LIBRARY OF THE
UNIVERSITY OF ILLINOIS
AT URBANA-CHAMPAIGN
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CHECK FOR UNBOUND
CIRCULATING COPY
UNIVERSITY OF ILLINOIS
Agricultural Experiment Station
BULLETIN No. :«7
A FIELD TEST FOR AVAILABLE
PHOSPHORUS IN SOILS
BY R. II. BKAY
URBANA, ILLINOIS, AI'(,r>T. 1929
CONTENTS
PAGE
DEVELOPMENT OF THE COLORIMETRIC METHOD OF TESTING
SOILS FOR PHOSPHORUS 591
THE ILLINOIS ADAPTATION OF THE COLORIMETRIC TEST 593
The Reagents Used 593
Making the Test 593
Applying the Test in the Field 595
RESULTS OF THE TEST ON THE ILLINOIS SOIL EXPERIMENT
FIELDS 595
Results on Dark-Colored Soils 596
Results on Light-Colored Soils 598
Effect of Soil Treatments on Available Phosphorus 600
Available Phosphorus Found at Various Depths 601
SUMMARY AND CONCLUSIONS 601
LITERATURE CITED. . . 602
A FIELD TFS I FOR AVAILABLE
PHOSPHORUS IN SOILS
1U" R. 11. HUAY, First Assistant in Soil Survey An:ily>is
It is well known that many of the soils: of the Middle \Yest are
deficient in the phosphorus available for crop growth. After soil acidity
has been corrected and a proper rotation has been established, phos-
phorous frequently remains a limiting factor in crop production. Re-
-ults obtained by Bauer et a I2 from the soil experiment fields of Illinois
show that some soils respond highly to phosphate fertilization, while
others give a very low response or none. Reports from county farm
advisers and farmers in general are in agreement with these experi-
mental results.
A simple field test has been devised at the Illinois Station which
will distinguish soils having a high amount of available phosphorus
from those having a low amount. It is the purpose of this bulletin to
describe this test and to show its agreement with soil productivity, and
with crop response to phosphate fertilizers.
Since this test uses the common colorimetric method for phos-
phorus, a review of the- application of the latter to soil research by
other investigators is given.
DEVELOPMENT OF THE COLORIMETRIC METHOD OF
TESTING SOILS FOR PHOSPHORUS
In 1920 Bell and I)oisy! in America, and Deniges1 in France, pub-
lished methods for the colorimetric determination of small amounts
of phosphorus present as phosphate, by means of the blue color pro-
duced when a. reducing agent is added to an acid solution of ammoni-
um molybdate containing inorganic phosphates.
In 1924 Atkins' applied the Deniges method as slightly modified
by FlorentilV to soil extracts. His application consisted in shaking 10
grams of 100-mesh soil for three to four hours in 50 cc. of conductivity
water, Five cubic centimeters of the cent rifuged extract were made
up to 100 cc. with the proper amount of molybdate reagent and the
developed color was then compared with a standard phosphate solu-
tion. His 1:5 extract showed less than two parts per million of phos-
phorus with most soils, unless the soil had been enriched artificially.
The Ohio Station is using a modification of Atkin's method in a port-
able field laboratory.1''
Parker and Fudge" have studied the Deniges method, applying it
592 BUU.KTIN Xo. 337
to the determination of small amounts of phosphorus in soil extracts
and in the displaced soil solution. a
Spunvay'-' has also modified this method and obtained an indication
of the available phosphorus in the field by extracting a small sample
of soil in a folded wax paper with very dilute nitric acid. To two
drops of the extract are added two drops of a nitric acid-ammonium
molybdatc solution and the color developed after stirring with a tin
rod. The color obtained this way fades rapidly. When the Spunvay
method was applied at the Illinois Station to soils of the various ex-
periment fields, it was found that in general a blue color was obtained
only on soils which had been treated with phosphate fertilizers. In the
case of soils testing "high" by the method devised at this Station, it
was possible to get a blue color but in most cases only after consider-
ably more prolonged contact of soil with the extracting solution than
is recommended by Spunvay. Xo test color was obtained with the
Spunvay test with any soils testing either "medium" or "doubtful" by
the Illinois test regardless of the responsiveness of such soils to phos-
phate fertilization. That is to say. the range in available phosphorus
concentration within which differences were observable appeared to be
confined to soils which had received phosphate applications and to
soils which, tho untreated, were extremely high in available phos-
phorus.
The term "high" in available phosphorus is used in this bulletin
to mean high amounts with respect to adequacy in grain farming as in-
dicated by lack of response of these crops to phosphate fertilization. It
is conceivable that a high amount for grain farming may be an inade-
quate amount for truck crops. The results of a qualitative test of this
type depend upon several factors, the most important here being the
time of reaction with the soil and the acid concentration. An increase
in the time of reaction or in acid concentration up to a certain point
results in a darker color. It is thus possible to obtain no color, a light
blue color, or a dark blue color with the same soil sample by varying
the acid concentration of the extracting solution. Thus it is seen that
a qualitative test means nothing until it has been standardized by com-
parison with crop yields and phosphate responses. This Spunvay has
done with his test with reference to truck crop soils, and he has ob-
tained satisfactory results. It is obviously incorrect to compare a test
standardized for truck crop conditions with one standardized for grain
crops. The above discussion, centering around Spunvay 's test, has
been given in order to bring out the need of a different test which
would be applicable to general farming conditions, rather than to show
or infer any superiority of one test over the other.
