Green manure refers to crops that are grown specifically to be turned back into the soil to improve its fertility. These plants, often legumes or cover crops, are cultivated for a short period and then plowed under before they mature. This process enriches the soil with organic matter and nutrients, enhancing its structure and health. Using green manure can help prevent soil erosion, suppress weeds, and promote beneficial microorganisms. Common examples include clover, vetch, and rye. Farmers and gardeners often incorporate green manure into their crop rotation practices to maintain sustainable agricultural systems.