet all available to the authors, the presentation will rather focus on the methodological aspects and the results of the sensitivity analysis. The presentation will consist of the following points: (i) Overview of the PERUN system. The results of the validation experiments (spring barley and winter wheat at selected Czech locations) will be presented, too. (ii) Methodology used for a spatial assessment. The assessment is based on integrating model crop yields simulated at multiple sub-regions with region-specific climatic and pedological conditions. The input daily weather series are produced by the stochastic generator. The multi-year crop model simulation is performed for each sub-region to assess the mean and variability of the model yields. (iii) Sensitivity of the regional crop production potential to uncertainties in selected input characteristics: crop cultivar, soil type, hydrological characteristics (e.g. amount of available water at the beginning of the simulation), and climatic conditions (e.g temperature, precipitation). In assessing sensitivity to climate, the climatic characteristics will be varied within the range of values typical for the territory of the Czech Republic. The crops applied in the analysis are spring barley and winter wheat. Acknowledgement: The system PERUN has been developed within the frame of project QC1316 sponsored by the Czech National Agency for

  1. Crop monitoring & yield forecasting system based on Synthetic Aperture Radar (SAR) and process-based crop growth model: Development and validation in South and South East Asian Countries

    NASA Astrophysics Data System (ADS)

    Setiyono, T. D.

    2014-12-01

    Accurate and timely information on rice crop growth and yield helps governments and other stakeholders adapting their economic policies and enables relief organizations to better anticipate and coordinate relief efforts in the wake of a natural catastrophe. Such delivery of rice growth and yield information is made possible by regular earth observation using space-born Synthetic Aperture Radar (SAR) technology combined with crop modeling approach to estimate yield. Radar-based remote sensing is capable of observing rice vegetation growth irrespective of cloud coverage, an important feature given that in incidences of flooding the sky is often cloud-covered. The system allows rapid damage assessment over the area of interest. Rice yield monitoring is based on a crop growth simulation and SAR-derived key information, particularly start of season and leaf growth rate. Results from pilot study sites in South and South East Asian countries suggest that incorporation of SAR data into crop model improves yield estimation for actual yields. Remote-sensing data assimilation into crop model effectively capture responses of rice crops to environmental conditions over large spatial coverage, which otherwise is practically impossible to achieve. Such improvement of actual yield estimates offers practical application such as in a crop insurance program. Process-based crop simulation model is used in the system to ensure climate information is adequately captured and to enable mid-season yield forecast.

  2. Quantifying the weather-signal in national crop-yield variability

    NASA Astrophysics Data System (ADS)

    Frieler, K.; Arneth, A.; Balkovic, J.; Chryssanthacopoulos, J.; Deryng, D.; Elliott, J. W.; Folberth, C.; Khabarov, N.; Mueller, C.; Olin, S.; Pugh, T.; Schaphoff, S.; Schewe, J.; Schmid, E.; Schauberger, B.; Warszawski, L.; Levermann, A.

    2015-12-01

    Year-to-year variations in crop yields can have major impacts on the livelihoods of subsistence farmers and may trigger significant global price fluctuations with particularly severe consequences for people in developing countries. The fluctuations can be induced by weather conditions but also by management decisions, diseases, and pests. To get a better understanding of future sensitivities to climate change it is important to quantify the degree to which historical crop yields are determined by weather fluctuations. This separation from other influences is usually done by highly simplified empirical models. In contrast, here we provide a conservative estimate of the fraction of the observed national yield variability that is caused by weather, using state-of-the-art process-based crop model simulations. As these models provide a detailed representation of our current understanding of the underlying processes they are also suitable to assess potential adaptation options. We provide an identification of the countries where the weather induced variability of crop yields is particularly high (explained variance > 50%). In addition, inhibiting water stress by simulating yields assuming full irrigation shows that water limitation is the main driver of the observed variations in most of these countries.

  3. Modeling regional crop yield and irrigation demand using SMAP type of soil moisture data

    NASA Astrophysics Data System (ADS)

    El Sharif, H. A.; Wang, J.; Georgakakos, A. P.; Bras, R. L.

    2013-12-01

    Agricultural models, such as Decision Support System for Agrotechnology Transfer - Cropping Systems Model (DSSAT-CSM) (Tsuji, et al., 1994), have been developed to predict the yield of various crops at field and regional scales. The model simulations of crop yields provide essential information for water resources management. One key input of the agricultural models is soil moisture. So far there are no observed soil moisture data covering the entire US with adequate time (daily) and space (1 km or less) resolutions preferred for model simulation of crop yields. Spatially and temporally downscaled data from the upcoming Soil Moisture Active Passive (SMAP) mission can fill this data gap through the generation of fine resolution soil moisture maps that can be incorporated into DSSAT-CSM model. This study will explore the impact downscaled remotely-sensed soil moisture data can have on agricultural model forecasts of agricultural yield and irrigation demand using synthetically generated data sets exhibiting statistical characteristics (uncertainty) similar to the upcoming SMAP products. It is expected that incorporating this data into agricultural model will prove especially useful for cases in which soil water conductivity characteristics and/or precipitation amount at a specific site of interest are not fully known; furthermore, a proposed Bayesian analysis is expected to generate a soil moisture sequence that reduces the uncertainty in modeled yield and irrigation demand compared to using downscaled remotely-sensed soil moisture or precipitation data alone. References Tsuji, G., Uehara, G., and Balas, S. (1994). DSSAT V3, University of Hawaii, Honolulu.

  4. Impact of historical droughts on crop yields in Sub-Saharan Africa

    NASA Astrophysics Data System (ADS)

    Kamali, Bahareh; Yang, Hong; abbaspour, karim

    2014-05-01

    Sub-Saharan Africa (SSA) has been faced with frequent drought events in the past. Future climate change scenarios have suggested increasing drought frequency and severity. The devastating impacts of drought on rainfed farming and food production pose many challenges in SSA countries both today and in the future. Therefore, a comprehensive investigation of droughts and assessment of their impacts on crop yield and production are critically important to support SSA to formulate effective adaptive measures to improve food security. The current study assesses the historical meteorological and agricultural droughts and quantifies their impacts on two major crop yields namely maize and cassava in SSA. The GIS-based crop model (GEPIC) is used for the simulation of the historical yields. Drought severities are categorized into levels of mild, moderate and severe. The impacts of each category on maize and cassava yields are examined and drought hotspots are highlighted. The knowledge learnt from the historical data helps enhance the projection of the impacts of future weather conditions on crop yield in the region and facilitate the societal preparedness to drought impact.

  5. 7 CFR 1412.34 - Submitting production evidence for establishing direct payment yields for oilseeds and pulse crops.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... direct payment yields for oilseeds and pulse crops. 1412.34 Section 1412.34 Agriculture Regulations of... ELECTION PROGRAM FOR THE 2008 AND SUBSEQUENT CROP YEARS Establishment of Yields for Direct and Counter-Cyclical Payments § 1412.34 Submitting production evidence for establishing direct payment yields...

  6. Temporal changes in climatic variables and their impact on crop yields in southwestern China

    NASA Astrophysics Data System (ADS)

    Liu, Hong-Bin; Gou, Yu; Wang, Hong-Ye; Li, Hong-Mei; Wu, Wei

    2014-08-01

    Knowledge of variability in climatic variables changes and its impact on crop yields is important for farmers and policy makers, especially in southwestern China where rainfed agriculture is dominant. In the current study, six climatic parameters (mean temperature, rainfall, relative humidity, sunshine hours, temperature difference, and rainy days) and aggregated yields of three main crops (rice: Oryza sativa L., oilseed rape: Brassica napus L., and tobacco: Nicotiana tabacum L.) during 1985-2010 were collected and analyzed for Chongqing—a large agricultural municipality of China. Climatic variables changes were detected by Mann-Kendall test. Increased mean temperature and temperature difference and decreased relative humidity were found in annual and oilseed rape growth time series ( P < 0.05). Increased sunshine hours were observed during the oilseed rape growth period ( P < 0.05). Rainy days decreased slightly in annual and oilseed rape growth time series ( P < 0.10). Correlation analysis showed that yields of all three crops could benefit from changes in climatic variables in this region. Yield of rice increased with rainfall ( P < 0.10). Yield of oilseed rape increased with mean temperature and temperature difference but decreased with relative humidity ( P < 0.01). Tobacco yield increased with mean temperature ( P < 0.05). Path analysis provided additional information about the importance and contribution paths of climatic variables to crop yields. Temperature difference and sunshine hours had higher direct and indirect effects via other climatic variables on yields of rice and tobacco. Mean temperature, relative humidity, rainy days, and temperature difference had higher direct and indirect effects via others on yield of oilseed rape.

  7. Ensiling of crops for biogas production: effects on methane yield and total solids determination

    PubMed Central

    2011-01-01

    Background Ensiling is a common method of preserving energy crops for anaerobic digestion, and many scientific studies report that ensiling increases the methane yield. In this study, the ensiling process and the methane yields before and after ensiling were studied for four crop materials. Results The changes in wet weight and total solids (TS) during ensiling were small and the loss of energy negligible. The methane yields related to wet weight and to volatile solids (VS) were not significantly different before and after ensiling when the VS were corrected for loss of volatile compounds during TS and VS determination. However, when the TS were measured according to standard methods and not corrected for losses of volatile compounds, the TS loss during ensiling was overestimated for maize and sugar beet. The same methodological error leads to overestimation of methane yields; when TS and VS were not corrected the methane yield appeared to be 51% higher for ensiled than fresh sugar beet. Conclusions Ensiling did not increase the methane yield of the studied crops. Published methane yields, as well as other information on silage related to uncorrected amounts of TS and VS, should be regarded with caution. PMID:22032645

  8. Bayesian Inference of Baseline Fertility and Treatment Effects via a Crop Yield-Fertility Model

    PubMed Central

    Chen, Hungyen; Yamagishi, Junko; Kishino, Hirohisa

    2014-01-01

    To effectively manage soil fertility, knowledge is needed of how a crop uses nutrients from fertilizer applied to the soil. Soil quality is a combination of biological, chemical and physical properties and is hard to assess directly because of collective and multiple functional effects. In this paper, we focus on the application of these concepts to agriculture. We define the baseline fertility of soil as the level of fertility that a crop can acquire for growth from the soil. With this strict definition, we propose a new crop yield-fertility model that enables quantification of the process of improving baseline fertility and the effects of treatments solely from the time series of crop yields. The model was modified from Michaelis-Menten kinetics and measured the additional effects of the treatments given the baseline fertility. Using more than 30 years of experimental data, we used the Bayesian framework to estimate the improvements in baseline fertility and the effects of fertilizer and farmyard manure (FYM) on maize (Zea mays), barley (Hordeum vulgare), and soybean (Glycine max) yields. Fertilizer contributed the most to the barley yield and FYM contributed the most to the soybean yield among the three crops. The baseline fertility of the subsurface soil was very low for maize and barley prior to fertilization. In contrast, the baseline fertility in this soil approximated half-saturated fertility for the soybean crop. The long-term soil fertility was increased by adding FYM, but the effect of FYM addition was reduced by the addition of fertilizer. Our results provide evidence that long-term soil fertility under continuous farming was maintained, or increased, by the application of natural nutrients compared with the application of synthetic fertilizer. PMID:25405353

  9. Impacts of Different Assimilation Methodologies on Crop Yield Estimates Using Active and Passive Microwave Dataset at L-Band

    NASA Astrophysics Data System (ADS)

    Liu, P.; Bongiovanni, T. E.; Monsivais-Huertero, A.; Bindlish, R.; Judge, J.

    2013-12-01

    estimates. An Ensemble Kalman Filter-based methodology is implemented to incorporate σ0 and TB from Aquarius and SMOS in the DSSAT-A-P model to improve crop yield for two growing seasons of soybean -a normal and a drought affected season- in the rain-fed region of the Brazilian La Plata Basin, South America. Different scenarios of assimilation, including active only, passive only, and combined AP observations were considered. The elements of the state vector included both model states and parameters related to soil and vegetation. The number of elements included in the state vector changed depending upon different scenarios of assimilation and also upon the growth stages. Crop yield estimates were compared for different scenarios during the two seasons. A synthetic experiment conducted previously showed an improvement of crop estimates in the RMSD by 90 kg/ha using combined AP compared to the openloop and active only assimilation over the region.

  10. Integrating remote sensing, geographic information system and modeling for estimating crop yield

    NASA Astrophysics Data System (ADS)

    Salazar, Luis Alonso

    This thesis explores various aspects of the use of remote sensing, geographic information system and digital signal processing technologies for broad-scale estimation of crop yield in Kansas. Recent dry and drought years in the Great Plains have emphasized the need for new sources of timely, objective and quantitative information on crop conditions. Crop growth monitoring and yield estimation can provide important information for government agencies, commodity traders and producers in planning harvest, storage, transportation and marketing activities. The sooner this information is available the lower the economic risk translating into greater efficiency and increased return on investments. Weather data is normally used when crop yield is forecasted. Such information, to provide adequate detail for effective predictions, is typically feasible only on small research sites due to expensive and time-consuming collections. In order for crop assessment systems to be economical, more efficient methods for data collection and analysis are necessary. The purpose of this research is to use satellite data which provides 50 times more spatial information about the environment than the weather station network in a short amount of time at a relatively low cost. Specifically, we are going to use Advanced Very High Resolution Radiometer (AVHRR) based vegetation health (VH) indices as proxies for characterization of weather conditions.

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

    PubMed Central

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

    2000-01-01

    Wheat, cotton, and peanut were arranged in three cropping sequences to determine the effects of fenamiphos (6.7 kg a.i./ha) and cropping sequence on nematode population densities and crop yields under conservation tillage and irrigation for 6 years. The cropping sequences included a wheat winter cover crop each year and summer crops of cotton every year, peanut every year, or cotton rotated every other year with peanut. The population densities of Meloidogyne spp. and Helicotylenchus dihystera were determined monthly during the experiment. Numbers of M. incognita increased on cotton and decreased on peanut, whereas M. arenaria increased on peanut, and decreased on cotton; both nematode species remained in moderate to high numbers in plots of wheat. Root damage was more severe on cotton than peanut and was not affected by fenamiphos treatment. The H. dihystera population densities were highest in plots with cotton every summer, intermediate in the cotton-peanut rotation, and lowest in plots with peanut every summer. Over all years and cropping sequences, yield increases in fenamiphos treatment over untreated control were 9% for wheat, 8% for cotton, and 0% for peanut. Peanut yields following cotton were generally higher than yields following peanut. These results show that nematode problems may be manageable in cotton and peanut production under conservation tillage and irrigation in the southeastern United States. PMID:19270949

  12. Effects of No-Till on Yields as Influenced by Crop and Environmental Factors

    SciTech Connect

    Toliver, Dustin K.; Larson, James A.; Roberts, Roland K.; English, B.C.; De La Torre Ugarte, D. G.; West, Tristram O.

    2012-02-07

    Th is research evaluated diff erences in yields and associated downside risk from using no-till and tillage practices. Yields from 442 paired tillage experiments across the United States were evaluated with respect to six crops and environmental factors including geographic location, annual precipitation, soil texture, and time since conversion from tillage to no-till. Results indicated that mean yields for sorghum [Sorghum bicolor (L.) Moench] and wheat (Triticum aestivum L.) with no-till were greater than with tillage. In addition, no-till tended to produce similar or greater mean yields than tillage for crops grown on loamy soils in the Southern Seaboard and Mississippi Portal regions. A warmer and more humid climate and warmer soils in these regions relative to the Heartland, Basin and Range, and Fruitful Rim regions appear to favor no-till on loamy soils. With the exception of corn (Zea mays L.) and cotton (Gossypium hirsutum L.) in the Southern Seaboard region, no-till performed poorly on sandy soils. Crops grown in the Southern Seaboard were less likely to have lower no-till yields than tillage yields on loamy soils and thus had lower downside yield risk than other farm resource regions. Consistent with mean yield results, soybean [Glycine max (L.) Merr.] and wheat grown on sandy soils in the Southern Seaboard region using no-till had larger downside yield risks than when produced with no-till on loamy soils. Th e key fi ndings of this study support the hypothesis that soil and climate factors impact no-till yields relative to tillage yields and may be an important factor infl uencing risk and expected return and the adoption of the practice by farmers.

  13. Climatological sensitivity analysis of crop yield to changes in temperature and precipitation using particle filter

    NASA Astrophysics Data System (ADS)

    Yokozawa, M.; Sakurai, G.; Iizumi, T.

    2010-12-01

    The climatological sensitivities of crop yields to changes in mean temperature and precipitation during a period of the growing season were statistically examined. The sensitivity is defined as the change of yield in response to the change of climatic condition in the growth period from sowing to harvesting. The objective crops are maize and soybean, which are being cultivated in United States, Brazil and China as the world major production countries. We collected the yield data of maize and soybean on county level of United States from USDA during a period of 1980-2006, on Município level of Brazil during a period of 1990-2006 and on Xiàn level of China during a period of 1980-2005. While the data on only four provinces in China are used (Heilongjiang, Henan, Liaoning, and Shandong), total production of the four provinces reaches about 40% (maize) and 51% (soybean) to the country total (USDA 1997). We used JRA-25 reanalysis climate data distributed from the Japanese Meteorological Agency during a period of 1980 through 2006 with a resolution of 1.125° in latitude and longitude. To coincide in resolution, the crop yield data were reallocated into the same grids as climate. To eliminate economical and technical effects on yield, we detrended the time series data of yield and climate. We applied a local regression model to conduct the detrend (cubic weighting and M estimator of Tukey's bi-weight function). The time series data on the deviation from the trend were examined with the changes in temperature and precipitation for each grid using the particle filter. The particle filter used here is based on self-organizing state-space model. As a result, in the northern hemisphere, positive sensitivity, i.e. increase in temperature shifts the crop yield positively, is generally found especially in higher latitude, while negative sensitivity is found in the lower latitude. The neutral sensitivity is found in the regions where the mean temperature during growing season

  14. Characterization of yield reduction in Ethiopia using a GIS-based crop water balance model

    USGS Publications Warehouse

    Senay, G.B.; Verdin, J.

    2003-01-01

    In many parts of sub-Saharan Africa, subsistence agriculture is characterized by significant fluctuations in yield and production due to variations in moisture availability to staple crops. Widespread drought can lead to crop failures, with associated deterioration in food security. Ground data collection networks are sparse, so methods using geospatial rainfall estimates derived from satellite and gauge observations, where available, have been developed to calculate seasonal crop water balances. Using conventional crop production data for 4 years in Ethiopia (1996-1999), it was found that water-limited and water-unlimited growing regions can be distinguished. Furthermore, maize growing conditions are also indicative of conditions for sorghum. However, another major staple, teff, was found to behave sufficiently differently from maize to warrant studies of its own.

  15. Estimation of winter wheat yield by using remote sensing data and crop model

    NASA Astrophysics Data System (ADS)

    Guo, Jianmao; Zheng, Tengfei; Wang, Qi; Yang, Jia; Shi, Junyi; Zhu, Jinhui

    2012-10-01

    Remote sensing data combined with crop model is an important application and development trend of current agricultural information technology, it can solve the problem that remote sensing or crop model cannot solve alone. In order to simulate crop growth and yield prediction in large scale, this paper using field test data to calibrate and validation the model parameters before apply to the winter wheat WOFOST model, than according to the actual environment of Xinxiang, simulate the growth in 3 different condition in the 2002-2003 growing season. Contrast the simulation value WOFOST model, using the Landsat-7 ETM retrieving leaf area index, define winter wheat's growth condition in each pixel, the remote sensing information combined with crop model is accomplished at pixel scale. Based on the actual production of Xinxiang winter wheat in 2003,compare the simulate results with the corresponding parameter, results shows that the method of this study method is feasible.

  16. Hormonal and metabolic regulation of source-sink relations under salinity and drought: from plant survival to crop yield stability.

    PubMed

    Albacete, Alfonso A; Martínez-Andújar, Cristina; Pérez-Alfocea, Francisco

    2014-01-01

    Securing food production for the growing population will require closing the gap between potential crop productivity under optimal conditions and the yield captured by farmers under a changing environment, which is termed agronomical stability. Drought and salinity are major environmental factors contributing to the yield gap ultimately by inducing premature senescence in the photosynthetic source tissues of the plant and by reducing the number and growth of the harvestable sink organs by affecting the transport and use of assimilates between and within them. However, the changes in source-sink relations induced by stress also include adaptive changes in the reallocation of photoassimilates that influence crop productivity, ranging from plant survival to yield stability. While the massive utilization of -omic technologies in model plants is discovering hundreds of genes with potential impacts in alleviating short-term applied drought and salinity stress (usually measured as plant survival), only in relatively few cases has an effect on crop yield stability been proven. However, achieving the former does not necessarily imply the latter. Plant survival only requires water status conservation and delayed leaf senescence (thus maintaining source activity) that is usually accompanied by growth inhibition. However, yield stability will additionally require the maintenance or increase in sink activity in the reproductive structures, thus contributing to the transport of assimilates from the source leaves and to delayed stress-induced leaf senescence. This review emphasizes the role of several metabolic and hormonal factors influencing not only the source strength, but especially the sink activity and their inter-relations, and their potential to improve yield stability under drought and salinity stresses. PMID:24513173

  17. Assessment of Impacts of Climate Variability on Crop Yield over the Terai Region of Nepal

    NASA Astrophysics Data System (ADS)

    Subedi, S.; Acharya, A.

    2015-12-01

    Agricultural sector in Nepal which alone contributes about 42 % of the total GDP have a huge influence on national economy. This sector is very much susceptible to climate change. This study is emphasized on Terai region (situated at an altitude of 60m to 300m) of Nepal which investigates the impacts of climate variability on various stages of cropping (paddy) periods such as transplant, maturity and harvest. The climate variables namely temperature and rainfall are used to explore the relationship between climate and paddy yields based on 30 years of historical observed data. Observed monthly rainfall and temperature data are collected from the department of hydrology and meteorology, and paddy yield data are collected from the Ministry of Agricultural Development. A correlation analysis will be carried out between the backward difference filtered climate parameters and the backward difference filtered rice yield. This study will also analyze average monthly and annual rainfall, and, min, max and mean temperature during the period of 1981-2010 based on 15 synoptic stations of Nepal. This study will visualize rainfall and temperature distribution over Nepal, and also evaluate the effect of change in rainfall and temperature in the paddy yield. While evaluating the impacts of climate on crop yield, this study will not consider the impact of irrigation in crop yield. The major results, climate distribution and its local/regional impacts on agriculture, could be utilized by planners, decision makers, and climate and agricultural scientists as a basis in formulating/implementing future plans, policies and projects.

  18. Impact of different cover crops and types of transplanter mounted subsoiler shanks on tomato yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A four year experiment with different tillage practices for tomatoes was conducted in Cullman, AL to determine the impact of plastic mulch (control), rye and crimson clover cover crops, and different subsoiler shanks (no shank, slim 13 mm thick, and wide 20 mm thick) on tomato yield. Overall, in 200...

  19. EPIC Simulations of Crop Yields and Soil Organic Carbon in Iowa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Depending on management, soil organic carbon is source or sink of atmospheric carbon dioxide. The Environmental Policy Integrated Climate (EPIC) model is a useful tool for predicting impacts of soil management on crop yields and soil organic carbon. We used EPIC-Century to simulate changes in soil o...

  20. Global Food Insecurity? Lower Than Expected Crop Yield Stimulation with Rising Carbon Dioxide Concentrations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Predictions of yield for the globe's major grain and legume arable crops suggest that, with a moderate temperature increase, production may increase in the temperate zone, but decline in the tropics. In total, global food supply may show little change. This security comes from inclusion of the dir...

  1. Changes in Soil Moisture with Cover Crops and Tillage: Impact on Cotton Yield and Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The alluvial soils of the lower Mississippi River flood plain are highly productive, but low in organic matter. Use of irrigation in the area has increased in order to ensure adequate yield return. Use of cover crops has been used in other areas to increase soil organic matter and improve infiltrati...

  2. Crop yield estimation based on unsupervised linear unmixing of multidate hyperspectral imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyperspectral imagery, which contains hundreds of spectral bands, has the potential to better describe the biological and chemical attributes on the plants than multispectral imagery and has been evaluated in this paper for the purpose of crop yield estimation. The spectrum of each pixel in a hypers...

  3. Predicting the impact of changing CO2 on crop yields: Some thoughts on food

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent breakthroughs in CO2 fumigation methods using free-air CO2 enrichment (FACE) technology have prompted comparisons between FACE experiments and "enclosure studies" with respect to quantification of projected atmospheric CO2 concentrations on crop yields. Based on one such comparison, it was a...

  4. Applying linear spectral unmixing to airborne hyperspectral imagery for mapping crop yield variability.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated linear spectral unmixing techniques for mapping the variation in crop yield. Both unconstrained and constrained linear spectral unmixing models were applied to airborne hyperspectral imagery recorded from one grain sorghum field and a cotton field. A pair of plant and soil spect...

  5. Three years of crop yields using drainage water management at eight sites in Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drainage water management (NRCS-Practice Code 554) is an important water management practice for dealing with nitrate-loading across the Midwest US. A multi-year study is being conducted in Ohio to evaluate the effects of drainage water management on crop yield and water quality. We have installed w...

  6. TILLAGE, COVER CROPS, AND NITROGEN FERTILIZATION EFFECTS ON SOIL NITROGEN AND COTTON AND SORGHUM YIELDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustainable soil and crop management practices that reduce soil erosion and nitrogen (N) leaching, conserve soil organic matter, and optimize cotton and sorghum yields still remain a challenge. We examined the influence of three tillage practices (no-till, strip till, and chisel till ), four cover c...

  7. Potential for Improved Crop Yield Prediction Through Assimilation of Satellite-Derived Soil Moisture Data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop yield estimates have a strong impact on dealing with food shortages and on market demand and supply; these estimates are critical for decision-making processes by the U.S. Government, policy makers, stakeholders, etc. Most of the decision making is based on forecasts provided by the U.S. Depart...

  8. Understanding the relative influence of climatic variations and agricultural management practices on crop yields at the US county level

    NASA Astrophysics Data System (ADS)

    Leng, G.; Zhang, X.; Huang, M.; Yang, Q.; Rafique, R.; Asrar, G.; Leung, L. R.

    2015-12-01

    Crop yields are largely determined by climate variations and agricultural management practices, such as irrigation, fertilization and residue management. Understanding the role of these factors in regulating crop yield variations is not only important for improved crop yield production, but also equally valuable for future crop yield prediction and food security assessments. Recently, the Community Land Model (CLM) has been augmented and evaluated for simulating corn, soybean and cereals at coarse aerial resolutions of 2 degrees (2000x2000 km). To better understand the underlying mechanisms controlling yield variations, we implemented and validated the agricultural version of CLM (CLM-crop) at a 0.125 degree resolution over the Conterminous United States (CONUS). We conducted a suite of numerical experiments to untangle the relative influence of climatic variations (temperature, precipitation, and radiation) and agricultural management practices on yield variations for the past 30 years at the US county level. Preliminary results show that the model with default parameter settings captures well the temporal variations in crop yields, as compared with the actual yield reported by the US Department of Agriculture (USDA). However, the magnitude of simulated crop yields is substantially higher, especially in the Mid-western US. We find that improved characterization of fertilizers and irrigation practices is key to model performance. Retrospectively (1979-2012), crop yields are more sensitive to changes in climate factors (such as temperature) than to changes in crop management practices. The results of this study advances understanding of the dominant factors in regulating the crop yield variations at the county level, which is essential for credible prediction of crop yields in a changing climate, under different agricultural management practices.

  9. Impact of climate change on crop yield and role of model for achieving food security.

    PubMed

    Kumar, Manoj

    2016-08-01

    In recent times, several studies around the globe indicate that climatic changes are likely to impact the food production and poses serious challenge to food security. In the face of climate change, agricultural systems need to adapt measures for not only increasing food supply catering to the growing population worldwide with changing dietary patterns but also to negate the negative environmental impacts on the earth. Crop simulation models are the primary tools available to assess the potential consequences of climate change on crop production and informative adaptive strategies in agriculture risk management. In consideration with the important issue, this is an attempt to provide a review on the relationship between climate change impacts and crop production. It also emphasizes the role of crop simulation models in achieving food security. Significant progress has been made in understanding the potential consequences of environment-related temperature and precipitation effect on agricultural production during the last half century. Increased CO2 fertilization has enhanced the potential impacts of climate change, but its feasibility is still in doubt and debates among researchers. To assess the potential consequences of climate change on agriculture, different crop simulation models have been developed, to provide informative strategies to avoid risks and understand the physical and biological processes. Furthermore, they can help in crop improvement programmes by identifying appropriate future crop management practises and recognizing the traits having the greatest impact on yield. Nonetheless, climate change assessment through model is subjected to a range of uncertainties. The prediction uncertainty can be reduced by using multimodel, incorporating crop modelling with plant physiology, biochemistry and gene-based modelling. For devloping new model, there is a need to generate and compile high-quality field data for model testing. Therefore, assessment of

  10. Estimating maize grain yield from crop biophysical parameters using remote sensing

    NASA Astrophysics Data System (ADS)

    Guindin-Garcia, Noemi

    The overall objective of this investigation was to develop a robust technique to predict maize (Zea mays L.) grain yield that could be applied at a regional level using remote sensing with or without a simple crop growth simulation model. This study evaluated capabilities and limitations of the Moderate Resolution Imaging Spectroradiometer (MODIS) Vegetation Index 250-m and MODIS surface reflectance 500-m products to track and retrieve information over maize fields. Results demonstrated the feasibility of using MODIS data to estimate maize green leaf area index (LAIg). Estimates of maize LAIg obtained from Wide Dynamic Range Vegetation Index using data retrieved from MODIS 250-m products (e.g. MOD13Q1) can be incorporated in crop simulation models to improve LAIg simulations by the Muchow-Sinclair-Bennet (MSB) model reducing the RMSE of LAIg simulations for all years of study under irrigation. However, more accurate estimates of LAIg did not necessarily imply better final yield (FY) predictions in the MSB maize model. The approach of incorporating better LAIg estimates into crop simulation models may not offer a panacea for problem solving; this approach is limited in its ability to simulate other factors influencing crop yields. On the other hand, the approach of relating key crop biophysical parameters at the optimum stage with maize grain final yields is a robust technique to early FY estimation over large areas. Results suggest that estimates of LAI g obtained during the mid-grain filling period can used to detect variability of maize grain yield and this technique offers a rapid and accurate (RMSE < 900 kg ha-1) method to detect FY at county level using MODIS 250-m products.

  11. From the ground up: The role of climate versus management on global crop yield patterns

    NASA Astrophysics Data System (ADS)

    Licker, R.; Johnston, M.; Foley, J. A.; Ramankutty, N.

    2008-12-01

    Agricultural lands are one of the most expansive land cover types on Earth, extending across approximately 12 percent of the planet's land surface. The management of these lands has changed dramatically since the Green Revolution of the 1960s. Nitrogen fertilizer inputs are almost 7 times greater, and irrigated lands have nearly doubled. Yet, the number of undernourished people is still increasing, and may continue to as the world's population is expected to grow by 2.5 billion people over the next three decades. In addition, there is a shift toward diets heavy in grain-fed meats taking place, as well as an increase in the demand of grains for fuel. While an altered distribution of crops may help remedy some of our food shortages, humanity will need to produce more if it is to meet its demands for crops. Obtaining more crops could entail both an expansion of agricultural lands as well as a change in the way many lands are currently managed - scenarios that would have implications for ecosystem goods and services at large given agriculture's already prominent place on the planet's landscape. Here, we explore society's ability to increase yields on existing croplands by way of altered management. We begin by quantifying the current influence that management practices such as chemical fertilizer use and irrigation have on global crop yield patterns relative to biophysical factors such as climate. In particular, we test the traditional assumption that more intensively managed lands have higher yields. We utilize new global, gridded maps of cropland cover and yields, as well as new maps showing climatically determined crop yield potentials. With this, we hope to contribute to a discussion of how we might, as a civilization, continue to shape our planet's land cover in pursuit of food, feed, and fuel.

  12. Colored plastic mulch microclimates affect strawberry fruit yield and quality.

    PubMed

    Shiukhy, Saeid; Raeini-Sarjaz, Mahmoud; Chalavi, Vida

    2015-08-01

    Significant reduction of strawberry (Fragaria × ananassa, Duch.) fruit yield and quality, as a consequence of conventional cultivation method, is common in the Caspian Sea region, Iran. Recently, growers started using plastic mulches to overcome these shortcomings. Plastic mulches have different thermal and radiation properties and could affect strawberry fruit yield and quality. In the present study, the effect of different colored plastic mulches (black, red, and white) along with conventional practice was tested on yield and quality of strawberry Camarosa cultivar, in a completely randomized block design. Colored plastic mulches had highly significant effect on fruit weight, size, and phytochemical contents. In the most harvest times, mean fruit weight was significantly higher in red plastic relative to white and control treatments. Total fruit weight of plastic mulches was not significantly different, while all were statistically higher than that of control. Fruit size significantly increased over red plastic mulch. Total fruit numbers over plastic mulches were significantly higher than that of control treatment. The content of phenolic compounds was similar between treatments, while anthocyanin content, IC(50) value, and flavonoid content significantly were affected by colored plastics. In conclusion, colored plastic mulches could affect strawberry fruit weight and quality through altering strawberry thermal and radiation environment. PMID:25348886

  13. Colored plastic mulch microclimates affect strawberry fruit yield and quality

    NASA Astrophysics Data System (ADS)

    Shiukhy, Saeid; Raeini-Sarjaz, Mahmoud; Chalavi, Vida

    2015-08-01

    Significant reduction of strawberry ( Fragaria × ananassa, Duch.) fruit yield and quality, as a consequence of conventional cultivation method, is common in the Caspian Sea region, Iran. Recently, growers started using plastic mulches to overcome these shortcomings. Plastic mulches have different thermal and radiation properties and could affect strawberry fruit yield and quality. In the present study, the effect of different colored plastic mulches (black, red, and white) along with conventional practice was tested on yield and quality of strawberry Camarosa cultivar, in a completely randomized block design. Colored plastic mulches had highly significant effect on fruit weight, size, and phytochemical contents. In the most harvest times, mean fruit weight was significantly higher in red plastic relative to white and control treatments. Total fruit weight of plastic mulches was not significantly different, while all were statistically higher than that of control. Fruit size significantly increased over red plastic mulch. Total fruit numbers over plastic mulches were significantly higher than that of control treatment. The content of phenolic compounds was similar between treatments, while anthocyanin content, IC50 value, and flavonoid content significantly were affected by colored plastics. In conclusion, colored plastic mulches could affect strawberry fruit weight and quality through altering strawberry thermal and radiation environment.

