Navigation Links
Nitrogen fertilizer remains in soils and leaks towards groundwater for decades, researchers find
Date:10/21/2013

Nitrogen fertilizer applied to crops lingers in the soil and leaks out as nitrate for decades towards groundwater "much longer than previously thought," scientists in France and at the University of Calgary say in a new study.

Thirty years after synthetic nitrogen (N) fertilizer had been applied to crops in 1982, about 15 per cent of the fertilizer N still remained in soil organic matter, the scientists found.

After three decades, approximately 10 per cent of the fertilizer N had seeped through the soil towards the groundwater and will continue to leak in low amounts for at least another 50 years.

The study was led by researcher Mathieu Sebilo at the Universit Pierre et Marie Currie in Paris, France, and by Bernhard Mayer in the U of C's Department of Geoscience, and included several research organizations in France.

Their paper, "Long-term fate of nitrate fertilizer in agricultural soils," was published this week in the Proceedings of the National Academy of Sciences of the United States of America.

The findings show that losses of fertilizer N towards the groundwater occur at low rates but over many decades, says Mayer, U of C professor of geochemistry and head of the Applied Geochemistry Group.

That means it could take longer than previously thought to reduce nitrate contamination in groundwater, including in aquifers that supply drinking water in North America and elsewhere, he says.

"There's a lot of fertilizer nitrogen that has accumulated in agricultural soils over the last few decades which will continue to leak as nitrate towards groundwater," Mayer says.

Canada and the U.S. regulate the amount of nitrate allowed in drinking water. In the 1980s, surveys by the U.S. Environmental Protection Agency and the U.S. Geological Survey showed that nitrate contamination had probably impacted more public and domestic water supply wells in the U.S. than any other contaminant.

Mayer is an internationally recognized expert in the use of stable isotopes to track contaminants in the environment.

The French-U of C study is the first that tracks, using stable isotope "fingerprinting," the fate of fertilizer N remaining in the soil zone over several decades.

The research team used a stable isotope of nitrogen, N-15, as a tracer to track fertilizer nitrogen applied in 1982 to sugar beet and winter wheat crops on a pair of two-metre-square plots at a site in France.

Over the 30-year study, the researchers measured the amount of N-15 labelled fertilizer N taken up by plants and they quantified the amount of fertilizer N remaining in the soil.

The novel aspect of their study was that they subsequently determined the long-term fate of this fertilizer N 'pool' retained in the soil. Their measurements of seepage water from locations two metres deep in the soil revealed the amount of fertilizer nitrate leaking towards the groundwater.

The team found that 61 to 65 per cent of the N-15 fertilizer applied in 1982 was taken up by the sugar beet and wheat plants over the 30-year study.

However, 32 to 37 per cent of the fertilizer N remained in the soil organic matter in 1985 or three years after application, while 12 to 15 per cent still lingered in the soils after three decades.

Between eight to 12 per cent of the fertilizer N applied in 1982 had leaked in the form of nitrate toward groundwater during the 30 years, and will continue to leak at low rates "for at least another five decades, much longer than previously thought," the study says.

The scientists predict that about 15 per cent of the initially applied fertilizer N will be exported from the soils towards the groundwater over a time span of almost one century after the 1982 fertilizer application.

Mayer speculates that if the same research were done in Alberta, the findings would be similar in terms of fertilizer uptake by plants and nitrogen retention in the soils, although Alberta's comparatively dry climate and different geology might slow the rate of nitrate seeping towards the groundwater.

Nitrate contamination of aquatic ecosystems can be reduced by farmers following the 4Rs of nutrient stewardship: applying the right fertilizer source at the right rate, the right time and the right place (see http://www.nutrientstewardship.com/what-are-4rs).


'/>"/>

Contact: Marie-Helene Thibeault
m.thibeault@ucalgary.ca
403-679-8447
University of Calgary
Source:Eurekalert  

Related biology news :

1. Microbes capture, store, and release nitrogen to feed reef-building coral
2. Nitrogen has key role in estimating CO2 emissions from land use change
3. Global nitrogen availability consistent for past 500 years, linked to carbon levels
4. Nitrogen from pollution, natural sources causes growth of toxic algae, study finds
5. Lower nitrogen losses with perennial biofuel crops
6. Researchers to study impacts of pollutant nitrogen on plant species diversity
7. How much nitrogen is fixed in the ocean?
8. Scientists develop new carbon accounting method to reduce farmers use of nitrogen fertilizer
9. Nitrogen pollution changing Rocky Mountain National Park vegetation, says CU-Boulder-led study
10. Modern hybrid corn makes better use of nitrogen, study shows
11. Vetch cover crop, fertilizer practices recommended for organic zucchini
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Nitrogen fertilizer remains in soils and leaks towards groundwater for decades, researchers find
(Date:2/14/2017)...  Wake Forest Baptist Medical Center today announced Julie Ann ... officer (CEO). Freischlag joins the medical center on May ... M.D., who last year announced that he would transition ... leading it since 2008.   As CEO, ... Baptist,s academic health system, which includes Wake Forest School ...
(Date:2/13/2017)... Former 9/11 Commission border counsel and Special Counsel to ... of Identity Strategy Partners, LLP, today releases the following ... Protecting the Nation From Foreign Terrorist Entry Into the ... Trump,s ,Travel Ban, Executive Order gains more notoriety and ... ban, it is important that our national discourse regain ...
(Date:2/9/2017)... 9, 2017 The biomass boiler market report ... biomass boiler market globally in terms of revenue (US$ ... The market for biomass boilers has been segmented on ... and country/region. The market based on feedstock type, has ... biogas & energy crops, urban residues, and others. On ...
Breaking Biology News(10 mins):
(Date:2/23/2017)... it seems everyone has a chance to express their personalities. ... and dynamic community unlike any other. The businesses that succeed ... With their newest salon in Dunwoody ... that tradition with a unique, fresh approach to head lice ... newest of 13 nationwide locations, each of them well-situated in ...
(Date:2/23/2017)... 2017  Imanis Life Sciences announced today the ... vaccinia viruses for virotherapy research. These viruses are ... proprietary, vaccinia virus-based technology platform for research use. ... a partnership with Genelux to offer researchers, for ... use in research," said Dr. Kah Whye ...
(Date:2/23/2017)... ... February 23, 2017 , ... ... today that in a published evaluation of multiple immunoassay-based threat detection technologies ... of Energy Laboratory, PathSensors’ CANARY® biosensor threat detection technology was found to ...
(Date:2/23/2017)... ... 23, 2017 , ... Today, researchers can fast-track sample collection ... and/or other biomarkers or SNPs of interest) using one, easy-to-collect saliva sample. With ... relationship between insulin and other relevant biomarkers can be extensively studied through a ...
Breaking Biology Technology: