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Fertilization

Why Fertilize?• Replenish plant nutrients to sustain optimum

growth and health of the plant.

• Losses of nutrients occur through leaching,

clipping removal, irrigation,rainfall, and volatilization

• Essential nutrients for plant growth: C, H, O, P, K, N, S, Ca, Fe, Mg, B, Cl, Cu, Mn, Mo, and Zn.

• Turfgrass requires nitrogen more than any other nutrient

Way to Remember the Elements…

~Mnemonic Devices~

Macronutrients: C, H, O, P, K, N, S, Ca,

Fe, Mg

C HOPK'NS CaFé Management

Micronutrients: B, Mo, Cu, Cl, Mn, Zn

B Mo Cu Cl Mn Zn

Bob’s Mom and Cousin Clio will manage soon

Turfgrasses require 16 Turfgrasses require 16

(some now say 17) (some now say 17) essential elements to essential elements to

grow and complete grow and complete

their life cycletheir life cycle

C, H, O from air and C, H, O from air and waterwater

Remaining 13Remaining 13--14 from 14 from

growing mediagrowing media

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•Most standard turf fertilizers contain N-P-K

and often minors such as Fe, Mg, Ca, etc.

Before fertilizing you should have knowledge

of:• species requirement

• air temperature

• soil moisture• precipitation in forecast?

• type of fertilizer being applied

Importance of Nutrients to TurfgrassGrowth and Development

N P KRooting XShoot growth (tillers.

rhizomes, stolons)X

Leaf growth XColor XEstablishment

(germination andseedlings)

X

Hardinessdroughtheatcold

XXX

Disease susceptibility XWear tolerance X XRecuperative potential XComposition of turf

communityX X

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USGA Greens

Record

Sept./Oct 2003

Jim Skorulski

a) burn potentialb) release rates -water soluble or water insoluble

c) analysisd) safety of product i.e. NH4 NO3

e) cost of product

f) environmental concerns ( i.e. leaching) g) ease of handlingh) spreadability

Important characteristics or facts you need to know when purchasing fertilizer:

Many different types of Fertilizer- discussed here are the more common types of fertilizers used in golf

course management!

HIGHER SALT INDEXHIGHER SALT INDEX

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There are three types we will discuss:

I) synthetic inorganic II) synthetic organic

IIb) Coated synthetic organics

III) natural organic

Nitrogen Fertilizers:

• Nitrogen taken up in two forms: NH4+ or NO3

-

• NO3- mostly

•Nitrification of ammonia to nitrites to nitratesNH4

+ NO2 NO3-

nitrosomas nitrobacter

I) Synthetic inorganic (don't contain C) - In

general characteristics of these fertilizers are:

a) readily soluble in water

b) available to plant almost immediatelyc) can cause growth flushes

d) leach and or volatilize

e) high burn potentialf) are usually cheaper than coated or

controlled release types

1) Ammonium Nitrate NH4N03

- 33%N

- handle with care-very explosive - high salt index

2) Ammonium sulfate NH4SO4

- 21% N- high salt index - used if careful

- may be used to help lower pH3) Potassium Nitrate KNO3

-13% K

- 37%N -Product K power -good to use in fall for hardening off

Examples of synthetic inorganics are:

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i) Urea- is the primary water soluble form. a) rapid response

b) high burn potentialc) high N 46%d) leaches easily

ii) Water insoluble forms include:a) Urea formaldehydeb) IBDU

II) Synthetic organics- group contains both:

i) water soluble and ii) water insoluble forms

a) Urea formaldehyde

-38% N-very slow release rate - (long chain methlylene

urea)-low burn potential-microbes to break it down

-Allows high application rates-long lasting-reduces risk of leaching

Cons:-cost-3-4 weeks before color change (no initial

response)

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-made by reacting urea with isobutyraldehyde

-31% N-slow release rate

-2-4 weeks delay in response

-very expensive-microbes have minimal effect on release rate

-soil moisture particle size, and temperature

influence release rate-be careful if excessive rainfall ie. July

b) IBDU

IIb) Coated synthetic organic fertilizers- provide good initial response compared to IBDU and UF

•Two types - sulfur coated and polymer coated.

Advantages coated materials:a) low burn potential

b) no surge-release rates gradualc) ease of handlingd) Minimal loss to leaching

e) Long or timed duration of feedingg) Reduced labor due to reducing frequency of applications

Consa) costb) mowers or traffic can break coating

1) Sulfur Coated Urea (SCU)-coating = wax prill

-release rates dependent on:•soil temperature and water•coating thickness and size of prill

-20-30% released in first 2 weeks

2) Polymer Coated Urea (http://harrells.com/focus/polyon/)

-urea coated in polymers (plastic)-nutrients release by diffusion and need soil moisture

-soil temperature effects release rates-warmer the temperatures the faster the release-be careful in summer

-Poly-on or osmocote are examples!

