Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1882-07-08
AGRICULTURAL PAPERS.
a SERIES PREPARED ESPECIALLY FOR
THE "REcoRD-UEIoN."
Presenting Instruction Contained In Lect-
ures from the Chair Of Agricult-
ure, State University.
[rwExrY.sIxrH AND LAST PAPER I

dlfncult LC cause IL 10 COUlDlHe With ObHeI
elements or compounds. 1t was therefore
concluded that the nitrogen needed ard
secured by crops was obtained from nitro
genous compounds, and not directly from
the free nitrogen of the air. The COM
pounds which furnish the most, il not all
of the hydrogen needed by crops, are am
monia and nitric acid. heterogeneous
manures are the most expensive and unre-
liable Of all the artificial fertilizers which
we have to buy. They are the first or Sec
ond TO be exhausted in most soil, and
especially in intense culture must be re-
newed each year If it is desired to secure
the maximum yield. The forms in which
they appear on the market are owingto the
fact that not only must nitrogen be pres
ent, but It must also be present in an avail
able form-not always worth as much to
the farmer as is represented by the money
value of the nitrogen which may be eI-
tracted from them by treatment with strong
chemical reagents. Horn, hair and leather
areI ii
As can be seen by the fumes which are
given off when they are burned but we
all know that they may be in soil for
year or more and often not suffer the slight
est decomposition. These three substances
often form the bulk Of the heterogeneous
matter OF many so.called "a heterogeneous
fertilizers" which are, on the strength of
certificate purchased from some unrelia-
BILE chemist, sold as containing a certain
per cent. of nitrogen-which they may
really have-the largest part OF which is
generally locked up in some unavailable
form, and is as useless to the farmer as so
much charcoal or sole.leather would be.
The principal source of nitrogen for agri-
cultural purposes is the guano OF the isles
of the Pacific Ocean. Besides nitrogen,
the gusro contains considerable amount
OF phosphoric acid and other nutritive
plant food. 1t is only by the unrestricted
that England and other European
countries have been enabled to sup
port their population. This has
been the case in every thickly settled
civilized country, except perhaps in Japan
and China, and there is not shadow of
doubt but that we of California must in
the near future resort to more rational
practices Of agriculture than most of US
make use OF at the present time. In the
Eastern States the Importance of the SUBJ
ject has already been realized and farming
is carried on with an end to the perpetual
maintenaI ce Of the fertility of the soil.
In all cultivated soil, and especially where
so much grain is annually carried from the
soil as is done in California, the first of the
principal necessary soil Ingredients to be
exhausted ia phosphoric acid. Next to this
comes nitrogen and last of the three is
potash. The effect of heterogeneous manures,
it will be remembered, ia to increase the
vigor OF growth of plants, and to increase
the mass Of the foliage. 1t is, therefore,
particularly needful to have an easily avail
able supply of nitrogen for all shallow.
rooted and quickly maturing crops.
DEEP-RooTED CROPS
Have much greater capacity for securing
pIant.food, and will often flourish on weak
soils whose per cent. OF phosphoric acid,
nitrogen and potash is too small to suffice
for crop OF one of the cereals. We see,
therefore, that owing to the cost and IN
certainty of commercial heterogeneous fer.
tilisers, and to the importance of having
an adequate supply of available nitrogen
present in all soils, it IS of the first i'm.
portance that all should thoroughly under
stand the available natural sources of
nitrogen, as well as the conditions which
best conduce to its appropriation and as
similation. Ammonia is very soluble in
water, therefore the rains which fall IN the
spring and fall must bring to the earth all
of the free ammonia of the atmosphere.
In speaking of ammonia in a previous
paper we mentioned the fact that the first
rains after the dry season always brought
down comparatively large quantities of
ammonia while after the atmosphere had
been washed by heavy rain, the rain
water is found to be almost free from am
monia. Ammonia exists in the soil In
three forms ~ Gaseous-the carbonate
~ physically condensed in the porous mat.
ter of the soil 81 in chemical combipa-
ton with other bodies. ~ From the fact
that the soil is at all times more or less
saturated with carbonic acid, which has a
strong tendency to combine with ammonia,
it would seem that the larger part OF the
free ammonia entering the soil would be at
once converted by contact with the car
bonic acid into the carbonate. AS we
have already seen, this carbonate is a
volatile salt, and therefore it exists in the
gaseous state on the surface soil at ordinary
temperatures. From this property OF
THE CARBONATE OF AMMONIA
1t is readily seen that, although large
quantities OF it may be formed, yet it
could hardly be expected that it would be
retained for any length of time in the soil.
And this is really the case. Unless the
soil contains come salt, as gypsum, which
readily unites with the carbonate of am
monia with the formation of a stable salt
of ammonia, We often lose large quantities
of nitrogen from our soil by the simple
volatilization and escape into the atmos.
Iphere of the carbonate of ammonia. ~
Although almost any soil and many other
bodies possess the power of absorbing many
times their own bulk of ammonia gas, yet
She amount of free ammonia retained in
soils is comparatively small. This is largely
owing to the facts that porous bodies satu-
rated with ammonia lose the greater part
of it when brought in contract with other
gases-for soils generally contain consider
able moisture which to certain extent alb
stracts the ammonia from the pores of the
soil-and that the soil contains many sub
stances which combine chemically with
ammonia. Clay exerts the strongest affinity
for ammonia in the presence of other gases
than does any OF the other principal soil in
gradients. We see, therefore, that
THE AMOUNT OF AMMONIA
Or ammonia carbonate vapor in a soil is
constantly varying, and influenced by the
rain, dew, evaporation, etc., as well as by
local causes. The actual quantity present
is generally small and hard to calculate accu-
rately. (3.) Ammonia unites chemically,
and to form more or less stable salts with
the acids of the humus group, with some
phosphates and silicates, and as double
salts with the humus acids and lime, mag
nesia, oxide Of iron, etc. 1t is through the
formation OF these salts that the ammonia