Site-Specific 4R Considerations When Using Enhanced Efficiency Fertilizers

Transcription

1 Site-Specific 4R Considerations When Using Enhanced Efficiency Fertilizers Mario Tenuta Department of Soil Science Soil Ecology University of Presentation to AgInfo Conference St. Louis, MI July 17, 2018

2 The Professor Managing Fertilizer is Complicated The Ag Retailer The Internet Crop requirements Soil and plant sample interpretation Crop prices Fertilizer prices Application logistics and costs Choice of Nitrogen fertilizer products When to apply Where to apply How much to apply The Extension Agent You want to end up doing as last year

3 Confusion

4 Marvel Entertainment Not Silver Bullet Useful Used Properly

5 Major Nitrogen Fertilizer Loss Pathways Ammonia Volatilization Nitrate Leaching N 2 O + Denitrification Complex Weather dependent Soil dependent Practice dependent Time of year dependent

6 Major Losses of Fertilizer Nitrogen

7 Ammonia Volatilization Loss of Fertilizer N Added % N Loss On average, 18% N added volatilized In North America Pan et al. 2016

8 Leaching of Fertilizer N % N Loss Incorporated Injected Surface applied On average, 8% N added leached Yield Mg/ha Incorporated Injected Surface applied Christianson and Harmel, bu/ac 300 bu/ac 200 bu/ac Why lowest yield with surface? Additional losses with volatilization

9 Denitrification Losses of Added Fertilizer N % Soil Organic Matter Excessively Well Drained Well Drained Moderately Well Drained Somewhat Poorly Drained Poorly Drained < > Meisinger and Randall, 1991 Need warm soil temperatures to get this sort of losses Source: Dupont/Pioneer

10 4R Nutrient Stewardship Best use of crop nutrient additions Improve/maintain yields Improve profitability Limit losses Have co-benefits (water and air quality, GHG) Understandable and easy to follow Auditable, provide credits, use $incentive programs Applies agronomic sense of past, present and future advances

11 Enhanced Efficiency N Fertilizers Stabilized N o Urease inhibitor o Nitrification inhibitor o Double inhibitor Controlled Release o Polymer Coated Urea Slow Release o Sulfur-coated Urea, Methylene Urea, Isobuylidene Diurea, Urea Formaldehyde, Urea Triazone

12 Nitrification Lower Volatilization Losses Lowers Appearance of NO3 - Denitrification NH 4 X X Enhanced Efficiency Fertilizers Enhanced Efficiency Fertilizers X Mechanism of Action NH 3 NH 2 OH NO 2 - NO 3 - N 2 O N 2 O N 2 O Urea 1. Nitrification Inhibitors 2. Urease Inhibitors 3. Controlled and Slow Release Urea N 2

13 Polymer Coated Urea Release of urea to soil Depends on Soil moisture Soil temperature Soil contact (subsurface) Nutrien Inc.

14 Ammonia Gaseous loss of fertilizer Nitrogen Prone to loss with Anhydrous ammonia if injected shallow, slots not covered, especially sand soil Ammonia producing sources such as urea granular and solution applied to soil surface Ammonium and urea with basic reacting phosphate fertilizers applied to soil surface or shallow bands Losses more pronounced when warm, soil wet, air dry, lots of wind Losses more pronounce on soil that is basic (ph>7), low organic matter, sandy, low buffering ability

15 Ammonia Volatilization from Urea Urease Enzyme NH 4 + HCO 3 - NH 4 + CO 2 OH - NH 3 High ph HCO 3- + H 2 O CO 2 + OH - + H 2 O What Promotes Volatilization? Low organic matter Sand Low CEC High urea concentration Relative Concentration Moisture Wind Temperature ph NH 3 NH 4 +

16 How Deep Placement Reduces Ammonia Volatilization from Urea NH 4 + HCO 3 - Deeper the incorporation more opportunity for acidity from organic acids and reserves on clay to neutralize bicarbonate and ammonia Ammonium held to clay and organic matter NH H 4 N - NH 4 + HCO3 - HCO 3- + H 2 O + H + CO 2 + 2H 2 O Acidity from Organic acids Reserve acidity of clays

17 How Shallow Placement May Increase Ammonia Volatilization from Urea Surface Broadcast Shallow Banded NH 4 +HCO 3 - NH 4 + NH 4 + HCO - 3 High concentration in band produces very high concentrations of CO 2 OH - High ph ammonium and bicarbonate High concentrations of bicarbonate breaks down to CO 2 and high amount of base High amount of base converts ammonium to ammonia NH 3 For shallow banded, less volume of soil to buffer before ammonia gets to atmosphere

18 How Urease Inhibitor Reduces Ammonia Volatilization Slower release of NH HCO 3 - Less ph Increase NH4+ increased chance to bind and move in soil Less Volatilization Urease Enzyme BMPT NH 4 + HCO3 - NH 4 + CO 2 OH - NH 3 High ph BMPT Urease Enzyme HCO 3- + H 2 O CO 2 + OH - + H 2 O

19 Shallow Banding Ammonia Loss Concern For Northern Great Plains of Canada Standard recommendation is subsurface band to >3 Increasing use of shallow banding Saves time Saves fuel Some evidence in Eastern Canada that ammonia losses may be higher for shallow banding than surface placement of granular urea

20 Surface Shallow Banded Surface Incorporated Ammonia Loss Study Near Quebec City Silty clay loam (27% clay) 125 lbs N/acre 20 band spacing 5 cm depth hand trenched band Rochette et al. JEQ 2009

