Rice-Zero Tillage Potato-Green Gram and Conservation Agriculture Enable Sustainable Intensification in the Coastal Region

Rice-fallow and rice-rice are important cropping systems in India next to rice-wheat. Rice-fallow system faces critical resource shortages such as irrigation water and encounters salinity whereas, rice-rice system is heavily dependent on extensive non-renewable natural resources with poor resource use efficiency and unsustainability. Sustainable cropping intensification options through on-station and on-farm research have been developed under a multi-institutional project funded by the Australian Centre for International Agricultural Research (ACIAR) during 2015-2022 to address these challenges. The results showed that rice followed by zero tillage planting of potato with paddy straw mulching (ZTPSM), and the rice-potato ZTPSM-green gram cropping pattern are the most promising systems compared to conventional rice-rice rotation. System rice equivalent yield increased from 11.7 t ha-1 in rice-rice to 20.2 t ha-1 in rice-potato ZTPSM-green gram (R-PZTPSM-GM). The soil salinity (ECe) diminished to <3.6 dS m-1 due to ZTPSM from 5.29-6.36 dS m-1 under conventional practice. There is scope to sustainably intensify the rice-fallow lands to at least 200% cropping intensity from the current 150% with additional net returns of ₹ 0.95 Lakhs ha-1. In addition, the R-PZTPSM-GM system has a lower environmental footprint due to lower irrigation water (0.31 m3 kg-1 rice-eq) requirement and lower carbon (10.1 t CO2-eq ha-1) emissions intensity than rice-rice system (1.19 m3 kg-1 rice and 30.5 t CO2-eq ha-1).