CULTIVATED CROPS 73 



Figure 30. — A two-row cultivator at work. Many farmers are now using these 

 larger machines. One man can do nearly twice as much work with such a ma- 

 chine as he can with a one-row cultivator. 



is to destroy weeds. The smaller the weeds are the easier 

 it is to kill them. On this account it is important that 

 soil be so worked that most of the weeds are destroyed 

 before the corn is planted, as it is difficult to jcultivate very 

 young corn and the weeds may get ahead of the corn. It 

 is also cheaper to cultivate with a large harrow than with 

 a cultivator. Of course corn may be harrowed after it is 

 planted or even after it is up, but the less harrowing neces- 

 sary at this time the better, as more or less corn is injured 

 every time the field is harrowed. 



In fields well prepared before corn is planted, very few 

 weeds will be seen, and those appearing are small and easily 

 killed at the first cultivation. 



Other Objects. — Cultivation aerates the soil, i. e., opens 

 it and lets air into it, thereby stimulating the decomposition 

 of vegetable matter and liberating more plant food. 



Cultivation also keeps the soil loose, so that rain which 

 falls may be readily absorbed, thus making a larger supply 

 upon which to draw when a dry season comes. 

 Questions: •"; 



1. What is the main reason for cultivating com? 



2. In what two ways is moisture taken from the soil? 



3. How does cultivation check evaporation? 

 'I. Give another reason for cultivating com. 



