Influence of diversification on productivity, profitability and efficiency of rice (Oryza sativa)-based cropping systems under irrigated condition

A long-term field experiment was conducted during 200607 to 201213 at Bhubaneswar, Odisha under irri- gated medium land condition, to evaluate the production potential and economics of 10 rice (Oryza sativa L.)- based cropping systems. Ricetomato (Solanum lycopersicum L.)cowpea [Vigna unguiculata (L.) Walp.] and ricemaize (Zea mays L.)okra [Abelmoschus esculentus (L.) Moench] cropping systems recorded significantly higher rice-equivalent yield (24.24 and 22.75 t/ha respectively) than other systems evaluated, the relative produc- tion efficiency being 140 and 122% over the existing ricegroundnut (Arachis hypogaea L.) system. The rice groundnut system recorded the least rice-equivalent yield (9.75 t/ha). Land-use efficiency (LUE) of ricetomato cowpea system was the highest (85.8%), followed by that of ricegroundnutcucumber (Cucumis sativus L.) (83.8%) and riceFrench bean (Phaseolus vulgaris L.)sesame (Sesamum indicum L.) (81.9%). Ricetomato cowpea gave the highest gross and net returns of 277,276 and 166,776/ha respectively, followed by rice maizeokra system with gross and net returns of 256,210 and 150,210/ha respectively. These two systems also recorded higher benefit: cost ratio (2.51 and 2.42) with 257 and 222% relative economic efficiency over the rice groundnut system. The cropping systems which included the legumes like groundnut, cowpea and French bean improved soil organic carbon content by 15.9 to 21.7% over the initial value of 0.69%. The cropping systems hav- ing cowpea as a summer crop increased the available N content by 8.5 to 13.8%; however, the available P and K content in soil decreased in all the systems after completion of 7 cropping cycles, though the depletion in K was more pronounced than that of P.