PRODUCTIVITY AND ECONOMICS OF RICE (ORYZA-SATIVA)-BASED CROPPING SEQUENCES

A field experiment was conducted during 1987-90 to find out the most s uitable rice (Oryza sativa L.)-based cropping sequence on sandy-loam s oil of north-eastern ghat zone of Orissa under irrigated medium-land s ituation. Amongst different rice-based cropping sequences, rice-potato (Solanum tuberosum L.)- cowpea [Vigna unguiculata (L.) Walp.] recorde d the highest yield on rice-equivalent basis with maximum production e fficiency. Their sequence also achieved the highest energy output with maximum energy input : output ratio. Rice-garden pea (Pisum sativum L . sensu lato)-cowpea sequence secured the highest net return and cost : benefit ratio and was on a par with rice-potato-cowpea system. Inclu sion of cowpea as summer crop in rice-wheat (Triticum aestivum L. emen d. Fiori & Paol.)-cowpea and rice-mustard [Brassica junecea (L.) Czern j. & Cosson]-cowpea sequences not only inhanced the production of rain y and winter crops of both the sequences but also increased the total production on rice-equivalent basis by 2.5 and 2.8 tonnes/ha, net retu rn by Rs 6,065 and Rs 6,871/ha and energy output by 9.32 MJ X 10(3)/ha over rice-wheat-okra (Hibiscus esculentus L.) and rice-mustard-okra s ystems respectively. However, rice-cabbage [Brassica oleracea L. conva r. capitata. (L.) Alef. var. capitata L.]-okra was found superior to r ice-cabbage-cowpea with respect to rice-equivalent yield (2.6 tonnes/h a), net return (Rs 4,062/ha) and energy output (7.87 MJ x 10(3)/ha) du e to poor performance of cowpea as compared to okra after cabbage.