A fertility program for celery production on Everglades organic soils

Material Information

A fertility program for celery production on Everglades organic soils
Series Title:
Bulletin University of Florida. Agricultural Experiment Station
Beckenbach, J. R ( Joseph Riley ), 1908-
Place of Publication:
Gainesville Fla
University of Florida Agricultural Experiment Station
Publication Date:
Physical Description:
39 p. : ill., charts ; 23 cm.


Subjects / Keywords:
Celery -- Soils -- Florida -- Everglades ( lcsh )
Celery -- Fertilizers -- Florida -- Everglades ( lcsh )
bibliography ( marcgt )
non-fiction ( marcgt )


Bibliography: p. 36.
General Note:
Cover title.
Bulletin (University of Florida. Agricultural Experiment Station)
Statement of Responsibility:
by J.R. Beckenbach.

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
027189370 ( ALEPH )
18214555 ( OCLC )
AEN5190 ( NOTIS )


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Full Text

Bulletin 333







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Fig. 1.-A commercial field of celery on sawgrass peat land.

Bulletins will be sent free to Florida residents upon request to

March, 1989





John J. Tigert, M.A., LL.D., President of
the University
Wilmon Newell, D.Sc., Director
Harold Mowry, M.S.A., Asst. Dir., Research
V. V. Bowman, M.S.A., Asst. to the Director
J. Francis Cooper, M.S.A., Editor
Jefferson Thomas, Assistant Editor
Clyde Beale, A.B.J., Assistant Editor
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Manager
K. H. Graham, Business Manager
Rachel McQuarrie, Accountant

W. E. Stokes, M.S., Agronomist'
W. A. Leukel, Ph.D., Agronomist
G. E. Ritchey, M.S., Associates
Fred H. Hull, Ph.D., Associate
W. A. Carver, Ph.D., Associate
John P. Camp, M.S., Assistant
Roy E. Blaser, M.S., Assistant
A. L. Shealy, D.V.M., Animal Husbandman'
R. B. Becker, Ph.D., Dairy Husbandman
L. M. Thurston, Ph.D., Dairy Technologist
W. M. Neal. Ph.D., Asso. in An. Nutrition
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarian
N. R. Mehrhof, M.Agr., Poultry Husbandman
. W. Anderson, M.S,. Asst. Poultry Hush.
W. G. Kirk, Ph.D., Asst. An. Husbandman
R. M. Crown, B.S.A., Asst. An. Husbandman
P. T.T Dix Arnold, M.S.A., Assistant.Dairy
L. Rusoff, M.S., Asst. in An. Nutritions
R. V. Allison, Ph.D., Chemist'
F. B. Smith, Ph.D., Soils Chemist
C. E. Bell, Ph.D., Associate
R. B. French, Ph.D., Associate
H. W. Winsor, B.S.A., Assistant
J. Russell Henderson, M.S.A., Assistant
L. W. Gaddum. Ph.D., Biochemist
L. H. Rogers, M.A., Spectroscopic Analysts
Richard A. Carrigan, B.S., Asst. Chemist
C. V. Noble, Ph.D., Agricultural Economist'
.iruce McKinley, A.B., B.S.A., Associate
Zach Savage, M.S.A., Associate
A. H. Spurlock, M.S.A., Assistant
Ouida Davis Abbott, Ph.D., Specialist'
Ruth Overstreet, R.N., Assistant
J. R. Watson, A.M., Entomologist'
A. N. Tissot, Ph.D., Associate
H. E. Bratley, M.S.A., Assistant
G. H. Blackmon, M.S.A., Horticulturisti
A. L. Stahl, Ph.D.. Associate
F. S. Jamison, Ph.D., Truck Horticulturist
R. J. Wilmot, M.S.A., Specialist, Fumigation
R. D. Dickey, B.S.A., Assistant Horticulturist
J. Carlton Cain, B.S.A., Asst. Horticulturist
Victor F. Nettles, M.S.A., Asst. Hort.
W. B. Tisdale, Ph.D., Plant Pathologist'
George F. Weber, Ph.D., Plant Pathologist
R. K. Voorhees, M.S., Assistants
Erdman West, M.S., Mycologist
Lillian E. Arnold, M.S., Assistant Botanist


R. P. Terry, Chairman, Miami
Thomas W. Bryant, Lakeland
W. M. Palmer, Ocala
H. P. Adair, Jacksonville
Chas. P. Helfenstein, Live Oak
J. T. Diamond, Secretary, Tallahassee


L. O. Gratz, Ph.D., Plant Pathologist in
R. R. Kincaid, Ph.D., Asso. Plant Pathologist
J. D. Warner, M.S., Agronomist
Jesse Reeves, Farm Superintendent
A. F. Camp, Ph.D., Horticulturist in Charge
John H. Jefferies, Superintendent
Michael Peech, Ph.D., Soils Chemist
B. R. Fudge, Ph.D., Associate Chemist
W. L. Thompson, B.S., Asst. Entomologist
W. W. Lawless, B.S., Asst. Horticulturist
J. R. Neller, Ph.D., Biochemist in Charge
J. W. Wilson, Sc.D., Entomologist
F. D. Stevens, B.S., Sugarcane Agronomist
Thomas Bregger, Ph.D., Sugarcane
Jos. R. Beckenbach, Ph.D., Asso. Horticul.
Frederick Boyd, Ph.D., Asst. Agronomist
G. R. Townsend, Ph.D., Associate Plant Path.
R. W. Kid'er, B.S., Asst. Animal Husbandman
W. T. Foresee, Ph.D., Asst. Chemist
B. S. Clayton, B.S.C.E., Drainage Engineer2
W. M. Fifield, M.S., Asst. Horticulturist
S. J. Lynch, B.S.A., Asst. Horticulturist
Geo. D. Ruehle, Ph.D., Asso. Plant Ptathologist
W. F. Ward, M.S., Asst. An. Husbandman
in Charge2

M. N. Walker, Ph.D., Plant Pathologist In
K. W. Loucks, M.S., Asst. Plant Pathologist
Plant City

A. N. Brooks, Ph.D., Plant Pathologist
R. N. Lobdell, M.S., Asst. Entomologist
A. S. Rhoads, Ph.D., Plant Pathologist
A. H. Eddins, Ph.D., Plant Pathologist
Samuel O. Hill, B.S., Asst. Entomologist2
David G. Kelbert, Asst. Plant Pathologist
R. W. Ruprecht, Ph.D., Chemist in Charge,
Celery Investigations
W. B. Shippy, Ph.D., Asso. Plant Pathologist
E. S. Ellison, Meteorologists
B. H. Moore, A.B., Asst. Meteorologist2

'Head of Department.
2In cooperation with U.S.D.A.
2On leave.



Cultural procedure followed ............................ ............ 6
Stalk size distribution in relation to yield .....................-- ....- 7
Description of the Experimental Plots ................. ........... 9
Influence of various "trace" elements upon celery yields ................ 11
Depth of the water table ............ ............. ................. ..... 13
Cost of growing celery in the Everglades .................. ........... 13
/Influence of nitrogen upon yields and costs ............... ............. 16
Influence of potassium upon yields and costs ............................. 22
influence of phosphates upon yields and costs .................----.......-- -. 27
ethod and rate of application of fertilizer ....................................... 30
Miscellaneous suggestions ............ .........-------.........---... .. .. .. 32
Summary and abstract ........... ........................... ....... 33
Acknowledgments .................. ........ ... .. .......- 35
Literature cited .......................... ........ ................. ...... 36
A ppendix ................................ ............................. ........... ........... 37


Peat and muck soils throughout the country are particularly.
well adapted to various truck crops, and especially to the leaf
crops. The rapidly increasing utilization of Everglades organic
soils for the production of celery is, therefore, a logical de-
On the other hand celery is a notoriously gross feeder, requir-
ing a heavy initial outlay of cash for fertilizer in comparison
with most other truck crops. It also requires a relatively long
growing season, commonly from 85 to 110 days after being set
in the field, depending upon the variety and time of year grown.
As long as beans were a sure money crop in the Everglades a
majority of growers concentrated on this crop, but since the
margin of profit has been steadily diminishing many growers
in the region are, of necessity, branching out into a program
of growing different truck crops. For this and other reasons,
celery production is rapidly increasing. Palm Beach County
shipped 347 carloads of celery in the spring of 1938 (3)1. In
1934 only 54 carloads were shipped (3), and in 1929 only 5 (7).
The marketing season for the region extends from early Jan-
uary through May. In comparison with other areas in the state
347 carload lots would make the area seem of minor importance,
but the extremely rapid expansion in the last few years belies
such a conclusion.

1Italic figures in parentheses refer to "Literature Cited" in the bacl-
of this bulletin.

