Farmers often practice crop rotation to help enrich agricultural fields. Why are beans and other legumes often used in the rotations?
A. Beans fix nitrogen.
B. Legumes enrich the soil by forming heterocysts.
C. Bacteria in legume root nodules are nitrifiers.
D. Legumes remove toxins from the soil.
E. Less carbon dioxide.
Answer:
C. Bacteria in legume root nodules are nitrifiers.
Step-by-step explanation:
Beans and other legumes have bacteria in their root nodules. These bacteria are symbiotic bacteria. They benefit the host plant by converting the molecular nitrogen present in the soil into the ammonia. This process of nitrogen fixation makes the nitrogen available to the plants. Therefore, rotation of the crops with leguminous crop improve the soil fertility by adding the biologically usable form of nitrogen into the soil which in turn can be used by non-leguminous crops.