Yorkville enquirer. [volume] (Yorkville, S.C.) 1855-2006, 1915-01-29
AVAILABILITY OF LIMESTONE
Experiments Show Results When
Ground Coarse or Fine.


One Of the most important questions
concerning the use Of ground lime
stone Is that of the proper degree Of
| writer's in the Middle West have as
| serted that II limestone is ground
finely enough so that the coarse par
| ticles are Of the size Of small peas, 1t
| will answer agricultural purposes. 1t
has also been intimated that such
limestone Is more economical than the
| finer product. This Is based upon the
slightly greater cost Of fine grinding.
and upon the idea that the coarse
material will insure the presence Of
| some carbonate Of lime in the soil for
considerable number of years after
| its application.
1t seems to be practically accepted
by all authorities on the subject Of
lime for agricultural purposes that 1t
Is only the very fine product which
can be Immediately useful. 1t Is also
we'll known that If enough finely
ground limestone Is added to a soil
to fully correct its conditions at the
outset. the effects Of such an ap-
plication endure for several sue
cessive years. 1t is also well recognized
that II too little finely pulverized
limestone Is used at the outset, there
shortage in the crop, even though
ample quantities Of fertilizers are en-
ployed. This loss in the first crops
may readily be sufficiently great to
pay many times over for the slight ad-
ditonal cost of finer grinding.
Some experiments have just been
conducted by Hartwell and Damon at
the Rhode Island Agricultural Exper-
iment station which shed strong
light upon this question. Land OF
very uniform character, but highly
deficient in carbonate Of lime was Sc
lected for the purpose. Liberal guam
titles Of the same kind Of complete
fertilizer were applied in like amounts
Quoted with mangels and with carrots.
The experiment with mangels in
1918 showed that for every 107 pounds
Of crop secured without the use Of
lime there were 1873 pounds, when all
the lime was fine enough to pass 10
mesh sieve. but was too coarse to
pass q 20-mesh sieve; whereas, when
all Of 1t was fine enough to pass
sieve having 80 meshes to the linear
inch, the yield amounted to 3S9
pounds. The following year l914
the yield of carrots without lime
amounted to It's pounds. The yield
were used amounted to 314 pounds,
and the yield where the lime was all
fine enough to pass an 80-mesh sieve
was 563 pounds.
In the former case the unsifted
limestone gave a yield of 279 pounds
of mangles. whereas the next year the
unsifted limestone gave yield OF 47O
pounds Of carrots. In this case the
unsifted limestone had been ground
so fine that all Of 1t would pass
through a sieve having 10 meshes to
the linear inch. The finest grade of
limestone, all Of which was capable Of
passing a sieve having 80 meshes to
the linear inch, was found to be
slightly more effective, considering the
total yield Of the two years, than the
same amount of lime in the form Of
slaked lime. These results indicate,
therefore that very coarsely ground
limestone, even If 1t Is all much finer
than has been mentioned on frequent
occasions In the Middle West, is far
less economical for general agricul-
tural purposes than that which is
more finely ground.
This point is particularly impressive
when one bears in mind that the un-
sifted ground limestone produces but
270 pounds Of mangels, whereas the
fine product produced 3S9 pounds. 1t
was found upon examination Of the
unsifted ground limestone that Sc per
cent Of it passed through sieve hav-
ing 80 meshes to the linear inch; 13
per cent, which was too coarse to pass
through an 80-mesh sieve, passed
40-mesh sieve: and IL per cent passed
through a 10-mesh seve, but was too
coarse to pass a 20-mesh sieve.
These results show conclusively
that II the limestone had been ground
so that all of 1t would pass 20 or 30
mesh sieve, its efficiency would have
been decidedly increased, and by the
additional grinding necessary to Sc
cure that degree Of fineness, the per-
centage which would have passed an
80-mesh sieve would have been still
greater than 1t was in this case. Ac-
tual tests in the field are the only true
basis for drawing conclusions as to
whether coarse or fine limestone
should be used. In this particular
case actual experiments support what
ought to be evident, and they are in
accord with the practical experience
as noted in progressive farmine COM
munities.-Dr. H. ]. Wheeler, former
ly Director of the Rhode Island Ex-
pertinent Station.