TILLAGE 67 S 



seldom advisable in humid regions, owing to the danger 

 of puddling the subsoil, or to the possibility of its remain- 

 ing too loose for best root development if the work is done 

 when the subsoil is dry enough not to puddle. 



579. Cultivators (Fig. 70). There are more types 

 of cultivators than of any other form of soil-working im- 

 plements. These may be grouped into (1) cultivators 

 proper; (2) leveler and harrow types of cultivators; (3) 

 seeder cultivators. These implements agree in their mode 

 of action on the soil, in that they lift up and move it side- 

 wise with a stirring action which loosens the structure and 

 cuts off weeds, and to a slight degree covers rubbish. How- 

 ever, the action is primarily a stirring one, and, in general, 

 it is much shallower than that of the plow. One impor- 

 tant fact should be kept in mind in cultural operations, 

 especially those just following the plowing; that is, the 

 work should be done when the soil is in the right moisture 

 condition. Particularly is this true in the pulverization 

 following the plowing. Plowing, if it is properly done, 

 leaves the soil in the best possible condition to be further 

 pulverized. It is properly moistened, and if the clods 

 are not shattered they are reasonably frail and may be 

 much more readily broken down than when they are 

 permitted to dry out. In drying they are somewhat 

 cemented together and thereby hardened. Not only is 

 it desirable in almost all cases to take advantage of this 

 condition of the soil, but the leveling and pulverizing 

 of the soil reduces drying and improves the character of 

 the seed bed. 



580. Cultivators proper. There is a great variety 

 in types and patterns of cultivators. They may be 

 divided into large shovel forms and small shovel forms, 

 and the duck-foot form. The first type has a few com- 



2x 



