Effect of Phosphorus and Zinc Fertilization on Yield and Nutrient Use Efficiency of Wheat (Triticum aestivum L.) in Tigray Highlands of Northern Ethiopia

Wheat is a vital staple crop addressing significant nutritional needs. However, it faces micronutrient deficiencies in Ethiopia, prompting the use of balanced nutrient fertilizers to obtain better yields, nutrient concentration, and nutritional quality. This study investigated the effect of different P and Zn fertilizer combinations on wheat yield and nutrient use efficiency across three locations in Tigray, Ethiopia. A randomized complete block design (RCBD) was used with four P levels (0, 10, 20, and 30 kg P ha⁻1), and three Zn levels (0, 5, and 10 kg Zn ha⁻1) in three replications. A balanced application of P and Zn fertilizers significantly increased wheat grain and biomass yields, while applying higher rates of both nutrients (i.e., 30 kg P ha⁻1 and 10 kg Zn ha⁻1) reduced yields. The combined application of 20 kg P ha⁻1 and 5 kg Zn ha⁻1 achieved the best yield, which also improved Zn use efficiency. Increasing Zn application (from 5 to 10 kg Zn ha⁻1) while reducing P (from 20 to 10 kg P ha⁻1) enhanced Zn concentration in wheat grain. These findings highlight the importance of carefully managing P and Zn fertilization to optimize grain yield and Zn bioavailability, contributing to improved food security in diverse agro-climatic conditions.