Climate change to trigger higher wheat crop losses than thought

Nature India ◽  
2015 ◽  
2020 ◽  
Vol 12 (19) ◽  
pp. 8256
Author(s):  
Vanshika Dhamija ◽  
Roopam Shukla ◽  
Christoph Gornott ◽  
PK Joshi

In India, a reduction in wheat crop yield would lead to a widespread impact on food security. In particular, the most vulnerable people are severely exposed to food insecurity. This study estimates the climate change vulnerability of wheat crops with respect to heterogeneities in time, space, and weighting methods. The study uses the Intergovernmental Panel on Climate Change (IPCC) framework of vulnerability while using composite indices of 27 indicators to explain exposure, sensitivity, and adaptive capacity. We used climate projections under current (1975–2005) conditions and two future (2021–2050) Representation Concentration Pathways (RCPs), 4.5 and 8.5, to estimate exposure to climatic risks. Consistency across three weighting methods (Analytical Hierarchy Process (AHP), Principal Component Analysis (PCA), and Equal Weights (EWs)) was evaluated. Results of the vulnerability profile suggest high vulnerability of the wheat crop in northern and central India. In particular, the districts Unnao, Sirsa, Hardoi, and Bathinda show high vulnerability and high consistency across current and future climate scenarios. In total, 84% of the districts show more than 75% consistency in the current climate, and 83% and 68% of the districts show more than 75% consistency for RCP 4.5 and RCP 8.5 climate scenario for the three weighting methods, respectively. By using different weighting methods, it was possible to quantify “method uncertainty” in vulnerability assessment and enhance robustness in identifying most vulnerable regions. Finally, we emphasize the importance of communicating uncertainties, both in data and methods in vulnerability research, to effectively guide adaptation planning. The results of this study would serve as the basis for designing climate impacts adjusted adaptation measures for policy interventions.


2017 ◽  
Vol 12 (3) ◽  
Author(s):  
Rafia Mumtaz ◽  
Shahbaz Baig ◽  
Iram Fatima

Land management for crop production is an essential human activity that supports life on Earth. The main challenge to be faced by the agriculture sector in coming years is to feed the rapidly growing population while maintaining the key resources such as soil fertility, efficient land use, and water. Climate change is also a critical factor that impacts agricultural production. Among others, a major effect of climate change is the potential alterations in the growth cycle of crops which would likely lead to a decline in the agricultural output. Due to the increasing demand for proper agricultural management, this study explores the effects of meteorological variation on wheat yield in Chakwal and Faisalabad districts of Punjab, Pakistan and used normalised difference vegetation index (NDVI) as a predictor for yield estimates. For NDVI data (2001-14), the NDVI product of Moderate Resolution Imaging spectrometer (MODIS) 16-day composites data has been used. The crop area mapping has been realised by classifying the satellite data into different land use/land covers using iterative self-organising (ISO) data clustering. The land cover for the wheat crop was mapped using a crop calendar. The relation of crop yield with NDVI and the impact of meteorological parameters on wheat growth and its yield has been analysed at various development stages. A strong correlation of rainfall and temperature was found with NDVI data, which determined NDVI as a strong predictor of yield estimation. The wheat yield estimates were obtained by linearly regressing the reported crop yield against the time series of MODIS NDVI profiles. The wheat NDVI profiles have shown a parabolic pattern across the growing season, therefore parabolic least square fit (LSF) has been applied prior to linear regression. The coefficients of determination (<em>R</em><sup>2</sup>) between the reported and estimated yield was found to be 0.88 and 0.73, respectively, for Chakwal and Faisalabad. This indicates that the method is capable of providing yield estimates with competitive accuracies prior to crop harvest, which can significantly aid the policy guidance and contributes to better and timely decisions.


2014 ◽  
Vol 65 (2) ◽  
pp. 194 ◽  
Author(s):  
D. C. Phelan ◽  
D. Parsons ◽  
S. N. Lisson ◽  
G. K. Holz ◽  
N. D. MacLeod

Although geographically small, Tasmania has a diverse range of regional climates that are affected by different synoptic influences. Consequently, changes in climate variables and climate-change impacts will likely vary in different regions of the state. This study aims to quantify the regional effects of projected climate change on the productivity of rainfed pastoral and wheat crop systems at five sites across Tasmania. Projected climate data for each site were obtained from the Climate Futures for Tasmania project (CFT). Six General Circulation Models were dynamically downscaled to ~10-km grid cells using the CSIRO Conformal Cubic Atmospheric Model under the A2 emissions scenario for the period 1961–2100. Mean daily maximum and minimum temperatures at each site are projected to increase from a baseline period (1981–2010) to 2085 (2071–2100) by 2.3–2.7°C. Mean annual rainfall is projected to increase slightly at all sites. Impacts on pasture and wheat production were simulated for each site using the projected CFT climate data. Mean annual pasture yields are projected to increase from the baseline to 2085 largely due to an increase in spring pasture growth. However, summer growth of temperate pasture species may become limited by 2085 due to greater soil moisture deficits. Wheat yields are also projected to increase, particularly at sites presently temperature-limited. This study suggests that increased temperatures and elevated atmospheric CO2 concentrations are likely to increase regional rainfed pasture and wheat production in the absence of any significant changes in rainfall patterns.


