fertilize to save money
DESCRIPTION
This is the presentation given by Dr. Jason Kruse at the Golf Industry Show in Las Vegas, NV on February 29, 2012TRANSCRIPT
Jason Kruse, Ph.D. University of Florida
Situation
• Prices for many products have risen steadily – Revenue increases have not kept pace
• Reduced budgets have resulted in staffing cuts
• Increasing demands placed on existing facilities – Events
– People
• Increasing expectations regarding aesthetics and play
Situation
• Expectations – Reduce/eliminate pesticides
– Reduce/eliminate fertilizers
– Organic???
• Goals – First and foremost – Safe,
playable surface!
– Make sure the turfgrass is not a point of discussion
Overview
• Role of nutrients in plant growth
• Fertilizer carriers - Nitrogen
• Cultural management practices
• Fertilizer price trends, predictions, purchasing recommendations
Role of Nutrients in Plants
Plant Nutrition
• An actively growing turfgrass plant is 75 - 85% water. – The remaining 15 - 25% of the plant’s weight is dry matter.
• Sixteen (16) elements are essential because a plant cannot successfully complete its life cycle without them.
• A major portion of the plant dry matter content consists of three (3) elements: – Carbon
– Hydrogen
– Oxygen
6
Plant Nutrition
• Plants obtain carbon and oxygen from the atmosphere.
– Carbon dioxide (CO2), a gas, enters the leaves through the stomata.
– Water (H2O) taken in by the roots supplies hydrogen and oxygen.
7
Essential Elements
• Macronutrients
– Nitrogen (N)
– Phosphorus (P)
– Potassium (K)
• Secondary
– Calcium (Ca)
– Magnesium (Mg)
– Sulfur (S)
• Micronutrients
– Iron (Fe)
– Manganese (Mn)
– Boron (B)
– Copper (Cu)
– Zinc (Zn)
– Molybdenum (Mo)
– Chlorine (Cl)
8
Macronutrients – Nitrogen (N)
• Present in the greatest quantities: 2 – 5% in dry leaf tissue.
• Sufficiency Ranges: – Creeping Bentgrass = 4.5 – 6.0%
– Kentucky Bluegrass= 2.6 – 3.5%
– Ryegrass = 4.5 – 5.5%
– St. Augustinegrass = 2.0 – 3.0%
– Zoysiagrass = 2.0 – 3.0%
– Bermudagrass = 2.5 – 3.5%
9
Macronutrients – Nitrogen (N)
• Major impact on a number of factors:
– Effects on plant growth and metabolism, influencing grass response to a number of environmental stress conditions;
– Potential environmental implications;
– Must be routinely applied for a healthy, stress-tolerant turf;
– Accounts for the highest cost of a turfgrass fertilization program.
10
11
Macronutrients – Nitrogen (N)
• N Compounds in Plants - taken up as NO3-
(nitrate) and NH4+(ammonium).
– Amino acids – building blocks for proteins.
– Proteins
– Chlorophyll – photosynthesis
– Hormones - auxins, cytokinins, and ethylene.
– Nucleic Acids - DNA, RNA
12
Nitrogen Deficiency
• The most common nutritional deficiency
• Growth slows dramatically
• Oldest leaves first become chlorotic (lose their dark green color, become yellowish), while newest leaves stay green.
– Nitrogen is transferred from the oldest, expendable leaves to the newest, most valuable leaves
13
14
15
Macronutrients – Phosphorus (P)
• Present in the soil solution in very low concentrations and uptake is primarily as H2PO4
- (pH<7.0), HPO42- (pH>7.0), or certain
soluble organic phosphates.
• Phosphorus content of turfgrass shoot tissues may range from 0.10 to 1.00% by dry weight.
– Sufficiency range is 0.15 – 0.5%.
16
Macronutrients – Phosphorus (P)
• Uses in the plant: – Component of the energy molecules ATP and ADP.
• These compounds serve to store and transfer available energy within the plant.
– Structural constituent • Phospholipids • Phosphoproteins • Nucleic acids • Sugar phosphates • Nucleotides • Coenzymes
17
Macronutrients – Phosphorus (P)
• Visual Symptoms of deficiency
– Initially show up as reduced shoot growth and a dark green color.