  14. Heterosis, stress, and the environment: a possible road map towards the general improvement of crop yield.

    PubMed

    Blum, Abraham

    2013-11-01

    Contemporary plant breeding is under pressure to improve crop productivity at a rate surpassing past achievements. Different research groups dealing with this issue reached similar conclusions that the solution lies in improved biomass production by way of enhanced light capture and use efficiency, modified photosystem biochemistry, and improved partitioning of assimilates to the economic part of the plant. There seems to be a consensus of sorts. This 'opinion paper' calls attention to the phenomenon of heterosis, as expressed in maize, sorghum, and other crops where, depending on the case and the trait, larger biomass and greater yield have been achieved without a change in growth duration, photosystem biochemistry, or harvest index. This discussion maintains that there is no consensus about the genetics or the genomics of heterosis in regulating yield under diverse environments. Therefore, in a search for the basis of heterosis in yield and adaptation, the discussion bypasses the genetics and searches for answers in the phenomics of heterosis. The heterotic phenotype in itself provides challenging and important hints towards improving the yield of open-pollinated crops in general. These hints are linked to the homeostasis of photosynthesis with respect to temperature, the photobiology of the plant as mediated by phytochrome, the architectural foundations of the formation of a large sink, and the associated hormones and signals in controlling sink differentiation and source-sink communication. This discussion does not lay out plans and protocols but provides clues to explore within and beyond the current thinking about breeding for high yield. PMID:24014873

  15. Evaluation of crop yield simulations in the SE USA using the NARCCAP regional climate models

    NASA Astrophysics Data System (ADS)

    Cocke, S.; Shin, D. W.; Baigorria, G. A.; Romero, C. C.

    2015-12-01

    We integrate climate projections, crop modeling systems and economic assessment to develop a tool for studying and assessing agricultural production in the southeast United States. This integrated framework will enable us to assess the potential impact of future climate variability and trend on the production of economically-valuable crops in the southeast United States where weather/climate has major effects on agricultural yields. Optimally weighted multi-model ensemble (MME) approaches are used in order to improve the projection of future regional crop yield. This research will enhance the current knowledge of linking climate and process models, with an economic evaluation, as a demonstration of an approach that can be applied for other settings, problems, etc. The current maize/peanut/cotton yields and the future yield projections over the southeast US were obtained using (a) observed COOP data (1971-2010), (b) a reanalysis (NCEP R2), and (c) the NARCCAP (CMIP3) ensemble data for irrigated and non-irrigated conditions with 7 to 8 different planting dates (potential adaptation options). We found that the future yield amounts over the southeast US are generally decreased in the NARCCAP runs.

  16. Aerobic Decomposition and Organic Amendments Effects on Grain Yield of Triple-Cropped Rice in the Mekong Delta, Vietnam

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil aeration during decomposition of incorporated crop residues and application of organic amendments might help improve soil quality and rice yield for sustainable intensive rice production. A field experiment was conducted on triple-cropped rice during three consecutive crops with five treatments...

  17. Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations

    NASA Astrophysics Data System (ADS)

    Long, Stephen P.; Ainsworth, Elizabeth A.; Leakey, Andrew D. B.; Nösberger, Josef; Ort, Donald R.

    2006-06-01

    Model projections suggest that although increased temperature and decreased soil moisture will act to reduce global crop yields by 2050, the direct fertilization effect of rising carbon dioxide concentration ([CO2]) will offset these losses. The CO2 fertilization factors used in models to project future yields were derived from enclosure studies conducted approximately 20 years ago. Free-air concentration enrichment (FACE) technology has now facilitated large-scale trials of the major grain crops at elevated [CO2] under fully open-air field conditions. In those trials, elevated [CO2] enhanced yield by ~50% less than in enclosure studies. This casts serious doubt on projections that rising [CO2] will fully offset losses due to climate change.

  18. Soil Moisture Anomaly as Predictor of Crop Yield Deviation in Germany

    NASA Astrophysics Data System (ADS)

    Peichl, Michael; Thober, Stephan; Schwarze, Reimund; Meyer, Volker; Samaniego, Luis

    2016-04-01

    Natural hazards, such as droughts, have the potential to drastically diminish crop yield in rain-fed agriculture. For example, the drought in 2003 caused direct losses of 1.5 billion EUR only in Germany (COPA-COGECA 2003). Predicting crop yields allows to economize the mitigation of risks of weather extremes. Economic approaches for quantifying agricultural impacts of natural hazards mainly rely on temperature and related concepts. For instance extreme heat over the growing season is considered as best predictor of corn yield (Auffhammer and Schlenker 2014). However, those measures are only able to provide a proxy for the available water content in the root zone that ultimately determines plant growth and eventually crop yield. The aim of this paper is to analyse whether soil moisture has a causal effect on crop yield that can be exploited in improving adaptation measures. For this purpose, reduced form fixed effect panel models are developed with yield as dependent variable for both winter wheat and silo maize crops. The explanatory variables used are soil moisture anomalies, precipitation and temperature. The latter two are included to estimate the current state of the water balance. On the contrary, soil moisture provides an integrated signal over several months. It is also the primary source of water supply for plant growth. For each crop a single model is estimated for every month within the growing period to study the variation of the effects over time. Yield data is available for Germany as a whole on the level of administrative districts from 1990 to 2010. Station data by the German Weather Service are obtained for precipitation and temperature and are aggregated to the same spatial units. Simulated soil moisture computed by the mesoscale Hydrologic Model (mHM, www.ufz.de/mhm) is transformed into Soil Moisture Index (SMI), which represents the monthly soil water quantile and hence accounts directly for the water content available to plants. The results

  19. Multiyear high-resolution carbon exchange over European croplands from the integration of observed crop yields into CarbonTracker Europe

    NASA Astrophysics Data System (ADS)

    Combe, Marie; Vilà-Guerau de Arellano, Jordi; de Wit, Allard; Peters, Wouter

    2016-04-01

    Carbon exchange over croplands plays an important role in the European carbon cycle over daily-to-seasonal time scales. Not only do crops occupy one fourth of the European land area, but their photosynthesis and respiration are large and affect CO2 mole fractions at nearly every atmospheric CO2 monitoring site. A better description of this crop carbon exchange in our CarbonTracker Europe data assimilation system - which currently treats crops as unmanaged grasslands - could strongly improve its ability to constrain terrestrial carbon fluxes. Available long-term observations of crop yield, harvest, and cultivated area allow such improvements, when combined with the new crop-modeling framework we present. This framework can model the carbon fluxes of 10 major European crops at high spatial and temporal resolution, on a 12x12 km grid and 3-hourly time-step. The development of this framework is threefold: firstly, we optimize crop growth using the process-based WOrld FOod STudies (WOFOST) agricultural crop growth model. Simulated yields are downscaled to match regional crop yield observations from the Statistical Office of the European Union (EUROSTAT) by estimating a yearly regional parameter for each crop species: the yield gap factor. This step allows us to better represent crop phenology, to reproduce the observed multiannual European crop yields, and to construct realistic time series of the crop carbon fluxes (gross primary production, GPP, and autotrophic respiration, Raut) on a fine spatial and temporal resolution. Secondly, we combine these GPP and Raut fluxes with a simple soil respiration model to obtain the total ecosystem respiration (TER) and net ecosystem exchange (NEE). And thirdly, we represent the horizontal transport of carbon that follows crop harvest and its back-respiration into the atmosphere during harvest consumption. We distribute this carbon using observations of the density of human and ruminant populations from EUROSTAT. We assess the model

  20. Effects of Cropping Sequences on Population Densities of Meloidogyne hapla and Carrot Yield in Organic Soil.

    PubMed

    Bélair, G

    1992-09-01

    The influence of various cropping sequences on population densities of Meloidogyne hapla and carrot yield was studied in organic soil under microplot-and field conditions. Spinach, radish, barley, oat, and wheat were poor or nonhosts for M. hapla. Population densities of M. hapla were maintained or increased on cabbage, celery, lettuce, leek, marigold, and potato. Marketable percent-age and root weight of carrots were greater following spinach, oat, radish, and fallow-onion than those following two crops of onion or carrot in microplots. Under field conditions, the carrot-onion-oat-carrot cropping sequence decreased M. hapla population densities and provided a 282% increase in marketable yield of carrot compared to a carrot monoculture. Two consecutive years of onion increased M. hapla population densities causing severe root galling and a 50% yield loss in the following crop of carrot. Based on root-gall indices, carrots could be grown economically for 2 years following radish, spinach, and oat, but not following onion and carrot without the use of nematicides. PMID:19283022

  1. Airborne monitoring of crop canopy temperatures for irrigation scheduling and yield prediction

    NASA Technical Reports Server (NTRS)

    Millard, J. P.; Jackson, R. D.; Goettelman, R. C.; Reginato, R. J.; Idso, S. B.; Lapado, R. L.

    1977-01-01

    Airborne and ground measurements were made on April 1 and 29, 1976, over a USDA test site consisting mostly of wheat in various stages of water stress, but also including alfalfa and bare soil. These measurements were made to evaluate the feasibility of measuring crop temperatures from aircraft so that a parameter termed stress degree day, SDD, could be computed. Ground studies have shown that SDD is a valuable indicator of a crop's water needs, and that it can be related to irrigation scheduling and yield. The aircraft measurement program required predawn and afternoon flights coincident with minimum and maximum crop temperatures. Airborne measurements were made with an infrared line scanner and with color IR photography. The scanner data were registered, subtracted, and color-coded to yield pseudo-colored temperature-difference images. Pseudo-colored images reading directly in daily SDD increments were also produced. These maps enable a user to assess plant water status and thus determine irrigation needs and crop yield potentials.

  2. Statistical rice yield modeling using blended MODIS-Landsat based crop phenology metrics in Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, C. R.; Chen, C. F.; Nguyen, S. T.; Lau, K. V.

    2015-12-01

    Taiwan is a populated island with a majority of residents settled in the western plains where soils are suitable for rice cultivation. Rice is not only the most important commodity, but also plays a critical role for agricultural and food marketing. Information of rice production is thus important for policymakers to devise timely plans for ensuring sustainably socioeconomic development. Because rice fields in Taiwan are generally small and yet crop monitoring requires information of crop phenology associating with the spatiotemporal resolution of satellite data, this study used Landsat-MODIS fusion data for rice yield modeling in Taiwan. We processed the data for the first crop (Feb-Mar to Jun-Jul) and the second (Aug-Sep to Nov-Dec) in 2014 through five main steps: (1) data pre-processing to account for geometric and radiometric errors of Landsat data, (2) Landsat-MODIS data fusion using using the spatial-temporal adaptive reflectance fusion model, (3) construction of the smooth time-series enhanced vegetation index 2 (EVI2), (4) rice yield modeling using EVI2-based crop phenology metrics, and (5) error verification. The fusion results by a comparison bewteen EVI2 derived from the fusion image and that from the reference Landsat image indicated close agreement between the two datasets (R2 > 0.8). We analysed smooth EVI2 curves to extract phenology metrics or phenological variables for establishment of rice yield models. The results indicated that the established yield models significantly explained more than 70% variability in the data (p-value < 0.001). The comparison results between the estimated yields and the government's yield statistics for the first and second crops indicated a close significant relationship between the two datasets (R2 > 0.8), in both cases. The root mean square error (RMSE) and mean absolute error (MAE) used to measure the model accuracy revealed the consistency between the estimated yields and the government's yield statistics. This

  3. Comparing the simulation of climate impacts on crop yields with observed and synthetic weather data

    NASA Astrophysics Data System (ADS)

    Qian, B.; de Jong, R.; Yang, J.; Wang, H.; Gameda, S.

    2010-12-01

    Stochastic weather generators have been used extensively in the development of climate scenarios, especially at the daily or shorter time scales, for the use as climate input to agricultural simulation models that evaluate the climate impacts on crop yields. Because generated synthetic weather data mimic the observed weather data, discrepancies between the two datasets often exist. For example, interannual variability in the synthetic data is often found to be weaker than in the observed data, i.e., the well-known overdispersion problem. Therefore, it is important to evaluate if the climate impact models are sensitive to such discrepancies between synthetic weather data and observed ones. In this study, we used a stochastic weather generator (AAFC-WG) to generate 300-yr long synthetic weather data for two Canadian sites (Swift Current on the Canadian Prairies and London in southern Ontario), based on the observed weather data for the baseline period of 1961-1990. The Decision Support System for Agrotechnology Transfer (DSSAT) v4.0 was employed to simulate crop growth and yield. Spring wheat at Swift Current and grain corn at London were simulated by the DSSAT cropping system model with three major soil types at each location, using the 30-yr observed weather data and 300-yr synthetic data, respectively. Statistical tests were performed to investigate whether differences (both mean and variance) of the simulated crop yields between the simulations with observed and synthetic weather data are statistically significant or not. Results demonstrated that the differences in simulated crop yields are often not statistically significant when synthetic weather data are used to substitute the observed data.

  4. Assessment of reclaimed water irrigation on growth, yield, and water-use efficiency of forage crops

    NASA Astrophysics Data System (ADS)

    Alkhamisi, S. A.; Abdelrahman, H. A.; Ahmed, M.; Goosen, M. F. A.

    2011-09-01

    Field experiments were conducted to determine the effect of water quality (reclaimed and fresh water), water quantity, and their interactions on the growth, yield, and water use efficiency of forage maize during two winter seasons in the Arabian Gulf. The plants irrigated with the reclaimed water had higher plant height than those irrigated with the fresh water. The leaf length and leaf area (cm2) did not show any significant differences among the interaction. Reclaimed water had shorter time for 50% male and female flowering of forage maize plants, indicating earlier maturity. Plants irrigated with reclaimed water had higher chlorophyll content for all levels of water applications. A significant difference in green forage yield was found among the interactions. Reclaimed water gave the highest green forage yield of 72.12 and 59.40 t/ha at 1.4ETo and 1.0ETo, respectively. Plants irrigated with the reclaimed water used water more efficiently [3.65 kg/m3 of DM (dry matter)] than those irrigated with the fresh water [2.91 kg/m3 of DM (dry matter)] for all water quantities. The enhanced growth in wastewater-irrigated crops, compared with fresh water-irrigated crops, was attributed primarily to higher nutrient content (e.g., nitrogen) and lower salinity of the reclaimed water. The study concluded that treated wastewater irrigation increased yields of forage crops and their water use efficiency. Cost-benefit analysis, studies on the use these forage crops as animal feed, and more in depth evaluation of possible crop and soil contamination were recommended.

  5. A comprehensive assessment of the correlations between field crop yields and commonly used MODIS products

    NASA Astrophysics Data System (ADS)

    Johnson, David M.

    2016-10-01

    An exploratory assessment was undertaken to determine the correlation strength and optimal timing of several commonly used Moderate Resolution Imaging Spectroradiometer (MODIS) composited imagery products against crop yields for 10 globally significant agricultural commodities. The crops analyzed included barley, canola, corn, cotton, potatoes, rice, sorghum, soybeans, sugarbeets, and wheat. The MODIS data investigated included the Normalized Difference Vegetation Index (NDVI), Fraction of Photosynthetically Active Radiation (FPAR), Leaf Area Index (LAI), and Gross Primary Production (GPP), in addition to daytime Land Surface Temperature (DLST) and nighttime LST (NLST). The imagery utilized all had 8-day time intervals, but NDVI had a 250 m spatial resolution while the other products were 1000 m. These MODIS datasets were also assessed from both the Terra and Aqua satellites, with their differing overpass times, to document any differences. A follow-on analysis, using the Terra 250 m NDVI data as a benchmark, looked at the yield prediction utility of NDVI at two spatial scales (250 m vs. 1000 m), two time precisions (8-day vs. 16-day), and also assessed the Enhanced Vegetation Index (EVI, at 250 m, 16-day). The analyses spanned the major farming areas of the United States (US) from the summers of 2008-2013 and used annual county-level average crop yield data from the US Department of Agriculture as a basis. All crops, except rice, showed at least some positive correlations to each of the vegetation related indices in the middle of the growing season, with NDVI performing slightly better than FPAR. LAI was somewhat less strongly correlated and GPP weak overall. Conversely, some of the crops, particularly canola, corn, and soybeans, also showed negative correlations to DLST mid-summer. NLST, however, was never correlated to crop yield, regardless of the crop or seasonal timing. Differences between the Terra and Aqua results were found to be minimal. The 1000 m

  6. Detecting Climate Change and Its Impacts on Crop Yield in the Continental United States

    NASA Astrophysics Data System (ADS)

    Ge, Y.; Cai, X.

    2012-12-01

    Climatic variables, temperature and precipitation in particular, play critical roles in crop growth. Changes in climate, i.e., the change of mean and/or variance in climatic time series have brought up concerns for agriculture. Detecting past climate change and its impact is essential to understand the causes on what have already occurred. This study uses a novel change point detection method, which is based on Bayesian local posterior density and Pettitt test to detect multiple change points in a given time series, and to classify change patterns (graduate and step change) based on the final posterior probability density. The detection method is then applied to the United States Historical Climate Network (USHCN) covering thousands of sites; the change patterns of precipitation, and maximum, average and minimum temperature in crop growing periods and growing years are examined in details. The impacts of the identified climate changes on the yield of grain corn in the US are assessed. A regression model with climate variables is developed to model crop yield responses to the climate since 1970. Through various testing scenarios, it is found that the impacts of climate change on corn yield vary by region (Figure 1), temperature component (minimum, maximum or average), time periods for the assessment (crop growing period or year), and irrigated and rainfed crops. The change in minimum temperature has the largest impact on the gross corn yield over the Continental U.S among those climate variables; warming of maximum temperature boosts the gross corn yield, while warming of average temperature and minimum temperature slows it. In the Midwest, precipitation change has much larger impact on rainfed than on irrigated corn, which shows an evidence of irrigation adaptation to climate change in the region. Figure 1 shows the estimated impact of minimum temperature change (mean monthly minimum daily temperature in the growing season) in the growing season during 1970-2010 on

  7. Rain-fed fig yield as affected by rainfall distribution

    NASA Astrophysics Data System (ADS)

    Bagheri, Ensieh; Sepaskhah, Ali Reza

    2014-08-01

    Variable annual rainfall and its uneven distribution are the major uncontrolled inputs in rain-fed fig production and possibly the main cause of yield fluctuation in Istahban region of Fars Province, I.R. of Iran. This introduces a considerable risk in rain-fed fig production. The objective of this study was to find relationships between seasonal rainfall distribution and rain-fed fig production in Istahban region to determine the critical rainfall periods for rain-fed fig production and supplementary irrigation water application. Further, economic analysis for rain-fed fig production was considered in this region to control the risk of production. It is concluded that the monthly, seasonal and annual rainfall indices are able to show the effects of rainfall and its distribution on the rain-fed fig yield. Fig yield with frequent occurrence of 80 % is 374 kg ha-1. The internal rates of return for interest rate of 4, 8 and 12 % are 21, 58 and 146 %, respectively, that are economically feasible. It is concluded that the rainfall in spring especially in April and in December has negatively affected fig yield due to its interference with the life cycle of Blastophaga bees for pollination. Further, it is concluded that when the rainfall is limited, supplementary irrigation can be scheduled in March.

  8. Land application of sugar beet by-products: effects on nitrogen mineralization and crop yields.

    PubMed

    Kumar, Kuldip; Rosen, Carl J; Gupta, Satish C; McNearney, Matthew

    2009-01-01

    Land application of food processing wastes has become an acceptable practice because of the nutrient value of the wastes and potential cost savings in their disposal. Spoiled beets and pulp are among the main by-products generated by the sugar beet (Beta vulgaris L.) processing industry. Farmers commonly land apply these by-products at rates >224 Mg ha(-1) on a fresh weight basis. However, information on nutrient release in soils treated with these by-products and their subsequent impacts on crop yield is lacking. Field studies were conducted to determine the effects of sugar beet by-product application on N release and crop yields over two growing seasons. Treatments in the first year were two rates (224 and 448 Mg ha(-1) fresh weight) of pulp and spoiled beets and a nonfertilized control. In the second year after by-product application, the control treatment was fertilized with N fertilizer and an additional treatment was added as a nonfertilized control in buffer areas. Wheat (Triticum aestivum L.) was grown in the year of by-product application and sugar beet in the subsequent year. By-product treatments caused a significant reduction in wheat grain yield compared with the control. This was due to a decline in N availability as a result of immobilization. Based on microplots receiving 15N labeled beets, wheat took up <1% of spoiled beet-N (approximately 4.7 kg ha(-1)) during the year of by-product application. In the second cropping year, sugar beet root yields were significantly higher in the fertilized control and by-product treatments than the nonfertilized control. The lack of significant difference in sugar beet yield between the fertilized control and by-product treatments was likely due to the greater availability of N in the second year. Labeled 15N data also showed that the sugar beet crop recovered a 17% of sugar beet-N, an equivalent of 86 kg N ha(-1), during the second cropping year. There was no difference in sugar beet root yield, N uptake, or

  9. Nonlinear temperature effects indicate severe damages to U.S. crop yields under climate change.

    PubMed

    Schlenker, Wolfram; Roberts, Michael J

    2009-09-15

    The United States produces 41% of the world's corn and 38% of the world's soybeans. These crops comprise two of the four largest sources of caloric energy produced and are thus critical for world food supply. We pair a panel of county-level yields for these two crops, plus cotton (a warmer-weather crop), with a new fine-scale weather dataset that incorporates the whole distribution of temperatures within each day and across all days in the growing season. We find that yields increase with temperature up to 29 degrees C for corn, 30 degrees C for soybeans, and 32 degrees C for cotton but that temperatures above these thresholds are very harmful. The slope of the decline above the optimum is significantly steeper than the incline below it. The same nonlinear and asymmetric relationship is found when we isolate either time-series or cross-sectional variations in temperatures and yields. This suggests limited historical adaptation of seed varieties or management practices to warmer temperatures because the cross-section includes farmers' adaptations to warmer climates and the time-series does not. Holding current growing regions fixed, area-weighted average yields are predicted to decrease by 30-46% before the end of the century under the slowest (B1) warming scenario and decrease by 63-82% under the most rapid warming scenario (A1FI) under the Hadley III model. PMID:19717432

  10. Nonlinear temperature effects indicate severe damages to U.S. crop yields under climate change

    PubMed Central

    Schlenker, Wolfram; Roberts, Michael J.

    2009-01-01

    The United States produces 41% of the world's corn and 38% of the world's soybeans. These crops comprise two of the four largest sources of caloric energy produced and are thus critical for world food supply. We pair a panel of county-level yields for these two crops, plus cotton (a warmer-weather crop), with a new fine-scale weather dataset that incorporates the whole distribution of temperatures within each day and across all days in the growing season. We find that yields increase with temperature up to 29° C for corn, 30° C for soybeans, and 32° C for cotton but that temperatures above these thresholds are very harmful. The slope of the decline above the optimum is significantly steeper than the incline below it. The same nonlinear and asymmetric relationship is found when we isolate either time-series or cross-sectional variations in temperatures and yields. This suggests limited historical adaptation of seed varieties or management practices to warmer temperatures because the cross-section includes farmers' adaptations to warmer climates and the time-series does not. Holding current growing regions fixed, area-weighted average yields are predicted to decrease by 30–46% before the end of the century under the slowest (B1) warming scenario and decrease by 63–82% under the most rapid warming scenario (A1FI) under the Hadley III model. PMID:19717432

  11. Climatic impacts on winter wheat in Oklahoma and potential applications to climatic and crop yield prediction.

    PubMed

    Greene, J Scott; Maxwell, Erin

    2007-12-01

    Climatic anomalies can pose severe challenges for farmers and resource managers. This is particularly significant with respect to gradually developing anomalies such as droughts. The impact of the 1995-1996 drought on the Oklahoma wheat crop, and the possibility that predictive information might have reduced some of the losses, is examined through a combined modeling approach using climatological data and a crop growth model that takes into account an extensive range of soil, climatic, and plant variables. The results show potential outcomes and also illustrate the point at which all possible climatic outcomes were predicting a significantly low wheat yield. Based on anecdotal evidence of the 1995-1996 drought, which suggested that farmers who planted at different times experienced different yields, the model was run assuming a variety of different planting dates. Results indicate that there is indeed a noticeable difference in the modeled wheat yields given different planting dates. The information regarding effectiveness of planting date can be used in conjunction with current long-range forecasts to develop improved predictions for the current growing season. This approach produces information regarding the likelihood of extreme precipitation events and the impact on crop yield, which can provide a powerful tool to farmers and others during periods of drought or other climatic extremes. PMID:17578606

  12. Improvement of crop yield in dry environments: benchmarks, levels of organisation and the role of nitrogen.

    PubMed

    Sadras, V O; Richards, R A

    2014-05-01

    Crop yield in dry environments can be improved with complementary approaches including selecting for yield in the target environments, selecting for yield potential, and using indirect, trait- or genomic-based methods. This paper (i) outlines the achievements of direct selection for yield in improving drought adaptation, (ii) discusses the limitations of indirect approaches in the context of levels of organization, and (iii) emphasizes trade-offs and synergies between nitrogen nutrition and drought adaptation. Selection for yield in the water- and nitrogen-scarce environments of Australia improved wheat yield per unit transpiration at a rate of 0.12kg ha(-1) mm(-1) yr(-1); for indirect methods to be justified, they must return superior rates of improvement, achieve the same rate at lower cost or provide other cost-effective benefits, such as expanding the genetic basis for selection. Slow improvement of crop adaptation to water stress using indirect methods is partially related to issues of scale. Traits are thus classified into three broad groups: those that generally scale up from low levels of organization to the crop level (e.g. herbicide resistance), those that do not (e.g. grain yield), and traits that might scale up provided they are considered in a integrated manner with scientifically sound scaling assumptions, appropriate growing conditions, and screening techniques (e.g. stay green). Predicting the scalability of traits may help to set priorities in the investment of research efforts. Primary productivity in arid and semi-arid environments is simultaneously limited by water and nitrogen, but few attempts are made to target adaptation to water and nitrogen stress simultaneously. Case studies in wheat and soybean highlight biological links between improved nitrogen nutrition and drought adaptation. PMID:24638898

  13. Assessing the future of crop yield variability in the United States with downscaled climate projections (Invited)

    NASA Astrophysics Data System (ADS)

    Lobell, D. B.; Urban, D.

    2010-12-01

    One aspect of climate change of particular concern to farmers and food markets is the potential for increased year-to-year variability in crop yields. Recent episodes of food price increases following the Australian drought or Russian heat wave have heightened this concern. Downscaled climate projections that properly capture the magnitude of daily and interannual variability of weather can be useful for projecting future yield variability. Here we examine the potential magnitude and cause of changes in variability of corn yields in the United States up to 2050. Using downscaled climate projections from multiple models, we estimate a distribution of changes in mean and variability of growing season average temperature and precipitation. These projections are then fed into a model of maize yield that explicitly factors in the effect of extremely warm days. Changes in yield variability can result from a shift in mean temperatures coupled with a nonlinear crop response, a shift in climate variability, or a combination of the two. The results are decomposed into these different causes, with implications for future research to reduce uncertainties in projections of future yield variability.

  14. No-tillage and fertilization management on crop yields and nitrate leaching in North China Plain

    PubMed Central

    Huang, Manxiang; Liang, Tao; Wang, Lingqing; Zhou, Chenghu

    2015-01-01

    A field experiment was performed from 2003 to 2008 to evaluate the effects of tillage system and nitrogen management regimes on crop yields and nitrate leaching from the fluvo-aquic soil with a winter wheat (Triticum aestivum L.)–maize (Zea mays L.) double-cropping system. The tillage systems consisted of conventional tillage (CT) and no-tillage (NT). Three nitrogen management regimes were included: 270 kg N ha−1 of urea for wheat and 225 kg N ha−1 of urea for maize (U), 180 kg N ha−1 of urea and 90 kg N ha−1 of straw for wheat and 180 kg N of urea and 45 kg N ha−1 of straw for maize (S), 180 kg N ha−1 of urea and 90 kg N ha−1 of manure for wheat and 180 kg N ha−1 of urea and 45 kg N ha−1 of manure for maize (M). An array of tension-free pan lysimeters (50 cm × 75 cm) were installed (1.2 m deep) to measure water flow and -N movement. No significant effect of the N management regime on yields of winter wheat and maize grain was found in the 5-year rotation. Tillage systems had significant influences on -N leaching from the second year and thereafter interacted with N management regimes on -N loads during all maize seasons. The average yield-scaled -N leaching losses were in order of CTS < NTS< CTU < NTU yield-scaled -N leaching losses while sustaining crop grain yields. Considering the lower costs, NTS could be a potential alternative to decrease yield-scaled -N leaching losses and improve soil fertility while maintaining crop yield for the winter wheat–maize double-cropping systems in the North China Plain. PMID:25859321

  15. Biomass, extracted liquid yields, sugar content or seed yields of biofuel feedstocks as affected by fertilizer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Harvesting products from plants for conversion into renewable resources is increasing in importance. Determination of nutrition requirements for the applicable crops is necessary, especially in regions where the biofuel feedstock crops have not been grown historically. Sunflower (Helianthus annuus...

  16. Pleiotropic effects of herbicide-resistance genes on crop yield: a review.

    PubMed

    Darmency, Henri

    2013-08-01

    The rapid adoption of genetically engineered herbicide-resistant crop varieties (HRCVs)-encompassing 83% of all GM crops and nearly 8% of the worldwide arable area-is due to technical efficiency and higher returns. Other herbicide-resistant varieties obtained from genetic resources and mutagenesis have also been successfully released. Although the benefit for weed control is the main criteria for choosing HRCVs, the pleiotropic costs of genes endowing resistance have rarely been investigated in crops. Here the available data of comparisons between isogenic resistant and susceptible varieties are reviewed. Pleiotropic harmful effects on yield are reported in half of the cases, mostly with resistance mechanisms that originate from genetic resources and mutagenesis (atrazine in oilseed rape and millet, trifluralin in millet, imazamox in cotton) rather than genetic engineering (chlorsulfuron and glufosinate in some oilseed rape varieties, glyphosate in soybean). No effect was found for sethoxydim and bromoxynil resistance. Variable minor effects were found for imazamox, chlorsulfuron, glufosinate and glyphosate resistance. The importance of the breeding plan and the genetic background on the emergence of these effects is pointed out. Breeders' efforts to produce better varieties could compensate for the yield loss, which eliminates any possibility of formulating generic conclusions on pleiotropic effects that can be applied to all resistant crops. PMID:23457026

  17. Soil Eukaryotic Microorganism Succession as Affected by Continuous Cropping of Peanut - Pathogenic and Beneficial Fungi were Selected

    PubMed Central

    Chen, Mingna; Li, Xiao; Yang, Qingli; Chi, Xiaoyuan; Pan, Lijuan; Chen, Na; Yang, Zhen; Wang, Tong; Wang, Mian; Yu, Shanlin

    2012-01-01

    Peanut is an important oil crop worldwide and shows considerable adaptability but growth and yield are negatively affected by continuous cropping. Soil micro-organisms are efficient bio-indicators of soil quality and plant health and are critical to the sustainability of soil-based ecosystem function and to successful plant growth. In this study, 18S rRNA gene clone library analyses were employed to study the succession progress of soil eukaryotic micro-organisms under continuous peanut cultivation. Eight libraries were constructed for peanut over three continuous cropping cycles and its representative growth stages. Cluster analyses indicated that soil micro-eukaryotic assemblages obtained from the same peanut cropping cycle were similar, regardless of growth period. Six eukaryotic groups were found and fungi predominated in all libraries. The fungal populations showed significant dynamic change and overall diversity increased over time under continuous peanut cropping. The abundance and/or diversity of clones affiliated with Eurotiales, Hypocreales, Glomerales, Orbiliales, Mucorales and Tremellales showed an increasing trend with continuous cropping but clones affiliated with Agaricales, Cantharellales, Pezizales and Pyxidiophorales decreased in abundance and/or diversity over time. The current data, along with data from previous studies, demonstrated that the soil microbial community was affected by continuous cropping, in particular, the pathogenic and beneficial fungi that were positively selected over time, which is commonplace in agro-ecosystems. The trend towards an increase in fungal pathogens and simplification of the beneficial fungal community could be important factors contributing to the decline in peanut growth and yield over many years of continuous cropping. PMID:22808226

  18. Analyzing C-band SAR polarimetric information for LAI and crop yield estimations

    NASA Astrophysics Data System (ADS)

    Molijn, Ramses A.; Iannini, Lorenzo; Mousivand, Ali; Hanssen, Ramon F.

    2014-10-01

    In this study, space remote sensing data and crop specific information from the ESA-led AgriSAR 2009 campaign are used for studying the profiles of C-band SAR backscatter signals and multispectral-based leaf area index (LAI) over the growth period of canola, pea and wheat. In addition, the correlations between radar backscatter parameters and the crop yields were analyzed, based on extracted statistics of temporal profiles. The results show that the HV backscatter and LAI are correlated differently before and after LAI peak. In addition, the coefficient of determination between peakrelated statistics from polarimetric indicator profiles and yield for pea fields can reach up to 0.68, and for canola and wheat up to 0.47 and 0.5, respectively. HV backscatter and coherence between HH and VV are most.

