• TABLE OF CONTENTS
HIDE
 Historic note
 Main














Group Title: Research Report - University of Florida Central Florida Research and Education Center ; 85-15
Title: Carrot fertilization trials at Zellwood, Florida, 1976-79
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00075871/00001
 Material Information
Title: Carrot fertilization trials at Zellwood, Florida, 1976-79
Series Title: Research Report - University of Florida Central Florida Research and Education Center ; 85-15
Physical Description: Book
Creator: Forbes, Richard Brainard
Publisher: University of Florida, Central Florida Research and Education Center
Publication Date: 1985
 Record Information
Bibliographic ID: UF00075871
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 122941497

Table of Contents
    Historic note
        Historic note
    Main
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida










University of Florida

CENTRAL FLORIDA RESEARCH AND EDUCATION CENTER

Sanford, Florida
Reserach Report SAN 85-15 June 1985


CARROT FERTILIZATION TRIALS AT ZELLWOOD, FLORIDA, 1976-79

R. B. Forbes


Experiments were carried out at Zellwood during the winter
vegetable seasons of 1975-76, 1977-78 and 1978-79 to help develop an
efficient fertilization program for fresh market carrots grown on the
muck and to determine effect of fertilization treatments on residual
nutrients in the soil.

Materials an methods
1017U
The experimental plots were loca ed on this ) i4el wood farm
on Lauderhill muck, a Lithic Medisapr st. This soil is repre tentative
of the shallow organic soils underlai with i omed~o6ko The a ea had
been in use for about 20 or more year with some build-up of esidual
fertility. The cultivar: Hicolor 9 (C ni, Jsed ech y ar. The
experiment was a 3 X 3 X 2 factorial desITg with tr~ ~a205 3
rates of K20, and 2 rates of MgO in all possible combine N (60
lb/A) from NH NO was applied uniformly as was a micronutrient mixture
(Frit 175 G @ 203 b/A). P 0 was supplied from superphosphate, K20 from
muriate of potash and MgO from Emjeo (MgSO ). The fertilizer treatments
were applied by hand and incorporated into the soil as the beds were
formed prior to planting. Plot size was 3 feet by 20 feet or 0.0014 A,
with 2 rows of carrots on each. Treatments were replicated 5 times in
randomized blocks.

Soil samples were taken before fertilization and again at harvest.
Soil pH, salts and nitrates were determined at CFREC-Sanford. The
prepared, dried samples were then analyzed for extractable (Mehlich I or
double and extractant) nutrients by the IFAS Soil Testing Laboratory at
Gainesville. A 10-foot segment of one row was harvested. The 1976-77
trial was planted December 26, 1976, and harvested May 23, 1977. The
1977-78 trial was planted November 1, 1977, and harvested April 12,
1978.

Results and Discussion

The carrot fertilizer trial for 1975-76 was terminated and lost
when heavy rains in April 1976 washed down the beds and destroyed the
plots so no yield data nor soil samples were obtained.






2

1976-77.- Treatments and yields are given in Table 1. Effects of each
element are separated and given in Table 2. Both P 0 and K 0 additions
gave small but significant yield increases of total marketable carrots.
However, there were no significant yield differences in yield of U. S.
Grade A (sizes between 1/2 and 1 1/2" dia. with minimum length of 5").
This grade represents carrots normally packed in small packages for the
retail market. For P20 the yield increase amounted to 1 ton per acre
from the 120-lb/A treatment and 1.5 tons per acre from the 240 Ib rate.
With K 0, there was only a slight increase from the first increment, but
over 1 ton per acre increase from the 400 lb rate.

Response to MgO was very slight and nonsignificant. However, the
interaction between K 0 and MgO proved significant and the data indicate
that the highest yields of all the K 0 X MgO combinations occurred at
the higher rate of both elements. Tie combination of these two elements
was better than either one alone.

1977-78.- In general, yields in 1977-78 were slightly-less in both U. S.
Grade A and total marketable carrots than those realized the year before
with the same series of treatments. There was little or no response to
added P, K or Mg fertilization with no significant differences among the
treatments. None of the interactions proved significant.

Soil Effects 1976-77.- Pre-fertilization samples (Table 5) indicated
moderately high levels of extractable nutrients. Samples taken at
harvest were lost during drying when ink markings on the plastic bags
faded out completely.

Soil Effects 1977-78.- Soil analyses for pH and extractable nutrients
are given in Table 6 from samples taken at harvest. Table 7 gives a
summary of the effects of each level of each nutrient on pH and
extractable nutrients calculated from data in Table 6.

The treatments had little or no effect on soil pH.

