The Wilmington morning star., 1942-08-31
CARDWELL URGES
lime use IN S. {.
Soil Acidity Is Shackle On
Agriculture; Yield
Increase Needed
Guy A. Cardwe1l
General Agricultural Agent
Atlantic Coast Line Railroad

Company
For increased profit opportuni-
ties and war purposes, it is OF
Importance, particularly at this
time, that farmers increase yields
of most crops In this connection,
they are told tow to do this in a
very recent Clemson Agricultural
college publication, Circuar 2l8,
July 1912. from which I am brelt-
ly quoting:
Soil acidity is shackle on South
Carolina agriculture, making 1t
almost impossible to develop a
system of diversified or livestock
farming, preventing the atisfac-
tory growth of soil-building crops,
and reducing average yields OF
pastures, general crops, and truck
crops.
Over 80 percent of the cropland
and pastures in South Carolina is
too acid to grow legumes and le-
gume and grass mixture success
fully, and because we are using in
sfficient lime materials, our soils
are becoming more acid every
year. In order to correct this grow
ing acidity, it would be necessary
for farmers to use approximately
/, 100000 tons of limestone annual
1y. Our present annual use of lime
material is only about 10 percent
O: tn tonnage needed. If South
Carolina agriculture is to prosper,
there must be substantial in
crease in the lime tonnage used
annually.
Generally speaking, farmers have
been slow to inc1ued difinte linn
ing program in their farming ope-
rations. This attitude is due to
several reasons: Cd Immediate
results cannot be observed, (2)
functions and value of lime are not
fully understood, 90 inadequate
facilities for hauling and spread
ing, (4 dependence on commercial
fertilizers alone, (5) inability to
finance a lining program.
A lining program will not solve
all problems. but lining is the
first step that is essential to con-
tinued profitable farming. Lime is
the key to diversification.
South Carolina soils are very de-
ficient in phospates, and available
phosphates for crop use are vitality
affected by soil reaction. Phos-
pilates are most available between
phi SIS and ph rs, while above or
below this range they are partly
fixed by other materials in the
soil, and ere less available for
plant use. The poor growth which
plants often make on very acid
soils may be due as much to phos-
phate starvation as to any other
cause. Lime and phosphate go hand
in hand.
On some of our very acid soils
it is often necessary to apply re-
latively large amouts of lime, which
sometimes causes potassium to
become less, available. However,
such conditions can be easily cor
rected by applying potash ferti-
Izers.
Calcium, magnesium. and potas-
SUM are the principal basic ele-
ments are found to certain ex-
tent even in acid soils, otherwise
plants would not be able to grow
in soil below ph 10. Calcium is
the chief element of importance in
lime materials, and is aften refer
red to as lime. The quantity of cal
cium available for crop use in
creases sharply with increases in
ph. The relative availability of
magnesium is similar to that of
calcium. Sand drown of tobac-
CO, "red dust" of cotton, - streak
ing in the leaves of corn, and the
lack of normal color in other plants
are somtimes evidence of insuffi-
cient available magnesium. Such
troubles ordinarily occur in very
acid sandy soils. A few crops,
such as watermelons and strawber-