Methods to estimate NH3 emission from field-applied cattle slurry              I. Wind tunnels   II. Micrometeorological m...
Wind tunnels (Misselbrook et al. 2005)• the turbulence of the air drawn through a wind  tunnel may be quite different from...
Field: Ferm et al. (2000)   NH3 concentration at 20 cm height: ~ 1/10 * Ceq
Wind tunnel (2010)NH3 concentration at 20 cm height: ~ 1/500 * Ceq (~ 50 times lower!)
Sommer (2003)Overestimation wind tunnel: about a factor 2
Sintermann (2012)Wind tunnels * ½ ->
Conclusion IAmmonia fluxes measured in wind tunnels(forced inflow of clean air; very small emittingarea) are per definitio...
Effects of wind speed and radiation           (Sommer 2003)
Effects of temperature and wind speed   (adapted from Schjoerring et al. 1993)                                 ammonia.prn...
Conclusion II- No clear effects of wind speed on NH3emission in the open field: interaction withtemperature and incoming s...
Micrometeorological methods- Mass balance method- Integrated horizontal flux method  (r is the fetch)As far as we know onl...
Schjoerring et al. (1992): comparsion of direct (from    beakers) and indirect measurements (MBM)M    Mass balance method:...
Mobile Lidar SystemBerkhout et al. (2008)
Conclusion IIITwo evaluations of the MBM in the field with artificial NH3 sources (knownreleased amounts) revealed that th...
Passive flux samplers (Winsum 2012): height 20 cmfetch 100 – 150 m (point 1 close to field border upwind)
Conclusion IV- Over distances of a few tenths of meters on  average only a small increase in NH3  concentration at a sampl...
INNOVA: response time for NH3        -> time delay
INNOVA 1412: verification for NH3 and CH4         -> time delay for NH3
INNOVA: time pattern of initial NH3 emission rate  (factor 2 difference in NH4 application rate)
Static flux chamber (INNOVA)               The Green DuoENH3 emission factor ~ 1%Underestimation (absence turbulent wind, ...
time (h)                                             <- CeqInitial NH3 emission rates should be ~ 50 times higherto achiev...
Conclusion V• After taking into account one published  underestimation of a factor 7 by using static  flux chambers still ...
Laboratory slurry 15N experiment: soil coreswith grass sward (Chadwick et al. 2001; 8 days)N balance       Surface-applied...
Grassland fertilisation experiment on two sandy grassland farms:Apparent Herbage Nitrogen Recovery                        ...
Conclusion VI• Surface application: much higher gaseous N  losses other than NH3 compared to injection• After field applic...
Three-dimensional characterizationof the ammonia plume from a beefcattle feedlot (17,220 head)Ralf M. Staebler et al. (Atm...
Vertical flux<----------------->
Conclusion VIIAlso above manured fields the greatest proportion ofthe emitted NH3 will escape in vertical directionHowever...
Dry NH3 deposition: average NH3 compensation point                as determined with biomonitors (method: Sommer, 1988)Rel...
NH3 compensation point :                                                      In the order of 10-15 microgram             ...
Mts. Duiven (west of Dwingelderveld): 600 dairy cows (no grazing)              35                                         ...
14                                                   The Netherlands 1990-20121210                                        ...
1990-1998: - 55% (but no effects on        atmospheric NH3 concentrations!)- 40%
Methods to estimate NH3 emission from surface-applied cattle slurry manure
Methods to estimate NH3 emission from surface-applied cattle slurry manure
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Methods to estimate NH3 emission from surface-applied cattle slurry manure

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Methods to estimate NH3 emission from surface-applied cattle slurry manure

  1. 1. Methods to estimate NH3 emission from field-applied cattle slurry I. Wind tunnels II. Micrometeorological methods III. Passive samplers IV. Flux chambers V. Apparent herbage N recovery Egbert Lantinga Ciska Nienhuis Contact: egbert.lantinga@wur.nl
  2. 2. Wind tunnels (Misselbrook et al. 2005)• the turbulence of the air drawn through a wind tunnel may be quite different from that in an ambient situation -> differences in resistance to NH3 emission at the manure surface• wind tunnels measure emission from a 2 m long plot of land, which in effect, might be considered to be the edge of a manure-applied field.• clean air entering the upwind edge -> less resistance to emissions -> increased NH3 emission
  3. 3. Field: Ferm et al. (2000) NH3 concentration at 20 cm height: ~ 1/10 * Ceq
  4. 4. Wind tunnel (2010)NH3 concentration at 20 cm height: ~ 1/500 * Ceq (~ 50 times lower!)
