It can play a major role in pest control because many pests have preferences for specific crops. Growing different crops interrupts pest life cycles and keeps their populations in check. For example, right now European corn borers are often a significant pest because most corn in the United States is grown in continuous cultivation or in two-year rotations with soybeans. Such rotations would control not only corn borers, but many other corn pests as well. In fact, rotation reduces pest pressure on all the crops in the rotation by breaking the pest reproductive cycles.
Rotation is a key element of the permanent and effective solution to pest problems.
In rotations, farmers can also plant crops, like legumes, that replenish plant nutrients, thereby reducing the need for chemical fertilizers. A good example is soybeans, a valuable crop that also converts nitrogen into a biologically useful form. Corn grown in a field previously used to grow soybeans needs less added nitrogen to produce high yields. Cover Crops An alternative to leaving the ground bare between cropping periods is the planting of cover crops, like hairy vetch, clover, or oats. Although such crops are usually not harvested for sale, they provide multiple benefits by preventing soil erosion, suppressing weeds, and enhancing soil quality.