Crop rotation on arable land is the practice of alternating crops grown on a specific field in a planned pattern or sequence in successive crop years so that crops of the same species are not grown without interruption on the same field. In a rotation the crops are normally changed annually, but they can also be multi-annual. If the same crop is grown continuously, the term monoculture can be used to describe the phenomenon.
Although there is no limit to the number of crops that are used in a rotation, nor in the amount of time that a rotation takes to complete, it is commonly accepted to use a threshold of 5 years to separate arable land from permanent crops or permanent grassland. This means that if a plot is used for the same crop for 5 years or more, without in the meantime removing the preceding crop and establishing a new one, then this plot is not considered to be in crop rotation and therefore is not to be taken as part of arable land.
There are crops that do not fit this pattern, and that are treated differently. For example hops has been chosen to always be an arable crop, despite being perennial and often being renewed at intervals beyond 5 years, and berries are considered permanent crops despite being renewed sometimes annually.
- Land under temporary agricultural crops, with multi-cropped areas counted only once
- Land that has been left fallow for less than 5 years
- Certain crops which are usually treated as vegetables, as ornamental plants or as industrial plants, such as asparagus, roses, decorative shrubs cultivated for their blossom or leaves, strawberries or hops even if they might occupy the land for more than 5 years
- Areas with energy crops (for the production of biofuels or other renewable energy) that can be occupying the arable land for much more than 5 years such as Miscanthus spp.
- Arable land under glass or high accessible cover (ARAS)
- Berries plantations even if their permanence on the plot is less than 5 years (PECR)
- Land that has been definitely taken out of cultivation even if less than 5 years have passed since it was last cropped
- Cultivated mushrooms (U1000)
- Farm structure (ESMS metadata file — ef_esms)
- Survey on agricultural production methods (background article on the organisation and list of characteristics surveyed)
- Agri-environmental indicator (AEI)
- Farm structure survey (FSS)
- Survey on agricultural production methods (SAPM)