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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. Industrial N Fixation.
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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
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
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)
Has Urea Gotten a Bum Rap ? • Worst Case Scenerio Loss = 30 % • Not as Good as Ammonium Nitrate ? • Not as “Quick” as Ammonium Nitrate ?
Late Sidedress N Source – Expo 2005 Yields (lb lint/a) a ab ab bc c c d de e e
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 + aq 3 aq + 4 + CO(NH ) + 2H O + H 2NH + HCO 2 2 2 + 4 + 3 - urease urea
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 ofurea 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
2006 ESN vs. Nitrate Sunbelt Expo (Moultrie, GA) Yields (lb lint/a) 30SR 30SR 30AN 60AN 30SR 60SR 30SR 60AN 30AN 60SR
2006 ESN vs. Urea Sunbelt Expo (Moultrie, GA) Yields (lb lint/a) 30U 30SR 30SR 30SR 30SR 30U 30U 30U
“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)
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
2006 Englehard/Attapulgite Clay Sunbelt Expo Yields (lb lint/a) 30 Clay 60 UAN 30 UAN 60 Clay
Poultry Litter The “Original” Slow Release Fertilizer (+ Biosolids and Legume Cover Crops ?)