Identifying most promising agronomic adaptation strategies to close rainfed rice yield gap in future: a model-based assessment

Abstract

Abstract There is an increasing consensus that climate change may have a high negative impact on crop yield, and that it will affect farmers in developing and least developed counties the most. ‘Closing the yield gap’ could be one of the promising options to address the issue of yield improvement. Better understanding of adaptation strategies and implications of the adaptations in crop yield are required to close the yield gap. In this study, the effectiveness of agronomic adaptation options on the rainfed rice yield gap was evaluated for the baseline period (1981–2005) and two future periods (2016–2040 and 2026–2050) for India by using bias-corrected RegCM4 output and the Decision Support System for Agrotechnology Transfer (DSSAT) model. Results suggested that a combined adjustment of transplanting time (advancing by fortnight), crop spacing ((10 × 10) cm) and N-fertilizer application (140 kg/ha) was the best strategy as compared to the single adaptation option to close the yield gap under the climate change scenario. The strategy improved rice yield by 37.5–168.0% and reduced the average attainable yield gap among the cultivars from 0.74 to 0.16 t/ha under future climate projection. This study provides agronomic indications to rice growers and lays the basis for an economic analysis to support policy-makers in charge of promoting the sustainability of the rainfed rice-growing systems.