boron in tre 1krigation waters and amaline...
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BORON IN TRE 1kRIGATION WATERS AND AMALINE
OALCAREOUS SOILS OF ARIZONA WITH PARTICULAR
REFERENCE TO ITS EFFECT ON PLANTS
by
Earl F. Stark
A Thesis
submitted to the faculty of the
Department of Agricultural Chemistry and Soils
in partial fulfillment of
the requirements for the degree of
Master of Science
in the Graduate College
University of Arizona
1942
7 (,Dector of Thesis I Date
/ 2ABSTRACT
In a partial survey of Arizona waters, surface waters
tested were found to be lower than the accepted toxicity
level for most crops. Some of the pumped irrigation water
analyzed contained excessive amounts of boron; but in most
oases the availability of alternate sources permits blend-
ing of waters so that the problem is obviated.
Analyses bf plant materials show that a correlation
exists between the amount of boron in irrigation water and
the amount of boron taken up by the plant.. Foliar toxicity
symptoms sometimes are evident
Studies were conducted which showed that the amount of
boron fixed by a soil is a function of soil texture, as well
as the boron concentration of the equilibrium solution with
which the soil is in contact. When the, equilibrium concen-
tration of the boron in the two phases was plotted, a linear
relationship existed in which the slope of the fixation curves
for heavy soils contrasted with that for light textured soils.
Data are at hand which indicate that boron fixation is a tem-
porary process, pending percolation of boron-free water
through the soil, the release of boron being enhanced when
the percolating water has a low pH value.
In sand cultures of cotton and sunflower plants grown in
media containing a range of boron and lime concentrations, th
results were interpreted to best advantage by use of the cal-
cium:boron ratio; this fluctuates widely, as does the yield,
when boron is limiting in a soil. Calcium carbonate amelioral
to some extent the toxic effect of boron in plants.
ACKNOWLEDGMENT
The author expresses his deep appreciation
to Professor H.V. Smith, under whose direction
and guidance this investigation was carried out.
To the other members of the Department of
Agricultural Chemistry and Soils he is deeply
indebted for helpful criticisms and suggestions.
His gratitude is extended to Doctor L.M.
Pultz of the Botany Departuent for giving of
his time, especially in the interpretation of
the results.
TkBLE OF CONTENTS
Distribution of Boron in the Irrigation Watersof Arizona 51
Relation of Boron to Fluorine in Waters 66
Boron Content of Plants 68
Summary 76
Bibliography 78
Introduction
Soil Used for the Experimental Phase of
Page
1
This Investigation 8Lime Content or Soils 9Buffer Capacity 11Mechanical Analysis 12Boron Content of Soils 13
Analytical Procedure 15Boron Fixation 29The Absorption of Boron by Phosphates 33Leaching of Soils 35
Plant xperiment 1+1Interpretation of the Sand Culture
Results 1+6
Results with Sunflower as the r2est Plant. 4.7
Interpretation of Graphical SunflowerResults 4.8
Results with Cotton as Test Plant 4.9
LIST OF TABLES
No. page
1 Tolerance of Various Plants for Boron 2
2 The Effect of Percentage Ca1ciii Carbonateon pH and Crop Yields 5
3 The Lime Content, Hydrogen Ion Ooncentron,and the Total and Specific BufferCapacity of the Soils Used in ThisInvestigation 10
/+ Mechanical Analysis of Soils..... ............. 12
5 Boron Content of Soils 13
6 Effect of Ions Other than Boron on theDetermination of Boron by the TurmericMet hod 19
7 Data for Calibration Curves made over a Two-Weeks Period, Using a Permanent DiluteTurmeric Indicator 21
esults of Boron Analyses by the TurmericMethod on Materials used in SandCulture Experiment . . . . . . . . . . ............ 23
9 Nitrate Interference in the Dilute TurmericMethod 25
10 Nitrate Interference with Naftel's TurmericMethod for Boron 26
11 Effect of Decreasing ph on Boron Fixation...., 30
12 The Effect of Calcium Ion on Boron Fixation,., 31
13 Effect of Increasing ph on Boron Fixation, 32
No. Page
14 Fixation of Boron by i.ctivated. Bone andRock Phosphate 34a
15a Percolation Experimental Data.,..,. .... 38
15b Equilibrium Experimental Data 39
15c Leaching Experimental Data 37
16 The Release of Boron During Leaching withSuccessive, Equal Volumes of Boron-FreeSolutions 40
17 The Boron Content of the Component Parts ofSand. Cultures 43
l7a Possible Boron Concentrations of Oven-DryPlant Material Resulting from Absorptionof Boron Added as Contaminant in gand.Culture Materials 43a
18 Data for Sand Culture Plant Experiments -Sunflower 44
19 Data for Sand. Culture Plant ExperimentsCotton 2+5
20 Boron Content of Surface and. UndergroundWater of Arizona 53
21 Boron and Fluorine Concentrations ofWaters 67
22 Boron Content of Lemon Leaves Classifiedwith Reference to the Injurious Effect.., 69
23 Boron Content of Plant Material 70
24 Results of Spectographic Analyses of PlantIViaterials from Grapefruit Afflicted withPinknose 75
LIST OF FIUEihS
No.
1 This Curve and Indicated Points whichDelineate Others Show the Reproducibility of the Calibration Curve used inthe Naftel Turmeric Method, for theDetermination of Boron.
2 Map of Arizona showing Boron Distribution inRelation to Drainage Areas within the State.
3. Spectrograms of Citrus Leaves and Frit.
4 Calibration Curve for the Quinalizarin Method ofDetermining Boron.
5 The Amount of Boron "Fixed by Soil when Shakenwith 0.0, 0.5, 1.0, 5.0, 10,0 p.p.m. BoronSolutions.
6 The Boron in a Soil as Related to Texture andConcentration of Percolating Solution,
7 The Amount of Boron Remaining in a Soil afterleaching with distilled water.
8 The Effect of Hydrogen Ion Concentration onBoron Fixation in Soils.
9 The Relative Fixation of Boron by Rock Phosphateand "Activated" Bone.
is The Effect of Overliming on Yield of Sunflowerat Various Concentrations of Boron in theCulture Solutions.
2s The Relation of the Amount of Calcium in Sunflowerto the Concentration of Boron in the NutrientSolution and to the Calcium:Boron Ratio of thePlant Material.
3s The Relationship of the Amount of Boron in Sunflowerto the Concentration of Boron in the NutrientSolution and the Caleium:Boron Ratio of thePlant Material
FIGURES (cont.)
No.
4.s The Effect of Boron Concentration in the NutrientSolution Upon the Calcium:Boron Ratio atVarious Calcium Carbonate Concentrations inthe Medium.
5s The Effect of Varying the Quantities of Lime andBoron in the Nutrient Solution upon the Yieldof Cotton and Calcium:Boron Ratio in the Plant,
6s The Effect of the Concentration of Boron in theNutrient Solution upon the 1Jeight of BoronAbsorbed and upon the Calcium:Boron atio inSunf lower Plants when the Lime Content of theMedium Varies from 1 -10%.
lc The Effect of Overliming on. the Yield of Cotton atVarious Concentrations of Boron in the CultureSolution.
5c The Effect of Varying the Quantities of Lime anLBoron in the Nutrient Solution upon the Yieldof Cotton, and the Calciinn:Boron Ratio in thePlant.
6o The Effect of Boron Concentration in the NutrientSolution upon the Calcium:Boron Ratio atVarious Calcium Carbonate Concentrations inthe Medium.
lsc The Average Percentage of Phosphorus in Plants asRelated to the Lime Content of the Soil.
2sc The Average Percentage of Iron in the Plant asRelated to the Lime Content of the Soil.
3sc The Optimum Boron Concentration of the Medium forCotton and Sunflower Then the Yield is Averagedfor all Lime Concentrations.
BORON IN THE IRRIGATION VATERS M1) ALKALINECALCAREOUS SOILS OF ARIZONA WITH PARTICULAR
REFERENCE TO ITS EFFECT ON PLA1S
INTRODUCTION
Interest in the boron problem in Arizona was aroused
in 1928 when Kelley and Brown (20) of California showed
that boron in small quantities in irrigation water is re
sponsible for certain injuries to citrus and ialnut trees.
The publications of Wilcox (L6), Scofield. and Wilcox L.2),
and Wilcox and Eaton (16) stimulated further interest in
the problem. JAeanwhile, preliminat'y investigations in
Arizona had shown the presence of toxic concentrations of
boron in local irrigation waters as measured by California
standards. It has not yet been established that boron de
ficiency exists in Arizona soils.
The possibility that boron might be responsible for a
certain unhealthy condition of plants in the southwestern
part of the United States was pointed out by Kellerman in
1920 ( 19). It was his contention that boron could find its
way into irrigation waters from borax deposits, or from
boron minerals which are commonly foun.d. in the soils of the
Southwest. He suggested also that the high toxicity of
some of the alkali soils may be due in part, at least, to
2
soluble boron.
It is an established fact that small quantitIes of
boron are essential to the proper development of growing
plants ( 4.); and, it is equally well established that an ex
cessive amount of boron in the soil or irrigation waters
is definitely toxic to plants (20).
Not all plants require the same amount of boron for
best growth. Some attempts have been made to classify
plants according to their tolerance for boron (15) (36).
Purvis (36) has used the following grouping to designate
the boron sensitivity of various crops.
Tobacco
Eaton (15) has classified additional plants on the
basis of their tolerance for boron. Such trees as citrus
TABLE 1 - TOLERANCE OF VARIOUS PLAJ\TTS FOR BORON
Very3ensitive Sensitive Tolerant
VeryTolerant
Cowpeas Celery Cabbage Okra BeetsCucumbers Muskmelon Carrots Onions Cauli-Snap beans Peas Collards Pepper lowerStrawberries Potatoes Corn Radishes Mustard
Sorghum Cotton Rye TomatoesSquash Eggplant Spinach TurnipsWheat Kale SweetWat erme ion Lettuce potatoes
Lima beans
3
avacado, nut, apple, pear, stone fruits, and others are
sensitive to boron. Many of the truck crops such as lirna
beans, tomatoes, radishes, and sweet potatoes are included
in this group. Among the more common field crops included
in this group are oats, barley, corn, wheat, Pima cotton,
Acala cotton, potato, and sunflower. The tolerant list in-
cludes such crops as carrot, lettuce, cabbage, alfalfa,
mangel, sugar beet, and date palm,
It may possibly be assumed that the more tolerant a
plant is for boron, the higher its boron requirement. How-
ever, as pointed out by Eaton (15), plants which absorb large
quantities of boron are most severely damaged. It is for
this reason that sunflowers and sugar beets are used exper-
imentally to determine boron deficiency in a soil.
Soil investigators have long been familiar with the
injurious effects of overliming some of the more acid. soils
of the humid region. Midgley (25) in 1932 attributed it to
the presence of soluble calcium in the soil solution, even
though he could not reproduce the injury with soluble cal-
cium salts or bicarbonates. Pierre and Browning (35) as
late as 1935 regarded the injury solely as one of disturbed
phosphate nutrition.
In 1937 Naftel (30) presented evidence showing the
chief reason for overilining injury was an induced boron
4
deficiency. Since that time many investigators have at
tempted to explain why boron should become deficient as a
result of overlixuing.
Eaton and Wilcox (16) in studying boron fixation in
soils, recognize ionic exchange, molecular adsorption, and
chemical precipitation as three general mechanisms by which
boron may be removed from solution or fixed by the soil,
Liming or overllniing an acid soil increases the pH of
the soil. This increased pH Is in some manner responsible
for the reduced amount of available boron in the soil.
Naftel (31), for example, has treated a soil with lime in
amounts which would bring it to various stages of calcium
carbonate saturation. These amounts varied from 50% to
200%. The pH was increased from 5.9 to 7.95 in making these
calcium carbonate additions. Turnips and oats were planted
in a series of pots, some of which received no boron and
other 17.5 pounds borax per acre. The lime content was
varied as pointed out previously. Turnips seemed to be
particularly sensitive to a lack of boron, The pot having
150% calcium carbonate saturation without added boron
produced no turnips; yet, if borax was added at the rate
of 17.5 pounds per acre, high yields were obtained. Oats
responded in a similar fashion but to a lesser degree than
turnips. Naftel's work is summarized in Table 2.
5
TABI 2 - TBE EFFECT OF PERCENTAGE CALCIUM CARBONATEON pH AND CROP YIELDS
Yield YieldBoron (gms (grits)
Treatment pH added Turnips Oats
None 5.90 None 11.1 10.417.5#/A. 11.0 9.7
50% lime 6.35 None 6.4 10.0saturation 17.5#/A. 11.3 10.7
100% lime 7.77saturation
150% limesaturation
200% lime 7.95saturation
None17. 5#/A
0.00 9.312.2 11.7
This investigation shows that turnip yields are reduced
almost one-half when the pH of the soil is increased from
5.90 to 6.35, a condition brought about by bringing the soil
to 50% calcium carbonate saturation. Naftel discounts the
idea of the formation of insoluble borates; but advances in
its stead the idea of increased biological activity, and
hence a greater demand for boron when soils are limed. He
is supported in this contention by Bobko ( 3 ). It has been
shown by other investigators that boron deficiency occurs
more frequently on alkaline than on acid, soils ( 3O (27 )
(28 ).
6
Purvis and Hanna ( 36) have shown that
an overlimed Norfolk fine sandy loam retainedmore applied boron after leaching than did thesame soil in an unlimed. state, and this re-tained boron remained available to plants asevidenced by injury to subsequent crops.
After reviewing the foregoing work it is quite evident
that lime is responsible, in some manner, for a decreased
amount of available boron in the soil. In humid regions
the application of small amounts of lime to acid soils is
often responsible for the appearance of boron-deficiency
symptoms in crops which are later planted on the soils so
treated.
In Arizona, the majority of arable soils are caloar-
eous throughout the entire depth of their profile. Some
have been leached free of lime in the surface, and some are
very slightly acid in the extreme surface. The furrow
depth of soil, however, usually has a pH of 7.0 or higher.
If lime is the controlling factor in boron availability,
why are not the calcareous soils of Arizona deficient in
boron? The answer may lie in the probability of a wide
distribution of boron-containing minerals in the soil which
have not yet been removed by leaching; or, it may be that
sufficient boron is added to the soils by way of irrigation
waters.
