| Material Information
||Slow release fertilizer for tomatoes at seeding
||Homestead AREC research report
||2 leaves : ; 28 cm.
||Orth, Paul G
Agricultural Research and Education Center, Homestead
||University of Florida, Agricultural Research and Education Center
||Place of Publication:
||Tomatoes -- Fertilizers -- Florida ( lcsh )
||government publication (state, provincial, terriorial, dependent) ( marcgt )
non-fiction ( marcgt )
||Statement of Responsibility:
||"August 31, 1973"
| Record Information
||University of Florida
||All rights reserved by the source institution and holding location.
||oclc - 72441277
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
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
/ r Homestead AREC Research Report SB73-3 August 31, 1973
Slow Release Fertilizer for Tomatoes at ISeeding
i'tonanp as3 Paul G. Orth' ....y < !ri;v-7 i ....
Leaching of nitrogen and potassium from fertilizer applied to tomatoes can be a seri-
ous problem in fields planted before the end of the rainy season. Slow release ferti-
lizers are designed to resist leaching, a24 only a minor portion is capable of enter-
ing the soil solution each day. Osmocote-.fertilizers plus phosphate (0-46-0) have
been used at planting to get good seedling growth (1). This fertilizer was semi-
banded with the seed at planting.
A semi-band results when a low rate of fertilizer is dropped into a furrow and, due
to scattering by motion of the equipment and bouncing as it hits the soil, it is
deposited over a 1 to 2 inch area. Rates of 15 lbs N and 15 Ibs K20/A from Osmocote
and 15 to 30 Ibs P205 from 0-46-0 were found to produce good seedlings (1).
Since Osmocote is relatively expensive, about $660 per ton of 14-14-14, potentially
less expensive experimental materials were used during the 1972-73 season. These were
sulfur-coated fertilizers prepared by TVA. Preliminary work indicated these materials
were toxic when placed in the seed furrow and, when banded two inches from the seed,
growth was retarded until the roots reached the fertilizer band. Two experiments were
conducted to determine if a reduced rate of Osmocote placed in the seed furrow com-
bined with rates of sulfur-coated fertilizer banded near the seed would provide ade-
quate N and K for seedling growth.
The two experiments are outlined in table 1. Treatments were replicated six times.
Materials used for placement in bands were sulfur-coated urea, sulfur-coated muriate
of potash, and 0-46-0. Materials used for placement with the seed were Osmocote
14-14-14 and 0-46-0. The first experiment was planted September 20, 1972 and the
second February 6, 1973. No effort was made to leach the plots. Seedling growth was
good on all treatments in both experiments. Treatment 1 produced only slightly small-
er plants than the other treatments, and the difference was not statistically signifi-
cant. This is shown in table 2 which contains the average plant weights 28 days after
planting in experiment 1 and 41 days after planting in experiment 2. The growth rate
in experiment 1 averaged 24%/day the week before this sampling and 17% the two weeks
after. In experiment 2 the growth rate averaged 16 to 17% the week before and the
week after the March 19 sampling. None of the treatments reduced seedling growth or
showed visible injury. Additional fertilizer was not applied until at least 4 weeks
after planting; conventional fertilizer was side-dressed at this time.
In summary the following four conclusions are important. (1) None of the fertilizer
rates used are likely to injure tomato seedlings when applied in the manner outlined.
(2) Slow release fertilizer increases the time between planting and the first appli-
cation of conventional fertilizers. (3) The quantity of Osmocote placed with the
seed can be decreased when sulfur-coated fertilizer is banded 2 inches from the seed.
(4) This planting method should be tested in commercial fields.
Since sulfur-coated fertilizer is not available commercially, a few demonstration rows
in cooperators fields are planned for this season and early next season.
Assistant Soils Chemist, Agricultural Research and Education Center, University of
Florida, IFAS, Homestead, Fla. 33030
/ Registered trademark of Sierra Chemical Co., Newark, California.
Table 1. Slow Release Fertilizer Applied at Planting.
Nutrient Rates (lbs/A)-/
Treatment In Band With Seed
number N P205 K20 N P205 120
1 0 60 0 10 20 10
2 30 60 30 10 20 10
3 60 60 60 10 20 10
4 30 60 30 0 20 0
5 30-/ 60 30-/ 10 20 10
Nutrient Rates (Ibs/A)3/
Treatment In Band With Seed
number N P205 K20 N P205 K20
1 0 30 0 5 10 5
2 15 30 15 5 10 5
3 30 30 30 5 10 5
4 15 30 15 0 104/ 0
5 0 30 0 0 30- 0
1All treatments received 20 lbs MgO and 10 Ibs MnO/A;
14,500 ft. of row/A.
2/N and K were broadcast and crudely mixed in the soil
over a 6 inch wide strip in the planting area.
3/All treatments received 10 lbs MgO and 5 Ibs MnO/A;
7,250 ft. of row/A.
4/Rate should have been 10 but an error in hopper set-
ting gave this rate on 4 of 6 plots.
Table 2. Average seedling weight (grams/plant).
Treatment Experiment 1 Experiment 2
number 10/18 3/19
1 0.92 0.98
2 1.07 1.18
3 1.12 1.11
4 1.08 1.09
5 1.12 1.14
1. P. G. Orth. 1972. Growth response by tomato seedlings to slow release fertilizer
placed with the seed. Soil and Crop Sci. Soc. of Fla. Proc. 32 (In Press).