Phosphorus.- Extractable P was increased from 73 to 113 ppm by the first
increment of added P20 The next increment (the 240 lb rate) gave
extractable P in excess of 133 ppm, the upper limit being reported by
the Soil Testing Laboratory. This was considered in the high range at
that time. S nce then the ratings of phosphorus soil test values,have
been revised.








1
Soil Testing Laboratory Memorandum 9-22-82, Kidder and Rhue.









Extractable P values for muck soils are now categorized as follows:

Phosphorus Soil Test Results Organic Soils:

P2 0 equiv. to P equiv, to P Classification

Ib/A lb/A ppm

<40 <18 <36 very low
40-80 18-36 36-72 low
81-160 36-70 72-141 medium
160-320 70-141 141-282 high
>320 >141 >282 very high


The revised rating scale would place our P figures in the medium
range. In view of the small response to P, it seems apparent that at
this soil level, only the lower increment of Pp0 fertilizer, if any,
would be needed. Addition of P 0 tended to lower the K and Mg soil
test values slightly and raise h Ca values by a small amount.

Potassium.- Addition of K20 had little effect on pH or extractable P.
Each increment of K 0 added gave a substantial raise in extractable K,
from 223 ppm (already fairly high) to 500 ppm with the higher rate
resulting in 784 ppm in the soil. At the same time there occurred a
slight reduction in both extractable Ca and Mg. Since K concentration
was fairly high even in the untreated plots, there was little response
to K fertilization.

Magnesium.- Addition of Mg raised slightly the extractable Mg level in
the soil which was already at very high levels. There was no effect on
extractable P, and a slight depression in pH, Ca, and K as Mg was added.

1978-79.- The fertilizer trial for 1978-79 was begun on Nov. 9, 1978. A
complete set of soil samples, one sample from each plot, was taken
before treatments were applied.

As harvest approached, heavy rains caused flooding. High
temperatures followed. Such a large percentage of carrots were lost by
sudden onset of soft rot that yields could not be taken. After the
field dried, soil samples from each plot were again taken to gain
information on residual fertility effects from the treatments.

Table 8 presents the analyses of samples taken before treatments
were applied. The overall average from the 90 samples represented is as
follows:
Soluble
pH salts P K Ca Mg
-----------------------ppm----------------

7.3 1530 180 865 18907 1845

These figures reflect a high level of all the extractable
nutrients. Nitrates were checked on selected samples and these values
were also in the high range.









Table 9 gives the analyses from samples taken the following May,
representing soil conditions at what would have been harvest time.
Table 10 shows the effect of the different treatments on soil test
values as calculated from data in Table 9. None of the treatments
showed any appreciable effect on pH or soluble salts.

Phosph6rus.- The P 0 treatments gave an increase in extractable P, 48
ppm increase for tde-120 lb/A addition and-an increase of 105 ppm for
the 240 lb/A P20 rate. The P 0 additions had little influence on
extractable K or Ca, and gave a slight reduction in extractable Mg.

Potassium.- The K20 additions had little or no apparent effect on any of
the extractable nutrients other than K. The first increment of K 0 (200
Ib/A) raised the extractable K from 446 to 672 ppm, an increase of 226
ppm. The 400 Ib/A treatment raised the extractable K concentration
still further, to 811 ppm, an increase of 365 ppm. Extractable K was
down somewhat from the very high values formed in the November samples
but still in the high range.

Ma.nesium.- The addition of MgO had little influence on extractable K or
Ca. However, the extractable P was reduced slightly by the added MgO,
probably through formation of less soluble magnesium phosphates. Even
so, P still remained in the high range. The 60 lb/A addition of MgO
raised the level of extractable Mg by 36 ppm. This is rather small in
comparison to the very high level of Mg in this soil. The high levels
of Mg and Ca are evidently derived from the native limestone and marl
which is present within the soil profile, in this shallow muck area at
depths of 24" or sometimes less.

Summary and Conclusions

These trials unfortunately were not as complete as originally
planned, but do give a better idea of the nutrient supplying power and
buildup of residual fertility in these tremendously productive organic
soils.

Moderate responses to P and K applications were found in the
1976-77 trials. In the 1977-78 trials with higher extractable nutrient
levels in the soil at planting, yield differences were not significant,
nor were there any visual differences in carrot growth observed in the
plot area. With the very high levels of nutrients found prior to
planting the 1978-79 trials, it is doubtful that any of the treatments
would have produced yield gains even if harvest had been possible.
There again, no growth differences could be observed during the growth
period.









Table 1. Carrot yields, fertilizer plots, Zellwood, Florida, 1976-77.


