Green Leaf Manure of Leucaena leucocephala Lam. De Wit. And Gliricidia sepium (Jacq.) Steud as Complete Substitute for N to Rice (Oryza sativa L.) in Acid Sulphate Soil.

Abstract

Three levels of nitrogen at 60, 90 and 120 kg/ha from green leaf manure of Leucaena leucocephala and Gliricidia sepium were compared with nitrogen at 60 kg/ha from urea and control (without nitrogen) for growing rice (Oryza sativa), variety Suphan Buri 90 under irrigated condition at Asian Institute of Technology, Bangkok, Thailand during January to June, 1995. The purpose of conducting the experiment was to sort out the effect of green leaf manure on yield components of rice as well as to find out the change in plant N content, residual impact of green leaf manure on soil N content and pH and to know their ability to completely substitute chemical N to rice. The results revealed that application of green leaf manure N at 120 kg/ha from both of Leucaena and Gliricidia produced yield and agronomical components of rice similar to that obtained from N at 60 kg/ha from urea. The result also concluded that green leaf manure N at 120 kg/ha could completely substitute N at 60 kg/ha from urea and green leaf manure coulf be used in the form of top dressing. There was significant increase in yields off rice due to the use of green leaf manure. However, the increase in grain yield over vontrol treatment in green leaf manure treated plots was from 19-49%. There was positive relation with grain yield in components of effective tillers per hill, number of filled grains per panicle, 1000 grain weight, number of panicle per square meter, biomass yield and straw yield.