Florida-Friendly

Best Management Practices for Protection of Water Resources by the Green Industries

Fertilizer Module 4

Draft FINAL Version August 24, 2009

At the end of this module you will be able to:

• Identify the different types of common fertilizers

• Interpret and apply the information on a fertilizer label

•Implement practices to avoid runoff and leaching of fertilizers

• Calculate the amount of fertilizer to be applied according to the recommended rates

• Apply recommended rates

Training Objectives

What are fertilizers?

Nutrients

Macronutrients:

• Nitrogen

• Phosphorus

• Potassium

• Calcium

• Magnesium

• Sulfur

From Environment:

• Carbon

• Hydrogen

• Oxygen

Micronutrients:

• Iron

• Manganese

• Boron

• Copper

• Molybdenum

• Zinc

• Nickel

Soil Test• Basis for determining a fertility program

• pH as well as macro and micro nutrients

• Phosphorus testing is particularly important

• Do not soil test for No Very mobile

o Use IFAS recommended rates

Soil pHNutrient

Availability

Strongly acidic

Medium acidic

Slightly acidic Very slightly acidic

Very slightly alkaline

Slightly alkaline

Medium alkaline

Strongly alkaline

Nitrogen Fertilizers

Quick Releasealso “water soluble” or “readily available”

Ammonium Sulfate

• 21% N (NH4)2SO4

• Deep green, longer response than many other soluble N

• Highly soluble and leachable

• Volatilization

• Very acidifying – useful in high pH soils

• High salt index - 3.25 – must be watered in

Urea• 46% N

• Soluble synthetic organic

• Nonionic, highly leachable

• Subject to volatilization

• Low acidity - 1.8/kg N

• Low salt index - 1.62

Ammonium Nitrate• 33 – 34 % N

• Very soluble

• Subject to volatilization and leaching

• Low acidity - 1.8/kg N

• High salt index - 2.99

• Can be explosive

• Short term response

Nitrogen Fertilizers

Slow Releasealso “controlled release” (CR) or

water insoluble (WIN)

Urea Formaldehyde• Insoluble organic

• 38% N; 65-71% WIN

• Biological N release

o Rate influenced by soil temperature

o Less effective in cool seasons

• Microbes release N as urea

Methylene Urea• 40% N - 36% WIN

• Biological N release

• More rapidly available than UF

• Not as adversely influenced by cool temperatures

Isobutylidene Diurea - IBDU• 31% N

• 90% slow release

• N released by hydrolysis as urea

• Relatively unaffected by

o Temperature

o pH

• Particle size important

• Excellent cool season response

• Less effective during heavy rain periods due to rapid release

Sulfur Coated Urea • 32-38% N• Release depends upon:

o Thickness of sulfur coatingo Biologicalo Soil environment

Temperature pH

• Cool season response-erratic

• Drop spreaders may crack pellets

• Response up to 4 months

Polymer Coated

• Variable N

• May contain other sources, other nutrients

• N release influenced byo Coating thicknesso Diffusion rateo Soil temperature

• Good for both warm and cool season

• Longer residual in warm temps

Leaching & Runoff PotentialQuick release sources vs. slow release sources

• Quick release sources, properly applied, do not leach significantly more

• The potential for leaching due to misapplication or overwatering is greater with soluble sources

• The potential for leaching due to heavy rain soon after applying is greater with soluble sources

• The potential for runoff due to heavy rain several weeks after application may be greater with slow release sources

Why use slow release fertilizers?

Fertilization of Established Grasses:• Should be applied based on soil and/or tissue test

• Often ample in plant available form in FL

• Turf needs are low

• DACS Fertilizer Rule limits use:o 0.25 lb 1,000 ft-2 per applicationo 0.5 lb 1,000 ft-2 yearly

• Needs increase under traffic or other stresses

Phosphate Fertilizers

Potassium

• Potassium is like a multi-vitamin for turf

• Provides some resistance to many stresses

• Is not a curative, but should be part of a fertilization plan

• N:K ratio 2:1 or 1:1 under stress

• A Magnesium deficiency may be found in many parts of the State

• 2 ½ lbs. Mg/1000ft²/yr may be applied

Magnesium (Mg)

What about micro nutrients?

Fertilizer LabelBRAND NAMEGRADE X-X-X

Guaranteed AnalysisTotal Nitrogen (N) _____%_____% Nitrate Nitrogen _____% Ammoniacal Nitrogen _____% Water Soluble Nitrogen _____% Urea Nitrogen _____% Water Insoluble Nitrogen Available Phosphate (P205) _____%Soluble Potash (K20) _____%Chlorine, (Cl) Not More Than . _____%_____% Total Magnesium as(Mg ) _____% Water Soluble Magnesium as (Mg) _____% Chelated Magnesium (Mg) _____% Total Manganese as (Mn) _____% Water Soluble Manganese as (Mn) _____% Chelated Manganese as (Mn) _____% Total Copper as (Cu ) _____% Water Soluble Copper as (Cu) _____% Chelated Copper as (Cu) _____% Total Iron as (Fe ) _____% Water Soluble Iron as (Fe) _____% Chelated Iron as (Fe) _____% Total Zinc as (Zn) _____% Water Soluble Zinc as (Zn) _____% Chelated Zinc as (Zn) _____% Combined Sulfur as (S) _____% Free Sulfur as (S)

Derived from: (Actual materials and in forms used in the fertilizer mixture, e.g., Diammonium Phosphate, Urea, Potassium Chloride, Magnesium Sulfate, Manganese Nitrate, etc.)

