Effect of potassic fertilizer application on available potassium at different growth stages of paddy in calcareous soil of North Bihar

A field experiment was conducted in calcareous soil of North Bihar which was medium in available K. The experiment was carried out in split-plot design with two paddy varieties viz., Inbred and Hybrid in main plot and six combinations of potassium management viz., control, NP(-K), NP + K (100% basal), NP + K (50% as basal + 50% at tillering), NP + K (50% as basal + 50% at panicle) and NP + K (50% as basal + 25% at tillering + 25% at panicle) in sub-plot during Kharif, 2017 at Crop Research Farm, RPCAU, Pusa, Samastipur. The availability of K in the soil at different growth stages of paddy was found to improve with split applications of potassium over basal application. At tillering stage, available K was highest in the plots receiving split applications of K i.e. 50% as basal + 50% at tillering while at panicle and milking stage, available K was highest in the plots with split application of K i.e. 50% as basal + 50% as panicle. At maturity, it was highest in the plots with three split applications of K (50% as basal + 25% at tillering + 25% at panicle).