Bristol news. [volume] (Bristol, Va. & Tenn.) 1867-189?, 1868-11-27
8ieIS ami Sarhem.
The Action Of Plaster and Lime.


No matter how much lime is applied,
our farmers continue TO Gud benefit 20
their grass lands from plaster (sulphate
of lime). SO small Quantity as one
bushel to bushel and half to the
acre, often shows very marked results,
and the two crops which seem to be
most benefited are clover aud corn.--
Where sprinkle Of plaster has been
applied to the hill of corn, the benefit
is sometimes, though not always, OBJ
servable in the subsequent increased
luxuriance Of oats, wheat, aud even
grass, indicating exactly where the bill
had stood
The action Of plaster is not so we'll
understood by farmers or chemists as
that of lime. Some Seasons no effect is
observable at all, and this is especially
found to be the case in very dry ones
1t is usually sowed broadcast, over pas.
ure fields ia the spriug of the year. by
hand Some farmers only use it on
their clover fields, but others SOW it on
all their grass fields, and do this regu-
1arly, whether immediate benefit fol-
lows or not. A. common saying being,
as with lime, "Mut tie main thing is 10
get At on "
From the fact that where the land
has been strongly lined, so suiall a
quantity as bushcl to the acre of plas-
ter often shows decided benefit there
would seem great plausibility in Liebig
cheory, that its effects must be traccabe
not to the lime, but to the sulphuric
acid This is also further confirmed
from its being found most beneficial
when there is a rainy season, the amo-
MIA in rain water in tie form of carbOn-
ate volatile salD is decomposed, the
sulphuric acid having greater affinity
for it, thus forming two new compounds,
sulphate of amonia aud carbonate of
lime, Liebig says, "that as arabic soil
has also the property as absorbing am-
mouia from the air and rain water, and
fixing it in the same or even higher de-
gree than lime, there is only the sulphu-
rio acid left to look for an explanation
Of the favorable action of gypsum upon
che growth of clover" He says, "thc
action of gypsum is often puszling,
and gives the following extraordinary
results, without venturing to draw any
definite conclusions from them. We
copy his own words
II found that solution of gypsum
in contact with all the arabic soils which
/ used; underwent decomposition, part
for the lime separating from the suiphu'
rio acid, and magnesia aud potash ia
king its place, quite contrary to the or
binary affnities.
This experiment shows that the sc'
ton of gypsum is very complex, and
shat it promotes the distribution of both
inagnesia and pntash in the ground, ex
ercisiug a chemical action upon the sol
which extends to any depth of it, anC
that in consequence of the chemical anc
mechanical modification of the earth
particles of certain nutritive elements
become accessible to and available fol
the clover plant which were not SO be
fore"
If Liebig's views arc correct, tn,
practical experience we would draw is
that it would appear much better for GU
farmers to change their system, aud ap
ply pla ster in the fall instead of spring
the rains aud SHOWS through the fal
and winter being certain to supply th
required amouia for combination with
the sulphuric acid Of the plaster. l
would seem the province of the chem
ist to investigate causes, and elucidat
scientific principles, and for the furme
to make practical applications and de
ductions.-Procticai Farmer.