Potassium Fertilization and Application Time for Wheat Yield Improvement in Cambisols of Enderta Districts, South Eastern, Tigray

Recently the government of Ethiopia has introduced potassium as fertilizer through the introduction of various K containing blended fertilizers. However, the optimum application rate and time of application on specific crop and soil type has not been studied yet. So, a field experiment was conducted to determine the optimum rate of potassium and its application time for wheat yield and yield components in Cambisols of Enderta district South Eastern zone of Tigray. The experiment was laid out in Randomized Complete Block Design with 4 levels of potassium (0, 40, 60 and 80 of K2O kg/ha) with and without split application including control in three replications. Results depicted that except harvest index all the yield and yield components of wheat were influenced by potassium fertilization. Moreover, split application of K significantly affected the yield and yield components of wheat as compared to single application of full dose of K. In line with this, the highest grain and straw yields of wheat were obtained at 80 kg/ha K2O levels and statistically similar with the split application levels of 40 and 60 kg/ha K2O. This implies that the 40 kg/ha K2O at split application is economically feasible (optimum) level of K for wheat production in the Cambisols of the area studied. The highest agronomic efficiency and partial factor productivity were also obtained at the level of 40 kg/ha K2O in split forms. Hence, potassium fertilization is important and should be applied in split methods rather than at full single dose at planting for increasing wheat yield and improving agronomic efficiency and partial factor productivity in the Cambisols of Enderta districts.