Biochar application enhances stress resistance and promotes crop growth by improving soil properties. This review summarizes the effects of biochar on soil and crops under various stresses, including drought, salinity, and heavy metals. Biochar, a carbon-rich material derived from biomass pyrolysis, has physicochemical properties such as a porous structure, alkaline nature, and nutrient content that improve soil physiochemical properties, nutrient cycling, and microbial growth. It enhances soil structure, increases water-holding capacity, and reduces bulk density, thereby improving root development and nutrient uptake. Biochar also mitigates heavy metal and pesticide pollution by adsorption or microbial degradation, and increases soil cation exchange capacity, which helps in nutrient retention and pH adjustment. The review highlights the role of biochar in enhancing crop resilience under stress by promoting root growth, nutrient cycling, and microbial activity. It also discusses challenges in the sustainable and economical use of biochar in extreme soil conditions. Overall, biochar application can improve soil health, crop productivity, and food security.Biochar application enhances stress resistance and promotes crop growth by improving soil properties. This review summarizes the effects of biochar on soil and crops under various stresses, including drought, salinity, and heavy metals. Biochar, a carbon-rich material derived from biomass pyrolysis, has physicochemical properties such as a porous structure, alkaline nature, and nutrient content that improve soil physiochemical properties, nutrient cycling, and microbial growth. It enhances soil structure, increases water-holding capacity, and reduces bulk density, thereby improving root development and nutrient uptake. Biochar also mitigates heavy metal and pesticide pollution by adsorption or microbial degradation, and increases soil cation exchange capacity, which helps in nutrient retention and pH adjustment. The review highlights the role of biochar in enhancing crop resilience under stress by promoting root growth, nutrient cycling, and microbial activity. It also discusses challenges in the sustainable and economical use of biochar in extreme soil conditions. Overall, biochar application can improve soil health, crop productivity, and food security.