Optimizing dose and timing of potassium application in enhancement of potassium uptake and yield in rice

Abstract

The dose and time of fertilizer application considerably influences the crop response to fertilizer. Applying K as basal is the common practice which has not significantly augmented rice yield under modern intensive agriculture. Development of practices to improve the efficiency of nutrients requires an understanding of the fate of the applied nutrient and their effect on crop production. To find the scope of increased dose of K fertilizer with varying time of application in rice crop with respect to K concentration, K uptake, biomass accumulation and yield; an experiment was conducted during year 2017-18 in north eastern plains of India. This experiment was laid out in split plot design with three levels of potassium K1 (40 kgha-1), K2 (60 kgha-1) and K3 (80 kgha-1) and four different time of application i.e. S1 (basal), S2 (50% basal + 50% at max. tillering), S3 (50% basal + 25% at max. tillering + 25% at PI) and S4 (75% as basal + 1% spray at maximum tillering and PI). Results revealed that with increase K fertilizer dose upto 80 kgha-1 there was significant effect on biomass accumulation (1871.9 g m-2 at harvest), K concentration (0.61% in grain and 1.70% in straw), uptake (19.3 kg ha-1 in grain & 83.4 kg ha-1 in straw) and grain yield and straw yield (4999 kg ha-1 and 8488 kg ha-1 , respectively). Split application of K fertilizer was found beneficial with S3 (50% basal + 25% at max. tillering + 25% at PI) showed better crop performance and was found at par with slit including spray application of K fertilizer S4 (75% as basal + 1% spray at maximum tillering and PI). Increased K concentration also aided in the efficient utilization of other plant essential nutrients (N & P) thereby positive effect on yield was found.