INTEGRATED RICE STRAW UREA MANAGEMENT FOR TRANSPLANTED RICE

Four field experiments were conducted over the 1992 and 1993 seasons ( southwest monsoon seasons, June-October) in the warm subhumid tropical region on the west coast of the Maharashtra State, India. The objecti ve was to investigate the effect of recycling limited amounts of rice straw (RS) (as a source of K and Si) integrated with the use of prille d urea (PU) and urea briquettes (UB) at 60 kg N/ha on the growth and y ield of rainfed transplanted rice (Oryza sativa L.). The management pr actice, consisting of basal incorporation of RS (2 t/ha) integrated wi th deep placement of UB (one 2.1-g UB/4 hills) immediately after trans planting using a modified 20 x 20 cm spacing, produced a significantly higher grain yield (average increase of 1.3 t/ha) and straw yield (av erage increase of 1.1 t/ha) than did the RS practice integrated with t wo equal split applications of PU at the same N rate and hill spacing. The additional yields were attributed to the increase of total and pr oductive tillers/m(2) and panicle weight. The results indicate the pot ential of the integrated RS-UB management for increasing yields of rai nfed transplanted rice in the warm subhumid tropical zone.