The NERC-funded study, led by the University of Bristol's Department of Civil Engineering, has looked at nitrate transport from agricultural land to water in the Thames basin. The team used a simple model to estimate the amount of nitrate able to leach from soils to the groundwater based on land use practices along with an algorithm that determined the route nitrate would take to reach surface or groundwater from agricultural areas.
The Thames River catchment provides a good study example because the water quality in the river, which supplies drinking water to millions of people, has been monitored for the past 140 years, and the region has undergone significant agricultural development over the past century.
The study found that nitrate concentrations in the Thames rose significantly during and after World War II to about double their previous level, then increased again in the early 1970s. Nitrite concentrations have remained at that high level even though nitrate from inputs from agriculture declined from the late 1970s to early 2000s.
The researchers observed it takes some time for nitrate to reach the river, and their analysis suggests that the jump in nitrate concentrations from 1968 to 1972 is due to the delayed groundwater response to ploughing of permanent grasslands during World War II.
Dr Nicholas Howden, Senior Lecturer in Water in the Department of Civil Engineering, who led the research, said: "Balancing the needs for agriculture and clean groundwater for drinking requires understanding factors such as the routes by which nitrate enters the water supply and how long it takes to get there.
"Our results suggest it could take several decades for any reduction in nitrate concentrations of river water and groundwater, following significant change in land management practices."
Co-author of the research paper, Dr Fred Worrall in the Department of Earth Sciences at Durham University, added: "The 60s and 70s saw a gradual intensification of food crop production and consequent nitrate release from the land. If your input is dispersed, your output is dispersed; if your input is sharp, your output is sharp. The aquifer is just transporting it; it's not processing it. The nitrate comes through as a pulse."
Co-author, Professor Tim Burt in the Department of Geography at Durham University, said: "You can work out the budget, and there is a phenomenal amount of nitrogen accumulating somewhere in the Thames basin. We don't know where and we don't know in what form, but it represents a potential legacy for a long time. The effects of land-use changes can take decades to filter through the river basin and this has major implications for policies to manage rivers."
The researchers found that any solution to the nitrate issue will require a long-term vision for water-quality remediation. In terms of sustainable groundwater, there seem to be no ''quick fixes'' and if groundwater nitrate concentrations continue to rise in the UK the worst may be yet to come.
The study could help water and land management planners identify practices that best preserve both agricultural production and water quality.
Paper: Nitrate pollution in intensively farmed regions: What are the prospects for sustaining high-quality groundwater?, Nicholas J K Howden, Tim P Burt, Fred Worrall, Simon Mathias, and Mick J Whelan, Water Resources Research, Vol 47, 12 November, 2011
Joanne Fryer | EurekAlert!
Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.
100 % Organic Farming in Bhutan – a Realistic Target?
15.06.2018 | Humboldt-Universität zu Berlin
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
22.06.2018 | Materials Sciences
22.06.2018 | Earth Sciences
22.06.2018 | Life Sciences