Effect of Farmyard Manure, Zn and Fe on Soil Nutrients and Chemical Status in a Pearl Millet–Chickpea Cropping System

A field trial on the pearl millet–chickpea cropping sequence was conducted during the Kharif and Rabi seasons of 2023–24 and 2024–25 at the Agronomy Farm, B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat, to study the effect of FYM, zinc, and iron on soil chemical properties. The experimental soil was loamy sand (“Goradu” soil), slightly alkaline (pH 7.94), normal in salinity (EC 0.18 dS/m), low in organic carbon (0.32%) and available nitrogen, medium in available phosphorus and potassium, and adequate in zinc and iron The experiment, laid out in a factorial randomized block design with three replications, comprised two levels of FYM (0 and 10 t/ha), three levels of zinc (0, 12.5, and 25 kg/ha as ZnSO4) and three levels of iron (0, 25, and 50 kg/ha as FeSO4), with treatments applied to pearl millet and residual effects studied in chickpea. Application of FYM (10 t/ha), ZnSO4 (25 kg/ha), and FeSO4 (50 kg/ha) had no significant effect on soil pH, EC and organic carbon (OC) after chickpea harvest in either year or on a pooled basis. However, these treatments increased available N, P2O5, K2O, Zn and Fe in the soil. All zinc fractions (water-soluble plus exchangeable, carbonate-bound, Fe/Mn oxides-bound, organically bound, total Zn and residual Zn) were enhanced by FYM and ZnSO4 application, while all iron fractions (water-soluble plus exchangeable, carbonate-bound, Fe/Mn oxides-bound, organically bound, total Fe and residual Fe) were improved with FYM and FeSO4 application. The results demonstrate that integrated nutrient management using FYM, zinc and iron can improve soil nutrient status and micronutrient fractions in loamy sand soils under a pearl millet–chickpea system.