The progressive farmer. [volume] (Winston, N.C.) 1886-1904, 1898-05-10

4 ~SSS@SA
manure in that they are instrumental
in decomposing the insoluble mineral
compounds with the result Of making
potash and phosphoric acid more avail
able. Their action in this way, how
ever, is only secondary and Of minor
Importance.
The leading art 'cles used to improve
the physical condition of soils are barn
yard manure and other coarse residues
OF plants (such as straw, coWpeas,
clover and green crops ploWed under
for manure). lime and ashes. OF these
barnyard manure and other material
of its class, improves the water, holding
power of sandy soils because of their
property Of holding large quantities Of
water in themselves in much the same
way that sponge absorbs and holds
water. Thoroughly mixed with clay
soil they assist in making it more por
GUS and open. It thus becomes more
permeable TO air, less retentive of water
and less liable to cake on drying.
Vegetable matter has also warming
influence on soils. Because Of its dark
color it makes them absorb heat more
readily and by assisting the escape of
water in clay soils reduces the cooling
effect Of the very large amount Of
evaporation which otherwise takes
place. The purpose Of barnyard ma
nure and litter in improving the phys
ical condition of soils will be best served
by applying that which is we'll rotted
to sandy soils and that which is coarse
and strawy to clay lands.
Lime and ashes also make sandy
soils more compact and clay soils more
porous.
Commercial fertilizers are usually
used for the sole purpose of supplying
food to the soil to be used by growing
plants. Except in the case of kainit,
which contains much gypsum, none Of
the commercial fertilizers used for inn
proving the mechanical texture of the
soil nor to liberate plant food already
in the soil in an unavailable form. The
only elements that are considered OF
any consequence in commercial fertili
zers are nitrogen, phosphoric acid and
potash. And these elements must be
in soluble form or they may remain
in the soil for years before being f1t
for use. For instance, horn Ind leather
are rich in nitrogen, but it requires
many years of decay to fit them for
plant food. Lime and plaster are
usually Improbable as manure when
they cost more than $6 or 81 per ton.
Soils differ widely in fertility. Many
soils are abundantly supplied with all
three of the prime elements, nitrogen,
phosphoric acid and potash and many
are deficient in all three, while some
are deficient in only one or two.
Different crops have different needs.
On the same soil some kinds will be
especially benefited by nitrogen, son g
by phosphoric acid and some by pot
ash. Cowpeas and clover will receive
little or no benefit from nitrogen, but
they may on some soils be greatly
bene flied by phosphoric acid and
especially potash. Wheat and oats
are believed to be especially benefited
by nitrogen, potatoes and tobacco by
potash and turnips by phosphoric acid.
especially phosphoric acid soluble in
water.
The best index as to the nitrogen con
tents of soils is the amount of humus
or decaying vegetable matter which
they contain. This is the material
which will be burned from dry soil
when it is placed on hot stove. 1t is
the material which is being continually
burned from the soil by natural
agencies. The conditions for the work
ing these agencies are greatly improved
in cultivated soils and the result is that
such soils coon become deficient in
humus, and consequently in nitrogen,
It is largely due to this loss Of humue
that soils which were fairly fertile
when first broken from woodland
} soon become sterile and barren un
der careless and unwise manage
ment. An examination of such soils
will show that the former dark color
of the first few inches has disappeared.
The original supply of nitrogen has
become exhausted. The element OF
fertility in which the majority Of soils
! are deficient is nitrogen. The eye
readily detects the absence of humue
in the cultivated soils OF all sections
To keep the soil well supplied with
humus requires constant and system
, attic effort on the part of the farmer. II
maybe done by growing clover and
coWpeas, by returning to the soil such
straw, stable manure and litter as the