Abstract

The purpose of the present study was to evaluate the effect of potassium on growth and yield of rice and to find out the best suited scheme/timing of potassium fertilizer application for rice crop. With this regard, pot experiments with Shwe Thwe Yin rice variety were conducted at the screen house of Department of Soil and Water Science, Yezin Agricultural University during the dry and wet seasons of 2014. In this investigation, a recommended dose of potassium fertilizer (37 kg ha⁻¹) was tested in 7 different treatments i.e. T1 (all potash applied as basal), T2 (all potash applied at 25 DAT), T3 (all potash applied at 45 DAT), T4 (½ potash applied as basal and remaining ½ at 25 DAT), T5 (½ potash applied as basal and remaining ½ at 45 DAT), T6 (½ potash applied at 25 DAT and remaining ½ at 45 DAT), and T7 (1/3 potash applied as basal, 1/3 at 25 DAT and remaining 1/3 at 45 DAT) and no potash application was used as T8 (Control). Based on the two strong investigations, yield, yield components and nutrient use efficiency were responded to different application time of potassium fertilizer. T6 (½ potash applied at 25 DAT and remaining ½ at 45 DAT) and T2 (all potash applied at 25 DAT) produced more grain yield in both seasons. Least value of yield was achieved in the treatment T8 (Control) and T1 (all potash applied as basal) ranked at second. The maximum partial factor productivity of potassium (PFPK) was observed from T6 (½ potash applied at 25 DAT and remaining ½ at 45 DAT) and T2 (all potash applied at 25 DAT) among the treatments in both seasons. According to the results of this study, basal application of potash (traditional method) may be replaced by a late application of potash at 25 DAT (maximum tillering stage) and split application of potash in two splits ½ at 25 DAT and remaining ½ at 45 DAT may be promoted for getting maximum benefit.