Department of Civil and Environmental Engineering, Universitas Gadjah Mada, Yogyakarta, Indonesia.
Graduate School of Environmental Studies, Tohoku University, Sendai, Japan.
PLoS One. 2023 Feb 2;18(2):e0281287. doi: 10.1371/journal.pone.0281287. eCollection 2023.
In recent decades, droughts have critically limited crop production, inducing food system shocks regionally and globally. It was estimated that crop yield variability in around one-third to three-fourths of global harvested areas is explained significantly by drought, revealing the notable vulnerability of crop systems to such climate-related stressors. However, understanding the key factors determining the global pattern of crop yield sensitivity to drought is limited. Here, we investigate a wide range of physical and socioeconomic factors that may determine crop-drought vulnerability in terms of yield sensitivity to drought based on the Standardized Precipitation Index at 0.5° resolution from 1981 to 2016 using machine learning approaches. The results indicate that the spatial variations of the crop-drought sensitivity were mainly explained by environmental factors (i.e., annual precipitation, soil water-holding capacity, soil acidity, annual potential evapotranspiration) and crop management factors (i.e., fertilizer rate, growing season). Several factors might have a positive effect in mitigating crop-drought vulnerability, such as annual precipitation, soil water holding capacity, and fertilizer rate. This study quantitatively assesses the possible effect of various determinants which might control crop vulnerability to drought. This understanding may provide insights for further studies addressing better crop vulnerability measures under future drought stress.
近几十年来，干旱严重限制了作物产量，在区域和全球范围内引发了粮食系统冲击。据估计，约三分之一到四分之三的全球已收获面积的作物产量变异性可显著归因于干旱，这表明作物系统对这种与气候相关的胁迫因素明显脆弱。然而，对于决定作物对干旱敏感性的全球格局的关键因素的理解有限。在这里，我们利用机器学习方法，根据 1981 年至 2016 年 0.5°分辨率的标准化降水指数，研究了广泛的物理和社会经济因素，这些因素可能决定了作物对干旱的脆弱性，即对干旱的产量敏感性。结果表明，作物对干旱敏感性的空间变化主要由环境因素（即年降水量、土壤持水能力、土壤酸度、年潜在蒸散量）和作物管理因素（即施肥率、生长季节）解释。一些因素可能具有减轻作物对干旱脆弱性的积极作用，例如年降水量、土壤持水能力和施肥率。本研究定量评估了各种决定因素可能对控制作物对干旱脆弱性的可能影响。这种理解可能为进一步研究在未来干旱胁迫下更好地衡量作物脆弱性提供思路。
