Fate and efficiency of urea based fertilizer N for rice

Abstract

With a view to evaluate the comparative efficacy of different urea modified materials at various doses of N, an experiment was conducted at the Cropping Sytems Research Centre, Karamana during 1985-86. The experiment was laid out in a split plot design with three replications. There were five levels of nitrogen (0, 37.5, 75, 112.5 and 150kg/ha) in the main plots and six types of urea (prilled urea, urea super granules, urease inhibited urea, Neem cake coated urea, Sulphur coated urea and Rock phosphate coated urea) in the sub plots. The rice variety used was Jaya. The abstract of the results are given below. The highest tiller production was observed when USG was applied @ 150 kg N/ha. Application of SCU @ 112.5 kg N/ha, resulted in the production of highest amount of dry matter at harvest. Application of SCU or USG @ 112.5 kg/ha, resulted in the highest N uptake. Nitrogen recovery percentage was highest when NCU or SCU was applied @ 37.5 kg N/ha. Plants supplied with SCU or USG resulted in the production of more number of spikelets/panicle and higher test weight.