46 



ARID AGRICULTURE. 



SUB-SOU. 



FLOWING 



into tilth before the first crop is planted. Some 

 soils may be so shallow that it is not well to plow 

 them deep. Where irrigation is practiced in. 

 some of our drier regions where the soil is very 

 poor in vegetable matter, merely discing two or 

 three inches of the surface often gives a better 

 first crop of grain than plowing. Such soils 

 must be irrigated often and carefully because the 

 soil may wash and the area for storage of moist- 

 ure is so small that it dries out quickly. Gener- 

 ally a soil that is suitable for dry farming is one 

 which may be plowed deeply. 



Subsoiling is done by using a digger which 

 follows the plow and tears up a few inches of the 

 furrow sole or by means of a mole plow which is 

 run underneath the furrow and lifts and breaks 

 up the subsoil to the depth of fifteen inches or 

 eighteen inches. It is expensive to prepare 

 ground by subsoiling and is not recommended 

 for general practice. Our rainfall is so small 

 that so large a reservoir is not needed for storage 

 of moisture and where irrigation is practiced 

 there seems no advantage from filling so much 

 loose soil with water at one time. There are 

 places where subsoiling is advisable, and it often 

 proves profitable for root crops or preparation of 

 land for tree planting. 



SECOND The second time the soil is turned, plow 



about two inches shallower than the first plow- 



