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Fertilizer Task Force. Dr. Terril Nell UF/IFAS Environmental Horticulture Dept. (352) 392-1831, [email protected]. Current UF Guidelines for Annual TurfgrassFertilization Rates. SpeciesLocationAnnual N Rate (lbs. N 1,000 ft -2 ) BahiagrassNorth2-3 Central2-4 - PowerPoint PPT Presentation
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Fertilizer Task Force
Dr. Terril NellUF/IFAS Environmental Horticulture Dept.(352) 392-1831, [email protected]
Current UF Guidelines for Annual TurfgrassFertilization Rates
Species Location Annual N Rate (lbs. N 1,000 ft-2)
Bahiagrass North 2-3Central 2-4South 2-4
Bermudagrass North 3-5Central 4-6South 5-7
Centipedegrass North 1-2Central 2-3South 2-3
St. Augustinegrass North 2-4Central 2-5South 4-6
Zoysiagrass North 3-5Central 3-6South 4-6
Statewide Fertilizer Guidelines These were developed with all pertinent turf faculty in
2000-2001 at request of Dean Dusky Developed as interim recommendations until research
indicates a need for change The collective faculty felt that these rates would provide
for strong healthy turf without negative environmental impacts
Allow for homeowner (do-it-yourselfers) and professional applications
Do not cover nutritional requirements of athletic fields or golf courses
Statewide Fertilizer Guidelines These guidelines only recommend N application
rates Other nutrient requirements (primarily P) should
be based on soil or tissue tests Potassium generally applied at a ratio of 2:1 N:K
or 1:1 N:K Based on professional preferences/experiences or what
analysis fertilizer consumer happens to buy Other macronutrients seldom limiting in turf in FL In high pH soils, recommend application of soluble
Fe and Mn
Data for DACS Fertilizer Rule Nitrogen data based on best available
information and consensus of all parties involved
Phosphorus data based on calculations done by Dr. Sartain relating to St. Augustinegrass P nutritional requirements
Sustainability
Nutritional maintenance program designed to sustain turf health and growth under both optimal and stress (disease, pest, drought, traffic, salinity, etc.) conditions, where inputs will not cause environmental impacts
Run Off Issues
Research has shown that during grow-in, less than 0.03% of applied N was collected as run-off on a 10% slope in bermudagrass
Shaddox and Sartain, 2005, Proc Fl Soil and Crop
Buffer Zone Around Water Bodies No research base currently for establishment of
buffer zone Many propose large untreated areas, but these
may actually contribute to increased NPSP Larger buffer zones may contribute to NPSP due
to loss of turf stand, increased stormwater runoff, and soil erosion
Area of needed research
Model Ordinance
FDEP publication (2002) with input from UF, WMDs, environmental organizations, FFAA, pest control industries, and other stakeholders
Designed to be a template for local governments to use when considering landscape ordinances
BMP Educational Program Development FDEP program that is delivered by IFAS Designed to train landscape and pest control industries how to
do their jobs without causing pollution Program began in 2002 Dr. Trenholm is grant PI and lead trainer is this program-
offered at IFAS County Extension offices statewide Approximately 2,300 people trained in statewide training
sessions to date Others (~100) have been trained on-line at greenindustries.org FDEP has invested approximately $700,000 in this program to
date
BMP Educational Program Development Program now offered in both English and
Spanish (at certain locations only at this time) Currently development of the “Train the Trainer”
program is underway This program is a requirement in most
city/county ordinances DACS is currently planning to include some or
all of this program in the L&O licensing exam
BMP Development and Fertilizer Issues Annual fertilizer rate guidelines used in BMP
educational program Rates for each application limited to:
0.5 lbs. N per 1,000 ft-2 for quick-release sources* 1.0 lbs. N per 1,000 ft-2 for slow-release sources
Nitrogen sources discussed in BMPs, but no recommendation of one over another – when properly applied, turf has excellent ability to take up all N sources
* Differs from DACS Fertilizer Rule
Nutrient Leaching Research
Current FDEP funded project: 5-6 year 3 locations statewide Quantifying nutrient leaching in lawn grasses under a wide
variety of circumstances Nitrogen rates Nitrogen sources (to start 08 or 09) Winter fertility Establishment fertility Soil type Phosphorus requirement and leachability
Nutrient Leaching Research
Preliminary data collected do not meet FDEP quality assurance requirements because of prolonged storage prior to analysis
FDEP and IFAS are working towards recovering most of the data by developing correction curves
Lysimeters buried in center of each plot
As nitrate percolates downward through the column, it collects in reservoir filled with gravel. At bottom of lysimeter is a portal for tubing that runs to collection device aboveground. To collect leachate, a vacuum pump is attached the the tubing and water evacuated from base. A sub-sample is collected for analysis.
