Overview of agronomic research for greening rice (Oryza sativa)-fallows during winter in India

An estimated area of 11.65 million hectare (m ha) accounting for 29% of rainy season (kharif) rice (Oryza sativa L.) area, remains fallow during the winter season in India. The climate of rice-fallow areas varies from sub-humid to per humid. Short-duration pulses and oilseeds are successfully grown by utilizing residual soil moisture and/or post-monsoon rainfall/ supplemental irrigation. The establishment methods included utera, zero-till, reduced-till and conventionally till cropping. An introspection to past research established the importance of system approach for choice of crops and cultivars and management of tillage, nutrient, water and weed. Seed priming of rice-fallow crops ensured better germination and stand establishment under harsh condition. Application of organic nutrient sources (green-manuring, farmyard manure), sulphur (S) and zinc (Zn) has positive direct effect on rice and residual effect on the succeeding crops. Application of nitrogen (N) and phosphorus (P) as diammonium phosphate (DAP) to preceding rice during terminal growth phase and foliar feeding of nutrients were found promising in utera cropping. Use of organic/ green-manure in rice, application of basal fertilizer and foliar feeding improved productivity in zero-minimum- and conventionally-till crops. One or two protective irrigations improved productivity of rice fallow pulses and oilseeds in eastern India and coastal peninsula. Quizalofop ethyl (50 g/ha) or imezethapyr (100 g/ ha) as post-emergence spray provided satisfactory control of grassy weeds. Location-specific constraint analysis, strategic planning based on research findings and policy support would be helpful in greening more rice-fallow areas with pulses and oilseeds, enhancing domestic production, reducing import and saving foreign exchange. Important policy support needed for greening rice-fallows are discussed in the article