Optimal rainfall threshold for monsoon rice production in India varies across space and time

Climate change affects Indian agriculture, which depends heavily on the spatiotemporal distribution of monsoon rainfall. Despite the nonlinear relationship between crop yield and rainfall, little is known about the optimal rainfall threshold, particularly for monsoon rice. Here, we investigate the responses of rice yield to monsoon rainfall in India by analyzing historical rice production statistics and climate data from 1990 to 2017. Results show that excessive and deficit rainfall reduces rice yield by 33.7% and 19%, respectively. The overall optimal rainfall threshold nationwide is 1621 ± 34 mm beyond which rice yield declines by 6.4 kg per hectare per 100 mm of rainfall, while the identifiable thresholds vary spatially across 14 states. The temporal variations in rice yield are influenced by rainfall anomalies featured by El Niño-Southern Oscillation events.

Arabinda Maiti, Md Kamrul Hasan, Srikanta Sannigrahi, Somnath Bar, Suman Chakraborti, Shanti Shwarup Mahto, Sumanta Chatterjee, Suvamoy Pramanik, Francesco Pilla, Jeremy Auerbach, Oliver Sonnentag, Conghe Song, Qi Zhang