Peer-reviewed publications are listed below chronologically, with the most recent papers at the top. Click on [download] for a copy of any paper. For reports, conference papers, or other publications not listed here, send me a request through the contact page.

59. Hafner, S.D., Astals, S., Holliger, C., Koch, K., Nielsen, L., Refsahl, L., Weinrich, S., 2022. Assessing the value of kinetic results from biochemical methane potential tests: Reproducibility from a large inter-laboratory study. Cleaner Chemical Engineering 4, 100065. [download]

58. Pedersen, J., Hafner, S.D., Adamsen, A.P.S., 2022. Effectiveness of mechanical separation for reducing ammonia loss from field-applied slurry: Assessment through literature review and model calculations. Journal of Environmental Management 323, 116196. [download]

57. Sommer, S.G., Hafner, S.D., Laubach, J., van der Weerden, T.J., Leytem, A.B., Pacholski, A. 2022. Model for calculating ammonia emission from stored animal liquid manure. Biosystems Engineering. [download]

56. Wagner, C., Nyord, T., Vestergaard, A., Hafner, S. D., Pacholski, A. 2021. Acidification Effects on In Situ Ammonia Emissions and Cereal Yields Depending on Slurry Type and Application Method. Agriculture 2021, 11, 1053. [download]

55. Mortensen, J., Møller, M., Ward, A., Weisbjerg, M., Hafner, S.D., Møller, H.B. 2021. Determination of nitrogen and sulphur mineralization in batch and semi-continuous anaerobic digestion using an artificial fiber bag technique. Energies 2021, 14, 4205. [download]

54. Dalby, F.R.; Hafner, S.D.; Petersen, S.O.; Vanderzaag, A.; Habtewold, J.; Dunfield, K.; Chantigny, M.H.; Sommer, S.G. A Mechanistic Model of Methane Emission from Animal Slurry with a Focus on Microbial Groups. PLOS ONE 2021, 16, e0252881, doi:10.1371/journal.pone.0252881 [download]

53. Dalby, F.R.; Hafner, S.D.; Petersen, S.O.; VanderZaag, A.C.; Habtewold, J.; Dunfield, K.; Chantigny, M.; Sommer, S.G. Understanding Methane Emission from Stored Animal Manure: A Review to Guide Model Development. Journal of Environmental Quality 2021, doi:10.1002/jeq2.20252 [download]

52. Pedersen, J., Andersson, K., Feilberg, A., Delin, S., Hafner, S., Nyord, T. 2021. Effect of exposed surface area on ammonia emissions from untreated, separated, and digested cattle manure. Biosystems Engineering 202, 66–78. [download]

51. Holliger, C., Astals, S., de Laclos, H.F., Hafner, S.D., Koch, K., Weinrich, S., 2020. Towards a standardization of biomethane potential tests: a commentary. Water Science and Technology 83, 247–250. [download]

50. Beltran, I., Weerden, T.J. van der, Alfaro, M.A., Amon, B., Klein, C.A.M. de, Grace, P., Hafner, S., Hassouna, M., Hutchings, N., Krol, D.J., Leytem, A.B., Noble, A., Salazar, F., Thorman, R.E., Velthof, G.L., 2020. DATAMAN: A global database of nitrous oxide and ammonia emission factors for excreta deposited by livestock and land-applied manure. Journal of Environmental Quality n/a. [download]

49. Hafner, S.D., Fruteau de Laclos, H., Koch, K., Holliger, C., 2020. Improving Inter-Laboratory Reproducibility in Measurement of Biochemical Methane Potential (BMP). Water 12, 1752. [download]

48. Amodeo, C., Hafner, S.D., Teixeira Franco, R., Benbelkacem, H., Moretti, P., Bayard, R., Buffière, P., 2020. How Different Are Manometric, Gravimetric, and Automated Volumetric BMP Results? Water 12, 1839. [download]

47. Astals, S., Koch, K., Weinrich, S., Hafner, S.D., Tait, S., Peces, M., 2020. Impact of Storage Conditions on the Methanogenic Activity of Anaerobic Digestion Inocula. Water 12, 1321. [download]

