5/9/2012
The Nuts and Bolts of a Foliar Fertility Program
Mike Richardson
Professor
University of Arkansas
Why study foliar fertilization?
% of total N as foliar on greens
50
42
40
30
25
25
20
8
10
0
0
No foliar
< 25%
25-50%
50-75%
>75%
Outline of today’s seminar…
• Background info about foliar fertilizers
• Physiology of nutrient uptake through leaves
• Foliar nutrient uptake studies
• Cost analysis of foliar nitrogen products
1
5/9/2012
Liquid
Water-soluble complete
Are these foliar fertilizers ?
Water-soluble nitrogen
Why would you use foliar fertilization?
Benefits of Foliar Fertilization on Putting Green Management
• Ease and accuracy of application
• Provide more consistent growth
• Provide nutrients during periods when root physiology is compromised
• Provide secondary benefits, when incorporated with biostimulants
• Improved uptake efficiency
• Environmental safety
2
5/9/2012
Frequent spoon‐feeding will produce more consistent growth than infrequent applications of fertilizer
Growth rate of perennial ryegrass as affected by frequency of soluble N applications
Monthly
Growth rate / day
90
80
70
60
50
40
30
20
10
0
30
40
50
60
70
80
Days
90
100
110
120
130
Bowman, 2003
Growth rate of perennial ryegrass as affected by frequency of soluble N applications
Monthly
2 weeks
70
90
Growth rate / day
90
80
70
60
50
40
30
20
10
0
30
40
50
60
80
Days
100
110
120
130
Bowman, 2003
3
5/9/2012
Growth rate of perennial ryegrass as affected by frequency of soluble N applications
Monthly
2 weeks
1 Week
Growth rate / day
90
80
70
60
50
40
30
20
10
0
30
40
50
60
70
80
Days
90
100
110
120
130
Bowman, 2003
Growth rate of perennial ryegrass as affected by frequency of soluble N applications
Monthly
2 weeks
1 Week
Daily
Growth rate / day
90
80
70
60
50
40
30
20
10
0
30
40
50
60
70
80
Days
90
100
110
120
130
Bowman, 2003
Some opening thoughts about nutrient uptake…
• Grasses were not designed to
absorb nutrients through the
leaves
• Capacity for absorption is much
greater in roots compared to
leaves
• Some nutrients can only be
moved to areas of need via root
uptake
4
5/9/2012
What are the barriers to nutrient absorption through the leaves ?
• Assumed that the primary ports of nutrient entry are:
– Stomates
– Cuticular wax
Stomatal effects on nitrogen uptake
Nitrogen uptake at 8 h (% of applied)
Night
Day
100
90
80
70
60
NS
NS
50
40
30
20
10
0
Sep‐09
Oct‐09
cuticular ledge
Stomatal pore
GC
GC
GC
GC
internal cuticle
internal cuticle
Bentgrass
Bermudagrass
5
5/9/2012
How does foliar fertilization affect nutrient movement in the turf?
Nutrients that can be absorbed through the leaves
Macronutrients
Micronutrients*
• Nitrogen + + +
• Phosphorous +
• Potassium + + +
• Zinc
• Iron • Boron
• Sulfur
* Often applied as chelates
What about other nutrients?
• Calcium
• Silicon
• Manganese
All can be absorbed
by leaves
• Magnesium
6
5/9/2012
Once absorbed, how are nutrients moved in the plant?
• Xylem
–up
• Phloem
–up or down
Botany Basics
Xylem – non‐living cells

Transport water and nutrients by mass flow
Phloem – living cells

Require active loading and unloading processes to move nutrients
Xylem vs. Phloem
movement of nutrients
• Xylem
– All nutrients
• Phloem
– High mobility
• Sugars, amino acids
• K, P, Mg, S, Na, Cl
– Intermediate mobility
• Fe, Zn, Cu, Mo, Mn
– Low mobility
Foliar applications of these elements
will only affect the leaves that are
sprayed
• Ca, Si
7
5/9/2012
Where is calcium needed?
• Cell division – crowns
• Cell division – roots –
– highest need occurs at the root tip
Time for some Q&A…
Recent studies regarding foliar fertilization of turfgrass
8
5/9/2012
University of Arkansas
Chris Stiegler
• Does season affect nutrient uptake on creeping bent or bermudagrass greens?
• Do different N sources affect uptake?