Analvt. Ed.. In.lus. Knsin. Chom. 1, 136. 1929.
A FIKI.I) TKST FOR AVAII.AI.LI-: Pnnsi'iioiu's ix SOILS o'lo
THE ILLINOIS ADAPTATION OF THE
COLORIMETRIC TEST
The following test. devised at this Station, differs from that of
Spurway in tat range of available phosphorus detected, ibi method
of operation, i c i kind of acid used, idi concentration of reagents and
(el permanency of the blue color. It has proved to be a reliable index
of the available phosphorus status of the soil and shows promise of
becoming a serviceable test, not only for the soil chemist, but also for
the county farm adviser and the farmer.
The Reagents Used
The solution with which the test, is made is prepared as follows:
Dissolve 100 grams of highest purity ammonium molybdate, phos-
phate free, in 850 ce. of distilled water. Filter the solution and cool it.
Then add it slowly with constant stirring to a cold mixture of 1.700 cc.
of concentrated hydrochloric acid (30 percent) and 700 cc. of water.
This is the stock solution. The solution as used for the test is made
by diluting 120 cc. of the stock solution to 1.000 cc. with distilled
water. In addition to the solution a small tin rod as recommended by
Spurway is required for the lest. A piece of solder wire is quite satis-
factory altho slower than pure tin in developing the blue color.
The acid concentration has been carefully worked out. Slight vari-
ations are permissable but a large increase in the concentration of acid
used results in a colorless test, even when phosphates are present in
large amounts. A large decrease in the acid concentration will result
in the test solution itself giving a blue color when stirred with the tin
rod even tho phosphates may be absent. However, the slight dilution
caused by the water in wet soils has no effect on the results. The solu-
tion alone when freshly prepared should give no color when stirred
with the tin rod. After standing for a few weeks it will develop a
slight blue color upon being stirred with the tin rod. This does not in-
terfere with its use since1 the small quantity of the material giving
the blue color is absorbed by the soil in making the test, so that soils
which would give a "low" test will .-till give a "low" test with the aged
solution. If more than a slight blue appears in the solution when it is
stirred, that is an indication that the solution has been contaminated
with phosphorus and should not be used. Arsenic, which may be pres-
ent in the -oils of orchards >prayed with arsenic sprays, gives a blue
test color.
Making the Test
The test is made by shaking 1 part of soil with about 3 parts of
the solution in a small test tube or vial. Only enough shaking to mix
the soil and solution is required. "When settled, after about live minutes,
the soil should occupy about one-third of the tube and the solution
two-thirds. The clear solution is then stirred gently with a tin rod
and without disturbing the settled soil until maximum intensity of
594 BULLETIN No. 337 [August,
color develops. This requires from 10 to 20 seconds, depending upon
the amount of phosphate present. The tin dissolves in the acid solution
and brings about the reducing action necessary for the production of
the blue color. The varying amounts of phosphate present are indi-
cated by a series of increasing color intensities and shades. These
range from very light green thru light greenish blue to a deep blue.
The color chart presented here shows only four color variations. The
first is colorless; the second, light green; the third, greenish blue; and
the fourth, medium blue.
To simplify the recording of the color readings, any test which is
colorless or nearly so is called "low.'' A test color which approximates
the second color shown is recorded as '''doubtful." One varying around
the third color is called "medium.'' while one giving a color as deep as.
or deeper than, the last is "high." Since the amount of the blue com-
pound is directly dependent upon the amount of phosphorus extracted
from the soil by the acid solution, these colors have also been desig-
nated to mean "low."' "doubtful/' ''medium," and '"'high" amounts of
available phosphorus:1 The color gradually fades upon standing, altho
contrasts between different samples may often be observed after an
hour. Some "high" test- have retained a good blue color even after
24 hours. Clear solutions containing phosphates but without the pres-
ence of soil show only a slight decrease in color after standing for
three days. If desired, the faded color may be redeveloped by stirring
again with the tin rod. altho if allowed to stand over night the re-
developed color is usually darker than the original.
The determination of the color range with its corresponding signi-
ficance in regard to available phosphorus has been based entirely upon
what is known about the response of grain and legume crops to phos-
phate fertilization in the field. Xo attempt has been made to correlate
the results of this test with the response to phosphate fertilization of
truck or other special crops, and for the present its use should there-
fore be restricted to general farms growing the usual grain and hay
crops.
Effect of Carbonates. Free carbonates in small amounts influence
this test by producing a bluish green to green color rather than blue
thruout the entire range of intensities. This, however, does not inter-
fere with the use of the test, since the depth of color, whether green or
blue, is the indicator of the relative amounts of available phosphorus.
If, however, they arc present in large amounts, so that a continuous
effervescence results the test cannot be relied upon. The resulting de-
crease in the acid concentration makes the solution useless and for the
present no means of overcoming this difficulty is known.
Doubtful
COLOR CHART OF TEST FOR AVAILABLE PHOSPHORUS
"Low" indicates a deficiency of available phosphorus for average
crop growth.
"Doubtful" indicates that phosphorus is present in somewhat larger
amount but it is uncertain whether the supply is sufficient for average
yields.
"Medium" and "High" represent still larger amounts of available
phosphorus — amounts that in general will be adequate for average
to high yields.
