Atlanta tri-weekly journal. [volume] (Atlanta, Ga.) 1920-19??, 1924-12-04
Applying Crushed Limestone to
Alfalfa

Applying Crushed Limestone to
Alfalfa
w. d. A, Macon, Ga, writes:
[ have put on my alfalfa in two
applications between four and
five tons Of limestone rock per
acre. The material is guaran-
teed to contain 1872 per cent of
carbonates. Is magnesium car
Donate as effective for the Dur-
pose in question as calcium car
Donate?
For a long time it was believed
that dOlOmitic limestones could not
be used with satisfaction in Georgia.
DolOmitic limestones, as YOU doubt
less understand, contain about equal
proportions of calcium carbonate
and magnesium carbonate. The lat
ter was supposed to exercise a toxic
effect on plant life. Later. a more
complete investigation, however, has
proven this claim TO be an erroneous
one 1t is now recognized by scien-
lists that 81 pounds of magnesium
carbonate will neutralize as much
acid as 100 pounds of calcium car.
Donate.
There is no particular objection.
therefore, against your using the ma
terlaI described in your letter on the
oasis indicated and for the purpose
you have in view. In fact, we have
used limestone under alfalfa here at
the college farm and secured Just as
good and satisfactory results as were
obtained from application of ground
limestone obtained from localities
where the percentage of calcium car
Donate in the native rock ran as high
as SO per cent. The ANALYSIS YOU
quote shows that the rock in oues-
ton contains "a per cent of carbon
ates, 50 per cent of which is in the
form OF magnesium carbonate.
Merits of Magnesium Carbonate
q. j. y, Atlanta, Ga, writes:
Does magnesium carbonate act
IKE calcium carbonate in sweet
ening soil? Would I be war.
ranted in using a material an
alyzlnS 90 per cent calcium and
% per cent magnesium? Fo,
clay soils TO be covered with
woods earth, how many tons per
acre Of calcium carbonate do
' need to make a high-class lawn
and garden soil?
ordinarily, limestone is made I'm
chlefly ct what is chemically known
SHOWN that it would take at leasf
hmestones contain both calcium, car.
donate and magnesium carhoneto
IheSe materials are often found in
rock OF this character in about eouaI
proportions. For a long time if was
thought that magnesium carbonate
eHeFled toxic or injurious effect
on pants growing in the soil Tbts
was apprehension. however fo,.
1aIeF and. extended studies have
shown that it woul dtake at 1nost
~ tons per acre to exercise ap,-
Il,aterla! effect upon plant life.
HiS I'9Iour pounds of magnesium,
carbonate will neutralize as much
dc4o as 100 pounds of calcium ca~.
cohate. You will see, therefore I'M.
magnesium carbonate exerts = sro,t.
OF SWeetenlng effect in the soil t5.,,
caIclum carbonate. Thus. there an.
pears 10 be no scientific Or nractic,r
grounds on which to base a dafini+e
objection to the use Of doIor5ifi.
limestone. In your situation tbara-
4oFe, we would not hesitate RI nc.
the material in question.
anywhere from five to ter tons %
woods earth should be applied 10 a
Gay SOIL for the purpose of ara1io'
1ati.lS or improving the filth of Tho
u ace thereof. \ ton Of caloiI,,,7
c.'!ponate or dolOmitic Iin7eefo,o
Shouia originate from birh.~r9Lo
IoeN' Personally. We Womb ern1,,
this calcium Carbonate ana ~. -