Effect of Nutrient Omission on Grain Yield and Yield Components of Maize (Zea mays L.) at Kersa District, Jimma Zone, Southwestern Ethiopia

Application of fertilizer is the most effective means to increase nutrient uptake in crop plants and improve yields and quality. A field experiment was conducted with an objective to identify which of macronutrients N, P and K are limiting maize grain and yield components in the study area during 2017/18 cropping season. The experiment was laid out in a completely randomized block design with six treatments replicated across six farmers’ fields in Kersa district, Jimma zone, south western Ethiopia. The trial consisted of six treatments, unfertilized control, PK, NK, NP, NPK and NPK+. Maize grain yield was the highest for the NPK treatment followed by NPK+ treatment but lowest for the unfertilized control and N omitted plots. In absence of N, P, and K maize grain yields were significantly lower compared to that of NPK and NPK+ treatments. Among the different treatments, NPK gave the highest grain yield (9185 kg ha-1), while the control treatment gave the lowest grain yield (1861.3 kg ha-1). Grain yield levels obtained for different fertilizer treatments were ranked as NPK>NPK+>NP>PK>NK, illustrating that N deficiency was the most yield limiting nutrient followed by P and K in order. Therefore, NPK is the most suitable balanced fertilizers as application of secondary and micronutrients did not further enhance grain yield in the study area.