Soil acidity with high levels of aluminum and manganese can limit food production. Lime can help, but it's not always available or affordable. This study tested different organic materials to see if they could improve acidic soils. They found that organic amendments like manures, composts, and biochars were as effective as lime in increasing plant growth. The best performers were poultry litter, poultry-litter-biochar, and biosolids. These amendments also raised soil pH and phosphorus levels, while reducing toxic aluminum and manganese. Overall, organic amendments can help improve soil acidity by providing nutrients and reducing toxic elements.