McNairy County independent. (Selmer, McNairy County, Tenn.) 1902-1969, 1914-10-23
LIMESTONE FOR
TENNESSEE SOILS
Areas In State Where D0I0-
mite Is Abundant and
Easily Obtained
The NEED IS CLEARLY SHOWN
Crushed Dolomitic Limestone 10 a
By-product of Extensive Mining
Operations In STANDARDIZATION
Recently Made at Tennessee Station.

The need OF lime for Tennessee soils
has been clearly shown in Tennessee
Station Bulletin 81. Although most
of, our soils are deficient in lime, the
valleys of Tennessee are underlaid
with rich deposits of lime rock, and Of
dolomitic lime rock, the latter being
limestone carrying large percentages
of magnesium carbonate.
Crushed dolomitic limestone is q by
product of extensive. mining opera
tons in this state, and the magnetism
lime rock can, therefore, be obtained
very cheaply. Furthermore, there are
areas in this state where dolomite is
abundant and easily obtained for home
crushing, while limestone is either
scare or absent. For these reasons
the question of relative values of the
two limestones is one of great i'm
portance to the farmers of this state.
While the usual run of dolomitic
limestones analyze less in total car.
Donates than most of our limestones,
the greater efficiency of magnesium
carbonate in neutralizing soil acid
ity" gives our average dolomitic
limestone value cores onding to 100
pounds of limestone for each so pounds
of dolomitic limestone In other words,
our average dolomitic limestone Is
more efficient in the extent of its neu-
tralization Of soil "acldity" than equiv.
alent amounts of our average lime
stone.
Certain Investigations In this and
in foreign countries have shown that
a large excess of magnesia over lime
in the soil is not beneficial to plant
growth, and for this reason the ques.
ton of the ACCESSIBILITY of the use of
dolomite for some soils has been a
debatable one Recent investigations
at the Tennessee Station have shown,
however, that due to the foMdness of
the magnesia Of dolomite for solic-
ious substances in the soil, magnesium
carbonate, unlike calcium carbonate.
can not remain in the soil, but Is de-
composed. The substance formed
from magnesium carbonate soil treat.
ment is much less soluble than the
original dolonite and can not, there
fore, be so readily obtained by plants.
Eynarir, tc hau
dolomite is applied the calcium car
Donate is subjected to teaching in ap.
preciable amounts, whereas the mag.
nesia after conversion to insoluble
forms is largely conserved. 1t would
take a long period of the continued
use Of dolomite in the amounts or
dinarily used to effect this accumula-
ton OF magnesia in large excess over
lime, and this station, therefore, sees
no reason why dolomite should not be
recommended for agricultural uses
when applied as ground stone as we'll
as limestone, when applied in amounts
not exceeding four or five tons per
acre. The megnesian limestone is not
well adapted to burning, and it should
not be aapplied as burnt material In
ordinary cases.
BY utilization Of the cheap mag.
nesian lime rock by-product, present
land values could be materially and
economically increased by the use of
dolomite to established conditions
which would permit better growth OF
leguminous crops. Moreover, In later
years, after the soil has been built up
and crop production increased, any
further limestone required could be
done with pure limestone, the cost OF
which will probably be less and more
easily borne by farmers Who may have
benefited financially from the original
modest outlay for dolomitic treat.
ments. 1t would be well, however, for
farmers to receive individual advice
from their station as to the practice
most advantageous for their separate
needs.-W. M. MacIntire, Tennessee
Experiment Station.