  19. More uneven distributions overturn benefits of higher precipitation for crop yields

    NASA Astrophysics Data System (ADS)

    Fishman, Ram

    2016-02-01

    Climate change is expected to lead to more uneven temporal distributions of precipitation, but the impacts on human systems are little studied. Most existing, statistically based agricultural climate change impact projections only account for changes in total precipitation, ignoring its intra-seasonal distribution, and conclude that in places that will become wetter, agriculture will benefit. Here, an analysis of daily rainfall and crop yield data from across India (1970-2003), where a fifth of global cereal supply is produced, shows that decreases in the number of rainy days have robust negative impacts that are large enough to overturn the benefits of increased total precipitation for the yields of most major crops. As an illustration, the net, mid 21st century projection for rice production shifts from +2% to -11% when changes in distribution are also accounted for, independently of additional negative impacts of rising temperatures.

  20. Yield, biomass, and uptake of crop plants irrigated with TNT and RDX contaminated water

    SciTech Connect

    Simini, M.; Checkai, R.T.

    1995-12-31

    Crops grown in site-collected soil were irrigated with water containing 2,4,6-trinitrotoluene (TNT) and cyclotrimethylenetrinitramine (RDX) to simulate field conditions at Cornhusker Army Ammunition Plant, Nebraska. Pots were watered in an environment-controlled greenhouse to field capacity throughout the life-cycle of the crop with 2, 20, and 100 ppb RDX; 2,100, and 800ppb TNT; 100ppb RDX + 800ppb TNT; or uncontaminated water. Yield and biomass of tomato fruit, bush bean fruit, corn stover, and soybean seeds were significantly (p = 0.05) less when irrigated with the RDX + TNT treatment compared to controls. Lettuce leaves and radish root yield and biomass were unaffected by treatment level. Soil loading of RDX and TNT in response to evapotranspiration was greatest for tomato, corn, soybean, bush bean, and least for radish and lettuce. Plant tissue contaminant concentrations will be presented and discussed.

  1. Research issues in determining the effects of changing climate variability on crop yields

    SciTech Connect

    Mearns, L.O.

    1995-12-31

    The authors discusses three aspects of research necessary for investigating possible effects of changes in climatic variability on crop yields. Additional information on changed variability effects is needed to further elucidate uncertainties in the knowledge of possible impacts of climate change on agriculture. First, sensitivity analyses of crop responses to shifting change in variability must be performed. Second, investigations of how climatic variability may change under perturbed climate conditions should be undertaken. If one has some confidence in estimates of how variability may change, then a third research task is the formation of climate change scenarios that incorporate changes in climatic variability and their application to crop-climate models to determine crop responses. In this chapter, these research tasks are discussed regarding one climate variable, precipitation. The authors summarize two research projects that have been undertaken to investigate the sensitivity of the CERES-wheat (Triticum aestivum L.) crop model to changes in climatic variability, on daily to annual time scales, for sites in the central Great Plains. He also provides an example of determining possible changes in daily variability of precipitation through analysis of results from two regional climate model experiments, and then go on to describe an example of forming a climate change scenario that incorporates changes in daily precipitation variability estimated from the regional model runs. 27 refs., 9 figs., 1 tab.

  2. For assessing yields under extreme climatic events using crop simulation models: aerosol layer effects on growth and yield of wheat, rice, and sugarcane

    NASA Astrophysics Data System (ADS)

    Kalra, Naveen; Chakraborty, D.; Sahoo, R. N.; Sehgal, V. K.; Singh, Manish

    2006-12-01

    Aerosol presence reduces sunshine hours and the amount of radiation received. The extent of reduction in radiation during this extreme event (January-March 1999) was relatively lower, as the extent of the diffused radiation increases. During this time, the reduction ranged from 5-12%. The differential response of the crops (wheat, rice and sugarcane) under changed proportion of direct and diffused radiation due to haze was seen through using crop simulation models (WTGROWS for wheat, DSSAT for rice and sugarcane). The growing conditions were optimal. Regions chosen for simulation were north-west India for wheat, coastal and southern regions for rice and north-eastern, western and southern regions for sugarcane. Simulation results were obtained in terms of phenology, biomass and economic yield at harvest. There was slight reduction in the yield of these three crops due to reduction in the radiation, but coupled weather changes (lowering of temperature, etc.) due to cloudy condition could benefit the crops through phenology modifications and other crop process activities, which can some times give higher yields of crops under the aerosol layer when compared to no haze layer situation. Diffused radiation is more photo-synthetically active, and this feature has still to be included in most of the existing crop growth models, as the existing crop models do not differentiate between direct and diffused radiation. The scope of using remote sensing for assessing the haze layer (spatial and temporal extent) could be employed in the crop simulation models for regional impact analysis.

  3. Using the CLM Crop Model to assess the impacts of changes in Climate, Atmospheric CO2, Irrigation, Fertilizer and Geographic Distribution on Historical and Future Crop Yields

    NASA Astrophysics Data System (ADS)

    Lawrence, P.

    2015-12-01

    Since the start of the green revolution global crop yields have increased linearly for most major cereal crops, so that present day global values are around twice those of the 1960s. The increase in crop yields have allowed for large increases in global agricultural production without correspondingly large increases in cropping area. Future projections under the Shared Socio-economic Pathways (SSP) framework and other assessments result in increases of global crop production of greater than 100% by the year 2050. In order to meet this increased agricultural demand within the available arable land, future production gains need to be understood in terms of the yield changes due to changes in climate, atmospheric CO2, and adaptive management such as irrigation and fertilizer application. In addition to the changes in crop yield, future agricultural demand will need to be met through increasing cropping areas into what are currently marginal lands at the cost of existing forests and other natural ecosystems. In this study we assess the utility of the crop model within the Community Land Model (CLM Crop) to provide both historical and future guidance on changes in crop yields under a range of global idealized crop modeling experiments. The idealized experiments follow the experimental design of the AgMIP Global Gridded Crop Model Intercomparison (GGCMI) in which CLM Crop is a participating model. The idealized experiments consist of global crop simulations for Cotton, Maize, Rice, Soy, Sugarcane, and Wheat under various climate, atmospheric CO2 levels, irrigation prescription, and nitrogen fertilizer application. The time periods simulated for the experiments are for the Historical period (1901 - 2005), and for the two Representative Concentration Pathways of RCP 4.5 and RCP 8.5 (2006 - 2100). Each crop is simulated on all land grid cells globally for each time period with atmospheric forcing that is a combination of: 1. transient climate and CO2; 2. transient climate

  4. A Study of Estimating Winter Wheat Yields by Using Satellite Data Assimilation with Crop Growth Model

    NASA Astrophysics Data System (ADS)

    Kuwata, K.

    2013-12-01

    Accurate information of crop yield is important for production planning in agriculture. Crop growth model is a effective tool to comprehend crop growth situation. Accordingly, we use the MOSIS data for two types of utilization to provide necessary information for DSSAT. The objective of this study is developing a method of estimating winter wheat yield without adequate information of the field. The first use is estimation of solar radiation, which is required as input data into DSSAT. Since MODIS is observing the earth everyday, solar radiation can be estimated in a region where a climate observation system is not developed. The second use is data assimilation that provides appropriate parameter of cultivation management to DSSAT. MODIS LAI and Dry Matter Production (DMP) estimated from MODIS GPP are assimilated into DSSAT. Before developing data assimilation, we have accomplished sensitivity analysis of DSSAT. As the result of the analysis, we found that planting date and amount of applied fertilizer have correlated strongly with LAI and Dry Matter (DM) for specific growth period. Based on the result, we estimated winter wheat yield by assimilating MODIS LAI and DMP observed during the specific period. In contrast, previous study estimated crop yield by assimilating satellite data observed for the whole growth period. Three different assimilation schemes were tested to verify the accuracy of our method. Our results showed that the estimated winter wheat yield agreed very well with the Japanese agricultural experiment station data. Among different assimilating scenarios, the best result was obtained when MODIS LAI and DMP observed for specific growth period; the Root Square Mean Error (RMSE) was 406.52 kg ha2. The distribution map of full year incident PAR in Asia. Estimated Winter Wheat Yield in Japan In the case 1, detail information gathered by experiment reports.In the case 2, all management parameters are determined by reference to cultivation manuals.In the

  5. Sulfuric acid rain effects on crop yield and foliar injury. Final report

    SciTech Connect

    Lee, J.J.; Neely, G.E.; Perrigan, S.C.

    1980-01-01

    A study was undertaken to determine the relative sensitivity of major U.S. crops to sulfuric acid rain. Plants were grown under controlled environmental conditions and exposed to simulated acid rain of three sulfuric acid concentrations (pH 3.0, 3.5, 4.0) or to a control rain (pH 5.7). Injury to foliage and effects on yield were common responses to acid rain. However, foliar injury was not a good indicator of effects on yield.

  6. SWAT Ungauged: Hydrological Budget and Crop Yield Predictions in the Upper Mississippi River Basin

    SciTech Connect

    R. Srinivasan,; X. Zhang,; J. Arnold,

    2010-01-01

    Physically based, distributed hydrologic models are increasingly used in assessments of water resources, best management practices, and climate and land use changes. Model performance evaluation in ungauged basins is an important research topic. In this study, we propose a framework for developing Soil and Water Assessment Tool (SWAT) input data, including hydrography, terrain, land use, soil, tile, weather, and management practices, for the Upper Mississippi River basin (UMRB). We also present a performance evaluation of SWAT hydrologic budget and crop yield simulations in the UMRB without calibration. The uncalibrated SWAT model ably predicts annual streamflow at 11 USGS gauges and crop yield at a four-digit hydrologic unit code (HUC) scale. For monthly streamflow simulation, the performance of SWAT is marginally poor compared with that of annual flow, which may be due to incomplete information about reservoirs and dams within the UMRB. Further validation shows that SWAT can predict base flow contribution ratio reasonably well. Compared with three calibrated SWAT models developed in previous studies of the entire UMRB, the uncalibrated SWAT model presented here can provide similar results. Overall, the SWAT model can provide satisfactory predictions on hydrologic budget and crop yield in the UMRB without calibration. The results emphasize the importance and prospects of using accurate spatial input data for the physically based SWAT model. This study also examines biofuel-biomass production by simulating all agricultural lands with switchgrass, producing satisfactory results in estimating biomass availability for biofuel production.

  7. Influence of cadmium on dry matter yield, micronutrient content and its uptake in some crops.

    PubMed

    Khurana, M P S; Jhanji, Shalini

    2014-09-01

    The study was conducted to evaluate the accumulation pattern of cadmium (Cd) and its tolerance in different crops grown on sewage irrigated soils with differentCd levels. Growth, yield, uptake and tolerance of maize, raya, berseem and spinach were assessed to different levels of Cd ranging from 0-40 mg kg(-1) soil. Significant reduction in dry matter yield in raya was observed at 20 mg Cd kg(-1) soil where as for other crops it was 10 mg Cd kg(-1) soil. The quadratic models seem to give the best description of variation in dry matter yield with Cd levels as revealed by significant coefficient of determination (R2 > or = 90). Cadmium content and uptake varied in the following order: raya > spinach > maize > berseem. Raya could tolerate high levels of Cd as compared to other crops. Conversely, berseem and maize which showed reduced ability to absorb or translocate Cd for genetic reasons compared to raya and spinach be preferred for growing on sewage irrigated soils or area having increased Cd-levels. The relationship of Cd with other micronutrients was variable. PMID:25204060

  8. Paddy crop yield estimation in Kashmir Himalayan rice bowl using remote sensing and simulation model.

    PubMed

    Muslim, Mohammad; Romshoo, Shakil Ahmad; Rather, A Q

    2015-06-01

    The Kashmir Himalayan region of India is expected to be highly prone to the change in agricultural land use because of its geo-ecological fragility, strategic location vis-à-vis the Himalayan landscape, its trans-boundary river basins, and inherent socio-economic instabilities. Food security and sustainability of the region are thus greatly challenged by these impacts. The effect of future climate change, increased competition for land and water, labor from non-agricultural sectors, and increasing population adds to this complex problem. In current study, paddy rice yield at regional level was estimated using GIS-based environment policy integrated climate (GEPIC) model. The general approach of current study involved combining regional level crop database, regional soil data base, farm management data, and climatic data outputs with GEPIC model. The simulated yield showed that estimated production to be 4305.55 kg/ha (43.05 q h(-1)). The crop varieties like Jhelum, K-39, Chenab, China 1039, China-1007, and Shalimar rice-1 grown in plains recorded average yield of 4783.3 kg/ha (47.83 q ha(-1)). Meanwhile, high altitude areas with varieties like Kohsaar, K-78 (Barkat), and K-332 recorded yield of 4102.2 kg/ha (41.02 q ha(-1)). The observed and simulated yield showed a good match with R (2) = 0.95, RMSE = 132.24 kg/ha, respectively. PMID:25937498

  9. Advances in regional crop yield estimation over the United States using satellite remote sensing data

    NASA Astrophysics Data System (ADS)

    Johnson, D. M.; Dorn, M. F.; Crawford, C.

    2015-12-01

    Since the dawn of earth observation imagery, particularly from systems like Landsat and the Advanced Very High Resolution Radiometer, there has been an overarching desire to regionally estimate crop production remotely. Research efforts integrating space-based imagery into yield models to achieve this need have indeed paralleled these systems through the years, yet development of a truly useful crop production monitoring system has been arguably mediocre in coming. As a result, relatively few organizations have yet to operationalize the concept, and this is most acute in regions of the globe where there are not even alternative sources of crop production data being collected. However, the National Agricultural Statistics Service (NASS) has continued to push for this type of data source as a means to complement its long-standing, traditional crop production survey efforts which are financially costly to the government and create undue respondent burden on farmers. Corn and soybeans, the two largest field crops in the United States, have been the focus of satellite-based production monitoring by NASS for the past decade. Data from the Moderate Resolution Imaging Spectroradiometer (MODIS) has been seen as the most pragmatic input source for modeling yields primarily based on its daily revisit capabilities and reasonable ground sample resolution. The research methods presented here will be broad but provides a summary of what is useful and adoptable with satellite imagery in terms of crop yield estimation. Corn and soybeans will be of particular focus but other major staple crops like wheat and rice will also be presented. NASS will demonstrate that while MODIS provides a slew of vegetation related products, the traditional normalized difference vegetation index (NDVI) is still ideal. Results using land surface temperature products, also generated from MODIS, will also be shown. Beyond the MODIS data itself, NASS research has also focused efforts on understanding a

  10. Crop suitability monitoring for improved yield estimations with 100m PROBA-V data

    NASA Astrophysics Data System (ADS)

    Özüm Durgun, Yetkin; Gilliams, Sven; Gobin, Anne; Duveiller, Grégory; Djaby, Bakary; Tychon, Bernard

    2015-04-01

    This study has been realised within the framework of a PhD targeting to advance agricultural monitoring with improved yield estimations using SPOT VEGETATION remotely sensed data. For the first research question, the aim was to improve dry matter productivity (DMP) for C3 and C4 plants by adding a water stress factor. Additionally, the relation between the actual crop yield and DMP was studied. One of the limitations was the lack of crop specific maps which leads to the second research question on 'crop suitability monitoring'. The objective of this work is to create a methodological approach based on the spectral and temporal characteristics of PROBA-V images and ancillary data such as meteorology, soil and topographic data to improve the estimation of annual crop yields. The PROBA-V satellite was launched on 6th May 2013, and was designed to bridge the gap in space-borne vegetation measurements between SPOT-VGT (March 1998 - May 2014) and the upcoming Sentinel-3 satellites scheduled for launch in 2015/2016. PROBA -V has products in four spectral bands: BLUE (centred at 0.463 µm), RED (0.655 µm), NIR (0.845 µm), and SWIR (1.600 µm) with a spatial resolution ranging from 1km to 300m. Due to the construction of the sensor, the central camera can provide a 100m data product with a 5 to 8 days revisiting time. Although the 100m data product is still in test phase a methodology for crop suitability monitoring was developed. The multi-spectral composites, NDVI (Normalised Difference Vegetation Index) (NIR_RED/NIR+RED) and NDII (Normalised Difference Infrared Index) (NIR-SWIR/NIR+SWIR) profiles are used in addition to secondary data such as digital elevation data, precipitation, temperature, soil types and administrative boundaries to improve the accuracy of crop yield estimations. The methodology is evaluated on several FP7 SIGMA test sites for the 2014 - 2015 period. Reference data in the form of vector GIS with boundaries and cover type of agricultural fields are

  11. The global impact of ozone on agricultural crop yields under current and future air quality legislation

    NASA Astrophysics Data System (ADS)

    Van Dingenen, Rita; Dentener, Frank J.; Raes, Frank; Krol, Maarten C.; Emberson, Lisa; Cofala, Janusz

    In this paper we evaluate the global impact of surface ozone on four types of agricultural crop. The study is based on modelled global hourly ozone fields for the year 2000 and 2030, using the global 1°×1° 2-way nested atmospheric chemical transport model (TM5). Projections for the year 2030 are based on the relatively optimistic "current legislation (CLE) scenario", i.e. assuming that currently approved air quality legislation will be fully implemented by the year 2030, without a further development of new abatement policies. For both runs, the relative yield loss due to ozone damage is evaluated based on two different indices (accumulated concentration above a 40 ppbV threshold and seasonal mean daytime ozone concentration respectively) on a global, regional and national scale. The cumulative metric appears to be far less robust than the seasonal mean, while the seasonal mean shows satisfactory agreement with measurements in Europe, the US, China and Southern India and South-East Asia. Present day global relative yield losses are estimated to range between 7% and 12% for wheat, between 6% and 16% for soybean, between 3% and 4% for rice, and between 3% and 5% for maize (range resulting from different metrics used). Taking into account possible biases in our assessment, introduced through the global application of "western" crop exposure-response functions, and through model performance in reproducing ozone-exposure metrics, our estimates may be considered as being conservative. Under the 2030 CLE scenario, the global situation is expected to deteriorate mainly for wheat (additional 2-6% loss globally) and rice (additional 1-2% loss globally). India, for which no mitigation measures have been assumed by 2030, accounts for 50% of these global increase in crop yield loss. On a regional-scale, significant reductions in crop losses by CLE-2030 are only predicted in Europe (soybean) and China (wheat). Translating these assumed yield losses into total global economic

  12. Impacts of temperature increase and change in precipitation pattern on crop yield and yield quality of barley.

    PubMed

    Högy, Petra; Poll, Christian; Marhan, Sven; Kandeler, Ellen; Fangmeier, Andreas

    2013-02-15

    Spring barley was grown in a field experiment under moderately elevated soil temperature and changed summer precipitation (amount and frequency). Elevated temperature affected the performance and grain quality characteristics more significant than changes in rainfall. Except for the decrease in thousand grain weight, warming had no impacts on aboveground biomass and grain yield traits. In grains, several proteinogenic amino acids concentrations were increased, whereas their composition was only slightly altered. Concentration and yield of total protein remained unaffected under warming. The concentrations of total non-structural carbohydrates, starch, fructose and raffinose were lower in plants grown at high temperatures, whereas maltose was higher. Crude fibre remained unaffected by warming, whereas concentrations of lipids and aluminium were reduced. Manipulation of precipitation only marginally affected barley grains: amount reduction increased the concentrations of several minerals (sodium, copper) and amino acids (leucine). The projected climate changes may most likely affect grain quality traits of interest for different markets and utilisation requirements. PMID:23194550

  13. A Crop Simulation Model for Prediction of Yield and Fate of Nitrogen in Irrigated Potato Rotation Cropping System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Simulation models are valuable tools to evaluate the soil processes, crop growth and production under varied agroclimatic and management conditions. In this study, an upgraded potato crop growth simulation model (CSPotato) was integrated with a multi-year, multi-crop simulation model (CropSystVB)....

  14. Drought Effects on Agricultural Yield: Comparison Across Regions and Crop Types

    NASA Astrophysics Data System (ADS)

    Daryanto, S.; Wang, L.; Jacinthe, P. A.

    2014-12-01

    Global agricultural production is dominated by rainfed agriculture, and is therefore prone to disruption from climate extreme weathers. These uncertainties become more problematic when considering the projection of increased drought frequency suggested by several climate models for various world regions. Curiously, few regional analyses of drought impact of food production have been attempted. We collated and analyzed data from the last 25 years to disentangle the effects of drought (i.e. timing, intensity and duration) on agricultural production in different eco-regions and with varying crop types. Our preliminary results suggested greater yield reduction in annual (-21.5%) than perennial plants (-16%), in C4 (-21%) compared to C3 crops (-17%), and when drought occurred during generative (i.e. flowering until maturity; -16.5%) than vegetative stage (-15.5%). Although drought caused similar amounts of yield reduction in both tropical and subtropical regions (i.e. -17%), it carries a greater food security risk in the tropics due to inherently low productivity (i.e. less than half than in the subtropical regions). Consequently, cultivating drought-resistant C3 perennial plants (e.g. sweet potato and cassava) in the tropics could prove a viable adaptive strategy to mitigate the effects of climate variability. In addition, these crops have limited input requirements, are well adapted to nutrient-poor Oxisols and Ultisols of the tropics, and generally outyield cereal crops in the region. Our analysis is ongoing and needs to take into account agronomic traits (e.g. water requirement), as well as the energy and nutritional values (e.g. protein, minerals) of alternative crops. Our results could inform the selection and development of new cultivars for the drought-prone regions of the world.

  15. CESM-simulated 21st Century Changes in Large Scale Crop Water Requirements and Yields

    NASA Astrophysics Data System (ADS)

    Levis, S.; Badger, A.; Drewniak, B. A.; O'Neill, B. C.; Ren, X.

    2014-12-01

    We assess potential changes in crop water requirements and corresponding yields relative to the late 20th century in major crop producing regions of the world by using the Community Land Model (CLM) driven with 21st century meteorology from RCP8.5 and RCP4.5 Community Earth System Model (CESM) simulations. The RCP4.5 simulation allows us to explore the potential for averted societal impacts when compared to the RCP8.5 simulation. We consider the possibility for increased yields and improved water use efficiency under conditions of elevated atmospheric CO2 due to the CO2 fertilization effect (also known as concentration-carbon feedback). We address uncertainty in the current understanding of plant CO2 fertilization by repeating the simulations with and without the CO2 fertilization effect. Simulations without CO2 fertilization represent the radiative effect of elevated CO2 (i.e., warming) without representing the physiological effect of elevated CO2 (enhanced carbon uptake and increased water use efficiency by plants during photosynthesis). Preliminary results suggest that some plants may suffer from increasing heat and drought in much of the world without the CO2 fertilization effect. On the other hand plants (especially C3) tend to grow more with less water when models include the CO2 fertilization effect. Performing 21st century simulations with and without the CO2 fertilization effect brackets the potential range of outcomes. In this work we use the CLM crop model, which includes specific crop types that differ from the model's default plant functional types in that the crops get planted, harvested, and potentially fertilized and irrigated according to algorithms that attempt to capture human management decisions. We use an updated version of the CLM4.5 that includes cotton, rice, and sugarcane, spring wheat, spring barley, and spring rye, as well as temperate and tropical maize and soybean.

  16. The Economic Impact of Climate, CO2, and Tropospheric Ozone Effects on Crop Yields in China, the US, and Europe

    NASA Astrophysics Data System (ADS)

    Reilly, J. M.; Felzer, B. S.; Paltsev, S.; Melillo, J. M.; Prinn, R. G.; Wang, C.; Sokolov, A. P.; Wang, X.

    2004-12-01

    Multiple environmental changes that may occur over the next century will affect crop productivity. Some of these effects are likely to be positive (CO2 fertilization), some negative (tropospheric ozone damage), and some may be either positive or negative (temperature and precipitation). Climate effects may operate in either direction because the direction of change may differ across regions (more precipitation in some areas and less in others) and warming may increase growing season lengths in cold-limited growing areas while acting as a detriment to productivity in areas with already high temperatures. Previous work has shown the effects of these combined environmental changes on carbon sequestration in natural and managed systems, and valued these effects in terms of avoided costs of fossil fuel carbon abatement. The more direct and obvious economic effect, however, is the changes in crop yields implied by these vegetation effects. Here we use the MIT Integrated Global Systems Model (IGSM) to analyze the potential economic impact of changes in crop yields. For this work we have augmented the Emissions Prediction and Policy Analysis (EPPA) model by further disaggregating the agricultural sector. This allows us to simulate economic effects of changes in yield (i.e. the productivity of cropland) on the regional economies of the world, including impacts on agricultural trade. The EPPA model includes multiple channels of market-based adaptation, including input substitution and trade. We are thus able to examine the extent to which market forces contribute toward adaptation and thus modify the initial yield effects. We examine multiple scenarios where tropospheric ozone precursors are controlled or not, and where greenhouse gas emissions are abated or not. This allows us to consider how these policies interact. We focus on China, the US, and Europe which are currently regions with high levels of tropospheric ozone damage. We find significant negative effects of

  17. Sustainable Management in Crop Monocultures: The Impact of Retaining Forest on Oil Palm Yield

    PubMed Central

    Edwards, Felicity A.; Edwards, David P.; Sloan, Sean; Hamer, Keith C.

    2014-01-01

    Tropical agriculture is expanding rapidly at the expense of forest, driving a global extinction crisis. How to create agricultural landscapes that minimise the clearance of forest and maximise sustainability is thus a key issue. One possibility is protecting natural forest within or adjacent to crop monocultures to harness important ecosystem services provided by biodiversity spill-over that may facilitate production. Yet this contrasts with the conflicting potential that the retention of forest exports dis-services, such as agricultural pests. We focus on oil palm and obtained yields from 499 plantation parcels spanning a total of ≈23,000 ha of oil palm plantation in Sabah, Malaysian Borneo. We investigate the relationship between the extent and proximity of both contiguous and fragmented dipterocarp forest cover and oil palm yield, controlling for variation in oil palm age and for environmental heterogeneity by incorporating proximity to non-native forestry plantations, other oil palm plantations, and large rivers, elevation and soil type in our models. The extent of forest cover and proximity to dipterocarp forest were not significant predictors of oil palm yield. Similarly, proximity to large rivers and other oil palm plantations, as well as soil type had no significant effect. Instead, lower elevation and closer proximity to forestry plantations had significant positive impacts on oil palm yield. These findings suggest that if dipterocarp forests are exporting ecosystem service benefits or ecosystem dis-services, that the net effect on yield is neutral. There is thus no evidence to support arguments that forest should be retained within or adjacent to oil palm monocultures for the provision of ecosystem services that benefit yield. We urge for more nuanced assessments of the impacts of forest and biodiversity on yields in crop monocultures to better understand their role in sustainable agriculture. PMID:24638038

  18. Sustainable management in crop monocultures: the impact of retaining forest on oil palm yield.

    PubMed

    Edwards, Felicity A; Edwards, David P; Sloan, Sean; Hamer, Keith C

    2014-01-01

    Tropical agriculture is expanding rapidly at the expense of forest, driving a global extinction crisis. How to create agricultural landscapes that minimise the clearance of forest and maximise sustainability is thus a key issue. One possibility is protecting natural forest within or adjacent to crop monocultures to harness important ecosystem services provided by biodiversity spill-over that may facilitate production. Yet this contrasts with the conflicting potential that the retention of forest exports dis-services, such as agricultural pests. We focus on oil palm and obtained yields from 499 plantation parcels spanning a total of ≈23,000 ha of oil palm plantation in Sabah, Malaysian Borneo. We investigate the relationship between the extent and proximity of both contiguous and fragmented dipterocarp forest cover and oil palm yield, controlling for variation in oil palm age and for environmental heterogeneity by incorporating proximity to non-native forestry plantations, other oil palm plantations, and large rivers, elevation and soil type in our models. The extent of forest cover and proximity to dipterocarp forest were not significant predictors of oil palm yield. Similarly, proximity to large rivers and other oil palm plantations, as well as soil type had no significant effect. Instead, lower elevation and closer proximity to forestry plantations had significant positive impacts on oil palm yield. These findings suggest that if dipterocarp forests are exporting ecosystem service benefits or ecosystem dis-services, that the net effect on yield is neutral. There is thus no evidence to support arguments that forest should be retained within or adjacent to oil palm monocultures for the provision of ecosystem services that benefit yield. We urge for more nuanced assessments of the impacts of forest and biodiversity on yields in crop monocultures to better understand their role in sustainable agriculture. PMID:24638038

  19. Identification of saline soils with multi-year remote sensing of crop yields

    SciTech Connect

    Lobell, D; Ortiz-Monasterio, I; Gurrola, F C; Valenzuela, L

    2006-10-17

    Soil salinity is an important constraint to agricultural sustainability, but accurate information on its variation across agricultural regions or its impact on regional crop productivity remains sparse. We evaluated the relationships between remotely sensed wheat yields and salinity in an irrigation district in the Colorado River Delta Region. The goals of this study were to (1) document the relative importance of salinity as a constraint to regional wheat production and (2) develop techniques to accurately identify saline fields. Estimates of wheat yield from six years of Landsat data agreed well with ground-based records on individual fields (R{sup 2} = 0.65). Salinity measurements on 122 randomly selected fields revealed that average 0-60 cm salinity levels > 4 dS m{sup -1} reduced wheat yields, but the relative scarcity of such fields resulted in less than 1% regional yield loss attributable to salinity. Moreover, low yield was not a reliable indicator of high salinity, because many other factors contributed to yield variability in individual years. However, temporal analysis of yield images showed a significant fraction of fields exhibited consistently low yields over the six year period. A subsequent survey of 60 additional fields, half of which were consistently low yielding, revealed that this targeted subset had significantly higher salinity at 30-60 cm depth than the control group (p = 0.02). These results suggest that high subsurface salinity is associated with consistently low yields in this region, and that multi-year yield maps derived from remote sensing therefore provide an opportunity to map salinity across agricultural regions.

  20. Soil carbon and nitrogen affected by perennial grass, cover crop, and nitrogen fertilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil C and N sequestration and the potential for N leaching can be influenced by the type of perennial grass, cover crop, and N fertilization due to differences in crop yields and the amount of residue returned to the soil. We evaluated the effects of the combinations of perennial grasses (energy ca...

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Effect of nutrient management planning on crop yield, nitrate leaching and sediment loading in Thomas Brook watershed.

    PubMed

    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 [Formula: see text] 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., [Formula: see text] 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 [Formula: see text] 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 [Formula: see text] leaching while balancing impacts on crop yields within the watershed. PMID:23943075

  3. Effect of crop residue harvest on long-term crop yield, soil erosion, and carbon balance: tradeoffs for a sustainable bioenergy feedstock

    SciTech Connect

    Gregg, Jay S.; Izaurralde, Roberto C.

    2010-08-26

    Agricultural residues are a potential feedstock for bioenergy production, if residue harvest can be done sustainably. The relationship between crop residue harvest, soil erosion, crop yield and carbon balance was modeled with the Erosion Productivity Impact Calculator/ Environment Policy Integrated Climate (EPIC) using a factorial design. Four crop rotations (winter wheat [Triticum aestivum (L.)] – sunflower [Helianthus annuus]; spring wheat [Triticum aestivum (L.)] – canola [Brassica napus]; corn [Zea mays L.] – soybean [Glycine max (L.) Merr.]; and cotton [Gossypium hirsutum] – peanut [Arachis hypogaea]) were simulated at four US locations each, under different topographies (0-10% slope), and management practices [crop residue removal rates (0-75%), conservation practices (no till, contour cropping, strip cropping, terracing)].

  4. Assimilation of remote sensing data into crop growth model to improve the estimation of regional winter wheat yield

    NASA Astrophysics Data System (ADS)

    Liu, Chaoshun; Gao, Wei; Liu, Pudong; Sun, Zhibin

    2014-10-01

    Accurate regional crop growth monitoring and yield prediction is very critical for the national food security assessment and sustainable development of agriculture, especially for China, which has the largest population in the world. Remote sensing data and crop growth model have been successfully used in the crop production prediction. However, both of them have inherent limitation and uncertainty. The data assimilation method which combines crop growth model and remotely sensed data has been proven to be the most effective method in regional yield estimation. The aim of this paper is to improve the estimation of regional winter wheat yield of crop growth model by using data assimilation schemes with Ensemble Kalman Filter (EnKF) algorithm. WOrld FOod STudies (WOFOST) crop growth model was chosen as the crop growth model which was calibrated and validated by the field measured data. MODIS Leaf Area Index (LAI) values were used as remote sensing observations to adjust the LAI simulated by the WOFOST model based on EnKF. The results illustrate that the EnKF algorithm has significantly improved the regional winter wheat yield estimates over the WOFOST simulation without assimilation in both potential and water-limited modes. Although this study clearly implies that the assimilation of the remotely sensed data into crop growth model with EnKF algorithm has the potential to improve the prediction of regional crop yield and has great potential in agricultural applications, high resolution meteorological data and detailed crop field management are necessary to reach a high accuracy of regional crop yield estimation.

  5. Ecoinformatics Can Reveal Yield Gaps Associated with Crop-Pest Interactions: A Proof-of-Concept

    PubMed Central

    Rosenheim, Jay A.; Meisner, Matthew H.

