EFFECT OF SUBSTITUTION OF FERTILIZER NITROGEN WITH SUBABOOL (LEUCAENA-LEUCOCEPHALA) LEAVES ON GROWTH AND YIELD OF RAIN-FED SORGHUM (SORGHUM-BICOLOR) IN AN ALFISOL

An experiment on substitution of fertilizer nitrogen with green leaves of subabool [Leucaena leucocephala (Lam.) de Wit] was conducted for 2 years under rainfed conditions with sorghum [Sorghum bicolor (L.) Moench]. Grain and fodder yields of sorghum increased by 59 and 74% respectively with the application of 40 kg N/ha compared with the control. Application of N as subabool leaves equivalent to 30 kg N/ha (75%) along with 10 kg N/ha as urea gave significantly higher grain and fodder yields than application of 40 kg N/ha as urea alone when the rainfall distribution was uneven. With even rainfall distribution, however, the differences were not significant. Fertilizer N could be effectively substituted by subabool leaves to the extent of 50-75% of the recommended N for sorghum under rainfed condition.