SOIL IMPROVEMENT 



97 



A GOOD HARROW 



The Harrow. In the preparation of land for a crop, the plow 

 is usually followed by the harrow or drag. The chief office of the 

 harrow is to pulverize 

 finely the surface soil. 

 It secures a fine, even 

 surface free from clods, 

 prepares a shallow seed 

 bed, covers seeds, and 

 destroys weeds. 



The Roller. On land which has been seeded in grain or grass, 

 the roller often follows the plow and the harrow. Farmers claim 



that its use gives a bet- 

 ter stand and larger 

 yield. Rolling compacts 

 the soil. It makes the 

 soil-spaces smaller, and 

 causes water to rise by 

 capillarity. Thus seeds 

 are better supplied with 



A GOOD ROLLER moisture ; they germi- 



nate more quickly, and form stronger plants. 



Sometimes, to avoid leaving the surface' too compact, the 

 roller is followed after 

 a time by the harrow to 

 admit air and to form 

 a soil-mulch. 



Purposes of Crop Cul- 

 tivation. After the soil 



On the left the soil is compacted by rolling; on the 

 right the roller has been followed by the harrow, to 

 form a soil-mulch. 



is prepared with plow, 



harrow, and roller, and 



the crop is planted, cultivation is continued with harrow, hoe, and 



other tools. Why do we cultivate the growing crops ? 



