Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Spreading phosphate fertilisers contaminates fields with Uranium


Phosphorus (P) is a vital mineral for all crops. Farmland has to be supplied with phosphorus regularly by applying fertiliser, in order to provide crops with sufficient phosphorus. P fertilisers are produced out of rock phosphates by means of different processes from sedimentary (fossil) or magmatic deposits. Rock phosphates from sedimentary deposits are characterised by a high content of elements which can also be detected in standard fertilisers.

Scientists at the Institute of Plant Nutrition and Soil Science of the Federal Agricultural Research Center in Braunschweig, Germany have found that commercial P-fertilisers also contain the toxic radionuclide uranium (U). From their own analyses and extensive literary enquiries they have discovered that because of the high affinity of U to phosphorus, the U content originally contained in the rock phosphates of 13- 75 mg/kg, during the reprocessing to super- or triple-superphosphorus raises to 85-191 mg/kg. Fertilizers with two-nutrients (NP or PK) contain 89-96 mg/kg U, NPK-fertilisers 14 mg/kg U. Sewage-sludges reaches a content of 4-32 mg/kg U. Fertilisers without any P components (N-, K-, NK-, Mg-, S- and lime fertiliser) have contents of more than 1 mg/kg U. But, remarkably, in spite of their significant P content, farmyard manures and slurries are only slightly contaminated with U (seldom above 2 mg/kg U).

U is the heaviest naturally occurring chemical element and as a radioactive alpha-emitter and toxic heavy metal is recognised as a risk for human health and the environment. The German scientists say that this doubly increased threat has been unrecognised until now.

As a natural element U occurs in all areas of life and in very different concentrations and therefore it represents one of the basic dangers in life. U mainly accumulates in bones and can cause several diseases ranging from functional disturbances of the kidneys, lungs and liver, to cancer and mutations. The probability of such fatal effects on health is a function of the amount of U taken up by the organism i.e. the risk increases with the duration and amount of intake. That is one reason why there are no definite limits in respect to health consequences of U pollution.

For the last 50 years the amounts of U released into the environment by human activities, have been increasing and with them the danger of raised pollution in the food chain. The main cause of U discharge to agricultural soils is fertilisation with mineral P sources. The scientists of FAL calculated that a typical P-fertiliser application of 22kg/ha P with mineral P-fertilisers (an amount in accordance with international Codes of Good Agricultural Practice) would spread 10-22 g/ha U on to treated fields each year. But hardly more than 1 g/ha Uranium is removed by crop products, leaching and erosion.

So, when applying mineral P-fertiliser, the accumulation of U in the soil is inevitable. With increasing amounts of U in the soil, there is the increased absorption of Uranium by plants in the food chain and a consequent deterioration in food quality.

By contrast, where P is applied by farmyard manures and slurry, the amounts of U applied to the soil are nearly equal to those removed by natural processes. Against this background P-fertilising with a farms own fertilisers is preferable to a supply of P with mineral fertilisers.

Further information can be found in Uran- Umwelt- Unbehagen" in the FAL from 25th November 2004 under "workshops"

Or contact: Prof. Dr. Dr. Ewald Schnug, Federal Agricultural Research Center (FAL), Institute of Plant Nutrition and Soil Science (FAL), Bundesallee 50, 38116 Braunschweig, E-mail:

Margit Fink | idw
Further information:

More articles from Agricultural and Forestry Science:

nachricht Unique communication strategy discovered in stem cell pathway controlling plant growth
23.03.2018 | Cold Spring Harbor Laboratory

nachricht “How trees coexist” – new findings from biodiversity research published in Nature Communications
22.03.2018 | Technische Universität Dresden

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>