Optimization of nitrogen and potassium levels and time of application for productivity enhancement of rice in southern dry zone of Karnataka

A field experiment was conducted on a sandy clay loam soil at College of Agriculture, Vishweshwaraiah Canal Farm, Mandya during kharif 2019 and kharif 2020 to study the growth and yield of semi dry rice influenced by combination of nitrogen and potassium doses and time of application. The experiment was laid out in split-plot design replicated thrice, the treatments comprised of 2 nutrient doses (100% RDNK and 125% RDNK) assigned to main plots and seven time of application different split application in sub plots. The results of indicated that application of 125% RDNK registered higher number of tillers and panicles (340.60 and 298.31/m2), filled grains/ panicle (86.3), 1,000-grain weight (21.04 g), grain and straw yields (5,515 and 7,408 kg/ha respectively) than the application of 100% RDNK and application of N at 4 splits as, 25% each at sowing, early tillering (ET), tillering (T) and panicle initiation (PI), K at 2 splits (50% at basal and 50% at panicle initiation (PI). Application of 125% recommended doses of nitrogen and potassium registered higher number of tillers and panicles (345.42 and 302.17/m2), filled grains/panicle (133.14), 1,000-grain weight (21.14 g), grain and straw yields (5,567 and 7,541 kg/ha respectively) than the application of 100% RDNK over other splits.