1,721,215 research outputs found
Has climate change opened new opportunities for wheat cropping in Argentina?
No full textAs a result of climate change, and in particular rainfall changes, agricultural production is likely to change across the globe. Until now most research has focused on areas which will become unsustainable for agricultural production. However, there are also regions where climate change might actually improve conditions for growth. In the western Pampas region of Argentina, average annual rainfall has increased by 100–200 mm over the last 70 years, mainly during summer. Wheat is grown during winter, primarily on stored soil water and the main factor limiting plant production in this area is rainfall. Using the well tested simulation model APSIM-NWheat, we studied whether recent climate change has potentially opened new opportunities for wheat cropping in Argentina. Simulation results indicated that the additional rainfall in the Pampas of Argentina has increased the achievable yield (defined as the yield limited by solar radiation, temperature, water and nitrogen supply) of wheat in the currently cropped region, but less than expected based on the large amount of additional rainfall. The higher achievable yield from additional rainfall could potentially allow an expansion of profitable wheat cropping into currently non-cropped areas, where the achievable wheat yield increased in average from 1 t/ha to currently 2 t/ha. However, the poor water-holding capacity of the sandy soils which dominate the region outside the current cropping area limits the systems ability to use most of the increased summer rainfall. Nevertheless, the current higher achievable yield indicates a suitability of the region for cropping, which will slightly decline or remain unchanged depending on summer rainfall storage, with current and future climate change, including projected changes in rainfall, temperature and atmospheric CO2 concentration. Factors other than just the achievable yield will eventually influence any future development of this region for cropping, including the high sensitivity of the sandy soils to erosion and nutrient leaching, current relatively high land prices, restrictions on clearing for cropping, the distance to the nearest port and current unsuitable cultivars withstanding the high frost risk.Instituto de Clima y AguaFil: Asseng, Senthold. University of Florida. Agricultural & Biological Engineering Department; Estados Unidos. Commonwealth Scientific and Industrial Research Organisation. Plant Industry; AustraliaFil: Travasso, Maria Isabel. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; ArgentinaFil: Ludwig, Fulco. Wageningen University. Earth System Science and Climate Change Group; HolandaFil: Magrin, Graciela Odilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; Argentin
Simulation of winter wheat response to variable sowing dates and densities in a high-yielding environment
No full textAbstract Crop multi-model ensembles (MME) have proven to be effective in increasing the accuracy of simulations in modelling experiments. However, the ability of a MME to capture crop response to changes in sowing dates and densities has not yet been investigated. These management interventions are some of the main levers for adapting cropping systems to climate change. Here, we explore the performance of a MME of 29 wheat crop models to predict the effect of changing sowing dates and rates on yield and yield components, on two sites located in a high-yielding environment in New Zealand. The experiment was conducted for 6 years and provided 50 combinations of sowing date, sowing density and growing season.”. We show that the MME simulates seasonal growth of wheat well under standard sowing conditions, but fails under early sowing and high sowing rates. The comparison between observed and simulated in-season fraction of intercepted photosynthetically active radiation (FIPAR) for early sown wheat shows that the MME does not capture the decrease of crop above ground biomass during winter months due to senescence. Models need to better account for tiller competition for light, nutrients and water during vegetative growth, and early tiller senescence and tiller mortality, which are exacerbated by early sowing, high sowing densities and warmer winter temperatures
Effects of changes in climatic means, variability, and agro-technologies on future wheat and maize yields at 10 sites across the globe
No full textA Crop Simulation Model for Tef (Eragrostis tef (Zucc.) Trotter)
No full textTef is an Ethiopian staple grain that provides both food security and income for smallholders. As tef is nutritious and gluten free, it is also gaining popularity as a health food. A tef model was calibrated based on the Decision Support System for Agrotechnology Transfer's (DSSAT) NWheat model and included parameter changes in phenology, photoperiod response, radiation use efficiency, and transpiration efficiency for both standard and elevated atmospheric CO2, based on published literature for tef and other C4 species. The new DSSAT-Tef model was compared with tef field experiments. DSSAT-Tef accurately simulated phenology and responded to changes in N supply and irrigation, but overestimated growth and occasionally yields. Simulation-observation comparisons resulted in an RMSE of 2.5 days for anthesis, 4.4 days for maturity, 2624 kg/ha (49.6%) for biomass, and 475 kg/ha (41.0%) for grain yield. Less data were available for N uptake, and the model simulated crop N uptake with an RMSE of 45 kg N/ha (46.2%) and 15 kg N/ha (37.3%) for grain N. While more data from contrasting environments are needed for further model testing, DSSAT-Tef can be used to assess the performance of crop management strategies, the suitability of tef for cultivation across growing environments, and food security
Uncertainties of Climate Change Impacts in Agriculture
No full textAbstractCrop simulation models are often used to estimate the impact of climate change on agricultural production. But, simulated climate change impacts vary across agricultural impact models due to differences in model structures and parameter values. When comparing crop models with standardised inputs, uncertainties in simulated impacts increased with higher temperatures1 and CO2 concentrations2,3. These uncertainties in impact simulations are larger due to crop models, than due to downscaled general circulation models2. Impact uncertainties can be reduced by improving model routines and parameters with detailed field experimentations. However, multi-model ensemble medians also supply an improved prediction above individual models4. Less uncertainty in describing how climate change may affect agricultural productivity is needed to assist in the development of adaptation strategies and policies
Global needs for nitrogen fertilizer to improve wheat yield under climate change
No full textInternational Wheat Yield PartnershipDeutsche Forschungsgemeinschaft https://doi.org/10.13039/501100001659Chilean Technical and Scientific Research CouncilItalian Ministry for Agricultural, Food, and Forestry PoliciesMinistry of Education, Youth and Sports of Czech Republi
Climate change impacts on wheat production in a Mediterranean environment in Western Australia
No full textPotential benefits of early vigor and changes in phenology in wheat to adapt to warmer and drier climates
No full textDeveloping crop cultivars with novel traits could help agriculture adapt to climate change. As introducing new traits into crops is expensive and time consuming, it is helpful to develop methods which can test whether a potential new plant trait increases or maintains production in future climates. We used a crop-soil simulation model (APSIM-Nwheat) to test whether changes in physiological traits, related to early vigor and flowering time, would result in increased yield when compared to traditional cultivars of wheat grown at higher temperatures, elevated atmospheric CO2 and lower rainfall in a Mediterranean climate. Early vigor was simulated by changing four different plant traits. The impact of each trait on grain yield varied with climate scenario and soil type. Higher specific leaf area had minimal effect on yield for the historical climate, but it could increase production in future warmer climates. Increased rooting depth generally had a positive impact on yield, while lower radiation use efficiency and earlier flowering tended to reduce yield. The interaction between these traits was generally positive, and our results indicate that early vigor may improve yield for a range of future climate scenarios. However, in the low rainfall regions, early vigor is unlikely to compensate for rainfall reductions of [greater-or-equal, slanted]30%. Yield gains for early vigor are likely to be larger on sandy loam than on heavier clay soil. The simulation of cultivars differing in flowering time showed that in drier climates earlier flowering cultivars increase potential yield while in warming climates later cultivars increase yield. In conclusion, our analyses suggest that there is great potential for adapting wheat systems to climate change by introducing cultivars with new traits. Our results also show how simulation analyses can assist plant breeders in determining which traits could be important for crop production in future climates.APSIM Australia CO2 Crop production Global change
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