The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1895-02-01


e1- out perhaps more upon 81. :, 49,. -,
IN which they occur. sr,ss -. -
TAN IN abundance ali the esanas,,s -
fertility and ssiIl be barren. T-ns- /. -
cause the tnlateriaI required ~ ~.
pant must be IN Solution tw.fs,ys = -,
DC assimilafed, and. aifhcr,yh r-as<v,.
80. - aiace. It may De in al insosrfae
~.. =. sucn q case an application OF
- LINERS viii be just as essential to
luctIveness az In case OF a soil
"iioisy destitute of mineral plant food.
Tne mineral substances that are pres
ens in varying proportions IN all soils
are silica, IRON. ailxnina, lire, nsagnessa,
soda, potash. phosphoric acid, suiphusic
acid, chioriu and some. times man
games and fiuorine. In order 20 better
understand the following arzsyfical
results. some Of the chief Character
istics OF these substances are given be-
low.
Silica Is compound of the elements
SILICON and Oxygen. IT not only forms
the basis OF most soils. but Is the most
abundant solid material OF the earth
The quartz crystal Is pure silica. Sand
and clay are largely composed OF 1t. 1t
- present In soils In greatly varying
proportions. sandy coils having from 20
70 70. Per cent. while lime soils and
mari contain as low as 20 TO 30 per
cent It occurs mostly in an fnsoluble
condition, In which state its action -
merely mechanical. Most fertile soils
contain some OF Il IN a soluble form
and then 1t becomes q source OF plasn
food
Iron. in the form Of nnely dlfYused
ferric hydrate. Is a constituent of all
soils. Its percentage varies from / I-2
10 20 per cent. and often gives the color
to red soils. Yet it frequently happens
that soil distinctly red IN color con-
tains less iron than one that has
much darker color. This is well illus
trated by samples Nos. and TO- given
In the following pages. No is dark
colored sol. while No. 10 is q sample
OF the characteristic red soil Of West
ern Washington. but they contain
equal amounts OF ferric hydrate. The
color apparently depends more on the
mode OF distribution than on the guam
THY. As a rule. soils rich In iron are
poor inorganic matter. although their
fertility is very great. The beneficial
effects OF iron are largely me-
chanical, increasing the power OF
the soil to absorb and retain
heat and moisture and rendering tillage
easier in clay lands The green color
OF plants Is due TO the presence OF iron
IN the sod, and undoubtedly other Of
its beneficial effects are due to chemi-
cal causes: but this latter point Is as
yet somewhat obscure. Soils having
slight color contain from IL 10 4 per
cent. ordinary loans from 4 to z per
cent. red lands from TO 12 and occas-
ionally as high as 20 per cent.
lAiumfna combined with silica forms
pure clay. The clays in soils have
usually q reddish color. due TO the
oxide OF iron they contain Alumana
does not directly contribute to the
growth OF plants: it Is seldom absorbed
by their roots and therefore is not d.
rect food for them. In the form of clay.
however. 1t is a. most essential consti-
tuent OF the soil. Clay. as well as
humus and ferric hydrate, is very re-
tentive OF water, and has the power of
absorbing and retaining the easily
soluble compounds supplied by manure
and other fertilizers. This property of
clay prevents these fertHizing subtances
from being washed out OF reach OF the
roots OF plants by the first heavy rain.
Clay is derived mainly from the de-
composition of rocks containing field
spar. and hence IS frequently associated
with a considerable supply of potash.
The alumina ranges from l TO per
cent. In sandy soils to 10 per cent.
In clay soils.
Lime In regard to the presence of
lime In soils. Prof. Hilgard says:
.Other things being equal. the thrift
ness OF a soil is measurahly dependent
upon a certain minimum percentage
lime" As the results o feritca no a ndc
lime AS the results ola certain def
mite amount of lime In a sol. the fol-
,owfng points are found true:
% A more rapid transformation OF
vegetable matter into humus.
(2) The retention OF humus against
the oxidizing effects of hot climates.
go Whether through the medium OF
this aumus, or in a more direct man
Ter. il renders adequate for profitable
culture percentages of rhosphoric acid
and potash so well that in case of
deficiency of lime or its absence the soil
would be practically sterile.
tenance OF the conditions o. nitrfica-
ton, whereby the inert nitrogen OF
the soil Is rendered available.
This controlling influence of lime
renders it's determination alone a mat
ter OF no small interest. since Its def
cheney can very generally be cheaply
rernedled. Lime is among the most
variable of soil constituents. existing
In all proportions from mere tracts
10 80 per cent IN limestone soils. 1t
r. usually found In the form Of calcium
carbonate Glmestone). calcium stiiphase
fgypsun) or calcium phosphate. Gyp-
sum is somewhat soluble in pure water,
and the carbonate and phosphate are
soluble in rain water by virtue OF the
rarbonic acid Il containg. Hence, all
three OF these forms are capable OF
furnishing the lime 80 necessary for
vigorous plant development. II is OF
unusual Importance as n soil constit-
uen;. inasnnch as II is not only n nee
cessary ingredient OF plants. but II
cxerts A peculiarly beneficial effect on
the physical properties 81 the soil.
Magneeia. This substance resembles
nuse in many of tts pgopegyies. and is
generally found accompanying IL In
rocks especially in doinsnite. or mag
neslan limestone. EPSON salts Is a CON-
r,,,f,,a or ma gnesia with susphursc acid.
NarreSia lis Lrund. In ali cultivated
ss,sls and seems 10 I've essential 10 the
healthy development Of many plants.
rs.,.~~S - s,,t,rh .Ax-t.ianrs that a ssssys;s1y