    2013-01-01

    Farmers and private consultants execute a vast, decentralized data collection effort with each cropping cycle, as they gather pest density data to make real-time pest management decisions. Here we present a proof of concept for an ecoinformatics approach to pest management research, which attempts to harness these data to answer questions about pest-crop interactions. The impact of herbivory by Lygus hesperus on cotton is explored as a case study. Consultant-derived data satisfied a ‘positive control’ test for data quality by clearly resolving the expected negative relationship between L. hesperus density and retention of flower buds. The enhanced statistical power afforded by the large ecoinformatics dataset revealed an early-season window of crop sensitivity, during which L. hesperus densities as low as 1-2 per sample were associated with yield loss. In contrast, during the mid-season insecticide use by farmers was often unnecessary, as cotton compensated fully for moderate L. hesperus densities. Because the dataset emerged from the commercial production setting, it also revealed the limited degree to which farmers were willing to delay crop harvest to provide opportunities for compensatory fruiting. Observational approaches to pest management research have strengths and weaknesses that complement those of traditional, experimental approaches; combining these methods can contribute to enhanced agricultural productivity. PMID:24260408

  6. Increased Phytochrome B Alleviates Density Effects on Tuber Yield of Field Potato Crops1

    PubMed Central

    Boccalandro, Hernán E.; Ploschuk, Edmundo L.; Yanovsky, Marcelo J.; Sánchez, Rodolfo A.; Gatz, Christiane; Casal, Jorge J.

    2003-01-01

    The possibility that reduced photomorphogenic responses could increase field crop yield has been suggested often, but experimental support is still lacking. Here, we report that ectopic expression of the Arabidopsis PHYB (phytochrome B) gene, a photoreceptor involved in detecting red to far-red light ratio associated with plant density, can increase tuber yield in field-grown transgenic potato (Solanum tuberosum) crops. Surprisingly, this effect was larger at very high densities, despite the intense reduction in the red to far-red light ratios and the concomitant narrowed differences in active phytochrome B levels between wild type and transgenics at these densities. Increased PHYB expression not only altered the ability of plants to respond to light signals, but they also modified the light environment itself. This combination resulted in larger effects of enhanced PHYB expression on tuber number and crop photosynthesis at high planting densities. The PHYB transgenics showed higher maximum photosynthesis in leaves of all strata of the canopy, and this effect was largely due to increased leaf stomatal conductance. We propose that enhanced PHYB expression could be used in breeding programs to shift optimum planting densities to higher levels. PMID:14605224

  7. From rainfed agriculture to stress-avoidance irrigation: II. Sustainability, crop yield, and profitability

    NASA Astrophysics Data System (ADS)

    Vico, Giulia; Porporato, Amilcare

    2011-02-01

    The optimality of irrigation strategies may be sought with respect to a number of criteria, including water requirements, crop yield, and profitability. To explore the suitability of different demand-based irrigation strategies, we link the probabilistic description of irrigation requirements under stochastic hydro-climatic conditions, provided in a companion paper [Vico G, Porporato A. From rainfed agriculture to stress-avoidance irrigation: I. A generalized irrigation scheme with stochastic soil moisture. Adv Water Resour 2011;34(2):263-71], to crop-yield and economic analyses. Water requirements, application efficiency, and investment costs of different irrigation methods, such as surface, sprinkler and drip irrigation systems, are described via a unified conceptual and theoretical approach, which includes rainfed agriculture and stress-avoidance irrigation as extreme cases. This allows us to analyze irrigation strategies with respect to sustainability, productivity, and economic return, using the same framework, and quantify them as a function of climate, crop, and soil parameters. We apply our results to corn ( Zea mays), a food staple and biofuel source, which is currently mainly irrigated through surface systems. As our analysis shows, micro-irrigation maximizes water productivity, but more traditional solutions may be more profitable at least in some contexts.

  8. Determination of potential management zones from soil electrical conductivity, yield and crop data.

    PubMed

    Li, Yan; Shi, Zhou; Wu, Ci-fang; Li, Hong-yi; Li, Feng

    2008-01-01

    One approach to apply precision agriculture to optimize crop production and environmental quality is identifying management zones. In this paper, the variables of soil electrical conductivity (EC) data, cotton yield data and normalized difference vegetation index (NDVI) data in an about 15 ha field in a coastal saline land were selected as data resources, and their spatial variabilities were firstly analyzed and spatial distribution maps constructed with geostatistics technique. Then fuzzy c-means clustering algorithm was used to define management zones, fuzzy performance index (FPI) and normalized classification entropy (NCE) were used to determine the optimal cluster numbers. Finally one-way variance analysis was performed on 224 georeferenced soil and yield sampling points to assess how well the defined management zones reflected the soil properties and productivity level. The results reveal that the optimal number of management zones for the present study area was 3 and the defined management zones provided a better description of soil properties and yield variation. Statistical analyses indicate significant differences between the chemical properties of soil samples and crop yield in each management zone, and management zone 3 presented the highest nutrient level and potential crop productivity, whereas management zone 1 the lowest. Based on these findings, we conclude that fuzzy c-means clustering approach can be used to delineate management zones by using the given three variables in the coastal saline soils, and the defined management zones form an objective basis for targeting soil samples for nutrient analysis and development of site-specific application strategies. PMID:18196615

  9. Towards probabilistic projections of climate change impacts on global crop yields

    NASA Astrophysics Data System (ADS)

    Tebaldi, C.; Lobell, D. B.

    2008-04-01

    There is a widely recognized need in the scientific and policy communities for probabilistic estimates of climate change impacts, beyond simple scenario analysis. Here we propose a methodology to evaluate one major climate change impact - changes in global average yields of wheat, maize, and barley by 2030 - by a probabilistic approach that integrates uncertainties in climate change and crop yield responses to temperature, precipitation, and carbon dioxide. The resulting probability distributions, which are conditional on assuming the SRES A1B emission scenario and no agricultural adaptation, indicate expected changes of +1.6%, -14.1%, -1.8% for wheat, maize, and barley, with 95% probability intervals of (-4.1, +6.7), (-28.0, -4.3), (-11.0, 6.2) in percent of current yields, respectively. This fully probabilistic analysis aims at quantifying the range of plausible outcomes and allows us to gauge the relative importance of different sources of uncertainty.

  10. Economic impacts of policies affecting crop biotechnology and trade.

    PubMed

    Anderson, Kym

    2010-11-30

    Agricultural biotechnologies, and especially transgenic crops, have the potential to boost food security in developing countries by offering higher incomes for farmers and lower priced and better quality food for consumers. That potential is being heavily compromised, however, because the European Union and some other countries have implemented strict regulatory systems to govern their production and consumption of genetically modified (GM) food and feed crops, and to prevent imports of foods and feedstuffs that do not meet these strict standards. This paper analyses empirically the potential economic effects of adopting transgenic crops in Asia and Sub-Saharan Africa. It does so using a multi-country, multi-product model of the global economy. The results suggest the economic welfare gains from crop biotechnology adoption are potentially very large, and that those benefits are diminished only very slightly by the presence of the European Union's restriction on imports of GM foods. That is, if developing countries retain bans on GM crop production in an attempt to maintain access to EU markets for non-GM products, the loss to their food consumers as well as to farmers in those developing countries is huge relative to the slight loss that could be incurred from not retaining EU market access. PMID:20478422

  11. Fertilizer source and tillage effects on yield-scaled nitrous oxide emissions in a corn cropping system.

    PubMed

    Venterea, Rodney T; Bijesh, Maharjan; Dolan, Michael S

    2011-01-01

    Management practices such as fertilizer or tillage regime may affect nitrous oxide (N₂O) emissions and crop yields, each of which is commonly expressed with respect to area (e.g., kg N ha or Mg grain ha). Expressing N₂O emissions per unit of yield can account for both of these management impacts and might provide a useful metric for greenhouse gas inventories by relating N₂O emissions to grain production rates. The objective of this study was to examine the effects of long-term (>17 yr) tillage treatments and N fertilizer source on area- and yield-scaled N₂O emissions, soil N intensity, and nitrogen use efficiency for rainfed corn ( L.) in Minnesota over three growing seasons. Two different controlled-release fertilizers (CRFs) and conventional urea (CU) were surface-applied at 146 kg N ha(-1) several weeks after planting to conventional tillage (CT) and no-till (NT) treatments. Yield-scaled emissions across all treatments represented 0.4 to 1.1% of the N harvested in the grain. Both CRFs reduced soil nitrate intensity, but not N₂O emissions, compared with CU. One CRF, consisting of nitrification and urease inhibitors added to urea, decreased N₂O emissions compared with a polymer-coated urea (PCU). The PCU tended to have lower yields during the drier years of the study, which increased its yield-scaled N₂O emissions. The overall effectiveness of CRFs compared with CU in this study may have been reduced because they were applied several weeks after corn was planted. Across all N treatments, area-scaled N₂O emissions were not significantly affected by tillage. However, when expressed per unit yield of grain, grain N, or total aboveground N, N₂O emissions with NT were 52, 66, and 69% greater, respectively, compared with CT. Thus, in this cropping system and climate regime, production of an equivalent amount of grain using NT would generate substantially more N₂O compared with CT. PMID:21869514

  12. Estimates of spatial and temporal variation of energy crops biomass yields in the US

    NASA Astrophysics Data System (ADS)

    Song, Y.; Jain, A. K.; Landuyt, W.; Kheshgi, H. S.

    2013-12-01

    Perennial grasses, such as switchgrass (Panicum viragatum) and Miscanthus (Miscanthus x giganteus) have been identified for potential use as biomass feedstocks in the US. Current research on perennial grass biomass production has been evaluated on small-scale plots. However, the extent to which this potential can be realized at a landscape-scale will depend on the biophysical potential to grow these grasses with minimum possible amount of land that needs to be diverted from food to fuel production. To assess this potential three questions about the biomass yield for these grasses need to be answered: (1) how the yields for different grasses are varied spatially and temporally across the US; (2) whether the yields are temporally stable or not; and (3) how the spatial and temporal trends in yields of these perennial grasses are controlled by limiting factors, including soil type, water availability, climate, and crop varieties. To answer these questions, the growth processes of the perennial grasses are implemented into a coupled biophysical, physiological and biogeochemical model (ISAM). The model has been applied to quantitatively investigate the spatial and temporal trends in biomass yields for over the period 1980 -2010 in the US. The bioenergy grasses considered in this study include Miscanthus, Cave-in-Rock switchgrass and Alamo switchgrass. The effects of climate, soil and topography on the spatial and temporal trends of biomass yields are quantitatively analyzed using principal component analysis and GIS based geographically weighted regression. The spatial temporal trend results are evaluated further to classify each part of the US into four homogeneous potential yield zones: high and stable yield zone (HS), high but unstable yield zone (HU), low and stable yield zone (LS) and low but unstable yield zone (LU). Our preliminary results indicate that the yields for perennial grasses among different zones are strongly related to the different controlling factors

  13. Remotely sensed vegetation indices for seasonal crop yields predictions in the Czech Republic

    NASA Astrophysics Data System (ADS)

    Hlavinka, Petr; Semerádová, Daniela; Balek, Jan; Bohovic, Roman; Žalud, Zdeněk; Trnka, Miroslav

    2015-04-01

    Remotely sensed vegetation indices by satellites are valuable tool for vegetation conditions assessment also in the case of field crops. This study is based on the use of NDVI (Normalized Difference Vegetation Index) and EVI (Enhanced Vegetation Index) derived from MODIS (Moderate Resolution Imaging Spectroradiometer) aboard Terra satellite. Data available from the year 2000 were analyzed and tested for seasonal yields predictions within selected districts of the Czech Republic (Central Europe). Namely the yields of spring barley, winter wheat and oilseed winter rape during the period from 2000 to 2014 were assessed. Observed yields from 14 districts (NUTS 4) were collected and thus 210 seasons were included. Selected districts differ considerably in their soil fertility and terrain configuration and represent transect across various agroclimatic conditions (from warm and dry to relative cool and wet regions). Two approaches were tested: 1) using of composite remotely sensed data (available in 16 day time step) provided by the USGS (https://lpdaac.usgs.gov/); 2) using daily remotely sensed data in combination with originally developed smoothing method. The yields were successfully predicted based on established regression models (remotely sensed data used as independent parameter). Besides others the impact of severe drought episodes within vegetation were identified and yield reductions at district level predicted (even before harvest). As a result the periods with the best relationship between remotely sensed data and yields were identified. The impact of drought conditions as well as normal or above normal yields of field crops could be predicted by proposed method within study region up to 30 days prior to the harvest. It could be concluded that remotely sensed vegetation conditions assessment should be important part of early warning systems focused on drought. Such information should be widely available for various users (decision makers, farmers, etc.) in

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

    PubMed

    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. PMID:26024252

  15. Crop rotations with annual and perennial forages under no-till soil management: soil attributes, soybean mineral nutrition, and yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extensive use of sustainable and intensive agricultural systems would result in profitable farms producing greater yields while maintaining or enhancing natural resources. Development of sustainable crop and soil management systems depends on understanding complex relationships between soil managem...

  16. Assessing the impacts of current and future concentrations of surface ozone on crop yield with meta-analysis

    NASA Astrophysics Data System (ADS)

    Feng, Zhaozhong; Kobayashi, Kazuhiko

    Meta-analysis was conducted to quantitatively assess the effects of rising ozone concentrations ([O 3]) on yield and yield components of major food crops: potato, barley, wheat, rice, bean and soybean in 406 experimental observations. Yield loss of the crops under current and future [O 3] was expressed relative to the yield under base [O 3] (≤26 ppb). With potato, current [O 3] (31-50 ppb) reduced the yield by 5.3%, and it reduced the yield of barley, wheat and rice by 8.9%, 9.7% and 17.5%, respectively. In bean and soybean, the yield losses were 19.0% and 7.7%, respectively. Compared with yield loss at current [O 3], future [O 3] (51-75 ppb) drove a further 10% loss in yield of soybean, wheat and rice, and 20% loss in bean. Mass of individual grain, seed, or tuber was often the major cause of the yield loss at current and future [O 3], whereas other yield components also contributed to the yield loss in some cases. No significant difference was found between the responses in crops grown in pots and those in the ground for any yield parameters. The ameliorating effect of elevated [CO 2] was significant in the yields of wheat and potato, and the individual grain weight in wheat exposed to future [O 3]. These findings confirm the rising [O 3] as a threat to food security for the growing global population in this century.

  17. Evaluating a satellite-based seasonal evapotranspiration product and identifying its relationship with other satellite-derived products and crop yield: A case study for Ethiopia

    NASA Astrophysics Data System (ADS)

    Tadesse, Tsegaye; Senay, Gabriel B.; Berhan, Getachew; Regassa, Teshome; Beyene, Shimelis

    2015-08-01

    Satellite-derived evapotranspiration anomalies and normalized difference vegetation index (NDVI) products from Moderate Resolution Imaging Spectroradiometer (MODIS) data are currently used for African agricultural drought monitoring and food security status assessment. In this study, a process to evaluate satellite-derived evapotranspiration (ETa) products with a geospatial statistical exploratory technique that uses NDVI, satellite-derived rainfall estimate (RFE), and crop yield data has been developed. The main goal of this study was to evaluate the ETa using the NDVI and RFE, and identify a relationship between the ETa and Ethiopia's cereal crop (i.e., teff, sorghum, corn/maize, barley, and wheat) yields during the main rainy season. Since crop production is one of the main factors affecting food security, the evaluation of remote sensing-based seasonal ETa was done to identify the appropriateness of this tool as a proxy for monitoring vegetation condition in drought vulnerable and food insecure areas to support decision makers. The results of this study showed that the comparison between seasonal ETa and RFE produced strong correlation (R2 > 0.99) for all 41 crop growing zones in Ethiopia. The results of the spatial regression analyses of seasonal ETa and NDVI using Ordinary Least Squares and Geographically Weighted Regression showed relatively weak yearly spatial relationships (R2 < 0.7) for all cropping zones. However, for each individual crop zones, the correlation between NDVI and ETa ranged between 0.3 and 0.84 for about 44% of the cropping zones. Similarly, for each individual crop zones, the correlation (R2) between the seasonal ETa anomaly and de-trended cereal crop yield was between 0.4 and 0.82 for 76% (31 out of 41) of the crop growing zones. The preliminary results indicated that the ETa products have a good predictive potential for these 31 identified zones in Ethiopia. Decision makers may potentially use ETa products for monitoring cereal crop

  18. Weed Seedling Emergence and Survival as Affected by Crop Canopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study measured impact of cool-season crops on seedling emergence, survival, and seed production of weeds common in corn and soybean. Weed dynamics were monitored in permanently-marked quadrats in winter wheat, spring wheat, and canola. Three species, green foxtail, yellow foxtail, and common ...

  19. Chemical composition of cottonseed affected by cropping management practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cottonseed is a valuable raw material for a range of food, animal feed, and industrial (such as adhesives) products. Chemical composition is one of the critical parameters to evaluate cottonseed's quality and potential end use. However, the information on the impacts of cropping management practices...

  20. Aminopyralid soil residues affect rotational vegetable crops in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field experiments were conducted to determine the sensitivity of bell pepper, eggplant, tomato, muskmelon, and watermelon to aminopyralid soil residues. Aminopyralid was applied at six rates ranging from 0.0014 kg ae ha 1 to 0.0448 kg ae ha 1, and vegetable crops were planted in the treated areas. ...

  1. COVER CROP SYSTEMS AFFECT WEED COMMUNITIES IN A CALIFORNIA VINEYARD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vineyard weed communities were examined under four dormant season cover crop systems representative of those used in the north-coastal grape-growing region of California: no-till annuals (rose clover, soft brome, zorro fescue; ANoT), no-till perennials (blue wildrye, California brome, meadow barley,...

  2. Can Novel Management Practice Improve Soil and Environmental Quality and Sustain Crop Yield Simultaneously?

    PubMed

    Sainju, Upendra M

    2016-01-01

    Little is known about management practices that can simultaneously improve soil and environmental quality and sustain crop yields. The effects of novel and traditional management practices that included a combination of tillage, crop rotation, and N fertilization on soil C and N, global warming potential (GWP), greenhouse gas intensity (GHGI), and malt barley (Hordeum vulgarie L.) yield and quality were examined under non-irrigated and irrigated cropping systems from 2008 to 2011 in eastern Montana and western North Dakota, USA. In loamy soil under non-irrigated condition in eastern Montana, novel and traditional management practices were no-till malt barley-pea (Pisum sativum L.) with 80 kg N ha(-1) and conventional till malt barley-fallow with 80 kg N ha(-1), respectively. In sandy loam soil under irrigated and non-irrigated conditions in western North Dakota, novel and traditional management practices included no-till malt barley-pea with 67 (non-irrigated) to 134 kg N ha(-1) (irrigated) and conventional till malt barley with 67 (non-irrigated) to 134 kg N ha(-1) (irrigated), respectively. Compared with the traditional management practice, soil organic C (SOC) and total N (STN) at 0-120 cm were 5% greater with the novel management practice under non-irrigated condition in eastern Montana and under irrigated condition in western North Dakota, but were not different under non-irrigated condition in western North Dakota. In both places under irrigated and non-irrigated conditions, total applied N rate, residual soil NO3-N content at 0-120 cm, global warming potential (GWP), and greenhouse gas intensity (GHGI) were 15 to 70% lower with the novel than the traditional management practice. Malt barley yield and quality were not different between the two practices in both places. Novel management practices, such as no-till malt barley-pea with reduced N rate, can simultaneously enhance soil and environmental quality, reduce N input, and sustain crop yield compared with

  3. Can Novel Management Practice Improve Soil and Environmental Quality and Sustain Crop Yield Simultaneously?

    PubMed Central

    Sainju, Upendra M.

    2016-01-01

    Little is known about management practices that can simultaneously improve soil and environmental quality and sustain crop yields. The effects of novel and traditional management practices that included a combination of tillage, crop rotation, and N fertilization on soil C and N, global warming potential (GWP), greenhouse gas intensity (GHGI), and malt barley (Hordeum vulgarie L.) yield and quality were examined under non-irrigated and irrigated cropping systems from 2008 to 2011 in eastern Montana and western North Dakota, USA. In loamy soil under non-irrigated condition in eastern Montana, novel and traditional management practices were no-till malt barley-pea (Pisum sativum L.) with 80 kg N ha-1 and conventional till malt barley-fallow with 80 kg N ha-1, respectively. In sandy loam soil under irrigated and non-irrigated conditions in western North Dakota, novel and traditional management practices included no-till malt barley-pea with 67 (non-irrigated) to 134 kg N ha-1 (irrigated) and conventional till malt barley with 67 (non-irrigated) to 134 kg N ha-1 (irrigated), respectively. Compared with the traditional management practice, soil organic C (SOC) and total N (STN) at 0–120 cm were 5% greater with the novel management practice under non-irrigated condition in eastern Montana and under irrigated condition in western North Dakota, but were not different under non-irrigated condition in western North Dakota. In both places under irrigated and non-irrigated conditions, total applied N rate, residual soil NO3-N content at 0–120 cm, global warming potential (GWP), and greenhouse gas intensity (GHGI) were 15 to 70% lower with the novel than the traditional management practice. Malt barley yield and quality were not different between the two practices in both places. Novel management practices, such as no-till malt barley-pea with reduced N rate, can simultaneously enhance soil and environmental quality, reduce N input, and sustain crop yield compared with

  4. Effect of plant density and mixing ratio on crop yield in sweet corn/mungbean intercropping.

    PubMed

    Sarlak, S; Aghaalikhani, M; Zand, B

    2008-09-01

    In order to evaluate the ear and forage yield of sweet corn (Zea mays L. var. Saccarata) in pure stand and intercropped with mung bean (Vigna radiata L.), a field experiment was conducted at Varamin region on summer 2006. Experiment was carried out in a split plot design based on randomized complete blocks with 4 replications. Plant density with 3 levels [Low (D1), Mean (D2) and High (D3) respecting 6, 8 and 10 m(-2) for sweet corn, cultivar S.C.403 and 10, 20 and 30 m(-2) for mung bean cultivar, Partow] was arranged in main plots and 5 mixing ratios [(P1) = 0/100, (P2) = 25/75, (P3) = 50/50, (P4) = 75/25, (P5) = 100/0% for sweet corn/mung bean, respectively] were arranged in subplots. Quantitative attributes such as plant height, sucker numbers, LER, dry matter distribution in different plant organs were measured in sweet corn economical maturity. Furthermore the yield of cannable ear corn and yield components of sweet corn and mung bean were investigated. Results showed that plant density has not any significant effect on evaluated traits, while the effect of mixing ratio was significant (p < 0.01). Therefore, the mixing ratio of 75/25 (sweet corn/mung bean) could be introduced as the superior mixing ratio; because of it's maximum rate of total sweet corn's biomass, forage yield, yield and yield components of ear corn in intercropping. Regarding to profitability indices of intercropping, the mixing ratio 75/25 (sweet corn/mung bean) in low density (D1P2) which showed the LER = 1.03 and 1.09 for total crop yield before ear harvesting and total forage yield after ear harvest respectively, was better than corn or mung bean monoculture. PMID:19266927

  5. Assessing crop-specific impacts of extremely wet (2007) and dry (2003) conditions in France on regional maize and wheat yields

    NASA Astrophysics Data System (ADS)

    van der Velde, Marijn

    2010-05-01

    Extreme weather conditions can strongly affect agricultural production. In France, crop yields were greatly influenced by drought and heat stress in 2003 and by extremely wet conditions in 2007. Both maize and wheat yield where historically low in 2003, in contrast to 2007 when wheat yields were lower and maize yields were higher than long-term averages. Even though maize yield loss was lower in regions with higher maize irrigation percentages; yield loss was still very considerable. Remotely sensed (AMSR-E) JJA soil moisture related significantly to reported regional crop yield for 2002-2007. The spatial correlation between JJA soil moisture and wheat yield anomalies was positive in dry 2003 and negative in wet 2007. Biweekly soil moisture correlated positively from the first half of June until the second half of July in 2003. In 2007, the relation was negative the first half of June until the second half of August. An analysis with a spatial version (10 by 10 km) of the EPIC crop growth model was used to infer causal relations between rainfall, soil moisture and rainfed wheat and rainfed and irrigated maize yield. The negative impacts of the 2003 heat wave and drought on wheat yield were captured by the model, while negative damages to yield due to excessive wetness in 2007 were not. Modelling suggests that regional drought mitigation increased with increasing maize irrigation percentages from 0 to 40%. At higher irrigation percentages the compensating effect of irrigation was small. The above average maize yields in 2007 were reproduced by the model, but the below average wheat yields were not. The model overestimation of wheat yield in 2007 may be due to a misrepresentation of the impact of wet conditions on plant physiological processes, or due to the incapacity of the model to represent determining factors such as lodging and unfavourable harvesting conditions. Strenghts and limitations of this regional assessment will be discussed. Extreme events affect

  6. Crop weather models of barley and spring wheat yield for agrophysical units in North Dakota

    NASA Technical Reports Server (NTRS)

    Leduc, S. (Principal Investigator)

    1982-01-01

    Models based on multiple regression were developed to estimate barley yield and spring wheat yield from weather data for Agrophysical units(APU) in North Dakota. The predictor variables are derived from monthly average temperature and monthly total precipitation data at meteorological stations in the cooperative network. The models are similar in form to the previous models developed for Crop Reporting Districts (CRD). The trends and derived variables were the same and the approach to select the significant predictors was similar to that used in developing the CRD models. The APU models show sight improvements in some of the statistics of the models, e.g., explained variation. These models are to be independently evaluated and compared to the previously evaluated CRD models. The comparison will indicate the preferred model area for this application, i.e., APU or CRD.

  7. Assimilation of MODIS-derived LAI by radiative transfer modelling to crop growth simulation model for rice crop monitoring and yield estimation in the Mekong delta, Vietnam

    NASA Astrophysics Data System (ADS)

    Nguyen, H.; de Bie, K.; Verhoef, W.

    2014-12-01

    Successful monitoring of rice crops and estimation of its yields in Mekong delta provide vital information to government agencies, rice production stakeholders and insurance companies in making their decisions and plans to establish solutions to protect rice smallholders from the risks involved. Remote sensing-based information promises a cost-effective way to observe rice crop growth in the largest rice producing region of Vietnam. For an extensive rice cultivation region as the Mekong delta, the use of divergence statistic to extract information from long-term or hypertemporal optical remote sensing NDVI profile to map rice cropping patterns has shown a high degree of success. The result map provides accurate information on where rice grew, when it was seeded and harvested, how many time it was cultivated every year. In addition, by using 8-day MODIS TERRA surface reflectance in Soil-Leaf-Canopy (SLC) radiative transfer model, 70 percent variation of seasonal rice LAI values was able to capture, making it useful to be assimilated into a rice crop growth simulation model (ORYZA 2000) to estimate the regional rice production in the season of 2008-2009. Tested results from 56 rice fields located in different rice cropping patterns showed that yields estimated using ORYZA2000 can explain 83 percent variation of field measured yields. However, simulated yields by ORYZA 2000 were used to overestimate by the model since some of model parameters could not be recalibrated due to the lack of field experiment data. This suggest that in the future, in order to gain a better results of rice crop monitoring and yield estimation, apart from improving the estimation of MODIS -derived LAIs by using SLC, calibrating crop growth simulation's parameter have to be taken into account.

  8. Past and future climate patterns affecting temperate, sub-tropical and tropical horticultural crop production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial horticultural crop production will be impacted by climate change effects on temperature, water availability, solar radiation, air pollution, and carbon dioxide. Horticultural crop value is derived from both the quantity and the quality of the harvested product; both of which are affected ...

  9. Can deficit irrigation techniques be used to enhance phosphorus and water use efficiency and benefit crop yields?

    NASA Astrophysics Data System (ADS)

    Wright, Hannah R.; Dodd, Ian C.; Blackwell, Martin S. A.; Surridge, Ben W. J.

    2015-04-01

    Soil drying and rewetting (DRW) affects the forms and availability of phosphorus (P). Water soluble P has been reported to increase 1.8- to 19-fold after air-drying with the majority of the increase (56-100%) attributable to organic P. Similarly, in two contrasting soil types DRW increased concentrations of total P and reactive P in leachate, likely due to enhanced P mineralisation and physiochemical processes causing detachment of soil colloids, with faster rewetting rates related to higher concentrations of P. The intensity of drying as well as the rate of rewetting influences organic and inorganic P cycling. How these dynamics are driven by soil water status, and impact crop P acquisition and growth, remains unclear. Improving P and water use efficiencies and crop yields is globally important as both P and water resources become increasingly scarce, whilst demand for food increases. Irrigation supply below the water requirement for full crop evapotranspiration is employed by agricultural practitioners where water supply is limited. Regulated deficit irrigation describes the scheduling of water supply to correspond to the times of highest crop demand. Alternate wetting and drying (AWD) is applied in lowland irrigated rice production to avoid flooding at certain times of crop development, and has benefited P nutrition and yields. This research aims to optimise the benefits of P availability and uptake achieved by DRW by guiding deficit irrigation management strategies. Further determination of underlying processes driving P cycling at fluctuating soil moisture status is required. Presented here is a summary of the literature on DRW effects on soil P availability and plant P uptake and partitioning, in a range of soil types and cropping systems, with emphasis on alternate wetting and drying irrigation (AWD) compared to continuous flooding in lowland irrigated rice production. Soil water contents and matric potentials, and effects on P dynamics, are highly variable

  10. Crop yield and light / energy efficiency in a closed ecological system: two laboratory biosphere experiments

    NASA Astrophysics Data System (ADS)

    Nelson, M.; Dempster, W. F.; Silverstone, S.; Alling, A.; Allen, J. P.; van Thillo, M.

    Two crop growth experiments in the soil-based closed ecological facity, Laboratory Biosphere, were conducted from 2003-2004 with candidate space life support crops. Apogee wheat (Utah State University variety) was grown, planted in 2 densities, 400 and 800 seeds m-2. The lighting regime for the wheat crop was 16 hours of light -- 8 hours dark at a total light intensity of around 840 mol m2 sec-1 and 48.4 mol m-2 d-1 over 84 days Average biomass was 1395 g m-2, 16.0 g m-2 day-1 and average seed production was 689 g m-2 and 7.9 g m2 day-1. The less densely planted side was more productive than the denser planting, with 1634 g m-2 and 18.8g m-2 day-1 of biomass vs. 1156 g m-2 and 13.3 g m-2 day-1; and a seed harvest of 812.3 g m-2 and 9.3 g m-2 day-1 vs. 566.5 g m-2 and 6.5 g m-2 day-1 Harvest index was 0.49 for the wheat crop. The experiment with sweet potato used TU-82-155, a compact variety developed at Tuskegee University. Light during the sweet potato experiment, on a 16 hour on/8 hours dark cycle, totalled 5568 total moles of light in 126 days for the sweet potatoes, or an average of 44.2 moles m-2 day-1. Temperature regime was 28 deg +/- 3 deg C day /22 deg +/- 4 deg C night. Sweet potato tuber yield was 39.7 kg wet weight, or an average of 7.4 kg m-2 and 7.7 kg dry weight of tubers since dry weight was about 18.6% wet weight.^Average per day production was 58.7 g m-2 day-1 wet weight and 11.3 g m-2 day-1. For the wheat, average light efficiency was 0.34 grams biomass per mole, and 0.17 grams seed per mole. The best area of wheat had an efficiency of light utilization of 0.51 g biomass per mole and 0.22 g seed per mole. For the sweet potato crop, light efficiency per tuber wet weight was 7.13 g/mole and 1.38 g dry weight of tuber per mole of light. The best area of tuber production had 9.49 g/mole wet weight and 1.85 g/mole of light dry weight. Production from the wheat was The Laboratory Biosphere experiment's light efficiency was somewhat higher than the USU

  11. Using Canopy Reflectance and Crop Stress Index to Enhance Wheat Yield Prediction

    NASA Astrophysics Data System (ADS)

    Asadi, S.; Zare, H.; Paymard, P.; Lashkari, A.; Salehnia, N.; Bannayan, M.

    2015-12-01

    Canopy reflectance can be useful indicator of crop health status. Canopy stress index (CSI) is usually expressed as canopy temperature minus air temperature, and this value is higher and a positive number in a well irrigated wheat field. Three main environmental variables constructing CSI are: plant canopy temperature (Tc), air temperature (Ta) and atmospheric vapor pressure deficiency (VPD). CSI is effected by biological and environmental factors such as soil water status, wind speed, evapotranspiration, conduction systems, plant metabolism, air temperature, relative humidity, etc. which all influence on final yield. This paper aims to investigate the relation of CSI calculated by Landsat images and wheat yield. So, eighteen wheat fields were selected for two years (2009 and 2010) and 5 Landsat images (TM and ETM+) from April to Jun were used to monitor field status in each year. Tc was calculated by applying single-channel method and VPD was computed from Tc, air temperature and humidity. Each single Landsat bands and CSI were defined as the descriptor variables. Relation between wheat yield and the descriptors was assessed by means of linear correlation. The results of stepwise correlation depicted that band 1 (blue) and 3 (red) had the most correlations to yield until grain filling stage. This reflects the importance of photosynthesis rate which absorb blue and red wavelength during mentioned period. This two bands also could capture yield changes (r2=0.77). However, during grain filling period CSI was the only descriptor determining yield volatility (r2=0.85). Low temperature is one of the key factors which increase remobilization of carbohydrate to grain. Therefore, grain yield in the canopy which has less temperature in compared to air temperature would be higher than others.

  12. Trends in Crop Management and Phenology in the U.S. Corn Belt, and Effects on Yields, Evapotranspiration and Energy Balance

    NASA Astrophysics Data System (ADS)

    Sacks, W. J.; Kucharik, C. J.

