Crops are plants grown in quantities harvested for food or fodder for livestock. Cash crops are those that are grown for sale as food. Today most large quantities of crops grown on farms are destined for markets within the same country and are often exported to other countries.
The types of crops grown in an area depend on the climate and the fertility of the soil. In tropical areas common cash crops include jute, coffee, cocoa, oranges, bananas, cotton, and papaya. In colder areas, grain is the main crop as well as vegetables, such as potato, turnip, carrot and cabbage. When crops grow in abundance in one area and are hard to get in other areas, they become cash crops because the farmers have a ready market in the customers wanting to purchase them.
Subsistence crops are those grown by homeowners in small gardens. The crops are mainly vegetables and herbs for their own use. Some of these farmers may set up roadside stalls to sell the excess crops that will only spoil if they keep them too long.
Potatoes and other root crops are the most widely grown of all crop types. Planting and harvesting is labor-intensive and requires the use of specialized machinery. White straw crops include wheat, barley and oats. These are exhaustive crops that require farmers to have several fields that they rotate for use in successive years. They also encourage the growth of grass weeds.
Some other cash drops are called break crops. These include oilseed-rape, peas, linseed and beans. They are often planted between fields of potatoes and other crops to provide a break between them, hence the name. Oilseed-rape acts as a cleaning crop as well because it serves to break down the grass weeds that build up. Peas and beans return nutrients to the soil. In this way, they are also restorative crops like kale, which also returns nutrients to the soil.
Farmers vary the crops they plant next to each other because planting the same crops in the same fields year after year adds to diseases of the soil.