46. Koch, K., Hafner, S.D., Astals, S., Weinrich, S., 2020. Evaluation of Common Supermarket Products as Positive Controls in Biochemical Methane Potential (BMP) Tests. Water 12, 1223. [download]

45. Pedersen, J.M., Feilberg, A., Kamp, J.N., Hafner, S., Nyord, T., 2020. Ammonia emission measurement with an online wind tunnel system for evaluation of manure application techniques. Atmospheric Environment 230, 117562. [download]

44. Koch, K., Hafner, S.D., Weinrich, S., Astals, S., Holliger, C., 2020. Power and Limitations of Biochemical Methane Potential (BMP) Tests. Front. Energy Res. 8. [download]

43. Justesen, C., Astals, S*., Mortensen, J.R., Thorsen, R., Koch, K., Weinrich, S., Triolo, J.M., Hafner, S.D.* 2019. Development and validation of a low-cost gas density method for measuring biochemical methane potential (BMP). Water 11 (12): 2431. [download]

42. Koch, K., Hafner, S.D., Weinrich, S., Astals, S. 2019. Identification of critical problems in BMP tests from methane production curves. Frontiers in Environmental Science 7: 178. [download]

41. Vilms Pedersen, S., Marti-Herrero, J., Singh, A.K., Sommer, S.G., Hafner, S.D. 2019. Management and design of biogas digesters: A non-calibrated heat transfer model. Bioresource Technology 296: 122264. [download]

40. Hafner, S.D.*, Astals, S. 2019. Systematic error in manometric measurement of biochemical methane potential: Sources and solutions. Waste Management 91: 147-155. doi: 10.1016/j.wasman.2019.05.001 [download]

39. Hafner, S.D.*, Pacholski, A., Bittman, S., Carozzi, M., Chantigny, M., Génermont, S., Häni, C., Hansen, M.N., Huijsmans, J., Kupper, T., Misselbrook, T., Neftel, A., Nyord, T., Sommer, S.G. 2019. A flexible semi-empirical model for estimating ammonia volatilization from field-applied slurry. Atmospheric Environment 199: 474-184. doi: 10.1016/j.atmosenv.2018.11.034 [download ]

38. Hafner, S.D., Koch, K., Carrere, H., Astals, S., Weinrich, S., Rennuit, C. 2018. Software for biogas research: Tools for measurement and prediction of methane production. SoftwareX 7, 205–210. doi: 10.1016/j.softx.2018.06.005 [download]

37. Pedersen, S.V., Scotto di Perta, E., Hafner. S.D., Pacholski, A.S., Sommer, S.G. 2017. Evaluation of a simple, small-plot meteorological technique for measurement of ammonia emission – feasibility, costs and recommendations. Transactions of the ASABE. doi: 10.13031/trans.12445 [download]

36. Hafner, S.D., Rennuit, C., Olsen, P.J., Pedersen, J.M. 2018. Quantification of leakage in batch biogas assays. Water Practice and Technology. doi: 10.2166/wpt.2017.111 [download]

35. Hafner, S.D., Madsen, J.T., Pedersen, J.M., Rennuit, C. 2018. Inter-stage thermophilic aerobic digestion may increase organic matter removal from wastewater sludge without decreasing biogas production. Water Science and Technology. doi: 10.2166/wst.2017.590 [download]

34. Hafner, S.D., Pacholski, A., Bittman, S., Burchill, W., Bussink, W., Chantigny, M., Carozzi, M., Génermont, S., Häni, C., Hansen, M.N., Huijsmans, J., Hunt, D., Kupper, T., Lanigan, G., Loubet, B., Misselbrook, T., Meisinger, J.J., Neftel, A., Nyord, T., Pedersen, S.V., Sintermann, J., Thompson, R.B., Vermeulen, B., Vestergaard, A.V., Voylokov, P., Williams, J.R., Sommer, S.G., 2018. The ALFAM2 database on ammonia emission from field-applied manure: Description and illustrative analysis. Agricultural and Forest Meteorology. doi: 10.1016/j.agrformet.2017.11.027 [download]

