Enhancing Post-Harvest Soil Fertility in Wheat Fields via Integrated Zinc, Sulfur, and Vermicompost Strategies

A two-year field trial was conducted at the Agricultural Research Farm of R.B.S. College, Bichpuri (Agra), during the 2021–22 and 2022–23 rabi seasons to evaluate the effects of vermicompost and mineral fertilizers on post-harvest soil properties under wheat cultivation in alluvial soils. The experiment followed a randomized complete block design with three vermicompost rates (0, 2.5, and 5.0 t ha⁻¹) and four fertilizer treatments (control, 40 kg S ha⁻¹, 5 kg Zn ha⁻¹, and 40 kg S + 5 kg Zn ha⁻¹). Soil samples collected after harvest were analyzed for pH, electrical conductivity (EC), soil organic carbon (SOC), and available macronutrients (N, P, K) and micronutrients (S, Zn). Results demonstrated that application of vermicompost at 5.0 t ha⁻¹ significantly enhanced soil fertility parameters compared to the unfertilized control, with increases of 12% in SOC, 18% in available N, 15% in available P, 10% in available K, 20% in available S, and 22% in available Zn. Similarly, the combined S + Zn treatment (40 kg S + 5 kg Zn ha⁻¹) markedly improved soil nutrient status, elevating SOC by 8%, available N by 12%, P by 10%, K by 7%, S by 28%, and Zn by 30% over the control. The synergistic application of 5.0 t ha⁻¹ vermicompost with 40 kg S + 5 kg Zn ha⁻¹ showed the most pronounced effect, further boosting SOC and nutrient availability. These findings indicate that integrating organic and mineral nutrient sources can sustainably rejuvenate alluvial soils after wheat harvest, thereby supporting subsequent crop productivity and long-term soil health.