58 CORN CULTURE 



III. Cultivate the soil. This is done not only to kill weeds 

 but also because tillage is manure. The stirring of the soil 

 is one of the means of changing imavailable plant food into 

 available form. 



Cultivation also makes a mulch of the fine dry soil that con- 

 tributes in a degree to conserve the moisture in the soil. 



