SOIL QUALITY AND NUTRIENT DYNAMICS AS AFFECTED BY RESIDUE MANAGEMENT IN MAIZE–WHEAT CROPPING SYSTEM UNDER REDUCED NITROGEN INPUTS

Abstract

Excessive nitrogen fertilization and poor residue management in wheat–maize systems have resulted in declining soil fertility in Pakistan. This study assessed the effects of different residue management practices and reduced nitrogen rates on soil properties over two consecutive seasons (2021–2023) at the University of Agriculture Peshawar. Results indicated that application of reduced nitrogen rates (90 kg N ha⁻¹ for wheat and 112.5 kg N ha⁻¹ for maize) significantly improved soil electrical conductivity (0.87–0.88 dS m⁻¹), mineral nitrogen (12.3–14.1 mg kg⁻¹), total nitrogen (804–835.9 mg kg⁻¹), organic matter (1.15–1.20%), potassium (105.0 mg kg⁻¹ in wheat; 99.4 mg kg⁻¹ in maize), and soil moisture (15.3–15.4%). Similarly, 100% residue incorporation into the soil enhanced soil mineral nitrogen (14.0 mg kg⁻¹), total nitrogen (802–810.8 mg kg⁻¹), organic matter (1.26–1.36%), phosphorus (3.8–3.9 mg kg⁻¹), potassium (103.5–104.9 mg kg⁻¹), and soil moisture (15.9–16.2%) compared with control plots. These results demonstrated that integrating full residue incorporation with optimal nitrogen rates greatly improves soil nutrient status and moisture conservation, thereby sustaining soil fertility in the wheat–maize cropping system