Thorough Tieeage System tor Plains or Colorado. 5 
should be the furrow, whether the plow be a mold board or a disc 
plow. 
2. Harrowing the Ground. —Harrowing is the process of 
stirring the soil by some form of a toothed or circle knife imple¬ 
ment. Its purpose is the pulverizing of the soil, reducing it to 
finer tilth than the plow left it, filling the interstices left by the plow 
and thus leveling the soil. I believe that the spike toothed harrow 
is a superior implement for pulverizing after the plow. It should 
follow as near after the plow as possible so as to prevent loss of 
moisture by evaporation from the newly plowed earth and the for¬ 
mation of clods. Each half day’s plowing should be harrowed 
that same half day in which it is plowed. 
Ground that is harrowed first lengthwise with the plowing will 
retain its moisture better, since it regularly and evenly fills the in¬ 
terstices or openings at the bottom edge of each furrow slice. Al¬ 
ways first harrow lengthwise and later cross harrow if the ground 
is not in fine enough tilth for the seed. Ground that is inclined to 
be cloddy should be worked with the disc harrow instead of the 
spike tooth, double disking or half lapping lengthwise with the fur¬ 
rows. See that your disc is the proper size to do the most effec¬ 
tive work in pulverizing the soil. A fourteen to sixteen-inch disc 
generally pulverizes better than an eighteen or twenty-inch disc, 
and the draft is correspondingly greater. Experiments seem to 
indicate that the smaller diameter discs are better adapted for 
farming conditions on the Colorado plains than the larger diameter 
discs. Experiments conducted by experiment stations and by Mr. 
H. W. Campbell of Lincoln, Nebraska, show that disking grain 
ground after the harvester prevents loss of moisture on stubble 
ground through too rapid evaporation, and prepares the ground for 
the ready absorption of rain. 
3. Sub-Sureace Packer. —This tool consists of a series of 
wedge faced wheels attached to a common axle. These wedge¬ 
faced disks are 18 inches in diameter and placed vertically on the 
shaft 6 inches apart. This machine is better than a smooth roller 
for a roller firms the surface soil with little or no effect upon the 
under or sub-surface soil. The packer firms the soil in the lower 
portion of the furrow slice, restoring the capillariety where plow¬ 
ing had arrested it. This firmed under-surface soil is enabled to 
draw moisture from below and give good normal root development. 
In case a sub-surface packer is not obtainable, a corrugated roller 
can be used. It firms the ground but not to the depth which the 
sub-surface packer does. These packers should be followed by a 
smoothing harrow to produce an earth mulch which shall arrest 
capillarity and thereby check evaporation. 
A spike toothed harrow with lever attachments for regulating 
