The group from China Agricultural University (China), Stanford University (USA), VU University Amsterdam and Louis Bolk Institute (Netherlands), Rothamsted Research and Agri-Food and Biosciences Institute (UK), and Hohenheim University have (GER) also note that increased nitrogen deposition is linked human activity, for example through agricultural, industrial and traffic sources.
Nitrogen is a vital nutrient for plants, but it can also be a key environmental pollutant causing ecosystem instability through providing excess nutrients to the land and sea, a process called eutrophication. This can lead to the acidification of soil and water, algal blooms, negative impacts on human health and increased emissions of atmospheric nitrous oxide which has a global-warming potential 300 times greater than carbon dioxide.
The meta-analysis shows that bulk N deposition increased significantly from 1980 to 2010 and was approximately 8 kg N per hectare or 60 per cent higher in the 2000s than in the 1980s, and was particularly pronounced in northern, southeast and southwest China. These N deposition levels in central China are much higher than those observed in any region of the US, and are comparable to the maximum values observed in the UK and the Netherlands when N deposition was at its peak in the 1980s.
Co-author Professor Keith Goulding from Rothamsted Research, which receives strategic funding for the BBSRC, said: “This important paper is the latest step in our long-standing collaboration with colleagues at China Agricultural University and around the world. Over the last 10 years we have identified serious issues with nitrogen pollution and sought to develop solutions. China is aware and concerned but has a major challenge in maintaining economic growth while reducing environmental pollution. We look forward to continued world-leading research such as reported here to resolve this problem to the benefit of China and the global community.”
Further analysis of this data attempts to highlight the relative influences of agricultural sources versus non-agricultural sources and the authors conclude that environmental policy in China needs to focus more strongly on reducing nitrogen emissions from agricultural sources (especially fertilisers and livestock), while control nitrogen gas emissions from industrial and traffic sources will become more important in the near future.