  5. 5. Sommer (2003)Overestimation wind tunnel: about a factor 2
  6. 6. Sintermann (2012)Wind tunnels * ½ ->
  7. 7. Conclusion IAmmonia fluxes measured in wind tunnels(forced inflow of clean air; very small emittingarea) are per definition higher than will takeplace in the open fieldRecommendation 1: field area around the tunnelshould also be manured -> more realistic NH3content of the inlet air -> lower NH3 emission:new field experiment
  8. 8. Effects of wind speed and radiation (Sommer 2003)
  9. 9. Effects of temperature and wind speed (adapted from Schjoerring et al. 1993) ammonia.prn, X , Y , Z Rank 22 Eqn 2147 z=EXPX(a,b)*EXPY(1,b) r^2=0.92349514 DF Adj r^2=0.8724919 FitStdErr=2.3195267 Fstat=48.284261 a=0.93530461 b=-6.9231236 NH3 emission microgr NH3-N / m2.s 20 17.5 20 15 17.5 12.5 15 10 12.5 7.5 10 5 7.5 2.5 5 0 4 2.5 3.5 0 3 5 2.5 5 2 7. 10 .5 1.5 WS (m/s) 12 15 1 .5 T (oC) 17
  10. 10. Conclusion II- No clear effects of wind speed on NH3emission in the open field: interaction withtemperature and incoming solar radiation[Various literature sources: at increasingturbulence intensity of the air not more thanabout a doubling of the NH3 emission]
  11. 11. Micrometeorological methods- Mass balance method- Integrated horizontal flux method (r is the fetch)As far as we know only two in-situ validations havebeen carried out:- from beakers with NH4+/HCO3- solution- from an artificial NH3 gas source
  12. 12. Schjoerring et al. (1992): comparsion of direct (from beakers) and indirect measurements (MBM)M Mass balance method: ~ 50 % lower established NH3 losses
  13. 13. Mobile Lidar SystemBerkhout et al. (2008)
  14. 14. Conclusion IIITwo evaluations of the MBM in the field with artificial NH3 sources (knownreleased amounts) revealed that there were great inconsistencies:- case 1: 50% underestimation (deposition?)- case 2: 50% overestimation (no possible explanation)Calculation procedure MBM:- assumption 1: horizontal transport of NH3 at the rate of the wind speed- assumption 2: calculated NH3 emission dependent on the fetch (e.g. no significant change in concentration profile central mast with distance -> when fetch * 2 -> ammonia emission * ½ )- assumption 3: no vertical NH3 emission along the fetch above the height of the central mast
  15. 15. Passive flux samplers (Winsum 2012): height 20 cmfetch 100 – 150 m (point 1 close to field border upwind)
  16. 16. Conclusion IV- Over distances of a few tenths of meters on average only a small increase in NH3 concentration at a sampling height of 20 cm from the border of the manured grassland field (measuring point 1)- MBM will therefore calculate relatively very low NH3 emissions between points 1 and 2- NH3 emission becomes insignificant after 2-6 hours
  17. 17. INNOVA: response time for NH3 -> time delay
  18. 18. INNOVA 1412: verification for NH3 and CH4 -> time delay for NH3
  19. 19. INNOVA: time pattern of initial NH3 emission rate (factor 2 difference in NH4 application rate)
  20. 20. Static flux chamber (INNOVA) The Green DuoENH3 emission factor ~ 1%Underestimation (absence turbulent wind, time delayINNOVA, gaseous interferences) : multiplication with 7Upscaling to aboveground application: multiplicationwith 3/2  NH3 emission factor still low (~ 10%)
  21. 21. time (h) <- CeqInitial NH3 emission rates should be ~ 50 times higherto achieve an emission factor of 74%: this is impossible !