_//)-?.''] A FIKLD 'I'KST i-'cm AVAIL. \HI.K PiHisi'iioKrs ix SOILS r>9f>
Effect of Moisture. Tin' test ni:iy be used on wet soils taken di-
rectly from the field or on dried samples. The dried samples are prefer-
able -hire they settle more quickly in the test tube and give a clearer
solution. The soil may be ground or unground and the amount used
may vary as much as 25 percent in proportion to the volume of re-
agents used without' producing an appreciable difference in the re-
sult s.
Applying the Test in the Field
A number of individual soil samples should be obtained from points
we'd di-iributed over the field and te-ted separately. The plan of sam-
pling a field as recommended by Linsley and Bauer7 for the acidity
te-t i- very -ati-factory. Such a plan of systematic testing makes pos-
sible mapping of the soil of a. given field with respect to the relative
abundance of available phosphorus. Obviously, a test of a single sam-
ple or of a composite -ample made by mixing the samples obtained at
various point- fails to give an accurate picture of the available phos-
phorus status of the field.
The surface samples .-hould be collected at a depth of an inch or
t \\ o in order to avoid surface litter, using care that they are not taken
from under manure or decaying organic matter, because of the local
accumulation of available phosphorus from these materials by leach-
ing.
In addition to the surface soil, samples from lower depths should
also be tested. This is particularly desirable in case the surface soil is
found to he deficient in available phosphorus, since there is the possi-
bility of encountering available phosphorus within the feeding range
of the crop roots. As a matter of fact, most of the soils tested thu- far
showing negative result-' in the surface have been found to give a
medium TO high te-t at Mime depth. This depth has varied from 10 to
more than 40 inches.
-ome of the uncertainty irom phos-
phate fertilization. No ie-t can he expected to eliminate all such un-
certainty. because1 -ome field- which are deficient in available phos-
phoru- may not re-pond profitably to plmsphale applications due to
the lack of potassium oi1 to -ome other limiting factor. This ie-t i- only
recommended as a mean- oi determining whether a -oil i- already -uf-
ficiently high in available phosphorus that phosphates may be elim-
inated for (he present, a' !ea-t. imm the -oil improvement program.
RESULTS OF THE TEST ON THE ILLINOIS SOIL
EXPERIMENT FIELDS
590 BI-LLETIX Xii. ,337
used on more than 500 samples from the check plots of 31 experiment
fields located in different parts of the state and also on samples from
farms and demonstration plots. The results of these tests have been
found to be in good accord not only with response to phosphate fertili-
zation, but also with the productivity of the untreated soil.
A summary of these results, together with the ranking of the dif-
ferent fields as to the productivity of the untreated soils on which the
tests were made, and also with the most profitable system of soil treat-
ment on the respective fields is shown in Table 1. The ranking in
productivity is determined from the value of the crops harvested from
the untreated plots. It is necessary to use crop values rather than
yields in order to express the average of all crops by a single figure.
Average December 1 crop values on the farm for the last four years
are used. The determination of the most profitable system of soil treat-
ment is based upon the results of 13 to 30 years of cropping on these
fields under the various treatments. The table is divided into two parts
representing, respectively, the dark-colored soils of the northern two-
thirds of the state and the light-colored soils of the southern third.
Results on Dark-Colored Soils
Considering the dark-colored soils, the average annual acre crop
values on untreated land, based upon the rotation period ending in
1927, are as follows: those giving a "high" phosphorus test, 833.88;
those testing ''medium," 828.24; and those testing "low," 824.26. This
is an increase of 39 percent on the field- testing '•high" above those
testing "low."
The first six fields (Table 1) whose check plots test "high" or
"medium'' are highest in order of productivity. In no case was phos-
phate included in the most profitable system of soil treatment. While
the Lebanon field is much lower in productiveness than the above six
fields, the most profitable treatment does not include phosphate. The
"medium" test shows this soil to be fairly well supplied with available
phosphorus.
On the next three fields. Sidell. Carthage, and Carlinville. about
half of the check plots show a "medium" to ''high" test, while the re-
mainder are "low." These fields are in the intermediate group so far
as response to phosphate fertilization is concerned. They are also lower
in natural productiveness than some of the fields. This is due in part
apparently to a deficiency in available potassium, since these fields
lead those on dark-colored soils in response to potassium fertilization.
Starting with the Kewanee field, the rest of the fields on dark-
colored soils give a "low" test and with the exception of Mt. Morris
and Dixon. these fields all include phosphates in the most profitable
system of soil treatment.
A FIKI.I) TKST rou AVAII.AHI.K Pnosi'iioin s i\ Son.
TAHI.K 1. — RKSCI.TS OF AVAII.AHI.K PIIOSPIIOUUS TKST. HANK ix Piin
AND M()ST PliOFITAlil.K Soil. TliKATMKXT OX Jl.I.IXOIS Soil,
KN T l'"l KI.DS
Kaiik in Annual acre
Most profit
Field
Predominating soil type
Phosphorus produc- ."up values
able soil
test tiviiv lor untreated
treatment
land
system1
Dark-colored soils
McXabb
Brown Silt Loam
I, Muscatine silt loam)
High 1
$39 91
None
\ledo
Brown Silt Loam On Clay
vGrundy silt loam) Medium 2
34.05
KL
1 -iMoille
Black Clav Loam, poorly drained phase
(.Loessial clyde clay loam) High
3 32.90
KL
Brown Silt Loam
Medium
( Muscatine silt loam)
to low J
Hartsburu
Black Clay Loam
i Grundy clay loam)
High 4 31.lt
K
Minonk
Black Clay Loam, poorly drained phase
(.Loessial clyde clay loam)
High 5
31.19
K
Spring Valley
Brownish Yellow Gray Silt Loam
(Clinton silt loam)
Medium 0
31.11
K
1 ebanon
Grayish Brown Silt Loam On Tight day
(.Grundy silt loam, grayish phase) Medium 14
21.58
KL
Side!!