Another related problem presents itself. lMhy do not
field crops which are irrigated with waters containing
7
high concentrations of boron show toxicity symptoms? A
partial answer to this question may be found in the fact
that many of the common field crops are tolerant of boron.
Or, again, it may be possible that lime, in some way, Is
causing a sequestration of boron so as to make it unavail-
able to plants.
These problems, and the general reaction of boron in
calcareous soil furnished the basis for the present investi-
gation.
S
SOIL USED FOR TEE EERINTAL PHASEOF THIS INVESTIGAT ION
The soils in the immediate vicinity of Tucson vary
widely in physical and chemical properties. Some are high-
ly oalcareous, while others have been leached almost free of
lime in the surface horizon. Since lime is considered to
be one of the prime factors in influencing the behavior of
boron in soils, its presence in varying quantity in the
soils selected for laboratory and greenhouse investigations
was one of the chief points considered. Six local soils
were chosen, and one or two acid soils from the East were
used occasionally. The soils involved in these studies were
as follows:
Laveen clay loamSuperstition sandPima clay loamTucson sandy loamMobave sandy clay loamPalos Verdes sandy loamWaverly clay loamDunkirk loam
The first six soils were secured locally. Some in-.
formation concerning them may be found in the Soil Survey
Report of the Tucson Area. Unfortunately this report does
not give the chemical properties of the soils in question;
hence Obenaical analyses have been made which proved useful
in explaining the behavior of boron in these soils. Table 3.
Lime Content of Soils
The lime content of the soils selected varied from a
little more than a trace to over 7 1/2%. The Palos Verdes
sandy loam and Mohave sandy clay loam, being most thoroughly
leached in the surface, contain the least amount of lime.
The Tucson sandy loam, which in reality is a calcareous
phase of Mohave, contains 1.4% of lime. The Laveen clay
loam, a highly caloareous soil commonly found in the Tucson
area, was found to contain 7.51% of calcium carbonate. The
Superstition sand, a sand from the Yuma mesa, was inter-
mediate in percentage of lime, as was the Pima clay loam, a
recent alluvial soil secured from the Santa Cruz bottoms.
TAI
3 - THE LThE CONTENT, HYDROGEN ION CONCENTRATION,
MD THE TOTAL
D SPECIFIC BUFFER CAPACITY
OF THE SOILS USED IN THIS INVESTIGATION
Soil
c0
aC
pllof
water suspension
Total
buffer
Capacity
Specific
buffer
Capacity
content Soil 1ater
1:1
Soil Water
idO
Laveen clay loan
7.51
7.70
8.60
l.72.
94.
Superstition sand
3.11
8.20
8.60
1.7
0.1+
7
Pim
a cl
ay lo
am2.
777.
1.iO
8.30
6.8
2.19
Tucson sandy loam
1.4.0
7.50
8.30
2.4.
0.69
Moh
ave
sand
y cl
ay lo
an 0
.18
7.70
8.20
1.0
0.33
PalosVerdes sandy
0.00
67.
858.
000.
30.09
11
These determinations were made by measuring the
carbon dioxide evolved from a given weight of soil when
treated with acid, and calculating the results to calcium
carbonate.
The pH values of these soils were determined on suspen-
sions of both the 1:1 and 1:10 soil:water ratios, the Inea-
surements being made with the Beckman pH meter. McGeorge
(22) has shown that differences in the hydrolysis of the
soil zeolite at different soil:water ratios is responsible
for differences in pH values obtained. The pH values found
in the table do not reflect the lime content of the soils,
confirming the findings of Buehrer (5 ). The Palos Verdes
sandy loam, for example, contains the least lime yet has
the highest pH on the 1:1 soil:water ratio. On the 1:10
soil:water ratio there is a parallel between lime content
and pH. The results are tabulated in Table 3.
Buff er Capacity
Closely related to the lime content and the pH of
soils are their buffer capacities. This determination
measures the ability of the soils to resist a H change.
in these particular soils,calcium carbonate is chiefly
responsible for their resistance to a downward change.
In Table 3 are also given their total and specific buff er
capacities. These determinations were made by the method
proposed by Pierre (35. They were made in the hope that
some correlation with their ability to fix boron in the
soil might be found.
Mechanical Analysis
Mechanical analysis determinations were made on all
of the soils by means of the Bouyoucos technique. Their
textures range from sands to clay loans; most of the soils
are of the heavier textures. It is of interest to note
that the Superstition sand and Palos Verdes sandy 1orn soils
are both light-textured soils. The Palos Verdes sandy loam
is without lime, and the Superstition sand has 3% of lime
as calcium carbonate. If the soils were related ruorpho-
logically, some rather interesting comparisons on the
effect of lime on boron fixation in the soil might be made.
The results of the mechanical analysis appear in Table 24..
TABLE 4. - 1VCHA.NICAL ANALYSIS OF SOILS
12
LaveenMohave
Palos VerdesSuperstitionPimaTucsonDirnkirkVaver1y
51.8 27.0 21.2 Clay loam61.8 16.0 22.2 Sandy clay
loam78.8 10.7 10.5 Sandy loam95.8 2.0 2.2 Sand35.6 44.0 20.4 Clay loam67.8 18.5 13.7 Sandy loam43.6 38.0 18.4 Loam33.6 4.4.0 22.4. Clay loam
Soil series % Sand % Silt % Clay Texture
Available boronefluxing Cold Water5 mm. Extraction
Soil (ppm) (ppm)
13
Boron Content of Soils
Most soils contain some boron. The form in which it
occurs is more important than the total amount present.
Boron occurring as tournialine is not readily available;
but when it occurs as a calcium or sodium salt, it is much
more readily soluble. Perhaps the most extensive work on
the determination of available boron in soils by chemical
methods has been done by Berger and Truog (1 ), who con-
cluded that available boron could best be determined by
ref luxing a soil with water for 5 minutes. Cold water or
carbon dioxide extraction removes less boron than the re-
fluxing procedure. In Table 5 the amount of boron extracted
from the various soils by different procedures is given.
TABLE 5 - BORON CONTENT OF SOIL3
Laveen clay loam 0.72 0.59Mohave sandy clay loam 0.37 0. 2L.Palos Verdes sandy loam 0.22 0.22Pia clay loam 7.13 3.60Superstition sand 0.05 0.064.Tucson sandy loam 0.27 0.24.
14.
Eaton (15) has shown that carbon dioxide extraction
yields a higher boron concentration than cold water extrac-
tion. He explains this on the basis of a lower pH in the
presence of carbon dioxide. The same effect was obtained
by the use of hydrochloric acid as the acidic reagent.
15
ANALYTICAL PRO C]3DURE
For a period of years the Agricultural Chemistry and
Soils Department of this Station has analyzed various water,
soil, and, plant samples for boron, using one of two methods
for each determination, and at times attempting to obtain
correlating results by using both methods for the analysis
of a single sample. The volumetric method, in which boron
is titrated as a monobasic acid in the presence of mannitol,
has been used extensively in this laboratory. At the
present time the titration end-point is determined by means
of a pH meter as suggested. by Foote (i6. Formerly the
Wilcox method was employed. This method is very similar
to that proposed by Foote, except that it involves the use
of calomel and quinhydrone electrodes and a galvanometer.
Routine water samples, soil extracts, and the ash of
plants are all analyzed by techniques developed from this
method. Results have shown that the method is readily
applicable to all samples where the boron content is rela-
tively large. It has been demonstrated that the method is
not particularly sensitive to interfering substances
other than carbon dioxide (both free and combined in acid
soluble form), which can easily be dispelled by boiling
16
in acid, solution, and phosphates which are precipitated by
means of lead nitrate, and therefore no longer interfere.
In carefully-eontx'olled experimental work involving
very small amounts of boron, it is desirable, if not
essential, to employ a micro-method for its estimation.
The Turmeric method proposed by Naftel (33) seemed to meet
the requirements of such a method, and was adopted for use
in this laboratory soon after it was published in 1939.
The procedure involved in this method is quoted from the
original article.
Procedure for Naftel Turmeric Method
Place an aliquot of a soil extract or plantash extract, containing from 0.5 to 8.0 microgramsof boron in a porcelain evaporating dish. Renderthe extract alkaline by adding 5 ml. or more ofa 0.10 N calcium hydroxide suspension and evapor-ate to dryness at full heat on a water bath.Remove the dish and allow to cool to room temper-ature6 at the same time cooling the water bathto 55 + 30 C. To the cooled residue add 1 ml.of the solution containing 80 ml. of a saturatedsolution of oxalic acid and 20 per cent hydro-chloric acid, and 2 ml. of a 0.10 per cent extractof curcumin or 1 per cent turmeric. Rotate thedish so that the reagents come into contact withall the residue and evaporate to dryness on thewater bath at 55° C. Continue heating for 30minutes at this temperature, then remove thedishes and allow to cool.
xtract the residue with 95 per cent ethyl alcohol
and transfer with a policeman to a filter or to a 15-mi.
centrifuge tube. filter and wash thoroughly with ethyl
17
alcohol, or throw down the solid phase with the centrifuge
(about 10 minutes at 1500 r.p.m.) and dilute the liquid
phase to constant volume with ethyl alcohol.
A calibration curve for a range of 0-10 micrograms
of boron is obtained by similarly preparing and analyzing
boron samples made up from a dilute standard boron solu-
tion, The sample containing no boron is placed in one
of the cells of a photelometer*, and with a green filter
in place the scale reading is adjusted to and maintained
at 100. Readings are then taken for the boron-containing
samples, and these readings are plotted against micro-
grams of boron present in the sample.
Reagents required:0.10 N suspension of caiclirni hydroxide.
Solution containing 20 ml. of concentratedhydrochloric acid and 80 ml. of a saturated sol-ution of oxalic acid prepared each day.
A 0.10 per cent curcuinin or 1.0 per centturmeric extract in 95% ethyl alcohol. Thelatter should be shaken occasionally. Filterand ue L.-6 hours after preparation. This ex-tract should be prepared daily.
Ethyl alcohol, 95 per cent.Standard solution of boric acid.
Naftel has developed the method in such a way that
an excess of the required reagents is employed; and he
gives tabular data to show that when this is done, wide
variations In volumes of the respective reagents seem to
A Cenco-Sheard-Sanford photelometer was used in allcolorometric boron determinations.
18
have little effect on the final results. The effect of other
ions on the boron determination was tested by Naftel by add-
ing definite amounts of boron to a water extract of
"fertile soil." Subsequent boron determinations proved
that the boron originally present in the soil and that
which had been added gave a sum equal to that found by
analysis. Naftel's data are shown in Table 6.
After the Naftel method had been used for several
months, discrepancies in the results prompted a re-exam-
ination of the procedure. A new set of reagents was
prepared and a new calibration curve drawn. Although this
new calibration curve appeared to have the same general
shape as that of the original one, its position had
shifted in such a way that results showed variations as
great as 100% in boron content when compared with read-
ings taken from the first curve. A series of such curves
was made by the same analyst and by different analysts
and, in spite of unusual precautions employed in experi-
mental manipulation, agreement in the results was found
to be rare.
In a search for the cause of the discrepancies, it
was decided that the turmerIc standard might be made up
permanently so as to eliminate a possible source of error
in preparing this solution daily, four hours before each
19
TABLE 6 - FECT OF IONS OTHER THAN BORON ON THEDETERMINATION OF BORON BY THE TtJRMIRIC
MTHOD*
From Naftel**Bo.o grams of Decatur clay extracted for 24. hours with
4.00 cc. of water.
SoilExtract**
AddedNo. (ml)
StandardBoron
Solutions(ml) (ppm)
BoronFound(ppm)
TotalBoronPresent(ppm)
Error
1-2 0 0 0 0 0
3-4. 25 0 0 0.010 0.010 0
5-6 25 1.0 0.04. 0.052 0.050 4.0
7-8 25 2.0 0.08 0.089 0.090 1.1
9-10 25 4.0 0.16 0.192 0.170 12.0
11-12 25 6.0 0.24 0.272 0.250 8.0
13-14 25 8.0 0.32 0.340 0.330 3.3
20
set of boron determinations was to be made. (Parenthe-
tically it must be emphasized at this point that Naftel
published tabular data which indicate that as long as an
excess of turmeric is employed, an additional small mere-
ment or decrement does not appreciably affect the results
of the determination.) Also, since turmeric solutions are
prepared from finely-ground roots, sampling errors and
the amount of the soluble material in the final filtered
suspension were thought to be responsible in part for the
discrepancies. Therefore, it seemed desirable to subject
this step of the analysis to closer examination. With this
in mind, a dilute turmeric indicator was prepared by the
following method to serve as a possible permanent standard:
2 grm of turmeric powder was placed in aflorence flash and 2 liters of 95% alcohol added.This suspension was boiled on the water bath for10 minutes and then filtered into a 2-liter vol-umetric flask. After cooling the filtrate toroom temperature, it was made up to volumewith 95% alcohol, mixed, transferred to a brownbottle, and stored in the dark.
In using the dilute turmeric solution, the Naftel pro-
cedure was followed identically, except for the fact that
a 5 ml. aliquot was employed for each sample instead of
the 2 ml. aliq,uot of the regular strength turmeric. In
order to test the stability of this solution, new calibra-
tion curves were made periodically. Two weeks elapsed
between the preparation of the first and last curves.
21
(See Table 7 and. Figure 1 for results.)
Note: * and. H are identical curves, and representedonly by x in Figure
* (1) July 21, 194.1** (2) July 23, 194.1
# (3) July 26, 194.1## (4.) August 6, 1941
TABLE 7 - DATA FOR CALIBRATION CURVES MADE OVER ATWO-WEEKS PERIOD, USING A PERMANENT,DILU2E TUThVJERIO INDICATOR
SampleNo.
Vol. ofippinBoron(ml)
Ant.ofBoron(mmg)
Photelometer Reading forCalibration Curve No.
1* 2** 3#00 0 0 100 100 100 100
0 0 0 100 100 100
1 0.5 0.5 88 88 88 88
2 1.0 1.0 80 78 78 80
3 2.0 2.0 63 62 62 63
4. 3.0 3.0 55 55 52 55
5 4.0 4.0 44. 4.6 4.6 4.4.
6 6.0 6.0 39 37 39 39
7 8.0 8.0 27 30 32 27
8 10.0 10.0 26 28 31 26
22
It was apparent from these results that the dilute
tunieric solution was more satisfactory than that which
was prepared from day to day.
