Projects per year
Abstract
Diffuse water pollution from agriculture (DWPA) is a major environmental concern, with significant adverse impacts on both human and ecosystem health. However, without an appropriate understanding of the multiple factors impacting on water, mitigation measures cannot be targeted. Therefore, this paper addresses this gap in understanding, reporting the hydrochemical monitoring evidence collected from the UK Government's Demonstration Test Catchments (DTC) programme including contrasting chalk and clay/mudstone catchments. We use data collected at daily and sub-daily frequency over multiple sites to address: (1) How does the behaviour of the full range of nitrogen (N) species and phosphorus (P) fractions vary? (2) How do N species and P fractions vary inter- and intra-annually? (3) What do these data indicate about the primary pollution sources? And (4) which diffuse pollution mitigation measures are appropriate in our study landscapes?
Key differences in the rates of flux of nutrients were identified, dependent on catchment characteristics. Full N speciation and P fractionation, together with dissolved organic carbon (DOC) enabled identification of the most likely contributing sources in each catchment. Nitrate (NO3-N) was the dominant N fraction in the chalk whereas organic and particulate N comprised the majority of the load in the clay/mudstone catchments. Despite current legislation, orthophosphate (PO4-P) was not found to be the dominant form of P in any of the catchments monitored. The chalk sub-catchments had the largest proportion of inorganic/dissolved organic P (DOP), accompanied by episodic delivery of particulate P (PP). Contrastingly, the clay/mudstone sub-catchments loads were dominated by PP and DOP. Thus, our results show that by monitoring both the inorganic and organic fractions a more complete picture of catchment nutrient fluxes can be determined, and sources of pollution pin-pointed. Ultimately, policy and management to bring nutrient impacts under control will only be successful if a multi-stressor approach is adopted.
Key differences in the rates of flux of nutrients were identified, dependent on catchment characteristics. Full N speciation and P fractionation, together with dissolved organic carbon (DOC) enabled identification of the most likely contributing sources in each catchment. Nitrate (NO3-N) was the dominant N fraction in the chalk whereas organic and particulate N comprised the majority of the load in the clay/mudstone catchments. Despite current legislation, orthophosphate (PO4-P) was not found to be the dominant form of P in any of the catchments monitored. The chalk sub-catchments had the largest proportion of inorganic/dissolved organic P (DOP), accompanied by episodic delivery of particulate P (PP). Contrastingly, the clay/mudstone sub-catchments loads were dominated by PP and DOP. Thus, our results show that by monitoring both the inorganic and organic fractions a more complete picture of catchment nutrient fluxes can be determined, and sources of pollution pin-pointed. Ultimately, policy and management to bring nutrient impacts under control will only be successful if a multi-stressor approach is adopted.
Original language | English |
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Pages (from-to) | 1179-1200 |
Number of pages | 22 |
Journal | Science of The Total Environment |
Volume | 648 |
Early online date | 23 Aug 2018 |
DOIs | |
Publication status | Published - 15 Jan 2019 |
Keywords
- Nitrogen
- Phosphorus
- Headwater Catchments
- Catchment Characteristics
- Mitigation Measures
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Dive into the research topics of 'Determining the sources of nutrient flux to water in headwater catchments: Examining the speciation balance to inform the targeting of mitigation measures'. Together they form a unique fingerprint.Projects
- 2 Finished
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Demonstration Test Catchments - Phase 2: Demonstration Test Catchment - Phase 2
1/04/15 → 31/03/19
Project: Research
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DOMAINE: Characterisation of the nature, origins and ecological significance of dissolved organic matter in freshwater ecosystems
Johnes, P. J., Evershed, R. P., Jones, D., Maberly, S., Jickells, T., Yates, C. A., Lloyd, C. E. M., Glanville, H., Mackay, E., Harrison, R. V., Bayliss, C. E., Pemberton, J., Reay, M. K. M., Brailsford, F., McIntyre, C. A., Owen, A. T., Hopes, M., Evans, C., Fenner, N., Golyshin, P., Ferrer, M., Marshall, M. & Cooper, D.
1/04/14 → 31/12/19
Project: Research
Profiles
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Professor Penny J Johnes
- Hydrology - Professor of Biogeochemistry
- School of Geographical Sciences - Professor of Biogeochemistry
- Cabot Institute for the Environment
Person: Academic