The growing of different crops on a piece of land in a pre planned succession is called crop rotation.
Most pathogens do not infect multiple crops and survive on plant residue. Therefore, by rotating winter and summer crops, the farmer fights summer weeds in winter and vice versa.
Land left fallow or bare may be susceptible to leaching and erosion. Crop rotation prevents this. Several crops may be grown in succession with only one time ploughing of the soil. For example, maize stubble containing nutrients is left on the land for wheat. Crop rotation involving leguminous plants ensures a regular supply of nitrogen in the soil.
Risks are distributed among several crops as a guarantee against crop failure.
