Vol. 9, Special Issue 11, Part B (2025)

Restoring soil fertility in farming systems is essential to sustain crop productivity. Thus, the present study was conducted to assess the residual effect of the combined application of humic acid and inorganic nutrients on growth parameters and yield of wheat under the rice-wheat cropping system in the western plain zone of Uttar Pradesh. The treatments applied in the present study included: T₁: control, T₂: 75% recommended dose of nitrogen (RDN), T₃: 100% RDN, T₄: humic acid (@10 kg ha⁻¹), T₅: humic acid (@20 kg ha⁻¹), T₆: humic acid (@30 kg ha⁻¹), T₇: 75% RDN + humic acid (@10 kg ha⁻¹), T₈: 75% RDN + humic acid (@20 kg ha⁻¹), T₉: 75% RDN + humic acid (@30 kg ha⁻¹), T₁₀: 100% RDN + humic acid (@10 kg ha⁻¹), T₁₁: 100% RDN + humic acid (@20 kg ha⁻¹), T₁₂: 100% RDN + humic acid (@30 kg ha⁻¹). The residual effect of combined humic acid and inorganic nutrient application significantly improved wheat growth parameters and yield attributes. Among the different residual treatments, T₁₂ (100% RDN + humic acid @30 kg ha⁻¹) showed the maximum plant height (81.9 cm at 90 DAS), highest tiller count (190 m⁻² at harvest), and dry matter accumulation (420 g m⁻² at harvest). Additionally, it recorded the highest grain yield (42.51 q ha⁻¹), straw yield (52.54 q ha⁻¹), and biological yield (95.05 q ha⁻¹). The integrated application of humic acid with 100% recommended nitrogen dose significantly enhanced nutrient uptake and growth, which in turn sustained wheat productivity. Thus, the integrated use of humic acid with recommended doses of inorganic nutrients could be employed to sustain wheat productivity and maintain soil fertility, which often deteriorates under the sole application of chemical fertilizers. This integrated nutrient management approach presents a promising strategy for improving wheat production sustainably under rice-wheat cropping systems in the western plain zone of Uttar Pradesh.