8o 



SOILS AND FERTILIZERS 



One of the most successful of these machines consists 

 of two disks, one lower than the other and running in 

 different lines. The first cuts a slice of surface and 

 turns it into the deep furrow at its right. The second 

 disk running deeper throws the under portion over and 



CAPILLARITY 

 BROKEN AT PLANE 

 OF MAXIMUM 

 AMOUNT OF AIR 

 AND MOISTURE 



I 



FIG. 21. Shallow Plowing for Cereals. 



against the furrow turned by the first disk, both turn- 

 ing and pulverizing the soil. All trash and surface 

 weeds are thus effectually buried. 