Florida Agricultural Experiment Station

Both soil type and climate are entirely suitable for celery
production. There are several soil types, but all are of organic
nature and origin. By far the largest area is composed of the
highly organic sawgrass peat lands, which are largely still in
native sawgrass. The more highly mineralized muck soils, in-
cluding the custard apple, elder and lake bottom mucks, are
located principally around Lake Okeechobee. To a considerable
extent these latter soil types are already being intensively
cropped. Their proximity to the lake makes them almost frost
free, and they are utilized largely for the more tender crops,
such as beans, tomatoes, potatoes and sugarcane. This will
probably continue to be the case.
According to soil maps there are some two and a half to
three million acres of land classed as organic Everglades soils.
The organic layer is too shallow over some of this area for
practical cropping over a period of years. However, there are
still large areas in native sawgrass which, with adequate drain-
age, are entirely suitable for the growing of hardy truck crops.
It is into these areas that further expansion must proceed, and
for this reason most of the experimental work on celery pro-
duction has been carried out on sawgrass peat soils.
A brief discussion of some of the characteristics of these
organic soils will emphasize their suitability for growing celery.
In the first place, with adequate drainage (which should include
unit ditch control and mole drainage) the level of the water
table can be regulated and held at an optimum depth during the
winter months. The entire growing period of the winter crop
of celery comes in the dry season of winter. A dry season has
no limiting effect upon the water supply-on the contrary, it
has been found that the more prolonged the spring drouth, the
higher the yield of celery produced.
A second important factor affecting the suitability of such
a soil to celery is the fact that since it is largely organic,
the soil acts as a huge sponge, with a large capacity for hold-
ing water, adequate pore space for necessary soil air, and a fine
capacity for holding fertilizer materials, thus preventing their
rapid loss by leaching waters. This latter property insures
efficient utilization of fertilizer materials, and, therefore, reduces
greatly the tonnage per acre that must be applied, in contrast
to the amount required on coarse mineral soils.

A Fertility Program for Celery Production

A third important property of these soils is their high ni-
trogen content. Inorganic soils under continuous cropping
inevitably become nitrogen deficient, unless applications of
nitrogenous materials are made from time to time. In peat
and muck soils, natural chemical processes and micro-organisms
within the soil are always at work disintegrating the organic
material, and these processes result in a gradual release of the
nitrogen in forms available to plants.
Fourthly, almost all of these organic soils overlie marl or
limestone, and the upward movement of soil waters during the
dry season carries with it dissolved calcium and magnesium
salts. For this reason none of these soils is highly acid and the
addition of limestone or hydrated lime is neither desirable nor
There are, of course, certain disadvantages inherent in these
soils. We have already mentioned the absolute necessity of
drainage ditches, and the advantages of mole drainage. There
is also one direct danger inherent in organic soils wherever
they may be located. This is the danger of fire-a dry muck or
peat soil may be badly damaged by burning. On such a burned
soil the problem of fertilization is greatly complicated because
of the alkaline residues resulting from the burning, and since
the fertilizer problem is already a complex one the burning off
of these soils should be avoided when possible.
Peat and muck soils are almost universally deficient in both
potassium and phosphorus, and the Everglades soils are no ex-
ception. In southern Florida there may also be a deficiency of
available manganese, zinc and copper in the soil. Since the
primary purpose of a good fertility program is to make avail-
able to the growing plants a proper balance of all needed nutrient
materials throughout the growing period of the crop, several
experiments were designed for the purpose of studying this
problem. They necessarily cover such essential points as the
amount per acre of each fertilizer material which must be sup-
plied to give the best possible yield, the most satisfactory method
of applying the fertilizer, the best time for applying the fertilizer
(whether entirely before planting or in part as a side-dressing),
and, finally, the fertilizer program which will return the highest
dividends over and above the cost of fertilization per unit area.
In short, it was desired to find the most economically sound
fertility program for growing celery in the Everglades.

6 Florida Agricultural Experiment Station

Before entering into a detailed description of the experimental
work involved in the determination of the fertility program to
be suggested for the commercial growing of celery in the Ever-
glades, it is desirable that certain methods involved in the grow-
ing of the crops be explained. The cultural procedure followed
is one of these essential parts of the experimental program.
As far as possible standard commercial cultural methods were
used in all of this work. The seedlings were started in raised
seedbeds in the open field and protected by cloth shades until
the seedlings were well established, primarily for the purpose of
keeping the upper surface of the beds from drying out. These
seedbeds were pretreated with formaldehyde or other materials
for the control of damping-off fungi. The troughs between the
beds were used for irrigation purposes to keep water available
to the germinating seedlings. When the seedlings were well
established this surface irrigation was stopped and the shades
were removed. Weeding was done whenever necessary. The
seedlings in the beds also received one or more bordeaux sprays.
The seedlings were planted to the fields either by hand, using
Negro labor, or by means of a commercial plant setting machine
(Fig. 2). The latter method is to be preferred over hand setting.
Plants were set in single rows 30 inches apart, with a 4-inch
spacing between plants. This arrangement is already standard-
ized commercially, and gives approximately 52,275 plants per
acre. At time of setting the water table was brought to the
field surface by means of portable pumps installed in the adjoin-
ing ditches. Water from these ditches backed up through the
mole drains and moved to the soil surface in a short time, thus
making conditions for setting satisfactory. The water table
was allowed to drop to its normal level as soon as the plants
became reestablished in the field.
A regular spray program was followed, in that plants in the
field were sprayed weekly until papered for blanching.
The various fertilizer mixtures were made up in small lots,
in a quantity sufficient for the plots, and mixed by hand in a
small mixer. Due to the fact that the plots were relatively
small the fertilizers were also spread by hand. For the most
part the fertilizers utilized in these experiments were hand-
distributed in the opened rows at a depth of three to four
inches several days prior to the setting of the plants. In treat-

A Fertility Program for Celery Production

ments designed to compare broadcast applications of fertilizers
with the above procedure the fertilizer was applied broadcast
by hand over the entire plot area and subsequently disked in.

Fig. 2.-A commercial type of plant-setting machine in use on one of the experimental areas.

Blanching paper was applied seven to 10 days before harvest-
ing. Harvesting was done by trained crews who cut, stripped,
and graded the produce in the field. The total weight of each
grade harvested was taken for each plot, and these results were
calculated to terms of the yield in 70-pound field crates per
acre. All grades, from 3's to xx's, were considered as market-
able celery, and are included in the totals dealt with in the
subsequent discussion. Strippings were removed from the field,
except in Area 3, where they were disked in the plots on which
the plants had grown. This latter method was used with the
1936-37 and 1937-38 crops, and will be mentioned in a later part
of this bulletin.

While this relationship was studied in the fertility experi-
ments, it is not essential that it be discussed in direct connection
with the various fertilizer combinations because of the nature

Florida Agricultural Experiment Station

of the relationship.. For the purpose of simplification of the
subsequent part of this report, this section has been placed
preceding the description of the experimental plot arrangements.
Celery is commonly shipped from the Everglades region in a
crate which measures 10" x 24" x 16" and which contains
approximately 70 pounds when packed for shipment. The celery
is roughly stripped and graded in the field, the marketable celery
being divided commonly into 3's, 4's, 6's, 8's, 10's and xx's.
The 3's are the largest stalks and contain three dozen stalks to
the crate. The other sizes also indicate the number of dozen
stalks packed in the crate, with the xx's being very small. The
popular medium sized stalks are the 6's, and a satisfactory crop
is one in which the 6's make up the largest relative proportion
of the crop, with 4's, 3's, 8's, 10's and xx's following in order.
It is important that the effect of the fertility program on
the stalk size distribution be known, therefore, and fortunately,
for the average year this relationship is a simple one. It is
simply this-with a spacing of four inches between plants and
30 inches between rows as was used throughout in the experi-
mental plots, the fertility program which gave the highest yields
in the average year also gave the most desirable size distribu-
tion. For example, the highest 5-year average yield from Area
2 of these experiments was 589 crates per acre, and the average
distribution (by weight) with regard to the various stalk sizes
was as follows: 12.9% of 3's; 20.5% of 4's; 29.7% of 6's;
20.8% of 8's; 9.0% of 10's and 7.1% of xx's. In other words,
83.9% by weight of the marketable celery crop was composed
of 6's, 8's, 4's and 3's.
Of course, in years when the highest yielding fertility pro-
gram gave particularly good yields, a larger portion of the crop
was represented by 3's and 4's. Conversely, when celery yields
were relatively low, the preponderance of the crop was 6's and
8's, with a sizable proportion of 10's. However, since it is
impossible to foretell the yield at the time the fertilizer is
applied, the best that can be done is to rely upon the average,
and the average shows that when you fertilize to obtain the
highest possible yield, the stalk size distribution will take care
of itself in a satisfactory manner. For this reason, the stalk
size distribution will be disregarded in the balance of this bulle-
tin, and the fertilizer treatment which gives the highest yields
will be considered the best treatment.

A Fertility Program for Celery Production

The Brown Company, at Shawano Farms, cooperated with the
Everglades Experiment Station over a two-year period (1930-32)
in a comprehensive study of the use of fertilizers for celery
production on sawgrass peat lands. The experimental area
(Area 1 of this report) was located in the southeast corner of
Lot 1 of Section 22 and in the north end of Section 21. This
land had been plowed for the first time in January 1926 and had
been planted successively to potatoes and three crops of peanuts.
During this period the total amount of chemicals which had
been applied to the area as either fertilizers or dusts amounted
to 112.5 pounds of copper sulfate and 12 pounds of zinc sulfate
per acre. No other materials had ever been added.
Sixty-six different fertility treatments were tested upon this
area. Each was used on four separate 1/75 acre plots so scat-
tered through the field that averages of the four plots of any
treatment could be compared to similar averages of other treat-
ments. Tested in these treatments were the influence of the
composition of the fertilizer mixture, the source of the various
fertilizer ingredients, and different methods, time and rate per
acre of fertilizer applications.
Experimental Area 2 was located in Section A of the north-
west sector at the Everglades Experiment Station at Belle Glade.
Originally this land was covered with native sawgrass but after
the excavation of the main canal elder came in on the disturbed
area along the banks of the canal. In June 1924 this land was
ditched, and at this time most of the area was under a heavy
growth of elder, which extended to the native sawgrass in an

Fig. 3.-A field view across the experimental plots in one of the experimental areas.

