Nitrogen Sources for Cotton Across the Belt Glen Harris – UGA (Tifton)

Ammonium Nitrate vs. Urea For Cotton Production in Georgia Glen Harris University of Georgia (Tifton)

Nitrogen Sources for 2007 Glen Harris UGA - Tifton

N2 + 3H2 >>>>>>> 2NH3 Industrial N Fixation Haber Bosch Process N2 + 3H2 >>>>>>> 2NH3 Heat + Pressure Natural Gas = Ingredient + Fuel Source

CaNO3 ? KNO3 ? Source: PPI Soil Fertility Manual

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

Comparing Nitrogen Fertilizers Nitrogen Source Comments Anhydrous Ammonia Gas Inexpensive Safety/Dealer Insurance Methamphetamines UAN Solutions Liquid Urea+Ammonium+Nitrate Urea Solid Concentrated Volatilization Ammonium Nitrate Regulations Availability Higher Cost

Nitrogen Fertilizers Sold in Georgia – FY 06 (Tons x 1000)

Ammonium Nitrate Sold in Georgia (Tons x 1000)

Urea Sold in Georgia (Tons x 1000)

The Comparison Ammonium Nitrate Urea Solid 34 % N 46 % N Salt Index=105 Salt Index=75 Safety/Regulations Availability Volatilization $315/ton $0.46/lb N $345/ton $0.38/lb N

Has Urea Gotten a Bum Rap ? Worst Case Scenerio Loss = 30 % Not as Good as Ammonium Nitrate ? Not as “Quick” as Ammonium Nitrate ?

Yields (lb lint/a) Late Sidedress N Source – Expo 2005 a ab ab bc c c

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 - urea urease

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

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

Net Return ($/a) by “Rain-Free Days” # of Rain-Free Days

Evaluation of a Urease Inhibitor with Sidedress Nitrogen in the Southeast Glen Harris University of Georgia - Tifton

AGROTAIN vs. N-Serve Urease Inhibitor Nitrification Inhibitor

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

Split Applications vs. Slow Release

Yields (lb lint/a) 2006 ESN vs. Nitrate Sunbelt Expo (Moultrie, GA) 30SR 60AN 30AN 60SR 30SR 30AN 60AN 30SR 60SR

Yields (lb lint/a) 2006 ESN vs. Urea Sunbelt Expo (Moultrie, GA) 30SR

“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 Reacted Stabilized/Additive Nitrification Inhibitors Urease Inhibitors Stabilizers Association of American Plant Food Control Officials (AAPFCO)

Yields (lb lint/a) 2006 Tetra UAN/CaCl Sunbelt Expo 0 UAN 0 CaCl 0 UAN

Yields (lb lint/a) 2006 Englehard/Attapulgite Clay Sunbelt Expo 30 UAN

The “Original” Slow Release Fertilizer Poultry Litter The “Original” Slow Release Fertilizer (+ Biosolids and Legume Cover Crops ?)

Time for Questions ?