22 BULLETIN 997, U. S. DEPARTMENT OF AGRICULTURE. 



behind a disk, and 28 per cent independent of the disk. The size 

 of the tractor had a direct bearing upon the combination used, for 

 the 3-plow outfits were able to pull greater loads than the 2-plow 

 machines. Only 61 per cent of the work done with 2-plow tractors 

 was done with harrows, rollers, etc., behind disks, while 92 per cent 

 of that done with 3-plow tractors was done behind disks. 



Farms where all work 'previous to planting was done with tractors.— 

 While the larger part of the plowing and disking and a considerable 

 portion of the lighter work of harrowing, planking, rolling, and 

 packing on these farms was done with tractors, on only 39 of the 

 286 — 14 per cent of the total — was all of the work of preparing the 

 seed bed done with tractors. Even on farms whose operators 

 considered their machines suitable for all this work, horses usually 

 did part of it. 



Most of the farms where tractors were used exclusively were 

 operated by one man alone. Where an extra man was available a 

 part of this work was nearly always done with horses. 



The seed-bed preparation was done with tractors entirely on 21 

 per cent of the farms with less than 160 crop acres, but horses were 

 used for some seed bed preparation on all but 9 per cent of the farms 

 with 160 or more crop acres. Thirty-four of these 39 men operated 

 2-plow outfits and 5 of them 3-plow outfits. Thus 20 per cent of 

 all the men who owned 2-plow machines and only 5 per cent of those 

 who owned 3-plow machines did all of this work with tractors. 

 Even though a larger percentage of the men on smaller farms owned 

 2-plow machines, apparently the greater versatility of the smaller 

 machines made them more satisfactory for all the kinds of work 

 required in preparing the seed bed. 



Cutting grain. — Seven of the 286 men interviewed either raised 

 no small grain or paid to have it cut by others. The kinds of power 

 used by the remaining 279 were as follows: 



108 or 39 per cent used tractors only. 

 22 or 8 per cent used tractors and horses. 

 149 or 53 per cent used horses only. 



The 22 men who used both tractors and horses did not always use 

 them simultaneously. More often the two sources of power were used 

 at different times, one on oats and the other on wheat for example. 



The size of the farm apparently had little to do with the kind of 

 power used in cutting grain. Forty per cent of the men who had 

 less than 160 crop acres, 42 per cent of those with 160 to 239 crop 

 acres, and 33 per cent of those with 240 or more crop acres cut all 

 their grain with tractors. The size of the tractor however, did have 

 some influence on its use for cutting grain. Fifty-four per cent of 

 the grain was cut with tractors on the farms where 2-plow machines 

 were owned and only 26 per cent on the farms where 3-plow machines 



