PRODUCTION POTENTIAL AND ENERGY-USE EFFICIENCY OF RICE (ORYZA SATIVA)-BASED CROPPING SYSTEMS

A field experiment was conducted during 1986-88 at Madurai with 5 different rice (Oryza sativa L.)-based cropping systems, 2 fertilizer levels and 2 irrigation regimes. The production potential in terms of rice-yield equivalent was more in groundnut (Arachis hypogaea L.) + blackgram (Phaseolus mungo L.) - rice - sesame (Sesamum indicum L.) sequence. Irrigating the rice crop to 5 cm depth on the day of disappearance of ponded water and irrigating the rainy-season and summer crops at 0.75 and 0.60 irrigation water depth cumulative pan evaporation (IW : CPE) ratios respectively gave highest rice-grain yield equivalence. Recommended level of irrigation and fertilizer NPK based on soil test enabled higher utilization of solar energy.