Brown Silt Loam
iMuscatine silt loam) Low
10 25 00
RLPK
Black Clay Loam, poorly drained phase
(Loessial clyde clay loam)
High
1 'arthage
Black Silly Clay Loam On Clay
(Grundy silty clay loam) \ Medium
12 23.43
KLl'K
Grayish Brown Sill Loam On Tight Clay
(Grundy silt loam, grayish phase)
Low
( 'arlinville
Grayish Brown Silt Loam On Tight Clay
! Grundy silt loam, grayish phase)
Series 100 and 20(1
Medium
Series 300 and 400
Low 13
21.81
RLPK
Kewanee
Brown Silt Loam
I Muscatine silt loam)
Low 7
29.94
RLP
Mt. Morris
Light Brown Silt Loam
iTama silt loam)
Low 8
20.00
RL
Urbana
Brown Silt Loam
1 Muscatine silt loam)
Low 9 20 59
RLP
Dixon
Brown Silt Loam
i Muscatine sill loam)
Low-
11 25.07
RL
Light Brown Silt Loam
(Tama silt loam)
Low
( 'layton
Brown Silt Loam On Clav
'Grundy silt loam) Low 15 21.12
KLl'K
Joliet
Brown Siit Loam On Calcareous Drift
'Clarion silt loam; Low 10 1!) 53
RLP
•K = residues, L --limestone, 1' = rock phosphate, and K = potassium.
59S
BULLKTIX Xo. 337
TABLE 1. — Concluded
[August,
Fiel
Rank in An!!'ja! ,acre Mof* Pro.^-
prcxluc- crop values able soil
tivitv *or untreated treatment
land system
Light-colored soils
Oquawka
. . . Dune Sand, Terrace
(Plainfield sand) . High
Gray Silt Loam On Tight Clav Low
1 ill. 87 RL
2 11.21 RLPK
Toledo
. . . Gray Silt Loam On Tieht Clav Low
3 7.42 RLPK
Unionville
. . . Yellow-Gray Silt Loam : Low to
medium
Gray Silt Loam On Orange Mottled Tight
4 7.35 RLPK
Enfield
Clay Low
. . Light Gray Silt Loam On Tight Clay Low
5 G.45 RLPK
6 5.08 RLPK
Gray Silt Loam On Orange Mottled Tight
Clay Low
Yellow-Gray Silt Loam On Tight Clav Low
Odin
Gray Silt Loam On Orange Mottled Tight
Clay Low
Gray Silt Loam On Tight Clay
Gray Siit Loam On Tight Clav Low
7 5.91 RLPK
8 5.77 RLPK
Gray Silt Loam On Tight Clav Low
Yellow-Gray Siit Loam On Tight Clay Low
Grav Silt Loam On Tight Clav Low
9 5.05 RLPK
10 4 57 RLPK
Elizabethtowr.
Sparta
. . . Yellow Silt Loam Low
Yellow-Gray Silt Loam On Medium Plas-
tic Clay Low
. . . Light Gray Silt Loam On Tight Clay Medium
11 4 55 RLPK
12 3.99 RL
Results on Light-Colored Soils
Excluding the Oquawka field, which is dune sand, the light-colored
-oils are almost uniformly '''low" in available phosphorus and they re-
spond to phosphate fertilization. The Sparta field shows ••medium" on
most of its check plots and does not respond to phosphates. The Union-
ville field shows a slight color on several plots and the Elizabethtown
field shows a "medium" color on one check plot. In the above dis-
cussion, increases indicated for phosphate applications have been based
on rock phosphate used in a grain system of farming.
Figure 1 shows the relation between the percentage increases in
crop yields due to phosphate applications on the various experiment
fields and the results obtained by the test. The agreement between
tost color and percentage increase in yield is very good, altho there are
no sharp breaks between the "high." "medium," and "low" testing
fields. These figures arc based on the rotation endinc; in 1927.
A FIKI.D TKST KOU AVAIL. \HI.I-: Pnosi'iioiirs ix Son.*
PERCENTAGE INCREASE FOR PHOSPHATE
en
CD
ElizabetMown
West 5alem
Newton
Raleigh
Jol.et
Enfield
Ewng
Urbana
Union^ille
Oblong
Toledo
Sidell
Kewanee
Clayton
Carlinvilte
Dixon
Mt. Morris
Lebanon
Hartsburg
Carthage
Aledo
Minonk
McNabb
Sparta
LaMoille
Spring Valley
Oquawka
]TEST LOW ON CHECK PLOTS.
LOW ON SOME CHECK PLOT5;
MEDIUM TO HIGH ON OTHERS.
TEST MEDIUM TO HIGH ON CHECK PLOTS.
