366 DRY LAND FARMING 



much of the land is covered with sage brush of more or 

 less vigor in its growth. Where shrub life can maintain its 

 hold upon the soil unaided under such conditions, there 

 would seem to be no hazard in assuming that higher 

 forms of shrub and even of tree life can be produced 

 under judicious cultivation. Under very dry conditions 

 cedars maintain an existence in the Great Basin and the 

 mesquite in Arizona under conditions equally dry. (2) 

 In the very few instances in which attempts have 

 been made to grow trees and shrubs, a fair measure of 

 success has followed where the work has been judiciously 

 done. (3) It would seem safe to claim that wherever 

 grain crops may be grown successfully the measure of 

 the precipitation that will grow grain will make it pos- 

 sible also to grow certain forms of trees and shrubs, 

 where the land has been properly prepared before plant- 

 ing the trees, and where proper care is given after the 

 planting. 



That the results from growing trees and fruits over 

 so wide an area will differ greatly is in no way surprising. 

 They are the outcome of a difference in soil, in the amount 

 of the precipitation and in temperature. Nearly all of the 

 soil in the entire dry area is well adapted to the growing 

 of fruit. Especially where the real volcanic ash soils 

 prevail is the adaptation superlative. The tendency to 

 fruiting in the trees grown on these soils is remarkable. 

 Of course where the precipitation is the highest, trees 

 and fruits are the most easily grown in the absence of 

 irrigation. For instance, in the upper valleys of the Co- 

 lumbia and its branches, fruit may be readily grown in 

 the absence of irrigation, but it cannot be thus grown in 

 the lower valleys of the same. West of the Rocky Moun- 

 tains only the more hardy fruits can be grown, whereas 

 east of the same, varieties much less hardy are quite easily 

 grown. 



