Nav: Home

Adaptive management of soil conservation is essential to improving water quality

January 13, 2017

The quality of our rivers and lakes could be placed under pressure from harmful levels of soluble phosphorus, despite well-intended measures to reduce soil erosion and better manage and conserve farmland for crop production, a new study shows.

The UK-based Centre for Ecology & Hydrology (CEH) led a team of international scientists, who found that increased levels of soluble phosphorus in rivers entering Lake Erie, in the USA, may be linked to conservation measures, despite their success in reducing soil erosion and nutrient losses in particulate forms.

The study shows that since the early 2000s, there has been an increased rate of soluble phosphorus inputs from rivers entering the Western Lake Erie Basin - which has been linked to the increasing extent and severity of harmful algal blooms.

Phosphorus is an essential nutrient for crop production and for terrestrial and freshwater ecosystems. But elevated levels of soluble phosphorus can cause proliferation of algae that produce toxins which can be harmful to fish, other animals and plant life in lakes, rivers and streams. The harmful algae can also impair water that is treated for human consumption.

Lead author Professor Helen Jarvie, a Principal Scientist in Water Quality at the Centre for Ecology & Hydrology, said, "We accounted for changing weather and rainfall patterns, and found increases in river flows alone contributed about one third of the marked increase in soluble phosphorus entering Lake Erie since 2002, despite reductions in fertilizer use and amounts of phosphorus stored in soil. The remaining two thirds must arise from other changes within the watershed."

"We noted that, over time, conservation tillage - where fields are not ploughed, and crop residues remain on the fields before and after planting the next crop, to reduce soil erosion and runoff - has continued an increased trend of adoption since the mid-1980s. It is plausible that the transition from conventional to conservation tillage, along with less incorporation into the soil of broadcast phosphorus fertilizer applications, may have inadvertently caused accumulation of highly-soluble phosphorus at the soil surface.

"This can increase losses of soluble phosphorus during rainfall-induced runoff events, and may also have been compounded by installation of subsurface drainage, which can rapidly transmit the soluble phosphorus from fields to rivers."

She added "These research findings have important implications far beyond the Lake Erie Basin, because conservation tillage is widely recommended as a beneficial management practice for reducing erosion and nutrient losses from cropland in the UK and across Europe and North America."

During the 1980s and 1990s, there were major water-quality improvements in Lake Erie, as a result of the Clean Water Act regulating sewage effluent inputs, improved fertilizer management, and conservation measures, which reduced soil erosion and losses of particulate phosphorus attached to soil particles.

However, in the last 15 years, there has been a decline in water quality, with increases in algal blooms in the Western Basin, linked to the rise in the more ecologically-damaging soluble form of phosphorus. In 2014, a toxic algal bloom in the Western Lake Erie Basin led to a "do not drink" advisory for more than 400,000 people in the city of Toledo, Ohio.

Consequently in 2016, the US and Canadian governments set a new target of reducing levels of phosphorus entering Lake Erie by 40 percent.

Co-author Professor Andrew Sharpley, Professor of Soils and Water Quality at the University of Arkansas, said, "The main lesson learnt is that there can be unintended consequences of changing farm conservation practices, which should be recognized.

"Effective conservation is an adaptive process. In the case of Lake Erie catchments, reduced land tillage dramatically reduced erosion, but without changing fertilizer management practices, this effectively trapped phosphorus at the soil surface.

"There was an eventual transition from soil being a sink for phosphorus to become a source to drainage waters. The implications of this research resonate beyond the Lake Erie Basin and are important to transferring science to the long term benefits of conservation management."

The findings were based on Heidelberg University's 40-year record of daily river-water chemistry for the major rivers draining into the Western Lake Erie basin, and demonstrate the global need for long-term water-quality monitoring to detect change so we can adaptively manage our water resources to ensure their long-term quality and security.

The report published in the Journal of Environmental Quality calls for soil and water quality management approaches which tackle both soluble and particulate phosphorus losses from farmland, and highlights that additional conservation measures will be needed to address the soluble phosphorus component.

