Analysis of temperature variability and extremes with respect to crop threshold temperature for Maharashtra, India

Temperature is one of the prime factors affecting crop yield and thereby, in changing climate, it is imperative to investigate the co-variability of crop yield and temperature change. Temperature change can manifest itself in multiple factors such as deviation from long-period average, daily scale variability and frequency/intensity of extreme temperature events. To add to the complexity, each of these factors can affect the crop yield differently which necessitates understanding their effect on crop yield individually as well as collectively. Concerning this, we evaluated their distinct and combined impact with respect to threshold temperature of three major crops, i.e. sorghum, sugarcane and millet sown across the Maharashtra State of India. Further, the temperature parameters were conflated using confirmatory factor analysis to formulate a temperature variability index (TVI) that helped in identifying the collective impact of these multiple factors on each crop. Results show that the TVI and sugarcane yield for Nagpur and Bhandara districts of the Vidarbha region exhibited negative co-variability (− 0.30/year), implying the negative impact of temperature change on sugarcane. For sorghum, Wardha and Bhandara of Vidarbha region, Solapur of Pune region and Ratnagiri of Konkan region exhibited negative co-variability with TVI (~− 0.2 to − 0.4/year). Contrary to sugarcane and sorghum, for millets, Akola, Amravati and Chandarpur districts in Vidarbha region; Hingoli, Parbhani, Nanded and Osmanabad in Marathwada region; Satara and Sangli in Pune region; Jalgaon in Nashik region and Ratnagiri; and Sindhudurg in Konkan region exhibited positive co-variability (0.50/year), signifying the favourable temperature conditions for sowing millet. Overall, due to the high exposure of districts to temperature change in Vidarbha and Pune regions, farmers in these districts are advised to refrain from sowing sorghum and sugarcane; instead, farmers can moderate the adverse effects of climate change by sowing millet due to the existence of conducive temperature for millet in Maharashtra. Further, analysis was used to suggest the region and climate-specific cropping pattern for other districts of Maharashtra that can be used by the policy makers to improve the situation of agriculture, farmers and economy of India.