18 



GENERAL ADVICE 



strong. Fig. 9 shows various types of model 

 surface plows. The one shown at the upper left- 

 hand is considered by Roberts, in his "Fertility 

 of the Land/' to be the ideal general -purpose 

 plow, as respects shape and method of con- 

 struction . 



PREPARATION OF THE SURFACE. Every pains 

 should be taken to prevent the surface of the land 

 from becoming crusty or baked, for we have al- 



9. Types of model plows. 



ready found that the hard surface establishes a 

 capillary connection with the moist soil beneath, 

 and is a means of passing off the water into the 

 atmosphere. Loose and mellow soil also has 

 more free plant -food, and provides the most con- 

 genial conditions for the growth of plants. If the 

 soil is a stiff clay, it is often advisable to plow 

 it or dig it in the fall, allowing it to lie rough 

 and loose all winter, so that the weathering 

 may pulverize and slake it. If the clay is very 



