20 



BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. 



operator of a farm plans to increase the depth of his plowing, it is 

 usually necessary to make provision for more horsepower. With 

 the four- and five-horse crews it is altogether probable that the 

 plowing was done somewhat deeper than on the group of farms 

 using three horses per crew. An average day's work plowing varied 

 from 1.7 acres to 2 acres for the different crews. 



DISKING. 



Occasionally some disking is done preparatory to plowing. Again, 

 it is sometimes necessary to do the plowing when the soil is very dry. 

 Consequently the surface may be left in a lumpy condition. The disk 

 harrow can be run to advantage over such fields. This plan not only 

 reduces the rough surface, but it also has a tendency to bring the 





Bs^'y 



* * ' tj ■ Li <f ■ ' 

 to.- 



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y\W*'S frWv 



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Fig. 6. — Disking land after plowing. 



soil back to the proper tilth. The disk stands second to the plow in 

 effectiveness. 



The field records show that much more disking was done in the 

 Rocky Ford district than in either of the other sections under study. 

 This may have been due to a heavier soil and climatic differences. 

 (This feature will be discussed more fully under irrigation practice.) 

 Disking was done at the same time as plowing, or later. The average 

 width of disk used varied from 6.5 to 8.6 feet (fig. 6). 



The prevailing crew for disking consisted of one man and four 

 horses. Forty-three growers in Rocky Ford, 15 at Fort Morgan, and 

 15 at Greeley did the disking with a 1-4 crew. There were 15 farms 

 at Ilocky Ford that utilized a crew of one man and three horses. It 

 cost 54 cents more per aere to do the disking at Rocky Ford than at 



