HOW TO GRAZE BLUE GRAMA ON SOUTHWESTERN RANGES 3 



southwestern plains, at 8,500 feel in the San Francisco Mountains of 



northern Arizona, and even at 10,000 feet on the Carson National 

 Forest in New Mexico. It will endure temperatures ranging from 

 — 40° to 4-110° F. In its region of best growth it is found mainly on 

 loamy soils or the so-called tight lands, but it is also found elsewhere 

 on coarse-textured soils. 



At the higher elevations, where temperatures and evaporation are 

 relatively low and precipitation is relatively high, blue grama tend- 

 to spread out into a dense, ground-hugging turf with short leaves and 

 flower stalks. At lower elevations, however, where temperatures 

 and evaporation are relatively high and precipitation is relatively low, 

 notably on the Coronado National Forest along the Mexican border 

 in southern Arizona, the stand is usually more open, and the plant 

 has more the appearance of a bunchgrass. It is here, at elevations 

 of about 5,000 feet, that blue grama ordinarily makes its best volume 

 growth. 



Blue grama sometimes occurs in almost pure stands, but in the 

 short-grass region is commonly associated with buffalograss. galleta. 

 side-oats, and black and hairy gramas. As this type of range de- 

 teriorates, it is replaced by broom snakeweed, the less palatable 

 three-awns, and ring muhly. In the pinon-juniper woodlands the 

 stand may be nearly pure, but more commonly it includes grasses like 

 bluestem wheatgrass, galleta, and wolf tail. An indication of de- 

 terioration in woodland ranges is the intrusion of broom snakeweed, 

 rabbitbrush, three-awns, ring muhly, and pingiie actinea. Where 

 blue grama occurs within the semidesert grasslands, curly mesquite, 

 and black, hairy, and slender gramas are often found with it. At the 

 higher limits of its distribution, blue grama is a secondary species in 

 stands of mountain muhly. Arizona fescue, pine dropseed, bottlebrush 

 squirreltail, and prairie junegrass. 



While blue grama spreads naturally from seed, its most effective 

 method of increase is by tillering, or the lateral spread of established 

 clumps through the development of new shoots at the outside vdgv. 

 Rapid expansion by this process normally offsets the natural death 

 losses from old age and other causes. 



Artificial reseeding of blue grama has been tested extensively on 

 New Mexico ranges. M. M. Hoover, of the Soil Conservation Service, 

 found that 3 to 4 pounds per acre of clean, viable seed planted in rows, 

 or 5 to 8 pounds broadcast, is sufficient to produce a good stand under 

 favorable conditions. For best results the seed should be covered 

 uniformly with soil to a depth of not more than 1 inch nor less than 

 one-half inch. Recent tests by the Bureau of Plant Industry indicate 

 that where soils are light and sandy and tend to blow readily, a prepara- 

 tory cover crop of close-drilled Sudan grass, sorgo, or other sorghum, 

 mowed so as to leave most of the hay on the land and a protective 

 stubble 8 to 12 inches high, provides a safer and more desirable seed- 

 bed for planting blue grama the following year. In some Localities in 

 eastern New Mexico blue grama has been successfully established on 

 abandoned plowed lands by mowing a nearby good stand of blue 

 grama and disking tin 4 mixture of seed, chaff, and hay into the soil. 

 With all of these methods the minimum requirements for successful 

 reseeding are: (1) Stabilized soil, (2) viable seed, (3) straw, stalk. 

 hay, or soil mulch covering the seed, and (4) sufficient soil moisture for 

 germination and growth. 



