Growing different crops in the same place during successive seasons.
crop-rotation is the process of planting different crops in the same location during successive seasons. Typically the same crops are used in a three or four year cycle - ie. a rotation through each growing area.
Crop rotation can be used to maintain soil fertility with the use of a legume or green manure in crop sequence to replenish nitrogen levels.
By alternating deep and shallow routed crops, crop rotation also improve the soil's structure and humus content.
Crop rotation can also be effective in helping to control pests and pathogens, by choosing greatly different crops in successive years. A pest or pathogen may attack one one year and be retained in the soil, but it cannot effectively attack the next year's crop because it is a different type of crop. Therefore the infection rate of the pest or pathogen does not rise, but instead it will usually drop.
There are a number of different crop rotation systems depending on the climate and desired crops. A major component of the Agricultural Revolution in Western Europe (circa 1700s) was the move from a Three Course Rotation (two crops, one fallow) to the Norfolk Four Course Rotation (three crops, one legume).
Use this tag for all questions about crop rotation in a horticultural setting.