Productivity of rice (Oryza sativa) as influenced by crop diversification in wheat (Triticum aestivum)-rice cropping system on Mollisols of foothillsof Himalayas

A field experiment was conducted during 1996-97 and 1397-98 an clay-loam so il at Pantnagar to identify the appropriate crop sequence for higher produc tivity of rainy season rice (Oryza sativa L.). The productivity of rice was measured in 10 crop Sequences, viz wheat (Triticum aestivum L. emend. Fior i-and Paol.)- rice, chickpea (Cicer arietinum L.) - rice, lentil (Lens culi naris L.)- rice, pea (Pisum sativum L.) - rice, wheat-mung bean (Phaseolus radiatus L.) green manure-rice, wheat-sesbania (Sesbania aculeata L.) green manure-rice, wheat-maize (Zea mays L.) +cowpea (Vigna unguiculata it walp. ) fodder - rice, chickpea - maize+cowpea fodder - rice, lentil - maize+cowp ea fodder - rice and pea - maize+cowpea fodder - rice. Compared with wheat- rice sequence the productivity, of rice was significantly higher under whea t-mung bean (green manure)-rice and wheat-sesbania (green manure)rice seque nces during both the year. On an average green manuring with mung bean or s esbania resulted in 18.39 and 13.64% increase in rice grain yield than unde r wheat-rice sequence (5.50 tonnes/ha). Growth parameters, viz plant height and dry-matter accumulation/hill and yield attributes, viz number of produ ctive shoots, panicle length, number of fertile spikelets/panicle, grain we ight/panicle and 1 000-grain weight were significantly higher under green m t sequences. Among other sequences chickpea-rice proved superior to wheat-r ice with respect to yield and growth parameters.