After finding that by using this new tumeric solution
four successive calibration curves were sufficiently con-
cordantfor experimental work (see curves 1, 2, 3, 4,
FIgure 1), the method was employed to test the reagents
suspected to contain boron. Th reagents referred to were
previously employed in a sand culture experiment in which
desired macroscopic boron-deficiency symptoms failed to
appear during the,growth period (see Table 8). Sand
leachings, tap water, and distilled water were included in
the analysis.
Since the results indicate some kind of interference,
possibly that of the nitrate ion, they are not conclusive
for the absence of boron in any of the reagents where the
photelometer reading is more than 100 scale units. However,
if nitrate is the only interfering ion, sand leachings and
tap water both contain .05 p.p.m. boron. The magnesium
sulfate, calcium carbonate, and the distilled water deter-
minations all fall within the limit of experimental error
and can be classified as questionable. Tap water had been
run repeatedly in this laboratory by the Electroinetric
-Titration Method for boron, and found to give results
equivalent to those of distilled water, which is used for
(I) l07
z030
0100
Fig. 1. 90
No.
Sym
bol
(I)X0AX
8070
6050
4030
20P
HO
TE
LOM
ET
ER
RE
AD
ING
This curve and the
indicated points which delineate others ShO
W the reproducibility
of the calibration curve used in the Naftel
Turm
eric method for the determ
inationof boron.
*1
:1
Water extract,
TABL1
8
Comment
Prob
able
NO
3interfer eno e
Probable NO3
interference
Possible NO3
interference
Probable NO3
interference
Poss
ible
NO
3interference
Possible NO3
interference
Contains appreciable
boron
Contains appreciable
boron
Contains appreciable
boron
Questionable
RESULTS OF BORON ANJLYSES BY THE TURMERIC METHOD ON MPTERIALS TJSED
IN SAND CULTURE EXPERIMENT.
:
:Aliquot of:
:
reagent
:PhOtelO-.:
Micro-
grams
of
'esu
ing
:conc. of boron :
:Ifl the nutrient:
Sample:
No.
Reagents
:ConC. of:
Reagent:
tested
(ml)
:meter :borOri in-:
treading
:dicated
solution
(ppm)
1Calcium nitrate
.0025 molar
20
106,0
'1
2Potassium nitrate
40025
"20
105,0
3Magnesium sulphate
.001
"20
97.5
0 or
trace
trace?
Li.
Potassium di-hydrogen
phosphate
.0005
20
101.0
00
5Calcium carbonate
saturated
20
99,5
trace?
6Hoagland & i3royerts
solution
20
106.0
7Fe
rric
citrate
0.5%
20
101.0
'1
8Tartrate
0.5%
20
101.0
9*5
20
78.0
10.05
10
Tap
wat
er20
79.0
10.05
11
Tap water
20
78.0
10.
05
12Distilled water
20
98.0
0trace?
13
Contro.
20
100,0
00
2/
a blank in making the analysis. It was assumed, there-
fore, that, after a pre-treatment with hydrochloric acid,
the sea sand (a considerable amount of which was used in
the plant experiment) could he washed with tap water.
Also, as a matter of convenience, tap water was used in
watering germinating seeds as well as the very young
seedlings for a. jeriod of five days after planting. How-
ever, a turmeric test made subsequently on all reagents
indicates the presence of traces of boron in both sea
sand and tap water used in the experiment. (See Table 8).
If the presence of these amounts of boron can be con-
firmed, the probable reason for a lack of boron-deficiency
symptoms in the plants is at hand. Other sources or
greater amounts of boron in the reagents may be masked
by the interfering factors.
At this point it seemed essential to determine if
nitrates in particular are responsible for the interfer-
ence noted in the determinations reported in Table 8.
Data for this experiment are shown in Table 9. DeVardats
alloy was used in an attempt to reduce the nitrates to
ammonia and remove them from solution.
TABLE
9 -
NITRITE INTERFERENCE IN TI]E DILUTE TTJMERIC METHOD
Sample
No.
Vol. of
1 ppm
Boron
(rnl)
Boron
Taken
(rnmg)
Vol. of
1 ppm
Nitrogen
(ml)
Vol. of
Nitrogen
1 ppm N
Taken
(0)
(g)
(rn1
DeVarda's
Alloy
Photelometer
(+ or -)
Reading
10
00
00
-100
20
00
00
-100
30
00
00
+100
41
10
00
-77.5
51
10
00
-78
.56
11
00
0+
797
00
11
0-
105 approx.
80
01
10
+104
91
11
10
-90
10
11
11
0+
86
11
00
01
1-
100.5
12
00
01
1+
99.2
131
10
.11
-81
14
11
01
1+
81
Vol. of Vol. of
26
TABLE 10 - NITRATE INTERFERENCE WITH N.AFTEL 'STURMERIC METHOD FOR BORON
*Greefl filter used
Note: Boron was added as H3B03
Nitrate nitrogen was added as Ca (NO3)2
= .001 ing. = 1 microgram = 1 gamma
Sam-l.e.
No.
lppmBoronAdded(ml)
BoronAdded(nmig)
lppmNitrogenJdded(ml)
NitrogenAdded(rnnig}
Photelo-meterReading*
1 .0. 0 0 0 100
2 0 0 1 1 102
3 1 1 0 0 68
4. 1 1, 1 1 66.5
5 2 2 0 0 47.5
6 2 2 2 2 54.0
7 4. 4. 0 0 29.0
8 4. 4. 4. 4. 64.5
4. 4. 8 8 Very lightcolor
27
These results proved that either nitrate ion, potassium
ion, calcium ion, or a combination of these was responsible
for the interference with the tumeric determination. Since
calcium ion is used in excess in the regular determination,
it was assumed that one additional microgram of calcium ion
could not be detected and. was therefore not responsible.
Also, since the magnitude of the interference was approx-
irnately the same for both potassium nitrate and calcium
nitrate, the potassium ion was not considered as the causal
agent.
Table 10 shows that nitrate interferes with the regular
Naftel procedure; and when compared with Table 9 , that the
more dilute turmeric solution (0.1%) is more sensitive to
nitrate than the stronger (1.0%) solution. Since nitrates
are generally found in higher concentration in soils than
is boron, the turmeric method as proposed by Naftel is
definitely limited unless some provision is made to free the
sample being tested of its nitrate content.
Several attempts were made to discharge nitrates, but
all of these were unsuccessful. It was found that nitrate
interference could not be obviated by the use of a
stannous chloride, oxalic acid, hydrochloric acid mixture
(instead of the oxalic acid-hydrochloric acid solution of
the regular Naftel procedure), and that the effect of the
2
original presence of nitrates in the samples was still
apparent after ignition for two hours at llOO_12000 F. in
a muffle furnace. This result suggested the possible
additional interference by nitrites, but it was not veri-
fied.
Ignition to discharge nitrates is effectively used in
the J3erger-Truog Q,uinalizarin Method for the microdeter-
znination of boron; and it is thought that a longer ignition
might have corrected some of the interference in this pro-
cedure. However, considering all of the suggested possi-
bilities for error, it was decided that a new method should
be adopted. The method chosen involves the quinalizarin
reaction, and the procedure used in the present investiga-
tions is that given by DeTurk (3)4.).
The quinalizarIn method has quite recently been pro-
posed as a micro-method for the determination of boron (2.)..
Its possibilities for use in this work were accordingly in-
vestigated. It was found that nitrates interfere with the
óolor development in this method, too; but that a gentle
Ignition at llOO_12000 F. eliminates the interference.
Because of the precision and reproducibility of this method
It has been adopted as the standard micro-method for boron
determinations in this laboratory. (See Figure 4 for calibra-
tion curve.)
300
25fl
9590
8580
7570
PH
OT
ELO
ME
TE
RR
EA
DIN
GFi
g.L
Cal
ibra
tion
curv
e fo
r th
e O
ulna
lizar
iti M
etho
d of
det
eni1
nn, h
oroi
6560
55
29
Boron Fixation
Since the pH of soil colloids plays an important
part in their ability to adsorb various ions, it was de-
cided to determine the effect of pH on the adsorption of
boron by four stock soils. A series of bottles, each con-
taining 100 grams of soil and 500 ml. of 2.0 p.p.ra. boron,
received 0.0, 1.0, 5.0, 10.0, 25.0 and 50.0 nil, of N/b
hydrochloric acid, to give a wide spread in final pH
values. They were shaken 1 hour, and then filtered. Boron
determinations and pH measurements were made on the ex-
tract. The analytical results are recorded in Table 11.
These results have also been plotted in Figure 8.
In general, it might be said that boron fixation decreases
with a decrease in pH. However, at a pH of 7.Li. to 7.6,
each of the adsorption curves passes through a minimum.
Whether this is due to a pH effect on the colloid or to
calcium in solution is not evident. The next experiment
was designed to answer this question.
Calcium chloride in varying amounts was added to the
Palos Verdes sandy loam, and the whole shaken with a 2 p.
p.m. boron solution as in the previous experiment. The pH
was affected only 1.0 unit by the addition of calcium
chloride. The addition of calcium, however, induced
appreciable boron fixation. Above 300 p.p.m. of calcium
35
67
89
10
pH O
F SO
IL S
USP
EN
SIO
NFi
8T
he e
ffec
t of
hydr
ogen
ion
conc
entr
atio
n on
bor
on f
ixat
ion
in s
oils
0
025
.0.2
0
0.15
0l0
0 05
Sand
y C
lay
Ver
de S
andy
Cla
y L
oam
Sand
yLoa
m
Loa
mM
ohav
ePa
los
Lav
een
Supe
rstit
ioi
--4
'
TABLE 11
EFFECT OF DECREASING pH ON BORON FIXATION
5pH
values
Boron Fixed (mgs)
Boron :
(ppm)
Acid
added :
(ml)
:
Laveen :
clay
:
loam
;
Mohave
sandy
:
clay loam :
palos
Verdes
:
sandy loam :
Super..
stition
sand
:Palos
: Super-
:Laveen : Mohave : Verdes
:stition
00
8.14
79O
7.95
8.14
00
00
20
8.14
7.90
7.95
8.14
0.158
0.211
Ol1
420.
063
21
8.2
7.85
7,8,
8.2
0.1140
0.18
5--
-0.
066,
25
7.9
7.70
7.55
7.9
0.11
43--
-0.
071
0.0%
.
210
7.6
7,14
07.
145
7.6
0.138
0.121
0.19
80.
052
225
7.14
6.96
6.10
7.14
0.01
450.
126
0.08
70.
003
250
6.8
6.30
14.3
06.
80.
061
O..O1O
0.108
31
there was little effect on boron fixation by increasing the
amount of calcium in solutiOn. The results of this experi-
ment are given in the following Table.
TABLE 12- THE EFFECT OF CALCITJM IONON BORON FIXATION
The effect of pH values above 7.0 was not investigated.
The plan of the experiment was the same as for the two pre-
ceding experiments, except N/b sodium hydroxide was used
instead of hydrochloric acid or calcium. The results
appear in Table 13.
PH
BoronFixed(mg)
8.0 0
8.0 .128
7.5 166
7.1 .166
7.05 .156
7.0 .158
Ca BoronAdded Added
No. (ppm.) (mg)
1 o o
2 o 0.5
3 300 0.5
4. 570 0.5
5 1380 0.5
6 24.90 0.5
32
TABLE 13 EFFECT OF INCREASING pHON BORON FIXATION
Ml. Boron BoronN/b Added Fixed
No. NaOH (Eg) pH (mg)
Only a limited pH range was investigated here, but it
appears that boron fixation is greater at the higher pH
values. It appears to be a function of pH, as well as
soluble calcium concentration in the soil. This is con-
sistent with observed facts; namely, that boron is ren-
dered unavailable when a soil is overlimed.
1 0 0 7.95 0
2 0 .5 8.0 128
3 1 .5 8.1 .099
5 .5 8.3 .163
5 10 .5 8.6 .173
33
The Absorption of Boron by Phosphates
It has been shown by MoGeorge (22) that the formation
of double salts of phosphate such as carbonato-
apatite results in phosphate fixation in alkaline soils.
Smith (4.2) has developed a form of activated bone for
fluorine absorption from natural waters containing only
traces of natural fluorides. The reaction responsible for
the latter process, although not clearly understood, has
been shown by equilibrium experiments to be closely analo-
gous to solid-solution formation. Activation of the cal-
cineci bone is achieved by treatment with dilute sodium
hydroxide followed by dilute acid. After absorption of
fluorides, a similar treatment reactivates the bone. Since
the composition of bone is similar to the phosphates
ocurring in many natural soils and pH changes resulting
from fertilizer or amendment treatment are analogous to
the activation process, an experiment was conducted to
determine the relative absorption powers of activated bone
and rock phosphate. (See Table 14 and Figure 9 .)
The results clearly indicate that both activated bone
and rook phosphate are capable of absorbing considerable
boron from solution. A comparison shows that activated
bone is more powerful in this regard. It is interesting to
note also that activated bone absorbs more boron from
bIL
JDU
5O0
bo.o
30.0
20.0
10.0
-10.0
0
SActivated Bone
0Rook Phosphate
O-----O
Control Curve
100
20
3.0
50
-- -
60
7,0
BORON - FINAL CONCENTRATION IN SOLUTION PHASE (ppm)
FIg.
9.The relative fixation of boron by rook phosphate a
"act
ivat
ed"
bone
.9.0
10.0
34
solution than any of the soils so far tested. (Compare
Figure 5 and Figure 9 .) The process appears similar to
boron absorption by soils in that a fairly linear absorp-
tion curve is obtained when the eq.uilibrium concentrations
in the respective phases are plotted against each other.
Absorption increases as the concentration of boron in the
equilibrium solution increases.
That a similar mechanism is responsible for boron
fixation due to fertilizer treatment and addition of cer-
tain amendments such as lime to soils, or that the niechan-
jam is responsible for the retention of boron by soils
irrigated with toxic concentrations of boron irrigation
water, is not yet known. Evidence in the literature does
not seem to exclude the mechanism as a possible cause of
boron fixation ( 2]). However, it should be mentioned that
when fluorine is fixed by bone, it apparently is not so
easily released as is the boron from its fixation-complex
in soils ( 42a).
TABLE
i14.
FIXATION OF BORON BY ACTIVATED BONE AND
ROCK PHOSPHATE
Sa!1-
:
No.
Boron oonc.in solution
se
:___pha
Boron cone. in solid :
phase
:Final
conc.
(ppm)
pie
:Material
(10 gins.)
