BIOCHAR APPLICATION IMPACT ON SOIL ORGANIC CARBON AND NUTRIENT AVAILABILITY IN WHEAT UNDER GREENHOUSE CONDITIONS

Biochar amendment has emerged as one of the most promising multi-functional soil management strategies for simultaneously improving soil organic carbon (SOC) sequestration, nutrient availability, and crop productivity in the degraded agricultural soils of Pakistan.The progressive depletion of soil organic matter in intensively cropped lands of Punjab threatens long-term soil health and food security.This greenhouse study, evaluated the impact of four rates of rice-husk biochar (1%, 2%, 3%, and 4% w/w) compared to an unamended control on fifteen soil physico-chemical and wheat (Triticum aestivum L.) yield parameters under a completely randomized design (CRD) with four replications.Soil organic carbon increased progressively from 0.42% in the control to 1.38% at the 4% biochar rate, while available phosphorus improved from 6.2 to 18.6 mg kg-1 and available potassium from 112 to 218 mg kg-1 at the 3% biochar rate.Soil pH declined marginally from 7.82 to 7.24, and cation exchange capacity (CEC) increased from 12.4 to 19.8 cmolc kg-1 at the highest biochar rate, reflecting enhanced surface charge and nutrient retention.Hydraulic conductivity, bulk density, and aggregate stability all showed significant (p