GOO
BULLETIN Xo. 337
On some experiment fields soil variation with respect to the test
was very marked, results of '"low," "medium," and "high" being ob-
tained on the different check plots of the same field. In a number of
such cases the average yields of corn, oats, and wheat were computed
separately for these plots and are plotted in Fig. 2. Here again satis-
factory agreement is observed between the productive level of the soil
• i PHOSPHORUS TEST MEDIUM_TOJIGH.
D PHOSPHORUS TEST LOW.
TO
OflTS CORN WHEflT
CARTHAGE
OftTS CORN WHEflT
MINONK
OUTS CORN WHEflT BlFfllFfl
URBANfl "
FIG. 2. — RELATION BETWEEN AVAILABLE PHOSPHORUS TEST AND THE PRO-
DUCTIVE LEVEL OF UNTREATED SOILS OF THE ILLINOIS SOIL
EXPERIMENT FIELDS
Each pair of contiguous bars represents the crop yield of a high
testing and a low testing check plot in the same series of a given experi-
ment field. With the exception of the oats crop at Urbana, the high
testing plot outyielded the corresponding low testing plot.
and its reaction to the test. For instance, the untreated Check Plot 110
on the Minonk field tests "low" and the yields of oats, corn, and wheat,
respectively, are 54.1, 48.5, and 23.7 bushels. Check Plot 101. of the
same series, likewise untreated, tests "high" and has produced average
yields of 58.9, 54.7. and 42.5 bushels of the three respective crops.
Effect of Soil Treatments on Available Phosphorus
The effect of soil treatments on available phosphorus is readily
shown by this field test. Plots receiving residues only on the Urbana
field, for example, showed a "low" but the test color was slightly darker
than that for the check plot. The manured plots on the above field
and also on the Joliet field showed still more test color over the check.
The plots in the northwest rotation of the Urbana South Farm, which
receives 45 tons of manure every three years, show a "high" while the
A FIKI.I) TKST KOI; AVAII.AHI.K 1'iiospiiours i\ Son.
taken immediately beneath fresh manure show a "hiiih" test, altho at
a depth of two to three indies the soil may test "low."
All plots receiving phosphate treatment show a ti'ood hhie color.
l"nevenne-s in distribution of added phosphate is sometime-; indicated
by lack of uniformity in the depth of the color in individual tests. The
higher rates of application result in deeper color. Plot 110-W of the
Davenport Series at Urbana. which has received approximately (10.000
]uiunds an acre of rock phosphate, i^ives a deep blue-black color.
Where 13.1200 pounds an acre of rock phosphate had been applied 10
other parts of this field, the soil <^ave a deep blue, gradually decreasing
in intensity to a depth of 30 inches, while the adjacent tinphosplmted
plot showed a colorless test thruout this depth.
Since any form of phosphate fertilizer, regardless of its chemical
nature or fineness of division, will pve the blue color when added to
the soil, it is apparent that this test cannot be used to demonstrate
the value of any particular form of phosphate fertilizer as compared
to another, nor to discriminate between various forms of phosphate
fertilizer.
Available Phosphorus Found at Various Depths
Some interesting observations have been made on subsurface and
subsoil availability. Where a "medium" or ''hiidi'' test is found in the
surface soil, the color intensity increases in the lower levels unless tin-
surface color has been caused by phosphate fertilization.
Where a "low'' test is found on the surface, this ''low" test may
persist down to 40 inches or more1 or, attain, there may be a gradual
increase1 in color until a "hiu'h" test is secured at some intermediate
depth. Within any given area which varies with respect to this test, the
deeper test color on surface soil is usually to be found in lower lyinu'
land, while the elevations are more likely to uive a "medium" or "low"
test .
The existence of variation within a uiiven area emphasizes the
desirability of mapping the areas of "hiidi." "medium," and ''low''
available phosphorus in a iiiven farm or field in order that the need-
le-- application of phosphate fertilizers may be avoided.
SUMMARY AND CONCLUSIONS
1. A field test for available phosphorus has been described which
is recommended for the use of farm advisers and farmer- because oi
its simplicity of operation and practical application.
2. When applied to tin1 untreated soils of the Illiuoi- Kxperiment
1'ields a <iood agreement was found between the results of the lest
and the crop increase- resulting; from the addition of rock phosphate.
602 BULLETIN Xo. 337
3. Those soils which tested low in available phosphorus gave
medium to high crop increases when phosphates were added. In all
hut two of these fields the phosphate treatment was profitable. On
these two fields the treatment came within a few cents of paying for
itself.
4. The soils which tested medium to high in available phosphorus
gave little or no crop increase when phosphate was added. In no case
was the treatment profitable.
5. The productiveness of untreated soils was generally higher where
the test showed a good amount of available phosphorus.
6. All phosphated soils tested high in available phosphorus and
those to which large amounts of manure had been added also gave
a blue color.
LITERATURE CITED
1. Atkins. W. R. G. The rapid determination of available phosphates in soils by
the Coeruleo-Molybdate reaction of Deniges. Jour. Agr. Sci. 14. part 2,
192-197. 1924.
2. Bauer. F. C.. Smith. R. S.. and Smith. L. H. The Illinois soil experiment
fields. 111. Agr. Exp. Sta. Bui. 273, 41-327. 1926.
3. Bell. R. D.. and Doisy, E. A. A rapid colorimetric method for the determina-
tion of phosphorus in urine and blood. Jour. Biol. Chem. 44, 55-67. 1920.
