82 



SOILS AND FERTILIZERS 



These plants, then, are often best served by shallow 

 plowing a depth of from three to six inches being 

 sufficient. The corn plant, on the other hand, has a 

 more extensive and deeper system of roots and thrives 

 better on plowing not less than eight inches in depth. 

 For the alfalfa plant, which has a long tap root, the plow- 

 ing need not be limited as to depth. 



Connection with Subsoil. Whatever the depth of 

 planting determined on as best, the plowed surface 



should be brought into 

 close contact with the 

 subsoil so that capillarity 

 which was broken by the 

 plowing may be reestab- 

 lished. The sod or the 

 trash that is turned under 

 often keeps the plowed 



FIG. 23. Roller. -i r 



soil from coming in con- 

 tact with the undersoil. The plowed surface then 

 soon dries out and crop raising is almost an impos- 





FIG. 24. Soil as the Packer leaves it. 