Yield1
U. S. Total
P 0 K 0 MgO Grade A marketable

-------------lb/A------------ -------------T/A----------

0 0 0 10.0 11.2
0 200 0 10.3 10.9
0 400 0 8.7 11.5
0 0 60 9.4 10.6
0 200 60 8.3 10.5
0 400 60 10.9. 13.2

120 0 0 10.0 12.6
120 200 0 9.1 10.7
120 400 0 10.0 12.9
120 0 60 9.0 11.6
120 200 60 10.3 12.9
120 400 60 10.0 13.1

240-- 0 0 9.7 12.8
240 200 0 10.0 12.1
240 400 0 9.4 11.9
240 200 60 10.3 13.9
240 400 60 10.2 12.6

LSD 0.05 N.S. 1.61

Summary
Analysis of Variance F values F values

P205 levels N.S. 10.40***
K20 levels N.S. 6.11 **
MgO levels N.S. N.S.
Interactions All N.S. K X Mg 3.72*
others N.S.


1Average of 5 replicates.












Table 2. Carrot yields, fertilizer trial, 1976-77: effect of each

element. Average yield for each nutrient level.


U. S.
Grade A


Total marketable
carrots


9.60
9.76
10.08


9.58
9.73
10.11


9.84
9.77


11.33
12.33
12.84


11.80
11.85
12.84


12.07
12.25]


Average yield of all replicates of

combinations with other elements.


given nutrient level including all


Nutrient

--lb/A--

205
0
120
240

K20
0
200
400

MgO








Table 3. Carrot yields, fertilizer trials, Zellwood, Florida, 1977-78.


YieldI
Fertilizer Treatments U. S. Total
P205 Kg0 1MgO Grade A marketable

-------------- lb/A-------------- -------------T/A-----------

0 0 0 9.03 10.80
0 200 0 7.64 9.99
0 400 0 7.49 9.29
0 0 60 7.32 9.99
0 200 60 8.10 10.60
0 400 60 8.16 9.38

120 0 0 8.57 10.98
120 200 0 8.02 9.64
120 400 0 9.21 10.43
120 0 60 8.31 9.76
120 200 60 9.03 10.57
120 400 60 6.94 8.80

240 0 0 7.61 10.08
240 200 0 8.13 9.90
240 400 0 8.45 10.28
240 0 60 8.48 10.80
240 200 60 8.80 10.28
240 400 60 7.84 9.23

LSD 0.05 N.S. N.S.

Summary F table
Analysis of Variance F value F value .05 level

P205 levels <1 (N.S.) <1 (N.S.) 3.13
K 20 levels <1 (N.S.) 1.42 (N.S.) 3.13
MgO levels <1 (N.S.) <1 (N.S.) 3.98
Interactions All (N.S.) All (N.S.) --

Average of 5 replicates.










Table 4. Effect of each element. Average yield for each nutrient

level. 1977-78.


U. S. Total
Grade A Marketable

-------------------T/A-----------------


Nutrient

--lb/A--

205
0
120
240

K20
0
200
400

MgO


7.96
8.35
8.22


8.22
8.29
8.02


8.23
8.10


10.00
10.03
10.09


10.40
10.16
9.57


10.15
9.93


Average yield of all replicates of given nutrient level including all

the combinations with other elements.










Carrot fertilizer

Pre-fertilization


trial, Zellwood, Florida, 1976-77.

samples. Soil analysis.


Soluble Extractable nutrients
Sample No. pH No salts Ca Mg P K

----------------- ppm----------------
Pre-fertilization
composite 12-21-76

Rep. A 7.1 med. 255 8000+ 3200 224+ 202

B 7.0 255 2992 224+ 245

C 7.0 237 2832 184 258

D 7.1 218 2640 168 181

E 7.4 218 2416 140 226

X 7.1 med. 237 8000+ 2816 188 222


1Double acid extracting solution:


0.125 M H2SO4 in 0.05 M HC1.


Table 5.








Table 6. 1977-78 carrot fertilizer trial, soil analyses at harvest

Treatment Extractable Nutrients'
P205 K20 MgO pH Ca Mg P K

---------lb/A--------- ----------------ppm--------------

0 0 0 6.3 9568 1186 74 253
0 200 0 6.3 9616 1150 77 516
0 400 0 6.2 9392 1115 69 830
0 0 60 6.0 9680 1256 72 218
0 200 60 6.1 9408 1262 72 538
0 400 60 6.2 9472 1221 74 787

120 0 0 6.4 9760 1154 116 232
120 200 0 6.2 9696 1141 116 486
120 400 0 6.1 9504 1109 111 795
120 0 60 6.0 9536 1227 102 230
120 200 60 6.2 9568 1224 116 534
120 400 60 6.2 9488 1224 116 760

240 0 0 6.0 9968 1118 133+2 224
240 200 0 6.2 9888.. 1125 133+ 493
240 400 0 6.2 9632 1102 133+ 925
240 0 60 6.2 9728 1224 133+ 182
240 200 60 6.0 9792 1195 133+ 432
240 400 60 6.0 9792 1154 131 608

Average of 5 replicates; double acid extracting solution: 0.0125 M
H2SO4 in 0.05 M HC1.

