The ALFAM2 database on ammonia emission from field-applied manure: description and illustrative analysis

Authors: HAFNER, SASHA - University Of Southern Denmark; PACHOLSKI, ANDREAS - University Of Kiel; BITTMAN, SHABTAI - Agriculture And Agri-Food Canada; BURCHILL, WILLIAM - Teagasc (AGRICULTURE AND FOOD DEVELOPMENT AUTHORITY); BUSSINK, WIM - Wageningen Agricultural University; CHANTIGNY, MARTIN - Agriculture And Agri-Food Canada; CAROZZI, MARCO - University Of Milan; GENERMONT, SOPHIE - Agro Paris Tech; HANI, CHRISTOPH - Zurich University Of Applied Sciences; HANSEN, MARTIN - Danish Institute For Agricultural Science; HUIJSMANS, JAN - Wageningen University; HUNT, DEREK - Agriculture And Agri-Food Canada; KUPPER, THOMAS - Zurich University Of Applied Sciences; LANIGAN, GARY - Teagasc (AGRICULTURE AND FOOD DEVELOPMENT AUTHORITY); LOUBET, BENJAMIN - Agro Paris Tech; MISSELBROOK, THOMAS - Rothamsted Research; Meisinger, John; NEFTEL, ALBRECHT - Agroscope; NYORD, TAVS - Aarhus University; PEDERSEN, SIMON - University Of Southern Denmark; ROCHETTE, PHILIPPE - Agriculture And Agri-Food Canada; SINTERMANN, JORG - Agroscope; THOMPSON, RODNEY - University Of Almeria; VERMEULEN, G - Wageningen University; VESTERGAARD, ANNETTE - Danish Institute For Agricultural Science; VOYLOKOV, POLINA - Agro Paris Tech; WILLIAMS, JOHN - National Agrarian University - Ukraine; SOMMER, SVEN - University Of Southern Denmark

Submitted to: Agricultural and Forest Meteorology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/22/2017
Publication Date: 11/27/2017
Citation: Hafner, S.D., Pacholski, A.S., Bittman, S., Burchill, W., Bussink, W.D., Chantigny, M.H., Carozzi, M., Genermont, S., Hani, C., Hansen, M.N., Huijsmans, J.F., Hunt, D.E., Kupper, T., Lanigan, G.J., Loubet, B., Misselbrook, T.H., Meisinger, J.J., Neftel, A., Nyord, T., Pedersen, S.V., Rochette, P., Sintermann, J., Thompson, R.B., Vermeulen, G.D., Vestergaard, A., Voylokov, P., Williams, J.R., Sommer, S.G. 2017. The ALFAM2 database on ammonia emission from field-applied manure: description and illustrative analysis. Agricultural and Forest Meteorology. https://doi.org:10.1016/j.agrformet.2017.11.027.
DOI: https://doi.org/10.1016/j.agrformet.2017.11.027

Interpretive Summary: Ammonia volatilization is a major nitrogen loss process for surface-applied manures, commonly amounting to 10-30% of the manure total nitrogen. This nitrogen emission through volatilization, is not only an economic loss of an essential plant nutrient for farmers, but also contributes to air pollution and degradation of aquatic and natural ecosystems. Nitrogen losses through volatilization are quite variable and depend on several factors including manure characteristics (such as dry matter and pH), application method (such as band application or incorporation), environmental factors (including temperature and wind speed), and soil conditions (including residue cover and moisture content). Ammonia volatilization from manures has been measured in many studies in both Europe and North America over the past few decades. This research data has now been collected and organized into the ALFAM2 database. This paper describes the development of the database, summarizes the contents, and provides an initial description of the effects of application methods and other variables on ammonia emissions. It also discusses the challenges for data analysis and model development for the ALFAM2 database. The database contains measurements of ammonia emissions, manure and soil properties, weather, application technique, and other types of data for 1,866 plots from 12 countries and 22 research institutes. For example, the database contains ammonia emission data from eight manure types (including both liquid and solid manures from cattle, swine, and poultry), and four main crops (grass, cereal, maize, and stubble) including bare soil. Application methods include manure broadcast on the surface, localized banded applications on the soil surface, and injection into the soil. Cattle slurry applied to grassland was the most common combination and provided the data for this initial summary of the effects of application methods on ammonia losses. Analysis of this subset showed clear, although variable, emission reductions for banded surface-applications of approximately 50% compared to surface broadcast, and corresponding reductions of 70% or more for injection. There was also evidence of positive effects of air temperature and wind speed on emission, with ammonia losses increasing with warmer temperatures and higher wind speeds. However, the results also showed some substantial differences among research institutes between seemingly comparable treatments, which are thought to be due to differences in soils or other variables not included in the models, or biases in measurement methods. The ALFAM2 database should be useful for development and evaluation of both emission factors and emission models, but users need to recognize the limitations caused by some variables being unintentionally linked together, incomplete variable reporting, and correlation among observations from the same institute. Expansion of the ALFAM2 database will continue, and readers are invited to contact the corresponding author for more information on data submission. The continued development of the ALFAM2 database will not only preserve and provide access to existing emission data; it will also provide opportunities for improving the measurement of ammonia emissions, for identifying additional supporting data, and for describing standard protocols that are necessary in order to produce more accurate and robust ammonia-emission measurements.

Technical Abstract: Ammonia (NH3) emission from animal manure contributes to air pollution and ecosystem degradation, and is a loss of reactive nitrogen (N) from agricultural systems. Estimates of NH3 emission are necessary for national inventories and nutrient management. Many studies have made measurements of NH3 emission from field-applied manure over the past few decades, and in this work, we facilitate the use of these data by collecting and organizing measurements in a database: the ALFAM2 database. In this paper we describe the development and summarize the contents of the database, quantify effects of application methods and other variables on emission using a data subset, and discuss challenges for data analysis and model development. The database contains measurements of emission, manure and soil properties, weather, application technique, and other types of data for 1,866 plots from 12 countries and 22 research institutes. Data on eight manure types (cattle, pig, chemical concentrate, mink, poultry, sludge, mixed, and other) applied to four types of crops (grass, cereal, maize, stubble, and other) or bare soil are included. Application methods include broadcast, trailing hose (band application), trailing shoe, open slot injection, and other less common techniques. Cattle manure application to grassland was the most common combination. Analysis of this subset (and limited to slurry with dry matter < 15%) using fixed- and mixed-effects models showed clear, albeit variable, reductions due to trailing hose, trailing shoe, and open slot injection of slurry. There was evidence of positive effects of air temperature and wind speed on emission, and limited evidence of effects of manure dry matter concentration on ammonia emission. However, coefficients for differences among research institutes were among the largest model coefficients, and showed a deviation from the mean response by more than 100% in some cases. The source of these institute differences could not be determined, but there is some evidence that they are related to differences in soils or biases in measurement methods. The ALFAM2 database should be useful for development and evaluation of both emission factors and emission models, but users need to recognize the limitations caused by confounding variables, imbalance in the dataset, and correlation among observations from the same institute. International agreement on how ammonia emission should be measured, along with necessary types of supporting data and standard protocols for their measurement is needed in order to produce more accurate and useful ammonia emission measurements. Expansion of the ALFAM2 database will continue, and readers are invited to contact the corresponding author for more information on data submission.