• Is foliar N lost due to volatilization
Crop Science 51:1253–1260 (2011)
Crop Science 51:1767–1773 (2011)
University of Arkansas
Foliar Fertilization Research
• Two putting green research areas
– ‘Penn A1’ Agrostis stolonifera
– ‘Tifeagle’ Cynodon dactylon x C. transvaalensis
• Treatments applied from May to September
– Two N rates (0.1 and 0.25 lb. N 1000 ft‐2)
• Measurements include:
– Sequential sampling of plant uptake over time (0, 1, 4, 8, and 24 h) – Tissue and rinsate 15N analysis
– Volatilization over 24 h
9
5/9/2012
Reasoning behind the sampling frequency
• Applied nutrient immediately after mowing (8am)
• At 4 hours (12 pm), superintendent would consider syringing greens
• At 8+ hours (>4 pm), irrigation scheduling would begin
• At 24 hours, mowing
How much foliar‐
applied N gets into the leaf tissue?
• Nitrogen absorption had
generally peaked
between 1 and 4 hours
after application
10
5/9/2012
Mean absorption by month:
May – 85%
June - 70%
July - 60%
Higher rates (0.25 lb) of N
are not absorbed as
completely as low rates
(0.10 lb)
Chemical movement of nutrients through the cuticle
• Diffusion ‐ movement of chemicals from a region of higher concentration to a region of lower concentration
Cuticle wax
Leaf surface
K+
K+
K+
K+ K+ K+
K+
K+ K+ K+
K+
K+
K+
K+
K+
17 K+
ions
K+ K+
Surface cells
K+
K+
K+
K+
K+
K+
K+
7 K+
ions
Ions will move from the higher conc. (left side) to
lower conc. (right side)
11
5/9/2012
Another possible reason… Higher
rates lead to some leaf dessication /
burn and can reduce uptake
0.1 lb N 1000 ft-2
0.25 lb. N 1000 ft-2
Does N form affect uptake of foliar‐applied N?
Foliar N Source Uptake Study
• Various forms of inorganic and organic N included in specialty foliar products
– Little is currently known about absorption efficiency of these individual compounds
• Similar research methodology employed
– 15N‐labeled compounds • Urea, ammonium sulfate, potassium nitrate
• Glycine, glutamic acid, proline
– ‘Penn G2’ Agrostis stolonifera
– Lower application rate (0.1 lb N 1000 ft‐2)
– Sampled at 1 and 8 h after application
12
5/9/2012
Foliar N Source Uptake Study
Nutrient Ion or Compound Absorption Based on Charge
Cations
NH4+
K+
=
Neutral
Urea
>
Anions
NO3PO4-
Leaf surface
Cuticle
GC
GC
Cell Wall
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Transcuticular pores or
slight negative charge in polar pathways
Polar pathways
Are there cost & true differences among foliar products?
13
5/9/2012
USGA Green Section Record
May / June 2010
Example analysis –
Emerald Isle Nutrirational
N Source Demonstration Study
University of Arkansas Turfgrass Field Day – 5 August 2009
14
5/9/2012
N Source Demonstration Study
Product
lb N / 1000
$ / acre
(NH4)2SO4 21-0-0
0.125
7.54
(NH4)2SO4 21-0-0
Emerald Isle Nutri•Rational True Foliar N 19-0-0
Emerald Isle Nutri•Rational True Foliar N 19-0-0
Emerald Isle SeaQuential 7-0-0 + micros
Emerald Isle SeaQuential 7-0-0 + micros
Ferromec AC 15-0-0 + Fe
Ferromec AC 15-0-0 + Fe
Floratine Carbon Power 23-0-0 + Mo
Floratine Carbon Power 23-0-0 + Mo
Gary's Green 18-3-4 + Fe
Gary's Green 18-3-4 + Fe
Griggs Bros. Ultraplex 5-0-3
Griggs Bros. Ultraplex 5-0-3
Knife Plus 12-0-0 + micros
Knife Plus 12-0-0 + micros
0.25
0.064
0.25
0.019
0.25
0.067
0.25
0.07
0.25
0.09
0.25
0.026
0.25
0.032
0.25
15.05
52.67
205.75
43.83
576.76
19.48
72.72
37.18
132.82
70.41
195.57
103.16
991.93
47.81
373.55
KNO3 13-0-46
0.125
16.08
KNO3 13-0-46
Urea 46-0-0
Urea 46-0-0
0.25
0.125
0.25
32.16
3.54
7.08
University of Arkansas Turfgrass Field Day – 5 August 2009
N Source Demonstration Study
Product
lb N / 1000
$ / acre
(NH4)2SO4 21-0-0
0.125
7.54
(NH4)2SO4 21-0-0
Emerald Isle Nutri•Rational True Foliar N 19-0-0
Emerald Isle Nutri•Rational True Foliar N 19-0-0
Emerald Isle SeaQuential 7-0-0 + micros
Emerald Isle SeaQuential 7-0-0 + micros
Ferromec AC 15-0-0 + Fe
Ferromec AC 15-0-0 + Fe
Floratine Carbon Power 23-0-0 + Mo
Floratine Carbon Power 23-0-0 + Mo
Gary's Green 18-3-4 + Fe
Gary's Green 18-3-4 + Fe
Griggs Bros. Ultraplex 5-0-3
Griggs Bros. Ultraplex 5-0-3
Knife Plus 12-0-0 + micros
Knife Plus 12-0-0 + micros
0.25
0.064
0.25
0.019
0.25
0.067
0.25
0.07
0.25
0.09
0.25
0.026
0.25
0.032
0.25
15.05
52.67
205.75
43.83
576.76
19.48
72.72
37.18
132.82
70.41
195.57
103.16
991.93
47.81
373.55
KNO3 13-0-46
0.125
16.08
KNO3 13-0-46
Urea 46-0-0
Urea 46-0-0
0.25
0.125
0.25
32.16
3.54
7.08
University of Arkansas Turfgrass Field Day – 5 August 2009
Table 1. Foliar fertilizer products used in the greenhouse creeping bentgrass test, Auburn, AL.
