Fertilizer Task Force Dr. Terril Nell UF/IFAS Environmental Horticulture Dept. (352) ,

Current UF Guidelines for Annual TurfgrassFertilization Rates SpeciesLocationAnnual N Rate (lbs. N 1,000 ft -2 ) BahiagrassNorth2-3 Central2-4 South2-4 BermudagrassNorth3-5 Central4-6 South5-7 CentipedegrassNorth1-2 Central2-3 South2-3 St. AugustinegrassNorth2-4 Central2-5 South4-6 ZoysiagrassNorth3-5 Central3-6 South4-6

Statewide Fertilizer Guidelines These were developed with all pertinent turf faculty in 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.

Total Annual N Leached During Establishment of Empire Zoysiagrass in 2005 N (mg M 2 ) a aa Trenholm, 2005

Percent of Applied N Leached from Empire Zoysiagrass in 2005 Percent of Applied N Leached % N aab b Trenholm, 2005

Total Annual N Leached in Established Empire and Floratam in 2005 N (mg M2) Total N Leached aaaa Trenholm, 2005

Percent of Applied N Leached from Established Empire and Floratam in 2005 Percent of Applied N Leached % N aabcbc Trenholm, 2005

Other Turf Nutrient Leaching Research Work done by Dr. Jerry Sartain

Effect of N Source on % N Recovered in Leachate in Established FloraDwarf Bermudagrass

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 Ecology  Turfgrass and Landscape Faculty  Grant Opportunities