Dry farming, type of agriculture without irrigation used in areas where less than 20 in (50 cm) rainfall per year prevents the use of traditional methods of farming. After harvest the land is tilled and kept free of weeds to reduce loss of moisture. Where crops are sown in spring, stubble of the previous year's crop is often allowed to stand over winter to trap snow. In very dry areas ground is left fallow in alternate years, allowing it to store up moisture. Fields are contoured and clods of dead vegetable matter are kept in the fields to prevent water runoff and make possible more efficient use of rainfall. Dry farming is frequently practiced in the U.S. and Canadian West, the Great Plains, the Mediterranean basin, the former Soviet Union, and interior areas of Australia and Asia. Among the crops appropriate for dry farming are corn, sorghum, and wheat. Crops grown this way are usually small in size and are quicker to mature than those grown in more moist areas.
See also: Agriculture.