Response of Maize (Zea mays L.) Varieties to Potash Fertilizer Rates Under Irrigation Condition in Northern Ethiopia

Response of three maize varieties (Local/Berihu, Melkassa I and Katumani) to four rates (0, 50, 100 & 150kg/ha) of Potash fertilizer was examined under irrigated condition. The result of the physic-chemical analysis of the soil from the test plots has shown that the soil is potassium deficient (0.106 cmol(+)/kg). Application of the potash fertilizer (50kg/ha K2O) has brought about a significant difference (P<0.05) in yield and yield components namely thousand grain weight, grain number per cob, grain yield per plant, grain yield per hectare and total above ground biomass/ha. But the application of the potash fertilizer beyond 50kg/ha has no significant effect on maize yield and yield components. Melkassa I and Katumani were found to be more responsive to this fertilizer rate than the local variety. Therefore, optimum rate for application of potash fertilizer in the study area is 50kg K2O/ha above which amount of fertilizer added was not agronomically and economically efficient. Keywords: Maize varieties, Potash fertilizer, irrigatio