33. Rennuit, C., Triolo J. M., Eriksen, S., Jiminez, J., Carrere, H., Hafner, S.D. 2018. Comparison of pre- and inter-stage aerobic treatment of wastewater sludge: effects on biogas production and COD removal. Bioresource Technology. doi:10.1016/j.biortech.2017.08.128 [download]

32. Sommer, S.G., Clough, T.J., Blaine, N., Hafner, S.D., Cameron, K.C. 2017. Transformation of organic matter and the emissions of methane and ammonia during storage of liquid manure as affected by acidification. Journal of Environmental Quality 46: 514-521. doi: 10.2134/jeq2016.10.0409. [download]

31. Bonifacio, H.F., Rotz, C.A., Hafner, S.D., Montes, F., Cohen, M., Mitloehner, F.M. 2017. A process-based emission model of volatile organic compounds from silage sources on farms. Atmospheric Environment 152: 85-97. [download]

30. Hafner, S.D., Sommer, S.G., Petersen, V., Markfoged, R. 2017. Effects of carbon dioxide hydration kinetics and evaporative convection on pH profile development during interfacial mass transfer of ammonia and carbon dioxide. Heat and Mass Transfer. doi:10.1007/s00231-016-1910-6 [download]

29. Katz, J., Hafner, S.D., Donovan, T. 2016. Tools for automated acoustic monitoring within the R package monitoR. Bioacoustics 25: 197-210. [download]

28. Katz, J., Hafner, S.D., Donovan, T. 2016. Assessment of Error Rates in Acoustic Monitoring with the R package monitoR. Bioacoustics 25: 177-196. [download]

27. Petersen, S.O., Hutchings, N.J., Hafner, S.D., Sommer, S.G., Hjorth, M., Jonassen, K.E.N. 2016. Ammonia abatement by slurry acidification: a pilot-scale study of three finishing pig production periods. Agriculture, Ecosystems & Environment 216: 258–68. doi:10.1016/j.agee.2015.09.042. [download]

26. Hafner, S.D., Rennuit, C., Triolo, J.M, Richards, B.K. 2015. Validation of a simple gravimetric method for measuring biogas production in laboratory experiments. Biomass and Bioenergy 83: 297-301 [download]

25. Hafner, S.D., Windle, M., Merrill, C., Smith, M.L., Franco, R.B., Kung, L. 2015. Effects of potassium sorbate and Lactobacillus plantarum MTD1 on production of ethanol and other volatile organic compounds in corn silage. Animal Feed Science and Technology 208: 79-85. [download]

24. Petersen, V., Markfoged, R., Hafner, S.D., Sommer, S.G. 2014. A new slurry pH model accounting for effects of ammonia and carbon dioxide volatilization on solution speciation. Nutrient Cycling in Agroecosystems 100: 189-204 [download]

23. Hafner, S.D., Franco, R.B., Kung, L.K., Jr., Rotz, C.A., Mitloehner, F.M. 2014. Potassium sorbate reduces production of ethanol and two esters in corn silage. Journal of Dairy Science 97: 7870-7878. [download]

22. Waldrip, H. M., Rotz, C. A., Hafner, S.D., Todd, R. W., Cole, N. A.. 2014. Process-based modeling of ammonia emission from beef cattle feedyards with the Integrated Farm Systems Model. Journal of Environmental Quality 43(4): 1159-11168. [download]

21. Rotz, C.A., Montes, F., Hafner, S.D., Heber, A.J., Grant, R.H. 2014. Ammonia emission model for whole farm evaluation of dairy production systems. Journal of Environmental Quality doi:10.2134/jeq2013.04.0121 [download]

20. Hafner, S.D., Howard, C., Muck, R.E., Franco, R. B., Montes, F., Green, P. G., Mitloehner, F., Trabue, S. L., Rotz, C. A. 2013. Emission of volatile organic compounds from silage: compounds, sources, and implications. Atmospheric Environment 77: 827-839 [download]

19. Hafner, S.D., Montes, F., Rotz, C.A. 2012. A mass transfer model for VOC emission from silage. Atmospheric Environment 54: 134-140 [download]