Florida Agricultural Experiment Station

irregular line near the southern edge of Section A. The land
was subsequently cleared and remained fallow throughout the
winter and spring of 1926. In March 1926 and again in 1927
corn was planted in the area, without any addition of fertilizer.
In September 1927 and again in 1928 the area was divided into
plots and tested for response to manganese, phosphates, potash
and copper, with a variety of different crops. In 1930, after
having received no fertilizer for almost two years, the area was
again divided into plots for a celery fertility experiment. Seven-
teen different fertility treatments were included, each replicated
six times on plots of 1/90 acre each. They were planted to
celery for the first time in the late fall of 1930, and celery was
planted each year thereafter until the final crop was harvested
in the spring of 1936, after which this series of plots was
abandoned and a new series begun in Area 3. Throughout this
period of six years other truck or cover crops were planted after
the celery was removed in the spring but none received addi-
tional fertilizer. Fertilizer was added only for the celery crop.
All celery strippings were removed from this area each year.
Experimental Area 3 was broken out of native sawgrass in
the fall of 1933. This area is located in the south half of
Section D of the southeast sector at the Everglades Experiment
Station. It was moled at a depth of 30 inches throughout, at
an approximate spacing of 15 feet. It was plowed again in the
spring of 1935 and a third time in 1936. From the time it
had been broken in 1933 it had been disked several times to keep
down weed growth, although it was not kept in a continuously
fallow condition throughout this period. The entire area re-
ceived its first fertilizer treatment on January 26, 1937, five
days before the first celery plants were set. This treatment
consisted of a broadcast application of copper, manganese and
zinc sulfates, at rates of 100, 100 and 15 pounds per acre, re-
spectively, over the entire area. The area was divided into
40 plots, consisting of four plots each of 10 different fertility
treatments. The individual plot area was slightly less than
1/30 acre. These different fertilizer treatments were applied
on January 28 and the plants were set the first week in February
for the first celery crop on this area. All strippings from the
plots of this area were turned back to the soil upon which they
were produced.

A Fertility Program for Celery Production

It has been known for years that all plants require small
amounts of several trace elements for satisfactory growth. Of v
these, at least a few are not present in quantities sufficient for
celery in Everglades organic soils. Trace elements which are
known to be low are manganese, zinc and copper, and possibly
boron in some areas. There may be others, but their need has
not yet been satisfactorily demonstrated. Areas 1 and 2 were
used for studies of the effect of trace elements upon celery
Of these trace elements, manganese seems to be the one .
most commonly found deficient in these organic soils with re-
spect to most truck crops. The availability of manganese, like
that of phosphate, is partially dependent upon the degree of
acidity or alkalinity of the soil. However, experiments have
shown that there is an absolute deficiency of manganese in these
soils, regardless of their reaction, inasmuch as celery has shown
a decided response to manganese even on the unburned soils.
Therefore, it is recommended that 100 pounds per acre of man- -
ganese sulfate be applied with the fertilizer to these soils the
first year celery is grown, provided no manganese has been
previously added to the land. For succeeding years much less
will be required and probably 25 pounds per acre should be J
sufficient. Alkaline burned soils will require more than will
the normal soils of the area.
Manganese can be supplied also combined with the bordeaux
sprays which should be applied weekly for the control of early
blight. It is known that this method is satisfactory for some
other crops. It is suggested that four pounds of 83% man-
ganese sulfate be added to 50 gallons of spray solution (5), and
used in this manner for the first three or four weekly sprays
in the event that no manganese is applied with the fertilizer.
It is not desirable to delay the application of manganese until
the plants show a deficiency in the field, since by that time the
plants are already severely injured and will never make the crop
that they would have made had the manganese been supplied
Zinc is another trace element which can be added in fertilizer--
applied to Everglades organic soils. The requirement of celery
for zinc is not large, but the addition of 25 pounds of zinc

Florida Agricultural .Experiment Station

sulfate per acre in the fertilizer, the first year, serves as an
inexpensive insurance against zinc deficiency. In subsequent
years 10 to 15 pounds per acre should be sufficient. As an
/alternative procedure, zinc sulfate (89%) also can be supplied
with the first few bordeaux sprays, at the rate of 2 pounds
per 50 gallons of spray solution. Zinc deficiency has not been
definitely observed with celery on these soils, although there
has appeared to be some response to added zinc, and the response
to zilic of some other crops, such as beans, peas, cabbage, and
potatoes (6) has been quite marked.
The use of copper is not such a problem with celery, inasmuch
as copper is the normal base for bordeaux sprays. However,
work with copper as a plant nutrient has indicated that it must
be present in the soil for benefit to the crop. The first year
that celery is grown on an area it is well to add some snow-form
v bluestone (copper sulfate) along with the fertilizer. One
hundred pounds to the acre should suffice. For subsequent
crops the copper added in the bordeaux sprays will leave suffi-
cient residue in the soil and additional copper need not be added.
Boron is still something of an unknown quantity on Ever-
glades soils where celery is concerned. In other sections of
the state (2) boron deficiency is known to develop as "cracked-
stem" disease, but little celery showing these symptoms has
been reported in the Everglades. Plants require boron in very
small quantities, and since it is known that many fertilizer
materials, such as natural nitrate of soda, triple superphosphate,
and most organic fertilizers (1) contain small amounts of boron,
when-these ingredients are used in the fertilizer there is little
possibility of boron deficiency symptoms appearing. When
synthetic fertilizers are used exclusively in mixing the fertilizer
it might be well. to add 10 to 15 pounds of borax per ton of
fertilizer as an insurance against deficiency of boron. Large
amounts of borax will prove toxic to plants, and are very
According to present knowledge no other trace elements need
be added to these.soils. If others are required, it is probable
that they are present in sufficient quantity as impurities in the
fertilizer materials commonly used. With respect to magnesium,
calcium and iron, there seems to be a sufficiency of these ma-
terials present in these soils natively, at least for several years'
cropping. It is recommended that no further supply of any
of these three be added.

A Fertility Program for Celery Production

Strictly speaking, water is as necessary for plants as is any
material commonly applied through the medium of the soil.
With respect to the absolute quantity required, water can be
considered by far the most important nutrient of all. For this
reason the supply of water available to celery roots is of the
utmost importance and this should be the first factor considered
by the grower.
Since the depth of the water table can be simply regulated
within certain limits on these soils by means of mole drainage
and adequate ditching and pumping, and since water control is
such an important factor with celery, experimental work has
been carried out in which the water table was held at levels
varying from 6 to 30 inches below the surface with several
crops of celery. The resulting data permit the drawing of very
positive conclusions. Except at the time of sowing the seed
and at the time of setting the plants to the field, the water
table should be kept at a depth of from 16 to 24 inches through-
out the entire growing period of the crop. A high water table
shuts necessary soil air from the plant roots and results in
"drowning" the crop, and a very low water table may result
in a water deficiency.

There are, of course, many factors which make it impossible
to present cost data which will fit the growing of a crop in any
location under all conditions or for all seasons. Among these
can be included such factors as the size of the farm, cultural
procedure followed, possible extraordinary invasions of insects
or diseases, and the ability of the grower to deal with specific
problems as they appear.
Nevertheless, in experimental work it is important that the
fertilizer program to be recommended or suggested for field
application be one which produces the highest economical yield.
There is always, with every crop, a point beyond which added
fertilizer produces an increase in yield insufficient to pay for
the application. The only valid way in which this point can be
determined is by estimating, as accurately as possible, the prob-
able cost of producing a crop of celery in the average season.
For this purpose of comparing different fertilizer combinations
in terms of their effects upon yields, a cost break-down is pre-

14 Florida Agricultural Experiment Station

sented in Table 1, which includes all costs attendant upon the
production of a crop under average conditions for the 1937-38


Number of operators ..................................... ................ 4
A cres planted ......... ..... .................... ........................................ 408
Acres harvested ................................................................ .... ... 364
Average yield of harvested acreage (crates) .............................. 448

Per Acre
Cost of Growing Plants:
Rent on land .....................................$ .54
Preparing seedbed ................................................... ........ .. 5.73
Fertilizer ....................... ............................ ............ .86
Seed .............................. ........... 2.90
Applying fertilizer and seeding .......................................... .32
Spraying-including materials ................................. 1.33
Irrigation expense ......... ........... ................... ......... .99
Labor (weeding and covering beds) ...................................... 4.24
Depreciation on seedbed frames and covers ...................... 5.50
M miscellaneous ............................ ...................................... .28

Total ..................................................... $ 22.69
Costs of Growing and Harvesting:
Rent on land ..................................... ...................................$10.91
Growing cover crop .......................................... ................. 3.58
Preparing land for celery .................................................. 6.07
Fertilizer ........................................ 34.77
Applying fertilizer ............................. .................. .86
Transplanting from seedbed to field .................................. 14.03
W after control .......................................... ....... ................... 2.88
Cultivating and weeding .................................................. ...... 11.64
Spraying-including materials ........................................... 16.17
Applying and removing paper ...................................... 11.38
Depreciation on-paper and wire .................................... 9.30
Cutting celery and field stripping .................................... 34.36
Hauling to packinghouse ..................................................... 15.68

Total .............................. .... ... ......... ... $171.63
Cost of Marketing:
Grading ................................................................. ........... $58.24
Pre-cooling. ............ .......... ......... .... ... 35.84
Crates ............................................................ 85.12
Selling ......-...... ........ ............ .................. ........................ 32.70

Total ........................................ ... ............ $211.90

Total cost excluding production interest and operator's
supervision ---............................ .................... $406.22
Returns from celery marketed .......................................................... 487.76
Net returns to operator .............................................................................. 81.54

*Data furnished by R. H. Howard of the Economics Department, Agricultural Extension
Service. University of Florida.

