Department of Civil and Environmental Engineering, and Institute of the Environment, University of Connecticut, Storrs, CT, USA.
Department of Civil and Environmental Engineering, and Institute of the Environment, University of Connecticut, Storrs, CT, USA.
Sci Total Environ. 2020 Jun 25;723:137893. doi: 10.1016/j.scitotenv.2020.137893. Epub 2020 Mar 12.
Food security has been and will continue to be a major challenge in Ethiopia. The country's smallholder, rainfed agriculture renders its food production system extremely vulnerable to climate variability and extremes. In this study, we investigate the impact of past climate variability and change on the yields of five major cereal crops in Ethiopia-barley, maize, millet, sorghum, and wheat-during the period 1979-2014 using the Decision Support System for Agrotechnology Transfer (DSSAT) crop model. The model is calibrated at both the site and agroecological-zone scales. At the sites studied, the model results suggest that climate in the past four decades may have contributed to an increasing trend in maize yield, a decreasing trend in wheat yield, and no clear trend in the yields of barley and millet; cereal crop yield is positively correlated with growing season solar radiation and temperature, but negatively correlated with growing season precipitation. For modeled cereal crops across the nation during the study period, yield in western Ethiopia is positively correlated with solar radiation and day time temperature; in the eastern and southeastern Ethiopia where water is a limiting factor for growth, yield is positively correlated with precipitation but negatively correlated with solar radiation and both day time and night time temperature. The national average of simulated yields of most crops (except maize) showed an overall decreasing (although not statistically significant) trend induced by past climate variability and changes. Over a large portion of the highly productive areas where there is a negative correlation between yield and temperature, yield is simulated to have significantly decreased over the past four decades, an indication of adverse climate impact in the past and potential food security concern in the future.
食品安全一直是并将继续是埃塞俄比亚的主要挑战。该国的小农、雨养农业使粮食生产系统极易受到气候变异性和极端情况的影响。在本研究中，我们使用决策支持系统农业技术转让（DSSAT）作物模型，研究了过去气候变异性和变化对 1979-2014 年间埃塞俄比亚五种主要谷物作物（大麦、玉米、小米、高粱和小麦）产量的影响。该模型在站点和农业生态区尺度上进行了校准。在所研究的地点，模型结果表明，过去四十年的气候可能导致玉米产量呈上升趋势，小麦产量呈下降趋势，大麦和小米产量没有明显趋势；谷物作物产量与生长季节太阳辐射和温度呈正相关，但与生长季节降水呈负相关。对于研究期间全国模拟的谷物作物，埃塞俄比亚西部的产量与太阳辐射和白天温度呈正相关；在东部和东南部，水是生长的限制因素，产量与降水呈正相关，但与太阳辐射以及白天和夜间温度呈负相关。在大部分作物（除玉米外）的模拟产量中，过去气候变异性和变化引起的全国平均产量总体呈下降趋势（尽管没有统计学意义）。在高生产力地区的很大一部分地区，产量与温度呈负相关，过去四十年的产量预计会显著下降，这表明过去气候的不利影响以及未来粮食安全的潜在担忧。
