392 PRODUCTIVE FARMING 



short time; it can be done in very hot weather without injury 

 to draft animals ; double cropping is thus often accomplished ; 

 one man can farm more acres; hired help is not so necessary; 

 more hours in the day are likely to be used. 



One of the disadvantages of the tractor in some sections, 

 is the difficulty in using it when the soil is rather wet, if it is 

 naturally heavy soil. Spring work may be delayed while 

 waiting for wet parts of a field to become dry enough to use 

 a heavy tractor. This difficulty is less serious with cater- 



FIG. 245. Opening road drains with scraper and tractor. (Cleveland Tractor Co.) 



pillar tractors. The moisture can be rapidly reduced by har- 

 rowing the field with a team before plowing. 



Sizes of Tractors for Plowing. The very large tractors, 

 pulling six to twelve or more breaker bottoms, were once used 

 on the northwestern plains, but these are now seldom found. 

 Those pulling two, three, four or five are far more popular. 

 The two- or three-plow sizes are most rapidly coming into 

 favor. The original investment is less; the cost of opera- 

 tion is low; the loss of time from troubles is less serious; 

 and the small-sized tractor is more suitable for many 

 other farm operations. 



Cost of Plowing With Tractors. There are a number of 

 elements or factors to be considered in calculating the cost 