The research was funded by the Natural Environment Research Council and was conducted in partnership with the University of Arkansas, Heidelberg University in Tiffin, Ohio, the US Department of Agriculture, and the International Plant Nutrition Institute.
-end-
Notes to editors

Contact details

For interview requests and images contact Wayne Coles, Media Relations Officer, Centre for Ecology & Hydrology, UK, Mobile: +44 (0)7920 2955384, Email: wcoles@ceh.ac.uk

Lead author, Professor Helen Jarvie, Principal Scientist, Water Quality, Centre for Ecology & Hydrology, UK, Office: +44 (0)7920 2955384, Email: hpj@ceh.ac.uk

Co-author, Professor Andrew N. Sharpley, Professor of Soils and Water Quality, University of Arkansas, USA, Office: +001 479-575-5721, Email: sharpley@uark.edu

Images

Photographs of farmland in the Western Lake Erie catchment, the Sandusky River and an algal bloom in the Western Lake Erie Basin are available by contacting CEH
Media Relations Officer Wayne Coles.

Paper reference

Helen P. Jarvie, Laura T. Johnson, Andrew N. Sharpley, Douglas R. Smith, David B. Baker, Tom W. Bruulsema and Remegio Confesor, 2017, 'Increased Soluble Phosphorus Loads to Lake Erie: Unintended Consequences of Conservation Practices?' Journal of Environmental Quality. Doi: 10.2134/jeq2016.07.0248

The paper is available as an open access document via this URL: https://dl.sciencesocieties.org/publications/jeq/abstracts/46/1/123

The Centre for Ecology & Hydrology (CEH) http://www.ceh.ac.uk is the UK's Centre of Excellence for integrated research in the land and freshwater ecosystems and their interaction with the atmosphere. CEH is part of the Natural Environment Research Council, employs more than 450 people at four major sites in England, Scotland and Wales, hosts over 150 PhD students, and has an overall budget of about £35m. CEH tackles complex environmental challenges to deliver practicable solutions so that future generations can benefit from a rich and healthy environment. You can follow the latest developments in CEH research via @CEHScienceNews on Twitter

Centre for Ecology & Hydrology

Related Water Quality Articles:

A watershed moment for US water quality
A new federal rule that determines how the Clean Water Act is implemented leaves millions of miles of streams and acres of wetlands unprotected based on selective interpretation of case law and a distortion of scientific evidence, researchers say in a new publication.
'Pregnancy test for water' delivers fast, easy results on water quality
A new platform technology can assess water safety and quality with just a single drop and a few minutes.
New process could safeguard water quality, environment and health
Swansea University researchers have developed a new way to quickly find and remove wastewater pollutants, which can reduce their impact on the environment.
23 years of water quality data from crop-livestock systems
Researchers summarize runoff water quantity and quality data from native tallgrass prairie and crop-livestock systems in Oklahoma between 1977 and 1999.
Lessening water quality problems caused by hurricane-related flooding
June 1 is the start of hurricane season in the Atlantic, and with 2020 predicted to be particularly active, residents in coastal regions are keeping watchful eyes on the weather.
Control of anthropogenic atmospheric emissions can improve water quality in seas
A new HKU research highlighted the importance of reducing fossil fuel combustion not only to curb the trend of global warming, but also to improve the quality of China's coastal waters.
Pharma's potential impact on water quality
When people take medications, these drugs and their metabolites can be excreted and make their way to wastewater treatment plants.
Study: Your home's water quality could vary by the room -- and the season
A study has found that the water quality of a home can differ in each room and change between seasons, challenging the assumption that the water in a public water system is the same as the water that passes through a building's plumbing at any time of the year.
Researchers create new tools to monitor water quality, measure water insecurity
A wife-husband team will present both high-tech and low-tech solutions for improving water security at this year's American Association for the Advancement of Science (AAAS) annual meeting in Seattle on Sunday, Feb.
How anti-sprawl policies may be harming water quality
Urban growth boundaries are created by governments in an effort to concentrate urban development -- buildings, roads and the utilities that support them -- within a defined area.
More Water Quality News and Water Quality Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at Radiolab.org/donate.