HOW TO GRAZE BLUE GRAMA ON SOUTH- 

 WESTERN RANGES 



By Edward C. Crafts, associate forest ecologist, and George E. Glendening, 

 assistant forest ecologist, Southwestern Forest and Range Experiment Station, 

 Forest Service 



On 48 million acres in Arizona and New Mexico, or more than a 

 third of the total usable range in these States, as well as on ranges in 

 adjacent Texas, blue grama is the dominant forage plant. Through- 

 out this region, which is here loosely termed the Southwest, blue 

 grama is of primary importance on 13 national forests, on other public 

 lands, and on great areas of private range. 



There are three outstanding reasons for this superiority. Blue 

 grama provides excellent forage, is highly resistant to grazing and 

 drought, and is an effective soil binder. To a considerable degree the 

 welfare of the livestock industry in the Southwest is dependent upon 

 maintaining the dominance of blue grama and the further protection 

 and extension of present well-established stands. For these reasons 

 a widespread understanding of the simple principles of utilization and 

 management required to maintain this high-grade forage and to make 

 the most of its soil-protective characteristics is highly desirable. 



What Blue Grama Is and How it Grows 



Blue grama, like all other true gramas, is characterized by flaglike 

 seed heads extending out from the stalk. (See cover.) The different 

 species of grama can be identified by the number, size, and shape of 

 these "flags." For example, blue and hairy gramas have from one to 

 three, but usually two, per flower stalk. These two gramas, often 

 found growing side by side, can be distinguished by the characteristics 

 of the "blackbone" of the seed head. In hairy grama it extends 

 noticeably beyond the seed head, whereas in blue grama there is no 

 conspicuous prolonged point. When not in flower, blue and hairy 

 gramas are not so easily distinguished; familiarity with the relative 

 degree of hairiness of the leaves of the two species is essential — a detail 

 that can be readily mastered through careful observation. 



Black grama, another associated species, can be differentiated by its 

 more slender seed heads and the greater number of them (two to eight, 

 usually four to five) and by its runners and stolons, which are lacking 

 in blue grama. 



Blue grama is found from Wisconsin to California and from Alberta 

 to Mexico. In the Southwest it occurs on dry plains, foothills, and 

 plateaus. Its greatest abundance is in the short-grass region of western 

 Texas and eastern New Mexico and in the pinon-juniper woodlands 

 of Arizona and New Mexico, but it also extends upward into the 

 ponderosa-pine zone and downward into the upper edge of the semi- 

 desert grasslands. It is found at elevations of 3,500 feet on the 

 2 



436128°— 42 