A Fertility Program for Celery Production 15

Detailed cost data for previous seasons, are not available, but
since with expanding future acreage there is little likelihood
that the cost per acre will go up, the data in this table will be
used in making cost comparisons in this bulletin.
Since this experimental work has consisted of comparisons
between several different fertilizer treatments, the cost of fer-
tilizer per acre as reported in Table 1 ($34.77) will be subtracted
and the actual fertilizer costs of the various treatments sub-
stituted. The cost of fertilizing the plants in the seedbeds
has been considered as a constant item for all treatments, and
for this reason, this cost item ($0.86) will not be subtracted
as are the other fertilizer costs. Also, to arrive at a base figure
which will represent the total cash outlay of the grower, all
costs of marketing after delivery to the packinghouse will be
omitted. This basic cost figure is, therefore, $159.55, to which
must be added the cost of the fertilizer.
Actually, since the number of crates per acre influences the
cost of harvesting and hauling somewhat, this basic figure is
probably slightly high for poor yields and slightly low for high
yields. For the purpose of comparison in this bulletin, how-
ever, it will be considered constant.
Table 2 is a very simple table devised and included principally
for convenience in reference. This table shows the influence
of two factors, yield of celery and cost per acre (including fer-
tilizer), upon the actual cost to the grower of each field-trimmed
crate of celery produced. It should be understood that these
costs cover the celery to the point where it has been stripped
in the field, and the cost per crate refers to the cost per
70-pound field crate only. All yield data mentioned in this
bulletin will be given in terms of field-trimmed crates. Addi-
tional trimming at the packinghouse will cause about a 20%
shrinkage in the total number of crates as listed in this table
and referred to in other parts of this bulletin. Costs of washing,
grading, pre-cooling and packing, broker's commission, crates and
shipping, are not included in Table 2. These costs need not be
included, inasmuch as they are taken out of the gross return
before the grower is paid for his produce. The check which
the grower finally receives for his produce represents his total
return, which must more than cover all costs incurred up to
delivery of the crop to the packinghouse, if a net profit is to
be made. For example, assume that the grower sent one acre's
yield of 500 crates of celery to the packinghouse, and received

Florida Agricultural Experiment Station

a check for $250.00 for it. This would give him a return of 50c
a field-trimmed crate for his crop, although further trimming
and repacking at the packinghouse might have reduced to 400
the number of crates actually shipped. Assuming that the total
cost to the above-mentioned grower, including fertilizers, was
$180.00, he should have a net profit of $70.00 per acre, and it is
shown in Table 2 that this celery cost him 36c a crate. If he
had received 50c a field crate for a yield of 350 crates per acre,
with the same field costs, he would have had a net loss of $5.00
an acre. Table 2 can be used to show the yield which must
be obtained at any given field cost to break even or to show a
profit at any return, per 70-pound field crate, from the packing-
It should be obvious that any outside factor, such as a market-
ing agreement which places a restriction upon the percent of
the celery grown which can be shipped, is, in effect, decreasing
the yield per acre, and must be interpreted as such in Table 2.


Despite the fact that available nitrogen is being released in
these peat soils at all times, celery is such a gross feeder that
in no case has a crop been grown at the Everglades Experiment
Station (Areas 2 and 3) that did not show a yield response to
nitrogen fertilizers.
Experiments comparing different materials as sources of ni-
trogen, and for the purpose of finding the amount of nitrogen
which should be added, were conducted in Area 1. It was found
that there was no increase in yield from a fertilizer analyzing
higher than 30% nitrogen when one ton or more was applied
to the acre.
Nitrate of soda, sulfate of ammonia, and castor pomace were
used alone and in various combinations. Over a two-year period
there seemed to be little difference in the source of the nitrogen
supply, whether organic or inorganic. In Area 2, at the Experi-
ment Station, a mixture of half castor pomace and half sulfate
of ammonia proved satisfactory, and in Area 3, a mixture of
sulfate of ammonia and nitrate of soda gave good results. This
latter mixture is to be recommended because of its lower cost
per unit of nitrogen, or, on neutral or slightly alkaline soils,
sulfate of ammonia may be used as the sole source of supply.


No. crates
per acre


Cost per crate when the acre cost of production is:
$140 $150 $160 $170 I $180 I $190 $200 $210
$0.80 $0.86 $0.91 $0.97 $1.03 $1.09 $1.15 $1.20
.70 .75 .80 .85 .90 .95 1.00 1.05
.62 .67 .71 .76 .80 .84 .88 .93
.56 .60 .64 .68 .72 .76 .80 .84
.51 .55 .58 .62 .65 .69 .73 .76
.47 .50 .53 .57 .60 .63 .67 .70
.43 .46 .49 .52 .55 .58 .62 .65
.40 .43 .46 .49 .51 .54 .57 .60
.37 .40 .43 .45 .48 .51 .53 .56
.35 .38 .40 .42 .45 .48 .50 .52
.33 .35 .38 .40 .42 .45 .47 .49
.31 .33 .36 .38 .40 .42 .44 .47
.29 .32 .34 .36 .38 .40 .42 .44
.28 .30 .32 .34 .36 .38 .40 .42
.27 .29 .30 .32 .34 .36 .38 .40
.25 .27 .29 .31 .33 .35 .36 .38
.24 .26 .28 .30 .31 .33 .35 .37
.23 .25 .27 .28 .30 .32 .33 .35
.22 .24 .26 .27 .29 .30 .32 .34
.22 .23 .25 .26 .28 .29 .31 .32
.21 .22 .24 .25 .27 28 .30 .31
.20 .21 .23 .24 .26 .27 .29 .30
.19 .21 .22 .23 .25 .26 .28 .29
.19 .20 .21 .23 .24 .25 .27 .28
.18 .19 .21 .22 .23 .25 .26 .27
.18 .19 .20 .21 .22 .24 .25 .26
.17 .18 .19 .21 .22 .23 .24 .25
.16 .18 .19 .20 .21 .22 .24 .25
.16 .17 .18 .19 .21 .22 .23 .24
.16 .17 .18 .19 .20 .21 .22 .23
.15 .16 .17 .18 .19 .21 .22 .23
.15 .16 .17 .18 .19 .20 .21 .22
.14 .15 .16 .17 .18 .19 .21 .22
.14 .15 .16 .17 .18 .19 .20 .21

$220 1 $230
$1.26 $1.31
1.10 1.15
.98 1.02
.88 .92
.80 .84
.73 .77
.68 .71
.63 .66
.59 .61
.55 .58
.52 .54
.49 .51
.46 .48
.44 .46
.42 .44
.40 .42
.38 .40
.37 .38
.35 .37
.34 .35
.33 .34
.31 .33
.30 .32
.29 .31
.28 .30
.28 .29
.27 .28
.26 .27
.25 .26
.24 .26
.24 .25
.23 .24
.23 .24
.22 .23

.96 mO
.87 .
.80 .
.60 o
.48 ,
.46 0
.40 S
.38 ,
.36 1
.34 0
.33 F-
.25 i

Florida Agricultural Experiment Station

Figure 4 represents comparisons between fertilizers with and
without nitrogen with respect to yields of celery over an eight-
year period at the Everglades Experiment Station. In each
comparison represented the only difference in treatment in the
entire growing period of the crop was in the amount of nitrogen
included in the fertilizer mixture. The smallest response to
nitrogen in the period represented by the graph occurred in
the 1936-37 crop on Area 3. The low yields of this year appar-
ently were caused by two factors-the extremely dry condition
of the surface soil when the plants were set, which necessitated
a resetting of much of the area, and constant rains shortly after
the plants had finally become well established, which kept the
soil water-logged for more than a week. This crop was not set
to the field until early February, and rains were abnormally

Fig. 4.-The influence of a 3% nitrogen fertilizer on the yield of marketable celery
produced per acre for eight crops, on sawgrass peat land. The yield represented by the
figures is given in terms of the number of field-trimmed crates produced per acre. (Yield
data for the five separate years which go to make up the five-crop average in Area 2 are
listed in Table 5 in the appendix.)

The comparison of the 0-41/2-61 vs. the 3-41/-6 with respect
to yields is represented at the extreme left of Figure 4 for the
single year 1930-31. This was a preliminary test and was some-
what modified for the subsequent five-year period.
1 0-4%-6 = 0% Nitrogen, 4 z% P20,, 6% K20.

