Analysis of the EMEP 2013 Emission factors for mineral fertilizers Sebastian Wulf TFEIP – Agriculture and Nature Panel 13th May 2014, Ghent

Comparison of EMEP 2013 vs EMEP 2009 EMEP 2013EMEP 2009 (9°C)Difference kg NH 3 /kgN % Calcium ammonium nitrate (CAN) 0,0220, Ammonium nitrate (AN) 0,0370, Ammonium sulphate (AS) 0,013(*)0,016(*)-19 Ammonium phosphate (MAP/DAP) 0,113(*)0,016(*)+606 Urea AN0,1250, Urea0,2430, (*) for soils with pH < 7 Strong increase in calculated emissions from mineral fertizers in inventories 1 Data for analysis of the emission factors was readily provided by the colleagues of Aarhus University

Calcium ammonium nitrate – CAN Negative values excluded Negative values =0 All values %Nkg NH 3 /kgN%Nkg NH 3 /kgN%Nkg NH 3 /kgN Wind tunnel3,161,51-0,40 Ventilated chambers0,470,43 all1,820,0221,140,014-0,12 2 CAN NH 3 -N-losses [% of N] Temperature [°C]

Ammonium nitrate - AN Negative values excluded Negative values =0 All values %Nkg NH 3 /kgN%Nkg NH 3 /kgN%Nkg NH 3 /kgN Wind tunnel3,030,0372,440,0301,99 0,024 3 AN NH 3 -N-losses [% of N] Temperature [°C]

CAN and AN [kg NH 3 /kg N]EMEP 2013EMEP 2009 (9°C) Ammonium nitrate0,0370,009 Calcium ammonium nitrate0,0220,009 Based on chemical composition of the fertilizers EF of CAN should be greater or similar to AN [% von N] Negative values excluded Negative values =0 all values %Nkg NH 3 /kgN%Nkg NH 3 /kgN%Nkg NH 3 /kgN Ammoniumnitrat3,3 0,040 2,1 0,026 1,1 0,013 Kalkammonsalpeter3,50,0431,90,0231,10,013 Chadwick et al. (2005): Only study with direct comparison of AN und CAN (n=11) No differentiation between CAN and AN possible Chadwick et al. (2005) use all values and pooled AN and CAN data for the calculation of an emission factor 4 EF AN > CAN needs to be well justified

Analysis of pooled CAN and AN data Negative values excluded Negative values =0 all values %Nkg NH 3 /kgN%Nkg NH 3 /kgN%Nkg NH 3 /kgN Wind tunnel3,072,081,06 0,013 Ventilated chambers0,800,740,73 alle2,540,0311,840,0221,000,012 Much lower EF für AN as in EMEP 2013 If all values are considered, also for CAN lower than in EMEP CAN and AN ? Is it justified to neglect negative measurements (only)?

Ammonium phosphate (MAP, DAP) 7-fold increase of emission factor (pH low) [kg NH 3 /kg N]EMEP 2013EMEP 2009 (9°C) pH lowpH high Ammonium phosphate0,1130,2930,016 Data basis not sufficient NH 3 -N-losses [% of N] pH-value Lab experiment, not suitable for calculation of EF 6

Apart from 3 measurements all data considered are from soils pH >7 NH 3 -N-losses [% of N] pH-value Urea-AN Also not considered: 2 measurements on sandy soils (2,5%N, 1,5%N-losses), because pH not known Closed chambers (not considered) Measurements with closed chambers and measurements on sandy soils (pH < 7 assumed) indicate lower EF for soils with pH < 7. 7 Ammoniumsolutions – Urea AN [kg NH 3 /kg N]EMEP 2013EMEP 2009 (9°C) Urea AN0,1250,071

Urea [kg NH 3 /kg N]EMEP 2013EMEP 2009 (9°C) Urea0,2430,138 No temperature – or pH-dependency visible 8 Variablity and unknown conditions of measurement might superimpose these effects NH 3 -N-losses [% of N] Urea Temperature [°C]

Conclusion  Great advantage of EF in EMEP 2013 compared with EMEP 2009 is well compiled and documented data basis - some aspects of data analysis not clear from guidebook and need to be discussed (exclusion of negative values) 9  One common emission factor for CAN and AN should be calculated from pooled data as fundamental differences in emissions cannot be prooved.  Availability of data on emissions of ammonia phosphate (and ammonia sulphate) is very low. EF calculated from this basis are highly uncertain.  For Urea AN and Urea a pH and temperature dependency cannot be shown from the data set used – although most probably existing. -Effects of experimental conditions (time of application, precipitation etc) might superimpose effects of pH and temperature Well documented experiments are necessary to clearly identify parameters correlated with the hight of emissions – and to quantify their effects.