Trace element contents in spring barley ( L.) and white mustard ( L.) following the remediation of cobalt-contaminated soil.

The study was undertaken to determine the effects of various substances (manure, clay, charcoal, zeolite, and calcium oxide) applied to a cobalt-contaminated soil (0, 20, 40, 80, 160 and 320 mg kg of soil) on the content of certain trace elements in spring barley (main crop) and white mustard (after-crop). The effect of cobalt on the contents of the trace elements was ambiguous and was either antagonistic or synergistic in nature, depending on the organ and plant species. Generally, the substances applied to soil reduced the content of most trace elements in above-ground parts of both plants and in the roots of white mustard, in contrast to the roots of spring barley. Of all the substances, calcium oxide had the strongest and generally reducing effect on the content of trace elements in the tested organs of the plants; however, its effect was the weakest in the roots of white mustard. It is difficult to find in the literature the results of studies into the effect of mineral and other amendments used in our research (manure, clay, charcoal, zeolite, and calcium oxide) on trace elements content in plants if they are used with a view to weakening the effect of cobalt on plants. We think that it is the novelty in the results of environmental sciences. The literature refer to the application of organic matter, bentonite, zeolite and calcium oxide to neutralize other heavy metals. The research was carried out in the two plants system used for phytoremediation with main crop (spring barley- L.) and after-crop (white mustard- L.). The trace elements were analyzed in test plants. The results of the research allowed to select the most effective substance to support the phytoremediation of soil contaminated with cobalt.