Editing Crop rotation (section)

=== Pathogen and pest control ===

{{Main |Plant–soil feedback}}

Crop rotation is also used to control pests and diseases that can become established in the soil over time. The changing of crops in a sequence decreases the population level of pests by (1) interrupting pest life cycles and (2) interrupting pest habitat.<ref name="johnson2009"/> Plants within the same [[taxonomic family]] tend to have similar pests and pathogens. By regularly changing crops and keeping the soil occupied by cover crops instead of lying fallow, pest cycles can be broken or limited, especially cycles that benefit from overwintering in residue.<ref name=moncada2010/> For example, [[root-knot nematode]] is a serious problem for some plants in warm climates and sandy soils, where it slowly builds up to high levels in the soil, and can severely damage plant productivity by cutting off circulation from the plant roots. Growing a crop that is not a host for root-knot nematode for one season greatly reduces the level of the nematode in the soil, thus making it possible to grow a susceptible crop the following season without needing soil [[fumigation]].

This principle is of particular use in [[organic farming]], where [[biological pest control|pest control]] must be achieved without synthetic pesticides.<ref name="NCATweb"/>