Challenges and technological interventions in rice–wheat system for resilient food–water–energy-environment nexus in North-western Indo-Gangetic Plains: A review

Rice (Oryza sativa L.)–wheat (Triticum aestivum L.) cropping system in north-western Indo-Gangetic Plains performed a crucial role in the national food security. However, the widespread and intensive cultivation of this system has led to serious problems such as declining groundwater table (~1 meter year(−1)) with sharp increase in number of districts under over-exploitation category, residue burning, higher greenhouse gases emission and herbicide resistance in weeds, causing stagnant crop productivity and lesser profitability. In this review article, an attempt has been made to discuss the major issues pertaining to intensive rice–wheat cultivation amidst climate vagaries and futuristic approach to address these challenges. Different tillage- and crop-specific recommendations such as adoption of direct seeded rice, diversification with lesser resource guzzling crops such as maize (Zea mays L.) at least on the periodic manner especially in light-medium soils, inclusion of summer legumes and alternative tillage systems (permanent beds and zero tillage with residue retention) have been suggested to address these issues. However, crop performance under these techniques has been found to be location, soil and cultivar specific. The absence of aerobic tailored genotypes and weeds have been identified as the major constraints in adoption of direct seeded rice. The integrated strategies of conservation tillage, crop breeding program and resource conserving region- and soil-specific agronomic measures with crop diversification would be helpful in tackling the sustainability issues. It requires future efforts on developing crop genotypes suited to conservation tillage, effective weed control strategies and trainings and demonstrations to farmers to switch from conventional rice–wheat system to alternative cropping systems.