Orange Grove, Showing Method of Basin Irrigation 



not effectively restrict evaporation, he 

 must resort throughout the entire year 

 to every method of cultivation, and 

 from year to year to the method of 

 crop rotation, to keep his ground in the 

 best possible condition for the largest 

 storage of ground water, from which 

 will follow also the largest return of 

 any one crop. In the arid region nature 

 comes to the aid of the farmer and 

 gives him a means of stopping the loss 

 of the precious moisture of which under 

 the best conditions he can scarcely con- 

 serve enough. 



When the farmers of America under- 

 stand how to store and keep water in 

 the ground they will have learned how 

 to grow larger crops. Our average 

 yield of wheat instead of being as it 

 now is fourteen bushels to the acre, will 

 then be nearer the average yield of 

 Great Britain, thirty-two bushels. 



Water control on slopes. — In regions 

 where steep slopes are cultivated the 

 methods appropriate to level fields find 

 their application also, but they are in- 

 sufficient, for the tendency of the water 

 to run off lessens the time of its contact 

 342 



with the surface, and thus increases the 

 proportion which escapes at the expense 

 of the proportion that is stored. ' In a 

 like degree erosion begins and is main- 

 tained on slopes, the soil is undercut 

 and removed, and the subsoil or rock 

 exposed. Forests would prevent this, 

 but if the steep slope is cleared for cul- 

 tivation it is necessary to substitute a 

 series of steps for the smoothly inclined 

 surface, in order to reduce these effects 

 to a minimum. 



This introduces a condition which is 

 not yet necessary in America to any 

 great extent, but which is general 

 throughout Europe and Asia, namely, 

 terracing. The object is to catch rain 

 and snow on a level. The level may 

 be the furrows of a plow or of a har- 

 row, provided the slope be so gentle 

 that these suffice to hold back the water 

 and prevent it from running and gully- 

 ing the fields. On steeper slopes the 

 harrow and the plow are inadequate, 

 and the farmer is obliged to introduce 

 low steps or terraces which vary in 

 character from a little bank of sward 

 to walls of stone. The fields above the 