    2010-12-01

    Two important factors that can affect crop yields are planting dates and the length of the crop growth period. We analyzed 25 years of data collected by the USDA in order to document trends in planting dates, lengths of the vegetative and reproductive growth periods, and the length of time between maturity and harvest for corn and soybeans across the U.S. We then used these observations to drive the Agro-IBIS model, in order to investigate the effects of changing planting dates and crop cultivars on crop yields and fluxes of water and energy. Averaged across the U.S., corn planting dates advanced about 10 days from 1981 to 2005, and soybean planting dates about 12 days. For both crops, but especially for corn, this has been accompanied by a lengthening of the growth period. The period from corn planting to maturity was about 12 days longer around 2005 than it was around 1981. A large driver of this change was a 14% increase in the number of growing degree days needed for corn to progress through the grainfill period, probably reflecting an adoption of longer-season cultivars. This trend to longer-season cultivars was responsible for a 12.6 bu ac-1 yield increase across the U.S. Corn Belt over this 25-year period, according to our simulations. Thus, the adoption of longer-season cultivars can account for 26% of the observed yield trend. These changes in crop phenology, together with a shortening of the time from maturity to harvest, have also modified the surface water and energy balance. Earlier planting has led to an increase in the latent heat flux and a decrease in the sensible heat flux in June, while a shorter time from maturity to harvest has meant an increase in net radiation in October.

  13. The impact of large-scale circulation patterns on summer crop yields in IP

    NASA Astrophysics Data System (ADS)

    Capa Morocho, Mirian; Rodríguez Fonseca, Belén; Ruiz Ramos, Margarita

    2014-05-01

    Large-scale circulations patterns (ENSO, NAO) have been shown to have a significant impact on seasonal weather, and therefore on crop yield over many parts of the world(Garnett and Khandekar, 1992; Aasa et al., 2004; Rozas and Garcia-Gonzalez, 2012). In this study, we analyze the influence of large-scale circulation patterns and regional climate on the principal components of maize yield variability in Iberian Peninsula (IP) using reanalysis datasets. Additionally, we investigate the modulation of these relationships by multidecadal patterns. This study is performed analyzing long time series of maize yield, only climate dependent, computed with the crop model CERES-maize (Jones and Kiniry, 1986) included in Decision Support System for Agrotechnology Transfer (DSSAT v.4.5). To simulate yields, reanalysis daily data of radiation, maximum and minimum temperature and precipitation were used. The reanalysis climate data were obtained from National Center for Environmental Prediction (20th Century and NCEP) and European Centre for Medium-Range Weather Forecasts (ECMWF) data server (ERA 40 and ERA Interim). Simulations were run at five locations: Lugo (northwestern), Lerida (NE), Madrid (central), Albacete (southeastern) and Córdoba (S IP) (Gabaldón et al., 2013). From these time series standardized anomalies were calculated. Afterwards, time series were time filtered to focus on the interannual-to-multiannual variability, splitting up in two components: low frequency (LF) and high frequency (HF) time scales. The principal components of HF yield anomalies in IP were compared with a set of documented patterns. These relationships were compared with multidecadal patterns, as Atlanctic Multidecadal Oscillations (AMO) and Interdecadal Pacific Oscillations (IPO). The results of this study have important implications in crop forecasting. In this way, it may have a positive impact on both public (agricultural planning) and private (decision support to farmers, insurance

  14. Impact of land management system on crop yields and soil fertility in Cameroon

    NASA Astrophysics Data System (ADS)

    Tsozué, D.; Nghonda, J. P.; Mekem, D. L.

    2015-09-01

    The impact of direct-seeding mulch-based cropping systems (DMC), direct seeding (DS) and tillage seeding (TS) on Sorghum yields, soil fertility and the rehabilitation of degraded soils was evaluated in northern Cameroon. Field work consisted of visual examination, soil sampling, yield and rainfall data collection. Three fertilization rates (F1: 100 kg ha-1 NPK + 25 kg ha-1 of urea in DMC, F2: 200 kg ha-1 NPK + 50 kg ha-1 of urea in DMC and F3: 300 kg ha-1 NPK + 100 kg ha-1 of urea in DMC) were applied to each cropping system (DS, TS and DMC), resulting in nine experimental plots. Two types of chemical fertilizer were used (NPK 22.10.15 and urea) and applied each year from 2002 to 2012. Average Sorghum yields were 1239, 863 and 960 kg ha-1 in DMC, DS and TS, respectively, at F1, 1658, 1139 and 1192 kg ha-1 in DMC, DS and TS, respectively, at F2, and 2270, 2138 and 1780 kg ha-1 in DMC, DS and TS, respectively, at F3. pH values were 5.2-5.7 under DMC, 4.9-5.3 under DS and TS and 5.6 in the control sample. High values of cation exchange capacity were recorded in the control sample, TS system and F1 of DMC. Base saturation rates, total nitrogen and organic matter contents were higher in the control sample and DMC than in the other systems. All studied soils were permanently not suitable for Sorghum due to the high percentage of nodules. F1 and F2 of the DS were currently not suitable, while F1 and F3 of DMC, F3 of DS and F1, F2 and F3 of TS were marginally suitable for Sorghum due to low pH values.

  15. Impact of land management system on crop yields and soil fertility in Cameroon

    NASA Astrophysics Data System (ADS)

    Tsozué, D.; Nghonda, J. P.; Mekem, D. L.

    2015-06-01

    The impact of direct-seeding mulch-based cropping systems (DMC), direct seeding (DS) and tillage seeding (TS) on Sorghum yields, soil fertility and the rehabilitation of degraded soils was evaluated in northern Cameroon. Field work consisted of visual examination, soil sampling, yield and rainfall data collection. Three fertilization rates (F1: 100 kg ha-1 NPK + 25 kg ha-1 of urea in DMC, F2: 200 kg ha-1 NPK + 50 kg ha-1 of urea in DMC and F3: 300 kg ha-1 NPK + 100 kg ha-1 of urea in DMC) were applied to each cropping system (DS, TS and DMC), resulting in nine experimental plots. Two types of chemical fertilizer were used (NPK 22.10.15 and urea) and applied each year from 2002 to 2012. Average Sorghum yields were 1239, 863 and 960 kg ha-1 respectively in DMC, DS and TS at F1, 1658, 1139 and 1192 kg ha-1 respectively in DMC, DS and TS at F2, and 2270, 2138 and 1780 kg ha-1 respectively in DMC, DS and TS at F3. pH values were 5.2 to 5.7 under DMC, 4.9 to 5.3 under DS and TS, and 5.6 in the control sample. High values of cation exchange capacity were recorded in the control sample, TS system and F1 of DMC. Base saturation rates, total nitrogen and organic matter contents were high in the control sample and the DMC than in the others systems. All studied soils were permanently not suitable for Sorghum due to the high percentage of nodules. F1 and F2 of the DS were currently not suitable, while F1 and F3 of DMC, F3 of DS and F1, F2 and F3 of TS were marginally suitable for Sorghum due to low soil pH values.

  16. Improving potato cropping systems: longer-term effects on diseases and yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of effective cropping systems can provide the structural basis for enhanced crop production and sustainability through the conservation, maintenance, and replenishment of various soil resources. In 2004, field trials evaluating potato cropping systems focused on different specific cr...

  17. Cover Crop Biomass and Corn Yield Following 13 Rye, Wheat, and Triticale Cultivars Used as Winter Cover Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter cover crops have the potential to reduce nitrate leaching and erosion in corn-soybean rotations in the upper Midwest. The cover crop growing season between harvest and planting of corn and soybean, however, is short and cold. Additionally, previous studies in Iowa have indicated that winter r...

  18. Tillage and grazing impact on annual crop yields following a conversion from perennial grass to annual crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interest in methods to transition from perennial grasses to annual crops should continue to increase because of expiration of Conservation Reserve Program (CRP) contracts in the USA and a desire by some to include a perennial phase in annual crop rotations. A four-year study was initiated in 2005 at...

  19. Effects of broiler litter rate, timing and cover crop on cotton yield and residual soil N

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Timing of broiler litter applications has critical effect on the availability of litter-derived nutrients and should affect cotton (Gossypium spp.) growth and yield. This experiment was conducted on a Leeper silty clay loam (fine, montmorillionitic, nonacid, thermic Vertic Haplaquepts) soil at Missi...

  20. Soil organic carbon dynamics and crop yield for different crop rotations in a degraded ferruginous tropical soil in a semi-arid region: a simulation approach

    PubMed Central

    SOLER, C. M. TOJO; BADO, V. B.; TRAORE, K.; BOSTICK, W. MCNAIR; JONES, J. W.; HOOGENBOOM, G.

    2011-01-01

    SUMMARY In recent years, simulation models have been used as a complementary tool for research and for quantifying soil carbon sequestration under widely varying conditions. This has improved the understanding and prediction of soil organic carbon (SOC) dynamics and crop yield responses to soil and climate conditions and crop management scenarios. The goal of the present study was to estimate the changes in SOC for different cropping systems in West Africa using a simulation model. A crop rotation experiment conducted in Farakô-Ba, Burkina Faso was used to evaluate the performance of the cropping system model (CSM) of the Decision Support System for Agrotechnology Transfer (DSSAT) for simulating yield of different crops. Eight crop rotations that included cotton, sorghum, peanut, maize and fallow, and three different management scenarios, one without N (control), one with chemical fertilizer (N) and one with manure applications, were studied. The CSM was able to simulate the yield trends of various crops, with inconsistencies for a few years. The simulated SOC increased slightly across the years for the sorghum–fallow rotation with manure application. However, SOC decreased for all other rotations except for the continuous fallow (native grassland), in which the SOC remained stable. The model simulated SOC for the continuous fallow system with a high degree of accuracy normalized root mean square error (RMSE)=0·001, while for the other crop rotations the simulated SOC values were generally within the standard deviation (s.d.) range of the observed data. The crop rotations that included a supplemental N-fertilizer or manure application showed an increase in the average simulated aboveground biomass for all crops. The incorporation of this biomass into the soil after harvest reduced the loss of SOC. In the present study, the observed SOC data were used for characterization of production systems with different SOC dynamics. Following careful evaluation of the CSM

  1. Soil organic carbon dynamics and crop yield for different crop rotations in a degraded ferruginous tropical soil in a semi-arid region: a simulation approach.

    PubMed

    Soler, C M Tojo; Bado, V B; Traore, K; Bostick, W McNair; Jones, J W; Hoogenboom, G

    2011-10-01

    In recent years, simulation models have been used as a complementary tool for research and for quantifying soil carbon sequestration under widely varying conditions. This has improved the understanding and prediction of soil organic carbon (SOC) dynamics and crop yield responses to soil and climate conditions and crop management scenarios. The goal of the present study was to estimate the changes in SOC for different cropping systems in West Africa using a simulation model. A crop rotation experiment conducted in Farakô-Ba, Burkina Faso was used to evaluate the performance of the cropping system model (CSM) of the Decision Support System for Agrotechnology Transfer (DSSAT) for simulating yield of different crops. Eight crop rotations that included cotton, sorghum, peanut, maize and fallow, and three different management scenarios, one without N (control), one with chemical fertilizer (N) and one with manure applications, were studied. The CSM was able to simulate the yield trends of various crops, with inconsistencies for a few years. The simulated SOC increased slightly across the years for the sorghum-fallow rotation with manure application. However, SOC decreased for all other rotations except for the continuous fallow (native grassland), in which the SOC remained stable. The model simulated SOC for the continuous fallow system with a high degree of accuracy normalized root mean square error (RMSE)=0·001, while for the other crop rotations the simulated SOC values were generally within the standard deviation (s.d.) range of the observed data. The crop rotations that included a supplemental N-fertilizer or manure application showed an increase in the average simulated aboveground biomass for all crops. The incorporation of this biomass into the soil after harvest reduced the loss of SOC. In the present study, the observed SOC data were used for characterization of production systems with different SOC dynamics. Following careful evaluation of the CSM with

  2. Vegetation dynamics using AVHRR/NDVI: Regional climate, carbon dioxide fertilization and crop yield relations

    NASA Astrophysics Data System (ADS)

    Lim, Chai Kyung

    Vegetation Anomaly Index (VAI), which is not influenced by vegetation type and is almost perfectly correlated with spatially averaged NDVI over any eco-region. Finally, we examined a possibility of utilizing NDVI to forecast crop yield and crop market price. We found that National Agricultural Statistics Service (MASS) corn yield estimate for Iowa and August NDVI averaged over the selected counties of Iowa are fairly well correlated for the past two decades. The Iowa corn market price is better correlated with NASS yield estimate than the average August NDVI over the counties; however, the correlation is more stable with NDVI than the NASS estimates, which indicates a great possibility of utilizing NDVI to forecast crop related access by USDA.

  3. Climatic Droughts and the Impacts on Crop Yields in Northern India during the Past Century

    NASA Astrophysics Data System (ADS)

    Ge, Y.; Cai, X.; Zhu, T.

    2014-12-01

    Drought has become an increasingly severe threat to water and food security recently. This study presents a novel method to calculate the return period of drought, considering drought as event characterized by expected drought inter-arrival time, duration, severity and peak intensity. Recently, Copula distribution, a multivariable probability distribution, is used to deal with strongly correlated variables in analyzing complex hydrologic phenomenon. This study assesses drought conditions in Northern India, including 8 sites, in the past century using Palmer Drought Severity Index (PDSI) from two latest datasets, Dai (2011, 2013) and Sheffield et al. (2012), which concluded conflicting results about global average drought trend. Our results include the change of the severity, intensity and duration of drought events during the past century and the impact of the drought condition on crop yields in the region. It is found that drought variables are highly correlated, thus copulas joint distribution enables the estimation of multi-variate return period. Based on Dai's dataset from 1900 to 2012, for a fixed drought return period the severity and duration is lower for the period before1955 in sites close to the Indus basin (site 1) or off the coast of the Indian Ocean (Bay of Bengal) (site 8), while they are higher for the period after 1955 in other inland sites (sites 3-7), (e.g., severity in Fig.1). Projections based on two models (IPCC AR4 and AR5) in Dai (2011, 2013) suggested less severity and shorter duration in longer-year drought (e.g., 100-year drought), but larger in shorter-year drought (e.g., 2-year drought). Drought could bring nonlinear responses and unexpected losses in agriculture system, thus prediction and management are essential. Therefore, in the years with extreme drought conditions, impact assessment of drought on crop yield of corn, barley, wheat and sorghum will be also conducted through correlating crop yields with drought conditions during

  4. Manure placement depth impacts on crop yields and N retained in soil.

    PubMed

    Reiman, M; Clay, D E; Carlson, C G; Clay, S A; Reicks, G; Clay, D W; Humburg, D E

    2009-01-01

    The objective of this study was to determine the impact of manure placement depth on crop yield and N retention in soil. Experimental treatments were deep manure injection (45 cm), shallow manure injection (15 cm), and conventional fertilizer-based management with at least three replications per site. Water infiltration, and changes in soil N and P amounts were measured for up to 30 months and crop yield monitored for three seasons following initial treatment. Deep and shallow manure injections differed in soil inorganic N distributions. For example, in the manure slot the spring following application, NO(3)-N in the surface 60 cm was higher (p < .01) when injected 15 cm (21.4 micro g/g) into the soil than 45 cm (11.7 micro g/g), whereas NH(4)-N had opposite results with shallow injection having less (p = 0.045) NH(4)-N (102 micro g/g) than deep (133 micro g/g) injection. In the fall one year after the manure was applied, NO(3)-N and NH(4)-N were lower (p = 0.001) in the shallow injection than the deep injection. The net impact of manure placement on total N was that deep injection had 31, 59, and 44 more kg N ha(- 1) than the shallow injection treatment 12, 18, and 30 months after application, respectively. Deep manure injection did not impact soybean (Glycine max L.) yield, however corn (Zea mays L.) yield increased if N was limiting. The higher corn yield in the deep injected treatment was attributed to increased N use efficiency. Higher inorganic N amounts in the deep injection treatment were attributed to reduced N losses through ammonia volatilization, leaching, or denitrification. Results suggest that deep manure placement in glacial till soil may be considered a technique to increase energy, N use efficiency, and maintain surface and ground water quality. However, this technique may not work in glacial outwash soils due to the inability to inject into a rocky subsurface. PMID:19089718

  5. Harvesting Technique Affects Adipose-Derived Stem Cell Yield

    PubMed Central

    Iyyanki, Tejaswi; Hubenak, Justin; Liu, Jun; Chang, Edward I.; Beahm, Elisabeth K.; Zhang, Qixu

    2015-01-01

    Background The success of an autologous fat graft depends in part on its total stromal vascular fraction (SVF) and adipose-derived stem cells (ASCs). However, variations in the yields of ASCs and SVF cells as a result of different harvesting techniques and donor sites are poorly understood. Objective To investigate the effects of adipose tissue harvesting technique and donor site on the yield of ASCs and SVF cells. Methods Subcutaneous fat tissues from the abdomen, flank, or axilla were harvested from patients of various ages by mechanical liposuction, direct surgical excision, or Coleman's technique with or without centrifugation. Cells were isolated and then analyzed with flow cytometry to determine the yields of total SVF cells and ASCs (CD11b−, CD45−, CD34+, CD90+, D7-FIB+). Differences in ASC and total SVF yields were assessed with one-way analysis of variance. Differentiation experiments were performed to confirm the multilineage potential of cultured SVF cells. Results Compared with Coleman's technique without centrifugation, direct excision yielded significantly more ASCs (P < .001) and total SVF cells (P = .007); liposuction yielded significantly fewer ASCs (P < .001) and total SVF cells (P < .05); and Coleman's technique with centrifugation yielded significantly more total SVF cells (P < .005), but not ASCs. The total number of SVF cells in fat harvested from the abdomen was significantly larger than the number in fat harvested from the flank or axilla (P < .05). Cultured SVF cells differentiated to adipocytes, osteocytes, and chondrocytes. Conclusions Adipose tissue harvested from the abdomen through direct excision or Coleman's technique with centrifugation was found to yield the most SVF cells and ASCs. PMID:25791999

  6. Synergistic interactions of ecosystem services: florivorous pest control boosts crop yield increase through insect pollination.

    PubMed

    Sutter, Louis; Albrecht, Matthias

    2016-02-10

    Insect pollination and pest control are pivotal functions sustaining global food production. However, they have mostly been studied in isolation and how they interactively shape crop yield remains largely unexplored. Using controlled field experiments, we found strong synergistic effects of insect pollination and simulated pest control on yield quantity and quality. Their joint effect increased yield by 23%, with synergistic effects contributing 10%, while their single contributions were 7% and 6%, respectively. The potential economic benefit for a farmer from the synergistic effects (12%) was 1.8 times greater than their individual contributions (7% each). We show that the principal underlying mechanism was a pronounced pest-induced reduction in flower lifetime, resulting in a strong reduction in the number of pollinator visits a flower receives during its lifetime. Our findings highlight the importance of non-additive interactions among ecosystem services (ES) when valuating, mapping or predicting them and reveal fundamental implications for ecosystem management and policy aimed at maximizing ES for sustainable agriculture. PMID:26865304

  7. Assessment of Potential Yield andClimate Change Sensitivity of Peanut Crop in Cagayan Valley, Philippines using DSSAT Simulation Model

    NASA Astrophysics Data System (ADS)

    Balderama, O. F.

    2013-12-01

    Peanut is a major upland crop in Cagayan Valley and a leguminous crop that requires less water and therefore, considered an important crop in improving productivity of upland and rainfed areas. However, little information is available on the potential productivity of the crop and analysis on the production constraints including climate change sensitivity. This study was aimed to determine yield potential and production constraints of peanut crop in Cagayan Valley through the use of Decision Support System for Agrotechnology Transfer (DSSAT) simulation modeling; analyze yield gaps between simulated and actual yield levels and to provide decision support to further optimize peanut production under climate change condition. Site of experiment for model calibration and validation was located on-station at Isabela State University, Echague, Isabela. Rainfall and other climatic variables were monitored using a HOBO weather station (Automatic Weather Station) which is strategically installed inside experimental zone.The inputs required to run the CSM model include information on soil and weather conditions, crop management practices and cultivar specific genetic coefficients. In the first step,a model calibration was conducted to determine the cultivar coefficients for certain peanut cultivar that are normally grown in Cagayan Valley. Crop growth and yield simulation modeling was undertaken using the Decision Support System for Agro-Technology Transfer (DSSAT) for small seeded peanut (Pn9). An evaluation of the CSM-CROPGRO-peanut model was performed with data sets from peanut experiment conducted from December 2011 to April 2012. The model was evaluated in the estimation of potential yield of peanut under rainfed condition and low-nitrogen application. Yield potential for peanut limited only by temperature and solar radiation and no-water and nutrient stress, ranged from 3274 to 4805 kg per hectare for six planting dates (October 1, October 15, November 1, November 15

  8. Assessments of Maize Yield Potential in the Korean Peninsula Using Multiple Crop Models

    NASA Astrophysics Data System (ADS)

    Kim, S. H.; Myoung, B.; Lim, C. H.; Lee, S. G.; Lee, W. K.; Kafatos, M.

    2015-12-01

    The Korean Peninsular has unique agricultural environments due to the differences in the political and socio-economical systems between the Republic of Korea (SK, hereafter) and the Democratic Peoples' Republic of Korea (NK, hereafter). NK has been suffering from the lack of food supplies caused by natural disasters, land degradation and failed political system. The neighboring developed country SK has a better agricultural system but very low food self-sufficiency rate (around 1% of maize). Maize is an important crop in both countries since it is staple food for NK and SK is No. 2 maize importing country in the world after Japan. Therefore evaluating maize yield potential (Yp) in the two distinct regions is essential to assess food security under climate change and variability. In this study, we have utilized multiple process-based crop models capable of regional-scale assessments to evaluate maize Yp over the Korean Peninsula - the GIS version of EPIC model (GEPIC) and APSIM model that can be expanded to regional scales (APSIM regions). First we evaluated model performance and skill for 20 years from 1991 to 2010 using reanalysis data (Local Data Assimilation and Prediction System (LDAPS); 1.5km resolution) and observed data. Each model's performances were compared over different regions within the Korean Peninsula of different regional climate characteristics. To quantify the major influence of individual climate variables, we also conducted a sensitivity test using 20 years of climatology. Lastly, a multi-model ensemble analysis was performed to reduce crop model uncertainties. The results will provide valuable information for estimating the climate change or variability impacts on Yp over the Korean Peninsula.

  9. Spatial heterogeneity of soil biochar content affects soil quality and wheat growth and yield.

    PubMed

    Olmo, Manuel; Lozano, Ana María; Barrón, Vidal; Villar, Rafael

    2016-08-15

    Biochar (BC) is a carbonaceous material obtained by pyrolysis of organic waste materials and has been proposed as a soil management strategy to mitigate global warming and to improve crop productivity. Once BC has been applied to the soil, its imperfect and incomplete mixing with soil during the first few years and the standard agronomic practices (i.e. tillage, sowing) may generate spatial heterogeneity of the BC content in the soil, which may have implications for soil properties and their effects on plant growth. We investigated how, after two agronomic seasons, the spatial heterogeneity of olive-tree prunings BC applied to a vertisol affected soil characteristics and wheat growth and yield. During the second agronomic season and just before wheat germination, we determined the BC content in the soil by an in-situ visual categorization based on the soil darkening, which was strongly correlated to the BC content of the soil and the soil brightness. We found a high spatial heterogeneity in the BC plots, which affected soil characteristics and wheat growth and yield. Patches with high BC content showed reduced soil compaction and increased soil moisture, pH, electrical conductivity, and nutrient availability (P, Ca, K, Mn, Fe, and Zn); consequently, wheat had greater tillering and higher relative growth rate and grain yield. However, if the spatial heterogeneity of the soil BC content had not been taken into account in the data analysis, most of the effects of BC on wheat growth would not have been detected. Our study reveals the importance of taking into account the spatial heterogeneity of the BC content. PMID:27110980

  10. Genetic modification of plant cell walls to enhance biomass yield and biofuel production in bioenergy crops.

    PubMed

    Wang, Yanting; Fan, Chunfen; Hu, Huizhen; Li, Ying; Sun, Dan; Wang, Youmei; Peng, Liangcai

    2016-01-01

    Plant cell walls represent an enormous biomass resource for the generation of biofuels and chemicals. As lignocellulose property principally determines biomass recalcitrance, the genetic modification of plant cell walls has been posed as a powerful solution. Here, we review recent progress in understanding the effects of distinct cell wall polymers (cellulose, hemicelluloses, lignin, pectin, wall proteins) on the enzymatic digestibility of biomass under various physical and chemical pretreatments in herbaceous grasses, major agronomic crops and fast-growing trees. We also compare the main factors of wall polymer features, including cellulose crystallinity (CrI), hemicellulosic Xyl/Ara ratio, monolignol proportion and uronic acid level. Furthermore, the review presents the main gene candidates, such as CesA, GH9, GH10, GT61, GT43 etc., for potential genetic cell wall modification towards enhancing both biomass yield and enzymatic saccharification in genetic mutants and transgenic plants. Regarding cell wall modification, it proposes a novel groove-like cell wall model that highlights to increase amorphous regions (density and depth) of the native cellulose microfibrils, providing a general strategy for bioenergy crop breeding and biofuel processing technology. PMID:27269671

  11. The path of carbon in photosynthesis: improved crop yields with methanol.

    PubMed Central

    Nonomura, A M; Benson, A A

    1992-01-01

    Foliar sprays of aqueous 10-50% methanol increased growth and development of C3 crop plants in arid environments. The effects of low levels (< 1 ml per plant) of methanol were observed for weeks after the brief time necessary for its rapid metabolism. Within several hours, foliar treatment with methanol resulted in increased turgidity. Plants treated with nutrient-supplemented methanol showed up to 100% increases in yields when maintained under direct sunlight in desert agriculture. In the shade and when winter crops were treated with methanol, plants showed no improvement of growth. When repeatedly treated with nutrient-supplemented methanol, shaded plants showed symptoms of toxicity. Repeated methanol treatments with glycine caused increased turgidity and stimulated plant growth without injury under indirect sunlight, but indoors with artificial illumination, foliar damage developed after 48 hr. Addition of glycerophosphate to glycine/methanol solutions allowed treatment of artificially illuminated plants indoors without injury. Plants with C4 metabolism showed no increase in productivity by methanol treatment. Plants given many applications of aqueous methanol showed symptoms of nutrient deficiency. Supplementation with a source of nitrogen sustained growth, eliminating symptoms of deficiency. Adjustment of carbon/nitrogen ratios was undertaken in the field by decreasing the source of nitrogen in the final application, resulting in early maturation; concomitantly, irrigation requirements were reduced. PMID:1409701

  12. Impact of paper mill wastewater on soil properties and crop yield through lysimeter studies.

    PubMed

    Singh, P K; Ladwani, K; Ladwani, K; Deshbhratar, P B; Ramteke, D S

    2013-01-01

    Paper and pulp industries produce large quantities of wastewater which can have adverse effects on the receiving water systems. In the present study lysimeters were used and filled with different soils replicating natural soil horizons and provided with a leachate collection system. The physico-chemical characteristics of the soil in each lysimeter and the quality of wastewater before leaching were assessed. Treated wastewater was evaluated for crop irrigation, and was categorized according to the irrigation water class 'Increasing Problem to Severe Problem' with respect to salinity and specific ion toxicity. Sandy loam soils showed 96% chemical oxygen demand (COD) removal while clay loam soils removed 99% of COD, and the colour removal in both the cases was found to be 100%. Application of wastewater resulted in an increase of pH value, ranging from 6.2-7.6; the electrical conductivity (ECe) of saturated extracts was found to be 0.6-1.7 dS m(-1), and exchangeable sodium percentage (ESP) ranged from 7.8-11.1% in soils. Similarly, an increase in the organic carbon, available nitrogen, phosphorus and potash content of soils was observed when irrigated with wastewater. Wastewater irrigation showed increased grain and straw yield of jowar, wheat and moong. These results permit successful utilization of pulp and paper mill wastewater for crop production without damaging the soils. PMID:23837309

  13. Mapping Human-Dominated Landscapes: the Distribution and Yield of Major Crops of the World

    NASA Astrophysics Data System (ADS)

    Monfreda, C.; Ramankutty, N.; Foley, J. A.

    2005-12-01

    Croplands cover 18 million km2, an area the size of South America, and provide ecosystem goods and services essential to human well-being. Most global land-cover classifications group the diversity of croplands into a single or very few categories, thereby excluding critical information to answer key questions ranging from biodiversity conservation to food security to biogeochemical cycling. Information on land-use practices is even more limited. The relative lack of information about agricultural landscapes results partly from difficulties in using satellite data to identify individual crop types and land-use practices at a global scale. We address limitations common to remote-sensing classifications by distributing national, state, and county level statistics across a recently updated global dataset of cropland cover at 5 minute resolution. The resulting datasets depict the fractional harvested area and yield of twenty distinct crop types: maize, wheat, rice, sorghum, millet, barley, oats, soybeans, sunflower, rapeseed/canola, pulses, groundnuts/peanuts, oil palm, cassava, potatoes, sugar cane, sugar beets, tobacco, coffee, and cotton. These datasets represent the state of agriculture circa the year 2000 and will be made available for applications in ecological analysis, modeling, visualization, and education.

  14. Biochar application to temperate soils - effects on soil fertility and crop yield

    NASA Astrophysics Data System (ADS)

    Kloss, S.; Zehetner, F.; Feichtmair, S.; Wimmer, B.; Zechmeister-Boltenstern, S.; Kitzler, B.; Watzinger, A.; Soja, G.

    2012-04-01

    Biochar (BC) application to soil as a potential soil amendment is currently intensively explored. Depending on feedstock and highest treatment temperature (HTT), BC application to soil may contribute to the soil nutrient status by directly adding nutrients to the soil as well as by increasing pH, cation exchange and water holding capacity. These parameters are known to play an important role in the soil nutrient status and nutrient availability. A positive effect on plant growth after BC application to tropical soils has been observed repeatedly; however, the effect of BC application to soils in temperate climate regions is much less explored. We investigated the effect of BC to temperate soils and crop yield using a randomized pot experiment in a greenhouse with three agricultural soils (Planosol, Cambisol, Chernozem) and four BC types (from straw, mixed woodchips and vineyard pruning, all pyrolyzed at 525°C). In order to analyze the effect of pyrolysis temperature, we additionally applied vineyard pruning BC pyrolyzed at 400°C. Selected treatments were planted with mustard (Sinapis alba L.), followed by barley (Hordeum vulgare). Soil sampling was carried out after barley harvest. Investigated soil parameters included pH, electrical conductivity (EC), C/N ratio, cation exchange capacity (CEC), CAL-extractable P and K, EDTA extractable Cu, Fe, Mn, Zn as well as nitrogen supplying potential (NSP). Biomass production of the two crops was determined as well as its elemental composition. Biochar application (3% wood-based BC) caused a considerable pH increase for the acidic Planosol. The effect of BC application on CEC was dependent on the original status of the soil, notably soil pH and texture. 3 % BC application (wood) decreased CEC by 3.5 % and 10 % for the Chernozem and Cambisol, respectively, but increased CEC by 35 % for the acidic, sandy Planosol, which may be due to the strong liming effect found for the Planosol. BC application significantly raised CAL

  15. Assessment of crop yield losses in Punjab and Haryana using two years of continuous in-situ ozone measurements

    NASA Astrophysics Data System (ADS)

    Sinha, B.; Singh Sangwan, K.; Maurya, Y.; Kumar, V.; Sarkar, C.; Chandra, B. P.; Sinha, V.

    2015-01-01

    In this study we use a high quality dataset of in-situ ozone measurements at a suburban site called Mohali in the state of Punjab to estimate ozone related crop yield losses for wheat, rice, cotton and maize for Punjab and the neighbouring state Haryana for the years 2011-2013. We inter-compare crop yield loss estimates according to different exposure metrics such as AOT40 and M7 for the two major crop growing seasons of Kharif (June-October) and Rabi (November-April) and establish a new crop yield exposure relationship for South Asian wheat and rice cultivars. These are a factor of two more sensitive to ozone induced crop yield losses compared to their European and American counterparts. Relative yield losses based on the AOT40 metrics ranged from 27-41% for wheat, 21-26% for rice, 9-11% for maize and 47-58% for cotton. Crop production losses for wheat amounted to 20.8 million t in fiscal year 2012-2013 and 10.3 million t in fiscal year 2013-2014 for Punjab and Haryana jointly. Crop production losses for rice totalled 5.4 million t in fiscal year 2012-2013 and 3.2 million t year 2013-2014 for Punjab and Haryana jointly. The Indian National Food Security Ordinance entitles ~ 820 million of India's poor to purchase about 60 kg of rice/wheat per person annually at subsidized rates. The scheme requires 27.6 Mt of wheat and 33.6 Mt of rice per year. Mitigation of ozone related crop production losses in Punjab and Haryana alone could provide >50% of the wheat and ~10% of the rice required for the scheme. The total economic cost losses in Punjab and Haryana amounted to USD 6.5 billion in the fiscal year 2012-2013 and USD 3.7 billion in the fiscal year 2013-2014. This economic loss estimate represents a very conservative lower limit based on the minimum support price of the crop, which is lower than the actual production costs. The upper limit for ozone related crop yield losses in entire India currently amounts to 3.5-20% of India's GDP. Mitigation of high surface ozone

  16. Cellulosic Biofuel Production with Winter Cover Crops: Yield and Nitrogen Implications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interest in renewable energy sources derived from plant biomass is increasing. Growing cover crops after harvest of the primary crop has been proposed as a solution to producing cellulosic biomass on existing crop-producing land without reducing food-harvest potential. Growing cover crops is a recom...