21 Ammonia Loss From Shallow Band Urea Increases with N Rate % Loss lbs N/ac equivalent for 16 band spacing 180 6% Loss 90 2% Loss Silty loam (19% clay) 146 lbs N/acre 20 band spacing 5 cm hand trenched band Rochette et al. CJSS 2013

22 Deeper Band Placement Reduces Ammonia Loss Ammonia losses are nil if placement below 3 Loss as % of Surface Placement 55% 33% Data from 15 published studies 13% Rochette et al. JEQ 2014

23 Canola Yield in Manitoba Trials with Placement N Rate Not Optimum (70% of Recommended) bu / acre 60 Broadcast surface urea lower yield than subsurface Ammonia loss problem 50 b a a Surface Shallow Band Deep Band 10 0 Placement *no effect of N source or placement x source interaction

24 bu / acre Canola Yield in Manitoba Trials N Rate Optimum (100% of Recommended) No difference in placement when N rate is optimum, Means loss of ammonia with surface placement is covered Up by extra Nitrogen addition Surface Shallow Band Deep Band 10 0 Placement *when N rate optimum, no effect of placement *no effect of product or product x placement interaction

25 Assessing Ammonia Loss with Dosimeters Agrotain Urea Surface Granular Urea

26 Ammonia Loss Carman Manitoba 2015 Sandy Loam Soil with Low SOM Cumulative Ammonia Captured Parts Per Million Site year with most ammonia loss Surface Urea Benefit Surface SuperU Shallow SuperU Shallow Urea Control Deep Urea Deep SuperU Day

27 Ammonia Loss Domain, Manitoba 2016 Clay Soil with Very High SOM 9 Site year with least ammonia loss Cumulative Ammonia Captured Parts Per Million Low volatilization potential and no benefit to inhibitors 0 Day

28 Summary of EEFs on Volatilization Benefit Urease Inhibitors Benefit Controled Release No Benefit Of Nitrification Inhibitors Alone

29 Don t waste time and money buying urease inhibitor alone and apply subsurface to soil

30 Nitrous Oxide (N 2 O) IPCC AR5, Joseph Priestley Sources: VO_C30_NOS_TANKS.jpg.html

31 Whenever Ammonia, Ammonium and Urea Fertilizers added Nitrous Oxide Emissions Occur F = fertilizer addition T = Thaw emission = fertilizer emission Corn Fababean Spring Wheat Rapeseed Barley Spring wheat Corn Soybean FN (g N ha -1 d -1 ) Corn Fababean Alfalfa Alfalfa Alfalfa Alfalfa Corn Soybean F F F F F F T T T T T T T T May Nov May Nov May Nov May Nov May Nov May Nov May Nov May Nov May Month

32 What EEFs Do to Limit N 2 O Losses? N 2 O emissions occur After fertilizer application following rains Over the winter when soil is wet and crop growth is low Where soil freezes, when soil thaws EEFs can only be expected to reduce emissions following fertilizer addition Other reductions need to be managed by other practices such as minimize residual soil nitrate after harvest, reduce soil moisture

33 Placement N 2 O emissions-2011 Wheat Manitoba N 2 O, kg N 2 O-N ha Fertilizer More Rains After Application Carman - sand soil Day of Year Urea I Urea S Urea M ESN M SuperU M Control N treatment N 2 O (kg N 2 O-N ha -1 ) Control Urea I Urea S Urea M ESN M SuperU M 0.55 d 1.82 a 1.55 a 1.31 ab 0.97 c 0.98 c Less Rains After Application Oak Bluff - clay soil Fertilizer I=incorporated S=sideband M=midrow band Day of Year Banding tends to reduce EEF 26% less than urea when banded Gao et al Agron J

34 Irrigated Potato Carberry Manitoba Double banded ESN benefit in wet year when subsurface bandef Dry Year Early Wet Season Year Gao et al. 2016

35 Leaching Prevention NO 3 - Marine System

36 Leaching is Primarily Issue of Excess N Added Dry Wet N in Water Corn Yield

37 Little Impact of Timing of N Application on Leaching N Timing N rate Corn Yield Dissolved N Kg N ha -1 Mg ha -1 Kg N ha -1 Well before planting Before planting At planting Dress after planting

38 EEFs be Useful to Prevent Leaching in Some Circumstances Early season when nitrification as converted N to nitrate but crop growth hasn t kicked in full gear Stabilized nitrogen and controlled release nitrogen can reduce the appearance of early nitrate and thus leaching in early growth season

39 Wrapping It Up You have lots of considerations to optimize nitrogen fertilizer use Enhanced efficiency fertilizers are a tool to help out Not a tool that all ways works or that you need But a tool to go along with other management options Know your soil and how it loses nitrogen Know how much your crop doesn t take up nitrogen Know your main loss of nitrogen Can EEF Nitrogen fertilizers reduce those main loses? Is there a 4R practice that can reduce your loss without EEF? If not, will EEF work for your situation Pay attention to the economics, EEFs cost more, need a return

40 Soil Ecology University of Manitoba Acknowledgements Dr. Tai McClellan Maaz and IPNI for invitiation Those who did the work: Dr. Kevin Baron, Xiaopeng Gao, Brad Sparling, Merv Bilous, Greg Wiebe, Natasha Klassen, Morgan Hope, Andrew Hector, Ian Copps, Marliese Peterson Those who funded the work: Fertilizer Canada, MCGA, Agrium, KOCH Agronomics, CARP, Western Grain Research Foundation, AAFC, NSERC Discovery Grant Program, Canada Research Chair Those who provided land: many