2020 ◽  
Vol 41 (01) ◽  
Author(s):  
Amare Aleminew ◽  
Merkuz Abera

Climate change is a recent challenge on crop production and productivity in the world. The objective of this paper is to review the major effects of climate change on the production and productivity of wheat in the high lands of Ethiopia. Effects of climate change on wheat would be mainly through changes in [CO2], temperature, rainfall, length of growing period, actual growth rate and increased evapo-transpiration, which may lead to reduce yield or complete crop failure. Moreover, flower fertilization and grain set are highly sensitive to heat stress during mid-anthesis. In C3 crops like wheat, the elevated CO2 level is expected to increase productivity as a result of higher CO2 diffusion through stomata leading to a higher photosynthesis rate. But, elevated [CO2] may have negative effects on the grain-quality of wheat in terms of protein, lipids, number of mitochondria and nitrogen contents. Unlike CO2, elevated temperature affects crop production negatively by increasing rate of respiration; hastening plant growth and development; increasing photorespiration of wheat, reducing photosynthetic efficiency due to O2 interrupts the photosynthetic path way instead of CO2, increasing rate of water loss by increasing evapo-transpiration and decreasing nutrient use-efficiency through increased rate of decomposition and mineralization. As a result, wheat area is forecast to be displaced by other crop types. In order to tackle this issue, major mitigation and adaptation measures for example promoting area closures and conservation agriculture-based (CA), agroforestry practices, efficient use of energy sources, etc. should be practiced and given special attention by the communities as well as the government to solve the effects of climate change on wheat production and productivity in the country.


2012 ◽  
Vol 21 (4) ◽  
pp. 384-408 ◽  
Author(s):  
Heikki Laurila ◽  
Pirjo Mäkelä ◽  
Jouko Kleemola ◽  
Jari Peltonen

In this study Mixed structural covariance, Path and Cultivation Value analyses and the CERES-Wheat crop model were used to evaluate vegetation and yield component variation affecting yield potential between different high-latitude (> 60° N lat.) and mid-European (< 60° N lat.) spring wheat (Triticum aestivum L.) genotypes currently cultivated in southern Finland. Path modeling results from this study suggest that especially grains/ear, harvest index (HI) and maximum 1000 kernel weight were significant factors defining the highest yield potential. Mixed and Cultivation value modeling results suggest that when compared with genotypes introduced for cultivation before 1990s, modern spring wheat genotypes have a significantly higher yielding capacity, current high yielding mid-European genotypes even exceeding the 5 t ha-1 non-potential baseline yield level (yb). Because of a forthcoming climate change, the new high yielding wheat genotypes have to adapt for elevated temperatures and atmospheric CO2 growing conditions in northern latitudes. The optimized ideotype profiles derived from the generic high-latitude and mid-European genotypes are presented in the results. High-latitude and mid-European ideotype profiles with factors estimating the effects of concurrent elevated CO2 and temperature levels with photoperiodical daylength effects can be utilized when designing future high yielding ideotypes adapted to future growing conditions. The CERES-Wheat ideotype modeling results imply, that with new high yielding mid-European ideotypes, the non-potential baseline yield (yb) would be on average 5150 kg ha-1 level (+ 108 %) vs. new high-latitude ideotypes (yb 4770 kg ha-1, 100%) grown under the elevated CO2(700ppm)×temperature(+3ºC) growing conditions projected by the year 2100 climate change scenario in southern Finland.


2010 ◽  
Vol 58 (Supplement 1) ◽  
pp. 83-88
Author(s):  
N. Harnos ◽  
É. Erdélyi ◽  
T. Árendás

Nowadays, studying the impact of climate change on agricultural crops is of great importance in national and international projects. Research on the effects of climate change on agricultural cultivars is supported by crop growth models. Simulations provide facilities for the low cost investigation of the effects of many factors, both independently of each other and in combination. These models require parameterisation and testing, which can be done using data measurements. In order to test the correctness of the simulations of meteorological and nutrient supply effects, it is necessary to use the results of long-term field experiments with many replicates.In the present study, the Ceres Wheat and AFRCWHEAT2 winter wheat crop growth models were tested, utilizing the data of a five-year sowing date experiment and the relevant meteorological data. An analysis was made of whether changes in the sowing date were able to influence or eliminate the negative effects of the changing climate. It was found that choosing the optimum sowing date could be the key to adapting to changing conditions.


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