4 BULLETIN 412, U. S. DEPARTMENT OF AGRICULTURE. 
In Table III is shown the duty of sulky plows in western New York 
working on sod and on stubble. Few New York farmers attempt to 
operate sulky plows with two horses. The load is entirely too great 
for two horses, and only poor plowing can be done with less than 
three horses. The 14-inch plow is most commonly used on the 
sulky in this section, while the 16-inch is the most common for the 
average of all farmers in the country. In the soils of New York the 
14-inch sulky is an ample load for three horses. From 5 to 10 per 
cent more work can be done on stubble than on sod with the sulky 
plow. 
Table III. — A fair day's work for sulky plows drawn by three horses on sod and on stubble. 
Horses. 
Width. 
On sod. 
On stubble. 
Acres. 
Number 
averaged. 
Acres. 
Number 
averaged. 
3 
3 
3 
Inches. 
12 
14 
16 
1.95 
2.08 
2.26 
86 
105 
51 
2.11 
2.20 
2.37 
86 
115 
42 
HARROWING. 
The spike- tooth or smoothing harrow can be operated with 
2-horse or 3-horse teams in a wide range of widths, as it is an imple- 
ment of comparatively light draft. Three horses accomplish from 
10 to 15 per cent more work on the same width of harrow than two 
horses do. Table IV gives the average duty for the spike-tooth 
harrow for widths ranging from 5 to 12 feet for 2-horse and 3-horse 
teams. 
Table IV. — A fair day's ivorh for the spike-tooth harrovj ivith 2-horse and 3-horse teams. 
Width. 
2-horse teams. 
3-horse teams. 
Acres. 
Number, 
averaged. 
Acres. 
Number 
averaged. 
Feet. 
5 
6 
7 
8 
9 
10 
12 
11.2 
11.1 
12.0 
13.0 
13.8 
16.1 
14.8 
15 
87 
102 
199 
43 
102 
20 
11.0 
11.9 
13.2 
14.1 
16.4 
17.3 
19.1 
2 
27 
33 
75 
48 
80 
38 
Where two horses are required to draw widths greater than 10 
feet they appear to be overloaded so that their daily efficiency is 
reduced. 
The spring-tooth harrow is used to do the hard, preliminary work 
of fitting the land after plowing. It is adapted to soils which are too 