  17. Evaluation of crop yield loss of floods based on water turbidity index with multi-temporal HJ-CCD images

    NASA Astrophysics Data System (ADS)

    Gu, Xiaohe; Xu, Peng; Wang, Lei; Wang, Xiuhui

    2015-12-01

    Paddy is one of the most important food crops in China. Due to the intensive planting in the surrounding of rivers and lakes, paddy is vulnerable to flooding stress. The research on predicting crop yield loss derived from flooding stress will help the adjustment of crop planting structure and the claims of agricultural insurance. The paper aimed to develop a method of estimating yield loss of paddy derived from flooding by multi-temporal HJ CCD images. At first, the water pixels after flooding were extracted, from which the water line (WL) of turbid water pixels was generated. Secondly, the water turbidity index (WTI) and perpendicular vegetation index (PVI) was defined and calculated. By analyzing the relation among WTI, PVI and paddy yield, the model of evaluating yield loss of flooding was developed. Based on this model, the spatial distribution of paddy yield loss derived from flooding was mapped in the study area. Results showed that the water turbidity index (WTI) could be used to monitor the sediment content of flood, which was closely related to the plant physiology and per unit area yield of paddy. The PVI was the good indicator of paddy yield with significant correlation (0.965). So the PVI could be used to estimate the per unit area yield before harvesting. The PVI and WTI had good linear relation, which could provide an effective, practical and feasible method for monitoring yield loss of waterlogged paddy.

  18. Retaining biodiversity in intensive farmland: epiphyte removal in oil palm plantations does not affect yield

    PubMed Central

    Prescott, Graham W; Edwards, David P; Foster, William A

    2015-01-01

    The expansion of agriculture into tropical forest frontiers is one of the primary drivers of the global extinction crisis, resulting in calls to intensify tropical agriculture to reduce demand for more forest land and thus spare land for nature. Intensification is likely to reduce habitat complexity, with profound consequences for biodiversity within agricultural landscapes. Understanding which features of habitat complexity are essential for maintaining biodiversity and associated ecosystem services within agricultural landscapes without compromising productivity is therefore key to limiting the environmental damage associated with producing food intensively. Here, we focus on oil palm, a rapidly expanding crop in the tropics and subject to frequent calls for increased intensification. One promoted strategy is to remove epiphytes that cover the trunks of oil palms, and we ask whether this treatment affects either biodiversity or yield. We experimentally tested this by removing epiphytes from four-hectare plots and seeing if the biodiversity and production of fruit bunches 2 months and 16 months later differed from equivalent control plots where epiphytes were left uncut. We found a species-rich and taxonomically diverse epiphyte community of 58 species from 31 families. Epiphyte removal did not affect the production of fresh fruit bunches, or the species richness and community composition of birds and ants, although the impact on other components of biodiversity remains unknown. We conclude that as they do not adversely affect palm oil production, the diverse epiphyte flora should be left uncut. Our results underscore the importance of experimentally determining the effects of habitat complexity on yield before introducing intensive methods with no discernible benefits. PMID:26045947

  19. Retaining biodiversity in intensive farmland: epiphyte removal in oil palm plantations does not affect yield.

    PubMed

    Prescott, Graham W; Edwards, David P; Foster, William A

    2015-05-01

    The expansion of agriculture into tropical forest frontiers is one of the primary drivers of the global extinction crisis, resulting in calls to intensify tropical agriculture to reduce demand for more forest land and thus spare land for nature. Intensification is likely to reduce habitat complexity, with profound consequences for biodiversity within agricultural landscapes. Understanding which features of habitat complexity are essential for maintaining biodiversity and associated ecosystem services within agricultural landscapes without compromising productivity is therefore key to limiting the environmental damage associated with producing food intensively. Here, we focus on oil palm, a rapidly expanding crop in the tropics and subject to frequent calls for increased intensification. One promoted strategy is to remove epiphytes that cover the trunks of oil palms, and we ask whether this treatment affects either biodiversity or yield. We experimentally tested this by removing epiphytes from four-hectare plots and seeing if the biodiversity and production of fruit bunches 2 months and 16 months later differed from equivalent control plots where epiphytes were left uncut. We found a species-rich and taxonomically diverse epiphyte community of 58 species from 31 families. Epiphyte removal did not affect the production of fresh fruit bunches, or the species richness and community composition of birds and ants, although the impact on other components of biodiversity remains unknown. We conclude that as they do not adversely affect palm oil production, the diverse epiphyte flora should be left uncut. Our results underscore the importance of experimentally determining the effects of habitat complexity on yield before introducing intensive methods with no discernible benefits. PMID:26045947

  20. Understanding the Propagation of GCM and Downscaling Uncertainty for Projecting Crop Yield: A Nationwide Analysis over India

    NASA Astrophysics Data System (ADS)

    Sharma, T.; Murari, H. V.; H, V.; Karmakar, S.; Ghosh, S.; Soora, N. K.

    2015-12-01

    General Circulation Models (GCM) play an important role in assessing the impacts of climate change at global scale; however, coarser resolution limits their direct application at regional scale. To understand the climate variability at regional scale, different downscaling techniques (such as dynamical and statistical) have been developed which use the GCM outputs as boundary condition to produce finer resolution climate projections. Although, both dynamical and statistical downscaling techniques have proven to be able to capture the climate variability at regional scale; there are certain uncertainties lying in their projections especially for a region like India which have complex terrain and climatic pattern. Here, the uncertainties, resulting from the use of multiple GCM and downscaling models, are quantified with the assessment of impacts on regional crop yield. Two crop models with different complexity-Decision Support System for Agro-technology Transfer (DSSAT) and Infocrop, are used, forced by dynamically (CORDEX, COordinated Regional climate Downscaling EXperiment) and statistically (Kannan and Ghosh, 2011; Salvi et al., 2013) downscaled data derived from multiple GCM's. Advantage of these crop models is their ability to capture complexity of Indian condition. Yields of major crops in India, such as, rice, wheat and maize have been considered in the crop model and the impacts of climate change are assessed on their yields. The uncertainties in projected crop yields are also quantified, which must be incorporated for deriving vulnerability and risk maps for crop-climate assessments. This may further help to determine different crop management practices in order to reduce adverse impacts of climate change in future.

  1. Effect of chemical and mechanical weed control on cassava yield, soil quality and erosion under cassava cropping system

    NASA Astrophysics Data System (ADS)

    Islami, Titiek; Wisnubroto, Erwin; Utomo, Wani

    2016-04-01

    Three years field experiments were conducted to study the effect of chemical and mechanical weed control on soil quality and erosion under cassava cropping system. The experiment were conducted at University Brawijaya field experimental station, Jatikerto, Malang, Indonesia. The experiments were carried out from 2011 - 2014. The treatments consist of three cropping system (cassava mono culture; cassava + maize intercropping and cassava + peanut intercropping), and two weed control method (chemical and mechanical methods). The experimental result showed that the yield of cassava first year and second year did not influenced by weed control method and cropping system. However, the third year yield of cassava was influence by weed control method and cropping system. The cassava yield planted in cassava + maize intercropping system with chemical weed control methods was only 24 t/ha, which lower compared to other treatments, even with that of the same cropping system used mechanical weed control. The highest cassava yield in third year was obtained by cassava + peanuts cropping system with mechanical weed control method. After three years experiment, the soil of cassava monoculture system with chemical weed control method possessed the lowest soil organic matter, and soil aggregate stability. During three years of cropping soil erosion in chemical weed control method, especially on cassava monoculture, was higher compared to mechanical weed control method. The soil loss from chemical control method were 40 t/ha, 44 t/ha and 54 t/ha for the first, second and third year crop. The soil loss from mechanical weed control method for the same years was: 36 t/ha, 36 t/ha and 38 t/ha. Key words: herbicide, intercropping, soil organic matter, aggregate stability.

  2. [Effects of rotations and different green manure utilizations on crop yield and soil fertility].

    PubMed

    Yao, Zhi-yuan; Wang, Zheng; Li, Jing; Yu, Chang-wei; Cao, Qun-hu; Cao, Wei-dong; Gao, Ya-jun

    2015-08-01

    A 4-year field experiment was conducted to investigate the influence of three rotation systems and three corresponding leguminous green manure (LGM) application methods on wheat yield and soil properties. The rotation patterns were summer fallow--winter wheat (SW), LGM-- winter wheat (LW) and LGM--spring maize--winter wheat (LMW). The three LGM application methods of LW included: early mulch, early incorporation and late incorporation while the three LGM application methods of LMW were: stalk mulch, stalk incorporation and stalk move-away. The results indicated that for LW, LGM consumed more soil water, thus the wheat yield was not stable. The nitrate storage in 0-200 cm soil after wheat harvest was significantly higher than that of the others, indicating an increasing risk of nitrate leaching. Early mulch under LW had the highest soil organic carbon (SOC) content and storage of SOC (SSOC) in 0-20 cm soil. For LMW, wheat yield was comparatively stable among years, because of higher water storage before wheat seeding, and the nitrate storage in 0-200 cm soil after wheat harvest was significantly lower than LW, which decreased the risk of nitrate leaching. Stalk mulch had higher SOC content in 0-20 cm soil after wheat harvest compared with move-away. In addition, compared with the soil when the experiment started, stalk much also increased SSOC in 0-20 cm soil. In conclusion, LMW with stalk mulch could increase soil water storage, stabilize crop yield, improve soil fertility and decrease 0-200 cm soil nitrate storage. This system could be treated as a good alternative for areas with similar climate. PMID:26685595

  3. Field testing soybeans for residual effects of air pollution and seed size on crop yield

    SciTech Connect

    Howell, R.K.; Rose, L.P. Jr.; Leffel, R.C.

    1980-01-01

    Mean seed weights (g/100 seeds) for four soybean (Glycine max (L.) Merr.), cultivars grown in 1973 and 1974 in cylindrical open-top field chambers that provided carbon-filtered air were significantly greater (17.2) than from plants grown in nonfiltered air in chambers (15.1), or in conventional plots without chambers (15.7). Using this seed, as experiment was designed to answer three questions: (i) does air quality influence seed yields from subsequent plants; (ii) do seed size differences, possibly induced by air pollutants, influence subsequent seed yields; (iii) is there a yield advantage from planting large seed vs an original lot of seed. This experiment was designed as a split-split plot with six replications. The whole plot treatments were the four cultivars; the split-plot treatments consisted of the nine factorial combinations of three seed sizes and three environments. The split-split plot treatment was a comparison between the specified seed size and an original lot of the seed from which the specific seed size was obtained. Six seeds per 30 cm of row were planted and evaluated in a field experiment near Queenstown, Maryland, in 1975. We found no residual air quality effects on subsequent seed yields. Differences in seed size observed for different air qualities did not significantly affect yields. In general, there was no significant yield advantage for plants grown from a selected seed size as compared with the original lot seed.

  4. Maximizing plant density affects broccoli yield and quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased demand for fresh market bunch broccoli (Brassica oleracea L. var. italica) has led to increased production along the United States east coast. Maximizing broccoli yields is a primary concern for quickly expanding southeastern commercial markets. This broccoli plant density study was carr...

  5. A novel method of identification of high-yield crop cultivars using correlation between delayed fluorescence and photosynthesis capacity

    NASA Astrophysics Data System (ADS)

    Wang, Junsheng; Xu, Wenhai; Li, Ying; Zhang, Lingrui

    2008-12-01

    Crop breeding and variety analysis play the important role in the national economy. A lot of sample data and typical probability distribution are needed in the conventional methods to evaluate the high-yield crop cultivars such as correlation analysis, regression analysis and grey relational grade analysis etc, which are difficult to be realized. Delayed fluorescence (DF) can be used to evaluate plant photosynthesis. The current investigation has revealed that there is a good linear correlation between DF and photosynthesis capacity. More importantly, the slopes of linear fit of the correlationship for different yield varieties are different. Four known yield crop cultivars from each of the two different species (Maize and Soybean) are selected as samples to be analyzed. The statistical results show that the slope of high-yield variety is smaller than that of low-yield. We thus conclude that the slope of linear fit of correlation between DF and photosynthesis capacity is an excellent marker for high-yield crop cultivars identification. Compared with the conventional methods, the presented method needs less samples and it's fast and easy to be measured.

  6. Long-term sediment yield from small catchment in southern Brazil affected by land use and soil management changes.

    NASA Astrophysics Data System (ADS)

    Gomes Minella, Jean Paolo; Henrique Merten, Gustavo; Alessandra Peixoto de Barros, Claudia; Dalbianco, Leandro; Ramon, Rafael; Schlesner, Alexandre

    2015-04-01

    Soil erosion and sediment yield are the main cause of soil degradation in Brazil. Despite this, there is a lack of information about the effects of the soil management on the hydrology and sediment yield at catchment scale. This study aimed to investigate the long-term relationship between the land use and sediment yield in a small catchment with significant changes in soil management, and its impacts on soil erosion and sediment yield. To account the anthropogenic and climatic effects on sediment yield were monitored precipitation, stream flow and suspended sediment concentration during thirteen years (2002 and 2014) at 10 minutes interval and the changes that occurred each year in the land use and soil management. Despite the influence of climate on the sediment yield, the results clearly show three distinct periods affected by the land use and soil management changes during this this period. In the first four years (2002-2004) the predominant land use was the tobacco with traditional soil management, where the soils are plough every year and without winter cover crop. In this period the sediment yield reached the order of 160 t.ha-1.y-1. In the period of 2005-2009, a soil conservation program introduced the adoption of minimum tillage in the catchment and the sediment yield decrease to 70 t.ha-1.y-1. In the last period (2010-2014) there was a partial return to the traditional soil management practices with an increase trend in sediment yield. However, there was also an increase in reforestation areas with positive effect in reducing erosion and sediment yield. The magnitude order of sediment yield in this period was 100 t.ha-1.y-1. The long term sediment yield data was able to demonstrate the impact of the improved management practices in reducing soil erosion and sediment yield. The results allowed a good understanding of the changing sediment dynamics and soil erosion at catchment scale.

  7. The variation of the water deficit during the winter wheat growing season and its impact on crop yield in the North China Plain.

    PubMed

    Wu, Jianjun; Liu, Ming; Lü, Aifeng; He, Bin

    2014-11-01

    The North China Plain (NCP) is one of the main agricultural areas in China. However, it is also widely known for its water shortages, especially during the winter wheat growing season. Recently, climate change has significantly affected the water environment for crop growth. Analyzing the changes in the water deficit, which is only affected by climate factor, will help to improve water management in the NCP. In this study, the Decision Support System for Agrotechnology Transfer (DSSAT) was used to investigate the variations in the water deficit during the winter wheat growing season from 1961 to 2010 in 12 selected stations in the NCP. To represent the changes in the water deficit without any artificial affection, the rainfed simulation was used. Over the past 50 years, the average temperature during the winter wheat growing season increased approximately 1.42 °C. The anthesis date moved forward approximately 7-10 days and to late April, which increased the water demand in April. Precipitation in March and May showed a positive trend, but there was a negative trend in April. The water deficit in late April and early May became more serious than before, with an increasing trend of more than 0.1 mm/year. In addition, because the heading stage, which is very important to crop yield of winter wheat, moved forward, the impact of water deficit in late April was more serious to crop yield. PMID:24531705

  8. The variation of the water deficit during the winter wheat growing season and its impact on crop yield in the North China Plain

    NASA Astrophysics Data System (ADS)

    Wu, Jianjun; Liu, Ming; Lü, Aifeng; He, Bin

    2014-02-01

    The North China Plain (NCP) is one of the main agricultural areas in China. However, it is also widely known for its water shortages, especially during the winter wheat growing season. Recently, climate change has significantly affected the water environment for crop growth. Analyzing the changes in the water deficit, which is only affected by climate factor, will help to improve water management in the NCP. In this study, the Decision Support System for Agrotechnology Transfer (DSSAT) was used to investigate the variations in the water deficit during the winter wheat growing season from 1961 to 2010 in 12 selected stations in the NCP. To represent the changes in the water deficit without any artificial affection, the rainfed simulation was used. Over the past 50 years, the average temperature during the winter wheat growing season increased approximately 1.42 °C. The anthesis date moved forward approximately 7-10 days and to late April, which increased the water demand in April. Precipitation in March and May showed a positive trend, but there was a negative trend in April. The water deficit in late April and early May became more serious than before, with an increasing trend of more than 0.1 mm/year. In addition, because the heading stage, which is very important to crop yield of winter wheat, moved forward, the impact of water deficit in late April was more serious to crop yield.

  9. Spatial Variation in Carbon and Nitrogen in Cultivated Soils in Henan Province, China: Potential Effect on Crop Yield

    PubMed Central

    Zhang, Xuelin; Wang, Qun; Gilliam, Frank S.; Wang, Yilun; Cha, Feina; Li, Chaohai

    2014-01-01

    Improved management of soil carbon (C) and nitrogen (N) storage in agro-ecosystems represents an important strategy for ensuring food security and sustainable agricultural development in China. Accurate estimates of the distribution of soil C and N stores and their relationship to crop yield are crucial to developing appropriate cropland management policies. The current study examined the spatial variation of soil organic C (SOC), total soil N (TSN), and associated variables in the surface layer (0–40 cm) of soils from intensive agricultural systems in 19 counties within Henan Province, China, and compared these patterns with crop yield. Mean soil C and N concentrations were 14.9 g kg−1 and 1.37 g kg−1, respectively, whereas soil C and N stores were 4.1 kg m−2 and 0.4 kg m−2, respectively. Total crop production of each county was significantly, positively related to SOC, TSN, soil C and N store, and soil C and N stock. Soil C and N were positively correlated with soil bulk density but negatively correlated with soil porosity. These results indicate that variations in soil C could regulate crop yield in intensive agricultural systems, and that spatial patterns of C and N levels in soils may be regulated by both climatic factors and agro-ecosystem management. When developing suitable management programs, the importance of soil C and N stores and their effects on crop yield should be considered. PMID:25289703

  10. Effects of film mulch and soil pesticides on nematodes, weeds, and yields of vegetable crops.

    PubMed

    Johnson, A W; Jaworski, C A; Glaze, N C; Sumner, D R; Chalfant, R B

    1981-04-01

    Field plots in Tifton loamy sand were treated with various soil pesticides in 1973 and 1974 and either left exposed or covered with biodegradable flint mulch. Test crops were cantaloup, slicing and pickling cucumber, squash, and sweet corn. Overhead sprinkler irrigation was used in 1973, and trickle irrigation under the film mulch was used on sweet corn in 1974. Soil was assayed for nematodes, and roots of plants were evaluated for damage by root-knot nematodes. Nematode populations were reduced by soil treatment with an organic phosphate or carbamate nematicide-herbicide-fungicide combination (NHF), DD-MENCS, methyl bromide-chloropicrin (MBR-CP), ethoprop, carbofuran, and sodium azide + ethoprop or carbofuran. Sodium azide, sodium azide + ethoprop or carbofuran, ethoprop, and carbofuran were less effective than DD-MENCS, MBR-CP, attd the NHF combination. The NHF combination controlled grasses and broadteaf weeds as effectively as the herbicide alone. Growth and yield were greatest when nematodes and weeds were controlled. Yields of marketable vegetables were highest from plants in plots treated with DD-MENCS with a film mulch. PMID:19300735

  11. A photorespiratory bypass increases plant growth and seed yield in biofuel crop Camelina sativa

    DOE PAGESBeta

    Dalal, Jyoti; Lopez, Harry; Vasani, Naresh B.; Hu, Zhaohui; Swift, Jennifer E.; Yalamanchili, Roopa; Dvora, Mia; Lin, Xiuli; Xie, Deyu; Qu, Rongda; et al

    2015-10-29

    Camelina sativa is an oilseed crop with great potential for biofuel production on marginal land. The seed oil from camelina has been converted to jet fuel and improved fuel efficiency in commercial and military test flights. Hydrogenation-derived renewable diesel from camelina is environmentally superior to that from canola due to lower agricultural inputs, and the seed meal is FDA approved for animal consumption. However, relatively low yield makes its farming less profitable. Our study is aimed at increasing camelina seed yield by reducing carbon loss from photorespiration via a photorespiratory bypass. Genes encoding three enzymes of the Escherichia coli glycolatemore » catabolic pathway were introduced: glycolate dehydrogenase (GDH), glyoxylate carboxyligase (GCL) and tartronic semialdehyde reductase (TSR). These enzymes compete for the photorespiratory substrate, glycolate, convert it to glycerate within the chloroplasts, and reduce photorespiration. As a by-product of the reaction, CO2 is released in the chloroplast, which increases photosynthesis. Camelina plants were transformed with either partial bypass (GDH), or full bypass (GDH, GCL and TSR) genes. Furthermore, transgenic plants were evaluated for physiological and metabolic traits.« less

  12. Evaluating the effects of electroporation pre-treatment on the biogas yield from ley crop silage.

    PubMed

    Lindmark, Johan; Lagerkvist, Anders; Nilsson, Erik; Carlsson, My; Thorin, Eva; Dahlquist, Erik

    2014-12-01

    Exploiting the full biogas potential of some types of biomass is challenging. The complex structures of lignocellulosic biomass are difficult to break down and thus require longer retention times for the nutrients to become biologically available. It is possible to increase the digestibility of the substrate by pre-treating the material before digestion. This paper explores a pre-treatment of ley crop silage that uses electrical fields, known as electroporation (EP). Different settings of the EP equipment were tested, and the results were analyzed using a batch digestion setup. The results show that it is possible to increase the biogas yield with 16 % by subjecting the substrates to 65 pulses at a field strength of 96 kV/cm corresponding to a total energy input of 259 Wh/kg volatile solid (VS). However, at 100 pulses, a lower field strength of 48 kV/cm and the same total energy input, no effects of the treatment were observed. The energy balance of the EP treatment suggests that the yield, in the form of methane, can be up to double the electrical energy input of the process. PMID:25209554

  13. Factors Affecting Soil Microbial Community Structure in Tomato Cropping Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil and rhizosphere microbial communities in agroecosystems may be affected by soil, climate, plant species, and management. We identified some of the most important factors controlling microbial biomass and community structure in an agroecosystem utilizing tomato plants with the following nine tre...

  14. Biomass yield as affected by wheat harvest method

    SciTech Connect

    Allen, R.R.; Hollingsworth, L.D.

    1982-12-01

    Wheat biomass yield and the portions recoverable by different harvesting methods were investigated at Bushland, TX. Where all above-ground dry matter was removed by hand and threshed with a small bundle thresher; the grain, straw and chaff portions averaged about 40, 50, and 10, respectively, of the total biomass. When clipping samples at a simulated combine harvesting height (13-14 inches), the remaining stubble amounts ranged from 1500 to 3000 pounds per acre when grain yield levels averaged 3000 to 6000 pounds per acre. In treatments where the stubble was swathed and baled after conventional combine harvesting, the straw yields ranged from 2000 to 2800 pounds per acre. The bales accounted for 34 to 46 of the ''material other than grain.'' There was about 2000 pounds per acre of stubble remaining below the 3 to 4 inch swather cutting height. In treatments where the combine cutter-bar was operated near ground level (2 to 3 inches) and all straw discharge was caught (whole plant combining), the catchings ranged from 65 to 89 of the ''material other than grain.'' The catching weights ranged from 3900 to 6000 pounds per acre.

  15. [Evaluation of seasonal dynamics of crop yield in agrocenoses on the basis of satellite data and mathematical model].

    PubMed

    Pis'man, T I; Botvich, I Iu; Sid'ko, A F

    2014-01-01

    An integrated approach based on satellite remote sensing data and the results of mathematical model analysis was tested for applicability in evaluating the crop yield and total of phytomass of agrocenosis and identifying its type. The dynamics of the normalized difference vegetation index (NDVI) and the total aboveground phytomass of agrocenosis proved to be qualitatively similar. An analysis performed using the mathematical model and taking into account air temperature showed the possibility of making and refining prognosis of crop yield. In this course, the vegetative and generative parts of the agrocenosis were distinguished, and it was found that the model data matched the ground survey data under optimal environmental conditions. PMID:25735172

  16. The Potential Use of Summer Rainfall Enhancement in Illinois. Part I: A Field Experiment to Define Responses of Crop Yields to Increased Rainfall.

    NASA Astrophysics Data System (ADS)

    Changnon, Stanley A.; Hollinger, Steven E.

    1993-03-01

    An assessment was made of factors affecting the use of cloud seeding to increase summer (June-August) rainfall for improved corn and soybean yields in Illinois. Crop yields from a five-year agricultural field experiment involving nine levels of rain increases were compared with yields produced under natural rainfall. The sampled years (1987 91) included a wide range of summer weather conditions, including extremely hot and dry (1988) and very wet and cool (1990). Since the types of growing seasons sampled represented only 30% of all types, caution must be used in interpreting the results and applying them to other years.Additional water of 10%, 25%, or 40% of each day's actual rainfall was applied after each rain. Additional water was also applied only to certain rains, depending on whether they were light, moderate, or heavy. The best treatment, based on performance in all years and considering both treated and untreated crops, was a 25% rain increase applied on days with moderate rain (2.5 mm 2.53 cm). However, it was only marginally better than the natural rainfall. The best treatment for soybeans alone, based on the average yields for 1987 90, was the natural, unmodified rainfall, whereas that for corn was 10% 40% increases only on heavy-rain days. In general, rain increases of 10% had little yield effect, and 40% increases applied in all years were found damaging in wetter years. However, in extremely dry summers, the 40% rain increases were the best for both crops. The best treatment in any given summer varied by the type and timing of rain conditions and crop. Selection of the best treatment to use in any summer would require the capability to predict the amount and timing of summer rainfall by 1 June.

  17. Agro-economic yield of taro clones in Brazil, propagated with different types of cuttings, in three crop seasons.

    PubMed

    Zárate, Néstor A Heredia; Vieira, Maria C; Tabaldi, Luciane A; Vieira, Danilo A Heredia; Jorge, Rosimeire P G; Salles, Natália A

    2013-01-01

    The experimental studies were conducted in 2007-2008, 2008-2009 and 2009-2010 crop seasons, in order to know the agro-economic yield of 'Chinês' and "Macaquinho" taro clones, propagated using huge, extra, large, medium, small and tiny cormels. The harvest was done on average on 202 days after planting, in three crop seasons. Based on the joint analysis of variance carried out, it was observed that taro clones showed significant differences in the yield of fresh and dry weight of leaves, cormels, and commercial and non-commercial comels; besides, there were significant differences in yield of a crop season to another and the size of the cuttings induced significant differences in yield. In the conditions that the experiments were conducted, and considering the highest average yield of fresh weight of commercial cormels (28.69 t.ha-1) and highest net income (US $14,741.14) correspondent to the three crop seasons, it is recommended to cultivate 'Macaquinho' clone using small cuttings in propagation. PMID:23828356

  18. Incorporating climate change trends to near future variability of crop yields in Iberia Peninsula

    NASA Astrophysics Data System (ADS)

    Capa-Morocho, Mirian; Baethgen, Walter E.; Fernandes, Kátia; Rodríguez-Fonseca, Belén; Ruiz-Ramos, Margarita

    2016-04-01

    In this study, we analyze the effects of near future climate variability on cropping systems in Iberian Peninsula (IP). For this purpose, we generated climate sequences that simulate realistic variability on annual to decadal time scales. The sequences incorporate nonlinear climate change trends, using statistical methods and and an ensemble of global climate models from the Coupled Model Intercomparison Project (CMIP5). Then, the climate sequences are temporal downscaled into daily weather data and used as inputs to crop models. As case study, we evaluate the impacts of plausible future climate scenarios on rain-fed wheat yield two agricultural locations in IP. We adapted the method by Greene et al., (2012 and 2015) for informing climate projections for the coming decades with a combination of seasonal to interannual and anthropogenically forced climate change information for accounting the Near-term Climate Change. Long-term data containing solar radiation, maximum and minimum temperature and rainfall are needed to apply this method. The climate variability observed was decomposed into long-range trend, decadal and interannual variability to understand the relative importance of each time scale. The interannual variability was modeled based on the observational records. The results of this study may have important implications on public and private sectors to analyze the probabilistic projections of impacts and agronomic adaptations of near future climate variability in Iberian Peninsula. This study has been funded by MACSUR project from FACCE-JPI. References Greene, A.M., Goddard, L., Gonzalez, P.L., Ines, A.V. and Chryssanthacopoulos, J., 2015.A climate generator for agricultural planning in southeastern South America.Agricultural and Forest Meteorology, 203: 217-228. Greene, A.M., Hellmuth, M. and Lumsden, T., 2012. Stochastic decadal climate simulations for the Berg and Breede water management areas, western Cape province, South Africa. Water Resources

  19. Using Ancient Traits to Convert Soil Health into Crop Yield: Impact of Selection on Maize Root and Rhizosphere Function

    PubMed Central

    Schmidt, Jennifer E.; Bowles, Timothy M.; Gaudin, Amélie C. M.

    2016-01-01

    The effect of domestication and modern breeding on aboveground traits in maize (Zea mays) has been well-characterized, but the impact on root systems and the rhizosphere remain unclear. The transition from wild ecosystems to modern agriculture has focused on selecting traits that yielded the largest aboveground production with increasing levels of crop management and nutrient inputs. Root morphology, anatomy, and ecophysiological processes may have been affected by the substantial environmental and genetic shifts associated with this transition. As a result, root and rhizosphere traits that allow more efficient foraging and uptake in lower synthetic input environments might have been lost. The development of modern maize has led to a shift in microbiome community composition, but questions remain as to the dynamics and drivers of this change during maize evolution and its implications for resource acquisition and agroecosystem functioning under different management practices. Better understanding of how domestication and breeding affected root and rhizosphere microbial traits could inform breeding strategies, facilitate the sourcing of favorable alleles, and open new frontiers to improve resource use efficiency through greater integration of root development and ecophysiology with agroecosystem functioning. PMID:27066028

  20. Using Ancient Traits to Convert Soil Health into Crop Yield: Impact of Selection on Maize Root and Rhizosphere Function.

    PubMed

    Schmidt, Jennifer E; Bowles, Timothy M; Gaudin, Amélie C M

    2016-01-01

    The effect of domestication and modern breeding on aboveground traits in maize (Zea mays) has been well-characterized, but the impact on root systems and the rhizosphere remain unclear. The transition from wild ecosystems to modern agriculture has focused on selecting traits that yielded the largest aboveground production with increasing levels of crop management and nutrient inputs. Root morphology, anatomy, and ecophysiological processes may have been affected by the substantial environmental and genetic shifts associated with this transition. As a result, root and rhizosphere traits that allow more efficient foraging and uptake in lower synthetic input environments might have been lost. The development of modern maize has led to a shift in microbiome community composition, but questions remain as to the dynamics and drivers of this change during maize evolution and its implications for resource acquisition and agroecosystem functioning under different management practices. Better understanding of how domestication and breeding affected root and rhizosphere microbial traits could inform breeding strategies, facilitate the sourcing of favorable alleles, and open new frontiers to improve resource use efficiency through greater integration of root development and ecophysiology with agroecosystem functioning. PMID:27066028

  1. Crop diversification, tillage, and management system influences on spring wheat yield and soil water use

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Depleted soil quality, decreased water availability, and increased weed competition constrain spring wheat production in the northern Great Plains. Integrated crop management systems are necessary for improved crop productivity. We conducted a field experiment from 2004-2010 comparing productivity...

  2. Sheep grazing wheat summer fallow and the impact on soil nitrogen, moisture, and crop yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When incorporating targeted grazing into farming systems, livestock producers and farm operators need assurance that the benefits from their activities are worth their investments. Cropping systems were once integrated with livestock production: livestock gained forage value from crop aftermath, c...

  3. Potato Production as Affected by Crop Parameters and Meteoro Logical Elements

    NASA Astrophysics Data System (ADS)

    Pereira, André B.; Villa Nova, Nilson A.; Pereira, Antonio R.

    Meteorological elements directly influence crop potential productivity, regulating its transpiration, photosynthesis, and respiration processes in such a way as to control the growth and development of the plants throughout their physiological mechanisms at a given site. The interaction of the meteorological factors with crop responses is complex and has been the target of attention of many researchers from all over the world. There is currently a great deal of interest in estimating crop productivity as a function of climate by means of different crop weather models in order to help growers choose planting locations and timing to produce high yields with good tuber quality under site-specific atmospheric conditions. In this manuscript an agrometeorological model based on maximum carbon dioxide assimilation rates for C3 plants, fraction of photosynthetically active radiation, air temperature, photoperiod duration, and crop parameters is assessed as to its performance under tropical conditions. Crop parameters include leaf areaand harvest indexes, dry matter content of potato tubers, and crop cycles to estimate potato potential yields. Productivity obtained with the cultivar Itararé, grown with adequate soil water supply conditions at four different sites in the State of São Paulo (Itararé, Piracicaba, TatuÍ, and São Manuel), Brazil, were used to test the model. The results showed thatthe agrometeorological model tested under the climatic conditions of the State of São Paulo in general underestimated irrigated potato yield by less than 10%.This justifies the recommendation to test the performance of the model in study in other climaticregions for different crops and genotypes under optimal irrigationconditions in further scientific investigations. We reached the conclusion that the agrometeorological model taking into account information on leaf area index, photoperiod duration, photosynthetically active radiation and air temperature is feasible to estimate

  4. Climate Change Impacts on Water and Crop Yields in the Glacial Dominated Beas River Basin in India

    NASA Astrophysics Data System (ADS)

    Holman, I.; Remesan, R.; Ojha, C. S. P. S.; Adeloye, A. J.

