116 



DRY FARMING 



is not a harrow or cultivator but only a seeder, 

 (Fig. 43D). 



87. Drag or Smoothing Harrows. — The purpose of the 

 drag or smoothing harrow is to prepare a level and uni- 

 form surface after other kinds of tillage, or to destroy 

 j^oung weeds by exposing their roots to the sun and air, 

 or to form a mulch on the surface to conserve moisture 

 or to aid in covering the seed after sowing. The drag 

 harrow may be heavy or light, have wooden or steel 

 frames and the teeth may be stationary (Fig. 41 A) or 



Fig. 41. — Types of Harrows. 



(a) Steel harrow; (b) Adjustable harrow; (c) Spring tooth harrow: 

 (d) Acme harrow. 



adjustable (Fig. 41B). The light lever harrow with 

 teeth sloping slightly backward is frequently used in 

 the growing crop of grain, corn or potatoes for killing 

 small weeds. 



The spring tooth harrow (Fig. 41 C) has the same 

 function as the spring tooth cultivator. It is lighter in 

 draft but less efficient. 



The acme harrow (Fig. 41D) smooths the surface, cuts 

 small weeds and forms a mulch, but it is not well 

 adapted to general use under average farm conditions. 