2Above upper limit reported by Soil Testing Laboratory at that time.









Effect of treatments on

fertilizer trial.


soil test values 1977-78, carrot


Bxtractable Nutrients2
Treatment lb/A pH P K Ca Mg

---------------ppm-------------

P205 0 6.18 73 235 9523 1150

120 6.18 113 231 9592 1135

240 6.10 1334 203 9803 1115

K20 0 6.15 73 223 9707 1153

S200 6.20 74 500 9661 1140

400 6.20 72 784 9547 1109

MgO 0 6.21 73 236 9669 1133

60 6.10 73 210 9607 1221


level including


2Double acid extracting solution: 0.0125 M H2SO4 in 0.05 M HC1.


Table 7.


iAverage value from all replicate of- a given nutrient
combinations with other elements.








Table 8. Carrot fertilizer trials, Zellwood, Florida, 1977-78. Soil

analyses before treatment, November 9, 1978.

-Treatment Soluble Extractable nutrients2
P20 K O MgO pH salts P K Ca Mg

-------lb/A ------- -------------------ppm------------------

0 0 0 7.1 1392 189 832 18720 1888
0 200 0 7.1 1420 208 902 18560 1824

0 400 0 7.4 1565 149 739 19200 1920
0 0 60 7.3 1474 176 822 19040 1792

0 200 60 7.4 1684 154 810 19040 1856
0 400 60 7.3 1610 179 938 18880 1760

120 0 0 7.2 1510 193 858 18560 1792
120 200 0 7.3 1465 182 810 18880 1888
120 400 0 7.3 1529 169 854 19040 1920
120 0 60 7.4 1693 164 851 19040 1920
120 200 60 7.3 1456 177 883 19040 1824
120 400 60 7.2 1583 177 822 18880 1824

240 0 0 7.3 2501 167 867 19040 1856
240 200 0 7.1 1474 210 992 18880 1760
240 400 0 7.1 1629 183 944 18880 1856
240 0 60 7.2 1429 204 922 18880 1824
240 200 60 7.2 1674 185 931 19040 1792
240 400 60 7.4 1456 170 794 18720 1920

Avg. 7.3 1530 180 865 18907 1845


Average of 5 replicates.

2Double acid extracting solution.








Table 9. Carrot fertilizer trial, Zellwood, Florida, 1978-79. Soil


analyses


at harvest time, May 21, 1979.


2
Treatment Soluble Extractable Nutrients
P 0 K20 MgO pH salts P K Ca Mg

-------lb/A----- -------------------ppm---------------

0 0 0 7.5 309 154 493 18400 1888
0 200 0 7.5 338 173 752 18240 1792
0 400 0 7.7 333 126 771 18400 1856
0 0 60 7.6 250 150 403 18560 1824
0 200 60 7.7 320 131 563 18560 1920
0 400 60 7.6 317 146 827 18560 1824

120 0 0 7.5 309 208 432 18400 1856
120 200 0 7.6 295 197 563 18400 1888

120 400 0 7.6 350 211 954 18400 1760
120 0 60 7.6 348 179 461 18560 1920
120 200 60 7.5 302 194 672 18400 1792
120 400 60 7.6 275 179 797 18560 1792

240 0 0 7.6 300 271 413 18720 1792
240 200 0 7.4 286 270 803 18560 1728
240 400 0 7.5 300 233 794 18560 1824
240 0 60 7.5 293 256 477 18560 1856
240 200 60 7.5 304 255 678 18240 1856
240 400 60 7.7 311 228 723 18560 1920

Average 7.6 308 198 643 18480 1838


Average of 5 replicates

2Double acid extracting solution.









Table 10.


Effect of treatments on soil test values 1978-79. Carrot


fertilizer trial.


Soluble Extractable Nutrients2
Treatment lb/A pH salts P K Ca Mg

------------------ppm------------------

P205 0 7.6 311 147 448 18453 1845
120 7.6 313 195 446 18453 1835
2 240 7.5 299 252 445 18533 1781

K 0 0 7.6 302 152 446 18533 1845
n 200 7.5 308 152 672 18400 1803
1 400 7.6 314 136 811 18507 1813

MgO 0 7.5 313 151 446 18453 1820
n 60 7.6 302 142 447 18507 1856


1Average value from all replicates of a
combinations with other elements.

Double acid extracting solutions.


given nutrient level including




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs