Ammonia and nitrous oxide emission factors for excreta deposited by livestock and land-applied manure

Authors: VANDERWEERDEN, TONY - Agresearch; NOBLE, ALASDAIR - Agresearch; DE KLEIN, CECILE - Agresearch; HUTCHINGS, NICHOLAS - Aarhus University; THORMAN, RACHEL - Adas; ALFARO, MARTA - Inia Remehue - Osorno; AMON, BARBARA - Leibniz Institute; BELTRAN, IGNACIO - Inia Remehue - Osorno; GRACE, PETER - Queensland University Of Technology; HASSOUNA, MELYNDA - Inrae; KROL, DOMINIKA - Teagasc (AGRICULTURE AND FOOD DEVELOPMENT AUTHORITY); Leytem, April; SALAZAR, FRANCISCO - Inia Remehue - Osorno; VELTHOF, GERARD - Wageningen University And Research Center

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2021
Publication Date: 7/29/2021
Citation: Vanderweerden, T., Noble, A., De Klein, C.A., Hutchings, N., Thorman, R.E., Alfaro, M.A., Amon, B., Beltran, I., Grace, P., Hassouna, M., Krol, D.J., Leytem, A.B., Salazar, F., Velthof, G.L. 2021. Ammonia and nitrous oxide emission factors for excreta deposited by livestock and land-applied manure. Journal of Environmental Quality. 50:1005-1023. https://doi.org/10.1002/jeq2.20259.
DOI: https://doi.org/10.1002/jeq2.20259

Interpretive Summary: Utilizing the DATAMAN database, we have developed disaggregated ammonia emission factors (NH3 EFs)for cattle and swine manures applied to land in wet climates and nitrous oxide emission factors (N2O EF) for cattle, sheep and swine manure emissions in wet and dry climates. Given the underlying data were collated from multiple studies across several countries, these disaggregated EF values are at a scale greater than country-specific EF values. The NH3 EFs for broadcast cattle solid manure and slurry were 0.03 and 0.24 kg NH3-N per kg total N (TN), respectively, while broadcast swine slurry was 0.29. Emissions from both cattle and swine slurry were reduced between 46 and 62% with low emissions application methods. Land application of cattle and swine manure in wet climates had EFs of 0.005 and 0.011 kg N2O-N per kg TN, respectively, while in dry climates the EF for cattle manure was 0.0031. The N2O EF for cattle urine and dung in wet climates was 0.0095 and 0.002 kg N2O-N per kg TN, respectively, which were three times greater than for dry climates. The N2O EFs for sheep urine and dung in wet climates were 0.0043 and 0.0005, respectively. The use of nitrification inhibitors reduced N2O emissions in swine manure, cattle urine/dung and sheep urine by 45 to 63%. These improved and disaggregated EF values can be used by inventory compilers to improve the accuracy of national inventories and quantify the effectiveness of mitigation strategies where country-specific EFs do not exist. However, there are gaps within the current database, with some regions poorly represented (e.g. Asia, Africa, South America). We hope that, in time, data will become more representative as we continue to include additional studies within the DATAMAN database from a wide range of agricultural systems that are practiced under a range of climates and regions.

Technical Abstract: Manure application to land and deposition of urine and dung by grazing animals are major sources of ammonia (NH3) and nitrous oxide (N2O) emissions. Utilizing data on NH3 and N2O emissions following land-applied manures and excreta deposited during grazing, emission factors (EFs) disaggregated by climate zone were developed and effects of mitigation strategies evaluated. The NH3 data represents emissions from cattle and swine manures in temperate wet climates, while the N2O data includes cattle, sheep and swine manure emissions in temperate wet/dry and tropical wet/dry climates. The NH3 EFs for broadcast cattle solid manure and slurry were 0.03 and 0.24 kg NH3-N kg-1 total N (TN), respectively, while broadcast swine slurry was 0.29. Emissions from both cattle and swine slurry were reduced between 46 and 62% with low emissions application methods. Land application of cattle and swine manure in wet climates had EFs of 0.005 and 0.011 kg N2O-N kg-1 TN, respectively, while in dry climates the EF for cattle manure was 0.0031. The N2O EF for cattle urine and dung in wet climates was 0.0095 and 0.002 kg N2O-N kg-1 TN, respectively, which were three times greater than for dry climates. The N2O EFs for sheep urine and dung in wet climates were 0.0043 and 0.0005, respectively. The use of nitrification inhibitors reduced emissions in swine manure, cattle urine/dung and sheep urine by 45 to 63%. These enhanced EFs can improve national inventories; however, more data is needed across multiple livestock species and climates.