DRY-FARMING 



gray foliage ; while here and there in the 

 mesas you note the dark green of the rab- 

 bit-brush and scattered tufts of different 

 hardy grasses. Along the foot-hills 

 cedars are seen marking outcrops on 

 stony soil. Far down below in the valleys 

 on the heavy salt-filled soils the grease- 

 wood becomes the dominant shrub and the 

 sedge strives with the saltbush according 

 as the moisture is scant or the alkali 

 abundant. To the south of this region 

 the sage-brush is replaced by the creosote 

 bush; while along the water-courses wil- 

 lows and cottonwoods are common; but, 

 aside from these, the arable lands of the 

 Great Basin are treeless and readily 

 brought under the plow. 



Fertility. 



It is commonly held that the con- 

 tinuous growth of any one crop, such as 

 wheat, will rapidly reduce and finally ex- 

 176 



