Abstract

An investigation was carried out at Agricultural College, Madurai, Tamil Nadu. to study the direct and residual effects of organic manures integrated with inorganic N levels and plant densities on the production potential of rice-rice cropping system. Application of cattle manure (FYM or sheep penning) had pronounced direct effect on rice grain yield (7.92 and 7.86 t ha", respectively) as against 7.41 t ha with green manure (Sesbania rostrata) application in kharif season, and residual effect with 6.01 and 5.71 t ha respectively, in rabi season. Though the plant densities (8.33 and 6.67 lakh hills ha 1) did not affect the grain yield significantly in Kharif, low plant density recorded higher grain yield (5.61 t ha') in rabi season. The most economical level of N was found to be 160 kg ha for both the seasons.

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