Repeated growing of crops in the same soil year after year results in the depletion of the various nutrients in the soil, as a result, soil loses its fertility and requires replenishment by:
1. Keeping land fallow
2. Crop rotation
Keeping the field free for a season to make up for the lost nutrients for a season is called fields (land) fallow. During this period, the soil regenerates its lost nutrients by the action of microorganisms present in the soil. This makes the soil ready for the next crop rotation.
The process in which different types of crops are grown alternatively in the same field or soil is called crop rotation.