The farmer and mechanic. [volume] (Raleigh, N.C.) 1877-1885, 1878-04-04
To Retain Fertility IN Soil.
RY PEoF. Z. 7. cox.


fore Franklin County Pomona
Grange. at lis meeting IN Feb
ruarv:
The analysis Of samples Of soil
from a field viii not furnish =
guide to the wants of tile soil for
growing profitable crops. me
most essential mineral IN the soil
for agricultural plants is phosphorlc
acid. and the most productive soils
ONLY contain this substance Il small
quantities, tarying from 10 TO
6-1O of one per cent, a quantity,
50 small that il has only been pos
sible for chemists 10 determine is
presence by comparatively recent
improved methods Of analysis.
When estimated for an acre Of soll,
taking the depth TO be ten inches,
the amount of phosphoric acid
which arabic SOL contains may
range from five TO twelve tohs.
From this it will be seen how diff
cult it Will be to point out the ne
cessities Of the field from q mere
ANALYSIS of the soil.
Other matters must be taken INTO
consideration and will undertake,
as briefly as possible, to point them
out for the benefit OF your Society.
First: YOU must look to the ply
steal or mechanical condition Of
the soil to be cultivated. If 1t Is a
clavey soil and retains a quantity
Of water that is only removed by
the evaporation which goes on at
the surface, then to render 1t tit
for cultivation 1t must be under
drained. Second: if the land has
been under cultivation and the
crops have been removed and dis
posed Of, then the mineral constlt-
uents Of the plants that have been
removed must be returned TO the
soil IN anne manner. Plants are
0mpOsc | of organic and mineral
substances. If YOU burn the plant
ne organic matter IS consumed, or,
lore correctly speaking, volatll-
zed and sent back into the at
nosphcrc from whence it was de-
lived. The inorganic part, or MIN
eral matter, derived from the soil
remains as ash. Now, us the yola-
matter is derived from the atmos-
phere. we must turn our attention
to the ash constituents as being the
only substances taken from the
soil. The total amount of ash for
a given plant may yaryln quantity,
but no one Of the following sub
stances are ever absent from agri-
cultural plants, VIZ: Phosphorus,
potash, soda, lime. magnesia, iron,
sulphur, silica, and chlorine. More
than one-half of the ash constitu-
ents of the grain is made up Of
phosphate Of lime. A crop Of
twenty five bushels Of wheat ker-
nels and two tons of straw taken
from an acre of land Will remove
$50 pounds of mineral matter from
the soil: Of this amount of grain
will contain lG4 pounds Of phos-
phoric acid and the straw 81 pounds
the combined product Will remove
about 2G pounds of phosphoric
acid. The other mineral constitu-
ents of the ash, with the probable
exception Of potash, are present IN
sufficient quantity III the soil. Now,
from the small amount Of phosphor-
ic acid naturally existing IN the
best of soil, YOU may readily see
that constant cultivation and re-
moyal of the crop viii rapidly ex-
haust it Of this essential mineral
plant food, and the only remedy is
to return it to the soil. OF course
YOU will find these constituents in
barnyaId manure, but this VIII
only represent a part of the crop as
the greater portion has been taken
to market and sold as grain, beef
or pork; and while you should
save and use all the barn-yard ma
nure that can be had, the deticien-
cy must be made up IN some other
way, and the most economical way
IS to use mineral fertilizers. The
best mineral fertilizer is pure SUI
perphosphate Of lime, but owing
to the liability Of It's being adul-
terated | would recommend fine
bone dust, which Il mainly com
posed Of phosphate Of lime. This
may be had IN the market at all
times at about $50 per ton. One
hundred pounds Of bone dust con-
tam about y per cent. OF p~hospho-
ric acid. As the bone dust is not
readily soluble III water, the soil