Original
:
(ppm)
:
Final
(ppm)
:
Original
:
(ppm)
Final
:
(ppm)
:
10
10.91
09.0
20
32.89
05.0
30
5L.
870
6.0
14.
010
9.80
010.0
1A
Rook
phosphate
10.91
9.0
2A
Rook
phosphate
32.79
10 0
3A
Rock
phosphate
5L
..67
16.0
LARock
phosphate
10
9.37
31.0
lB
Activated
bone
10.71
9.0
2B
Activated
bone
32,
14.6
5.0
3B
Activated
bone
514.28
6.0
143
Activated
bone
10
8.88
10.0
35
Leaching of Soils
There are numerous references in the literature (28,
30) whioh point to a decrease in the amount of boron avail-
able to the plant resulting from lime treatment and the
addition of other amendments and fertilizer materials.
Some authors contend that the boron is fixed in a less
available form in the soil due to such additions. Others
state that the plant metabolism is disturbed so that more
boron is required after such treatments (14). However,
there is no evidence to show that the fixation process
renders the boron permanently immobile (insoluble or un-
available). In this connection Scofield (41) holds that
where different soils are irrigated with the same boron-
containing irrigation water, the boron concentration builds
up in these soils in which the concentration of other salts
becomes excessive. Character and texture of the various
soil horizons, water table, amount of rainfall, and drainage
conditions in general are the major factors in this pro-
cess. Krugel, et al (21), experimenting with both acid and
alkaline soils, found that the boron added has a tendency
to be mobile under the influence of percolating waters,
notwithstanding the fact that all of the boron does not
leach out at once. They concluded that boron build-up in
a soil is not apt to occur where rainfall is adequate.
The results of the percolation and leaching experi-
ments obtained inths investigation confirm the idea that
See also ables 158. and. 15b.
3'6
boron is quite mobile in the soil, and that the fixation
is temporary, pending the application of boron-free
leaching in water. The extent of such temporary fixation
is greater in heavy soils than in those of light texture,
as shown by the slope of the fixation curves in Figures 5
and 6.* Although the leaching experiment (data for which
are set forth in Table l and plotted in Figure 7 is not
yet complete at this writing, the developing shape of the
curves indicates that the process becomes progressively
more nearly linear. If this character is studied more
thoroughly in future work, it may solve the question of
the fixation-complex within the soil. A straight line
parallel to the x-axis of such a graph would indicate
that the phenonien is one of simple solution. Confirmatory
data published. by Eaton (16), Table 16, show that within
the range of experimental error a solution curve does
finally result as leaching progresses. However, it is
realized that the results of leaching and percolation
experiments are not representative of true equilibria and,
in a final analysis, therefore should not be applied to
such an investigation. Rather, the true equilibrium rela-
tions should be brought out in an equilibrium experiment
devised. in such a way as to eliminate the usual srnpling
and salt-effect errors.
TABLE l5e
LEACHING EXPERIMENTJL DATA *
*These data are taken from Table and gives the conceni tion of boron in the soil at theend of the percolation experiment. The soils were not dried before the A' leaching treat-ment or between successive leaching treatmts.
Blank 200 ni. of h90 plus reagents.
Sam-ple
Soil
:Mgs. of boron!: Vol. of :Vol.:Kg, of soil at :percolate
: the start :titrated
z (ppm) :(nil)
of std.NaOH used
(ml)
:Vol. of std.Na1Ta0Hused for
blank (ml)
Boron conein.
percolate
: Mg. of boron :Mg. of Boron,Mg. of boron :Mg. of boronleached from leached/Kg :present/Kg of:present/Kg of125 g. of soil: of soil : soil before : soil after
:leaching(ppm):leaching (ppm)
1A' Superstition sand 11.97 50.0 1.1)4 0.9)4 1.99 0.50 14.00 11.97 7.972A' Pales Verdes sandy loam 18.22 50.0 1.96 1.76 3.73 0.93 7.L 15,22 10.783A' Piina clay loam 21.146 50.0 3.08 2.88 6.11 1.53 12. 2L 21.146 9.22
)4A' Mohave sandy loam 23.01 50.0 2.36 2,16 1.15 9.20 23.01 13.815A' Waverly clay loam 18.11 50.0 1.140 1,20 2. cLt 0 5.12 18.11 12.996A' Tucson sandy loam 23.63 50.0 2.62 2.)2 5.13 1.28 10.20 23.63 13.1437A' Laveen clay loam
1B' Superstition sand
11.12 50.0
50.01.7)40.25
1 ri..0.05
3.26
0.10
0,82
0.03
6.560.214
11 .12
7.97
-,
7.732B' Palos Verdes sandy loam 50.0 0.61 0.87 0.22 1.76 10.78 9.023B' Piina clay loam 50.0 i .1)4 0.9)4 1.99 0.50 9.22 5.22)4' Mohave sandy loam 50.0 0.90 0.70 1.148 0 .7 2.96 13.81 10.655B' Waverly clay loam 50.0 0.64 0.1i4 0.93 0.25 12.99 11.15
6W' Tucson sandy loam 50 0 0 66 0.148 1,02 0.26 2.08 13.143 10.357B' Laveen clay loam 50.0 0.72 0.52 II .LL) 0.28 2.2L1. 14.56 2.32
10' Superstition sand 100.0 0.3)4 0.1)4 0.15 0. 04 0.32 7.73 7.14120' Palos Verdes sandy loam 100.0 04)4 0,2L. o .25 0. c 9.02 ., .-, -30' Pima clay loam 100.0 1.06 0.86 0.91 0.23 1.8L 5.22 3.38)40' Mohave sandy losn 100 0 0 70 0.50 0.53 0.13 1.0)4 10.85 9.81
50' Waverly clay loam 100.0 C.6 0.56 C .59 0.15 1.20 11.15 9.956C' Tucson 3andy loam 100.0 0.58 0.38 c' .140 0.10 0.80 10.35 9.5570' Laveen clay loam 100 0 0.92 0.72 0.76 0.19 1.52 2.32 0.80
Percolatingsolutionorig.boron
conc,(ppm)
Vol. of Dilutionpercolateevaporate d
ignited(ml)
volume Volume Microgramsafter used for Photo- of bonignition analysis lometer found/
(ml) (ml) Reading aliquot
Cone, ofboron inpercolate
(ppm)
Mg. of boronfixed/kg.of soil
(ppm)
Total mgs.boron fixed/kg, of
eac} soil
(ppm)
1 A Superstition sand 0.5 40.0 8,0 5.0 75.0 10.5 0.142 0.32 **0.05 0.37 11.922 A Paics Verdes sandy loam 0.5 40.0 8,0 5.0 82.0 6.3 0.25 0.96 **Q.22 1,18 18 003 A14 A
Pima clay loanMohave sandy clay loam
0.50.5
40.0140.0
8.08.0
2.05.0
60.086.0
26.014.4
2.600.18
8.1401.28
**7.13**O.37 1.65
114.3323.01 c-Io
5 A Waverly clay loam 0.5 50.0 8.0 5.0 76.5 9.5 0.36 0.56 **O.l9 0.75 17.92 C)'C)
6 A
7 ATucson sandy loamLaveen clay loam
0.50.5
50.050 0
8.08.0
5.05.0
814.081.5
5.36.6
0.210.26
1.120.96
*.O.27**O.72
1.391.68
23.3610.40
00C) S
oU2 0
1 B Superstition sand 1.0 50 0 10.0 5.0 66.0 18.0 0.72 1.12 0.37 1.1490C) 0
2 B Palos Verdes sandy loan 1.0 50.0 10.0 5.0 68.5 15.6 0.62 1.52 1.18 2.70 -zf 0N--Ps3 B Pima clay loan 1.0 50 0 30.0 5.0 83.5 5.6 0.67 1.28 1.28 U?
C -I 014 B Mohave sandy clay loam 1.0 50.0 10.0 5.0 72.0 12.7 0.51 1.92 1.65 3.57 0 rI
- 4.) C)
5 B6 B
Waverly clay loanTucson sandy loam
1.01.0
50.050.0
10.010.0
5.05.0
68.067.0
16.117.0
0.650.68
1.361.28
0.751.39
2.112.67
I r' 4..r4
o o 0 C)cn'OL) -,-) C) 4'c40
-. -P4)r-Vol.of Corrected C) C)o C) 5 ) .Qr C) 00
Vol. of std. vol. of -Pr1 .-I 4-'C)0-.-4 -HO
percolate Na0 I'a0HC) C) .U: U? -p
C) -H (U U)
titrated used Used (U C) 0 C) 4-'. . U) -1 0 L C)
(ml) (ml) (ml) C) - 4.) I 0-p 0o4J7 B1 C2 C
Laveen clay loamSuperstition sendPalos Verdes sandy loam
1.02.02.00
200.0200.0200 00
1.1483.5143.10
0 681.771.514
0.681.77
1.280.981,814.
1.681.1492.70
2.962.37
Q CoC) U) p.c1ti .,-i d 00 G rI C)
p. C) -4 U1,-1 i'1 :i 0 -H ) C)
3 C Pima clay loam 2 00 200.0 2.78 1.37 1.37 2.48 1.28 3.76 0-HO 0-.--j-Po CpQr4U)14 C Mohave sandy clay loam 2.0 200.0 2.80 1.38 1.38 2.48 3.57 6.05 C)
5 C Waverly clay loam 2.0 200 0 3.22 1.60 1.60 1.60 2.11 3.71 ..-1 o i0 c- U) 0 C) ..
6 C Tucson sandy loam 2.0 200.0 3.02 1.50 1.50 2.00 2.67 14.67 ., C) 0 Q 0 $. r1 .HC) C)
7 C Laveen clay loam 2.0 200 0 2.98 2.78 1.147 2.08 2.96 5.014 v-P.m C)-HU(Up.)C) U)'c
1 D Superstition sand 5.0 200.0 8.34 *8.14 4.1)4 3.L1)4 2.37 5.81 C) 0 S-U) hDC)--'
2 D Palos Verdes sandy loam 5.0 200.0 7.78 *7.58 14.05 3.76 4.54 8,30 0 4) IC)o C) 0-C) . C) U) r1 ,
3 D Piina clay loam 5 00 200.0 6.14 *6.21 3.29 6.80 3.76 10.56 0 04 .4 C) ,) -H C) ) ) -H p.4.) 0DC) os--P
14 D Mohave sandy clay loam 5.00 200.0 7.10 *6.90 3.08 7.68 6.05 13.73 -.44-) C)-4 C)
5 D Waverly clay loam 5.00 200.0 7.06 *6,86 3.65 5.36 3.71 9.07 00-Hc-40 ,-4 -P 0-4 4)06 D Tucson sandy loam 5.00 200.0 7.12 *6.92 3.56 9.76 14.67 14.43 C) -4Q) -U)C)-4...c-4 00 01 .-( C)
7 D Laveen clay loam 5 00 200.0 3.48 3.28 3.48 6.08 5.014. 11.12 O,U) 0C) C)U) Q
1 E Superstition sand 10.00 100.0 8.140 *8.20 8.46 6.16 5.81 11.97 C) -U 0 0 0 .4.) -H0 C)Jp. (U .-C)
2 E3 E
Palos Verdes sandy loamPima clay loam
10.00
10.00
100.0100.0
7.987.2)4
*7.78*7.04
7.527.27
9.9210.90
8.3010.56
18.2221.46
,-i-HC)$0j.-I ..-(U-PrHi0p.
14 E Mohave sandy clay loan 10 00 100,0 7.32 *7.12 7.67 9.28 13.73 23.015 E6 E
Waverly clay loamTucson sandy loam
10.0010.00
100.0100.0
7.1487.L
*7.28*7.214
7.747.70
9.014.9.20
9.0714.43
18.1123.63
0-PCiC) C) C)
C-i <-4-' > 4.)* *0 0 0 0
7 E Laveen clay loan 10.0Z -
38TABLE 15a
PERCOLATION EJERIMENTAL DATA
Mg. of boron/ Mg. boron/kg. of soil kg. of soil
after eachbefore eachsucces sive successivepercolation percolation
(ppm) (ppm)
Sam.pieNo. Soil
l60
1140
12.0
10.0
60
Ll.0
2.0
-2.0
/
/
/
////7
/V//,/ /-,,/ ,/
///7,-
Superstition Sandy LoamPales Verde Sandy LoamVo}iave Sandy Clay LoamTucson Sandy Loam7aver1y Clay LoamPima Clay LoamLaveen Clay Loam
lO 2.0 3.0 L.o 50 6.0 70EQUILIBRIUM BORON C0NCENTAT1ON ii SUPRNATAT SCUTIG (ppm)
Fi 5 The amount of boron tfixed 'oy soil when shaken with OC O,iO? 5.0, and 10O0 pm boron soLutions0
19.0
18.0
2L0
22 0
2000
1800
16.
fJii40
12 0
10.0
8.0
6.0
402.0
1.02.0
3.04.0
5.06.0
7..08,0
90 10.0B
0N IN
CR
IOIW
AL
sai.,uio(ppm
)
A
/7
boron in a soilS
Brel*t.&
to te
-o
Superstition Sandy Loam
Palos Verde Sandy £oSrn
Mohave Sandy C
lay Loai
Tucson Sandy L
oamW
averly Clay L
oam
Pima C
lay Loam
Lavoen C
lay Loam
and concentrati on of per,olating
22:\:\2008,0
-.40
o14.0
12.0
0i-I
8O
o£.14.0
20
NN
NN
NN
N
100
Yig 7.
\NN
0.-
--
Superstition Sandy Loam
Palos Verde Sandy L
oamV
ohave Sandy Clay L
oamT
ucson Sandy Loam
Waverly C
lay Loam
Fima C
lay Loam
Laveen C
lay Loam
-. _. -. --004:.
700800
600200
3001400
500T
OT
AL
VO
LT
ThtE
OF L
AC
ING
WA
T(m
l)
boron remaining in. a sU
. after 1eahin with diti11d.w
*ter.:
.
39
*A.D. Air dry
TABLE 15b
EQUILIBPITJ1 E)ERINT DATA
Sam-
pleNo.
: Mgms.:Vol. of super- :Made up to: Volume Axnount of : Mgms. :of Boron
Original :natant sol.eva_:vol. after; for : Phote - :Poron found/ :recovered/:added/Kg:sol. Boron:pOrated and ig- ignition :analTsis: lon'eter aliquot : :Kg of A.]Yt:cf A.D.
