Biochar application in peanut fields in China improved photosynthesis and yield. Using 10 tons per hectare of biochar showed the best results, increasing peanut yield by 14.6% and kernel yield by 20.2%. This amount of biochar also enhanced leaf photosynthetic capacity, leading to better plant growth and nitrogen accumulation. Overall, applying biochar at the right amount can be a promising strategy for improving peanut production in the region.