SOILS IN DRY AREAS 77 



tions of tillage need not be questioned. This means 

 that where sage brush is plentiful and of vigorous 

 growth, the ability of the soil to produce abundantly 

 need not be questioned under correct methods of tillage 

 The soil constituents and the precipitation that will pro- 

 duce large and abundant sage brush will also produce 

 large crops of grain under proper conditions of tillage. 



Plants popularly known as "greasewood" and "rabbit 

 brush" grow on certain western soils. These indicate 

 that alkali salts are present in that degree that will in- 

 terfere with abundant production. Such soils may be 

 tilled with a certain degree of success, but not with that 

 degree of success that is to be looked for from, the tillage 

 of soils that are covered with an abundant growth of 

 sage brush of relatively large size in the shrubs. 



In other areas, especially those that are very sandy 

 in texture, the vegetation may be very sparse. The sage 

 brush that may be growing on these is dwarfish* and the 

 plants are relatively distant. Such growth does not 

 necessarily indicate any absence of the essential elements 

 of fertility in the soil, but rather the absence of moisture. 

 In those areas the production of grass is sparse in its 

 character, and good crops cannot usually be grown in the 

 absence of irrigation. 



The grasses which nature produces on the bench 

 lands of the west are one of the surest indications of the 

 possible production that may be looked for from the 

 judicious tillage of the lands that produce those grasses. 

 Where the native grasses form a sod that is reasonably 

 dense on the untilled prairie, the presence of a sufficient 

 rainfall for the production of good crops in a normal 

 season rieed not be questioned. Where, however, the 

 production of these grasses is sparse and limited, a light 

 rainfall relatively is to be looked for. The precise char- 

 acter of the grasses will vary with the soils and the 

 amount of the precipitation, but it may be safely assumed 