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
Total N Leached
0.5 lbs N
1.0 lbs N
2.0 lbs N
Total Annual N Leached During
Establishment of Empire Zoysiagrass in 2005N
(m
g M
2 )
a
a a
Trenholm, 2005
Percent of Applied N Leached from
Empire Zoysiagrass in 2005
0
20
40
60
80
100
120
140
0.5 lbs. N
1.0 lbs. N
2.0 lbs. N
Percent of Applied N Leached
% N
a ab
b
Trenholm, 2005
Total Annual N Leached in Established Empire and Floratam in 2005
0
100
200
300
400
500
600
700
800
900
1000
0.6 lbs N
1.3 lbs N
2.6 lbs N
4 lbs N
N (
mg
M2)
Total N Leached
a a a a
Trenholm, 2005
Percent of Applied N Leached from Established
Empire and Floratam in 2005
0
2
4
6
8
10
12
14
16
18
0.6 lbs N
1.3 lbs N
2.6 lbs N
4.0 lbs N
Percent of Applied N Leached
% N
a ab cbc
Trenholm, 2005
Other Turf Nutrient Leaching Research
Work done by Dr. Jerry Sartain
LEACHING N LOSS FROM SLOW-RELEASE N SOURCES
80
62 5850
2817
AS CAS NUT SCU NIT IBDU
NITROGEN SOURCES
0
20
40
60
80
100
% N
LE
AC
HE
D
PERCENTAGE OF APPLIED N LEACHEDFROM RYEGRASS(2 LBS N/1000 SQ FT/125 d)
12.8
8.17.2
2.9 2.8 2.81.1 0.4
ASUAN
CORONNUTRALENE
POLYONSCU
IBDUNITROFORM
NITROGEN SOURCE
0
2
4
6
8
10
12
14
PE
RC
EN
TAG
E O
F A
PP
LIE
D N
LE
AC
HE
D (
%)
A B B C C C D E
EFFECT ON N SOURCE ON % N RECOVEREDDURING FLORADWARF MAINTENANCE PHASE
52.7
0.54.3
57.8
47.3
0.1
7
54.456
2.6 4.7
63.2
UPTAKE LEACHED SOIL % RECOVERED
RECOVERED PARTITION
0
10
20
30
40
50
60
70
PE
RC
EN
TAG
E O
F A
PP
LIE
D (
%)
AN AN + MIL AN + MIL + IBDU
Effect of N Source on % N Recovered in Leachate
in Established FloraDwarf Bermudagrass
CUMMULATIVE TOTAL N LEACHED AS UREA, NH4 AND NO3
1409
1076
521
284
1513
858
CAS NUT NIT IBDU AS SCU
NITROGEN SOURCE
0
200
400
600
800
1000
1200
1400
1600
1800
TO
TAL
N L
EA
CH
ED
(m
g)
UREA
NH4
NO3
Environmental Impact
Research Needed Buffer zone fertilization for minimizing environmental
impacts (slope, soil type) Nutrient uptake and losses from blended vs.
homogenous fertilizers Long-term effects of nutrient deprivation during rainy
seasons on turfgrass growth and health Comparative N and P losses of turf relative to
ornamentals and shrubs Relationship of landscape and turf fertilization and
red tide
Integrated Approach
Center for Landscape Conservation and EcologyTurfgrass and Landscape FacultyGrant Opportunities