Green manuring is the practice of growing green plants or adding plant materials and incorporating them into the soil to improve soil structure and fertility. There are two main types - green leaf manuring, which involves collecting and adding leaves and twigs from elsewhere, and green manuring in situ, which involves growing plants like legumes and incorporating them into the soil before or at flowering. Green manuring benefits the soil by increasing nitrogen levels, improving soil structure and water retention, reducing erosion, and reclaiming saline or alkaline soils. Common green manure crops include sunn hemp, dhaincha, sesbania, and clusterbeans.