Nitrogen Sources for Cotton

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Nitrogen Sources for Cotton Across the
Belt
Glen Harris UGA (Tifton)
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Ammonium Nitrate vs. Urea For Cotton Production
in Georgia
Glen Harris University of Georgia (Tifton)
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Nitrogen Sources for 2007
Glen Harris UGA - Tifton
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Industrial N Fixation

• Haber Bosch Process
  
• N2 3H2 gtgtgtgtgtgtgt? 2NH3
  

Heat Pressure
Natural Gas Ingredient Fuel Source
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CaNO3 ? KNO3 ?
Source PPI Soil Fertility Manual
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Choosing an N Source for Cotton
All sources of nitrogen are considered equal in
their ability to provide nitrogen to cotton. No
one form of nitrogen is superior to another if
all are applied correctly. Base choices on
price, availability and ease of
application Mississippi State University
Extension Service
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Comparing Nitrogen Fertilizers
Nitrogen Source Comments
Anhydrous Ammonia Gas Inexpensive Safety/Dealer Insurance Methamphetamines
UAN Solutions Liquid UreaAmmoniumNitrate
Urea Solid Concentrated Volatilization
Ammonium Nitrate Regulations Availability Higher Cost
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Nitrogen Fertilizers Sold in Georgia FY 06
(Tons x 1000)
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Ammonium Nitrate Sold in Georgia
(Tons x 1000)
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Urea Sold in Georgia (Tons x 1000)
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The Comparison
Ammonium Nitrate Urea
Solid Solid
34 N 46 N
Salt Index105 Salt Index75
Safety/Regulations Availability Volatilization
315/ton 0.46/lb N 345/ton 0.38/lb N
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Has Urea Gotten a Bum Rap ?

• Worst Case Scenerio Loss 30
• Not as Good as Ammonium Nitrate ?
• Not as Quick as Ammonium Nitrate ?

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Late Sidedress N Source Expo 2005
Yields (lb lint/a)
a
ab
ab
bc
c
c
d
de
e
e
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Conditions that lead to NH3 loss

• Enough soil water for hydrolysis, but
• not enough to leach urea into soil
• Low pH buffering capacity (low OM)
• High temperatures
• High wind speed

NH
3 gas
-
clay
NH
-
3 gas
OM
-
NH
NH
NH
H
4

4

aq
3 aq

CO(NH
)
2H
O H
2NH
HCO
2
2
2

4

3
-
urease
urea
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How To Limit Volatilization Losses from Urea

• Incorporate Into Soil with Tillage
• Inject Beneath Soil Surface
• Apply in a Band
• Apply When Soil Temp Below 50 F
• Irrigate Shortly After Application
• Pray for Rain on Dryland
• Use a Urease Inhibitors
• Ex. Agrotain

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Fertilizer additive that inhibits degradation of
urea by urease Urease enzyme produced by
soil microbes Does not affect microbes (or
other soil organisms) directly Reduces loss of
surface applied urea-N to volatilization 14-Day
Inhibition period rapid drying conditions
N-(n-Butyl) thiophosphoric triamide aka NBPT
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Net Return (/a) by Rain-Free Days
of Rain-Free Days
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Evaluation of a Urease Inhibitor with Sidedress
Nitrogen in the Southeast
Glen Harris University of Georgia - Tifton
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AGROTAIN vs. N-Serve Urease
Inhibitor Nitrification Inhibitor
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• ESN Environmentally Smart Nitrogen
• Polymer Coated Urea
• Company Agrium
• Controlled Release
• Releases as the Soil Warms
• Corn in Ohio and Canada ( Kentucky)
• Cotton in Georgia - 2006

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Split Applications vs. Slow Release
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2006 ESN vs. Nitrate Sunbelt Expo (Moultrie, GA)
Yields (lb lint/a)
30SR 30SR
30AN 60AN
30SR 60SR
30SR 60AN
30AN 60SR
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2006 ESN vs. Urea Sunbelt Expo (Moultrie, GA)
Yields (lb lint/a)
30U 30SR
30SR 30SR
30SR 30U
30U 30U
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Enhanced Efficiency (EE) Fertilizers
New Term Coined by The Fertilizer Institute (TFI)
products that minimize the potential of
nutrient loss to the environment.
Slow/Controlled Release Absorbed Coated Occluded R
eacted
Stabilized/Additive Nitrification
Inhibitors Urease Inhibitors Stabilizers
Association of American Plant Food Control
Officials (AAPFCO)
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2006 Tetra UAN/CaCl Sunbelt Expo
Yields (lb lint/a)
60 UAN CaCl
0 UAN 0 CaCl
0 UAN CaCl
30 UAN CaCl
60 UAN
30 UAN
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2006 Englehard/Attapulgite Clay Sunbelt Expo
Yields (lb lint/a)
30 Clay
60 UAN
30 UAN
60 Clay
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Poultry Litter The Original Slow
Release Fertilizer
( Biosolids and Legume Cover Crops ?)
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Time for Questions ?