Comparative ranges of adaptation of species of cultivated grasses and legumes in Oklahoma

The difficulties encountered in the selection of perennial forage plants in the southern Great Plains area are pointed out. The distribution of groups of forage crops in relation to the types of native vegetation of Oklahoma is given, together with a discussion of the factors favoring and limiting the distribution of the several groups. The yields, ranges of adaptation, factors favoring, and factors limiting the growth and employment of 18 species of cultivated grasses and 14 species of legumes are discussed. Many of the northern grasses, such as timothy, creeping bent, Kentucky and Canada bluegrasses, smooth brome, and slender wheat, showed themselves to be poorly adapted to the high temperatures and the at times dry periods of the summers of central Oklahoma. Such typical sod-forming grasses as creeping bent, Kentucky bluegrass, and smooth brome developed typical bunch habits of growth under prevailing conditions. This was taken as an index of lack of vigor and aggressiveness. Meadow fescue, while more drought resistant and better able to endure high temperatures than the above-mentioned northern grasses, was not sufficiently vigorous to be of great value. The fine-leaved fescues, such as sheep, hard, and red fescue, while low yielders, have shown themselves to be very drought resistant or rather drought escaping due to their ability to grow early in the season. The rye grasses, while producing high yields during the first vegetative season, especially following fall seedings, were short lived, behaving in practically all instances as annuals due to their inability to endure high summer temperatures. Tall oat, orchard grass, and redtop showed themselves to be constant yielders with a high degree of drought and high temperature endurance and sufficiently aggressive to be of value on the better soils of east-central and eastern Oklahoma. They are not sufficiently drought resistant, however, for employment on thin, dry upland soils in the central part of the state. On the better, fairly well watered soils these grasses may well be grown in combination with sweet clover in the central and with alsike and red clover in the eastern part of the state. Of the true southern grasses, bermuda alone proved sufficiently hardy to endure winter conditions in north-central Oklahoma. Carpet grass was not as drought resistant as bermuda. Dallis grass showed a most remarkable degree of drought resistance but was not winterhardy. Alfalfa and sweet clover have shown themselves to be the most dependable legumes for central Oklahoma. None of the true clovers are in position to compete with these two crops in the central part of the state. As the more humid eastern part, especially the northeastern portion of the state, is approached a definite place is found for the true clovers. The true clovers can be grown in north-central Oklahoma only with special care and on well-watered soils. Black medic and subterranean clover did not prove sufficiently drought resistant for Oklahoma conditions. Bur clover was not sufficiently winterhardy for north-central Oklahoma, but it has a place in the eastern and southeastern portions of the state. Crimson clover survived the winter of 1926-27 but did not yield enough to be of practical value. The lespedezas lack in drought resistance to be of practical value in the central part of Oklahoma, except in special locations and for special purposes. They have a definite place in the more humid portions of the state. Both Korean and Kobe have shown themselves to be superior to Japanese lespedeza.