A B S T R A C T Storage of slurry is an important emission source for ammonia (NH 3 ), nitrous oxide (N 2 O), methane (CH 4 ), carbon dioxide (CO 2 ) and hydrogen sulfide (H 2 S) from livestock production. Therefore, this study collected published emission data from stored cattle and pig slurry to determine baseline emission values and emission changes due to slurry treatment and coverage of stores. Emission data were collected from 120 papers yielding 711 records of measurements conducted at

more »

... rm-, pilot-and laboratory-scale. The emission data reported in a multitude of units were standardized and compiled in a database. Descriptive statistics of the data from untreated slurry stored uncovered revealed a large variability in emissions for all gases. To determine baseline emissions, average values based on a weighting of the emission data according to the season and the duration of the emission measurements were constructed using the data from farm-scale and pilot-scale studies. Baseline emissions for cattle and pig slurry stored uncovered were calculated. When possible, it was further distinguished between storage in tanks without slurry treatment and storage in lagoons which implies solid-liquid separation and biological treatment. The baseline emissions on an area or volume basis are: for NH 3 : 0.12 g m −2 h -1 and 0.15 g m −2 h -1 for cattle and pig slurry stored in lagoons, and 0.08 g m −2 h -1 and 0.24 g m −2 h -1 for cattle and pig slurry stored in tanks; for N 2 O: 0.0003 g m −2 h -1 for cattle slurry stored in lagoons, and 0.002 g m −2 h -1 for both slurry types stored in tanks; for CH 4 : 0.95 g m -3 h -1 and 3.5 g m -3 h -1 for cattle and pig slurry stored in lagoons, and 0.58 g m -3 h -1 and 0.68 g m -3 h -1 for cattle and pig slurry stored in tanks; for CO 2 : 6.6 g m −2 h -1 and 0.3 g m −2 h -1 for cattle and pig slurry stored in lagoons, and 8.0 g m −2 h -1 for both slurry types stored in tanks; for H 2 S: 0.04 g m −2 h -1 and 0.01 g m −2 h -1 for cattle and pig slurry stored in lagoons. Related to total ammoniacal nitrogen (TAN), baseline emissions for tanks are 16% and 15% of TAN for cattle and pig slurry, respectively. Emissions of N 2 O and CH 4 relative to nitrogen (N) and volatile solids (VS) are 0.13% of N and 0.10% of N and 2.9% of VS and 4.7% of VS for cattle and pig slurry, respectively. Total greenhouse gas emissions from slurry stores are dominated by CH 4 . The records on slurry treatment using acidification show a reduction of NH 3 and CH 4 emissions during storage while an increase occurs for N 2 O and a minor change for CO 2 as compared to untreated slurry. Solid-liquid separation causes higher losses for NH 3 and a reduction in CH 4 , N 2 O and CO 2 emissions. Anaerobically digested slurry shows higher emissions during storage for NH 3 while losses tend to be lower for CH 4 and little changes occur for N 2 O and CO 2 compared to untreated slurry. All cover types are found to be efficient for emission mitigation of NH 3 from stores. The N 2 O emissions increase in many cases due to coverage. Lower CH 4 emissions occur for impermeable covers as compared to uncovered slurry storage while for permeable covers the effect is unclear or emissions tend to increase. Limited and inconsistent data regarding emission changes with covering stores are available for CO 2 and H 2 S. The compiled data provide a basis for improving emission inventories and highlight the need for further research to reduce uncertainty and fill data gaps regarding emissions from slurry storage.