﻿12 BULLETIN 3, IT. S. DEPAETMEISTT OF AGEICULTUBE. 



greater than 8 inches, whereas for the walking, sulky, and gang 

 plows, respectively, the percentage plowing at 8 inches deep is 17, 12, 

 and 5. Four horses are used by 58 per cent, five horses by 25 per cent, 

 and six horses by 10 per cent. Many find it necessary to use more 

 than six horses where the same horses work all day or on very heavy 

 plowing. In the Central West gang plowing is often done with four 

 horses working half days alternately. This inquiry has not sepa- 

 rated these from the general averages in the table, since it was not 

 feasible to provide space for this practice in the blank on which the 

 information was obtained. 



When the gang-plow data were brought together by widths with 

 averaged depths and vice versa, it would seem that the users of the 

 wider plows had heavier horses and also did not plow so deep. With 

 increased power at a given width, the depth increased. In gen- 

 eral, the depth decreased as the width increased, while the acreages 

 per day and per horse increased, and conversely. The analysis in- 

 dicated that each 1,000 pounds of horse is loaded with 29 square 

 inches in a cross section of the furrow with four horses, 25 square 

 inches with five horses, and 23 square inches with six horses, and that 

 these teams plow 0.86, 0.79, and 0.68 acre per day per 1,000 pounds 

 of horse, respectively. 



A comparison of the reported acreages per 1,000 pounds of horse 

 for sulky and gang plows indicates that the gang plows are somewhat 

 more efficient when working at the same widths and depths. The 

 fact that a smaller proportion of farmers use 4-horse teams on gang 

 plows than use 3-horse teams on sulky plows indicates that four 

 horses are much overloaded by a gang plow. This conclusion is also 

 borne out by the fact that plowing deep is not so general with gang 

 plows, as well as by the general opinion of farmers in regions where 

 gang plows are used. The operation of plowing is a severe tax on 

 horses, but its magnitude and cost encourage the tendency to load 

 them to the limit of their capacity. The greater acreages plowed by 

 the gang type are due in part to the more level land, to freedom from 

 obstructions in the soil, and to the greater speed required of horses 

 in the sections where sulky and gang plows are used. They may also 

 be accounted for by the mechanical construction of the sulky frame, 

 which makes it possible to hold the plow to its rated or other desired 

 width more uniformly than can be done with walking plows when the 

 horses are overloaded. In plowing, anything over 25 square inches 

 in cross section and 0.65 acre daily per 1,000 pounds of horse appears 

 generally to be an overload. 



In Table IV data for gang plows have been compiled in a manner 

 similar to that for Tables II and III. The daily duty for any desired 

 unit of equipment and depth can be readily ascertained by inspec- 

 tion of the fourth and fifth columns. 