4. Deniges. G. Reaction de coloration extremement sensible des phosphates et des
arseniates. Ses applications. Compt. Rend. Acad. Sci. (Paris), 171, 802-804,
1920.
5. Florentin. D. Determination de phosphate dans 1'eau. Ann. Chim. Analyt. 3,
295-296. 1921.
6. Jones. Earl. The portable soil laboratory and the Ohio method of testing
soils for acidity. Jour. Amer. Soc. Agron. 21, 381-384. 1929.
7. Linsiey. Clyde M.. and Bauer. F. C. Test your soil for acidity. 111. Agr. Exp.
Sta. Circ. 346. 1929.
8. Parker. F. W.. and Fudge. F. Soil phosphorus studies: 1. The colorimetric de-
termination of organic and inorganic phosphorus in soil extracts and the
soil solution. Soil Sci. 24, 109-117. 1927.
9. Spurway, C. H. Test soils for water soluble phosphorus. Mich. Quar. Bui. 9,
64-67. 1926.
AUTHOU INDEX
AUTHOR INDEX
PAGE
Ashby, R. C. Practices and Prob-
lems of Cooperative Live-
stock Shipping Associations
in Illinois 349-72
Hauer. F. C. Crop Yields From
Illinois Soil lOxperiment
Fields in 1928 209-240
Herg. H. A.. Case, H. C. M., and
Wileox. R. II. Organizing the
Corn-Helt. Farm for Profit-
able Production 257-332
Hray. R. H. A Field Test for
Available Phosphorus in
Soils 589-604
Hull. Sleeter, and Longwell, J. H.
Relative lOconomy of the
Various Cuts of Pork. .. .333-348
Case, II. C. M., Mumford, II. W.,
Stewart . C. L., and Johnston,
1'. F. Developmental Study
of a Rural-Urban Trade
Area 129*-208
Case, IF C. M., Wileox. R. IL,
and Herg, IL A. Organizing
(hi1 Corn-Belt Farm for Prof-
itable Production 257-332
Johnston. P. 10., Mumford. II. W.,
Stewart, C. L., and Case, II.
C. M. Developmental Study
of a Rural-Urban Trade
Area 129*-20S
Kingsley, F. C., and Lehmann, 10.
W. Fleet ric Power for the
Farm 373-380
Knox. John II. , and Snapp, Ros-
coe R. Summer Rations for
Fattening Steers 241-256
Lehmann, 10. W., and Kingsley,
F. C. Fleet ric Power for the
Farm 373-380
Lloyd, J. W., and Newell, II. M.
Observations on the Refrig-
eration of Some Illinois
Fruits in Transit ; .509-544
Longwell. J. IL, and Hull, Sleeter.
Relative Feonomy of the
Various Cuts of Pork ... .333 348
Mumford, II. W., Stewart. C. L.,
Case, II. C. M., and Johnston,
P. K. Developmental Study
of a Rural-Urban Trade
Area 129+-208
Newell. II. M., and Lloyd. J. W.
Observations on the Refng-
erat ion o I S o m e Illinois
Fruits in 'Transit 509 544
Norton, L. J., and Stewart, C. L.
Seasonal Features of Illinois
C.rain Marketing 1-4S
Overmann. O. R., Sanmann, F. P.,
and Wright, K. JO. Studies
of the Composition of Milk..
49-176*
Ruehe, II. A., and Tracy. P. II.
Fn/yme Activity of Ice-
( 'ream Improvers 481- 508
Sanmann. F. I'., Overmann, O. R.,
and Wright, K. 10. Studies
of t he Composition of Milk . .
49-176
Sayre, C. H. Quality in Celery
as Related to St met lire . .557- 588
Snapp, Roscoe, R., and Knox,
John H. Summer Rations for
Fat tening Steers 21 1-256
Stewart, C. L., Mumford, II. W.,
Case. II. C. M.. and Johnston,
P. 10. Developmental Study
of a Rural-Urban Trade
Area 129*-208
Stewart, C. L.. and Norton. F. J.
Seasonal Features of Illinois
(Ira in Marketing 1 48
Tracy, P. IF, and Ruehe. IF A.
JOn/yme Activity of Ice-
Cream Improvers 481 508
Wilcox, R. IF, Case, II. C. M.,
and Herg. II. A. Organi/ing
the Corn-Helt, Farm for Prof-
itable Production 257 332
Woodworth, C. M. Illini Soy-
beans 545 516
Wright. K. F., Overmann. O. R..
