Investigating historical climatic impacts on wheat yield in India using a statistical modeling approach

Abstract

Wheat is an important food security crop supporting the livelihood of a large population across the world. Though climatic change has been affecting wheat yields globally, the detailed study on the historical climatic impacts on wheat yield in India is mostly missing. There are two approaches to assess the climatic impacts on crop yields: process-based models, and statistical models. The present manuscript investigates the historical climatic impacts on wheat yield in India using a statistical modeling approach. Fifty years of wheat yield and climate data (panel data comprising 175 Indian districts) were fitted in the six statistical models over the periods 1966–2015, 1966–75, 1976–85, 1986–95, 1996–05, and 2006–15. We found that (1) minimum and maximum temperatures have impacted wheat yield negatively in almost all the periods (except during 1966–75 and 1996–05 for maximum temperature). The estimated regression coefficients demonstrating the effect of minimum and maximum temperatures on wheat yield were − 43.74 kg/ha per °C (p < 0.001) and − 101.80 kg/ha per °C (p < 0.001) during 1966–15. (2) Precipitation and wet days did not impact wheat yield significantly during 1966–2015, but affected wheat yields negatively during 1996–05, and positively during 1976–85 and 1986–95. (3) Potential evapotranspiration and vapor pressure have impacted wheat yield negatively in almost all the periods (except during 1966–75 and 1996–05 for potential evapotranspiration). The estimated regression coefficients demonstrating the effect of potential evapotranspiration and vapor pressure on wheat yield were − 75.12 kg/ha per cm/day (p < 0.001) and − 49.98 kg/ha per hPa (p < 0.001) during 1966–2015. Our research findings highlight that temperatures, potential evapotranspiration, and vapor pressure have a more profound negative impact on wheat yield as compared to precipitation and wet days. This detailed analysis of historical climatic impacts on wheat yield is the first step towards achieving the bigger goal of identifying and recommending appropriate mitigation strategies. The results of this study are highly relevant for planners and policymakers in India and globally.