Abstract

                                Field experiments were conducted in clay loam soils of Cauvery delta to evaluate the efficiency of different N sources on rice during kuruvai and thaladi seasons of 1984 and 1985. Application of lac coated urea was beneficial in recording higher grain yield, N use efficiency as well as N uptake by the crop over ordinary urea during kuruvai season. Application of green manure during thaladi season needed higher dose of fertilizer N at planting to get higher yield of rice. Application of Urea super granule recorded the highest N use efficiency during thaladi season. The uptake of N by the crop was higher with the use of urea super granule, lac coated urea as well as green manure + urea.

Key words : Nitrogen sources, N use efficiency, N uptake, Rice.