Optimum K Fertilizer Level for Growth and Yield of Wheat (Triticum aestivum) in Cambisols of Northern Ethiopia

A field experiment was conducted in summer to evaluate the response of wheat to different potassium fertilizer rates on Cambisols of Tigray, Northern Ethiopia. The experiments were laid out in Randomized Complete Block Design replicated three times with 4 levels of potassium (0, 30, 60, 90, K2O kg/ha). Data on yield and yield components of wheat were collected and regression, as well as variance analyses, were done. Results depicted that wheat plant height, spike length, harvest index and 1000 seed weight were all not significantly influenced by K fertilizer rates. However, biological and grain yield of wheat was significantly influenced by potassium levels. Hence, the highest biological yield (straw + grain) and grain yield of wheat were obtained at the rate of 90 K2O kg/ha. Besides, the highest N and K uptakes by wheat were found at 60 K2O kg/ha. Similarly, the highest apparent K recovery and agronomic use efficiency were found at 30 K2O kg/ha. Hence, it can be concluded that potassium fertilization is important and the levels in the blended formula did not meet the wheat requirement in the soil reference group. Thus, this study recommends application of potassium.