Cover crops are grown primarily for reasons other than short term economic gain. In other words, cover crops are not produced for sale, but rather for the benefits they provide to the production of subsequent cash crops. Cover crops are so-called because they protect otherwise bare soil against erosion. Cover crops are also called “green manure” since they are integrated back into the soil they increase fertility. Cover crops can maintain or increase soil biodiversity, either to compliment crop monocultures, or provide soil nutrients during fallow periods between crops.