Manufactured by:Name (FXXXX)

City, State & ZipNet Weight - _______ lb

Do you need a license to apply fertilizers?

Limited Commercial Fertilizer Applicator Certificate (LCFAC)

• Issued by FDACS - Chapter 482

• Required by January 1, 2014

• GI-BMP training certificate pre-requisite [approved equivalent]

• $25 fee, renewal every 4 years

• 4 hours of CEUs required for renewal

• Not required if application is only to property owed by you, your firm, or your employer

• LCFAC holders are exempt from further local testing

Fertilizer Calculations

Single N Applications

• Depends on percentage slow-release N:

o 0.5 lb. N 1000 ft2 if water soluble

o Up to 1 lb. N 1000 ft2 if slow-release

• Follow UF recommended annual N rates

N Calculations

15-0-15, 50% slow-release N

How much N per 1,000 ft2?

N Calculations

How much 15-0-15 will supply the correct N amount to 1,000 ft2?

100/15 = 6.6

6.6 lbs. to cover 1,000 ft2 at 1 lb N /1,000 ft2

N Calculations

Fertilizer Calculations- Milorganite

How much 6-2-0 fertilizer?

Formula> 1 lb /1,000 ft2

Remember that this product has 2% phosphorus, only 12.5 lb. may be applied if there is not a P deficiency

100/6 = 16.616.6 lbs. to cover 1,000 ft2 at 1 lb N /1,000 ft2

Fertilizer Calculations- Milorganite

Fertilizer Calculations- Urea

How much 46-0-0 (quick release) fertilizer?

Fertilizer Calculations- Urea

Formula> 0.5 lb /1,000 ft2

100/46 = 2.2To apply 0.5 lb. N per 1,000 ft2:

2.2 /2 = 1.11.1 lbs. to cover 1,000 ft2 at 1 lb N /1,000 ft2

6% N (Low) Larger amounts of fertilizer

15% N (Medium) Medium amounts of fertilizer

46% N (High) Very Low amounts of fertilizer

FertilizerCalibration, Application, Storage

• Calibrate spreaders & sprayers frequently

• Ensure they are clean and maintained properly

• Double check the material used and application rate desired

Calibration

Spreader Calibration• Determine amount needed for the

test area

• Capture material (bucket or measured tarp)

• Walk the spreader over test area

• Weigh applied material

• Compare to the required amount

• Adjust spreader

Sprayer Calibration• Determine how much fertilizer is

needed for the test area

• Determine how long it takes to spray that area

• Determine the amount sprayed in that time

• Compare and adjust as needed

• Deliver the fertilizer to the target

• Check the delivery rate

• Check for appearance

• Avoid non-target surfaces

• Operate the equipment safely

Application

ApplicationMeasure the lawn area

40’25’

40’ x 25’ = 1,000 square feet of front lawn

Take half of the total amount of fertilizer:o 15% = 6.6 lbs fertilizer per 1,000 square feeto Half of this = 3.3 lbs fertilizer in spreader

Then take the remaining fertilizer and go in other directions

Application

Then take the remaining fertilizer and go in opposite directions

This will help you apply the correct amount of fertilizer!

Application

Buffer?

• Use a deflector shield near water

• Leave at least 3’ ring

• Without a shield leave 10’ ring

• Ordinances may vary

• Use the shield near impervious areas and storm water systems

Application

¼ InchOnly enough water to move granules off of leaves

Application

Sweep-up spills!Fertilizer on impervious (paved) surfaces can pollute water bodies

Fertilizer Storage• Store fertilizer in areas protected

from rainfall

• Load fertilizer away from wells or waterbodies

• Store fertilizer away from flammable substances

• Clean up spills immediately

Irrigation After Fertilization

• Even at proper rates, too much water can result in leaching or runoff

• Irrigate fertilizer in with ¼” of water

• Do not fertilize when heavy rainfall is expected

(NWS tropical watch or warning or flood watch for the area)

• Proper application is more important than the type of fertilizer

• Soluble N sources differ in chemical properties and handling requirements

• Slow-release N sources are not 100% slow-release and they differ in their release properties

Review

• Knowledge of fertilizer management is one of the most important tools in limiting the environmental impact

• Irrigation Management is the other critical tool

• Educating the customer is critical

• New Limited Commercial Fertilizer Applicator Certificate (LCFAC) by 2014

Review (continued)

This slide set was adapted from the presentation SOLUBLE vs. CONTROLLED RELEASE NITROGEN FERTILIZERS by J.B. Sartain

University of Florida

byMike Thomas, FDEP

Laurie Trenholm, UF-IFASAlberto Chavez, FDEP

Last update August 24, 2009

Thank you!