• As P deficiency continues, lower leaves may turn reddish at the leaf tips and then progress down the blade.
• Stunted growth - caused by limited P for energy transformations.
• Element of impairment
18 Photo credit: Rosa Say
Macronutrients – Phosphorus (P)
• Applications should be based on soil/tissue test results
Macronutrients – Potassium (K)
• Taken up and stored as the ionic (K+) form.
• Shoot tissue concentration of 1.0 to 3.0% by weight.
• Used in the plant: – Enzymes activator
– Most important solute in the vacuole • Osmoregulation = water regulation in plants
– Used in carbohydrate, amino acid, and protein synthesis
20
Macronutrients – Potassium (K)
• Visual symptoms of deficiency
– Interveinal yellowing of older leaves (lower), followed by dieback of leaf tip, scorching or firing of the margins, and total yellowing of the leaf blade including the veins.
– May appear weak or spindly.
– Under high evaporative demand, wilting and leaf firing may be accelerated as well as wear injury in high traffic areas.
21
Macronutrients – Potassium (K)
• Deficiencies result in:
– Increased respiration and transpiration
– Reduced environmental stress tolerance
– Increased disease incidence
– General reductions in growth
22
Bottom Line
We must maximize our benefit of management practices to ensure a safe,
enjoyable facility for our customers
Nitrogen Fate
• What are some of the potential fates for N applied to a turf surface?
– Taken up by grass
– Microorganisms
– Denitrification
– Volatilization
– Leaching
Sources of Nitrogen
• Fertilizer
• Returned Clippings
• Organic Matter
• Lightning (precipitation)
Consider the Whole System!
• What can you change in your current system to further reduce N need?
– Mowing
– Irrigation
– Fertilization
– Equipment repair/replacement
– Inventory management
– Employees
Mowing/Maintenance
• Increase mowing height
– Increase root depth and photosynthetic capacity
• Reduce highly maintained areas
– Reducing fairway width/length to emphasize landing areas
– Reduce/Eliminate flower beds/ornamentals
– Fairways vs roughs
Seasonal Growth
28
Irrigation
• Conduct irrigation audit
• Ensure application rate/amount does not exceed infiltration
• Match irrigation to weekly ET rates, accounting for rainfall received
– On-site weather station
– http://fawn.ifas.ufl.edu
• Irrigation + rainfall should not wet profile below rootzone, only refill it!
Soil Compaction
• Compacted soils
– Reduced pore space = reduced root growth = reduced N uptake
– Decreased infiltration increases risk of runoff
• Monitor compaction, vary method/depth of aerfication
Consider Your Fertilizer Material
Quickly Available N
• Very soluble
• Rapid response
• Short response
• Cheap
• Minimal temperature dependency
• High leaching potential
• Tendency to burn
Quickly Available N
• Ammonium nitrate 33-0-0
• Ammonium sulfate 21-0-0
• Ammonium phosphates
– mono-ammonium phosphate 11-48-0
– di-ammonium phosphate 20-50-0
• Potassium nitrate 13-0-44
• Urea (organic?) 46-0-0
Slow Release Nitrogen Sources
• Slow initial response
• Longer response than quick release
• Some, but not all, are dependent on temperature for N release
• Low burn potential
• Moderately expensive to expensive
• Less N leaching
Why Use Slow Release Fertilizers?
