title: Simulation of nitrous oxide emissions at field scale using the SPACSYS model.
abstract: Nitrous oxide emitted to the atmosphere via the soil processes of nitrification and denitrification plays an important role in the greenhouse gas balance of the atmosphere and is involved in the destruction of stratospheric ozone. These processes are controlled by biological, physical and chemical factors such as growth and activity of microbes, nitrogen availability, soil temperature and water availability. A comprehensive understanding of these processes embodied in an appropriate model can help develop agricultural mitigation strategies to reduce greenhouse gas emissions, and help with estimating emissions at landscape and regional scales. A detailed module to describe the denitrification and nitrification processes and nitrogenous gas emissions was incorporated into the SPACSYS model to replace an earlier module that used a simplified first-order equation to estimate denitrification and was unable to distinguish the emissions of individual nitrogenous gases. A dataset derived from a Scottish grassland experiment in silage production was used to validate soil moisture in the top 10 cm soil, cut biomass, nitrogen offtake and N2O emissions. The comparison between the simulated and observed data suggested that the new module can provide a good representation of these processes and improve prediction of N2O emissions. The model provides an opportunity to estimate gaseous N emissions under a wide range of management scenarios in agriculture, and synthesises our understanding of the interaction and regulation of the processes.
authors.affiliation: Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton EX20 2SB, UK. Electronic address: Lianhai.Wu@rothamsted.ac.uk.
authors.forename: L
authors.initials: L
authors.lastname: Wu
authors.affiliation: Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK.
authors.forename: R M
authors.initials: RM
authors.lastname: Rees
authors.affiliation: Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK.
authors.forename: D
authors.initials: D
authors.lastname: Tarsitano
authors.affiliation: Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton EX20 2SB, UK; Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xubo
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Scotland's Rural College (SRUC), West Mains Road, Edinburgh EH9 3JG, UK.
authors.forename: S K
authors.initials: SK
authors.lastname: Jones
authors.affiliation: Sustainable Soils Grassland Systems Department, Rothamsted Research, Harpenden AL5 2JQ, UK.
authors.forename: A P
authors.initials: AP
authors.lastname: Whitmore
mesh_terms: D000383:Agriculture; D000397:Air Pollution / Q000032:analysis / Q000706:statistics & numerical data*; D001272:Atmosphere / Q000737:chemistry; D058440:Denitrification; D005308:Fertilizers; D008956:Models, Chemical; D058465:Nitrification; D009584:Nitrogen / Q000032:analysis; D009609:Nitrous Oxide / Q000032:analysis*; D012987:Soil
chemical_list: D005308:Fertilizers; D012987:Soil; D009609:Nitrous Oxide; D009584:Nitrogen
keywords: Denitrification; Grassland; Nitrogen cycling; Nitrous oxide; SPACSYS; Simulation model