Use of Fertilizer Additives

1. Use of Fertilizer Additives Brian Arnall Department of Plant and Soil SciencesOklahoma State University

2. Isn’t it true…….. • Nitrogen • Not available • NH3 is the devil • Phosphorus • Not available • Around for a long time • Ortho P is better than Poly P

3. Options • They can be added too • N stabilizers/Inhibitors • P stabilizers • Low Salt and fungicides • Replacement off • Coated • Low salt/slow release • Ortho P • Or in Blends • Coated

4. Understanding • Should be applied for a reason • The is a problem • Or potential to increase • Not just because

5. Nitrogen

6. Slow Release • Prevents immediate release into soil where environment and biological’s have impact. • Coated • Chemistry • Inhibitors • Prevent the biological activity that impacts the Nitrogen Cycle • Since early 60’s at least 15 substances thoroughly researched

7. Controlled-Slow Release • Coated Urea’s • Sulfur Coat • Polymer Coat • Urea/N Chemistries • Isobutylidenediurea • Ureaformaldehyde • Urea-Triazone • Methylene Urea

8. Controlled-Slow Release • Advantage of these materials is that one application may provide a uniform supply of N to the plants for several weeks. • S-coated urea (32-36 %N) breakdown of the S coat (physical barrier) Moisture • Polymer Coated UreasESN: Temp and Moist • IBDU(isobutylidenediurea) is synthetic organic. particle size, soil moisture content and pH. • Urea-formaldehyde: microbial & temp • Methylenedi-urea -CoRoN, Dura_N: Microbial & temp • Urea-Triazon- N-Pact, N-Sure: Moist & Microbial. • LOOK AT PERCENT SLOW RELEASE • 6 to 20% • Release Patterns

9. Understanding polymer coating technology • ESN contains a urea granule nitrogen (N) within a micro-thin polymer coating. This coating allows water within the soil to move into the granule and dissolve the urea inside. The urea solution then moves out through the coating into the soil where it is available to the crop. • The rate at which the urea solution moves out through the coating is determined by soil temperature and moisture. In cool soils when the crop is growing slowly, N release is slow. As the soil warms and crop growth increases, the granules release N more quickly and steadily.

10. Low Salt Nitrogen • Yield and Protein Always equal to UAN when used as a fertilizer source. • Reduced amount of Tissue Damage • Increased rate w/ seed possible. Using 10-34-0 • Wheat < 30 lb N i.e. 25 gal/ac • Canola <10 lb N i.e. 8 gal/ac

11. CoRoN at Flag Leaf w/fung Received Humic Acid with Top-dress

12. Stabilizers • Two Target • Keep as Urea • Keep as Ammonia

13. Urea Exp. • Wet Soil 70˚F 0 4 8 • Wet Soil 35˚F 0 8 32 56

14. Urea Exp. 0 8 32 56 • Sub Soil 70˚F • Dry Soil 70˚F 0 4 8 Rain1/2” 0 4

15. UREA H2O: Rain, Mist, Dew, Humidity, Soil Moisture (NH2)2 CO2 NH3(gas) SOIL H2O Urease NH4 SOIL NH4 NH4 NH4

16. N Stabilization • Urease Inhibition • Basically prevents/slows urea’s conversion to ammonia • If ammonia (gas) is formed in absence of moisture or soil surface it will be lost to the atmosphere H2O SOIL (NH2)2 CO2

17. Urease Inhibition • NBPT: Studied since the 80’sAgrotain • 7 Day half life • (MIC) MaleicItaconicCoploymer Ca binding of nickel ions necessary for the formation and function of the enzyme Nutrisphere • Published Results not positive

18. To Use or Not to Use • When less or not beneficial • Incorporated • Rain or irrigation of ½ “ or more • Soil and air temp < 50 • Dry soil and Air • Banding • No rain expected for 14+ days • UAN vs Urea

19. To Use or Not to Use • When more beneficial • Surface applied • No-till • High humidity • Light rains, heavy dews, mists • Soil and air temp > 50 • Wet soil • Soil with high pH >7.5 Lots of OH in soil • Rain within 10 days

20. N Stabilization • Nitrification Inhibition • Basically prevents/slows ammonium’s conversion to nitrate • Ammonium(+) is immobile in the soil Nitrate(-) is mobile. In high rainfall, irrigated, well drained soil NO3 is easily lost. • NO3 can be lost by leaching and Denitrification • Both Take WATER!!!!