• More uniform growth response
• No growth surge
• Longer growth response
• Less chance of burn
• Less leaching of nitrate
• Labor saving
Uncoated Slow Release Fertilizers
• Urea formaldehyde (UF)
• Methylene urea (MU)
• Isobutylidene diurea (IBDU)
• Natural organics
Ureaform and Methylene Urea
• Very similar materials chemically
• Mostly granular, some liquids
• about 40% N, 70% WIN (28% N for liquids, all soluble)
• Formed by reacting urea and formaldehyde = chains of alternating C and N
• Main difference is chain length, and as a result, mineralization rate
Products
• Formolene 30-0-2
• FLUF 18-0-0
• Nitro 26 CRN 26-0-0
• Nitroform (Powder Blue, Blue Chip) 38-0-0
• CoRoN 28-0-0
– (25% of total N is urea)
Different Chain Lengths
Methylene Urea N-C-N
N-C-C-C
N-C-C-C-C
N-C-C-C-C-C-C-C
Urea Formaldehyde
N-C-N
N-C-C-C-C-C-C-C
N-C-C-C-C-C-C-C-C-C
N-C-C-C-C-C-C-C-C-C-C-C-C
N-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C
Ureaform and Methylene Urea
• Designed to release N for 8-12 weeks
• Contains unreacted urea, fast greening
• Requires soil microbial activity
– temperature sensitive, soil at 78o F is four times as active as soil at 42o F
– moisture sensitive
• Seasonal response
Nitroform
• Urea formaldehyde
• Insoluble organic
• 38% N; 65-71% WIN
• Biological N release
– Rate influenced by soil temperature
Nutralene
• Methylene urea
• 40% N; 38% WIN
• Biological N release
• More rapidly available than UF
• Not as adversely influenced by cool temperatures
IBDU
• Urea is reacted with isobutyraldehyde
• Only a single chemical product is formed, not a bunch of different molecules. 31% N, 90% WIN
• Different sized granules available
• N release depends on solubility and hydrolysis (IBDU molecule reacts with water and breaks apart), releasing urea.
• No free urea in IBDU, may need to add
IBDU
• Urea breaks down quickly to NH4
• IBDU is relatively insoluble, so only small amounts are available at any one time
• Release sensitive to soil moisture, less on dependant on temperature
• Release also depends on granule size and contact with soil. Smaller granules release N faster than larger granules
IBDU
• 31% N -90% WIN
• N released by hydrolysis
• Relatively unaffected by – Temperature
– pH
• Particle size important
• Excellent cool season response
Liquid Slow Release Fertilizers
• Chemistry similar to UF, MU
• Micro-suspension of MU (FLUF)
• CoRoN, N-Sure; 28%N, 7% as urea and 21% as short chain MU or small ring structure.
• Get quick and slow release
• Foliar application?
• Is slow release slow enough?
Liquid Slow Release Fertilizers
• Easily handled, applied
• Can be formulated with P and K
• Some have short storage life
• Require specialized delivery system
• Volume of liquid used in application is not enough to move the material down into the root system - must irrigate in
CoRon
• 28% N solution
• Polymethylene ureas and amine modified polymethylene ureas
• N release dependent upon microbial action
N-Sure
• 30% N
• Ring structured Triazones may contain methylene diurea
• N release by microbial action
• Response very similar to CoRon
Coated Slow Release Fertilizers
• SCU, sulfur coated urea
• Polymer coated urea
• Poly Coated Sulfur Coated Urea
Sulfur Coated Urea
• Molten sulfur (S) sprayed on urea in rotating drum, coated in wax sealant
• Experimentally produced in 1950’s, commercially in 1972
• N release determined by: – Coating thickness – Microbial degradation – Temperature – Moisture – Coating failure (cracks, abrasion)
Sulfur Coated Urea
• 32-38% N
• Release depends upon – Thickness of sulfur coating
– Biological activity
– Soil environment • Temperature
• pH
• Cool temperature response erratic
• Coating fragile, uneven
Polymer Coated Urea
• Solid urea or other nutrient core, coated with various polymers (“plastics”)
• Coatings are tough, resist damage, thin • Coating chemistry affects membrane
properties, release rate • Release is due to controlled diffusion, which is
fairly constant over time • Release depends on coat thickness, chemistry,
temperature, moisture
Polyon
• 40% N
• Polyurethane coated urea
• N release influenced by – Coating thickness
– Diffusion rate
– Soil temperature
• Good for both warm and cool season
• Coating is abrasion resistant
Poly-S
• Coated with sulfur and a polymer – Cheaper than regular
polymer coated fertilizers
• Release dependent on
– Temperature
– Soil moisture
Fertilizer Programs
• Minimum of 30-50% slowly available N is appropriate – Choose CRN source based on environmental
conditions, budget, level of traffic
• 4-10 lbs N/M annually, depending on level of use/traffic – Do not apply more than 1 lb soluble N/M at one time – Carefully consider use of coated products in high traffic
areas due to potential damage to coating
• Late fall application of IBDU has been shown to improve spring color
Consider site-specific management
PERCENT N RELEASED OVER TIME FOR SELECTED
CRN MATERIALS
7 14 28 42 56 84 112 140 1800
20
40
60
80
100
NITROFORM NUTRALENE MILORGANITE
POLYON SCU AN
Weeks of “Greening”
Nitrogen Source Application Rate Weeks Greening
Urea 1 4
Ammonium Sulfate 1 4
POLYON Regular 1.25 12
Nutralene 1.5 12
Nitroform 2 16
IBDU 1.5 12
Relative Product Price
Nitrogen Source Analysis $/ton $/lb N
Urea 46-0-0 700 0.76
Ammonium Sulfate 21 - 0 - 0 300 0.71
POLYON Regular 43 - 0 - 0 1,500 1.74
Nutralene 40 - 0 - 0 1,300 1.63
Nitroform 38 - 0 - 0 1,500 1.97
IBDU 31 - 0 - 0 1,500 2.42
Smart Purchases
Why is Nitrogen Fertilizer so High Priced?
