Having considered, as thoroughly as the limited space available
permitted, the matter of plant foods, we must proceed to the equally
important one of how properly to set the table, on or rather in, which
they must be placed, before the plants can
use them.
As was noted in the first part of the preceding chapter, most tillable
soils contain the necessary plant food elements to a considerable
extent, but only in a very limited degree in _available_ forms.
They are locked up in the soil larder, and only after undergoing
physical and chemical changes may be taken up by the feeding roots of
plants. They are unlocked only by the disintegration and decomposition
of the soil particles, under the influence of cultivation--or
mechanical breaking up--and the access of water, air and heat.
The great importance of the part the soil must play in every garden
operation is therefore readily seen. In the first place, it is required
to furnish all the plant food elements--some seven in number, beside
the three, nitrogen, phosphoric acid and potash, already mentioned. In
the second, it must hold the moisture in which these foods must be
either dissolved or suspended before plant roots can take them up.
The soil is naturally classified in two ways: first, as to the amount
of plant food contained; second, as to its mechanical condition--the
relative proportions of sand, decomposed stone and clay, of which it is
made up, and also the degree to which it has been broken up by
cultivation.
The approximate amount of available plant food already contained in the
soil can be determined satisfactorily only by experiment. As before
stated, however, almost without exception they will need liberal
manuring to produce good garden crops. I shall therefore not go further
into the first classification of soils mentioned.
Of soils, according to their variation in mechanical texture, I shall
mention only the three which the home gardener is likely to encounter.
Rocks are the original basis of all soils, and according to the degree
of fineness to which they have been reduced, through centuries of
decomposition by air, moisture and frost, they are known as gravelly,
sandy or clayey soils.
CLAY SOILS are stiff, wet, heavy and usually "cold." For garden
purposes, until properly transformed, they hold too much water, are
difficult to handle, and are "late." But even if there be no choice but
a clay soil for the home garden, the gardener need not be discouraged.
By proper treatment it may be brought into excellent condition for
growing vegetables, and will produce some sorts, such as celery, better
than any warm, light, "garden" soil. The first thing to do with the
clay soil garden, is to have it thoroughly drained. For the small
amount of ground usually required for a home garden, this will entail
no great expense. Under ordinary conditions, a half-acre garden could
be under-drained for from $25 to $50--probably nearer the first figure.
The drains--round drain tile, with collars--should be placed at least
three feet deep, and if they can be put four, it will be much better.
The lines should be, for the former depth, twenty to thirty feet apart,
according to character of the soil; if four feet deep, they will
accomplish just as much if put thirty to fifty feet apart--so it pays
to put them in deep. For small areas 2-1/2-inch land tile will do. The
round style gives the best satisfaction and will prove cheapest in the
end. The outlet should of course be at the lowest point of land, and
all drains, main and laterals, should fall slightly, but without
exception, toward this point. Before undertaking to put in the drains,
even on a small area, it will pay well to read some good book on the
subject, such as Draining for Profit and Draining for Health, by
Waring.
But drain--if your land requires it. It will increase the
productiveness of your garden at least 50 to 100 per cent.--and such an
increase, as you can readily see, will pay a very handsome annual
dividend on the cost of draining. Moreover, the draining system, if
properly put in, will practically never need renewal.
On land that has a stiff or clay sub-soil, it will pay well to break
this up--thus making it more possible for the water to soak down
through the surface soil rapidly--by using the sub-soil plow. (See
Chapter V.)
The third way to improve clay soils is by using coarse vegetable
manures, large quantities of stable, manures, ashes, chips, sawdust,
sand, or any similar materials, which will tend to break up and lighten
the soil mechanically. Lime and land plaster are also valuable, as they
cause chemical changes which tend to break up clayey soils.
The fourth thing to do in treating a garden of heavy soil is to plow,
ridging up as much as possible, in the fall, thus leaving the soil
exposed to the pulverizing influences of weather and frost. Usually it
will not need replowing in the spring. If not plowed until the spring,
care should be taken not to plow until it has dried out sufficiently to
crumble from the plow, instead of making a wet, pasty furrow.
The owner of a clayey garden has one big consolation. It will not let
his plant food go to waste. It will hold manures and fertilizers
incorporated with it longer than any other soil.
SANDY SOIL is, as the term implies, composed largely of sand, and is
the reverse of clay soil. So, also, with the treatment. It should be so
handled as to be kept as compact as possible. The use of a heavy
roller, as frequently as possible, will prove very beneficial. Sowing
or planting should follow immediately after plowing, and fertilizers or
manures should be applied only immediately before.
If clay soil is obtainable nearby, a small area of sandy soil, such as
is required for the garden, can be made into excellent soil by the
addition of the former, applied as you would manure. Plow the garden in
the fall and spread the clay soil on evenly, harrowing in with a disc
in the spring. The result will be as beneficial as that of an equal
dressing of good manure--and will be permanent.
It is one of the valuable qualities of lime, and also of gypsum to even
a greater extent, that while it helps a clay soil, it is equally
valuable for a sandy one. The same is true of ashes and of the organic
manures--especially of green manuring. Fertilizers, on sandy soils,
where they will not long be retained, should be applied only
immediately before planting, or as top and side dressing during growth.
Sandy soil in the garden will produce early and quick results, and is
especially adapted to melons, cucumbers, beans and a number of the
other garden vegetables.
GRAVELLY SOIL is generally less desirable than either of the others; it
has the bad qualities of sandy soil and not the good ones of clay,
besides being poorer in plant food. (Calcareous, or limestone pebble,
soils are an exception, but they are not widely encountered.) They are
not suited for garden work, as tillage harms rather than helps them.
THE IDEAL GARDEN SOIL is what is known as a "rich, sandy loam," at
least eight inches deep; if it is eighteen it will be better. It
contains the proper proportions of both sand and clay, and further has
been put into the best of mechanical condition by good tilth.
That last word brings us to a new and very important matter. "In good
tilth" is a condition of the soil difficult to describe, but a state
that the gardener comes soon to recognize. Ground, continually and
_properly cultivated_, comes soon to a degree of fineness and
lightness at once recognizable. Rain is immediately absorbed by it, and
does not stand upon the surface; it does not readily clog or pack down;
it is crumbly and easily worked; and until your garden is brought to
this condition you cannot attain the greatest success from your
efforts. I emphasized "properly cultivated." That means that the soil
must be kept well supplied with humus, or decomposed vegetable matter,
either by the application of sufficient quantities of organic manures,
or by green manuring, or by "resting under grass," which produces a
similar result from the amount of roots and stubble with which the soil
is filled when the sod is broken up. Only by this supply of humus can
the garden be kept in that light, friable, spongy condition which is
absolutely essential to luxuriant vegetable growth.
Previous: APPLYING MANURES
Next: PREPARING THE SOIL
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