330 



SOIL PHYSICS AND MANAGEMENT 



FIG. 142. Lister for preparing the ground and planting corn. Used chiefly in the semi- 

 arid regions. (Moline Plow Company.) 



A reversible disk for hillside plowing has some advantages over the 

 ordinary reversible mold-board plow. 



A deep tilling, double disk plow for stirring the ground to a 

 depth of 16 to 18 inches is used in some sections. This does noi, 

 however, bury the surface soil to so great a depth as would be indi- 

 cated, but mixes this deeper soil with the surface to a greater or less 

 extent. The disk plow cannot be used in stony land successfully, 

 particularly where the stones are firmly set in the soil. 



The lister (Fig. 142) is a plow used particularly in semi-arid 

 regions for the preparation of the ground for corn planting, and 

 even for other crops. It is a double mold-board plow, and when 

 used opens a furrow in which the corn is planted. It ridges the 

 land and gives the soil an excellent chance to weather (Fig. 143). 



The subsoil plow (Fig. 144) is used to loosen the soil in the 

 bottom of a furrow made by the ordinary plow. It consists of a 

 shoe which merely raises the soil, but does not throw it out. 



