EFFECT OF BLENDED NPS FERTILIZER RATES ON YIELD COMPONENTS, YIELD, GRAIN QUALITY AND NUTRIENT USE EFFICIENCY OF BREAD WHEAT (Triticum aestivum L.) VARIETIES IN BULE HORA DISTRICT, SOUTHERN OROMIA

Abstract

Bread wheat is one of important food crop in the study area, but its productivity is limited by poor soil fertility. Thus, the study was conducted to investigate the effect of blended NPS fertilizer rates on yield and yield-related traits, nutrient use efficiency and grain quality of bread wheat varieties and assess their economic feasibility. Factorial combination of three bread wheat varieties (Senate, Mandoyu and Local) and six fertilizer rates (0, 50, 100, 150, 200, and 250 kg NPS ha-1) were laid out in Randomized Complete Block Design (RCBD) with three replications. The results showed that days to heading, physiological maturity, spike length, number of tillers per plant, thousand-kernel weight, above-ground biomass yield, straw yield, phosphorus and sulphur recovery and physiological efficiency were significantly influenced by the main effects of wheat varieties and NPS fertilizer rates. On the other hand, plant height, harvest index and grain yield, agronomic efficiency, uptake and recovery efficiency of nitrogen, grain protein content, hectolitre weight and gluten index were affected by the interaction effect of variety and NPS fertilizer rates. The highest grain yield (4306.67 kg ha-1) was obtained from the Senate variety applied with a 150 kgha-1 NPS rate under supplemental nitrogen. The highest nitrogen use efficiency was achieved with 200 kg ha-1, while the lowest efficiency was achieved with 0 kg NPS fertilizer. The highest net benefit (162,620 ETB) with acceptable MRR (1039.47%) was achieved from Senate variety at 150 kg NPS ha-1 supplied with supplemental nitrogen. Thus, it can be concluded that the Senate variety supplied with 150 kg NPS ha-1 of NPS supplemented with 46% nitrogen proved to be superior in grain yield as well as economic advantage and is temporarily recommended for use. However, as this study was done for one season at one location, the experiment has to be repeated over years to reach conclusive recommendations