and Sanmann, F. P. Studies
of the Composition of Milk
.. 49-176
INDEX
INDEX
Account intr. sec Farm accounting
Aledo experiment Hold yields. .213-14
Alfalfa. place of in farm organi-
zation 269
Antiocli experiment field yields. . 214
Harley, place <>i in farm organi-
zation 266-67
Bloomington experiment field
yields 214
Carlinville experiment field yields 215
Carthaee experiment field yields
. .'...215-16
Cattle, N( c Steers
Celery, structure of plant 561-66
study of quality in as related
TO structure 559-SS
effect on quality of fertilizers 569
of method of blanching. .569-70
of supplementary irriira-
tion .' .570-71
laboratory technic 571-72
!it( rature cited 5SS
piwious studies of 559-61
re.-uhs oi microscopic exami-
nat ions 573-S5
summary and conclusions. .5S5-S7
varioi ies tested 566-67
comparison of 567-69
Clayton experiment field yields.. 216
Clovers, place of m farm organi-
zation 269
Corn, marketinu: studies of, see
C I rain market ing
production costs of 262-66
factors affecting 330
Corn drier, electric 433-36
( 'urn. elevator, electric 431 33
Costs of production, factors af-
fect iiiLr 330
of grains and hays 262-70
as afft cted by yield 262-64
Cre;<m separators, use of elec-
tricity with 452-51
Crop diversification, advantages
of 2s5-s7. 293-96
Crop yields, factors affecting.... 331
on experiment fields, 192s. . .210-3S
possibility for improvement in
'. 15S-60|:
Hairy products, marketinu; of..!79-S2
study of production and con-
sumption of 162-67*
Davi npurl plot yields, 192S 237
Dixon experiment field yields. .216-17
Egirs, demand for improvement
in production of 170-71
production and consumption of
167-71*
Electric plants, farm 472-73
Electric power for farms, study of
'377-479
construction of experimental
line 3S5-S9
data from farms on experi-
mental line 378— So
discussion of rates 466-71
energy consumption on each
farm 3S9-100
farm production use 429-66
advantages of portable motor
for.. 429-30
cream separating 452-54
drying grains and SIMM! ... .433-36
elevating corn 431-33
incubating and brooding. . .460-61
milking 447-51
oat hulling 445-47
painting, spray 454-57
poultry house lighting 457-60
pumping 451
seed germination 461-66
seed treatment 466
household use 401-29
buttermaking 427
coffee percolating 419-20
cooking 415-19
dishwashing 425-27
effect of on lime saving 403
food mixing 419
ironing 411-15
lighting and minor appli-
ances 427-29
pumping 403-407
refrigeration 420-25
washing 409-15
water heating 407-409
preliminary survey of equip-
ment used 2S3-S5
summary 478-7!)
HI < nl*n Electric plants, farm
Eleciric transmission lines in Illi-
nois 376
Electricity, energy consumption
of for various operations. .474-78
time used in consumption of
1 kilowatt by various
pieces of equipment 474
I NDKX
F.le\ lit ill's, .s'( i ( iraitl elevaf ors
Fli/abet htown experiment field
yields ....................... '_MS
Knlield experiment tirld yields. 2IS-1!)
F.quipment costs. regulation of
farm ..................... 2sl S)>
F.wintr. experiment field yields.. 210 '20
Fxperiment field yields. 1928. ..210-38
Farm accounting. value of ......
........... . ....... 2!)l-!>2. )V27 ;]_>
Farm earnings in east central llli-
noiH ......................... 32!)
in noi't hwestern Illinois ..... 1 I!)-")!!*
Farm labor. M i Labor
Farm oriram/at ion, da! a from MIC-
ces>ful ........... I.");!-.")!, M27 ii'2*
principles of .uood ........... 2C>2 !»()
MI ('onleiils ................ 2.")S
I''arm ] lower, distribution of t hru-
0111 year ................. 27S, 2S1
xi i nixa Labor and Tractois
Farm products, marketing of.. 17!) S.">
slii pint 'Ills of in and out of area
und'T >tud.v ............ 1 i:i 1.")*
study of production and con-
sum pi ion of ............ b)7 7!)*
transportation used for ..... 17!), ISO
Farm purchases and sales, study
of .......................... II,")"
Fanning, planning a profitable
system of ................ 2!)l-;>27
.s-( i Contents .................. 2.">S
r'arminti-type areas of Illinois ... 117*
r'arms. number of per square mile
in count n 's .................. l!7!)
selection and purchase of. . . .)'>2f>-27
l''armsteads. plannintr of .............
................... 2S1 S.'). ;•',!!) 2.")
I'Vuits, market imr of .......... 170-S2
production and consumption
of ..................... 171 71:::
refriu'erat ion of in transit ....511-11
x< c ( 'ontents ................ 510
(Irain ele\'ators, comjiarat i\'e s(>a-
sons of purcliase and ship-
meiit by country ........... )!l-.'!7
comparison of >ea^onal acti\'iiy
by farmers' and by private
..................... )!7. )!!), li'i
si oraire ca paciiy of I Ilinois
country ....... » ....... 21 27. ;!!)
(Jrain market imr. >t udy of ...... )!!(')
corn, distribution of shipments
«.f ................ 12-1)!. I)!. 15
>ectional differences in.... 11
seasoiia 1 change- in prices of 1 1 17
oafs, earnings on hedged and
un 1 led tred ................ 22 21
distribution of sliipmetits of
................ 17-1!). 11, 15
sect ional differences in . . 1!)
.
sea>i>nal chalices ill prict S of
....................... 1!) 22
win :i I . disl ribut ion < u .-In j >-
meiils of .................. ! 5
Mdioml differences in....
................. "> li. 12. 15
seasonal changes in prices of li 12
*< , <il.«> Cram elevators and
(Irani storati'i
drain storage on farms ........ 27-)!l
influence of on time of sale...
...................... :;•_':: I. ;;<i
Crams. production costs of ...... 2(>5
profits from ................. 2d(i d7
( Irinders, elect i'ic .............. \',\7 !.">
Hartsbur^- experiment In Id yields 221
Ha\'s, cost of producing ......... 2(>S
place of in farm oriranixat ion
........................ 2(i7 70
I letiry couniy. Mai i>t ics from . 1H2 207
llo'j.-s I'ollowiiifi sieei'-. u;iin~- made
by .......................... 2.">2
I b >me equipment , d'il a oil .......
