Time of application of potassium on nitrogen utilization and yield of dwarf indica rice varieties

Abstract

A pot culture trial was conducted using the soil belonging to the order Entisols collected from Pattambi and Trivandrum districts of Kerala. Skipping basal application of muriate of potash along with urea and application of potassic fertilizer at maximum tillering and reproductive stages enhanced grain yield for the medium duration variety Jaya by increasing number of earheads, thousand grain weight and increasing the percentage of fertile grains per panicle. Skipping of potassic fertilizers as basal dose increased soil availability of NHJon nitrogen, the most important from of nitrogen utilized by submerged rice. Initial growth stage was considered as one of the most efficient periods of utilization of nitrogen by rice. For a short duration variety like Triveni 1 7.5 kg K20/ha was found sufficient for obtaining maximum yield. A small basal dose of potassic fertilizers was found required for short duration varieties for obtaining maximum yield.