Adding composted biochar to soil can help plants grow better and improve soil fertility. The researchers tested different amounts and mixtures of biochar and compost to see how they affected oat plants and soil properties. They found that increasing biochar and compost amounts led to more plant biomass. Biochar alone improved plant height and seed weight, likely due to increased organic carbon and nitrogen in the soil. Composted biochar can enhance plant growth and soil quality, making it a useful tool for improving nutrient cycles on farms.