• High prices have coincided with spikes in price of gas
• Fertilizer shipping costs are important
– U.S. imports more than 8 million metric tons of Nitrogen fertilizer annually
• Natural gas is used to manufacture N-fertilizers
Why is Nitrogen Fertilizer so High Priced?
N2 + CH4 + H2O
Nitrogen (atm) + Natural gas
Heat
Pressure
Anhydrous Ammonia
2NH3 + CO
Why is Nitrogen Fertilizer so High Priced?
+ Nitric acid
Anhydrous Ammonia
+ CO2
Urea Ammonium Nitrate
+ Sulfuric
Acid
Ammonium Sulfate
Price Volatility
• Price for fertilizers spiked in 2008/2009
– Spike in natural gas prices
0
2
4
6
8
10
12
Jan
-19
73
Feb
-…
Mar
-…
Ap
r-1
97
6
May
-…
Jun
-19
78
Jul-
19
79
Au
g-…
Sep
-…
Oct
-19
82
No
v-…
De
c-…
Jan
-19
86
Feb
-…
Mar
-…
Ap
r-1
98
9
May
-…
Jun
-19
91
Jul-
19
92
Au
g-…
Sep
-…
Oct
-19
95
No
v-…
De
c-…
Jan
-19
99
Feb
-…
Mar
-…
Ap
r-2
00
2
May
-…
Jun
-20
04
Jul-
20
05
Au
g-…
Sep
-…
Oct
-20
08
No
v-…
De
c-…
U.S. Natural Gas Wellhead Price
Data 1: U.S. Natural Gas Wellhead Price(Dollars per Thousand Cubic Feet)N9190US3 U.S. Natural Gas Wellhead…
Price Volatility
• While prices have stabilized, futures prices trend upwards through 2016
• Price of natural gas is only a small piece of the picture…
Fertilizer Consumption
Millions of metric tons consumed annually
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
2002 2003 2004 2005 2006 2007 2008 2009 2010
US
China
Effect of Demand on Price
Volatile Prices
Volatile Prices
• Fertilizers
– As much as 85% of variable expenses
– Prices increased dramatically
• Nitrogen and Phosphorus – 300-400% increase from 2002-2008
– Within year price changes over past 3-4 seasons:
• +/- $100/ton for anhydrous ammonia seasonally
• +/- $500/ton for phosphorus seasonally
Source: Kenkel, P. and T. Kim. 2009. Optimal cash purchase strategies to reduce fertilizer price risk. Southern Agricultural Economics Association Annual Meeting, Atlanta, Georgia, January 31 – February 3, 2009.
Volatile Prices
• With so much within year variability, time of purchase is critical!
– Price is driven by world market
– Suppliers stockpile fertilizer for peak demand
– Dealers attempt to shift risk through advance purchase programs
– It is possible to save as much as 16% if purchased at correct time of the year
Volatile Prices
• Best time of year to purchase
– Urea: 1st or 2nd week in July
– Phosphorus: 1st week in November
• Highest prices
– Urea: March/April
– Phosphorus: March
Summary
• Proper nutrient management is essential • Careful management of cultural practices can
have significant impact on effectiveness of N applications
• Important to understand differences in fertilizer materials/use
• Slow release fertilizers have potential to save time/labor and wear on equipment
• Budget savings can be realized through scheduled purchases of fertilizer materials