A Fertility Program for Celery Production

Differences represented by the five-year averages of the sub-
sequent, crops on Area 2 were significant statistically, with
calculated odds of more than 50 to 1. This means that for
every one of these five crops there were striking differences in
yield in favor of the fertilizer containing nitrogen, and that
the average difference for this period was 75 field crates of
marketable celery per acre. Since in this area the nitrogen used
was half from castor pomace [with a cost to the grower of
37.1c per pound of nitrogen (4)] and half from ammonium sul-
fate [with a cost of 9.8c per pound of nitrogen (4)], the total
cost per acre for the nitrogen alone in the 3% fertilizer was
$28.16. All strippings were removed from the plots each year
in this area and the fertilizer was supplied at the rate of 2,000
pounds per acre before planting, with an additional 2,000 pounds
per acre applied later as side-dressing.
The total growing cost per acre, including fertilizer (4), for
each year of this five-year period was as follows for the two
fertilizer combinations used in this comparison:
Without With 3%
nitrogen nitrogen
Growing cost (see Table 1) ............................ $159.55 $159.55
Superphosphate ................................ .... 9.52 9.52
Sulphate of potash ................................... 12.74 12.74
Castor pomace ....... ................... 0 22.28
Sulphate of ammonia .......... ............... 0 5.88
Mixing cost @ $3.50 a ton (4) ............. 7.00 7.00
Total cost per acre .................................. $188.81 $216.97
Comparative average yields, Fig. 4, were 435 and 510 field
crates per acre, respectively, for those two treatments and for
five different crops of celery. The growing cost per field crate
of marketable celery produced (Table 2) was nearly the same
for each of these two treatments. Actually, the cost per crate
without nitrogen was 43.4c, as compared with 42.5c per crate
where nitrogen was used. There were, therefore, 75 crates more
per acre produced where nitrogen was added to the fertilizer,
at a slightly lower cost per crate. If we assume a return to
the grower of 50c per field crate, the total return per acre with-
out nitrogen would be $217.50, with nitrogen $255.00. For the
former the net profit per acre would be $217.50 minus $188.81,
or $28.69. For the treatment with nitrogen the comparable
net profit would be $255.00 minus $216.97, or $38.03. Nitrogen
in the fertilizer would, therefore, increase the net profit per
acre by $9.23, assuming a return of 50c per field-trimmed crate.

Florida Agricultural Experiment Station

This is a return of approximately 33% on the investment of
the nitrogen in the fertilizer. A higher return per field crate
(as in 1937-38, Table 1) would mean a greater difference be-
tween the profits realized from the two treatments, and, con-
versely, a lower return would tend to minimize the treatment
differences from the economic standpoint.
The other three comparisons shown in Fig. 4 are for one-year
yields only and are, therefore, not so dependable as are the fig-
ures for the five-year average. For the 1930-31 crop, mentioned
briefly -above, a total of only 2,000 pounds of fertilizer per
acre was used, one-half before planting and one-half as a side-
dressing. This was a good year for celery, as can be seen from
the yields obtained. The same materials were used in the fer-
tilizer as outlined in the discussion of the five-year yields, but
with the amount of fertilizer used only one-half as large, the
crop costs per acre were slightly lower, being $174.23 without
nitrogen and $188.26 with nitrogen. Respective yields were 601
and 685 field-trimmed crates per acre, which give a growing
cost per crate of 29.0c for the former and of 27.5c for the latter.
It is obvious that the nitrogen added in the latter treatment
proved an excellent investment, since this treatment not only
produced 84 more crates per acre but reduced production costs
11/2c per crate. Assuming, as above, that the grower received
a return of 50c a field-trimmed crate, the net profit per acre of
celery for the year would have been $126.27 without nitrogen
and $154.24 with nitrogen. The return ($27.97> from an in-
vestment of $14.08 worth of nitrogen fertilizer in this case
would be almost 200% for this year, with the celery selling at
50c per field-trimmed crate.
The 1936-37 crop, Figure 4, has been already mentioned with
respect to unfavorable conditions for production. Yields were
very low with both treatments, the treatment containing nitro-
gen yielding but five crates per acre more than the one without.
This was the first crop grown in Area 3 and was fertilized with
2,000 pounds per acre before planting and another 2,000 pounds
as side-dressing; formulas used were 0-6-12 and 3-6-12. The
nitrogen was supplied in the latter as half sulfate of ammonia
and half nitrate of soda, which lowered considerably the nitro-
gen cost in comparison to that in Area 2 in the previous year
already discussed, since the State Chemist's quotation on the
nitrogen in nitrate of soda is 12.4c per pound (4). Other
materials were the same as those used in Area 2. The field

A Fertility Program for Celery Production

cost for growing this crop was $188.41 without nitrogen and
$201.73 per acre with nitrogen. From Table 2 it can be seen
that the cost per crate of celery was approximately 64.5c for
the former and 67.9c for the latter. With a 50c per crate return
for the celery, it is obvious that a net loss would be incurred
from both treatments, and despite the five-crate difference the
loss from the treatment in which nitrogen was added would be
heavier. With a 70c return per crate both treatments would
have shown slight profits but under no probable market condi-
tions could the nitrogen have paid for itself. This has been
the only crop of the eight grown at the Experiment Station in
which the addition of nitrogen fertilizer has not yielded an
economically profitable return at 50c per field-trimmed crate
for the increased yield obtained.
The year 1937-38 was, by contrast, a fine year for celery,
as is indicated by the yields represented in Fig. 4. The strip-
pings of the previous year's crop had been returned to the soil,
and as a consequence only one ton of fertilizer was used, all
applied before planting. The costs per acre were somewhat lower,
being $173.98 without nitrogen and $180.64 with nitrogen. The
cost per field-trimmed crate is found to be 19.3c for the former
treatment, with a yield of 903 crates per acre, and 18.9c per
crate for the latter, with a yield of 958 crates per acre. Almost
any return will net a considerable profit under these conditions
but the latter treatment, with a higher yield per acre as well
as a slightly lower cost per crate than the former, is undoubtedly
an economically sound fertilizer treatment. Actually, the 1937-
38 season found marketing agreement restrictions in effect, so
that the full yield could not be marketed.
In summing up the effects of nitrogen in fertilizer, it has_
been found that in eight successive years fertilizer mixtures
containing phosphate and potash plus 3% nitrogen have given
higher yields than fertilizers of the same potash and phosphate
content without nitrogen. These yield responses to nitrogen re-
sulted whether all of the fertilizer was applied before planting
or whether 1fart was applied as a side-dressing. In seven of
these eight years the increased yield due to added nitrogen
was sufficient to more than pay the cost of nitrogen, at the very
conservative estimated value of 50c per field-trimmed crate.
Therefore, a total of 60 pounds per acre of nitrogen, applied
with the necessary phosphate and potash before the plants are
set, is the suggested procedure for commercial celery growing

Florida Agricultural Experim't Station

in the Everglades on sawgrass peat lands. Mixtures of sulfate
of ammonia and nitrate of soda, or either of these alone, should
be suitable nitrogen sources, from the standpoint of both cost
and returns.

Natively, these soils are very low in potassium. It is, there-
fore, of the utmost importance that both the amount and the
source of potash best for celery be determined. With respect
to source, it was found in Area 1 that sulfate of potash, muriate
of potash, and hardwood ashes were all acceptable as potash
fertilizers. Kainit showed up well one year but poorly another.
According to the 1937 State Chemist's report (4), these ma-
terials cost the grower as follows:
Sulfate of potash ........................ 5.31c per pound of K2O
Muriate of potash ...................... 3.83c per pound of KO2
Kainit ............. ................ 6.25c per pound of KLO
3% Hardwood ashes .................... 35.00c per pound of K2O
The excessive cost, per pound of K20, makes hardwood ashes
far too expensive for general use, although if available in quan-
tity they are a fine fertilizer material. Kainit also is relatively
expensive per pound of potash and this, together with the un-
certainty attached to its results, makes it a less desirable
fertilizer than the other two potash salts. For this reason only
the muriate and the sulfate of potash were used with celery in
the trials at the Experiment Station.
Figure 5 illustrates a comparison between these two materials.
As a five-year average the muriate of potash produced 51 crates
per acre per year more than did the sulfate. All in all, using
results of two years in Area 1, six years in Area 2, and two
years in Area 3 (a total of 10 separate crop comparisons), the
muriate of potash plots outyielded the sulfate of potash plots
in seven cases. Statistically these differences are not considered
significant (the statistical odds for the five-year average from
Area 2 were 5 to 1), but from the practical standpoint it is
clear that, because of the difference in cost of the two materials,
muriate of potash has proven preferable to the sulfate for celery.
With regard to the quantities of potash which must be sup-
plied, it was found that with the first celery crop grown on
each of the three areas a relatively low amount of potash was
required (a 6 to 8% potash analysis fertilizer, applied broad-

A Fertility Program for Celery Production 23

cast at the rate of one ton per acre before planting gave good
results). With all subsequent crops larger amounts of potash
were required. This difference between the first and other years
is probably only the result of a partially adequate reserve supply
of potash in previously uncropped soils, or of previous cropping
with a crop which removes relatively less potash than does

I... .. v m,.' -
-_ t= ..>- .;

tA m o --.t b s

Ar-ea "Z.- Q -,r

of celery, per acre, over an eight-year period. For each comparison the amounts of potash
(KO) applied were the same. The yield represented by the figures is given in terms of
the number of field-trimmed crates produced per acre. (Yield data for the five separate
years which go to make up the five-crop average in Area 2 are listed in Table 6 in the

It may be readily seen from Figs. 6, 7 and 8 that celery
grown without potash will be practically a failure on these
soils. From the economic standpoint this possibility is further
500- "-" i -. ..

emphasized-for the five-year average period covered by Table 3
a return of 65c a crate would have been necessary for the grower
to break even with celery for this period, in the event that he
fertilized only with phosphate. The data comprising Table 3
were calculated in the same way that similar data were treated
in the previous section on nitrogen fertilizers. It should be
remembered that both yield per acre and cost and return figures
are based upon field-trimmed cratates, rather than crates as
actually shipped from the packinghouse.
Sea-o *r

Florida Agricultural Experiment Station

".n _l lll. .

