HOW TO GRAZE BLUE GRAMA OX SOUTHWESTERN RANGES O 



and mostly near the surface, bind the surface soil very effectively. 

 Only when the stand is markedly reduced by heavy grazing or drought 

 or a combination of both does blue grama fail to give adequate soil 

 protection. When that occurs, however, it is very difficult to check 

 the topsoil movement on the compact clay loams on which blue grama 

 often grows. 



Proper Utilization 



Where it is dominant, blue grama is a key indicator of range 

 utilization; that is. proper use of blue grama is regarded as indicating 

 proper use of the associated plants and the range as a whole. Where it 

 grows in appreciable volume with some other important forage plant, 

 such as black grama, blue grama is so highly relished that in most 

 instances it is the first plant to reach the limit of proper utilization 

 (%. 2). 



The resistance of blue grama to grazing appears to be approximately 

 the same throughout its range in the Southwest. Ordinarily the 





at 



Figure 2. — A short-grass blue and black grama range about properly utilized. 

 Blue grama is the utilization-indicator plant and has been cropped to about 

 2 inches above the ground, and 25 percent of the flower, stalks have been left 

 standing. 



stubble height of blue grama after grazing should not be less than 

 2 inches at the end of the grazing season, and, in addition. 25 or 30 

 percent of the flower stalks should be left ungrazed. This degree of 

 utilization by autumn on summer ranges and by late spring on either 

 year-long or winter ranges will insure range maintenance and im- 

 provement and stability of the soil. 



On such a properly grazed blue grama range with average forage 

 growth about 40 percent of the actual volume of blue grama herbage 

 has been removed at the end of the grazing season. To most ob- 

 servers this would appear to represent about 70-percent utilization. 

 However, as is true with most range grasses, a disproportionately 

 large share of the forage of blue grama is in the basal leaf growth close 

 to the ground, as shown in figure 3. 



On deteriorated ranges, where blue grama, which should be the 

 climax vegetation, is subordinate to such inferior species as broom 