Two types:

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SCU / PCUSCU / PCU -- formed by coating ureas formed by coating ureas

granules with sulfur and a thin coating of granules with sulfur and a thin coating of sealant or polymers (wax, resins)sealant or polymers (wax, resins)

III) Natural Organics-Derived from animal or planta) animal manure

b) bone mealc) sewage sludged) dried blood

e) plant refusef) seaweed extract

Characteristics of organicsa) slowly available N

b) Usually a low N content i.e. 6% or lessc) very safe non burningd) warm temperatures and microbes to break

downe) cost > than synthetics

Note*- N in organics present in amine group (-NH2) it must be converted to NH4 before being taken up

by plant called Ammonification:

Also Nitrification=NH4------NO2-------NO3

Many common granular organic products used on golf courses two are:

1) Milorganite 6-2-0 Activated sewage sludge

2) Sustane 5-2-4 composted turkey litter

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Claims of manufacturers and researchers:

-organics not only increase nutrient levels

they have also been shown to reduce:

• disease activity of turfgrasses

• thatch build up or increase decomposition

• nitrate leaching(as with all slow release materials)

• soil compaction (this based on adding

organic matter to soil) however not evident in

studies of three years.

Claims by manufacturers and some researchers regarding organics:

a) reduced soil compaction b) reduced thatch build up or increase decomposition

c) reduced nitrate leachingd) reduce disease activity of turfgrasses

Compost derived fertilizersCompost derived fertilizers

Compost Urea

Snow Mold Nitrogen or organic response?

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Release over many Release over many

weeksweeks

Phosphorous Fertilization----Deficiencies in phosphorous are not as dramatic as NDeficiencies in phosphorous are not as dramatic as NDeficiencies in phosphorous are not as dramatic as NDeficiencies in phosphorous are not as dramatic as N----P deficient turf prone to disease, weed infestations and P deficient turf prone to disease, weed infestations and P deficient turf prone to disease, weed infestations and P deficient turf prone to disease, weed infestations and stress related problems.stress related problems.stress related problems.stress related problems.----P P P P –––– establishment, seed and flower development.establishment, seed and flower development.establishment, seed and flower development.establishment, seed and flower development.Phosphorus facts: Phosphorus facts: Phosphorus facts: Phosphorus facts: • P not mobile in soilP not mobile in soilP not mobile in soilP not mobile in soil• P is affected by soil pHP is affected by soil pHP is affected by soil pHP is affected by soil pHTwo common P sources are:Two common P sources are:Two common P sources are:Two common P sources are:1) Superphospate 201) Superphospate 201) Superphospate 201) Superphospate 20----48% P48% P48% P48% P2) Diammoniumum Phosphate 202) Diammoniumum Phosphate 202) Diammoniumum Phosphate 202) Diammoniumum Phosphate 20----50505050----0000Phosphorous:

• Involved in metabolic processes including

P.S.

• Component of many plant proteins

• mobile in plant

• found in greatest quantities in new cell growth

• deficiencies show up in older leaves

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Potassium Fertilization

Potassium facts:

• Needed in the plant second to Nitrogen

• Leaches readily from sandy soils

• Increase wear tolerance

• Increase drought and heat tolerance

• Increase cold tolerance

• Increase disease tolerance

Three sources used in most K fertilizers:Three sources used in most K fertilizers:Three sources used in most K fertilizers:Three sources used in most K fertilizers:KClKClKClKCl----muriate of potash 60% Kmuriate of potash 60% Kmuriate of potash 60% Kmuriate of potash 60% K2222O S.I.= 114O S.I.= 114O S.I.= 114O S.I.= 114KSOKSOKSOKSO4 4 4 4 50% K50% K50% K50% K2222O Salt Index = 46O Salt Index = 46O Salt Index = 46O Salt Index = 46KNOKNOKNOKNO3333---- 44% K44% K44% K44% K2222O Salt Index = 74O Salt Index = 74O Salt Index = 74O Salt Index = 74

• Positive effect on relieving stress

• Foliar spray potassium silicate reduced

injury to wear

• Improved turf growth, drought and heat resistance

• Quality, Color, and Density increased

• Disease suppression

Recent research with Si has shown:Recent research with Si has shown:

Silicon?

Silicon the second most abundant mineral element in soil after oxygen.

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Silicon continued:

Comments:

• More research needs to be done before

recommendations of Si can be made

• Analytical tools utilized to exam soil and tissue nutrient levels for other nutrients are

not readily available for Si.

• If future studies indicate positive

responses, improving plant performance, disease reduction… then Si could be a

useful tool in IPM practices in turf.

FertilizationFertilizationFertilizationFertilizationDetermining the rate and when to apply fertilizers can be Determining the rate and when to apply fertilizers can be Determining the rate and when to apply fertilizers can be Determining the rate and when to apply fertilizers can be dependent on a variety of factors:dependent on a variety of factors:dependent on a variety of factors:dependent on a variety of factors:• Species

• Length of growing season-ie. Me. vs. N.J.

• Level of quality desired.