Soil conc.(ppm): nited (nil) (ml): (nü) reading :(micro_grams):Factor:soii. (ppm):soil(ppm)
"gms.:of Boronfixed/g
A.D.:soil(ppm)
:Tot.ingms. of :Firal cone.::Boron present/: :Cf Boron in:Kg of soil Super-:&fter shaking natant
(ppm) :Factorl solution
1A Superstition sand 0.0 )4o.o 8.0 5.0 97.0 0.14 0.16 o.o6L. 0 -0.06 25.0 0.0162A3A
Palos Verdes sandy loamPima clay loam
0.00.0
140.0
140.08.08.0
5.01.0
93,586.0
1.1414.5
0.160.80
0.2203.600
00
-0.22
-3.60
25.05.0
0.0560.900
5A
6A
Mohave sandy clay loamWaverly clay loamTucson sandy loam
0.00.00.0
Lj.0.0
)4o.o
L1o.o
8.08.080
5.05.05.0
93.09)4.0
93.0
1.51.21.5
0.160.160.16
0.2)400.190
0.2)40
0
0
0
-0.24-0.19-0.2)4
25.025.025.0
0.060
0.0)48
0.0607AlB2B
rlB
Laveen clay loamSuperstition sandPalos Verdes sandy loamPirna clay loamMohave sandy clay loam
0.50.50.50.50.5
140.0
140.0
140.0140,0
)4Q.0
8.010.010.0
140.0140.0
5.05.05.05.05.0
87.582.085.082.087.5
3.76.35,0
6.33.7
3.160.200.200.800.20
0.5001.2601.000
5.0)40
0,7)40
02.02.02.02.0
-0.590.7141.00
-3.0141.26
0.80.1.220.561.50
25.020.020.05.020.0
0.1)48
0.3150.2501.2600.160
5B6B
Waverly clay loamTucson sandy loam
0.50.5
)4o.o140.0
140.0L1.o.o
5.05.0
82.086.0
6.314.5
0.200.20
1.2600.900
2.02.0
0.7)4
1 .10
0.931,3)4
20.020.0
0.3150.225
7E Laveen clay loam 0.5 )4o.o 15.0 5.0 88.5 3.2 0.30 0.960 2.0 1.0)4 1.63 13.3 0.Pt10.602ic Superstition sand 1.0 )4o.o 15.0 5.0 79.0 8.0 0.30 2.1400 1 60 1.66 13.3
2C Palos Verdes sandy loam 1.0 140.0 15.0 5.0 79.0 8.0 0.30 2.L00 1.60 1.82 13.3 0.6023C Pinia clay loam 1.0 )4o.o )4o.o 3.0 93.0 l.5 1.33 2.000 14.0 2.00 5.60 3.0 0.500)4c Mohave sandy clay loam 1.0 140.0 15.0 5.0 61.0 2)4.14 0.30 7.320 14.0 -3.32 -3.08 13.3 1.8305C
60
Waverly clay loamTucson sandy loam
1.01.0
)4o.o
)4o.o15.015.0
5.05.0
87.076.0
3.99.9
0.300.30
1.170
2.970
2.83
1.03
3.021.27
13.313.3
0.293
0.7)4)47C Laveen clay loam 1.0 )4o.o 20.0 5.0 8L.o 5.14 0.140 2.160 14.0 1.8)4 2.143 10.0 o.)4o1D Superstition sand 2.0 20.0 15.0 5.0 7L4..0 11.2 0.60 6.720 8.0 1 .28 1.3)4 6.67 1.6802D Palos Verdes sandy loam 2.0 20.0 15.0 5.0 78.0 8.5 0.60 5.100 8.0 2.90 3.12 6.67 1.2703D Pima clay loam 2.0 20.0 140.0 3.0 88.5 3.2 2.66 8.510 8.0 -0.51 3.09 1.50 2.130
Mohave sandy clay loam 2.0 20.0 15.0 5.0 82.0 6.3 0.60 3.780 8.0 14.22 6.67 0.9)405D6D
Waverly clay loamTucson sandy loam
2.02.0
20.020.0
15.015.0
5.05.0
75.580.5
10.27.1
0.600.60
6.720Li..260
8.08.0
1.28
3.714
1.147
3.986.676.67
1.5301.060
7DlB
Laveen clay loamSuperstition sand
2.05.0
20.010.0
20.015.0
5.05.0
8)4.071.0
5.14
13,14
0.801.20
14.320
16.1006.0
20.03.673.90
14.27
3.96
5,00
3.33
1.080
14.0202E Palos Verdes sandy loam 5.0 10.0 15.0 5.0 75.0 10.05 1.20 12.100 20.0 '-71. 8.12 3.33 3.0203E Pim.a clay loam 5.0 10..0 140.0 3.0 90.0 2,70 5.33 14.1400 20.0 5 60 9.20 0.75 3.600
Mohave sandy clay loam 5.0 10.0 15.0 5.0 77.0 9.20 1.20 11.000 20.0 9.00 9.2)4 3.33 2.7605E6E
Waverly clay loamTucson sandy loam
5.05.0
10.010.0
15.015.0
5.05.0
73.076.0
12.009.90
1.201.20
1LJ.4.0011.900
20.020.0
5.608.10
5.798.3)4
3.333.33
3.600
2.9707E Laveen clay loam 5.0 10.0 20.0 5.0 80.0 7.140 1.60 11.800 20.0 8.20 8.79 2.50 2.960iF Superstition sand 10.0 5.0 25.0 5.0 79.0 8.00 )4.00 32.000 )4o.o 8 00 8.06 1.00 6.0002F Palos Verdes sandy loam 10.0 5.0 25.0 5.0 81.5 6.60 14.00 26.1400 )4o.o 1)4.60 1)4.70 1.00 6.6003F Pirna clay loam 10.0 5.0 50.0 3.0 92.5 1.70 13.33 22.O0 )4o.o 17.30 20.90 0.30 5.67014F Mohave sandy clay loam 10.0 5.0 25.0 5.0 8)4.0 5.140 4.00 21.600 )4o.o 18,140 18.60 1.00 5.14005F Waverly clay loam 10.0 5.0 25.0 5.0 78.0 6.50 14.00 3)4.000 140.0 6,00 6.19 1.00 8.5006F Tucson sandy loam 10.0 5.0 25.0 5.0 81.5 6.60 14.00 26.L00 140.0 13.60 13.80 1.00 6.6007F Laveen clay loam 10.0 5.0 25.0 3.0 87.0 3.90 6.67 26.000 140.0 lL1. .00 1)4.60 0.60 6.500
40
TABLE 16 - THE RELEASE OF BORON DURING LEACHING WITH
*Table taken from a publication by Eaton andWilcox (16).
SUCCESSIVE, EQUAL VOLU1VEIS OF BORON-FREESOLUUIONS*
Trial No. Soil No. 1 Soil No. 2
1 0.87 0.892 0.53 0.663 0.33 0.604 0.25 0.385 0.10 0.276 0.114 0.307 0.14 0.228 0.08 0.159 0.10 0.15
10 0.08 0.15U 0.06 0.1712 0.05 0.1413 0.07 0.1214 0.04 0.1215 0.05 0.16
41
PLANT XEERThNT
The literature abounds in reference to boron as
an essential element for plant growth. (4. ) (6 ). Other
investigators have shown very definitely that boron is
exreme1y toxic to plants if present in the nutrient sol-
ution in amounts slightly higher than optimum (20), (1+1),
(4.5). The manner in which boron affects plants which were
grown in sand culture under various treatments forms the
basis for this part of the investigation. Lack of suit-
able equipment and the uncertainty of being able to inter-
pret results of water cultures in terms of field condi-
tions made it seem more desirable to limit the plant
experiments to sand cultures. It is realized that such
cultures involve more chances for contamination than
solution cultures. $ince Scofield, Wilcox, and Blair (42)
have shown that the quantity of boron contained as mi-
purities in the reagent salts used for culture solution
was insufficient to support normal growth of sunflower
seedlings, such reagents were employed in this work.
With the latter assurance in mind, a sand culture
experiment was started. It was planned to determine the
effect of lime on boron intake when this element was
42
present in both toxic and deficiency amounts. Duplicate
pots containing sunflower and cotton were used. Although
apparent boron-deficiency symptoms were reflected in the
yields, the external deficiency symptoms were lacking.
In order to explain the lack of positive deficiency
symptoms, analyses were made on the constituents of the
nutrient solution, and on the sea sand used in the experi-
ment.
The analyses were made by the quinalizarin method
on samples, the boron of which had been separated by dis-
tillation as methyl borate. In the case of sea sand, 25
grams or sample was refluxed with 40 ml. of distilled
water. Boron was determined on this extract by the quin-
alizarine method. The results of the tests for impur-
ities in the component parts of the sand. cultures are given
in Table 17.
The nutrient solution supplied 27.2 micrograms of
boron to each pot, and the sand only 0.3 micrograms. The
sand might be considered to have been washed satisfac-
torily, but appreciable quantities of boron were added
to the pots by way of the nutrient solution and calcium
carbonate additions. The high lime pots received 65
micrograms of boron as impurities, which may explain why
boron deficiencies as determined by yield were not more
pronounced.
Substance
Ca003
(0a003
( (CaCO3
(MsO
(K1o
3(Ca(NO3)2
Washed
sea
sand
F err i
C
citrate
Total
TA
BLE
17
-TE
EBORON
CONTENT OF TUE COMPONENT PARTS
OF
SAN
D C
UL
TU
RE
S
O.P.
Merck & Co.Inc.)
Reagent
J.T. Baker
Chem. Co.
)0
Reagent
Merck & Co.Inc.)
teagent
Del Monte
Merck & Co.Inc.
)
0).
80.
24.
017
.68.
8
: Total
:
Wt.
of
:Boron in:Boron
Orig.
:in.
:Sam
ple
:sample
):
(iw
ing)
:ing/
kg
27.2
3.20
:Boron in;Estiinatod weight
:10 L. of:of boron Added to
:Nutrso- :each Pot from
lution :These Sources (mnig)
(mg)
:2-6
7-11
12-16 17-21
Ol.61.
16.4.
6Q
not used
ifif
27.2
27.2
0.30
0.50
27.2
9.30
0.50
272
0.30
0.50
7.2
0.30
0.50
28.0
29.
64. 4
4..L
1.93
.0
Reagent
games Good,Inc.
014
.0.
56
Reagent
General Chem.
Co.
20
552.
20Reagent
ifif
030
1.20
Boron
Added
Grade
Manufacturer
TA
BL
E 1
7aPO
SSIB
LE
BO
RO
N C
ON
CE
NT
RA
TIO
NS
IN O
VE
N-D
RY
PL
AN
T M
AT
ER
IAL
RE
SUL
TIN
G F
RO
M A
BSO
RPT
ION
OF
BO
RO
N A
DD
ED
AS
C O
NT
AIV
IIN
AN
T I
N S
AN
D C
tJL
TFJ
RE
MA
TE
RIA
LS
*
App
rox.
Vol
. of
Poss
ible
Bor
onV
ol. o
f5%
Fer
rie
Con
tent
of
Ove
n-Po
tG
ram
s of
Per
cent
Nut
rien
tC
itrat
eD
ry P
lant
No.
LiE
le/P
otL
ime
used
(L
)(m
l)M
ater
ial (
ppm
)
is a
ssum
ed th
at a
ll th
e co
ntam
inan
t bor
on is
abs
orbe
d by
1 g
ram
of o
ven-
dry
plan
t rui
ater
ial.
2-6
00
1010
02.
O
7-11
2,9
0.25
1010
029
.6
12-1
629
.14.
2.50
1010
044
.4
17-2
111
7.5
10.0
1010
093
.0
:Boron Cone.:
:
)4.375L4.
3.9291
Averageyield(grams)
3.7638
1.0626
3.7985
14.1811
14.1765
14.1438)4
TABLE 18
DATA FOR THE SAND CULTURE PLANT EPERIMENTS - SUNFLCWER
Average : Iron (Fe) 2
PPM Boron Boron : Calcium : Average Phosphorous Average conc. in Average Ca/B ratio Averagein plant(mg/Kg)
COflC. plant : Calciujil(ppm) : (%) 2 (%)
(P) inplant (%)
: Phosphorous(P) ()
plant
(ppm)
Ironic.l
in plant(ppm/ppm)
Ca/B2 ratio
159.0 3.77 0.1498 207 23738.1 2.93 0.239 173 769714.7 2.63 0.196 100 35278.8 106.0 2.75 2.63 0.219 0.215 116 1)42 3)49 359
110.0 2.143 0 .2114 127 221229.0 2.143 0.207 9)4 106
3)4.1 3.146 0.209 103 1015514.3 3.5)4 0.206 73 65267.3 92.3 3.87 3.61 0.235 0.206 108 90 575 56183.7 3.21 0.190 82 38)4
220 3.99 0.190 82 1058.0 3.78 0.203 88 65252.6 0.191 71 78187.7 85.2 3.23 3.59 0.199 0.182 76 81 368 147193.9 3.52 0.170 87 375
186 0 3 30 0.1147 79 177- 6 5.L) 7 0.207 90 63270.14 14.18 0.166 914 59)4&; .9 106.0 14.145 0.1)47 0.171 93 92 637 51892.14 89 0.170 91 529
213 0 LI .21 O 166 90 198
38.1 2.93 0.239 173 769314.1 5)4.2 3.146 3.91 0.209 0.215 103 1114 1015 76758.0 3.78 0.203 68 65286.6 5.147 0.207 90 6327)4.7 2.63 0.196 100 3525)4.3 63.0 3.5)4 3.62 0.206 0.19C 73 35 652 59552.6 14.11 0.191 71 78170.14 14,' e 0 166 9)4 5914
78.8 2.75 0.219 116 3)49
67.3 z 075.9 3.58 0.235 0.200 106 99 575 148237.7 3.23 0.199 78 36869.9 14.145 0.1)47 93 637
110.14 2.143 0.2114 127 22183.7 95.0 3.21 3.51 0.190 0.186 32 97 36L1 37793.9 3.52 0.170 87 37592.14 0 170 91
229.0 2.143 0.207 9L 106222.0 213.0 3.99 0.190 0.172 82 86 180 165186.0 3.30 0 .1147 79 177213.0 Li .21 0 166 90 198
Pot Lime :lfl nutrients Oven-dryNo. : added solution
: yield(%) : (ppm) (grams)
1 0 0 0.96870 0 3 .1197
3 0 0.25 14.001140 0.50 3 .9520
5 0 0.10 3 .93506 0 5.00 p.81077 0.25 0 14. 85938 0.25 0 25 14.37509 0.25 0.50 14.27143
10 0.25 1.00 14.857211 0.25 5.00 3 .921212 2.50 0 14.098313 2.50 0.25 14.51501L1. 2.50 0.50 14.618815 2.50 1.00 14. 57 7716 2.50 5.00 14.067017 10.00 0 J16718 10.00 0.25 3.832819 10.00 0.50 3.860920 10.00 1.00 14.383721 10.00 5.00 IkLI5l)4
2 0 0 3 .11977 0.25 0 14.8593
12 2.50 0 14.098317 10.00 0 3.1167
3 0 0.25 14.001148 0.25 0.25 14 .3750
13 2.50 0.25 14.515018 10.00 0.25 3.8328
14 0 0.50 3 .95209 0.25 0.50 14.27143
114 2.50 0.50 14.618519 10.00 0.50 3.8609
5 0 1.00 3 .935010 0.25 1.00 14. 857215 2.50 1.00 14. 577720 10.00 1.00 14.3837
6 0 5 00 3.810711 0.25 5.00 3.921216 2.50 5.00 14.067021 10.00 5.00 14 .145114
45
TABLE 19
DATA FOR THE SAND CtJLTURE PLA1T TSI!NTS - COTTON
:Pot :No. :
:BOrOfl COnC,:Lime in nutrient:
acded : solution(%) : (ppm) :
Oven-dry :yield :
(grams) :
Average :yield :
(grains)
PPM Boronin plant(mg/Kg)
:Average :
: Boron :
cone. :
: (ppm) :
Calcium : Averagein plant: Calcium
(%) : (%)
:Iron (Fe) :Phosphorus : Average : cone. in :(P) in Phosphorus plant :
: plant (%) : () (%) (ppm)
Average Ca/B ratio :
iron : in plant :(%) (ppm/ppm) :
AverageCa/Bratio
1 0 0 1.3124 50.0 2.53 0.578 183 506
2 0 2.5074 19.0 227 cJ.295 96 1195
34
00
0.250.50
3.30602.7314 2.8600
19.727.5 45.2
2,112J44 2.39
0.2590.317 0.311
97117 122
1071887 762
56
00
1.05.0
2,86912.8860
66.293.6
2.552.56
0.3)4O.3L2
160139
38527L.
