TILLAGE 



677 



soil, where the aim is to kill weeds and create a thin sur- 

 face mulch. They are wide and are fitted with handles, 

 and therefore have an intermediate place between culti- 

 vators proper and harrows. They are much used for 

 intertillage of young crops. 



FIG. 71. Types of harrows: (1), spike-tooth; (2), spring-tooth; 

 (3), weeder; (4), double disk (note that the forward disks are 

 solid while the rear disks are of the cut-out type) ; (5) , spading 

 disk ; (6) , Acme. All these belong to the cultivator group of im- 

 plements. 



The Acme harrow consists of a series of twisted blades 

 which cut the soil and work it over. They are most 

 useful in the later stages of pulverization on soil relatively 

 free from stones. The Meeker harrow is a modified form 

 of disk, used primarily for pulverization. It consists of 

 a series of lines of small disks arranged on straight axles, 

 and is especially adapted to breaking up hard, lumpy soil. 