400- 54)
300- (246)
200 -
100 -

A l -- .9 "

Fig. 6.-The influence of different amounts of potash (KaO) fertilizers on the yield of
marketable celery produced per acre for two crops grown on Area 1. The yield represented
by the figures is given in terms of the number of field-trimmed crates produced per acre.

Fertil- Yield Cost Total Re-i
Treatment izer per Cost per per I turn per Net Profit
Number Formula' Acre2 Acre3 Crate Acre' j per Acre

A-1 0-0-0 174 $159.55 $0.92 $ 87.00 -$72.55 (loss)
A-2 0-0-6 352 179.29 .51 176.00 3.29 (loss)
B-1 0-4%-0 222 176.07 .79 111.00 65.07 (loss)
B-2 0-4%-6 435 188.81 .43 217.50 + 28.69
B-3 0-4%-12 538 201.55 .37 269.00 + 67.45
C-1 0-9-6 466 198.33 .43 233.00 + 34.67
C-2 0-9-12 536 211.07 .39 268.00 + 56.93

'One ton applied at planting, one ton applied later as side-dressing.
'Calculatel as of 70-lb. field-trimmed crates of marketable celery produced per acre.
3Including cost of fertilizer materials, cost of mixing fertilizer @ $3.50 a ton, and all
field costs up to and including stripping and field grading.
'Assuming a return to the grower of 50c per field-trimmed crate, after all packinghouse
charges, brokerage fees, freight costs, etc., have been deducted.

The yield data represented in Figure 7 and listed in Table 3
are all based on five-year average harvests. The comparisons
included show differences between comparable treatments which
have been calculated to be highly significant statistically, with
odds greater than 50 to 1 in all comparisons. Figures 6 and 8
are presented to show the lower potash requirement which was
found for the first celery crop in these areas, and also serve
to emphasize the importance of potash fertilization. They would

A Fertility Program for Celery Production

seem also to indicate that in good celery years, such as 1931-32
and 1937-38, a fertilizer analyzing even higher than 12% potash
applied at the rate of one ton to the acre before planting (more
than 240 pounds of K20 per acre) might be beneficial, but a
later discussion of the yields from Area 2 will show that a
higher application will probably not be advantageous from the
commercial standpoint in the average year.

600 -

500 -
400 -
o00 -
00 (174)

100 I

No P 65
No pc,0O

I 43bJ

ht 62. .IO5
4:-: Pr05l

Fig. 7.-The influence of different amounts of potash (K2O) fertilizers on five-year
average yields of marketable celery produced per acre on Area 2 at the Everglades Experi-
ment Station. The different amounts of potash applied were tested at each of three levels
of phosphate (PaOs). The yield represented by the figures is given in terms of the number of
field-trimmed crates produced per acre. (Yield data for the five separate years for all of these
comparisons are listed in Table 7 in the appendix.)

Fig. 8.-The influence of different amounts of potash (KzO) fertilizers on the yield of
marketable celery produced per acre for two crops grown on Area 8. The different amounts
of potash applied were tested at each of three levels of phosphate (PsOs). The yield repre-
sented by the figures is given in terms of the number of field-trimmed crates produced
per acre.


go %gO
9% 1aOs

Florida Agricultural Experiment Station

Table 3 has been included to emphasize the economic advant-
age of the use of potash fertilizers for celery. Here, as in the
discussion of nitrogen fertilizers, the cost of the fertilizer was
taken from the 1937 report of the State Chemist (4), the
standard mixing charge has been added, and the total added
to the basic figure found previously to represent the costs of
carrying celery through to the field-trimmed crate, all on the
"per acre" basis. The rate was one ton of fertilizer to the acre
applied before planting and one ton per acre as side-dressing
when the crop was partly grown. The cost of both tons has
been included, although it has been found that in the event strip-
pings are not removed from the field the fertilizer added as
side-dressing would not have been necessary. The advisability
of such a procedure is discussed in the latter part of this bulletin.
Returning to the discussion of Table 3, again it has been
assumed that the marketable celery brought a gross return to
the grower of 50c per field-stripped crate, in order to compare
the several treatments listed from the standpoint of net profits
per acre. With respect to each or any comparison in this table,
the treatment higher in potash has produced the crop with the
lower cost per crate. Under any probable market conditions
such a condition must make the use of the higher potash analysis
fertilizers economical. For this reason the use of 12% potash
fertilizers, properly mixed with nitrogen and phosphate, is sug-
gested for commercial practice, under conditions comparable to
those under which these crops have been grown.
Table 3 does not list any 15 or 18% potash fertilizers and
it might be assumed, as mentioned above, that because of the
other comparisons an analysis higher than 12% might prove
economically feasible when applied at the same rate (one ton)
per acre. No 0-41/2-18 fertilizers were tested in Area 2. How-
ever, a fertilizer with the approximate analysis of 0-12-18 was
included in the experiment. In three of the five years this
treatment outyielded the 0-4/2-12 by 3, 21 and 27 crates per
acre, while in the other two years the 0-4-12 outyielded the
0-12-18 by 3 and 16 crates per acre. No significance can be
attached to such irregular results. It is also most unlikely
that the extra phosphate depressed the yields.
Thus it can be seen that the 6% potash fertilizer produced
a tremendous yield response from celery compared with that
produced by a fertilizer entirely deficient in potash; that a 12%
potash fertilizer produced a relatively smaller but still sizeable

A Fertility Program for Celery Production

increase in yield over that of the 6% fertilizer; and finally, that
an 18% potash fertilizer produced a slightly higher yield in
three out of five years than did the 12% formula, but not enough
higher, in the average year, for the yield increase to pay for
the additional potash applied per acre. This can serve to
illustrate the economic law of diminishing returns as applied
to fertilizer usage.
From the standpoints of both yield and net profit per acre,
therefore, a fertilizer analyzing 12% potash, properly balanced
with nitrogen and phosphate, is suggested for celery. The ratio
of nitrogen to potash which has given best results has been
found to be 1 to 4. The ratios of phosphate to the other two
nutrient materials will be discussed in the next section. Muriate
of potash is recommended as the most economical potash source,
although sulfate of potash and hardwood ashes are suitable in
all respects except their higher cost per unit of potash.

These peat and muck soils are also very low in phosphates,
perhaps even lower than in natural potash content. Further-
more, the availability of phosphate to celery-or to any other
plant-is dependent upon other factors, largely the reaction and
calcium content of the soil. At the normal soil reactions usually
found in this region (slightly acid to slightly alkaline) part of
the phosphate forms a relatively insoluble compound with cal-
cium or with some other soil constituent, and thus becomes less
available to the plant roots.
Many sources of phosphatic fertilizers are used and varied
results may be expected on different types of soils. In Area 1
of these experiments several phosphate sources were compared,
including 16% superphosphate, colloidal phosphate, floats, for-
eign basic slag, and domestic basic slag. Of these, floats and
colloidal phosphate were found to be definitely unsatisfactory
materials, regardless of cost. The other materials all were
more or less satisfactory, the domestic basic slag in particular
showing up well. However, it is practically impossible to com-
pare these basic slag materials with the superphosphates on
the unit P20s basis, because of a rather wide variability in the
phosphate content of slags from various sources, and because
the guaranteed analyses of the slags are usually much lower

Florida Agricultural Experiment Station

than the actual available phosphate content. The basic slags
also contain from 1 to 3% of manganese oxides, and since
manganese is also very low in these soils it is impossible to
tell how much of the yield difference is due to the source of
phosphate and how much to the various trace elements present
in the slag. In general, basic slag is well suited to unburned
soils and less suited for use on alkaline soils. Should home
mixing of fertilizer be practiced, ammonia fertilizers should
not be mixed with basic slags, or some of the ammonia will
be lost.
. The superphosphates, "single" or "triple", can be used more or
less interchangeably. Triple superphosphate is slightly cheaper
per unit of P205 (4), and more economical, higher analysis fer-
tilizers can be mixed when this material is used. These are
probably the most satisfactory phosphatic materials on neutral
or alkaline soils, and they have proven very satisfactory on the
slightly acid soils of the Everglades Experiment Station. The
available phosphoric acid (P205) has a cost of 5.5c per pound
in 16% superphosphate, and of 5.1c per pound in 44% super-
phosphate, according to the State Chemist's report (4).

600 -63

(5 ,C, )
400 (.35) B !,

-0 (17I

5CNO No B ^B r'*H ^

"o .. o o 1o--2 0

Fig. 9.-The influence of different amounts of phosphate (PzOs) fertilizers on five-year
average yields of marketable celery produced per acre on Area 2 at the Everglades Experiment
Station. The different amounts of phosphate applied were tested at each of three levels of
potash (KzO). The yield represented by the figures is given in terms of the number of
field-trimmed crates produced per acre. (Yield data for the separate years for all of these
comparisons are listed in Table 8 in the appendix.)