..................... l.">:)-.)(i. 207:
ncc al--«> I'llectric po\\'er, house-
hold u >e of
Horse labor, crop requirements
for ...................... '2! I!) ',\()\
variations in cost of. .27(>-7X. 27'J SO
me <ilx<> Labor
Ice-cream improvers, en/vine ac-
ti\ ity of ................. I,s2 .Vis
si'i-. ('onttnis .................. 1S2
.loliet experiment field yields.... 222
Ke\vanee experiment field yields. . 22)!
LaMoille experiment field yields. 22)1
Labor, adapt imr crop plan to )!())! .'!(),")
calendar for. . .Fi^. Is. l)i I ween )!()S
and )',()!»
distribution of in caring lor
livi Mock .............. :!()."> )H)S
efficient use of farm ...........
........... 275 7(1. 2!)<i )!())!. )!OS
re(|uirenn m- of various crops
and farm opera I ions. .. .2!)7 )!05
*' < almi IIor,-e hbor
t-ebanon experiment lit Id yields
I.iveMork. adjustments in pro-
i h ict ion of ................ )!l 7 1M
amounts and kind- of feeds
used b\ ................ )!()!» 10
bahnemir oi \\ith crop produc-
lion .................... )IOs D!
cooperative shipping of, \< :i<\-
imr count n-> m ............ •'!•)!
et'fecl of on farm earmims. . .270 7)i
hbor required in carinir for.)!(H'p )!()7
oppori unit ii s for impro\'em
in roduction of ........ I do d2*
COS
PAGE
Livestock cooperative shipping
assoe'iat ions, accomplishments
ol 352-53
compel it ion of truck operators
with 183
conclusions from study of 371
location of in Illinois 352
managers' commissions of 357
operation and management of
358-67
problems of 367-71
rates charged by 184, 354-57
summary of study of 371-72
volume of business done by...
182-84, 354-58
McXabb experiment field yields.. 224
Markets, roadside 184-85
Milk, studies of composition of..
51-174
sec Contents 50
Milking machines, electric 447-51
Minonk experiment iield yields. . 225
Morrow plots, decline in corn
yield on 288-89
yields for, 1928 238
Mt. Morris experiment field
yields 226
Newton experiment field yields..
.' 226-28
Oats, marketing study of, see
drain marketing
place of in farm organization.. 266
Oblong experiment field yields... 229
Odin experiment field yields. .228, 229
Oquawka experiment field yields. 230
Palestine experiment field .yields
....230-31
Phosphorus, available', develop-
ment of colonmetric test for
591-92
effect of soil treatments on. 600 601
Illinois adaptation of colorimet-
ric test for 593-602
effect of carbonates a n d
moisture on 594-95
field application of 595
method of making 593-95
reagents used 593
results on experiment fields..
595-001
summary and conclusions 001 002
variation in depth of 001
Pork, method of calculating
economy of cuts 340—17
percentages which cuts consti-
tute of carcass of 337
physical composition of cuts of
. 330-10
prices ol affected by consumer
preference 335
relative- costs of edible and e)f
PACK
lean meats of 340—17
wholesale' cuts eif 331
Potatoes, production and e-on-
sumpt ion of 174-77*
Poultry prexluets, marketing of..
179-82
ne-eel feir impreive-ment in.... 109-71
production and cemsumption
eif 167-69*
Production costs, see Costs of
production
Raleigh e-xpe-riment field yields.. 232
Refrigeration of fruits, see- Fruits
Rock Island e'emnty, statistics
from 192-207
Scott, county, Iowa, statistics
from....'.. 192-93, 201
Seed gcrminators, electric 461-65
Seed-treating machines, electric.. 466
Sidell experiment fielel yielels. . . . 233
Silage emitters, e-Iectrie- 436-37
Soil experiment lie-Ids, yields on,
1928 .' 210 38
Soybeans, place of in farm or-
ganization 207
Illini, adaptability of 555-50
characteristics of 547-52
oil cemtent eif 554
origin of 547
summary of stuely of 546
yielels of 552-54
Sparta experiment, fielel yielels. .233-31
Spring Valley experiment fielel
yields ..." 23 1
Ste-ers, summer rations for fat-
tening 243-55
amounts of feed consumed. . .245— 47
feeel replacement value of
pasture; 250-52
feeels consumed per 100-pound
gain 249-50
financial outceime 252-54
gains maele 247—19
plan of e-xperiment 243—15
summary 251, 255
Toledo experiment field yie-lds... 235
Trae-tor costs,' variatiems in 278
Tractor peiwer use-el feir various
e'reips 296-97. 299-301, 301
Trade- ami, stuelv of rural-
urban ' 130-208*
see Conte-nts 130
Truck transportation e)f live-
stock 182-84
Fnionville e-xpe-riment field yielels
'. .. 236-37
Urbana, experiment fie-ld yields 237-38
Vegetables, marketing of 179-82
production and e'onsumption eif
.. 177 79
•Bulletin 320.
IM.KK
PACK
Wheat. markrtinii Miuly (if. Kit
( I r,-i in market mil
lace1 of in farm t>rir;tni/:tt i«m . . -(id
- '9.30
OF ULlHois
•••— — — —
UNIVERSITY OF ILLINOIS-URBANA
Q 630.7IL6B C002
BULLETIN. URBANA
324-3371929
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