ENERGY INPUT-OUTPUT RELATIONSHIP OF CROPPING SYSTEMS

A field experiment was conducted during 1983-90 at Ranchi, to study th e energetics of 4 cropping systems, viz maize (Zea mays L.) - wheat (T riticum aestivum L. emend. Fiori & Paol.), soybean [Glysine max (L.) M err.] - wheat, rice (Oryza sativa L.) - wheat and groundnut (Arachis h ypogaea L.) - wheat. Maize produced significantly higher grain and tot al biomass energy (34 332 and 130 394 MJ/ha respectively) than the oth er rainy season (kharif crops. Wheat grown in sequence after soybean o r groundnut produced higher energy from grain and total biomass than a fter maize or rice. Among cropping systems, groundnut-wheat sequence w as most efficient in energy production through grain (321 MJ/ha/ day), followed by maize-wheat (318 MJ/ha/day). But in terms of total biomas s, maize-wheat sequence was more efficient (923 MJ/ha/day), followed b y groundnut-wheat (609 MJ/ha/day).