18. Hafner, S.D., Meisinger, J., Mulbry, W., Ingram, S. 2012. A pH-based method for measuring gaseous ammonia. Nutrient Cycling in Agroecosystems 92: 195-205 [download]

17. Hafner, S.D., Montes, F., Rotz, C.A. 2012. Role of carbon dioxide in emission of ammonia from manure. Atmospheric Environment. 66: 63-71 [download]

16. Quaye, A.K., Volk, T.A., Hafner, S.D., Leopold, D. J., Schirmer, C. 2011. Impacts of paper sludge and manure on soil and biomass production of willow. Biomass and Bioenergy 35: 2796-2806. [download]

15. Hafner, S.D., Montes, F., Rotz, C.A., Mitloehner, F. 2010. Ethanol emission from loose corn silage and exposed silage particles. Atmospheric Environment 44: 4172-4180. [download]

14. El-Mashad H.M., Zhang, R., Rumsey, T., Hafner, S.D., Montes, F., Rotz, C.A., Arteaga, V., Zhao, Y., Mitloehner, F.M. 2010. A mass transfer model of ethanol emission from thin layers of corn silage. Transactions of the ASABE 53: 1903-1909. [download]

13. Montes, F., Hafner, S.D., Rotz, C.A., Mitloehner, F. 2010. Temperature and air velocity effects on ethanol emission from corn silage with the characteristics of the exposed face of a bunker silo. Atmospheric Environment 44: 1987-1995. [download]

12. Farrell, J., Murray, B., Leopold, D., Halpern, A., Rippke, M., Godwin, K., Hafner, S.D. 2009. Water-level regulation and coastal wetland vegetation in the upper St. Lawrence River: inferences from historical aerial imagery, seed banks, and Typha dynamics. Hydrobiologia 647: 127-144. [download]

11. Hafner, S.D., Bisogni, J.J. Jr. 2009. Modeling of ammonia speciation in anaerobic digesters. Water Research 43: 4105-4114. [download]

10. Hafner, S.D. 2007. Biological hydrogen production from nitrogen-deficient substrates. Biotechnology and Bioengineering 97: 435-437. [download]

9. Hafner, S.D., Bisogni, J.J. Jr. 2007. A simple method for measurement of inorganic carbon concentration and carbonate system alkalinity in anaerobic digesters. Agricultural Engineering International: The CIGR Ejournal IX. [download]

8. Hafner, S.D., Bisogni, J.J. Jr., Jewell, W.J. 2006. Measurement of un-ionized ammonia in complex mixtures. Environmental Science and Technology 40: 1597-1602. [download]

7. Hafner, S.D., Jewell, W.J. 2006. Predicting nitrogen and phosphorus removal in wetlands due to detritus accumulation: a simple mechanistic model. Ecological Engineering 27: 13-21. [download]

6. Forrester, J.A., Leopold, D.J., Hafner, S.D. 2005. Maintaining critical habitat in a heavily managed landscape: effects of power line corridor management on Karner blue butterfly (Lycaeides Melissa samuelis) habitat. Restoration Ecology 13(3): 488-498. [download]

5. Hafner, S.D., Groffman, P.M. 2005. Soil nitrogen cycling under litter and coarse woody debris in a mixed forest in New York State. Soil Biology and Biochemistry 37: 2159-2162. [download]

4. Hafner, S.D., Groffman, P.M., Mitchell, M.J. 2005. Leaching of dissolved organic carbon, dissolved organic nitrogen, and other solutes from coarse woody debris and litter in a mixed forest in New York State. Biogeochemistry 74: 257-282. [download]

3. Hafner, S.D. 2003. Brief communication: Is fertilizer efficiency misleading? Nature 422: 397-398. [download]

2. Hafner, S.D. 2003. Trends in maize, rice, and wheat yields for 188 nations over the past 40 years: a prevalence of linear growth. Agriculture, Ecosystems, and Environment 97: 275-283. [download]

1. Godwin, K.S., Hafner, S.D., Buff, M.F. 2003. Long-term trends in sodium and chloride in the Mohawk River, New York: the effect of fifty years of road salt application. Environmental Pollution 124: 273-281. [download]