14 
BULLETIN" 3, U. S. DEPARTMENT OF AGRICULTURE. 
Table V. — A normal day's work in plowing stubble and sod with traction engine, giving 
the average acreage reported, according to the horsepower of tractor — Continued. 
PLOWING SOD. 
[Net hours in the field, 11.32; net hours in motion, 8.83.] 
Horsepower of engine. 
Width 
of cut. 
Depth. 
Reported 
acreage. 
Number 
averaged. 
Adjusted 
acreage. 
15 
Feet. 
5.2 
6.1 
7.9 
9.-8 
9.7 
13.0 
13.8 
8.4 
9.3 
Inches. 
4.4 
4.4 
4.2 
4.4 
4.5 
4.7 
4.3 
4.5 
5.4 
10.3 
13.5 
15.7 
18.3 
20.3 
27.0 
28.2 
17.2 
18.0 
4 
16 
12 
43 
27 
24 
11 
10 
6 
9.7 
20 
13.0 
22 
14.3 
25 
16.2 
30 
19.5 
32 
20.8 
40 
26.0 
45 
29.2 
60 
35.0 
HARROWING. 
Data were accumulated on the operation of harrowing with the 
spike-tooth or smoothing type, the spring-tooth type, and the disk 
or pulverizing type. With the spike-tooth harrow it appears that 
41 per cent of farmers use two horses, 29 per cent use four horses, 
and 23 per cent use three horses. Only 7 per cent use other numbers 
of horses in their teams. The most popular width of harrow is 10 
feet with 17 per cent, the 8-foot width being second with 15 per 
cent. In other sizes, from 4 to 26 feet, the percentage in use is 
quite evenly distributed between the limits of 4 to 7 per cent. The 
draft of this implement is comparatively light for its width, so that 
the harrowing of large areas daily or the careful preparation of 
smaller areas is possible and economical. 
Analysis of the data showed that on freshly plowed land about 20 
per cent less can be covered per day than on well-packed fields. The 
average area reported for 3-horse outfits was less than would be 
expected from an increase of 50 per cent in power, but the width was 
not increased in proportion. With the four horses the width reported 
averaged more than twice that of two horses and showed an acreage 
more than 100 per cent greater. With the spike- tooth harrow, 
which is an implement of comparatively light draft, those farms 
which can economically utilize more horses in the team throughout 
the season can also secure greater efficiency per horse in harrowing 
than is commonly obtained by the majority who use the smoothing 
harrow with one or two horses. When the data for spike-tooth 
harrows were consolidated by widths, it was seen that the acreage 
covered per day per horse and per foot in width increased directly 
in proportion to the width. In general, each foot in width of the 
harrow should cover from 1.5 to 1.75 acres daily, and each horse 
could be loaded with 4J feet in width and go once over from 6 to 6.5 
acres without inconvenience on freshly plowed land. On well-packed 
land each foot in width should harrow from 1.75 to 2 acres and each 
horse could be expected to work from 7.25 to 8 acres. 