21. Nitrification

22. NO3 Losses

23. Nitrification Inhibition • Nitrapyrin- Registered Pesticide, studied since the 60’s N-Serve, Instinct • (MIC) MaleicItaconicCoploymer Ca binding of nickel ions necessary for the formation and function of the enzyme Nutrisphere • DCD – Suppresses, does not kill nitrosomas, Agro+, SuperU • Ammonium-Thio-Sulfate: Low pH keep NH4 from going to NH3, short lived.

24. To Use or Not to Use • When less or not beneficial • Arid environments • Well drained soils that allow infiltration but have limited leaching

25. To Use or Not to Use • When more beneficial • Tile Drainage • Wet soils • Irrigated fields

26. Phosphorus • Chemically “Charged” • Binds with Iron, Aluminum, Calcium • Oklahoma Soils high in ALL of these. • Average down state Ca, 6000lbs avail. • Phosphorus Fertilizer and the Soil • Common commercial P fertilizers are highly (≥90%) water soluble

27. Poly vs. ortho • In general, P in dry fertilizers such as 18-46-0 and 11-52-0 P is orthophosphate. • P in common fluid fertilizers such as 10-34-0 and 7-21-7 is present as both orthophosphate & polyphosphate. • Approximately 2/3 of the P is present in the Poly and The remainder is Ortho • Some fluids such as the 9-18-9 have all of the P as Ortho • The effect of both forms of P on crop production has been evaluated in various field trials throughout the Corn Belt. • The results from a study with corn in Nebraska are summarized in the following table.

28. The effect of polyphosphate and orthophosphate on corn yield Source: University of Nebraska ave of 5 sites; low P test

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30. Summary from P • You should not base choice of fertilizers on orthophosphate or polyphosphate claims. • Buy the source that best fits your needs and is the cheapest per lb of nutrient.

31. P stabilizer • Avail®, which is marketed as a phosphate enhancing product, contains the same active ingredient as Nutrisphere. The Avail activity is attributed to binding of calcium or iron ions in the soil normally bind p. • AI of Nutrisphere/Avail, the compound is highly negatively charged and would tend to bind with any compound with a positive charge, not distinguishing one ion over another.

32. OK State Research Results

33. OK States Work • Avail Studies in Wheat (Not Published) • Arnall, 3 years 2 sites per year. No positive. • Agrotain in Wheat (Published) • Arnall, No positive yield responses • Edwards, 1 out of 2 yrs positive. • Slow release N’s. Wheat and Corn. • Just as good as UAN or Urea. • NUE Sorghum (Not Published, ongoing) • ESN, SUPERU, Agrotain • Banded UAN in 2” x 2” UAN+Agrotain Plus & UAN + Nutrisphere Caused Stand Problems.

34. Ok States Work • Southern Water Group (On table) AR, AL, FL, NM, NC, OK, TX • There were few differences due to N fertilizer sources or additives for the soils, crops, or environmental conditions evaluated. • Nutrisphere®, Nitamin® and Agrotain® did not improve yields at any location for any crop where tested. Pre-plant incorporated ESN (as compared to urea) improved the corn yield at one site in Arkansas. When tested at two sites in Arkansas, ESN improved seedcotton yield at one site but produced yields equal to urea at the second site. • Preplant incorporated ESN® performed better than urea on corn in Arkansas and cotton in one of the two sites in Arkansas. The ESN® performed similarly or worse than UAN solution or urea in Alabama (corn), North Carolina (corn and wheat), Oklahoma (wheat) and Texas (grain sorghum).

35. Peer Reviewed Pubs List on back tableNPK.okstate.edu

37. Thank you!!! www.extensionnews.okstate.edu Brian Arnall 373 Ag Hall 405-744-1722 b.arnall@okstate.edu Presentation available @ www.npk.okstate.edu Twitter: @OSU_NPK YouTube Channel: OSUNPK