CEREAL CULTIVATION WESTERN AREA 417 



to be well adapted to small farms (Fig. 138). The power 

 for operating the machine is now sometimes made inde- 

 pendent of the propelling power, which method is ap- 

 plied even in self-binders. 



In hilly districts and in other localities where shattering 

 varieties are grown, the self-binder is employed. Some- 



FIG. 138. The Moscow small combined harvester- thrasher 

 at Moscow, Idaho. 



times a wide-cut push binder is used, propelled like the 

 header. 



443. Merits of the different methods. It is chiefly 

 because of rapidity and economy of operation on large 

 farms that the combined machine has come into such 

 general use. This machine permits the return of all 

 straw to the soil, a particular advantage where the ex- 

 haustive summer fallow system of cropping is practiced. 

 It is believed that the maintenance of dry-land wheat- 

 farming for over a generation, without manuring, has 

 been made possible by the organic matter added to the 

 soil, as a result of the heading method of harvesting. 



2E 



