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CORN 



Fourth. The numerous weed seeds present in the surface soil 

 are induced to germinate because of the admittance of warm air. They 

 can be destroyed later by vigorous harrowing. 



Fifth. Helps to form a mulch and thus conserves moisture. 



Sod which is not plowed until spring, even though it is turned 

 over as early as the weather permits, depends chiefly upon the disc 

 for preparation. The firing of sod corn in July can usually be traced 

 directly to spring plowing or an insufficient discing of fall plowing. 

 Large pieces of turf admit the air and allow moisture to be taken di- 

 rectly from the sub-soil. 



COMBINED PULVERIZER AND PACKER. 

 Best adapted to grip clods and crush them. 



Special Harrows. For stony land, or in timbered sections where 

 the teeth are liable to catch on roots, the spring-tooth harrow has a 

 decided value. The teeth can be set to gouge forward and hence 

 tear up sod more than the fixed tooth harrow. The later manufac- 

 turers mount the frame on runners, which does away with bouncing 

 effect common in spring-tooth harrows when set too deep. Some are 

 also mounted on low trucks with the same end in view. 



Curved knife harrows and drag pulverizers are used to some 

 extent, but where corn stalks are present in any number they ride 

 over them too easily. For fining the surface of a field which has 

 already been well worked, the pulverizer is especially well suited. 



Smoothing Harrow. The rigid, straight-toothed harrow does effi- 

 cient work on ground free from trash. Because of an excess of stalks 

 the slant tooth and lever harrows are more practical and popular. 



