Effects of Blended NPS Fertilizer Rates on the Yield Components and the Yield of Bread Wheat Varieties (Triticum aestivum L.)

The use of improper fertilizer type and amount, the cultivation of unimproved, low-yielding varieties and poor soil fertility are among the main obstacles limiting the productivity of wheat in Ethiopia in general and in the study area in particular. A field trial was therefore initiated to evaluate the effects of blended NPS fertilizer rates on the yield components and the yield of bread wheat varieties and to identify economically justifiable amounts of blended NPS fertilizer in the study area. The experiment was set up in RCBD with three replicates in which three bread wheat varieties (Ogolcho, Jalane and Sanate) and five levels of mixed NPS fertilizers (0, 50, 100, 150 and 200 kg ha-1) were assessed in a factorial combination. The results showed that all properties of the bread wheat varieties were significantly (p <0.01) influenced by the main effects of the variety and the NPS fertilizer. The highest (0.43) and the lowest (0.36) harvest index were obtained from 150 kg ha-1 NPS. The interactions of the two main factors only affect the total number of tillers, the number of productive tillers, the aboveground biomass, the grain and straw yield. Similarly, the highest and lowest (11.04 and 1.13) agronomic efficiencies were obtained from the combination of 150 kg NPS ha-1 with the Sanate variety and 50 kg ha-1 with the Jalane variety. The highest profitability (82710 ETB ha-1) and a higher MRR (2305.8%) are obtained from the Sanate variety with an application rate of 150 kg ha-1 NPS. Based on the results of this study, it can be concluded that the application of 150 kg ha-1 NPS and the cultivation of the Sanate variety could be the better choice of the farmers of the study area in order to achieve high yields with higher returns.