Figure 9 represents the yields of marketable celery, in terms
of the number of 70-pound field-trimmed crates per acre, pro-
duced by using different quantities of superphosphate in the

A Fertility Program for Celery Production

fertilizer. Since it was found that a 12% potash fertilizer,
applied at the rate of one ton per acre prior to setting the plants
to the field was, on the average, best for celery, the comparison
on the extreme right in the figure tells the story with respect
to phosphate requirements of this crop. Over a five-year period
the 9% phosphate formula, at a cost of about $9.50 an acre
more than that of the 41% fertilizer, actually gave a slightly
reduced annual yield. However, the first two years of this
period the 9% analysis fertilizer gave higher yields than did
the 41/2%, which indicates that a soil reserve was built up
by the third year which served to make the 41/9% analysis
fertilizer sufficient thereafter. The "fixing" of the phosphate
in the soil in a relatively insoluble form undoubtedly has some
effect upon these results. It is probable that a 6% material
would be satisfactory, and perhaps more economical than a
change from a 9 to a 41/2% fertilizer material at the start of
the third year on celery land.

SFertil- Yield Cost I Total Re-
Treatment izer per Cost per per turn per Net Profit
Number Formulal Acre2 Acre3 Crate Acre' per Acre
A-1 0-0-0 174 $159.55 $0.92 $ 87.00 -$72.55 (loss)
A-2 0-4%-0 222 176.07 .79 111.00 65.07 (loss)
B-1 0-0-6 352 179.29 .51 176.00 3.29 (loss)
B-2 0-4%-6 435 188.81 .43 217.50 + 28.69
B-3 0-9-6 466 198.33 .43 233.00 + 34.67
C-1 0-4%-12 538 201.55 .37 269.00 + 67.45
C-2 0-9-12 536 211.07 .39 268.00 + 56.93

'One ton applie I at planting, one ton applied later as side-dressing.
2Calculated to the number of 70-lb. field-trimmed crates of marketable celery produced
per acre.
3Including cost of fertilizer materials, cost of mixing fertilizer @ $3.50 a ton, and all
field costs up to and including stripping ani field grading.
'Assuming a return to the grower of 50c per field-trimmed crate, after all packinghouse
charges, brokerage fees, freight costs, etc., have been deducted.

Inasmuch as cost data for potash and nitrogen materials
required a more comprehensive analysis than has proven neces-
sary with phosphate fertilizers, Table 4 is included principally
for reference and for convenient comparison. The economic
value of a 41/ % phosphate formula should be evident from
this table. The preceding paragraph suggests the use of a 6%
phosphate fertilizer, rather than a 41%, but this difference
is of minor importance, and would depend upon the previous

Florida Agricultural Experiment Station

history of the land to be planted. In Area 3 this 6% formula
has proven desirable up to this time.
To sum up the effects of phosphate fertilizer briefly, then,
either single or triple superphosphate should be suitable, but
on unburned lands domestic basic slag may be even better.
A 6% phosphate fertilizer, properly balanced with nitrogen
and potash, applied at the rate of one ton to the acre before
setting the plants on land to which the strippings of previous
crops have been returned, is probably about optimum for Ever-
glades organic soils to be cropped annually with celery. The
final ratio of these fertilizer materials suggested for commercial
use is 1:2:4 (nitrogen, phosphate and potash).
The method of applying fertilizers has been found to be some-
what dependent upon the rate of application, so that these two
factors are probably best discussed together.
Fertilizers applied in considerable quantity in a band below
the roots may "burn" the young roots unless applied several
days before the plants are set. Experiments have shown that\
celery in the Everglades, planted in 30-inch rows, four inches
apart in the row, gives growth response to fertilizer applied
broadcast before planting as high as or higher than to a similar
quantity of fertilizer applied in a band beneath the row, pro-
vided a suitable analysis fertilizer is used at a rate of 2,000
pounds per acre. The 3-6-12 formula evolved and presented in
the previous sections of this paper is such a fertilizer. Broad-
casting (or distribution with a seed drill) is satisfactory for
celery because of the tremendous spread of root growth of
celery in these organic soils, and because very little fertilizer
is lost by leaching processes during the winter months. The
celery roots are continually growing into fresh soil which holds
an additional supply of fertilizer. Therefore, no side-dressing
need be applied to celery in a normal year on these soils. There
has been found to be no response to side-dressing applications
when enough fertilizer was applied before planting to carry the
crop through to harvest. Only when this original application
of fertilizer was too low did the celery respond to side-dressing,
and then it never produced as high yields as it did when it
had an ample amount of fertilizer from the start. When side-
dressings were applied in treatments discussed in the earlier
pages of this bulletin, the cost of the fertilizer was included

A Fertility Program for Celery Production

in the cost per acre for growing the crop, but in many cases
in which both the formula and the rate per acre applied before
the plants were set were suitable, the chief benefits from the
side-dressing was only to add to the fertilizer reserve of the
soil, and considerable amounts of it were undoubtedly lost by
leaching during the summer months.
The previous history of the soil is, therefore, a factor affect-
ing the rate of fertilizer application. In virgin land it has
been found that a fertilizer analyzing 3% nitrogen (half from
nitrate of soda, half from sulfate of ammonia), 6% P20s (from
superphosphate or basic slag) and 6 to 12% K20 (from muriate
or sulfate of potash) should be applied at the rate of two tons
to the acre, broadcast. With land previously cropped and fer-
tilized for crops other than celery, a fertilizer having the formula
3-6-12 should be applied at the same rate and in a similar man-
ner.' For succeeding years, experiments have shown that for -
the average year one ton per acre of the 3-6-12 should suffice
for the entire growing period of the crop, when the previous
crop has been stripped in the field and the strippings retained
on the land. In the event that pink rot has shown up in the
field it may not prove advisable to return the strippings to the
soil, and there is experimental work under way at this time
to determine the advisability of returning the strippings under
these conditions.! If the strippings are removed from the field
for sanitary reasons it is advisable to continue the use of the
3-6-12 fertilizer at a rate of approximately 3,000 pounds per
acre per year. It has been found that with a crop yielding 500
crates of marketable celery per acre, about 40% by weight of
the plant is represented by strippings. With higher yielding
crops, this percentage is somewhat lower, and with low yield-
ing ones it is, of course, somewhat higher. On the average,
however, it is estimated that 50% of the fertilizer taken up
by the crop can be returned to the soil in the form of the strip-
pings and roots, and under such conditions, one ton of 3-6-12
should be sufficient additional fertilizer for the succeeding celery
crop. I Another factor which makes possible this lower applica-
tion in succeeding years is the residue of potash and phosphate
which is left in the soil despite summer leaching.
As mentioned above, !experimental evidence indicates that on
these peat soils all of the fertilizer can be applied before the
plants are set (no side-dressing necessary), and it is recom-
mended that it be applied broadcast or by drill and disked and

Florida Agricultural Experiment Station

floated in at least three days before the plants are set. How-
ever, if the weather should be unseasonably wet and cold in
the growing season, some further side-dressing with nitrogen
might be beneficial. It is suggested that this side-dressing con-
sist of nitrate of soda or nitrate of potash on normal, unburned
soils, or of sulfate of ammonia on neutral or slightly burned
soils, applied at approximately 200 pounds to the acre. It should
not be worked in deeply, because of the mass of roots near the
surface of the soil. Assuming that the celery field is adequately
mole-drained and that water does not stand on it, this side-
dressing should be applied as soon as the water from the un-
seasonable rains has subsided and the field is workable.

Celery should not be planted on raw land. The first year
that sawgrass soils are broken it is better to plant them to some
crop of low fertility requirements. Sawgrass decomposes rather
slowly, and during the process of decomposition crops requiring
large amounts of fertilizer will not do well.
Although seedbeds are commonly raised two to three inches
to permit rapid surface irrigation, it is neither necessary nor
desirable to set the celery in the fields upon raised beds in the
Everglades area. Celery is commonly planted in rows 30 inches
apart, and with a four-inch spacing between plants. Under
such conditions, there will be approximately 52,275 plants to
the acre. The relatively close spacing usually will prevent pro-
duction of too many extra large stalks, will encourage erect
stalks with good hearts, and will give a high per acre yield.
The distance between rows is commonly modified somewhat
for convenience in spraying, depending upon type of equip-
ment used.
With regard to celery varieties, only the so-called self-
blanching types are grown. Selected strains and especially
bred varieties of celery are being introduced almost yearly by
the seed houses. Some of these "specials" have done very well,
and almost all of them are improvements over the old Golden
In all of this experimental work the only filler used with
the fertilizer mixtures was sawgrass peat soil. Consequently
the filler may be ignored completely in a consideration of the
active ingredients of the fertilizer mixtures. In the event that
the grower mixes his own fertilizer, or has it mixed to his order,

A Fertility Program for Celery Production

a slightly higher analysis fertilizer, applied at a lower rate per
acre, may be used. It should be remembered that with more
concentrated fertilizers it is most important that the mixing
be very thoroughly done. Since the ratio of N:P20s:K20 sug-
gested for use has been 1:2:4, it is possible to have mixed a
4-8-16 fertilizer for application at the rate of 1,500 pounds per
acre, in place of the 3-6-12 application at 2,000 pounds. On
new lands being set to celery for the first time, this would
mean an application of 3,000 pounds of 4-8-16 instead of 4,000
pounds of 3-6-12. This 4-8-16 mixture would be composed of
251 pounds of nitrate of soda (16% N), 197 pounds of sulfate
of ammonia (20.5% N), 365 pounds of triple superphosphate
(44% P205), and 533 pounds of muriate of potash (60% K20),
plus the necessary filler to make the ton of fertilizer. The
essential trace elements, in recommended amounts, can be used
to replace part of this filler.
If it is desired to withhold the nitrogen application and apply
it as a side-dressing, an 0-12-24 mixture can be used at the
rate of 1,000 pounds per acre before the plants are set, and the
nitrogenous materials distributed later as a side-dressing.