    2014-12-01

    Himalayan valleys are confronting severe climate change related issues (floods in summer, flash flood and landslides, water scarcity in higher altitudes) because of fluctuating monsoon precipitation and increasing seasonal temperatures. In this study, the Soil and Water Assessment Tool (SWAT) model is applied to the River Beas basin, using daily Tropical Rainfall Measuring Mission (TRMM) precipitation and NCEP Climate Forecast System Reanalysis (CFSR) meteorological data to simulate the river regime and crop yields. The Beas is regionally significant as it holds two giant dams, one which annually diverts 4700 Mm3 of water to a nearby basin. We have applied Sequential Uncertainty Fitting Ver. 2 (SUFI-2) to quantify the parameter uncertainty of the stream flow modelling. The model evaluation statistics for Daily River flows at the Jwalamukhi and Pong gauges show good agreement with measured flows (Nash Sutcliffe efficiency of 0.70 and PBIAS of 7.54 %). We then applied the models within a scenario-neutral framework to develop hydrological and crop yield Impact Response Surfaces (IRS) for future changes in annual temperature and precipitation for the region from AR5. Future Q10 and Q90 daily flows indicate amplified 'flash flood' situations and increased low flows, respectively, with increasing temperatures due to increased snowmelt from retreating glaciers. Under existing crop and irrigation management practices, the IRS show decreasing and increasing crop yields for summer (monsoon) and winter (post monsoon) crops, respectively, with rising temperature. Climate change scenario studies shows that, the sensitivity of winter (post monsoon) crop yields to precipitation increases with increasing temperature. The paper will consider the implications of the research for future agricultural water resource management and the potential of adaptation to offset yield losses

  5. Replacing fallow with continuous cropping reduces crop water productivity of semiarid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water supply frequently limits crop yield in semiarid cropping systems; water deficits can restrict yields in drought-affected subhumid regions. In semiarid wheat (Triticum aestivumL.)-based cropping systems, replacing an uncropped fallow period with a crop can increase precipitation use efficiency ...

  6. Improving Biomass Yields: High Biomass, Low Input Dedicated Energy Crops to Enable a Full Scale Bioenergy Industry

    SciTech Connect

    2010-01-01

    Broad Funding Opportunity Announcement Project: Ceres is developing bigger and better grasses for use in biofuels. The bigger the grass yield, the more biomass, and more biomass means more biofuel per acre. Using biotechnology, Ceres is developing grasses that will grow bigger with less fertilizer than current grass varieties. Hardier, higher-yielding grass also requires less land to grow and can be planted in areas where other crops can’t grow instead of in prime agricultural land. Ceres is conducting multi-year trials in Arizona, Texas, Tennessee, and Georgia which have already resulted in grass yields with as much as 50% more biomass than yields from current grass varieties.

  7. Assessing crop yield benefits from in situ rainwater harvesting through contour ridges in semi-arid Zimbabwe

    NASA Astrophysics Data System (ADS)

    Mhizha, A.; Ndiritu, J. G.

    Rainwater harvesting through modified contour ridges known as dead level contours has been practiced in Zimbabwe in the last two decades. Studies have shown marginal soil moisture retention benefits for using this technique while results on crop yield benefits are lacking. This paper presents results from a field study for assessing the impact of dead level contours on soil moisture and crop yield carried out from 2009 to 2011 within the Limpopo River Basin. The experiments were carried out on two study sites; one containing silt loam soil and another containing sandy soil. Three treatments constituting dead level contoured plots, non-contoured plots and plots with the traditional graded contours were used on each site. All the three treatments were planted with a maize crop and managed using conventional farming methods. Planting, weeding and fertiliser application in the three treatments were done at the same time. Crop monitoring was carried out on sub plots measuring 4 m by 4 m established in every treatment. The development of the crop was monitored until harvesting time with data on plant height, leaf moisture and crop yield being collected. An analysis of the data shows that in the site with silt loam soil more soil moisture accumulated after heavy rainfall in dead level contour plots compared to the control (no contours) and graded contour plots (P < 0.05). However the maize crop experienced an insignificantly (P > 0.05) higher yield in the dead level contoured treatment compared to the non-contoured treatment while a significantly (P < 0.05) higher yield was obtained in the dead level contoured treatment when compared with a graded contoured treatment. Different results were obtained from the site with sandy soil where there was no significant difference in soil moisture after a high rainfall event of 60 mm/day between dead level contour plots compared to the control and graded contour plots. The yield from the dead level contoured treatment and that from

  8. The Impact of Changing Snowmelt Timing on Non-Irrigated Crop Yield: A Parametric and Non-Parametric Approach

    NASA Astrophysics Data System (ADS)

    Murray, E. M.; Cobourn, K.; Flores, A. N.; Pierce, J. L.

    2014-12-01

    As climate changes, the final date of spring snowmelt is projected to occur earlier in the year within the western United States. This earlier snowmelt timing may impact crop yield in snow-dominated watersheds by changing the timing of water delivery to agricultural fields. There is considerable uncertainty about how agricultural impacts of snowmelt timing may vary by region, crop-type, and practices like irrigation vs. dryland farming. Establishing the relationship between snowmelt timing and agricultural yield is important for understanding how changes in large-scale climatic indices (like snowmelt date) may be associated with changes in agricultural yield. A better understanding of the influence of changes in snowmelt on non-irrigated crop yield may additionally be extrapolated to better understand how climate change may alter biomass production in non-managed ecosystems. We utilized parametric regression techniques to isolate the magnitude of impact snowmelt timing has had on historical crop yield independently of climate and spatial variables that also impact yield. To do this, we examined the historical relationship between snowmelt timing and non-irrigated wheat and barley yield using a multiple linear regression model to predict yield in several Idaho counties as a function of snowmelt date, climate variables (precipitation and growing degree-days), and spatial differences between counties. We utilized non-parametric techniques to determine where snowmelt timing has positively versus negatively impacted yield. To do this, we developed classification and regression trees to identify spatial controls (e.g. latitude, elevation) on the relationship between snowmelt timing and yield. Most trends suggest a decrease in crop yield with earlier snowmelt, but a significant opposite relationship is observed in some regions of Idaho. An earlier snowmelt date occurring at high latitudes corresponds with higher than average wheat yield. Therefore, Northern Idaho may

  9. MODELING THE POTENTIAL CHANGE IN YIELD AND DISTRIBUTION OF THE EARTH'S CROPS UNDER A WARMED CLIMATE

    EPA Science Inventory

    The large scale distribution of crops is largely determined by climate. e present the results of a climate-crop prediction model based on the U.S. Food & Agriculture Organization crop-suitability approach, implemented in a geographic information system(GIS) environment using seve...

  10. Impact of Winter Cover Crop Biomass Removal on Soil Properties and Cotton Yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, there has been a renewed interest on alternatives sources of energy, especially renewable sources. Numerous materials can be used for this purpose, including crop residues. The use of crop residues would give farmers a new source of income. The use of winter cover crops (WCC) is recommende...

  11. Management factors affecting establishment and yield of bioenergy miscanthus on claypan soil landscapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bioenergy crop Miscanthus x giganteus has been well studied for its establishment and yield in Europe and certain parts of the US Midwest but little has been done to investigate these properties when grown on degraded soils, which are typified as being less productive, and consequently, economically...

  12. Effects of Nitrogen Application Rate on the Yields, Nutritive Value and Silage Fermentation Quality of Whole-crop Wheat

    PubMed Central

    Li, C. J.; Xu, Z. H.; Dong, Z. X.; Shi, S. L.; Zhang, J. G.

    2016-01-01

    Whole-crop wheat (Triticum aestivum L.) as forage has been extensively used in the world. In this study, the effects of N application rates on the yields, nutritive value and silage quality were investigated. The N application rates were 0, 75, 150, 225, and 300 kg/ha. The research results indicated that the dry matter yield of whole-crop wheat increased significantly with increasing N rate up to 150 kg/ha, and then leveled off. The crude protein content and in vitro dry matter digestibility of whole-crop wheat increased significantly with increasing N up to 225 kg/ha, while they no longer increased at N 300 kg/ha. On the contrary, the content of various fibers tended to decrease with the increase of N application. The content of lactic acid, acetic acid and propionic acid in silages increased with the increase of N rate (p<0.05). The ammonia-N content of silages with higher N application rates (≥225 kg/ha) was significantly higher than that with lower N application rates (≤150 kg/ha). Whole-crop wheat applied with high levels of N accumulated more nitrate-N. In conclusion, taking account of yields, nutritive value, silage quality and safety, the optimum N application to whole-crop wheat should be about 150 kg/ha at the present experiment conditions. PMID:26954126

  13. Root length densities of UK wheat and oilseed rape crops with implications for water capture and yield

    PubMed Central

    White, Charlotte A.; Sylvester-Bradley, Roger; Berry, Peter M.

    2015-01-01

    Root length density (RLD) was measured to 1 m depth for 17 commercial crops of winter wheat (Triticum aestivum) and 40 crops of winter oilseed rape [Brassica napus; oilseed rape (OSR)] grown in the UK between 2004 and 2013. Taking the critical RLD (cRLD) for water capture as 1cm cm–3, RLDs appeared inadequate for full water capture on average below a depth of 0.32 m for winter wheat and below 0.45 m for OSR. These depths compare unfavourably (for wheat) with average depths of ‘full capture’ of 0.86 m and 0.48 m, respectively, determined for three wheat crops and one OSR crop studied in the 1970s and 1980s, and treated as references here. A simple model of water uptake and yield indicated that these shortfalls in wheat and OSR rooting compared with the reference data might be associated with shortfalls of up to 3.5 t ha–1 and 1.2 t ha–1, respectively, in grain yields under water-limited conditions, as increasingly occur through climate change. Coupled with decreased summer rainfall, poor rooting of modern arable crops could explain much of the yield stagnation that has been observed on UK farms since the 1990s. Methods of monitoring and improving rooting under commercial conditions are reviewed and discussed. PMID:25750427

  14. Root length densities of UK wheat and oilseed rape crops with implications for water capture and yield.

    PubMed

    White, Charlotte A; Sylvester-Bradley, Roger; Berry, Peter M

    2015-04-01

    Root length density (RLD) was measured to 1 m depth for 17 commercial crops of winter wheat (Triticum aestivum) and 40 crops of winter oilseed rape [Brassica napus; oilseed rape (OSR)] grown in the UK between 2004 and 2013. Taking the critical RLD (cRLD) for water capture as 1cm cm(-3), RLDs appeared inadequate for full water capture on average below a depth of 0.32 m for winter wheat and below 0.45 m for OSR. These depths compare unfavourably (for wheat) with average depths of 'full capture' of 0.86 m and 0.48 m, respectively, determined for three wheat crops and one OSR crop studied in the 1970s and 1980s, and treated as references here. A simple model of water uptake and yield indicated that these shortfalls in wheat and OSR rooting compared with the reference data might be associated with shortfalls of up to 3.5 t ha(-1) and 1.2 t ha(-1), respectively, in grain yields under water-limited conditions, as increasingly occur through climate change. Coupled with decreased summer rainfall, poor rooting of modern arable crops could explain much of the yield stagnation that has been observed on UK farms since the 1990s. Methods of monitoring and improving rooting under commercial conditions are reviewed and discussed. PMID:25750427

  15. Effects of Nitrogen Application Rate on the Yields, Nutritive Value and Silage Fermentation Quality of Whole-crop Wheat.

    PubMed

    Li, C J; Xu, Z H; Dong, Z X; Shi, S L; Zhang, J G

    2016-08-01

    Whole-crop wheat (Triticum aestivum L.) as forage has been extensively used in the world. In this study, the effects of N application rates on the yields, nutritive value and silage quality were investigated. The N application rates were 0, 75, 150, 225, and 300 kg/ha. The research results indicated that the dry matter yield of whole-crop wheat increased significantly with increasing N rate up to 150 kg/ha, and then leveled off. The crude protein content and in vitro dry matter digestibility of whole-crop wheat increased significantly with increasing N up to 225 kg/ha, while they no longer increased at N 300 kg/ha. On the contrary, the content of various fibers tended to decrease with the increase of N application. The content of lactic acid, acetic acid and propionic acid in silages increased with the increase of N rate (p<0.05). The ammonia-N content of silages with higher N application rates (≥225 kg/ha) was significantly higher than that with lower N application rates (≤150 kg/ha). Whole-crop wheat applied with high levels of N accumulated more nitrate-N. In conclusion, taking account of yields, nutritive value, silage quality and safety, the optimum N application to whole-crop wheat should be about 150 kg/ha at the present experiment conditions. PMID:26954126

  16. Can Crop Models Simulate the ENSO Impacts on Regional Corn Yield in U.s. Corn Belt?

    NASA Astrophysics Data System (ADS)

    Niyogi, D. S.; Liu, X.; Andresen, J.; Jain, A. K.; Kumar, A.; Kellner, O.; Elias, A.

    2013-12-01

    In this paper, we seek to answer two questions: 1. Whether climate variability/ ENSO events impact the corn yield in U.S. Corn Belt?; and 2.Can crop models capture these impacts?. First, we evaluated the relationships between ENSO events and regional corn yield in the U.S Corn Belt, by taking data from 18 representative crop reporting districts for a 30 year period (1981-2010). These data were compiled as part of a large multiscale NIFA project titled U2U that aims at making Climate Information Useful to Usable. We clustered the data for different ENSO phases and performed statistical analysis to understand the impacts on corn yield. The detrended observed data indicate that El Niño events have positive impact on corn yields while La Niña events have slightly negative impact. These results are statistically significant at 0.05 level. To investigate whether crop models can capture the impacts of El Niño / La Niña; we compared the yields from three different crop models of varying complexity (Hybrid Maize; DSSAT; and ISAM) with default/ common agronomic and onsite meteorological input. Simulated yields show similar pattern as seen in the observed data: higher yield for El Niño years, and lower yields for the La Niña years. However, we also found MAE (Mean absolute error) of simulations in El Niño years are higher than for the La Niña years and Neutral years. To understand whether the performance can be enhanced by providing regional climatology, hydroclimatological, or agronomic information - we conducted additional experiments with the Hybrid Maize models involving- (i) use of onsite versus regional reanalysis data - the hypothesis being that even if the onsite data may have limited ENSO signature; the reanalysis data will have a much stronger ENSO feedback embedded within; (ii) use of actual planting date versus the default value used in the crop models - to understand if the year to year agronomic practice might influence or improve the response to capture

  17. Drought-related vulnerability and risk assessment of groundwater in Belgium: estimation of the groundwater recharge and crop yield vulnerability with the B-CGMS

    NASA Astrophysics Data System (ADS)

    Jacquemin, Ingrid; Verbeiren, Boud; Vanderhaegen, Sven; Canters, Frank; Vermeiren, Karolien; Engelen, Guy; Huysmans, Marijke; Batelaan, Okke; Tychon, Bernard

    2016-04-01

    Due to common belief that regions under temperate climate are not affected by (meteorological and groundwater) drought, these events and their impacts remain poorly studied: in the GroWaDRISK, we propose to take stock of this question. We aim at providing a better understanding of the influencing factors (land use and land cover changes, water demand and climate) and the drought-related impacts on the environment, water supply and agriculture. The study area is located in the North-East of Belgium, corresponding approximatively to the Dijle and Demer catchments. To establish an overview of the groundwater situation, we assess the system input: the recharge. To achieve this goal, two models, B-CGMS and WetSpass are used to evaluate the recharge, respectively, over agricultural land and over the remaining areas, as a function of climate and for various land uses and land covers. B-CGMS, which is an adapted version for Belgium of the European Crop Growth Monitoring System, is used for assessing water recharge at a daily timestep and under different agricultural lands: arable land (winter wheat, maize...), orchards, horticulture and floriculture and for grassland. B-CGMS is designed to foresee crop yield and obviously it studies the impact of drought on crop yield and raises issues for the potential need of irrigation. For both yields and water requirements, the model proposes a potential mode, driven by temperature and solar radiation, and a water-limited mode for which water availability can limit crop growth. By this way, we can identify where and when water consumption and yield are not optimal, in addition to the Crop Water Stress Index. This index is calculated for a given crop, as the number of days affected by water stress during the growth sensitive period. Both recharge and crop yield are assessed for the current situation (1980 - 2012), taking into account the changing land use/land cover, in terms of areas and localization of the agricultural land and where

  18. Using spectral distance, spectral angle, and plant abundance derived from hyperspectral imagery to characterize crop yield variation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetation indices (VIs) derived from remote sensing imagery are commonly used to quantify crop growth and yield variations. As hyperspectral imagery is becoming more available, the number of possible VIs that can be calculated is overwhelmingly large. The objectives of this study were to examine sp...

  19. 7 CFR 1412.34 - Submitting production evidence for establishing direct payment yields for oilseeds and pulse crops.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Submitting production evidence for establishing direct payment yields for oilseeds and pulse crops. 1412.34 Section 1412.34 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DIRECT...

  20. Long-range climate impacts on crop yield and the implications of enacting global carbon mitigation policies

    EPA Science Inventory

    Research on climate impacts and agriculture over the past two decades has applied simulation models at a range of scales and future climate scenarios, finding that crop growth and yield responds to changing climate conditions, and that the impacts are regional and highly depende...

  1. Yields of Corn Silage Fertilized with Manure and Grown with Legume or Non-legume Companion Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In addition to reducing nitrate and soil losses, cover crops and living mulches could enhance corn silage yields. In a four-year study in southern Wisconsin, no-till corn was grown with herbicide-suppressed Kura-clover or with June-interseeded red clover followed by one year of clover production. Th...

  2. Global crop yield reductions due to surface ozone exposure: 2. Year 2030 potential crop production losses and economic damage under two scenarios of O 3 pollution

    NASA Astrophysics Data System (ADS)

    Avnery, Shiri; Mauzerall, Denise L.; Liu, Junfeng; Horowitz, Larry W.

    2011-04-01

    We examine the potential global risk of increasing surface ozone (O 3) exposure to three key staple crops (soybean, maize, and wheat) in the near future (year 2030) according to two trajectories of O 3 pollution: the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC SRES) A2 and B1 storylines, which represent upper- and lower-boundary projections, respectively, of most O 3 precursor emissions in 2030. We use simulated hourly O 3 concentrations from the Model for Ozone and Related Chemical Tracers version 2.4 (MOZART-2), satellite-derived datasets of agricultural production, and field-based concentration:response relationships to calculate crop yield reductions resulting from O 3 exposure. We then calculate the associated crop production losses and their economic value. We compare our results to the estimated impact of O 3 on global agriculture in the year 2000, which we assessed in our companion paper [Avnery et al., 2011]. In the A2 scenario we find global year 2030 yield loss of wheat due to O 3 exposure ranges from 5.4 to 26% (a further reduction in yield of +1.5-10% from year 2000 values), 15-19% for soybean (reduction of +0.9-11%), and 4.4-8.7% for maize (reduction of +2.1-3.2%) depending on the metric used, with total global agricultural losses worth 17-35 billion USD 2000 annually (an increase of +6-17 billion in losses from 2000). Under the B1 scenario, we project less severe but still substantial reductions in yields in 2030: 4.0-17% for wheat (a further decrease in yield of +0.1-1.8% from 2000), 9.5-15% for soybean (decrease of +0.7-1.0%), and 2.5-6.0% for maize (decrease of + 0.3-0.5%), with total losses worth 12-21 billion annually (an increase of +1-3 billion in losses from 2000). Because our analysis uses crop data from the year 2000, which likely underestimates agricultural production in 2030 due to the need to feed a population increasing from approximately 6 to 8 billion people between 2000 and 2030, our

  3. A data-oriented semi-process model for evaluating the yields of major crops at global scale (PRYSBI-2)

    NASA Astrophysics Data System (ADS)

    Sakurai, G.; Iizumi, T.; Yokozawa, M.

    2013-12-01

    Demand for major cereal crops will double by 2050 compared to the amount in 2005 due to the population growth, dietary change, and increase in biofuel use. This requires substantial efforts to increase crop yields under changing climate, water resources, and land use. In order to explore possible paths to meet the supply target, global crop modeling is a useful approach. To that end, we developed a process-based large-area crop model (called PRYSBIE-2) for major crops, including soybean. This model consisted of the enzyme kinetics model for photosynthetic carbon assimilation and soil water balance model from SWAT. The parameter values on water stress, nitrogen stress were calibrated over global croplands from one grid cell to another (1.125° in latitude and longitude) using Markov Chain Monte Carlo (MCMC) methods. The historical yield data collected from major crop-producing countries on a state, county, or prefecture scale were used as the calibration data. Then we obtained the model parameter sets that can give high correlation coefficients between the historical and estimated yield time series for the period 1980-2006. We analyzed the impacts on soybean yields in the three top soybean-producing countries (the USA, China, and Brazil) associated with the changes in climate and CO2 during the period 1980-2006, using the model. We found that, given the simulated yields and reported harvested areas, the estimated average net benefit from the CO2 fertilization effect (with one standard deviation) in the USA, Brazil, and China in the years was 42.70×32.52 Mt, 35.30×28.55 Mt, and 12.52×15.11 Mt, respectively. Results suggest that the CO2-induced increases in soybean yields in the USA and China likely offset a part of the negative impacts on yields due to the historical temperature rise. In contrast, the net effect of the past change in climate and CO2 in Brazil appeared to be positive. This study demonstrates a quantitative estimation of the impacts of the changes

  4. Effects of different on-farm management on yield and water use efficiency of Potato crop cultivated in semiarid environments under subsurface drip irrigation

    NASA Astrophysics Data System (ADS)

    Ghazouani, Hiba; Provenzano, Giuseppe; Rallo, Giovanni; Mguidiche, Amel; Douh, Boutheina; Boujelben, Abdelhamid

    2016-04-01

    In Tunisia the amount of water for irrigated agriculture is higher than about 80% of the total resource.The increasing population and the rising food demand, associated to the negative effects of climate change,make it crucial to adopt strategies aiming to improve water use efficiency (WUE). Moreover, the absence of an effective public policy for water management amplifies the imbalance between water supply and its demand. Despite improved irrigation technologies can enhance the efficiency of water distribution systems, to achieve environmental goals it is also necessaryto identify on-farm management strategies accounting for actual crop water requirement. The main objective of the paper was to assess the effects of different on-farm managementstrategies (irrigation scheduling and planting date) on yield and water use efficiency of Potato crop (Solanumtuberosum L.) irrigated with a subsurface drip system, under the semi-arid climate of central Tunisia. Experiments were carried out during three growing seasons (2012, 2014 and 2015) at the High Agronomic Institute of ChottMariem in Sousse, by considering different planting dates and irrigation depths, the latter scheduled according to the climate observed during the season. All the considered treatments received the same pesticide and fertilizer management. Experiments evidenced that the climatic variability characterizing the examined seasons (photoperiod, solar radiation and average temperature) affects considerably the crop phenological stages, and the late sowing shortens the crop cycle.It has also been demonstrated that Leaf Area Index (LAI) and crop yield resulted relatively higher for those treatments receiving larger amounts of seasonal water. Crop yield varied between 16.3 t/ha and 39.1 t/ha, with a trend linearly related to the ratio between the seasonal amount of water supplied (Irrigation, I and Precipitation, P) and the maximum crop evapotranspiration (ETm). The maximum crop yield was in particular

  5. Regional-scale yield simulations using crop and climate models: assessing uncertainties, sensitivity to temperature and adaptation options

    NASA Astrophysics Data System (ADS)

    Challinor, A. J.

    2010-12-01

    Recent progress in assessing the impacts of climate variability and change on crops using multiple regional-scale simulations of crop and climate (i.e. ensembles) is presented. Simulations for India and China used perturbed responses to elevated carbon dioxide constrained using observations from FACE studies and controlled environments. Simulations with crop parameter sets representing existing and potential future adapted varieties were also carried out. The results for India are compared to sensitivity tests on two other crop models. For China, a parallel approach used socio-economic data to account for autonomous farmer adaptation. Results for the USA analysed cardinal temperatures under a range of local warming scenarios for 2711 varieties of spring wheat. The results are as follows: 1. Quantifying and reducing uncertainty. The relative contribution of uncertainty in crop and climate simulation to the total uncertainty in projected yield changes is examined. The observational constraints from FACE and controlled environment studies are shown to be the likely critical factor in maintaining relatively low crop parameter uncertainty. Without these constraints, crop simulation uncertainty in a doubled CO2 environment would likely be greater than uncertainty in simulating climate. However, consensus across crop models in India varied across different biophysical processes. 2. The response of yield to changes in local mean temperature was examined and compared to that found in the literature. No consistent response to temperature change was found across studies. 3. Implications for adaptation. China. The simulations of spring wheat in China show the relative importance of tolerance to water and heat stress in avoiding future crop failures. The greatest potential for reducing the number of harvests less than one standard deviation below the baseline mean yield value comes from alleviating water stress; the greatest potential for reducing harvests less than two

  6. Impact of vetch cover crop on runoff, soil loss, soil chemical properties and yield of chickpea in North Gondar, Ethiopia

    NASA Astrophysics Data System (ADS)

    Demelash, Nigus; Klik, Andreas; Holzmann, Hubert; Ziadat, Feras; Strohmeier, Stefan; Bayu, Wondimu; Zucca, Claudio; Abera, Atikilt

    2016-04-01

    Cover crops improve the sustainability and quality of both natural system and agro ecosystem. In Gumara-Maksegnit watershed which is located in Lake Tana basin, farmers usually use fallow during the rainy season for the preceding chickpea production system. The fallowing period can lead to soil erosion and nutrient losses. A field experiment was conducted during growing seasons 2014 and 2015 to evaluate the effect of cover crops on runoff, soil loss, soil chemical properties and yield of chickpea in North Gondar, Ethiopia. The plot experiment contained four treatments arranged in Randomized Complete Block Design with three replications: 1) Control plot (Farmers' practice: fallowing- without cover crop), 2) Chickpea planted with Di-ammonium phosphate (DAP) fertilizer with 46 k ha-1 P2O5 and 23 k ha-1 nitrogen after harvesting vetch cover crop, 3) Chick pea planted with vetch cover crop incorporated with the soil as green manure without fertilizer, 4) Chick pea planted with vetch cover crop and incorporated with the soil as green manure and with 23 k ha-1 P2O5 and 12.5 k ha-1 nitrogen. Each plot with an area of 36 m² was equipped with a runoff monitoring system. Vetch (Vicia sativa L.) was planted as cover crop at the onset of the rain in June and used as green manure. The results of the experiment showed statistically significant (P < 0.05) differences on the number of pods per plant, above ground biomass and grain yield of chick pea. However, there was no statistically significant difference (P > 0.05) on average plant height, average number of branches and hundred seed weight. Similarly, the results indicated that cover crop has a clear impact on runoff volume and sediment loss. Plots with vetch cover crop reduce the average runoff by 65% and the average soil loss decreased from 15.7 in the bare land plot to 8.6 t ha-1 with plots covered by vetch. In general, this result reveales that the cover crops, especially vetch, can be used to improve chickpea grain yield

  7. Accelerating the domestication of a bioenergy crop: identifying and modelling morphological targets for sustainable yield increase in Miscanthus

    PubMed Central

    Farrar, Kerrie

    2013-01-01

    To accelerate domestication of Miscanthus, an important energy crop, 244 replicated genotypes, including two different species and their hybrids, were analysed for morphological traits and biomass yield over three growing seasons following an establishment phase of 2 years in the largest Miscanthus diversity trial described to date. Stem and leaf traits were selected that contributed both directly and indirectly to total harvested biomass yield, and there was variation in all traits measured. Morphological diversity within the population was correlated with dry matter yield (DMY) both as individual traits and in combination, in order to determine the respective contributions of the traits to biomass accumulation and to identify breeding targets for yield improvement. Predictive morphometric analysis was possible at year 3 within Miscanthus sinensis genotypes but not between M. sinensis, Miscanthus sacchariflorus, and interspecific hybrids. Yield is a complex trait, and no single simple trait explained more than 33% of DMY, which varied from 1 to 5297g among genotypes within this trial. Associating simple traits increased the power of the morphological data to predict yield to 60%. Trait variety, in combination, enabled multiple ideotypes, thereby increasing the potential diversity of the crop for multiple growth locations and end uses. Both triploids and interspecific hybrids produced the highest mature yields, indicating that there is significant heterosis to be exploited within Miscanthus that might be overlooked in early selection screens within years 1–3. The potential for optimizing biomass yield by selecting on the basis of morphology is discussed. PMID:24064927

  8. Airborne and ground-based remote sensing for the estimation of evapotranspiration and yield of bean, potato, and sugar beet crops

    NASA Astrophysics Data System (ADS)

    Jayanthi, Harikishan

    The focus of this research was two-fold: (1) extend the reflectance-based crop coefficient approach to non-grain (potato and sugar beet), and vegetable crops (bean), and (2) develop vegetation index (VI)-yield statistical models for potato and sugar beet crops using high-resolution aerial multispectral imagery. Extensive crop biophysical sampling (leaf area index and aboveground dry biomass sampling) and canopy reflectance measurements formed the backbone of developing of canopy reflectance-based crop coefficients for bean, potato, and sugar beet crops in this study. Reflectance-based crop coefficient equations were developed for the study crops cultivated in Kimberly, Idaho, and subsequently used in water availability simulations in the plant root zone during 1998 and 1999 seasons. The simulated soil water profiles were compared with independent measurements of actual soil water profiles in the crop root zone in selected fields. It is concluded that the canopy reflectance-based crop coefficient technique can be successfully extended to non-grain crops as well. While the traditional basal crop coefficients generally expect uniform growth in a region the reflectance-based crop coefficients represent the actual crop growth pattern (in less than ideal water availability conditions) in individual fields. Literature on crop canopy interactions with sunlight states that there is a definite correspondence between leaf area index progression in the season and the final yield. In case of crops like potato and sugar beet, the yield is influenced not only on how early and how quickly the crop establishes its canopy but also on how long the plant stands on the ground in a healthy state. The integrated area under the crop growth curve has shown excellent correlations with hand-dug samples of potato and sugar beet crops in this research. Soil adjusted vegetation index-yield models were developed, and validated using multispectral aerial imagery. Estimated yield images were

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

    NASA Astrophysics Data System (ADS)

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

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

  10. Assimilation of Downscaled SMOS Soil Moisture for Quantifying Drought Impacts on Crop Yield in Agricultural Regions in Brazil

    NASA Astrophysics Data System (ADS)

    Chakrabarti, S.; Bongiovanni, T. E.; Judge, J.; Principe, J. C.; Fraisse, C.

    2013-12-01

    Reliable soil moisture (SM) information in the root zone (RZSM) is critical for quantification of agricultural drought impacts on crop yields and for recommending management and adaptation strategies for crop management, commodity trading and food security.The recently launched European Space Agency-Soil Moisture and Ocean Salinity (ESA-SMOS) and the near-future National Aeronautics and Space Administration-Soil Moisture Active Passive (NASA-SMAP) missions provide SM at unprecedented spatial resolutions of 10-25 km, but these resolutions are still too coarse for agricultural applications in heterogeneous landscapes, making downscaling a necessity. This downscaled near-surface SM can be merged with crop growth models in a data assimilation framework to provide optimal estimates of RZSM and crop yield. The objectives of the study include: 1) to implement a novel downscalingalgorithm based on the Information theoretical learning principlesto downscale SMOS soil moisture at 25 km to 1km in the Brazilian La Plata Basin region and2) to assimilate the 1km-soil moisture in the crop model for a normal and a drought year to understand the impact on crop yield. In this study, a novel downscaling algorithm based on the Principle of Relevant Information (PRI) was applied to in-situ and remotely sensed precipitation, SM, land surface temperature and leaf area index in the Brazilian Lower La Plata region in South America. An Ensemble Kalman Filter (EnKF) based assimilation algorithm was used to assimilate the downscaled soil moisture to update both states and parameters. The downscaled soil moisture for two growing seasons in2010-2011 and 2011-2012 was assimilated into the Decision Support System for Agrotechnology Transfer (DSSAT) Cropping System Model over 161 km2 rain-fed region in the Brazilian LPB regionto improve the estimates of soybean yield. The first season experienced normal precipitation, while the second season was impacted by drought. Assimilation improved yield

  11. Microbial community composition as affected by dryland cropping systems and tillage in a semiarid sandy soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated microbial communities of soil (0-10 cm) as affected by dryland cropping systems under different tillage practices after 5 years. The soil is an Olton sandy loam (Fine, mixed, superactive, thermic Aridic Paleustolls) with an average of 16.4% clay, 67.6% sand and 0.65 g kg-1 of O...

  12. Tree growth and management in Ugandan agroforestry systems: effects of root pruning on tree growth and crop yield.

    PubMed

    Wajja-Musukwe, Tellie-Nelson; Wilson, Julia; Sprent, Janet I; Ong, Chin K; Deans, J Douglas; Okorio, John

    2008-02-01

    Tree root pruning is a potential tool for managing belowground competition when trees and crops are grown together in agroforestry systems. We investigated the effects of tree root pruning on shoot growth and root distribution of Alnus acuminata (H.B. & K.), Casuarina equisetifolia L., Grevillea robusta A. Cunn. ex R. Br., Maesopsis eminii Engl. and Markhamia lutea (Benth.) K. Schum. and on yield of adjacent crops in sub-humid Uganda. The trees were 3 years old at the commencement of the study, and most species were competing strongly with crops. Tree roots were pruned 41 months after planting by cutting and back-filling a trench to a depth of 0.3 m, at a distance of 0.3 m from the trees, on one side of the tree row. The trench was reopened and roots recut at 50 and 62 months after planting. We assessed the effects on tree growth and root distribution over a 3 year period, and crop yield after the third root pruning at 62 months. Overall, root pruning had only a slight effect on aboveground tree growth: height growth was unaffected and diameter growth was reduced by only 4%. A substantial amount of root regrowth was observed by 11 months after pruning. Tree species varied in the number and distribution of roots, and C. equisetifolia and M. lutea had considerably more roots per unit of trunk volume than the other species, especially in the surface soil layers. Casuarina equisetifolia and M. eminii were the tree species most competitive with crops and G. robusta and M. lutea the least competitive. Crop yield data provided strong evidence of the redistribution of root activity following root pruning, with competition increasing on the unpruned side of tree rows. Thus, one-sided root pruning will be useful in only a few circumstances. PMID:18055434

  13. Assessing future drought impacts on yields based on historical irrigation reaction to drought for four major crops in Kansas.

