PRESS BULLETIN No. 109. February 20, 1909.
FlorPda AgriCulrlual Experimenit $Iaon.
THE TREATMENT OF MUCK SOILS.
BY A. W. BLAIR.
Muck soils are formed by the decay, in low wet places, of grasses, weeds,
twigs, leaves, and even trees. Being so largely formed from vegetable mat-
ter, they are much richer in nitrogen than ordinary soils. They usually also
contain small amounts of phosphorus and potassium. No systematic survey
of the muck soils of Florida has yet been made, but such evidence as has
been accumulated tends to show that they are generally very acid or sour.
If muck soils are to be cultivated it is obvious that they must first be
drained. This is necessary in order that they may become the home of the
various kinds of micro-organisms that play an important part in the making
of a fertile soil. These micro-organisms need moisture, but they cannot de-
velop in mud or standing water.
Cultivation should be deep, especially at first, in order that the air may
thoroughly penetrate the soil. Muck soils often contain substances that are
injurious and even poisonous to plants. When these poisonous substances
are exposed to the air, they are probably oxidized to a considerable extent,
and thus destroyed. A free circulation of the air also improves the condi-
tions for the development of the useful micro-organisms.
Suitable materials for this purpose are finely ground limestone, air-
slacked lime, wood ashes, and marl. A fuller discussion of this subject is
found in Bulletin 93.
It will be necessary in most places to use larger quantities on muck
soils than on upland soils. If limestone is used, two
should be applied. If lime is ta
used. The material should be
months before the crop is pla
neutralize the acid.
The importance of destr
we remember that the micr rm.b nvert organic nitrogen into a
form that can be used by plants cannot develop in a highly acid soil. The
limestone and lime also furnish a suitable base with which the nitric acid
that is formed may unite, thus producing calcium nitrate which can be taken
up by plants.
If muck is to be used on upland soils, it is also necessary for the acids
to be destroyed. This can be done either by composting it with one of the
materials already mentioned, or by applying the latter when the muck is
applied, or afterwards, and thoroughly mixing both with the soil by cultiva-
tion. Muck may be improved by simply drying and thoroughly airing it.
This is especially true of mucks that contain iron compounds. We cannot
expect a satisfactory yield of such crops aS celery and lettuce on muck land
until the acids have been largely destroyed.
It occasionally happens that a muck deposit is underlaid .with marl, or
is in close proximity to a limestone formation. In such cases it is not so
likely to be acid, and might not require the treatment with lime.
Muck soils being especially rich in nitrogen should, one would think.
require but little, if any, of the nitrogenous fertilizers. Experience, however,
has shown that in many cases they do require added nitrogen. This is be-
cause they are so strongly impregnated with acids that the bacteria which
would otherwise convert the inert nitrogen of the organic matter into soluble
nitrates, cannot live. When this unfavorable condition has been corrected, less
nitrogen in the form of commercial fertilizer will be required. If a quick-
growing vegetable crop is being produced, nitrate of soda may be used to
good advantage, as may also stable manure since it introduces beneficial
bacteria; but sulphate of ammonia, and organic forms of nitrogen (such as
cottonseed meal and castor pomace) should not be used; the former because
it will aggravate the acid condition, and the latter because there is already
enough organic nitrogen present. Phosphoric acid and potash may be used
liberally if desired. For phosphoric acid, ground bone is an excellent ma-
terial; while a ton or two of finely ground phosphate rock (floats) would
also be helpful; not so much, however, for immediate results, as for future
crops, since the acids in the m-uck will very gradually convert the insoluble
phosphoric acid into the available form. For potash, any of the potash salts
will suit. Kainit has been used i k soils of Illinois, with good re-
suits. Hardwood ashes are an ifthey can be
produced on the place or bought
State papers please copy.