How Wheat Is Raised
Wheat has a wide range of cultivation because of its many varieties. Some kinds of wheat are grown at elevations of 12,000 feet (3,700 m), others below sea level. Wheat is grown in the tropics and within the Arctic Circle. However, the most valuable wheat can be grown successfully only in the temperate regions where the annual rainfall is less than 30 inches (760 mm). The soils best suited for the growing of wheat are loamy and rich.
Wheat farmers usually practice crop rotation, to keep form exhausting the soil and to control the weeds, plant diseases, and insect pests. In some areas, wheat land is allowed to remain idle, or fallow, a year or two to conserve moisture and minerals.
In the larger wheat-producing countries, wheat farming is highly mechanized. In developing countries, however, the work is generally still done by hand, or with the help of simple machines.
After the ground is prepared by plowing and certain other methods, machines plant the seeds (kernels) either by sowing them broadcast (that is, distributing them on the surface of the ground) or by drilling furrows and planting the seeds in rows. Spring wheats are planted as early as the soil can be worked; winter wheats are planted in early fall. The leaves of spring wheat appear above ground about two weeks after planting. Winter wheat sprouts, stops growing with the first freeze, then resumes its growth in the spring.
Wheat requires little cultivation except weed control. Weeds are killed by plowing between the rows of drill-planted wheat, or by spraying with chemicals.
To prevent scattering of the kernels, wheat is usually harvested before it is fully ripe. There are several steps in harvesting: cutting, or reaping, the stalks; threshing and winnowing, to separate the kernels from the spikes, glumes, and other chaff; sifting and sorting the grain; loading the grain into trucks; and binding the straw. On large farms, huge machines called combines, manned by small crews, perform all of the harvesting processes. .)
Wheat must be stored in dry, well-ventilated buildings that keep out insect pests. Wheat is stored for a short time in bins or granaries on the farms. It is then hauled to country elevators, tall structures where the grain is dried and stored until it is sold locally or shipped to terminal elevators. Terminal elevators are immense buildings, each holding 1,000,000 bushels (27,000 metric tons) or more. They are grouped at large inland distributing centers and at seaports, where the wheat may be stored almost indefinitely. .)