76
0.250.25
00.25
4.00423.5334
15.740.5
2.962.90
0.2)490.240
10091
1583716
910
0.250.25
0.501.0
3.29613.1976
3.4269 81.971.3
67.1 3.243.22
3.16 0.2790.265
0.265 8588
91 396452
686
11 0.25 5.0 3.1034 123.0 3.46 0,290 90 281
2.5 0 5.5350 55.5 2.98 0.279 102 55413 2.5 0.25 3,4945 65.3 3.68 0.284 103
1.Li. 2.5 0.50 2.7213 2,9862 83.8 84.5 3.67 3.43 0.279 0.288 103 102 438 )449
15 2.5 1.0 2.5174 75.5 3.44 0.288 95 456
16 2.5 5.0 2.66L1.8 i)).o 3.37 0.308 105 23417 10.0 0 2.4355 Li.6.4 5.80 0.2L& 115 519
18 10.0 0.25 2.8695 72.8 3.70 0.270 98 508
19 10.0 0.50 2.9138 2.5695 78.1 86.1 3.92 4.00 0.246 0.274 96 104 502 518
20 10.0 1.0 2.4750 92.1 4.00 0.299 97 43421 10.0 5.0 2.1488 141.0 4.58 0.309 112 325
2 0 0 2.5074 19.0 2.27 0.295 96 1195
7 0.25 0 4.0042 3.1200 18.7 30.2 2.96 3.00 0.249 0.267 100 103 1583 1038
12 2.5 0 3.5330 53.8 2.98 0.279 102 55)4
17 10.00 0 2.4355 46.4 3.80 0.246 115 819
5 0 0.25 3.3060 19.7 2,11 0.259 97 1071
8 0.25 0.25 3.5334 3.3009 40.5 49.6 2.90 3.10 0.2)40 0.263 91 97 716 715
13 2.50 0.25 3.4945 65.3 3.68 0.284 103 564
18 10.00 0.25 2.8695 72.8 3.70 0.270 98 508
4 0 0.50 2.7314 27.5 2.LiLi. 0.517 117100
587396 556
9 0.25 0.50 3.2961 2.9169 81.9 67.8 3.24 3.32 0.279 0.280 85438
1419
2.5010.00
0.500.50
2.72132.9188
83.878.1
3673.92
0.2790.246
10396 502
5 0 1,0 2.8691 66.2 2.55 0.314 160 385432
10 0.25 1.0 3.1976 2.7648 71.3 76.3 3.22 3.30 0.265 0.298 88 110 452
15 2.50 1.0 2.5174 75.5 3.44 0.288 95 456
20 10,00 1.0 2.4750 92.1 4.00 0.299 97 43)4
6 0 5.0 2.8860 93.6 2.56 0.342 139 274
11 0.25 5.0 3.1034 2.7008 123.0 125.0 3.46 3.49 0.290 0.312 90 112 281 279
16 2.50 5.0 2.6648 iJ4.o 3.37 0.308 105 234
21 10.00 5.0 2.1488 1)4.0 4.58 0.309 112 325
4.6
Interpretation of the Sand Culture ResultsThe general plan of the sand culture experiment, as
well as the accumulated experimental data, are given inTables 18 and 19. Yields were determined on the oven-dry
basis after eight weeks of growth, and all subsequentcalculations were made on this basis.
r2he results show that boron, as well as calcium,
absorption by the plant is increased by increasing therespective concentrations of these elements within the
culture medium. (See Tables 18 and 19) As progressively
Increasing amounts of these elements are added to the
medium, the optimum concentration levens are eventually
exceeded, and toxià concentrations are built up which are
reflected in decreased total absorption and decreased
yield. Since it is well known that such relations hold
for most or the nutrient elements, these results are
not surprising.It has recently been demonstrated by Drake, et al (14)
that the adequacy of boron concentration within plant
tissue can be interpreted advantageously in terms of the
oalciuin:bOrOfl ratio (ppm. calciumppni. boron on the oven-
dry basis) within the plant tissue. They have used. the
ratio as one of the indications of the frequent def 1-
cien.cy symptoms which result from overliining soils in which
47
boron had been deficient previously. Definite limiting
and optimum ratios were set up on the basis of their re-.
suits. The authors make the following statement:
The growth of Turkish tobacco grown on aNorfolk sand in greenhouse pots appeared normalwhen the calcium-boron ratio in the plants didnot exceed 1,340:1. A calcium-boron ratio of1,500:1 in the plants was correlated withsevere boron starvation symptoms.
It has been found in this work that the ealcium:boron
ratio is an important plant relationship; but that the
limiting values as set up by Drake, et al are not applica-
ble to the plants used in this experiment.
Results with Sunflower as the Test Plant
In addition to the numerical data given in Table 18,
many of the results have been treated graphically in the
accompanying figures, the interpretation in most cases
being made on the basis of the calcium:boron ratio. Since
the relationships considered have been found to be com-
plex, the graphs are correspondingly complex and require
study within themselves and in relation to the other fig-
ures before the results can be interpreted. Also, the
graphical treatments of the cotton and. sunflower results
must be considered separately, although similarity of
curve inflection and slope will be noticed in many cases.
-.-.-
.25'N
N
500600
700C
a:BR
AT
tO(p.pLm
/p.p.m) /
800900
Fig.1,.5
The affect of over-lim
ing on yield of sunflowers
at various concentrations of boron in
1000
4..6
4-4
4
2.5
%-,.."
I-
II
N
II2.54
04.O
o.
3.6
3-4
32
5,4
SU
NF
LOW
ER
5.0 PP
MB
5.2
0.5 PP
MB
0P
PM
B5.0
0I0% Lim
e4.8
300400
200
3.0
2.55atOO
5.0
T
SU
NF
LOW
ER
0 Lime
------.15% Lim
e1.0
12_5 %
Lime
I%
Lime
NN
0-5P
PM
Boron in
N!
05
II!,a,.25
Nutrient
Solution_
25
5..0
NN
N.25
LO
N1.0
0_.25
200300
40050P
600700
800900
1000
Ca:B
RA
TIO
(p.pm/p.p.m
)Fig0 2s.
The relation of the am
ount of calcium in sunflow
ers to theconcentration of boron in the
nutrient solution and to the calcium boron ratio
of the plant material.
0-
-0
0J0
5.5
5..0
4.5
0.5
-7-
260
220
$80
z000a. $00
60
5.05.0
10
\\
1.0
.25
10
.250.5
0 Lime
250/
Lime
0 2.5 %Lim
e$0 %
Lime
0-5P
PM
Boron in
Nutrient
Solut ion-
a.25
.2s
SU
NF
LOW
ER
20tOO
200300
400500
600700
800900
$000
Ca:B
RA
TIO
(p.p.m/p.p.m
)Fig0
35.T
he relationship of the aiount of boron in eunflower
to the concentration of boron in thenutrient solution and the calcium
boron ratioof the plant inateria1.
wI60
0Cl)
48,40$00II
/
500600
-700
Ca:B
RA
TIO
(p.p.m/p.p.m
)800
900
Ftg
LieT
he effect of borou Oonoentration in the nutrient solution upon the calcium
boronT
atto at Tariols calcium
-oarbønate concezatrtionnirs. the
médium
.
l000
SU
NF
LOW
ER
2005..O
PP
MB
$0P
PM
B5..O
90
PP
MB
0tO: %
Lime
ISO
3.5
5.0
3.0100
5.0/5.0
I,0A/0.5
N
25
1.0
SU
NF
LOW
ER
0Lim
e
0.25 % Litne
2...5% Lim
etO
% Lim
e0-5 P
PM
Boron
in
Nutrient
Solution_
N'N
25
\0.5\
0
200300
400500
.600700
800900
1000
Ca:B
RA
TIO
(p.p.m/p.p.m
)Fig.
5s.T
he effect of varying the quantities of lime and boron in the nutrient solution upon
the yield of cotton and calcium boron ratio in the plant0
5.0
4,5
CDj4.O
-JL&
J
>-
80Umcr0()<
.60
00..40C
/) I 20
L00
.200100
25-yI2.5
10p
2.5
0--0
- :-- -.-2.5 S
UN
FLO
WE
R
5.0P
PM
Boron
0.5P
PM
Boron
0P
PM
Boron
0l0 % Lim
e
0
800900
1200200
300400
500600
700
Ca:B
RA
TIO
(p.p.m/p.p.m
)Fig. 6s.
The effect of the concentration
of boron in the nutrient solution upon the weight of
borm aorbed and upon the
calcium boron ratio in sunflew
er plants when the lim
eyarie s from
3.
.25
48
Inter.retation of Gra.hjcal Sunflower Results
The reader is here referred to Figures is, 2s, 3s, 4.3,
5s, 6s (the letter "s's meaning sunflower), from which the
following deductions are made:
On the basis of Figure 15 it is shown that when boron
Is limiting in a culture medium, the maximum flue-
tuation in the calciurn:boron ratio results. The im-
portance of this point is reflected in the yield, and
is confirmed by numerous literature references (25,27)
(30,31) wherein boron-deficiency symptons developed in
field crops only after "excessive" soil liming. It is
shown here that when boron is limiting in a soil, a
small addition of lime may be very stimulating to the
plant; but that further additions in this case are
most detrimental - much more detrimental, for example,
than in the case where the plant is feeding from a
0.5 p.p.m. boron nutrient solution.
The 5.0 p.p.m. boron curve, when compared with the cor-
responding curve of Figure 4.s, shows that the calcium
in the plant exerts an ameliorating effect on boron
toxicity as determined by crop yield.
Macroscopic boron toxicity characters were evident in
all of the 5.0 p.p.ni. boron pot cultures; and when
analyses were made, this point was confirmed.
2.5
2.0200300
.25
tO
V2.5
900I
}I
II
10001300 1500
400500
600700
800C
o:BR
AT
IO(p.p.m
/p.p.m)
-Fig. ic.
The effect of
over_11Iflg
Onyield of cotton at various concentrations of boron in
-- 1ture
solution.
4.5
CO
TT
ON
4.05.0
PP
M B
0.5P
PM
B
-O P
PM
B0-10=
% Lim
e
3.5
.400
w0C')
z0.200
Ui
CD
.100
.080.060.040.020
tO
0
.2 5
300
Fig. 140.
.25400500
600700
Co:B
RA
TIO
(p.T
he effect of the conoentration of boron in theboron absorbed and upon the calcium
boron ratiotent of the m
edium is varied from
0 - 10%.
CO
TT
ON
5 PP
M B
oron.------ .5 P
PM
Boron.
0 PP
M B
oron.
O - 10
(%)
Lime.
800900
p. m/p.p.m
)nurient solution upon thein cotton plants w
hen the
11001500
weight of
limo con-
4.5
4.0
c3.O-j
2.5
CO
TT
ON
0 Lime
-.25 %
Lime
2.5 % Lim
e10 %
Lime
0-5P
PM
Boron
in
Nutrient
Solution_
2.0200300
400500
600700
800C
a:BR
AT
IO(p.p..m
/p.p.m)
Fig0
5°.T
he effect of varying the quantities ofand boron in the nutrient
o1ution upon theyield of cotton1 and the oalci
boron ratio in the plant.
0
9001000 1200
1500
U) 130
125
HO
25
I'100
IiP
lOo
Il
Ui
,'
L"I
'
O9Q
d'Cl)
25I
o8OI
C)
IcQ
(7060501200
plo
/2..5
/\).2.5
300400
500600
700800
9001000
300 1500C
o:BR
AT
IO(p.p.m
/p.pm)
Fig
6c,T
he effect of boronconcentration in the nutrient solution upon the calcium boron ratIo
at Tarious calcium carbonate concentrations in the medium.
CO
TT
ON
5.0P
PM
B0.5
PP
M B
0P
PM
B0-10=
% Lim
e
l0
0
25 -
ci. The inflections of the various curves in Figures is
and 2s illustrate the close correlation between
boron and calcium content of plants.
e. The effect of this correlation on yield is brought
out in Figures is and 5s.
