Enhanced Potassium Fertilization Improved Rice (Oryza sativa) Yield and Nutrient Uptake in Coastal Saline Soil of Bangladesh

Despite the saline soils of Bangladesh having high potassium (K) availability, the acquisition of K by rice ( Oryza sativa L . ) is unsatisfactory. The study was designed to quantify the performance of rice yield components, macro-nutrient uptake, K + /Na + ratio, and nutrient use efficiency under the influence of improved K fertilization in a salt-affected soil. The salt-tolerant Boro rice cultivar (BRRI-47) was tested with seven different K treatments (0, 20, 40, 60, 80, 100, and 120 kg K ha −1 ) with three replications followed by a complete randomized design (CRD). The results indicated that increasing K levels had a positive influence on most of the growth and yield parameters of rice except plant height, unfilled grain number, and 1000 grain weight. Application of 100 kg K ha −1 raised the grain yield by 49% over control and 19.13% over the present national recommended dose (40 kg K ha −1 ). Straw yield increased by 42% in treatment K 120 and 36% in treatment K 100 over control, respectively. The K + /Na + ratio in plants was observed to be higher when K was applied at higher rates. Additionally, the different K doses improved the nutrient (N, P, K, S) uptake and decreased the internal N and K use efficiencies of rice. It can be summarized that 100 kg ha −1 K fertilization could be effective to improve rice production and nutrient uptake in coastal saline soil of Bangladesh while maintaining a high K + /Na + ratio.