Q. Why is a leguminous crop rotation used in agriculture?
The Leguminous crop rotation and other crop rotations are used in agriculture for the reason that in these plants many bacteria vital for the nitrogen cycle live. The leguminous crop rotation (or cojointly with the main crop) helps the soil to turn into rich in nitrates that are then absorbed by the plants.
The Green manure, the covering of the soil with leguminous plants and grass, is also a way to improve the fixation of nitrogen and it is an option in avoiding chemical fertilizers.