the composition of wheat kernels is independent of the composition of the seed or the nature of the soil, but depends primarily upon the prevailing climatic conditions, including the water supply.  The weight of the wheat per bushel, that is, the average size and weight of the wheat kernel, and also the hardness or flinty character of the kernels, were strongly affected by the varying climatic conditions.  It is generally true that dry-farm grain weighs more per bushel than grain grown under humid conditions; hardness usually accompanies a high protein content and is therefore characteristic of dry-farm wheat.  These notable lessons teach the futility of bringing in new seed from far distant places in the hope that better and larger crops may be secured.  The conditions under which growth occurs determine chiefly the nature of the crop.  It is a common experience in the West that farmers who do not understand this principle send to the Middle West for seed corn, with the result that great crops of stalks and leaves with no ears are obtained.  The only safe rule for the dry-farmer to follow is to use seed which has been grown for many years under dry-farm conditions.

A reason for variation in composition

It is possible to suggest a reason for the high protein content of dry-farm crops.  It is well known that all plants secure most of their nitrogen early in the growing period.  From the nitrogen, protein is formed, and all young plants are, therefore, very rich in protein.  As the plant becomes older, little more protein is added, but more and more carbon is taken from the air to form the fats, starches, sugars, and other non-nitrogenous substances.  Consequently, the proportion or percentage of protein becomes smaller as the plant becomes older.  The impelling purpose of the plant is to produce seed.  Whenever the water supply begins to give out, or the season shortens in any other way, the plant immediately begins to ripen.  Now, the essential effect of dry-farm conditions is to shorten the season; the comparatively young plants, yet rich in protein, begin to produce seed; and at harvest, seed, and leaves, and stalks are rich in the flesh-and blood-forming element of plants.  In more humid countries plants delay the time of seed production and thus enable the plants to store up more carbon and thus reduce the percent of protein.  The short growing season, induced by the shortness of water, is undoubtedly the main reason for the higher protein content and consequently higher nutritive value of all dry-farm crops.

Nutritive value of dry-farm hay, straw, and flour