PREPARING THEf SEED-BED FOR CORN 235 



planting cannot be overestimated." Large lumps massed 

 together have between them much air space. Such a 

 condition not only allows the rain water to percolate to 

 lower depths too rapidly, but it admits too much surface 

 air which rapidly dries out the lumps and robs the seed-bed 

 of its moisture. A seed-bed must consist of well-firmed 

 fine earth if roots are to penetrate it readily. For pulver- 

 izing sod, stubble or corn-stalk land, the fuU-bladed disk 

 is preferable. For compact soils, the cutaway disk is a 

 good implement. 



286. "the smoothing harrow. — On land that is free 

 from large clods and trash some form of smoothing harrow 

 is the best implement for smoothing the surface, killing 

 weeds, and conserving moisture. The adjustable slant- 

 tooth and lever forms are more practical and popular. 

 Farmers with sufficient acreage to justify it are advised 

 to use the large foiu--section harrows because of the high 

 price of farm labor. With such an implement one man and 

 four horses can harrow from thirty to forty acres in a 

 day. These harrows should be more generally used. They 

 leave the ground in a most excellent state of tilth. 



287. Special harrows. — Other types of harrows used 

 for special piu-poses in the preparation of corn land are 

 the spring-tooth harrow, the acme or curved-knife form 

 of harrow, the weeder and the meeker harrow. The 

 spring-tooth harrow has a decided value for stony^land or 

 in timbered sections where the teeth are likely to catch 

 on roots. The acme harrow is most useful in the later 

 stages of pulverization on soil free from stone and stalks. 

 It consists of a series of twisted blades which cut the soil 

 and work it over. Where stalks are present they ride over 

 them too easily. The weeder is a modified form of spring- , 

 toothed harrow adapted primarily to killing weeds. It 



