Phân Xanh và Cây trồng Bao phủ

Green manure crops are crops that are grown to be turned under to increase soil fertility. Leguminous green manure crops ( i.e., those which can make nitrogen fertilizers from atmospheric nitrogen) can offer small-scale farmers a tremendous number of advantages.

In general GMCCs:

• provide large quantities of nitrogen for the soil.
• add many tons of organic matter to the soil, thereby improving topsoil depth, water-holding capacity, nutrient content, friability, and texture of the soil.
• present no transportation problems, in contrast to compost and chemical fertilizers.
• require no capital outlay after the initial purchase of a handful of seed. Because they require no chemical inputs, dependency on outside sources of fertilizer, nutrients, and pesticides is reduced.
• can shade the soil up to eleven months out of the year, a factor extremely important in tropical climates for preservation of soil moisture and organic matter.
• cover they provide for the soil protects it from wind and water erosion.
• provide generous amounts of high protein fodder for animals, which can be especially valuable if it is available during the last months of the dry season.
• sometimes provide human food, including various kinds of edible beans, peas, and pods.
• can provide income, by selling firewood, food or feed.
• often provide an incentive for people to abandon harmful traditional practices, such as burning crop residues or letting animals loose in the dry season to devour everything in sight.
• when intercropped with basic grains, can control weeds, thereby eliminating costly weeding operations