  22. 22. Conclusion V• After taking into account one published underestimation of a factor 7 by using static flux chambers still yields a low NH3 emission factor in our experiments for aboveground applied cattle slurry (max. 10%)• Also here NH3 emission became insignificant after 6 hours
  23. 23. Laboratory slurry 15N experiment: soil coreswith grass sward (Chadwick et al. 2001; 8 days)N balance Surface-applied InjectedNH3 emission 15% 11%Grass 7% 2%Soil – inorg N 24% 55%Soil – org N 6% 8%Unaccounted for 48% 24%“Lost” N: emissions of N2, N2O and NOx(represented almost 50% of the applied inorganic N!)
  24. 24. Grassland fertilisation experiment on two sandy grassland farms:Apparent Herbage Nitrogen Recovery Conclusion: aboveground application of slurry manure in March –low temperatures- did not lead to significant gaseous N emissions Schils & Kok (2003)
  25. 25. Conclusion VI• Surface application: much higher gaseous N losses other than NH3 compared to injection• After field application in early spring (low temperatures) no difference in the fraction of N recovered in the harvested herbage between the two application methods -> very low NH3 emissions
  26. 26. Three-dimensional characterizationof the ammonia plume from a beefcattle feedlot (17,220 head)Ralf M. Staebler et al. (Atm. Environm., 2009)Conclusion: within a distance of 4 km from the farm more than 50% of the emitted NH3 has reached a vertical height of more than 135 m
  27. 27. Vertical flux<----------------->
  28. 28. Conclusion VIIAlso above manured fields the greatest proportion ofthe emitted NH3 will escape in vertical directionHowever, due to the very low emission levelscompared to livestock barns this is difficult to detectRecommendation 2: two field experiments toevaluate the MBM with (i) a row of at least threehigh sampling masts along the fetch and (ii) diffusivesamplers behind manured plots of diverging lengths
  29. 29. Dry NH3 deposition: average NH3 compensation point as determined with biomonitors (method: Sommer, 1988)Relationship between atmospheric ammonia concentration and total N yield ofunfertilized barley plants (spring-summer 2011: period of 80 days)
  30. 30. NH3 compensation point : In the order of 10-15 microgram per m3 Leith, Scotland (Deschampsia f.)0.12 3.5 0.1 30.08 2.50.06 20.04 1.50.02 1 0 1 10 100 0.5-0.02 0-0.04 0.1 1 10 100 Sommer, Denmark (Lolium m.)
  31. 31. Mts. Duiven (west of Dwingelderveld): 600 dairy cows (no grazing) 35 260 240 Conclusion: 30 220 OPS model has a number of shortcomings -> overestimation 200 25 of dry N deposition in “Natura 180 2000” areas 160 20 NH3 concentrations OPS-model included kg--1 ha-1 yr-1NH3 [µg m3] 140 with background concentration 120 Dry deposition NHx OPS-model included 15 with background deposition 100 Dry deposition NHx based on biomonitors 80 10 60 5 40 Recommendation 3: Continuation, also including 20 “Natura 2000” areas with mosses 0 0 0 200 400 600 800 1000 1200 1400 Distance to source (m) Dry deposition OPS model vs. measurements: - Underestimated around the livestock barns (< 300 m) - Overestimated away from the farm (> 400 m: undetectable )
  32. 32. 14 The Netherlands 1990-20121210 atmospheric NH3-conc - 25% 8 6 Manure-N - 30% 4 2 Overall: good correlation 0 1985 1990 1995 2000 2005 2010 2015 Conclusion: adaptations in manure application techniques and housing systems since 1990 have not contributed to the observed decrease in atmospheric NH3 concentrations ; only the decrease in the total amount of excreted N by the Dutch livestock sector played a role
  33. 33. 1990-1998: - 55% (but no effects on atmospheric NH3 concentrations!)- 40%

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