Climate Sensitivity of Kharif Rice Yield in Manipur, Northeast India

Abstract

Aims: This study quantifies climatic drivers of Kharif-season rice yield variability in Manipur. Study design: The present study was conducted using seasonally aggregated rainfall and temperature indicators with regression-based attribution and scenario modelling.   Place and Duration of Study: This study focused on the state of Manipur in Northeast India, where rice constitutes the dominant staple crop and agricultural production is largely dependent on monsoon rainfall. The present study was conducted during 2014–2021 using seasonal climate data obtained from the Indian Meteorological Department (IMD) Data Service Portal. Methodology: Climate data were aggregated over the Kharif growing season (June–October) to represent hydroclimatic conditions relevant to key rice growth stages. The analysis estimated bivariate relationships between rice yield and rainfall, and between rice yield and temperature, as well as conditional (partial) effects that controlled for covariance between the two climate variables. A structural multivariate model was subsequently used to generate mean yield projections under counterfactual climate perturbations relative to a recent baseline period. Results: Seasonal rainfall during the Kharif period exhibited pronounced inter-annual variability, ranging from 589.6 to 1252.1 mm, whereas seasonal mean temperature varied within a comparatively narrow range (25.2–26.1 °C). Rice yield fluctuated substantially between 1.74 and 2.68 t ha⁻¹. Correlation analysis revealed a strong negative association between rainfall and yield (r = −0.78) and a weaker negative association between temperature and yield (r = −0.54). Regression results indicate that a 100 mm increase in Kharif-season rainfall is associated with an average yield reduction of approximately 0.10 t ha⁻¹ over 2014–2021, while temperature effects are not statistically significant once rainfall is accounted for. Across bivariate, conditional, and multivariate specifications, rainfall consistently emerged as the dominant climatic driver, with higher seasonal rainfall significantly reducing yield (β ≈ −0.001, p < 0.05), whereas temperature effects remained statistically weak. The joint climate model explained 70% of inter-annual yield variation (R² = 0.700). Scenario projections anchored to recent climate conditions yielded a baseline estimate of 2.44 t ha⁻¹ and indicated progressively larger yield declines under wetter and warmer conditions. Conclusion: Overall, short-term climate risk in Manipur’s rainfed rice systems is governed primarily by rainfall variability, particularly excess monsoon precipitation, highlighting the need for adaptation strategies focused on flood management, drainage, climate-resilient varieties, and early-warning systems.