The Winter Wheat and Grazing Region

J. A. Hobbs.

The winter wheat and grazing region of the Great Plains includes the subhumid and eastern semiarid sections of the central and southern Great Plains. The rainfall is irregular. The soils mostly are fertile. Winter wheat is the main crop. Considerable land remains in native grass, which is grazed.

The average annual precipitation is more than 38 inches in the southeast and less than 14 inches along the western edge. That is enough moisture for satisfactory growth of adapted crops if one uses recommended practices.

Precipitation has been as low as 50 percent of average and higher than 200 percent of average in almost all parts of the region. Generally the number of years with below-average rainfall slightly exceeds the number with above-average precipitation. Seasonal as well as annual irregularities are common.

Considerable variation in temperature also occurs. The average growing season the period without a killing frost is closely related to the mean temperature for the different sections. The average growing season ranges from more than 210 days in the southeastern part to fewer than 140 days in the northwestern section.

The wide variations in climate would lead us to expect a wide variation in native vegetation. The variation does occur, but the native vegetation over the whole region is grass. Some small favored sites support trees. Bluestems, both big and little, and associated tall and mid grasses grow in the eastern parts. Farther west where it is drier, short grasses come into the native sward, until in the western section the short grasses, such as buffalograss and the gramagrasses, are the most common species on the uplands. Taller grasses tend to dominate on the sandier soils and on bottom lands.

A diversity of soils developed under this climate and native vegetation. The soils include the deep, dark Prairie and Reddish Prairie soils of the eastern sections; Chernozem soils in the central parts; and the shallower and lighter colored Chestnut, Reddish Chestnut, and Brown soils of the west.

Scattered through these zonal soils are some shallow soils on bedrock and some sandy soils and sand dunes. These soils and the fine-textured, tight, impermeable soils pose problems of management, but the areas are too small to designate and discuss here. The narrow belts of highly productive, alluvial soils along the many stream channels also are too small to delineate.

This winter wheat and grazing region can be divided into four subregions: The Flint Hills subregion, the Dakota Sandstone subregion, the subhumid wheat subregion, and the summer fallow subregion.

THE FLINT HILLS subregion is a rough, dissected section of shallow soils on shale and limestone bedrock. Mostly it is uncultivated and is used primarily for summer grazing. The bluestems and the associated grasses still prevail, and they and the climate and fertile soils have given to the Flint Hills a reputation of being one of the most productive native grass pasture areas in the United States.

Some breeding herds are maintained, but much of the land is leased to western or Texas cattlemen at a cash rent per animal for the season. The cattle are shipped in to pasture in April and May and are shipped east to market when they are in finished condition or when the pasture is no longer useful.

Areas of soils suited to cultivation are scattered over the relatively level ridgetops. They tend to be fine textured and have tight, impermeable subsoils. Colluvial and alluvial soils at the base of slopes and on the small bottom land areas also may be tillable. These level upland soils and the colluvial and alluvial soils are limited in extent, but they are highly important to farmers winter feed and forage for stock come from them.

Good management of the soils of the Flint Hills is nearly synonymous with good management of pastures.

Management of grazing on range pastures usually involves the maximum utilization of grass, with efficient livestock production and maintenance of the range. The large numbers of transient cattle in the Flint Hills have meant that emphasis has been put on rapid gains during the early part of the pasturing season. That places a premium on the "early bite." To gain that end, annual burning of pastures has been practiced since the early 1880's, and the practice has been written into many leases.

That the range has been maintained under such conditions is due mainly to other features of the leasing agreements. Cattlemen have demanded adequate acreage allowances per animal to promote good gains. That and the fact that many animals attain market finish in midsummer permit the grasses to make a good growth in late summer.

Necessary reserves of carbohydrate thus are replenished in the grass roots and crowns.

Some deterioration has been noted, especially in pastures grazed the full season without reduction in stocking load and in smaller pastures, which almost always are overstocked.

The adjustment of acreage allowance to the productive capacity of the grass is highly important. Not all cattlemen realize that when range is "fully utilized" about half of the current year's growth should remain at the end of the pasture season.

Additional practices needed in these pasture areas include a reduction or Complete prevention of burning and the provision of adequate and properly spaced watering and salting sites. Because wells are often inadequate in the long, dry seasons, ponds and other structures should be made to supplement the water supply. Places that have started to gully because of overgrazing should be fenced off and allowed to recover.

Danger of erosion is great on the sloping cultivated fields on the uplands. Many of the cultivated lands are underlain by slowly permeable subsoil. Runoff and the likelihood of soil loss are greater on them. These lands should be cultivated on the contour. Terraces should be used when they are needed to control erosion. Applications of fertilizer will increase production of crops. The denser stands and heavier residues resulting from fertilization help reduce erosion losses. Little benefit from deep chiseling has been seen in carefully controlled experiments.

THE DAKOTA SANDSTONE SUBREGION, another grazing area, is just west of the Flint Hills. Its soils are strongly acid and very low in available phosphorus. Originally the grass cover was like that of the Flint Hills. Because of the lower annual rainfall and poorer soils, this section succumbed more quickly to overgrazing. Now it is much more depleted, and it does not have the reputation as a grazing area that the Flint Hills region has.

The cattle usually are raised locally and retained until they are shipped to the market.

Steep slopes and overgrazing have permitted some water erosion. The cultivated soils are highly erosive. Frequently they are shallow over bedrock and are infertile. Wind erosion has been serious when dry weather or low fertility has reduced the vegetative cover to any sizable extent.