    PubMed

    Zhang, Tianyi; Lin, Xiaomao

    2016-04-15

    Evaluation of how historical irrigation reactions can adapt to future drought is indispensable to irrigation policy, however, such reactions are poorly quantified. In this paper, county-level irrigation data for maize, soybean, grain sorghum, and wheat crops in Kansas were compiled. Statistical models were developed to quantify changes of irrigation and yields in response to drought for each crop. These were then used to evaluate the ability of current irrigation to cope with future drought impacts on each crop based on an ensemble Palmer Drought Severity Index (PDSI) prediction under the Representative Concentration Pathways 4.5 scenario. Results indicate that irrigation in response to drought varies by crop; approximately 10 to 13% additional irrigation was applied when PDSI was reduced by one unit for maize, soybean, and grain sorghum. However, the irrigation reaction for wheat exhibits a large uncertainty, indicating a weaker irrigation reaction. Analysis of future climate conditions indicates that maize, soybean, and grain sorghum yields would decrease 2.2-12.4% at the state level despite additional irrigation application induced by drought (which was expected to increase 5.1-19.0%), suggesting that future drought will exceed the range that historical irrigation reactions can adapt to. In contrast, a lower reduction (-0.99 to -0.63%) was estimated for wheat yields because wetter climate was projected in the central section of the study area. Expanding wheat areas may be helpful in avoiding future drought risks for Kansas agriculture. PMID:26851757

  14. Drainage and leaching dynamics in a cropped hummocky soil landscape with erosion-affected pedogenesis

    NASA Astrophysics Data System (ADS)

    Gerke, Horst H.; Rieckh, Helene; Sommer, Michael

    2016-04-01

    Hummocky soil landscapes are characterized by 3D spatial patterns of soil types that result from erosion-affected pedogenesis. Due to tillage and water erosion, truncated profiles have been formed at steep and mid slopes and colluvial soils at hollows. Pedogenetic variations in soil horizons at the different hillslope positions suggested feedback effects between erosion affected soil properties, the water balances, and the crop growth and leaching rates. Water balance simulations compared uniform with hillslope position-specific crop and root growths for soils at plateau, flat mid slope, steep slope, and hollow using the Hydrus-1D program. The boundary condition data were monitored at the CarboZALF-D experimental field site, which was cropped with perennial lucerne (Medicago sativa L.) in 2013 and 2014. Crop and root growth was assumed proportional to observed leaf area index (LAI). Fluxes of dissolved organic and inorganic carbon (DOC, DIC) were obtained from simulated water fluxes and measured DOC and DIC concentrations. For the colluvic soil, the predominately upward flow led to a net input in DIC and DOC. For the truncated soils at steep slopes, a reduced crop growth caused an relative increase in drainage, suggesting an accelerated leaching, which in the long term could accelerate the soil development and more soil variations along eroding hillslopes in arable soil landscapes.

  15. Impact of large-scale climate variability and change on crop yields in Africa: An observational assessment

    NASA Astrophysics Data System (ADS)

    Smoliak, B. V.; Po-Chedley, S.; Cullen, A. C.

    2011-12-01

    Assessments of the relationships between climate and agricultural production have progressed from opposite ends of the spatio-temporal spectrum. While studies of global-scale climate-yield relationships have provided estimates of the impact of multi-decadal trends in temperature and precipitation on recent production, studies of local weather impacts on yield have demonstrated the influence of temperature and precipitation variability on plant physiology, particularly with respect to the duration and timing of extremes. At intermediate spatial and temporal scales, somewhat of a gap in understanding exists. Our investigation contributes to better understanding climate-yield relationships at intermediate scales by assessing the impact of climate variability on crop yields at the country to continent scale on interannual to interdecadal timescales. Toward this end, we employ historical climatic data and reported cereal crop yields from the African continent, 1961 to 2009, in conjunction with principal component regression and partial least squares regression. Our results show that a discrete set of spatial patterns of climate variability account for up to half of the year-to-year variability in crop yields over portions of Africa. The impact of this climate variability is particularly strong in Sub-Saharan Africa, where large or prolonged deficits in yields can result in food shortages. The fundamental patterns of variability used to explain yield fluctuations are based on temperature and precipitation, chosen due to their influence on plant physiology; however, the time-varying behavior of the patterns may also be linked to coherent large-scale climate variability through regressions with sea surface temperature, sea level pressure and low-level wind fields. Results are distilled in terms of five UN designated geographic regions of Africa. Implications for short-term food security and future climate change are discussed.

  16. Rice Crop Monitoring and Yield Estimation Through Cosmo Skymed and TerraSAR-X: A SAR-Based Experience in India

    NASA Astrophysics Data System (ADS)

    Pazhanivelan, S.; Kannan, P.; Nirmala Mary, P. Christy; Subramanian, E.; Jeyaraman, S.; Nelson, A.; Setiyono, T.; Holecz, F.; Barbieri, M.; Yadav, M.

    2015-04-01

    Rice is the most important cereal crop governing food security in Asia. Reliable and regular information on the area under rice production is the basis of policy decisions related to imports, exports and prices which directly affect food security. Recent and planned launches of SAR sensors coupled with automated processing can provide sustainable solutions to the challenges on mapping and monitoring rice systems. High resolution (3m) Synthetic Aperture Radar (SAR) imageries were used to map and monitor rice growing areas in selected three sites in TamilNadu, India to determine rice cropping extent, track rice growth and estimate yields. A simple, robust, rule-based classification for mapping rice area with multi-temporal, X-band, HH polarized SAR imagery from COSMO Skymed and TerraSAR X and site specific parameters were used. The robustness of the approach is demonstrated on a very large dataset involving 30 images across 3 footprints obtained during 2013-14. A total of 318 in-season site visits were conducted across 60 monitoring locations for rice classification and 432 field observations were made for accuracy assessment. Rice area and Start of Season (SoS) maps were generated with classification accuracies ranging from 87- 92 per cent. Using ORYZA2000, a weather driven process based crop growth simulation model; yield estimates were made with the inclusion of rice crop parameters derived from the remote sensing products viz., seasonal rice area, SoS and backscatter time series. Yield Simulation accuracy levels of 87 per cent at district level and 85- 96 per cent at block level demonstrated the suitability of remote sensing products for policy decisions ensuring food security and reducing vulnerability of farmers in India.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  18. Crop Diversification and Management System Influence Yield and Weeds in the Northern Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Available water, depleted soil quality, and weed competition are major constraints to dryland crop production in the northern Great Plains. We initiated a trial in 2004 comparing four crop rotations, with each rotational component in a two-by-two matrix of tillage (conventional vs. zero tillage) an...

  19. Estimated Yield of Some Alternative Crops Under Varying Irrigation in Northeast Colorado

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much of the irrigated acres in northeastern Colorado are devoted to corn grain production. Diversifying irrigated agricultural production in this region could result in water savings if alternative crops were grown that have lower water requirements than corn. Making such crop choice decisions initi...

  20. Site-Specific Compaction, Soil Physical Property, and Crop Yield Relationships for Claypan Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil compaction is a concern in crop production and environmental protection. Compaction is most often quantified in the field, albeit indirectly, using cone penetrometer measurements of soil strength. The objective of this research was to relate soil compaction to soil physical properties and crop ...

  1. Yields in stripper header vs conventional header in dryland cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Differences in crop residue quality can impact the amount of soil water storage in semi-arid no-till systems of the West Central Great Plains. Using a stripper header as opposed to a conventional-reel type header to harvest small grains impacts the quality of the crop residue left in the field. Pr...

  2. ALTERNATIVE OZONE DOSE METRICS TO CHARACTERIZE OZONE IMPACT ON CROP YIELD LOSS (JOURNAL VERSION)

    EPA Science Inventory

    Previous studies of the National Crop Loss Assessment Network (NCLAN) relating the impact of ozone (O3) on agricultural crops have used the seasonal arithmetic average of O3 for either a 7- or 12-h daily period as the measure of dose in the dose response relationships. The study ...

  3. RELATIONSHIP OF SOIL PROFILE STRENGTH AND APPARENT SOIL ELECTRICAL CONDUCTIVITY TO CROP YIELD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding characteristics of claypan soils has long been an issue for researchers and farmers because the high-clay subsoil has a pronounced effect on grain crop productivity. The claypan restricts water infiltration and storage within the crop root zone, but these effects are not uniform within...

  4. Assessment of crop yield losses in Punjab and Haryana using 2 years of continuous in situ ozone measurements

    NASA Astrophysics Data System (ADS)

    Sinha, B.; Singh Sangwan, K.; Maurya, Y.; Kumar, V.; Sarkar, C.; Chandra, B. P.; Sinha, V.

    2015-08-01

    In this study we use a high-quality data set of in situ ozone measurements at a suburban site called Mohali in the state of Punjab to estimate ozone-related crop yield losses for wheat, rice, cotton and maize for Punjab and the neighbouring state Haryana for the years 2011-2013. We intercompare crop yield loss estimates according to different exposure metrics, such as AOT40 (accumulated ozone exposure over a threshold of 40) and M7 (mean 7-hour ozone mixing ratio from 09:00 to 15:59), for the two major crop growing seasons of kharif (June-October) and rabi (November-April) and establish a new crop-yield-exposure relationship for southern Asian wheat, maize and rice cultivars. These are a factor of 2 more sensitive to ozone-induced crop yield losses compared to their European and American counterparts. Relative yield losses based on the AOT40 metrics ranged from 27 to 41 % for wheat, 21 to 26 % for rice, 3 to 5 % for maize and 47 to 58 % for cotton. Crop production losses for wheat amounted to 20.8 ± 10.4 million t in the fiscal year of 2012-2013 and 10.3 ± 4.7 million t in the fiscal year of 2013-2014 for Punjab and Haryana taken together. Crop production losses for rice totalled 5.4 ± 1.2 million t in the fiscal year of 2012-2013 and 3.2 ± 0.8 million t in the year 2013-2014 for Punjab and Haryana taken together. The Indian National Food Security Ordinance entitles ~ 820 million of India's poor to purchase about 60 kg of rice or wheat per person annually at subsidized rates. The scheme requires 27.6 Mt of wheat and 33.6 Mt of rice per year. The mitigation of ozone-related crop production losses in Punjab and Haryana alone could provide > 50 % of the wheat and ~ 10 % of the rice required for the scheme. The total economic cost losses in Punjab and Haryana amounted to USD 6.5 ± 2.2 billion in the fiscal year of 2012-2013 and USD 3.7 ± 1.2 billion in the fiscal year of 2013-2014. This economic loss estimate represents a very conservative lower limit based on

  5. Usability of NASA Satellite Imagery-Based Daily Solar Radiation for Crop Yield Simulation and Management Decisions

    NASA Astrophysics Data System (ADS)

    Yang, H.; Cassman, K. G.; Stackhouse, P. W.; Hoell, J. M.

    2007-12-01

    We tested the usability of NASA satellite imagery-based daily solar radiation for farm-specific crop yield simulation and management decisions using the Hybrid-Maize model (www.hybridmaize.unl.edu). Solar radiation is one of the key inputs for crop yield simulation. Farm-specific crop management decisions using simulation models require long-term (i.e., 20 years or longer) daily local weather data including solar radiation for assessing crop yield potential and its variation, optimizing crop planting date, and predicting crop yield in a real time mode. Weather stations that record daily solar radiation have sparse coverage and many of them have record shorter than 15 years. Based on satellite imagery and other remote sensed information, NASA has provided estimates of daily climatic data including solar radiation at a resolution of 1 degree grid over the earth surface from 1983 to 2005. NASA is currently continuing to update the database and has plans to provide near real-time data in the future. This database, which is free to the public at http://power.larc.nasa.gov, is a potential surrogate for ground- measured climatic data for farm-specific crop yield simulation and management decisions. In this report, we quantified (1) the similarities between NASA daily solar radiation and ground-measured data atr 20 US sites and four international sites, and (2) the accuracy and precision of simulated corn yield potential and its variability using NASA solar radiation coupled with other weather data from ground measurements. The 20 US sites are in the western Corn Belt, including Iowa, South Dakota, Nebraska, and Kansas. The four international sites are Los Banos in the Philippines, Beijing in China, Cali in Columbia, and Ibatan in Nigeria. Those sites were selected because of their high quality weather record and long duration (more than 20 years on average). We found that NASA solar radiation was highly significantly correlated (mean r2 =0.88**) with the ground

  6. Comments on "Global crop yield reductions due to surface ozone exposure: 1. Year 2000 crop production losses and economic damage" and "Global crop yield reductions due to surface ozone exposure: 2. Year 2030 potential crop production losses and economic damage under two scenarios of O3 pollution" by Shiri Avnery, Denise L. Mauzerall, Junfeng Liu, Lary W. Horowitz [Atmospheric Environment 45, 2284-2296 and 2297-2309.

    NASA Astrophysics Data System (ADS)

    Nawahda, Amin

    2013-06-01

    The Authors (Avnery et al., 2011a,b) estimated the relative yield losses of wheat crop in China in 2000 and 2030 to be 15%-20% and 25%-30%, respectively. And the relative yield losses of soybean crop in China in 2000 and 2030 to be 20%-25% and 30%-45%, respectively. These findings do not agree with the information that shows the relative yield losses of wheat crop should be greater than those of soybean crop in China. Additionally, do not agree with the findings of previous studies.

  7. Light- and water-use efficiency model synergy: a revised look at crop yield estimation for agricultural decision-making

    NASA Astrophysics Data System (ADS)

    Marshall, M.; Tu, K. P.

    2015-12-01

    Large-area crop yield models (LACMs) are commonly employed to address climate-driven changes in crop yield and inform policy makers concerned with climate change adaptation. Production efficiency models (PEMs), a class of LACMs that rely on the conservative response of carbon assimilation to incoming solar radiation absorbed by a crop contingent on environmental conditions, have increasingly been used over large areas with remote sensing spectral information to improve the spatial resolution of crop yield estimates and address important data gaps. Here, we present a new PEM that combines model principles from the remote sensing-based crop yield and evapotranspiration (ET) model literature. One of the major limitations of PEMs is that they are evaluated using data restricted in both space and time. To overcome this obstacle, we first validated the model using 2009-2014 eddy covariance flux tower Gross Primary Production data in a rice field in the Central Valley of California- a critical agro-ecosystem of the United States. This evaluation yielded a Willmot's D and mean absolute error of 0.81 and 5.24 g CO2/d, respectively, using CO2, leaf area, temperature, and moisture constraints from the MOD16 ET model, Priestley-Taylor ET model, and the Global Production Efficiency Model (GLOPEM). A Monte Carlo simulation revealed that the model was most sensitive to the Enhanced Vegetation Index (EVI) input, followed by Photosynthetically Active Radiation, vapor pressure deficit, and air temperature. The model will now be evaluated using 30 x 30m (Landsat resolution) biomass transects developed in 2011 and 2012 from spectroradiometric and other non-destructive in situ metrics for several cotton, maize, and rice fields across the Central Valley. Finally, the model will be driven by Daymet and MODIS data over the entire State of California and compared with county-level crop yield statistics. It is anticipated that the new model will facilitate agro-climatic decision-making in

  8. Simulation of nitrous oxide effluxes, crop yields and soil physical properties using the LandscapeDNDC model in managed ecosystem

    NASA Astrophysics Data System (ADS)

    Nyckowiak, Jedrzej; Lesny, Jacek; Haas, Edwin; Juszczak, Radoslaw; Kiese, Ralf; Butterbach-Bahl, Klaus; Olejnik, Janusz

    2014-05-01

    Modeling of nitrous oxide emissions from soil is very complex. Many different biological and chemical processes take place in soils which determine the amount of emitted nitrous oxide. Additionaly, biogeochemical models contain many detailed factors which may determine fluxes and other simulated variables. We used the LandscapeDNDC model in order to simulate N2O emissions, crop yields and soil physical properties from mineral cultivated soils in Poland. Nitrous oxide emissions from soils were modeled for fields with winter wheat, winter rye, spring barley, triticale, potatoes and alfalfa crops. Simulations were carried out for the plots of the Brody arable experimental station of Poznan University of Life Science in western Poland and covered the period 2003 - 2012. The model accuracy and its efficiency was determined by comparing simulations result with measurements of nitrous oxide emissions (measured with static chambers) from about 40 field campaigns. N2O emissions are strongly dependent on temperature and soil water content, hence we compared also simulated soil temperature at 10cm depth and soil water content at the same depth with the daily measured values of these driving variables. We compared also simulated yield quantities for each individual experimental plots with yield quantities which were measured in the period 2003-2012. We conclude that the LandscapeDNDC model is capable to simulate soil N2O emissions, crop yields and physical properties of soil with satisfactorily good accuracy and efficiency.

  9. [Effects of rape cropping in summer fallow period on dryland soil moisture content and winter wheat yield].

    PubMed

    Zhao, Gang; Fan, Ting-Lu; Li, Shang-Zhong; Zhang, Jian-Jun; Wang, Yong; Dang, Yi; Wang, Lei

    2013-10-01

    Taking the fallow land with wheat stubble after harvesting as the control, a 4-year field experiment was conducted in a dryland of east Gansu, Northwest China to investigate the effects of rape cropping in summer fallow period on the soil moisture content, wheat yield, and water use efficiency (WUE). The rape was sown at 6 dates. There was a significant difference (P < 0.05) in the soil moisture content in summer fallow period when the rape was sown at different dates. When the rape was sown on August 5, the soil water storage efficiency was 58.5%, and the wheat yield and WUE were increased by 7.5% and 5.9%, respectively, as compared with the control. Averagely, cropping rape in fallow period could increase the wheat yield by 16. 1% in dry year and 6.8% in normal year. It was suggested that rape cropping in summer fallow period would benefit the wheat yield and drought resistance of drylands in Northwest China. PMID:24483074

  10. Vulnerability of Agriculture to Climate Change as Revealed by Relationships between Simulated Crop Yield and Climate Change Indices

    NASA Astrophysics Data System (ADS)

    King, A. W.; Absar, S. M.; Nair, S.; Preston, B. L.

    2012-12-01

    The vulnerability of agriculture is among the leading concerns surrounding climate change. Agricultural production is influenced by drought and other extremes in weather and climate. In regions of subsistence farming, worst case reductions in yield lead to malnutrition and famine. Reduced surplus contributes to poverty in agrarian economies. In more economically diverse and industrialized regions, variations in agricultural yield can influence the regional economy through market mechanisms. The latter grows in importance as agriculture increasingly services the energy market in addition to markets for food and fiber. Agriculture is historically a highly adaptive enterprise and will respond to future changes in climate with a variety of adaptive mechanisms. Nonetheless, the risk, if not expectation, of increases in climate extremes and hazards exceeding historical experience motivates scientifically based anticipatory assessment of the vulnerability of agriculture to climate change. We investigate the sensitivity component of that vulnerability using EPIC, a well established field-scale model of cropping systems that includes the simulation of economic yield. The core of our analysis is the relationship between simulated yield and various indices of climate change, including the CCI/CLIVAR/JCOM ETCCDI indices, calculated from weather inputs to the model. We complement this core with analysis using the DSSAT cropping system model and exploration of relationships between historical yield statistics and climate indices calculated from weather records. Our analyses are for sites in the Southeast/Gulf Coast region of the United States. We do find "tight" monotonic relationships between annual yield and climate for some indices, especially those associated with available water. More commonly, however, we find an increase in the variability of yield as the index value becomes more extreme. Our findings contribute to understanding the sensitivity of crop yield as part of

  11. Balanced nitrogen economy as a flexible strategy on yield stabilizing and quality of aquatic food crops in wetland ecosystem.

    PubMed

    Puste, A M; Sarkar, P K; Das, D K

    2005-12-01

    In wetland ecosystem, nitrogen along with other elements and its management is most imperative for the production of so many aquatic food, non-food and beneficial medicinal plants and for the improvement of soil and water characteristics. With great significant importance of INM (integrated nutrient management) as sources, emphasizing on management on nitrogen as a key element and its divergence, a case study was undertaken on such aquatic food crops (starch and protein-rich, most popular and remunerative) in the farmers' field of low-lying 'Tal' situation of New Alluvial Zone of Indian subtropics. The study was designed in factorial randomized block design, where, three important aquatic food crops (water chestnut (Trapa bispinosa Roxb.), makhana (Euryale ferox Salisb.) and water lily (Nymphaea spp.) as major factor and eleven combinations of organic and inorganic sources of nutrients as sub-factor was considered in the experiment. It revealed from the results that the production of fresh kernels or nuts of water chestnut (8.57 t ha(-1)), matured nut yield of makhana (3.06 t ha(-1)) and flower stalks of water-lily as vegetables (6.38 t ha(-1)) including its nutritional quality (starch, protein, sugar and minerals) was remarkably influenced with the application of both organic (neem oilcake @ 0.2 t ha(-1)) and inorganic sources (NPK @ 30:20:20 kg ha(-1) along with spraying of NPK @ 0.5% each over crop canopy at 20 days interval after transplanting) than the other INM combinations applied to the crops. Among the crops, highest WCYE (water chestnut yield equivalence) exhibited in makhana due to its high price of popped-form in the country, which is being exported to other countries at now. Sole application of both (organic and inorganic sources) with lower range did not produce any significant outcome from the study and exhibited lower value for all the crops. Besides production of food crops, INM also greatly influenced the soil and water characterization and it was

  12. Balanced nitrogen economy as a flexible strategy on yield stabilizing and quality of aquatic food crops in wetland ecosystem.

    PubMed

    Puste, A M; Sarkar, P K; Das, D K

    2005-09-01

    In wetland ecosystem, nitrogen along with other elements and its management is most imperative for the production of so many aquatic food, non-food and beneficial medicinal plants and for the improvement of soil and water characteristics. With great significant importance of INM (integrated nutrient management) as sources, emphasizing on management on nitrogen as a key element and its divergence, a case study was undertaken on such aquatic food crops (starch and protein-rich, most popular and remunerative) in the farmers' field of low-lying 'Tal' situation of New Alluvial Zone of Indian subtropics. The study was designed in factorial randomized block design, where, three important aquatic food crops (water chestnut (Trapa bispinosa Roxb.), makhana (Euryale ferox Salisb.) and water lily (Nymphaea spp.) as major factor and eleven combinations of organic and inorganic sources of nutrients as sub-factor was considered in the experiment. It revealed from the results that the production of fresh kernels or nuts of water chestnut (8.57 t ha(-1)), matured nut yield of makhana (3.06 t ha(-1)) and flower stalks of water-lily as vegetables (6.38 t ha(-1)) including its nutritional quality (starch, protein, sugar and minerals) was remarkably influenced with the application of both organic (neem oilcake @ 0.2 t ha(-1)) and inorganic sources (NPK @ 30:20:20 kg ha(-1) along with spraying of NPK @ 0.5% each over crop canopy at 20 days interval after transplanting) than the other INM combinations applied to the crops. Among the crops, highest WCYE (water chestnut yield equivalence) exhibited in makhana due to its high price of popped-form in the country, which is being exported to other countries at now. Sole application of both (organic and inorganic sources) with lower range did not produce any significant outcome from the study and exhibited lower value for all the crops. Besides production of food crops, INM also greatly influenced the soil and water characterization and it was

  13. 76 FR 65734 - Guidance for Industry on Evaluating the Safety of Flood-Affected Food Crops for Human Consumption...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-24

    ... HUMAN SERVICES Food and Drug Administration Guidance for Industry on Evaluating the Safety of Flood-Affected Food Crops for Human Consumption; Availability AGENCY: Food and Drug Administration, HHS. ACTION... entitled ``Guidance for Industry: Evaluating the Safety of Flood-Affected Food Crops for Human...

  14. New energy crop giant cane (Arundo donax L.) can substitute traditional energy crops increasing biogas yield and reducing costs.

    PubMed

    Luca, Corno; Pilu, Roberto; Tambone, Fulvia; Scaglia, Barbara; Adani, Fabrizio

    2015-09-01

    Giant cane is a promising non-food crop for biogas production. Giant cane and corn silages coming from full-scale fields were tested, in mixtures with pig slurry, for biomethane production by a continuous stirred tank lab-scale-reactor (CSTR) approach. Results indicated that giant cane produced less biomethane than corn, i.e. 174±10 N m(3) CH4 Mg(-1) TS(-1) and 245±26 N m(3) CH4 Mg(-1) TS(-1), respectively. On the other hand, because of its high field biomass production, the biogas obtainable per Ha was higher for giant cane than for corn, i.e. 12,292 N m(3) CH4 Ha(-1) and 4549 N m(3) CH4 Ha(-1), respectively. Low energetic and agronomic inputs for giant cane cultivation led to a considerable reduction in the costs of producing both electricity and biomethane, i.e. 0.50 € N m(-3) CH4(-1) and 0.81 € N m(-3) CH4(-1), and 0.10 € kW hEE(-1) and 0.19 € kW hEE(-1) for biomethane and electricity production, and for giant cane and corn mixtures respectively. PMID:25997008

  15. Ozone and density affect the response of biomass and seed yield to elevated CO2 in rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropospheric O3 reduces growth and yield of many crop species, whereas CO2 ameliorates the negative effects of O3. Thus in a combined elevated CO2 and O3 atmosphere, seed yield is at least restored to that of charcoal-filtered (CF) air at ambient CO2. The CO2-induced yield increase in CF air is hi...

  16. Plant-Based Assessment of Inherent Soil Productivity and Contributions to China’s Cereal Crop Yield Increase since 1980

    PubMed Central

    Fan, Mingsheng; Lal, Rattan; Cao, Jian; Qiao, Lei; Su, Yansen; Jiang, Rongfeng; Zhang, Fusuo

    2013-01-01

    Objective China’s food production has increased 6-fold during the past half-century, thanks to increased yields resulting from the management intensification, accomplished through greater inputs of fertilizer, water, new crop strains, and other Green Revolution’s technologies. Yet, changes in underlying quality of soils and their effects on yield increase remain to be determined. Here, we provide a first attempt to quantify historical changes in inherent soil productivity and their contributions to the increase in yield. Methods The assessment was conducted based on data-set derived from 7410 on-farm trials, 8 long-term experiments and an inventory of soil organic matter concentrations of arable land. Results Results show that even without organic and inorganic fertilizer addition crop yield from on-farm trials conducted in the 2000s was significantly higher compared with those in the 1980s — the increase ranged from 0.73 to 1.76 Mg/ha for China’s major irrigated cereal-based cropping systems. The increase in on-farm yield in control plot since 1980s was due primarily to the enhancement of soil-related factors, and reflected inherent soil productivity improvement. The latter led to higher and stable yield with adoption of improved management practices, and contributed 43% to the increase in yield for wheat and 22% for maize in the north China, and, 31%, 35% and 22% for early and late rice in south China and for single rice crop in the Yangtze River Basin since 1980. Conclusions Thus, without an improvement in inherent soil productivity, the ‘Agricultural Miracle in China’ would not have happened. A comprehensive strategy of inherent soil productivity improvement in China, accomplished through combining engineering-based measures with biological-approaches, may be an important lesson for the developing world. We propose that advancing food security in 21st century for both China and other parts of world will depend on continuously improving inherent soil

  17. Modelling crop yield, soil organic C and P under variable long-term fertilizer management in China

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Xu, Guang; Xu, Minggang; Balkovič, Juraj; Azevedo, Ligia B.; Skalský, Rastislav; Wang, Jinzhou; Yu, Chaoqing

    2016-04-01

    Phosphorus (P) is a major limiting nutrient for plant growth. P, as a nonrenewable resource and the controlling factor of aquatic entrophication, is critical for food security and human future, and concerns sustainable resource use and environmental impacts. It is thus essential to find an integrated and effective approach to optimize phosphorus fertilizer application in the agro-ecosystem while maintaining crop yield and minimizing environmental risk. Crop P models have been used to simulate plant-soil interactions but are rarely validated with scattered long-term fertilizer control field experiments. We employed a process-based model named Environmental Policy Integrated Climate model (EPIC) to simulate grain yield, soil organic carbon (SOC) and soil available P based upon 8 field experiments in China with 11 years dataset, representing the typical Chinese soil types and agro-ecosystems of different regions. 4 treatments, including N, P, and K fertilizer (NPK), no fertilizer (CK), N and K fertilizer (NK) and N, P, K and manure (NPKM) were measured and modelled. A series of sensitivity tests were conducted to analyze the sensitivity of grain yields and soil available P to sequential fertilizer rates in typical humid, normal and drought years. Our results indicated that the EPIC model showed a significant agreement for simulating grain yields with R2=0.72, index of agreement (d)=0.87, modeling efficiency (EF)=0.68, p<0.01 and SOC with R2=0.70, d=0.86, EF=0.59, and p<0.01. EPIC can well simulate soil available P moderately and capture the temporal changes in soil P reservoirs. Both of Crop yields and soil available were found more sensitive to the fertilizer P rates in humid than drought year and soil available P is closely linked to concentrated rainfall. This study concludes that EPIC model has great potential to simulate the P cycle in croplands in China and can explore the optimum management practices.

  18. The estimation of rice paddy yield with GRAMI crop model and Geostationary Ocean Color Imager (GOCI) image over South Korea

    NASA Astrophysics Data System (ADS)

    Yeom, J. M.; Kim, H. O.

    2014-12-01

    In this study, we estimated the rice paddy yield with moderate geostationary satellite based vegetation products and GRAMI model over South Korea. Rice is the most popular staple food for Asian people. In addition, the effects of climate change are getting stronger especially in Asian region, where the most of rice are cultivated. Therefore, accurate and timely prediction of rice yield is one of the most important to accomplish food security and to prepare natural disasters such as crop defoliation, drought, and pest infestation. In the present study, GOCI, which is world first Geostationary Ocean Color Image, was used for estimating temporal vegetation indices of the rice paddy by adopting atmospheric correction BRDF modeling. For the atmospheric correction with LUT method based on Second Simulation of the Satellite Signal in the Solar Spectrum (6S), MODIS atmospheric products such as MOD04, MOD05, MOD07 from NASA's Earth Observing System Data and Information System (EOSDIS) were used. In order to correct the surface anisotropy effect, Ross-Thick Li-Sparse Reciprocal (RTLSR) BRDF model was performed at daily basis with 16day composite period. The estimated multi-temporal vegetation images was used for crop classification by using high resolution satellite images such as Rapideye, KOMPSAT-2 and KOMPSAT-3 to extract the proportional rice paddy area in corresponding a pixel of GOCI. In the case of GRAMI crop model, initial conditions are determined by performing every 2 weeks field works at Chonnam National University, Gwangju, Korea. The corrected GOCI vegetation products were incorporated with GRAMI model to predict rice yield estimation. The predicted rice yield was compared with field measurement of rice yield.

  19. [Effects of different film mulch and ridge-furrow cropping patterns on yield formation and water translocation of rainfed potato].

    PubMed

    Qin, Shu-Hao; Zhang, Jun-Lian; Wang, Di; Pu, Yu-Lin; Du, Quan-Zhong

    2011-02-01

    This paper studied the effects of different film mulch and ridge-furrow cropping patterns on the yield formation and water translocation of rainfed potato in the semi-arid area of west Loess Plateau. Comparing with those under traditional harrowed bedding without film mulch (T1), the potato yield under harrowed bedding with film mulching (T2), completely mulched alternating narrow and wide ridges with furrow planting (T3), completely mulched alternating narrow and wide ridges with ridge planting (T4), mulched raised bedding with furrow planting (T5), and mulched raised bedding with bedding planting (T6) was increased by 50.1%, 75.9%, 86.8%, 69.6%, and 60. 6%, and the water use efficiency (WUE) was increased by 47.0%, 82.7%, 84.0%, 75.2%, and 54.3% respectively, with the increments being the highest under T4 and T3. All the film much and ridge-furrow cropping patterns improved the yield component of potato, and T4 and T3 were most beneficial to the increase of mid and big tubers, tuber number per plant, and tuber yield per plant, and to the decrease of the proportions of green and blet tubers. It was concluded that completely mulched alternating narrow and wide ridges with ridge planting (T4) and completely mulched alternating narrow and wide ridges with furrow planting (T3) were the two better cropping patterns in water-saving and high yielding for potato cultivation in semiarid areas. PMID:21608252

  20. Simulated crop yield in response to changes in climate and agricultural practices: results from a simple process based model

    NASA Astrophysics Data System (ADS)

    Caldararu, S.; Smith, M. J.; Purves, D.; Emmott, S.

    2013-12-01

    Global agriculture will, in the future, be faced with two main challenges: climate change and an increase in global food demand driven by an increase in population and changes in consumption habits. To be able to predict both the impacts of changes in climate on crop yields and the changes in agricultural practices necessary to respond to such impacts we currently need to improve our understanding of crop responses to climate and the predictive capability of our models. Ideally, what we would have at our disposal is a modelling tool which, given certain climatic conditions and agricultural practices, can predict the growth pattern and final yield of any of the major crops across the globe. We present a simple, process-based crop growth model based on the assumption that plants allocate above- and below-ground biomass to maintain overall carbon optimality and that, to maintain this optimality, the reproductive stage begins at peak nitrogen uptake. The model includes responses to available light, water, temperature and carbon dioxide concentration as well as nitrogen fertilisation and irrigation. The model is data constrained at two sites, the Yaqui Valley, Mexico for wheat and the Southern Great Plains flux site for maize and soybean, using a robust combination of space-based vegetation data (including data from the MODIS and Landsat TM and ETM+ instruments), as well as ground-based biomass and yield measurements. We show a number of climate response scenarios, including increases in temperature and carbon dioxide concentrations as well as responses to irrigation and fertiliser application.

  1. 7 CFR 1412.31 - Direct payment yields for covered commodities, except pulse crops.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... for covered commodities at part 1412 of this chapter in effect on January 1, 2008 (see 7 CFR part 1412... 7 Agriculture 10 2011-01-01 2011-01-01 false Direct payment yields for covered commodities, except... Establishment of Yields for Direct and Counter-Cyclical Payments § 1412.31 Direct payment yields for...