POTASSIUM FERTILIZATION MAY IMPROVE STEM STRENGTH AND YIELD OF BASMATI RICE GROWN ON NITROGEN-FERTILIZED SOILS

摘要

Imbalance use of fertilizers is one of the important factors for lodging of rice leading to paddy-yield reduction. Potassium (K) deficiency may be one of the contributing factors in this regard. Present study was conducted to assess the decrease in lodging losses due to use of K fertilizer in the presence of nitrogen by determining various factors contributing to stem strength. Two levels of K, one with deficient (K-d) while other with recommended (K-r) K and three levels of N i.e. deficient (N-d), half of recommended (N-hr) and recommended (N-r) N were applied along with recommended dose of phosphorus and zinc to two fine-grain rice cultivars i.e. Super basmati and Basmati 515. The experiment was laid out in randomized complete block design in factorial arrangement with four replicates. Application of K fertilizer significantly improved K concentration in rice stem, and paddy yield of Basmati rice. Furthermore, K fertilization improved plant parameters such as basal internode space, cellulose content and stem-fiber contents. Increase in silicon content in stem due to application of K was also observed, which may also contribute to stem strength against environmental stresses. The present study suggests further work to understand the physiological and biochemical mechanisms contributing to stem strength in response to K fertilization.