Answer:
Crop rotation
Step-by-step explanation:
Plant obtain nutrients from the soil. Plantation of crops in soil depletes nutrients from the soil. Crop rotation is one of the methods used for maintaining the nutrient levels and thereby, the productivity of the soil. Crop rotation includes plantation of different crops in the same field. For example, farmers plant legume crops after the non-legume crops. Leguminous plants have Rhizobium bacteria in their root nodules. These bacteria fix nitrogen and restore the lost nitrogen from the soil.