Covering the soil with plant cover
One of the main concepts of regeneration agriculture is not to leave the soil bare. To do this, we sow vegetation cover between two crops. These covers (or intermediate crops) are plants that maintain soil moisture, restructure the soil with their roots and enrich it with carbon and nitrogen. Legumes are often used (the bean family: cowpea, clover, etc.).
Working with a permanent vegetation cover is an opportunity to place species favorable to the plants we cultivate. In this way, the plants help each other without competing (see "associated crops").
These plant covers are then used as "green manures".
In regenerative agriculture, organic fertilizers are always preferred to synthetic mineral fertilizers. However important the quantity of fertilizer, it is not sufficient to restore a compact soil without biodiversity. They will even make the situation worse.
In addition to increasing the nitrogen content for the nutrition of other plants (corn...), plant cover directly feeds the soil fauna. If the soil is left bare, the microorganisms can no longer feed and may die. Thus, the straws of crop residues feed the soil life and increase the general biodiversity.
Legumes can serve as a nitrogen fertilizer by converting nitrogen from the air into a form that can be used by plants. The deep root system of tropical legumes can form a nutrient-rich plant mulch. In the long term, this mulch increases soil fertility. This deep root system also benefits cereals because it can make nutrients penetrate more deeply. A final advantage is that legumes are often suitable for human or animal consumption.
The main advantages of plant cover crops and their return to the soil are :
Preserve soil moisture
Increase the carbon and nitrogen content of the soil
Nourish soil life
Improve soil structure
Diversify food production