Definition: Green manure refers to crops or plants specifically grown to be chopped or pruned and left on top of the soil to decompose. This added organic matter protects the soil and improves soil fertility, structure, and growing conditions as it decomposes.
Green Manure in the Forest Garden:
There are many types of green manure crops that can be incorporated into the Forest Garden. When thinking about green manure, legumes tend to be the first type of crop that comes to mind as they are known for their ability to fix nitrogen into the soil. Green manure crops are most often used in alley cropping systems, ensuring nitrogen fixation across the field. Planting green manure crops also limits labor needs and the costs of fertilizers.
Cover cropping also allows for green manure incorporation. Farmers can select a cover crop that will not only protect the soil during the dry season, but also provide an abundance of green fertilizer for the following crop as the leaves can be ‘chopped and dropped,’ leaving them to decompose in the soil.