1. 4/13/2012
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
(some now say 17)
essential elements to
grow and complete
their life cycle
C, H, O from air and
water
Remaining 13-14 from
13-
growing media
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2. 4/13/2012
•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 Turfgrass
Growth and Development
N P K
Rooting X
Shoot growth (tillers. X
rhizomes, stolons)
Leaf growth X
Color X
Establishment X
(germination and
seedlings)
Hardiness
drought X
heat X
cold X
Disease susceptibility X
Wear tolerance X X
Recuperative potential X
Composition of turf X X
community
2

3. 4/13/2012
USGA Greens
Record
Sept./Oct 2003
Jim Skorulski
Many different types of Fertilizer- discussed here are
the more common types of fertilizers used in golf
course management!
Important characteristics or facts you need to know
when purchasing fertilizer:
a) burn potential
b) release rates -water soluble or water insoluble
c) analysis
d) safety of product i.e. NH4 NO3
e) cost of product
f) environmental concerns ( i.e. leaching)
g) ease of handling
h) spreadability
HIGHER SALT INDEX
3

4. 4/13/2012
Nitrogen Fertilizers:
There are three types we will discuss:
I) synthetic inorganic
II) synthetic organic
IIb) Coated synthetic organics
III) natural organic
• Nitrogen taken up in two forms: NH4+ or NO3-
• NO3- mostly
•Nitrification of ammonia to nitrites to nitrates
NH4+ 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 immediately
c) can cause growth flushes
d) leach and or volatilize
e) high burn potential
f) are usually cheaper than coated or
controlled release types
Examples of synthetic inorganics are:
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 pH
3) Potassium Nitrate KNO3
-13% K
- 37%N
-Product K power
-good to use in fall for hardening off
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5. 4/13/2012
II) Synthetic organics- group contains both:
i) water soluble and ii) water insoluble forms
i) Urea- is the primary water soluble form.
a) rapid response
b) high burn potential
c) high N 46%
d) leaches easily
ii) Water insoluble forms include:
a) Urea formaldehyde
b) IBDU
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)
5

6. 4/13/2012
b) IBDU
-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
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 gradual
c) ease of handling
d) Minimal loss to leaching
e) Long or timed duration of feeding
g) Reduced labor due to reducing frequency of
applications
Cons
a) cost
b) mowers or traffic can break coating
Two types:
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!
6

7. 4/13/2012
SCU / PCU - formed by coating ureas
granules with sulfur and a thin coating of
sealant or polymers (wax, resins)
III) Natural Organics-Derived from animal or plant
a) animal manure
b) bone meal
c) sewage sludge
d) dried blood
e) plant refuse
f) seaweed extract
Characteristics of organics
a) slowly available N
b) Usually a low N content i.e. 6% or less
c) very safe non burning
d) warm temperatures and microbes to break
down
e) 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
7

8. 4/13/2012
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 leaching
d) reduce disease activity of turfgrasses
Compost derived fertilizers
Compost Urea
Snow Mold
Nitrogen or organic response?
8

9. 9
• deficiencies show up in older leaves
growth
• found in greatest quantities in new cell
• mobile in plant
• Component of many plant proteins
P.S.
• Involved in metabolic processes including
Phosphorous:
0-05-02 etahpsohP mumuinommaiD )2
P %84-02 etapsohprepuS )1
:era secruos P nommoc owT
Hp lios yb detceffa si P •
li o s ni eli b o m t o n P
li o s ni eli b o m t o n P
li o s ni eli b o m t o n P •
:stcaf surohpsohP
:stcaf surohpsohP
:stcaf surohpsohP
:stcaf surohpsohP
.tnempoleved rewolf dna dees ,tnemhsilbatse – P-
.tnempoleved rewolf dna dees ,tnemhsilbatse – P-
.tnempoleved rewolf dna dees ,tnemhsilbatse – P-
.tnempoleved rewolf dna dees ,tnemhsilbatse – P-
.smelborp detaler sserts
dna snoitatsefni deew ,esaesid ot enorp frut tneicifed P-
N sa citamard sa ton era suorohpsohp ni seicneicifeD-
Phosphorous Fertilization
weeks
Release over many
4/13/2012

10. 4/13/2012
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
:srez tref K tsom n desu secruos eerhT
:srez tref K tsom n desu secruos eerhT
:sreziiiilllliiiitref K tsom niiii desu secruos eerhT
:srez tref K tsom n desu secruos eerhT
411 =.I.S O2K %06 hsatop fo etairum-lCK
2
6 4 = x e d nI t a S
6 4 = x e d nI t a S
64 = xednI tllllaS
6 4 = x e d nI t a S O K %05
O2K %05
O K %05
O K %05 OSK
4OSK
OSK
OSK
47 = xednI t aS
47 = xednI tllllaS
47 = xednI t aS
47 = xednI t aS O2K %44
O2K %44
O2K %44
O2K %44 -3ONK
-3ONK
-3ONK
-3ONK
Silicon?
Silicon the second most abundant mineral element
in soil after oxygen.
Recent research with Si has shown:
• 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
10

11. 4/13/2012
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.
noitazilitreF
n
eb nac srezilitref ylppa ot nehw dna etar eht gninimreteD
:srotcaf fo yteirav a no tnedneped
:srotcaf fo yteirav a no tnedneped
:srotcaf fo yteirav a no tnedneped
:srotcaf fo yteirav a no tnedneped
• 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
Determining fertilizer rate continued:
•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
11

12. 4/13/2012
Determining Rates and Reading the Label
Complete fertilizer contains N-P-K – called the grade or
analysis
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)
% P2O5
%N
% K2O
Grade
Guaranteed Analysis – minimum percentage of
nutrients which is displayed on the label
12

13. 4/13/2012
83% of
the
total N
in
soluble
form Calculations
Mixed Blended
SCU prill
Urea prill
OSK
OSK
OSK
OSK 4
Homogenous fertilizer–
each granule contains all
of the nutrients
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14. 4/13/2012
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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15. 4/13/2012
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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16. 4/13/2012
• 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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17. 4/13/2012
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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18. 4/13/2012
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
point. Then:
1) Measure and mark out a known area (say 100’)
2) Place a weighed amount of fertilizer in the
spreader
3) Start walking and open hopper at start line and
close hopper at finish line.
4) Pour material left into bucket and weigh
5) Solve Equation
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19. 4/13/2012
Initial wt.-remaining wt. __X___
=
100 x width of throw 1,000sq’
Adjust spreader accordingly up or down
Example: measured area = 100’
Width of throw = 8’
Starting weight = 10 lbs.
Finish weight = 5lbs.
800 sq. feet
8’
100’
Calibration continued:
Example: measured area = 100’
Width of throw = 8’
Starting weight = 10lbs.
Finish weight = 5lbs
10 - 5 = X 5 = x
100 x 8 1000 800 1000
800x = 5,000 X = 6.25 lbs. Fert./1000sq.’
There are other methods to calibrate ie. kits
are available to attach to spreaders
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’
19

20. 4/13/2012
W.C.C. Practices
Fairways-
•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 /
month
Materials used are either coated or methylene ureas
Iron as well as seaweed extracts often added to
spray tank
Greens-
Granulars in the spring and fall total 1.5lbs./yr
1/8 lb. foliar every 10-14 days throughout growing
season
Organics, Fe, added to spray mix
20