Results with Cotton as Test Plant
Referring to Figures ic, 4.c, 5c, and 6c, we may
draw the following generalizations:
As in sunflower, Figure ic illustrates wide fluctua-
tions in the calcium:boron ratio and yield when
boron is limiting in the soil.
The optimum calcium content of the nutrient media is
0.25 per cent calcium in all cases, regardless of
the boron content of the media. When the boron con-
centration is at the toxic level, the ameliorating
effect of the lime is not operative beyond 0.25 per
cent lime on the soil basis.
Macroscopic boron-toxicity symptoms, except for plant
size, were not so evident as in sunflower.
The inflections of the curves in Figures ic, c, 6c
illustrate the close correlation between the calcium
and boron content of the plant.
The effect of these inflections on yield is brought
out in Figure 50. The cotton and sunflower curves
show that on an average the cotton plant
50
requires a lower calciuni:boron ratio than does sun-
flower grown under similar average conditions. Since
cotton seems to be less tolerant to lime than sun-
flower, it is thought that these curves indicate that
cotton prefers a medium lower in boron than sunflower.
This conclusion is confirmed by Drake, et al (14).
These results will probably not be applicable to
field practices. The relationship of calcium to boron in
the plant is one of considerable complexity, and no doubt
it is affected by many environmental factors besides the
lime and boron content of soils.
It is the author's opinion that a relationship,
whether a ratio or any other mathematical expression,
should exist between any two variables and the plant re-
action as determined by yield, plant-deficiency symptoms,
or otherwise. The calcium:boron ratio is not unique in
this respect. However, the crop losses due to deficiency
diseases resulting from overliming are unique in their
severity; and this condition, in relation to the calcium:
boron ratio and the plant yield, is clearly brought out
in this experiment.
0.32I030
IIIO
28
0,20
0.18
oa60
-0
8.09.0
1020
3.0!*0
5060
7.0PflC
!L
IME
yig isoeaverage
percentage of 1hosphOru8 in plants as related to the
UIØ
c..t.nt of the soi1
l0O
Cotton
Sunflower
130
9080
700
PER
OE
NT
LIM
E
Fig. 2sc. The avee peroeritage of Iron in a p1t as reIaed to the lim
eoontenb O
f the soil,
Cotton
Sunflower
ci
0-------O
1,02Q
03.0
LO
5.06.0
708.0
9.0.Io.o
4.5
I
0
10
0.5.25
510
25
1,0
-.0
---Sunflow
er-C
otton
5.0-0 PP
MB
--
0IS
O200
300400
500600
700800
900A
VE
RA
GE
Ca: B
RA
TIO
(p.p.m/ p.p.m
)Fig0 3sc.
The optim
um boron concentration of the m
edium for cotton and sunflow
er when yield
is averaged for all lime concentrations.
1000
- LçJ GILL
PPM BORON
0 G5
1-2 p
DISTRIBUTION OF BORON IN THE IRRIGATION WATSOF CERTAIN DRAINAGE AREAS OF ARIZONA
L
.5 - 1QO
2-5
MIDDLE
T
Lfl7LECOLORADO
AREA
ST. DAVID I
UPPER GILA
FIG. 2 MAP OF fiRIZ0NA SHOVING BORON DISTRIBUTION IN RATIONTO DRAINACF AEEAS WITTI THE STATE.
SULPHURSPRINGS.
VAL±EJ
51
DISTRIBUTION OF BORON IN THE IRRIGATIONWATERS OF ARIZONA
This investigation was suggested by numerous analyses
made of surface and underground waters from various loca-
tions in Arizona. A partial sunimary of the analyses will
be presented in this section of the thesis. Some of the
samples were received from citizens in various parts of
the state who desired to have them analyzed for their boron
content; others were taken by the author on field trips
throughout the state; still others were collected by
Professor H.V. Smith In connection with his fluorine inves-
tigations. Some were brought in by members of the Experi-
ment Station staff. In all cases an effort was made to
ascertain the exact point at which the water was sampled.
It was therefore possible to classify these waters
into the respective drainage districts to which they be-
long:
Sulfur Springs Valley
Salt River Valley
Upper Gila Valley
Middle Gila Valley
Lower Gila Valley
Hassayanipa River Drainage Area
52
Little Colorado Drainage Area
Miscellaneous
The data are assembled in Table 20. In this table cer-
tain analyses are marked with asterisks. One (*) signifies
that the wells are not used for irrigation purposes, and
(**) indicates that the wells are no longer being used as a
source of water for irrigation.
TA
BL
E20 -
BORON CONTENT OF SURFACE AND UNDERGRDUND WATERS
OF
AR
IZO
NA
Sam
ple
No.
Location
Ow
neror Source
Wel
lNo.
Boron
content
(..in
Sulf
urSprings Valley
1Near MeNeal
Gile's well
0.21
2If
If0.
283
'IMiller's well
O .13
4.'I
Double adobe well
School well
.30
5MoNeal
MoNeal Store well
0.17
Salt River Valley
421
Sec. 18, T.2 N.R. 4. E.
398*
*Woolsey well
6"
1.04.
292
""
0.61
201
Near Laveen
Agua Fria School well
0.24.
208
Near Phoenix
Arc
adia
well
81.05
210
70.17
212
"'
"3
0.13
213
""
60.20
217
"Tempe
Win
.Greiss, canal
0.05
218
ftwell
0.98
205
"Phoenix (Camelback Rd.
&40th st.)
S.R.V.W.U.
canal
0.19
216
'"
A.C
. Pre
scot
t wel
lL
i..17
*211
"Geo. Katisch well
0.19
399
""
Arc
adia
wel
l1
400
""
240
13
0.4.
4.02
4.
O.8
Sample
No.
Location
Well
Owner or Source
No.
Boron
content
(Dpm
J
403
Near Phownix
Arcadia well
Upper Gila Valley
50.
95**
24.0
24.1
22 243
24.6
24.9
20
Fort Thomas
Geronimo
Glenbar
Apache
Gila River
Gila River (near Duncan)
Bylas
0
0.29
0.50
0 24
0.05
Trace
City well
Texaco Service Station
wel
lM
.T, F
ergu
son
wel
l
U.S.A. reservoir
Culvert & Malone Service
251
252
253
268
Solomonvifle
Pima
Safford
Thatcher
Station well
Irrigation ditch
ifif
City water
Irrigation ditch
0.50
0 07
0.07
Trace
0.06
Middle Gila Valley
206
207
264
265
267
256
257
226
231
297
Sacaton bridge
1/2 ml. north of Randolph
Seneca
Globe
MiamI
Flor
ence
Florence Junetion
GIla Bend
10 miles west of Casa Grande
Coolidge
0.08
0 05
0.00
0.04
Trace
0 12
0.04.
0.8I.
0.15
Canal
Well if
City water
ftif
I,if
Well
City water
E.H. Smith well
U.S .Dept, Interior,
298
299
300
301
It I, It if
Indian Service well
ifif
I,-if
I,if
1fif
2 3 If 5
0.00
0.21
0.16
0.14.
0.08
302
Coo
lidge
303
304.
305
306
if30
730
830
931
031
131
231
331
4.31
531
631
731
831
932
032
132
2ft
323
324.
325
ft
326
327
328
329
ft33
0
U.S
.Dep
t.In
dian It I, ft I, 1, ft ft ft if ft ft if if ft ft lt
Inte
rior
,se
rvic
e w
ell
ft
Wel
lN
o.
Bor
onco
nten
t(.
.in)
60.
127
0.13
7A0.
178
0.14
90.
0710
0.11
110.
15lix
0.39
120.
1713 14
.0.
0515
0.33
160.
2017
0.30
180.
2519
0.21
20.
0.42
210.
5722
0.i9
230.
5824
.0.
4.8
250.
1426
0.28
270.
1828
0.23
290.
5530
.0.
6631
0.02
320.
20
Sarn
.ple
No.
Loc
atio
nO
wne
r or
Sou
rce
$a.p
1eN
o.L
ocat
ion
Ow
ner
or S
ourc
ee1
lN
o.
Bor
onco
nten
t
331
Ooo
1i.g
eU
.S. D
ept.
Inte
rior
,In
dian
Ser
vice
wel
l33
0.36
332
333
I, ft34 35
0.08
0.16
334
'III
1136
0.06
33.5
370.
3433
6ft
if38
0.24
337
338
ft ftft
IT39 4.
00.
110.
44.
339
34.0
1 ifI'
41 4-45
0.66
0.31
34.]
.34
2if ft
1T3-
4.6
2-l7
0.54
.0.
2434
.3ft
1?49
0.42
344
34.5
34.6
3i1.
734
8
if ft ft ft if
ft50 5. 52 53 54
0.25
0.37
0.74
0.19
0.29
349
It55
0.45
350
1156
0.37
35'
'I
352
'I58
0.22
353
ftft
590.
0835
1i.
ITT
IU
355
356
ft ifft
60 610.
240.
0635
7ft
""
620.
1235
8ft
It63
0.25
359
ft"
640.
3036
036
1I, ft
I'65 66
0.51
0.30
Sam
ple
No.
Loc
atio
nO
wne
r or
Sou
rce
Bor
onW
ell
cont
ent.
No.
(ppm
)
362
Coo
lidge
U.S
. Dep
t. In
teri
or,
Indi
an S
ervi
ce w
ell
670.
14.
363
680.
0736
14.
if69
0.37
365
'"
700.
1236
671
0.13
367
1!72
0.10
368
ht73
0.17
369
74.
0.50
370
"75
0.73
371
1?76
0.22
372
770.
005
373
iftt
078
0.29
374
I!U
"80
0.04
.37
5"
810.
0737
6i'
820.
0537
7l
it83
0.03
378
"84
.0.
0637
985
0.44
.38
0it
it86
0.05
38].
872.
4038
288
2.20
383
ifU
93.
0.42
384.
ii92
0.83
385
Uit
930.
7638
694
.0.
5838
797
0.11
388
980.
0838
9'
99 b
roke
n39
010
00.
7139
].0
ii10
10.
4639
20
102
1.07
Saniple
NO.
Location
Owner or Source
Well
No,
Boron
content
(ppm.)
393
Coolidge
U.S. Dept. Interior,
Indian Service well
103
0.20
394.
104
0.29
395
1"
105
2.92
396
1*106
1.61
397
Evergreen or Bradley well
0.16
Lower Gila Valley
270
Boll, Arizona
Mohawk Municipal Conserva-
tion Dist. well
11.4.5
271
"'I
"3
0.4.2
272
4.
2.11
273
"1?
72.
1627
4."
ft9
1.36
275
."l(
1.14
276
'!"
11
0.52
277
""
12
2.30
278
"14
0.50
279
"15
0.52
280
"ft
$116
0.64
281
180.42
282
'I19
1.82
283
"'
202.
0028
4"
222.
7328
5"
23
0.87
286
24
0.50
ftft
"26
0.74.
288
"27
0.42
289
1I'
28
0.40
290
"29
0.53
291
310.
36
233
234.
235
236
237
238
Little Colorado Drainage Area
Irrigation reservoir
Irrigation water (spring)
City water
Drilled well
Little Colorado River
White River
Well
Irrigation ditch
flV
t
Little Colorado River
City water (artesian)
Clear Creek
Irrigation ditch
Trace
0.0
0.0
0.0
0.05
0.00
0.18
0.07
Trace
0.23
0.00
0.11
Trace
Well
Location
Owner or Source
No.
Boron
content
(ppm)
Oils. Valley, 10 ml. E. or Yuma
Tohn Bretz well
0.25
Weilton
Hallenbeck
I'1.66
Welch
0.32
Aztec
railroad
1.60
Araby
0.24.
Ralph's mill
1.72
Yuma
Ne' University Farm well
0 20
Taena
2.32
Hassayampa River Drainage
Tonopah, Arizona
Oscar's Mineral Hot Springs
0.85
ifBud Beauchamp
0.66
'INornian Nellis
1.05
' T 2N B 7W Sec. 25
3.H. Beauchamp
0 88
ifGrace Herrihg
0.55
Lomeraux
0.95
24.4.
st. rohns
24.5
C onoho
24.7
MeNary
24.8
White River
24.9
Eagar
250
Fort Apache
258
Toseph City
259
Taylor
260
Snowflake
261
Holbrook
262
263
Winslow
266
Showlow
Sample
1o.
221
223
224.
225
227
228
229
230
Bor
onSa
mpl
eW
ell
cont
ent
No.
Loc
atio
nO
wne
r or
Sou
rce
No.
(ppm
)
Mis
cella
neou
s7
St..
Dav
id.
Scho
ol w
ell
0.06
215
Pica
cho
Mon
tezu
ma
Inn
wel
l0.
0122
0D
eer
Val
ley
1.F.
Ale
xand
er w
ell
0.08
61
The data of the foregoing table bring out certain
significant points of interest in connection with the boron
problem. For purposes of the present discussion, the areas
referred to are located on a map shown in Figure 2.
Sulfur Springs Valley:
Water samples collected from Sulfur Springs Valley
showed not more than 0.3 p.p.m. of boron. It is generally
assumed that this amount will not be toxic to boron-
sensitive crops if drainage conditions are good, and if
ordinary irrigation practices are followed.
Salt River Valley:
The number of water samples from the Salt River Valley
in this investigation is rather limited. A sample from the
Arizona Canal, taken at Camelback and J0th street, showed
the relatively small amount of 0.19 p.p.in. of boron. The
water from the canal serving the William Greiss citrus
grove 5 1/2 miles southwest of Tempe showed only 0.05 p.p.
m. On the other band, his domestic well contained o.9g
p.p.m. A neighbor, A.C. Prescott, has a domestic well con-
taining 4.17 p.p.m. of boron. Inasmuch as these waters
are not being used for irrigation, the boron problem in
relation to its probable damage to citrus, is not important
in this investigation.
62
Several irrigation districts or private enterprises,
outside of the Salt River Valley Water Users' Association
District, are using pump water for irrigation. Outstand-
ing among these is the Arcadia district. For some years
waters containing an average of 0.8 p.p.m. were used to
irrigate the citrus groves on this tract. Boron toxicity
syiptoms, as evidenced by characteristic yellowing of
the leaf and browning of leaf margins and tips, were not-
iceable throughout the groves. Later these wells were
abandoned in favor of wells nos. 3, 6, 7, whose average
boron content was found to be less than 0.3 p.p.in. At
present there appears to be no evidence of boron injury
on any tree in the tract.