Analysis
Trade name
Manufacturer name
Nutrients derived from:
(%)*
Emerald Isle Solutions
Lebanon Seaboard Corp.8Nx, 0Py, 4Kz, Calcium nitrate, potassium nitrate, urea, glycine, sodium Nutri∙ Rational TrueFoliar
8Caa, 0.12Bb, borate and kelp extract
0.3Sic
Emerald Isle Solutions
Lebanon Seaboard Corp.10N, 0P, 10K, Ammonium nitrate, urea, ammonium polyphosphate, potassium citrate, potassium carbonate, magnesium Nutri∙ Rational TrueFoliar
0.24Mgd, nitrate, zinc nitrate, manganese nitrate, magnesium 0.06Cue, 0.95Fef, 2Mng, sulfate, copper sulfate, zinc sulfate, ferrous sulfate, iron EDTA and kelp extract
0.08Znh
Suprema
Grigg Brothers
12N, 0P, 12K, Urea, potassium nitrate, phosphoric acid, potassium phosphate, boric acid, iron, zinc, manganese, and copper 0.005B, glucoheptonates
0.05Mn, 0.05Zn
Gary’s Green
Grigg Brothers
18N, 3P, 4K, Urea, ammonium phosphate, potassium phosphate, 0.12Cu, 1Fe, potassium nitrate, iron, zinc, manganese, and copper glucoheptonates
0.10Mn, 0.10Zn
Pro‐Balance
Growth Products
15N, 2P, 15K Urea, methylene urea, potassium carbonate, phosphoric acid
Pro‐Formance Ultra
Growth Products
18N, 3P, 6K, Urea, methylene urea, potassium carbonate, 0.05Ca, 0.5Fe, polyammonium phosphate, iron, manganese, magnesium, zinc EDTAs, enzymatically hydrolyzed soy protein, 0.05Mn, 0.05Mg, saccarides, maltose, dextrin, Yucca schidigera, potassium 0.05Zn
humate, kelp extract
NutriFoliar
Lebanon Seaboard Corp.18N, 2P, 5K, Monoammonium phosphate, urea, dipotassium phosphate, potassium hydroxide, copper sulfate, ferrous 0.1Cu, 1Fe, 0.1Mn, 0.1Zn gluconate, ferrous sulfate, manganese sulfate, zinc sulfate
NutriFoliar
Lebanon Seaboard Corp.18N, 3P, 8K, Urea, urea‐trizone, tetrapotassium pyrophosphate, 2.5S
potassium thiosulfate
Urea
45N 0P 0K
urea
15
5/9/2012
How do spray volume, adjuvants, and tank mixing affect N uptake?
Foliar Nitrogen Uptake Efficiency
of Creeping Bentgrass as
Affected by Spray Volume,
Adjuvants, Tank-Mixing, and
Fertilizer Formulation
Shelby Henning
Bruce Branham
Richard Mulvaney
University of Illinois-Urbana Champaign
Spray Volume Results
6 hr after application
20
40
60
80
100
Spray volume (gal / acre)
16
5/9/2012
Adjuvant Results
6 hr after application
Tank Mixing Results
6 hr after application
Summary Points
• The goal of foliar fertilization is nutrient uptake through foliage (low application rates!)
• 60 to 80% foliar uptake measured when urea applied to putting green turf
– % uptake not affected by season, as long as turf is actively growing
– % uptake increases w/ decreasing spray volume, adjuvants, and was not affected by tank mixing
• Volatilization negligible on putting green turf when typical N rates applied
• Uptake and turf quality similar between urea and specialty foliar fertilizer products
17
5/9/2012
Acknowledgements
Thanks –
any questions ??
Mike Richardson
University of Arkansas
[email protected]
http://turf.uark.edu
18