Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Spreading phosphate fertilisers contaminates fields with Uranium

11.08.2005


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"
in: http://www.pb.fal.de/index.htm?page=/home.htm

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: pb@fal.de

Margit Fink | idw
Further information:
http://www.pb.fal.de/index.htm?page=/home.htm

More articles from Agricultural and Forestry Science:

nachricht Researchers discover a new link to fight billion-dollar threat to soybean production
14.02.2017 | University of Missouri-Columbia

nachricht Important to maintain a diversity of habitats in the sea
14.02.2017 | University of Gothenburg

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Start codons in DNA may be more numerous than previously thought

21.02.2017 | Life Sciences

An alternative to opioids? Compound from marine snail is potent pain reliever

21.02.2017 | Life Sciences

Warming ponds could accelerate climate change

21.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>