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 Energy crop production on conservation lands may not boost greenhouse gases
13.03.2017 | Penn State

nachricht How nature creates forest diversity
07.03.2017 | International Institute for Applied Systems Analysis (IIASA)

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: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>