Evening star., 1898-10-29
S0ILSOF THESTATES
Important Experiment Going on at
Agricultural Department.
COMPARATIVE rESf7OFss PRODUCTION
Districts Earth Needs Scientific
Treatment to Be Very Fertile.
N TRIO IDS PART

There is a little frame and glass building
just back of the Agricultural Department
in which an. Interesting and lmportant
experiment Is going on, to show the COM
parativs productive values Of soils. or
earth. gathered from all over the United
States.
Looking through the glass sides there
can be seen lows of white pots, like large
flower pots, extending across the interior
and resting on trucks fitting upon tracks,
which continue thirty or forty feet to the
west outside the structure. These are filed
with earth almost to the top, and each not
has number of Its own. The contents
range in color from the light yellow Of
sandy to the black Of rich swampy soil.
At glance, the interior looks like an
ordinary plant propagatins house, but as
matter of fact, 1t Is the scene of one Of
the most deeply scientific and progressive
of the many Investigations now being con-
Quoted by the institution under Secretary
Wilson.
In the 173 pots are samples of earth from
fifteen states and the District Of Columbia
These are California, Florida, Illinois, In
diana. Iowa, Kansas, Maryland, Michigan,
Missouri. Montana, New York Oregon,
Pennsylvania, South Dakota and Wiscon-
sin. The other states will be investigated
in turn later, although the present collec-
ton includes about every type now culti-
waited in the Unitel States, and represents
a. wide variation as to character ana
nature. The experiment was begun five
years ago and will be completed next
year. Therefore it Is not possible now to
present the final conclusions derived from
the carefully observed and recorded phe-
nomena.
The First Effort.
The experiment Is the first effort to
reach definite results with particular soils,
and the method used Is based upon COM
pairing many growths Of the same crops
upon soils of great variety of character
and composition. The crop and the manner
of its cultivation remain always the same
the soils OILY differing. The results there
fore are expected to show the differences
in vegetation, due to the differences IN
soils. The great practical utility derived
Is in the farmer being able to discover.
even in a small measure, the preference of
any particular vegetation for any one soil
or class Of soils.
From each state named with grea. care
was collected a sample of each of four of
it's Soils the virgin surface earth, found in
sections never cultivated such as the
prairie lands of the west, the virgin SUBJ
soil, taken from the same parts. but dug
from below a foot in distance from the sur
face; cultivated surface soil and cultivated
subsoil. These were afr dried, sacked,
labeled and forwarded from the agricul-
tural stations in the states and arriving
here were quickly air dried again and small
samples of each were taken for chemical
and physical examination. The remain
ing soil was placed in the pots. which are
constructed that the water supply IS
carried upward through the earth from a
reservoir surrounding the pot at its mid
die, not poured on the top, as usual with
flower pots. In this manner the top of the
soil is kept loose and dpeng not hard and
Eaked as happens with flower pots water
ed from the surfacs.
Objects of Analysis.
The chemical analysis Of the samples was
for the purpose of r.sh owing the constitu-
ents OF each soil in the way of potash
phosphoric acid and nitrogen, the principal
elements that sustain plant life; although
sand, lime, magnesia and a dozen others
to be found. The physical analysis was
FOR the purpose of separating the soil of a
sample into standard sizes and also to as
certain the capacity of each kind for alb
sorbing and holding moisture. record
Of each result is carefully made and pre-
served in order to compare 1t with the re-
analysis of the soil at the end of the six
year arbitrary period next year.
The plants selected for the experiments
were oats. beans and buckwheat These
show very plainly the vitality and COM
parative productive quality of the SAM
pies. Oats belong to the cereal family,
which Is easily grown. but does not add
nitrogen to the soil Beans belong to the
leguminous variety, which absorbs nitro
gen and fertiliZes the earth. The buck
wheat was chosen because two crops of il
can be taken every year.
Soil Is enriched with nitrogen either by
direct deposit from the atmosphere or
through leguminous plants, whose roots
are the homes of an organism bacteria
which feeds upon the nitrogen and excretes
it in the form Of nitric acid. Earth may
be rich in pure nitrogen, but plants can
absorb it only as nitric acid. These organ
isms are in the soil either naturally or by
inOcula alton.
AS an Illustration of the latter method,
land was found full Of nitrogen, but which
would not sustain plant life. Organism
bacteria, forming in size a mass about the
size of a small marble were placed in the
ground, and as they multiply very rapidly
soon the nitrogen was converted into nitric
acid and plant life rendered possible.
Attempts to graft or place the bacteria
on roots of cereals have failed, conclusive
ly showing that cereals do not Of them
selves add nitrogen or strength to the soil,
but In fact, draw from the supply in store
without compensating.
Mode of Operating.
After filling the pots, the seed is evenly
laid over the soil and covered to the prop
er depth, The soil Is then saturated with
water from the reservoirs in the pots, and
termination begins. the trucks laden with
pots being run into the outer air during
sunshiny days and placed under cover In
rain or at night. The plants are watered
daily or as often may be necessary.
during growth, In such a way as to keep
always a suf11cient supply of moisture for
the use or the growing shoots. Distilled
water Is used. so as to prevent the addi-
ton OF foreign or ferti'izing matters to the
soil. careful record is kept of the quan-
tity or water added to each pot. in order
to show how much rainfall each year.
would be necessary or should be had tc
produce development or crop equal to
the one obtained under the artificial or
experimental conditions
periodical notes are made regarding prog
ress or vegetation. height, strength and
color. At or near matfrity the pots are
transferred to Photographic studio on the
grounds, grouped accordisaes to the soil and
crop, and photographed.1 Thus record of
vegetation In the pots is secured which
may De used in comparing the growths in
the various pots and in illustrating any
pecu1arity of soil as shown by the vegeta-
non the plants then are carefully harvest
analyzed to ascertain ths amounts of nlant
1000 or nitrogen, potash ,and phosphoric