Why are leguminous plants often used in crop rotation
Leguminous plants take up less nutrients
Leguminous plants keep away the pests
Leguminous plants fix nitrogen
The correct option is A Leguminous plants fix nitrogen
Legumes have bacteria on nodules which are on the roots of the plant. The bacteria on the nodules take nitrogen from the air and fixes it into the soil so that other plants(when there is crop rotation) that require nitrogen can use it as well.