ASSESSMENT OF NITROGEN AND POTASSIUM FERTILIZATION ON RICE YIELD IN MAUBIN TOWNSHIP

To assess the effect of different levels of nitrogen fertilization with and without potassium fertilizer on the yield and yield components as well as agronomic efficiency of Thee Htat Yin rice variety, the field experiments were conducted in Maubin township during 2015 and 2016 of dry season. Four levels of nitrogen and potassium fertilizer treatments with four replications included in the experiment using RCB experimental design. The eight treatments of experiment were control (no fertilizer), P (only phosphorus), N1P (58 kg N ha-1), N1PK1 (58 kg N ha-1 and 31 kg K ha-1), N2P (116 kg N ha-1), N2PK2 (116 kg N ha-1 and 63 kg K ha-1), N3P (174 kg N ha-1) and N3PK3 (174 kg N ha-1 and 94 kg K ha-1). The routine rate of phosphorus fertilizer (12 kg P ha-1) was applied in all treatments except control. According to the experimental results, different rates of N and K fertilizer application had significant effects on plant height, number of tillers, number of panicles, number of spikelets and grain yield. The grain yield and yield components of rice responded to N fertilizer application. However, the higher values of these results were observed to N fertilizer application. However, the higher values of these results were observed from balanced fertilization of N and K as compared to N without K fertilizer application treatments in both seasons. The highest grain yield obtained from N2PK2, and thus fertilizer level of 116 kg N ha-1 and 63 kg K ha-1 could be optimum for achieving higher grain yield. Relative to treatments without K, nitrogen use efficiency (NUE) of balancing N and K fertilizer treatments showed an increase in ratio ranging from 6.7% to 38.25 % for first season and from 10.83 % to 28.57% for second season experiment. Yield increment by the application of N fertilizer with K indicated the need of K application in rice cultivation related to yield response. Higher fertilizer rate beyond certain level may not increase the grain yield of rice. Application of N and K would prevent soil K mining to sustain soil productivity and crop yield in the long ru