Agroforestry‐Based Soil Health: Impact of Tillage and Mulching on Soil Properties, Microbial Communities, and Microbial Necromass in Calcareous Soils

ABSTRACT Agroforestry‐based soil management practices offer a promising solution for enhancing soil health and carbon sequestration, particularly in vulnerable calcareous soil. This study evaluated the impact of integrated tillage and mulching strategies on soil microbial activity, carbon storage, and nutrient cycling in the semi‐arid calcareous soils of the Sulaiman Range, Pakistan. The field experiment was initiated at wheat sowing in November 2022, and soil sampling for the present analysis was conducted after two consecutive wheat‐growing seasons (April 2024), enabling the assessment of medium‐term treatment effects. A field experiment was conducted using a randomized complete block design with five treatments: conventional tillage without mulch (CT), reduced tillage with organic mulch (RT), no‐tillage with cover crop mulch (NTC), strip tillage with plastic mulch (STP), and no‐tillage with biochar mulch (NTB). Results revealed that NTB significantly improved soil health indicators, with 76.2% and 98.2% increases in soil organic carbon and total nitrogen, respectively, compared to CT. Microbial biomass carbon, nitrogen, and phosphorus were also highest under NTB, aligning with elevated enzyme activities (β‐glucosidase, N‐acetylglucosaminidase, and phosphatase) and enhanced microbial carbon use efficiency. Microbial necromass carbon, estimated via amino sugar biomarkers, contributed substantially to soil organic carbon under NTB, highlighting the role of microbial residues in soil carbon stabilization. Additionally, vector and stoichiometric analyses of enzyme activities indicated that NTB alleviated phosphorus and nitrogen limitations for microbial communities. These findings demonstrate that no‐tillage combined with biochar mulch fosters microbial‐mediated carbon accumulation and nutrient retention in calcareous soils, offering a viable strategy for climate‐resilient agroforestry systems in the Sulaiman Range and similar semi‐arid regions.