vated crop and is being prepared for a fall-seeding. The gain in
time of preparing ground for oats in the spring makes the use of the
disk or cutaway harrow profitable on mellow corn-stubble land.

There is temptation to carry the substitution of the disk harrow for
the breaking-plow too far. Its use alone would have the same effect as
poor plowing, reducing the depth of the soil. The surface soil, down to
plow-depth, is the chief feeding-ground for plants because it is kept
in good tilth by organic matter and tillage. The depth of this soil
affects the amount of available plant-food and water. The duration of
time between deep plowings depends upon the soil and the crops.
Experience shows that when land has been broken for corn or potatoes or
beans or similar crop, the one plowing may be sufficient for a
succeeding crop. If grass is not seeded with the succeeding crop, it is
best to give another thorough plowing before seeding to grass in August
if the soil is heavy, but in naturally loose soils a disk harrow makes
a better seed-bed.

Two influences favor such undue dependence upon a disk harrow that a
soil may become shallow: the cost of preparing the seed-bed is reduced,
and the saving in moisture may give a better stand of plants when the
harrow takes the place of the plow. The immediate productiveness of a
crop is not an assurance that the method is right: consideration for
the good of the land must be shown. Depth of soil is a requirement of a
good agriculture, and deep plowing is a means to that end. The
looseness of the soil and the character of the season may make
substitution right in one instance and wrong in another. Deep soils,
well filled with organic matter, will bear shallow preparation of a
seed-bed more frequently than thin soils, and yet it is the latter that
may profit most by having its best part kept near the surface at the
time a new sod must be made. The disk harrow has some place as a
substitute for a plow, but when its use results in making a soil more
shallow, the harm is a most serious one.

Cultivation of Plants.--If a soil would remain mellow throughout the
season, there usually would be no reason to disturb the roots of plants
by any deep stirring, and all tillage would be only deep enough to make
a mulch of earth for the retention of moisture and to destroy all
weeds. Soils containing enough clay to make them retentive of moisture
become too compact when rains beat upon the ground, as u