Wheat is raised under these conditions in central and western Kansas, Nebraska, most of the Dakotas, eastern Washington, Oregon and Califor nia, and in Manitoba, Alberta and Saskatchewan. Experiments indicate that the use of commercial fertilizers for wheat or other cereal crop is not of immediate profit in this region, and as barnyard manure dries out the soil the problem of maintain ing fertility is a serious one. Doubtless it is to be accomplished by seeding to perennial grasses or legumes for a period of years. In the eastern states, where the rainfall is ample and where the soluble plant-food materials are continually leached from the soil, commercial fertilizers are used with profit, either on the wheat crop direct or on a preceding crop. Throughout much of this region wheat is grown because it is useful in filling out a rotation or in providing a nurse crop for grass and clover rather than because it is profitable in itself.
If wheat follows corn the land should receive ten to thirty loads of barnyard manure before plowing for the latter crop. This is much better than applying manure directly to wheat, which, however, will generally be benefited by an appli cation of commercial fertilizer. The nature and amount of such fertilizer will depend largely on the character of the soil. The only accurate method of ascertaining the manurial requirements for any particular soil is to conduct a test on the soil in question.
A complete fertilizer, that is, one containing nitrogen, phosphoric acid and potash, is generally preferable to one containing only one or two of these substances. On a light, well-drained soil, relatively more phosphoric acid is needed, while on a heavy moist soil more nitrogen, preferably in the form of nitrate, should be used. Two to four hundred pounds of what is known to the trade as a 4-12-4 fertilizer is frequently used. The form in which the phosphoric acid is combined does not make much difference if the material is very finely ground.
Place in the rotation. (T. L. Lyon.) Wheat should always be grown in a rotation with other crops. It is particularly benefited by such treatment and suffers in productiveness very rapidly when grown continuously on the same soil. Wheat yields begin to decrease on the prairie soils within a few years after they are broken, while corn will continue to yield without diminution for ten, twenty or even thirty years on some of the rich prairie soils.
The rotations in which wheat is grown vary in different parts of the country. In the New England and north Atlantic states, where corn is raised largely for silage, a system consisting of corn, wheat, clover is frequently followed. This is well
suited to dairy-farming. Where oats are needed, they usually follow directly after corn and precede wheat, making the rotation corn, oats, wheat, clo ver. Potatoes are frequently substituted for corn.
In the corn-belt states, when wheat is raised the rotation is usually corn two years, oats, wheat, clo ver, except where spring wheat is grown, when it is often used to alternate with corn; thus,—corn, spring wheat, using no other crop in the rotation. This is not an ideal system, but experience has shown that it is better than raising corn continu ously. This method is also being followed at present with winter wheat by drilling the wheat between the corn rows with a one-horse drill. The corn stalks are pastured in winter, so that the wheat can be harvested the following summer.
In the semi-arid region the tendency is to rotate wheat with a summer-fallow, using the latter every two to four years. It is probable that this will be replaced in time by a rotation including a peren nial grass or legume left on the land for several years, and alternating wheat with other small grains suited to the region as well as the summer fallow.
On the irrigated lands, sugar-beets or potatoes are usually the cultivated crops. These follow alfalfa, which has been down for at least three or four years. Wheat follows the cultivated crop. A typical rotation is alfalfa (three or more years), sugar-beets, wheat. Where peas are raised for sheep, as is becoming common in Colorado, a good rotation is peas, potatoes, wheat.
Seed and seeding.
The great importance of securing good seed is evident. While efforts should not be neglected to improve the character of well-known varieties and to create new ones of superior merit, it must not be forgotten that the maximum of production from the varieties now in common use has by no means been reached. Much remains to be learned of the adaptability of existing wheats and the best methods of cultivating and handling the crop.
The wheat-grower cannot be too painstaking in the selection of his seed wheat. By employing the methods previously mentioned of cleaning and grading the seed, improvement is sure to follow. Shriveled wheat will germinate, but the best results cannot be expected from such seed. In many regions it is absolutely necessary to treat the seed with some chemical to destroy the germs of smut. [See below under Enemies.] Seeding.—The time for sowing will depend on the climatic variations and on the dangers of attack from the Hessian fly.