Optimum Determination of NPSB Fertilizer Rates on Bread Wheat (Triticum asetivum L.) Varieties

The field experiment was conducted at Degam district during main cropping season to investigate the response of bread wheat varieties to NPSB fertilizer rates and identify its economic benefit. Factorial combination of three improved bread wheat varieties (Danda’a, Hidase and Kakaba) and six fertilizer rates [Control, 50, 100, 150, 200 kg ha-1 NPSB fertilizer each supplemented with 92 kg N ha-1 and 64/20 kg NP ha-1 (Blanket recommendation) were laid out in randomized complete block design with three replications. The highest NKS (54.9), AGBM (13.8 tons ha-1), SY (9.4 tons ha-1) and GY (4549kg ha-1) were recorded from 200 kg NPSB fertilizer. Among the varieties the highest NKS (54.3) from Danda’a, TKW (49.3 g) and GY (3351kg ha-1) were recorded from Hidase variety. Variety Kakaba score the highest PH (102.5 cm) and PNT (5 per plant) with combination of 200 kg and 150 kg NPSB fertilizer respectively and reached days to heading and maturity earlier than Danda’a and Hidase. In general, the economic feasibility of the fertilizer over varieties combination indicated that application of 200 kg NPSB ha-1to all varieties Hidase, Danda’a and Kakaba resulted in maximum marginal rates of return 640.14 %, 604.81% and 481.47%, with a net benefit of 97993, 88596, and 82996 ETB respectively. Although, application of 200 kg NPSB ha-1 led to the highest MRR for the Hidase variety as compared to all other treatments and with about a total of 9397 ETB net benefit increment. Therefore, application of 200 kg of NPSB in supplement of 92 kg N ha-1 fertilizer with Hidase variety was the best producing economically profitable with acceptable grain yield.