Regulations and guidelines for tolerable concentrations of these potentially plant-toxic elements in soils are based on the assumption that the toxic effects of the metals are substantially independent and not additive.
However, additivity would imply that soil tolerance limits for each metal must be adjusted to compensate for the presence of another metal. There has been very little experimental work to date to provide a basis for determining the degree to which copper-zinc interaction in soils is additive as defined by the toxicity response in crops.
Researchers at Cornell University have investigated the copper-zinc interaction in two soils with different textures, using soybean growth and metal uptake into leaves to evaluate both toxicity and availability of these metals to the plants. Soybean crops were grown in pots in the field in two successive years after allowing copper and zinc sulfate-amended soils to age in the field for one year prior to the first planting. Copper and zinc were added to individual soils to provide 0, 50,100, 200, and 400 mg/kg of each metal as well as every possible combination of addition levels of the two metals. The results from the study are published in the November-December issue of Journal of Environmental Quality.
Interactive effects of copper and zinc were observed both in the soil as well as in the soybean toxic response. In the soil, high copper had a strong effect on inhibiting zinc adsorption on soil particles, thereby causing zinc to be more easily extractable and available. Conversely, there was only a moderate interactive effect of zinc on copper adsorption, probably explained by the higher affinity of copper for soil adsorption sites, particularly those associated with organic matter.
The toxic effects of copper and zinc on soybean growth was found to be additive to a large degree, as measures of both extractable copper and zinc in the soils were needed to adequately explain the inhibition of plant growth over all treatments. However, the toxic effect of copper was stronger than that of zinc, possibly explained by the observed severe impact of copper on soybean root development. Soil texture had a marked influence on the degree of copper and zinc toxicity and availability to soybeans, consistent with numerous studies that have shown coarse-textured soils to be more susceptible to the toxic effects of heavy metals on crops.
The results from the study indicate that guidelines for tolerable upper limits of copper and zinc concentrations in soils are likely to require allowance for the presence of a second toxic metal at elevated concentrations, which could lower the tolerable limit for either copper or zinc. Furthermore, tolerable limits for copper and zinc in soils are likely to be lower in coarse-textured soils.
The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://jeq.scijournals.org/cgi/content/abstract/38/6/2253.
The Journal of Environmental Quality, http://jeq.scijournals.org is a peer-reviewed, international journal of environmental quality in natural and agricultural ecosystems published six times a year by the American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and the Soil Science Society of America (SSSA). The Journal of Environmental Quality covers various aspects of anthropogenic impacts on the environment, including terrestrial, atmospheric, and aquatic systems.
The American Society of Agronomy (ASA) www.agronomy.org, is a scientific society helping its 8,000+ members advance the disciplines and practices of agronomy by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.
Sara Uttech | Newswise Science News
Kakao in Monokultur verträgt Trockenheit besser als Kakao in Mischsystemen
18.09.2017 | Georg-August-Universität Göttingen
Ultrasound sensors make forage harvesters more reliable
28.08.2017 | Fraunhofer-Institut für Zerstörungsfreie Prüfverfahren IZFP
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...
Scientists from the MPI for Chemical Energy Conversion report in the first issue of the new journal JOULE.
Cell Press has just released the first issue of Joule, a new journal dedicated to sustainable energy research. In this issue James Birrell, Olaf Rüdiger,...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
19.09.2017 | Event News
19.09.2017 | Physics and Astronomy
19.09.2017 | Power and Electrical Engineering