Impact of Bottom Sediments on Assimilability of Copper and Zinc in Light Soil

Abstract

The aim of the research was to evaluate an effect of bottom sediment addition on the content of soluble forms of copper and zinc in light soil as well as to evaluate the bioaccumulation of these elements by energetic plants, ie Miscanthus giganteus and Sida hermaphrodita. In order to reach the research goal, a field experiment was set up in autumn 2010 in Lipie near Rzeszow using the method of random blocks. The experimental design included 3 doses of the bottom sediment added to soil and a control treatment without sediment supplement. Doses of the bottom sediment were calculated based on soil hydrolytic acidity and the content of calcium carbonate in the sediment. The bottom sediment used in the experiment was taken from the Rzeszow Reservoir and was characterized by alkaline reaction and silt texture. Moreover, it showed an 8-times greater content of soluble forms of copper and zinc in comparison to the experimental soil. The soil of experimental field had granulometric composition of weakly clayey sand with very acid reaction (pHKCl = 4.53), as well as low content of soluble and bioavailable forms of copper and zinc. Miscanthus giganteus and Sida hermaphrodita were chosen for test plants. In autumn 2011 and 2012, soil samples were collected from the experimental plots. In those samples, the contents of copper and zinc soluble forms extracted with 1 mol HCl dm were determined according to Rinkis method. The content of copper and zinc in soil samples and the above-ground parts of plant was determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES). On the basis of the obtained results, the bioaccumulation factor [BF] of both metals in the above-ground plant biomass was calculated. The obtained results were elaborated statistically using a one-way analysis of variance and Tukey’s test at a significance level of = 0.01. The addition of the bottom sediments to the light soil caused a change its reaction in all the experimental treatments in relation to the control treatment. The applied doses of bottom sediments did not cause exceeding the permissible concentrations of copper and zinc in the examined soil. The content of available for plants soluble forms of copper and zinc in light soil under Miscanthus giganteus and Sida hermaphrodita cultivation increased as consequence of rising bottom sediment doses introduced to the substratum. The addition of the bottom sediments to the soil resulted in a decrease of values of the bioaccumulation factor of copper and zinc in selected energetic plants.