Effects of Blended Fertilizer (NPS) Rates on Yield and Yield Components of Wheat (Triticum Aestivum L.) Varieties in Emba-Alaje District, Tigray, Ethiopia

Abstract

This study was conducted to determine the optimum blended NPS fertilizer rate that maximizes yield and economic return for three bread wheat (Triticum aestivum L.) varieties in Emba-Alaje District, Tigray, Ethiopia. Wheat is a major staple crop in the area; however, productivity remains low mainly due to poor soil fertility and inappropriate fertilizer use. A field experiment was carried out during the 2024 main cropping season under rainfed conditions using a randomized complete block design (RCBD) with three replications. Treatments consisted of three bread wheat varieties (Boru, Wane, and Kingbird) and four blended NPS fertilizer rates (0, 62.5, 125, and 187.5 kg ha⁻¹) arranged factorially. Growth parameters (plant height, spike length, kernels per spike, and thousand-kernel weight) and yield components (grain yield, straw yield, total biomass yield, and harvest index) were recorded. Data were analyzed using ANOVA in GenStat (18th edition), and treatment means were separated using LSD at 5% significance level. NPS fertilizer rate significantly affected most measured traits. The highest plant height (68.76 cm) and grain yield (3,796 kg ha⁻¹) were obtained at 125 kg ha⁻¹ NPS, whereas the control treatment produced the lowest values (47.13 cm plant height and 1,651 kg ha⁻¹ grain yield). The Wane variety exhibited relatively early maturity (114.7 days) and the highest harvest index (47.3%) when fertilized with 125 and 62.5 kg ha⁻¹ NPS, respectively, which is advantageous under moisture-limited conditions. Partial budget analysis following CIMMYT (1988) indicated that Boru combined with 125 kg ha⁻¹ NPS produced the highest net benefit (302,489 ETB ha⁻¹) with a marginal rate of return of 1,465.024%. Therefore, application of 125 kg ha⁻¹ blended NPS fertilizer with Boru (and Wane where early maturity is desired) is recommended to improve wheat productivity and profitability in Emba-Alaje District and similar agro-ecologies.