Enhancing maize yield and zinc uptake through foliar application of zinc sulfate in calcareous soil of Peshawar, Pakistan

Zinc deficiency in maize plants is a common problem, particularly in calcareous soils with pH above 7. This study aimed to investigate the impact of zinc sulfate (ZnSO4) applied in different forms (foliar and soil application) and concentrations on maize yield, zinc uptake, and nutrient use efficiency (NUE) in calcareous soil. The results demonstrated that zinc application significantly increased maize yield, zinc uptake, NUE, and the uptake of Nitrogen, Phosphorus, and Potassium. Foliar application of ZnSO4 was more effective than soil application in enhancing zinc uptake, with the highest uptake observed in plants treated with 1.5% ZnSO4 foliar spray. Additionally, zinc application increased zinc content in grains and surface soil, with the highest zinc content in grains found in plants treated with 1.5% ZnSO4 foliar spray and the highest zinc content in surface soil observed in plants treated with 10 kg ha-1 ZnSO4 soil application. These findings suggested that foliar application of ZnSO4 is an effective strategy for improving zinc uptake and grain zinc content in maize plants grown in calcareous soils.