• Purpose turf used for (wear factors). i.e. tees v.s.

fairways

• Cultural practices- i.e. Irrigation and clipping

collection reduces nutrient reservoir in soil

•Soil texture i.e sand

• Time of year

• Soil tests

• Type and form of fertilizer- Slow release or fast

release. (Slow release can be applied in greater quantities while soluble should be applied in lesser amounts but more frequent)

• Grade and SGN

Determining fertilizer rate continued:

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Determining Rates and Reading the Label

Complete fertilizer contains N-P-K

Items found on the bag:

• Percent N-P-K

• Weight

• Sources of N-P-K

• Other nutrients present

• % water soluble N

• % water insoluble N

• SGN (maybe)

– called the grade or

analysis

% N

% P2O5

% K2O

Grade

Guaranteed Analysis – minimum percentage of nutrients which is displayed on the label

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83% of the

total N in soluble

form Calculations

Mixed Blended

Homogenous fertilizer–

each granule contains all of the nutrients

SCU prill

Urea prillKSOKSOKSOKSO4444

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SGN = Size Guide Number = Basically prill size

SGN determined by - the size below which 50%of the

particles occur multiplied by 10. for example if 50% fall below 1.9mm then SGN = 190

Indicators that can be used to aid in determining fertilizer timing:

-color

-amount of clippings removed

-wear of turf areas

-physiological growth characteristics of turfgrass

*Fertilization should not be for color alone. A knowledge of turfgrass growth is needed to figure

timing.

Fertilization to build up carbohydrate levels and reserves is important in helping the turfgrass plant

survive stresses*

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Fall Applications N - Promote root growth > carbos.

Root growth cool season grass in fall and spring

Fertilizing in September helps:

a) maintain color for P.S. > in carbohydrates

b) turf heal from summer stress.

Dormant Fertilizing (after last mowing):

a) Maintains color continues to produce carbos.

b) Reduces or eliminates need for spring applications

Early Spring applications –No

Growth flush in spring occurs without fertilizing

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• Supplemental K fertilization will aid in hardening off turf before winter and helps “toughen” the plant

in summer.

• Supplemental Fe will provide color while not pushing growth (usually “short lived”)

Fertilizer Applications

Granular Applications

Types of Seeders

Broadcast- rotary type.

Pros•quick and easy

Cons•wind carries seed /

fertilizer •harder to get uniform coverage.

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Drop spreaders

- Pros - good for small areas with borders -applies precise application

- Cons - slow and can lead to skips or over laps

1) Granular materials are available in different sizes or grades:

•Smaller grades are used on low cut turf this reduces mower pickup•After applying water in

•At next mowing mow without buckets if possible

2) Liquid Applications•applied through sprayer using a boom or gun

•usually light frequent applications•most foliar absorbed

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Advantages of foliar feeding:

• Reduces leaching• Reduces total amount of fert. Require

• Quick plant response

• The applicator is in control-reduces surges if weather conditions change ie.

IBDU

• Full range of products applied at once I.e. Pana sea® and Pro Sol®!

• Mix with pesticides

• No irrigation needed• Uniform Coverage

Disadvantage-Short lived need frequent

applications

Spreader Calibration

With granular fertilizers, initial settings on bags.

Set spreader at setting listed-This is the starting This is the starting point. Then:point. Then:

1) Measure and mark out a known area (say 100’) 2) Place a weighed amount of fertilizer in the

spreader3) Start walking and open hopper at start line and close hopper at finish line.

4) Pour material left into bucket and weigh5) Solve Equation

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Initial wt.-remaining wt. __X___

100 x width of throw 1,000sq’

Adjust spreader accordingly up or downExample: measured area = 100’

Width of throw = 8’

Starting weight = 10 lbs.Finish weight = 5lbs.

=

100’

8’800 sq. feet

Example: measured area = 100’Width of throw = 8’

Starting weight = 10lbs.Finish weight = 5lbs

10 - 5 = X

100 x 8 10005 = x

800 1000

800x = 5,000 X = 6.25 lbs. Fert./1000sq.’

Calibration continued:

Some pointers I recommend when calibrating

a) Calibrate on hard surface???? b) The applicator should be the person

walking the measured area

c) Cut rates in half and go in two directions.

d) Check amounts distributed to the size

of areas. i.e. green size 5,000sq’

There are other methods to calibrate ie. kits

are available to attach to spreaders

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W.C.C. PracticesFairways-

•Late spring-with a polycoated nitrogen source 50% polyon 50%urea. A 20-5-20 at rate of 1.25lbs./1000sq’.

•Late Sept.- 50% SCU and 50%urea 20-5-20 at rate of .75lbs/1000sq’•Last Mowing- 50% SCU 50%urea 20-5-20 at rate

of 1.00lbs./1000sq’•Soluble used when spraying

Roughs and surrounds-Granular applications spring and fall

Tees-Granular Fertilizer at the rate of .5-.75 lbs./1000 /

monthMaterials used are either coated or methylene ureasIron as well as seaweed extracts often added to

spray tank

Greens-

Granulars in the spring and fall total 1.5lbs./yr1/8 lb. foliar every 10-14 days throughout growing season

Organics, Fe, added to spray mix