Energy efficiency, productivity and profitability of rice farming using Sesbania as green manure-cum-cover crop

Two field experiments were conducted at the Research Farm of ICAR-Indian Institute of Water Management, Mendhasal, Odisha with wet season rice. The objective of the first experiment was to compare the effect of inorganic fertilizers (IF) with the integrated nutrient management (INM) using in situ green manure Sesbania and complimentary dose of IF on rice yield, energy use, economics and residual soil fertility. In the second experiment, the IF was compared with the organic nutrient management (ONM) using in situ green manure Sesbania and vermicompost. The results of the first experiment revealed that grain and straw yields of rice were similar with the INM and IF. However, the INM helped in reducing energy input (24%), improving energy efficiency (35%) and net return (20%). Soil organic C, available N and P contents increased significantly by 14%, 8% and 53%, respectively, for the INM at the end of 3 years. The results of the second experiment revealed that the ONM registered rice grain yield reduction by 8% but increased net return (8%) due to a higher premium of INR 1750 (US $ 26.21) t −1 paddy grain. The ONM treatment reduced energy input (39%) and enhanced energy efficiency (57%) as compared to the IF. Soil organic C, available N and P contents increased by 23%, 39% and 12%, respectively, for the ONM at the end of 3 years. Thus, the practice of ONM or INM using Sesbania green manure-cum-cover crop saved energy and fertilizer, and maintained soil fertility.