The experimental data which have been discussed in the body
of this bulletin permit the presentation of the following com-
bination of suggested fertility programs for the commercial
growing of celery on the sawgrass peat lands of the Florida
1. For virgin sawgrass peat soils.
Do not plant virgin soils to celery the first year the land
is broken. Work the land into some semblance of shape,
planting a crop of low fertilizer requirement the first year.
This will give the turned under sawgrass a chance to decom-
pose thoroughly.
The second year apply broadcast 4,000 pounds to the acre
of a 3-6-6 or a 3-6-12 fertilizer (or its equivalent in a higher
analysis fertilizer of the same relative composition), to which
has been added -100 pounds of manganese sulfate, 100 pounds
of copper sulfate, and 25 pounds of zinc sulfate. The nitro-
gen should be applied as one half sodium nitrate and one half
ammonium sulfate if the soil is normal and unburned. or
entirely as ammonium sulfate if the soil is neutral or slightly
burned. The phosphate should be applied as the triple super-
phosphate or as basic slag. The use of the latter material
will result in a lower analysis fertilizer which will conse-

Florida Agricultural Experiment Station

quently have to be applied at a higher rate per acre. If
basic slag is used, ammonium sulfate should not be used
as the nitrogen source. The potash should be applied as
the muriate, although either the sulfate or hardwood ashes
are quite suitable if they are on hand.
-This fertilizer application should be made not less than
three days prior to the setting of the plants, and should be
disked and floated to mix the soil and fertilizer, and to level
the field for planting.
2. For sawgrass peat soils which have been previously fertilized
and planted to truck crops other than celery.
Apply broadcast 3,000 pounds of a 3-6-12 (or its equiva-
lent) fertilizer composed of the same materials mentioned
above and in a manner similar to that suggested above. If
copper sprays or dusts have been used on the previous crops,
or if copper has been added to fertilizers previously used
on the land, no copper need be applied. Otherwise, add 100
pounds of copper sulfate with the fertilizer. If manganese
has been previously added to the soil, apply only 25 pounds
per acre of manganese sulfate. If no manganese has been
used previously, 100 pounds per acre should be added. If
zinc has been used previously, 10 to 15 pounds of zinc sulfate
should be sufficient. If none has been used before, 25 pounds
per acre, applied with the fertilizer, is suggested.
3. For sawgrass peat soils previously fertilized for and planted
to celery.
If either of the programs suggested above, or their ap-
proximate equivalent, had been followed the previous year,
and if the celery strippings had been returned to the soil
and no market crop grown since the previous celery crop,
it is suggested that 2,000 pounds of a 3-6-12 (or its equiva-
lent) fertilizer per acre be applied broadcast, plus 25 pounds
of manganese sulfate and 10 to 15 pounds of zinc sulfate
per acre. If the strippings of the previous crop had been
removed, or if the previous year's celery crop has been fol-
lowed by another market crop, 3,000 to 4,000 pounds of the
same formula fertilizer will probably be required for a good
crop of celery.
The above three suggested programs should not require the
use of additional side-dressing in a normal winter season. If
unseasonably wet and cold weather occurs at some time during
the growing period, it is suggested that a side-dressing of 200
pounds per acre of nitrate of soda or nitrate of potash be applied
to unburned soils, or 200 pounds per acre of sulfate of ammonia
to neutral or slightly alkaline burned soils. This should not be

A Fertility Program for Celery Production

worked in deeply, since many of the roots of celery grow near
the surface.
It should not be necessary to add lime or dolomite (calcium
or magnesium) to these soils at any time. Boron deficiency
does not commonly occur on Everglades soils; however, if such
a condition is suspected, the addition of 10 to 15 pounds of
borax per acre should suffice and will not be dangerous if it
is properly distributed.
These recommendations are based primarily upon experi-
mental work on sawgrass peat soils. For heavier muck soils
of the Everglades area no positive recommendations can be
made because of lack of experimental data, but it is suggested
that a somewhat similar program be followed, substituting a
fertilizer slightly higher in phosphate, such as a 3-8-12. The
more highly mineralized soils seem to have a higher phosphate
requirement with most truck crops than do the highly organic
A brief discussion of the common cultural procedure for celery
growing in the area is included in the body of the bulletin. The
most important features of such a procedure are the weekly
application of bordeaux sprays (in which the necessary zinc
and manganese may also be added, instead of in the fertilizer),
and the maintenance of a suitable water table during the grow-
ing season,. from 16 to 24 inches below the soil surface.
The fertilizer program suggested has been shown to be eco-
nomically sound on the sawgrass peat soils of the Everglades
Experiment Station, assuming a return to the grower of 50c
per 70-pound field-trimmed crate of marketable celery. This
program is intended to serve as a base for commercial plantings
on comparable soils, but since there is some land variation
throughout the area, it is suggested that the grower try varia-
tions of the program based upon his previous experience with
celery or other crops on his own land, keeping an actual cost
and return record. It is only by such means that the most
economical procedure for celery growing on any piece of land
can be determined.
The author is indebted to Dr. R. V. Allison, the late H. H. Wedgworth
and the late Dr. A. Daane for much of the planning of this experimental
work; and to Dr. G. R. Townsend, Mr. Wedgworth and R. E. Robertson
for their close attention to and detailed records of many of the earlier
crops grown.

36 Florida Agricultural Experiment Station


1. GADDUM, L. W., and L. H. ROGERS. A study of some trace elements
in fertilizer materials. Fla. Agr. Exp. Sta. Bulletin 290. 1936.
2. PURvIS, E. R., and R. W. RUPRECHT. Cracked stem of celery caused
by a boron deficiency in the soil. Fla. Agr. Exp. Sta. Bulletin 307.
3. SCRUGGs, F. H. Annual fruit and vegetable report. Fla. State Mkt.
Bureau. Season 1937-38.
4. TAYLOR, J. J. Annual report of the State Chemist of Florida for the
year ending December 31, 1937.
5. TOWNSEND, G. R. Manganese sulphate sprays for vegetable crops.
Fla. Agr. Exp. Sta. Press Bulletin 487. 1936.
6. TOWNSEND, G. R. Zinc sulphate sprays for vegetable crops. Fla.
Agr. Exp. Sta. Press Bulletin 488. 1936.
7. WANN, JOHN L. Florida truck crop competition. II. Intrastate.
Fla. Agr. Exp. Sta. Bulletin 238. 1931.

A Fertility Program for Celery Production



Fertilizer Formula 0-4/2-6 3-4%-6 Increase Due
Sto Nitrogen

1932 238 255 17
1933 496 559 63
1934 351 386 35
1935 756 840 84
1936 335 512 177

Total 2,176 2,552 376

Five-year average 435 510 75


rPotash SourceI Increase Due
Muriate I Sulphate | to Muriate

1932 306 294 12
1933 652 556 96
1934 422 390 32
1935 1,044 1,058 14
1936 521 393 128

Total 2,945 2,691 254

Five-year average 589 538 51

Florida Agricultural Experiment Station


I No Phosphate

Year Fertilizer Formula Increase Due
0-0-0 (Check) | 0-0-6 to Potash

1932 20 154 134
1933 231 366 135
1934 158 271 113
1935 317 655 338
1936 144 315 171
Total I 870 1 1,761 ] _891_
Five-year average | 174 | 352 178

II 4'2/% Phosphate

Year Fertilizer Formula Increase Due
0-4Y2-0 0-41/2-6 to Potash
1932 58 238 180
1933 288 496 208
1934 180 351 171
1935 415 756 341
1936 171 335 164
Total 1,112 j 2,176 1,064
Five-year average | 222 | 435 213

SIncrease Due
Year Fertilizer Formula to Extra
0-4I2-6 0-42-12 Potash

1932 238 294 56
1933 496 556 60
1934 351 390 39
1935 756 1,058 302
1936 335 393 58
Total 2,176 2,691 515
Five-year average 435 538 | 103

III 9% Phosphate

Year Fertilizer Formula Increase Due
0-9-6 0-9-12 to Potash

1932 245 303 58
1933 520 594 74
1934 352 389 37
1935 877 1,001 124
1936 338 394 56
Total 2,332 2,681 | 348
Five-year average | 466 I 536 70

A Fertility Program for Celery Production


I No Potash

Year Fertilizer Formula Increase Due
0-0-0 (Check) I 0-41-/-0 to Phosphate

1932 20 58 38
1933 231 288 57
1934 158 180 22
1935 317 415 98
1936 144 171 27
Total 870 | 1,112 | 242
Five-year average 174 | 222 I 48

II 6% Potash

Year Fertilizer Formula Increase Due
0-0-6 0-41/-6 to Phosphate

1932 153 238 84
1933 366 496 130
1934 271 351 80
1935 655 756 101
1936 315 335 20
Total 1,761 | 2,176 415
Five-year average 352 435 83

SIncrease Due
Year Fertilizer Formula to Extra
0-412-6 0-9-6 Phosphate

1932 238 245 7
1933 496 520 24
1934 351 352 1
1935 756 877 121
1936 335 338 3
Total 2,176 2,332 156
Five-year average 435 466 31

III 12% Potash
I Increase Due
Year Fertilizer Formula to Extra
0-41/2-12 I 0-9-12 Phosphate

1932 294 303 9
1933 556 594 38
1934 390 389 1
1935 1,058 1,001 -57
1936 393 I 394 1
Total 2,691 2,681 -10
Five-year average 538 | 536 2