In 1929 Scofield and Wilcox (4.1) reported 0.13 p.p.ni.
and 0.44. p.p.m. boron in the waters from the Verde River
and the Roosevelt Irrigation District near Litchfield Park.
Upper Gila Valley:
The irrigation waters of the Upper Gila Valley from
the river Itself, from canals fed by the river, and from
wells show the presence of boron in amounts from traces
up to 0.5 p.p.m. Inasmuch as citrus is not grown in this
district, boron toxicity is not a problem. Gila River
water is exceptionally low in boron.
Middle Gila Valley:
Very limited amounts of boron are found in the Gila
63
River water in this district. The Gila Bend city water
contains O.4. p.p.m. of boron which, if used for citrus,
might eventually become toxic.
Through the courtesy of C.F. Moody, Project Engineer,
U.5.D.I. Indian Service, Coolidge, about 100 samples of
irrigation water from various wells on the project were
furnished for analysis. Of this number only 5 exceeded
a concentration of 1.0 p.p.m. The wells furnishing the
highest concentration of boron are located west of Casa
Grande. Inasmuch as the water is probably blended, and
because alfalfa and cotton are the principal crops grown,
the damage, if any, will be small so long as these condi-
tions prevail.
Lower Gila Valley:
Through the courtesy of the Mohawk Municipal Conser-
vation District #22, samples of water from the District
wells were obtained for analysis. Nine of these samples
contained in excess of 1.0 p.p.in. of boron. The waters
as a rule are excessively high in soluble salts. The
Reclamation Service has plans for furnishing this dis-
trict with Colorado River water. At present, due to the
unfavorable water situation, the chief crops are alfalfa
and Bermuda grass. These crops ordinarily are allowed to
produce seed.. In fact, this district produces a consid-
erable amount of a fine quality alfalfa seed. A recent
64.
article by rizzard and. Matthews (17) presents evidence
which Indicates that boron is not only desirable, but even
essential for seed production. This may explain in part
the success of alfalfa seed production in this valley.
llassayampa River Drainage Area:
Several samples of water were submitted from the
vicinity of Tonopah. Most of these samples contain be-
tween 0.5 and 1.0 p.p.m. of boron. Little irrigation
agriculture is conducted in this area.
Little Colorado River Drainage Area:
This area comprised most of the agricultural dis-
tricts in the northeastern part of Arizona. Boron con-
centrations were extremely low in all samples examined.
Inasmuch as these samples are representative of most of
the waters in this locality, it is probably safe to
assume there is no boron toxicity problem in this part of
the state.
Colorado River:
No samples of Colorado River water have been
analyzed. Scofield and. Wilcox (41), however, report
analyses of this water extending over a 10-month period.
The average for this period was 0.19 p.p.m. of boron. The
highest value reported during this period was 0.3 p.p.in.,
and the lowest a trace.
65
The average boron content of water from the Colorado
River for 1933-34. at Grand Canyon, as reported by Foster
(l6, was 0.52 p.p.m. and at Topock 0.59 p.p.ni.
Summing up the observations of the foregoing survey,
if boron toxicity becomes an important problem in this
state it is likely to occur as a result of using pump
waters from wells containing high concentrations of boron,
rather than as a result of irrigation with surface waters.
To locate all of these wells will require further investi-
gation. In irrigation projects using well waters only,
some of which are high in their boron content, it is quite
possible that the waters containing high concentrations of
boron can be blended with those of a lesser concentration.
This practice has been followed successfully in California,
where waters from some drainage areas are very high in
boron concentration. it is necessary that the respective
volumes of each of the waters be calculated in such a way
as to reduce the resulting boron concentration below the
toxic level for the particular crop. hen such a water is
used, crops should be watche4 closely for toxicity
symptoms, and soil samples should be analyzed occasionally
to insure that the boron concentration is not building up
in the soil.
66
RELATION OF BORON TO FLUORINE IN WATERS
On December 21, 1934, So éA(i.1a) suggested the
likelihood of boron and fluorides occurring together in
waters. Since that time, whenever practicable, fluoride
determinations have been made on waters which were to be
analyzed for boron. From evidence at hand, there appears
to be a definite correlation between the occurrence of
these two elements in waters. However, the results of a
statistical analysis, made on concentrations in which the
elements occur together in twenty-seven waters, are
assembled in Table and show that for these waters the
correlation coefficient is not significant. (44}
67
For the number of samples used, a significant cor-relation between these concentrations would be given by a
correlation coefficient equal to or greater than 0.381.The calculated value was 0.253.
TABLE 21 - BORON A1D FLUORINE CONCENTRATIONSOF WATERS
SampleNo.
Fluorineppm
Boronppm
200 2.6 2.4.5201 0.5. O . 24.202203
0.60.6
0.4.9O . 24.
204 6.8 2.4.3205 0.5 0.19206 0.9 0.8207 3.0 0.05208 1.3 1.05209 4.0 3.06210 0.7 O .17211 0.7 0.19212 0.7 0.4.3213 0.7 O 20214 0.50 1.16215 0.50 O 01216 12.00 Ii.. 17217 0.5 0.05218 3.0 0.98292 0.30 0.61293 1.50 0.4.4.409 1.7 0.65410 0.9 0.654.11 0.0 0.204.12 1.8 O 124.13 4.0 0.584.14. 11.0 1.89
68
BORON CONTENT OF PlANTS
Several investigators have found it more desirable
to use foliar analysis for the detection of boron toxicity
or deficiency than soil or water analysis. Scofield and
Wilcox (1+1) (15), for example, state that 0.5 to 1.0
p.p.m. of boron in irrigation water may be toxic to wal-
nuts and lemons, but not to more tolerant crops such as
corn, milo, barley, wheat, cotton, or alfalfa. The boron
content of the leaf builds up with age. This is the
reason old citrus leaves which have grown in the presence
of boron are particularly high in this element. The
following table, taken from the work of Scot ield and
Wilcox (4.1) shows the difference in boron concentration
between uninjured and injured lemon leaves.
SPECTROGRAJJ OF CITRUSLEAVES AND FRUIT
B
Figure 3
69
TABLE 22 - BORON CONTENT OF LEMON LEAVES CLASSIFIEDWITH RX'ERENC TO TIlE INJIJRIOUS XFFECT
It is doubtful that boron injury will occur unless
the boron content of the lemon leaf greatly exceeds 300
p.p.m. Other citrus leaves, such as those of oranges and
grapefruit, are injured by slightly higher concentrations
of boron; but, according to Scofield, they seem to be some-
what more resistant than lemon.
During the course of this investigation it was con-
sidered desirable to make analyses of plant material from
various sources for boron. Some of these analyses can be
correlated with the boron content o the water used for
irrigation. These analyses appear in Table 23.
Condition of leavesBoron conJmJ
Lowest Hihest Mean
Uninjured. 38 285 157
Doubtful 302 380 34.0
Injured 4.60 992 64.6
TA
BL
E23
-BORON C0TENT OF PLANT MATERIAL
No.
Boron content
irriga
tion water
Plant Material and Description
Source
(ppm)
Plant
Material
(ppm)
1Grapefruit leaves
Grunow
0.75
365
2 3
III,
O'Connell
U",
(yellow leaf)
MoKale
ft",
(normal leaf)
0.7
0.7
50
10012
5 6
I,(yellow leaf)
'I!
(yel
low
leaf
)I\
1 1ott
135
(Arcadia)
0.7
375
7Grapefruit peel
Grunow
0.75
58 9
101112
1314
Alfalfa
Yavapal Co.
ftIf
ft$1
ftif
ftI,
Grapefruit rind, stylar end (pinknose)
Grunow
ftft
"st
emIt
0.75
0.75
18
201714
34.
If4
4.0
15U
flle
aves
I,0.
7537
016
Alfalfa
Silva
5517 18
Eucalyptus (injury)
Woolsey
Tasmine
(ft
1?3.98
3.98
615
14.40
19
20
Grapefruit rind, stylar end. (normal)
Streets
ft'
stem
ffif
2438
21
Alfalfa
Briggs
(Yu.
ma)
0.19
120
22
Citrus leaves (yellow)
Wharton
45
23
24.
I,Grapefruit leaves (normal)
,composite 3 trees,
(pin
knos
e)Grunow
0.75
150
1160
No.
Plant Material and Description
Boron content
Irriga-
tion water
Source
(ppm)
Plant
Material
(ppm)
25
Grapefruit leaves (3-7 pinknose)
Grunow
0.75
1260
26
27
9'
,control
(normal)
I,
Burgher
0.75
0.19
852
100
28
rind, stern end, (pinknose)
Grunow
0.75
26
29
30
",stylar"
"stem
'(3-7)
I, It0.75
0.75
38 8
31
stylar
UIt
0.75
56
32
"stem
"U
0.75
34.
33i
stylar "
'10.75
76
34.
"stem
Burgher
10
3 5
" stylar
"U
10
36
juice, stein end, (pinknose)
Grunow
0.75
93738
39
UIt
"stylar
Itft
Ustem
"(control)
UI?
stylar
ftft
0.75
0.75
0.75
9.2
7.6
7.6
40
I,11
(pinknose 3-7)
U0.75
9.2
4.1
ftft
U1?
0.75
6.0
4.2
43
Unormal)
aft
aBurgher
It0.8
1.0
44
Corn meal
T.M. Giles,
McNeal
0.21
0.0
4.5
4.6
Corn leaves
a1,
U
0A
,MoNeal
0.21
0.28
10 0
8.0
47
"meal
Onion Miller
0.13
0.0
Double Adobe Dist.
48
U11
R.E
.A.,
MoNeal
0.28
0.0
4.9
Tomato loaves
Itft
0.28
4.3
5051
Lettuce
Hegari leaves
Salt River Valley
ftIt
10 20
No.
Plan
tMaterial and. Description
Boron Content
Irriga-
tion water
Source
(ppm)
PlIant
Material
(pprn)
52 53 54.
55
Hegari grain
?1It
$1ft
Alfalfa
Salt River Valley
1tft
aU
1tft
0 0 0 3556
Sexton, (Arcadia)
0.70
188
57Grapefruit
Itft
0.70
750
58
Apricot leaves
11ft
0.7
4.7
59Cotton leaves
ft0.7
85
60
Orange leaves
A.0. Prescott
170
61
62
Grapefruit leaves
.Lem.on:
Gec. Katisch
ftft
0.19
0.19
212
188
63
64.
Naval orange
"
Alfalfa
A.0. Prescott
ft287
4.7
65
Grapefruit leaves
Win. Greiss
0.05
263
66
Beet leaves
L.L. Holmes,Phoenix
26
73
There is some evidence that the water containing 0.7,5
p.p.rn. of boron is causing some injury to the citrus trees.
The injury is not great, but sufficient to cause a some-
what unhealthy appearance of the trees. Undoubtedly yields
are reduced. Another condition noted in the grove is an
abnormality of the ripe fruit. The stylar end does not
reach full size and is rather pin1ish in appearance. The
juice is very bitter. This condition is commonly re-
ferred to as "pinknose." The condition has not been
definitely related to boron, but the presence of boron in
the irrigation water and in the leaves of the trees is evi-
dence of an unhealthy condition which might manifest itself
in this way. If samples 21+ to 27 inclusive, of Table
are compared, it will be seen that the leaves from the
Burgher Grove, irrigated with Arizona canal water, contain
only 100 p.p.m. of boron. The three samples of leaves
from the Grunow Grove contain B52 to 1260 p.p.m. of boron.
These results were confirmed by spectographic analyses
(see Figure 3 ) niade on the plant ash by Professor A.J.
Thompson of the Mining and Metallurgy College. Most of
the Grunow trees produce "pinknos&t grapefruit. This grove
is being given special study and treatment by the
Horticulture Department of the Arizona Agricultural
Experiment Station.
74
Inasmuch as the boron content of most of the waters
and. plants reported. here is low, it is doubtful if any
laTge areas in the state re 111 serious danger of boron
toxicity.
)
75
TABLE 24. - RESULTS OF SPECTOGRAPHIC ANALYSES OFPLANT MATERIALS FROM GRAPEFRUIT
AFFLICTED WITH PINKNOSE
Name Usedfor Identi- Samplefication No. Plant Material
Conditionof
Fruit
Densito-meter
Reading(Densit
Grunow 24. Leaves Pinknose 10
Grunow
Grunow
25
26
1,
II
?1
n
10
10
Burgher 27 U Normal ap-pearance 6
Grunow 28 Grapefruit rind(stem end.) Pinknose 6
Grunow 29 Grapefruit rind(stylar end) n 7
Grunow 30 Rind (stem end) TI7
Grim ow 31 11 (stylar end) 8
Grunow 32 (stem end) Ii 8
76
SUMMARY
A study was made of boron toxicity and. deficiency
by way of sand, culture technique with cotton and sun-
flower.
A partial survey of surface and underground waters
of Arizona has been made.
Nitrates and possibly nitrites interfere with the
Naftel turmeric analytical procedure for the determination
of micro-quantities of boron in soils and plant materials.
This condition was not obviated by ignition at 12000 F,
or by reducing agents.
4.. The extent of boron fixation by soils depends to
a large degree upon the concentration of boron in the
liquid phase, and the particle size of the solid phase.
The extent of fixation Increases with both particle size
and concentration.
The fixation of boron in the soil is a temporary
condition, pending the application of boron-free water.
Reagent grade chemicals are not reliable for
plant cultures used in determining boron deficiency.
Lowering the pH releases temporarily fixed borons.
No general relation between boron fixation and
the presence of lime was observed that could not be inter-
preted in terms of pH effects.
77
The oalcium:boron ratio within the plant reflects
field conditions, which are inportant factors determining
yield, and is recommended as a criterion for further use
in the interpretation of boron deficiency data.
The calcium in the sunflower plant has an anielior-
ating effect on boron toxicity as indicated by yield.
Under the conditions of the experiment, the amount
of calcium in the soil is reflected in the iron concentra-
tion of the plant.
The percentage of phosphorus in the oven-dried
plants is decreased by the addition of lime to the soil.
Rock phosphate is capable of absorbing as much
boron from solution as a corresponding weight of soil
of high boron-absorpiflg capacity.
Activated bone absorbs considerably more boron
from solution than a corresponding weight of rock phosphate
or soil of high-absorbing capacity.
13. Treatment of soil with certain amendments and
fertilizer materials may be considered somewhat analogous
to the phosphate "aotivatiofl process.
78
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