Role of feather reed grass (Calamagrostis acutiflora) in phytoremediation of urban soils.

Samples of soil and aerial mass of Calamagrostis acutiflora were obtained from an urban area adjacent to a street. The sampled material was analyzed to determine the content of Fe, Mn, Zn, Cu, Pb, Cd, Ni, Cr and Co, in addition to which soil was analyzed for the content of total organic carbon (TOC), salinity (EC) and reaction (pH). Based on the results, the enrichment factor (EF) and biological accumulation coefficient (BAC) of heavy metals as well as correlations between the analyzed characteristics were calculated. The content of heavy metals in the soil did not exceed the standards set for transportation areas, but the EF value implicated anthropogenic enrichment of soils with Zn, Cu, Pb, Cd and Co. Numerous, highly significant and positive correlations were obtained between the content of the elements in the soil, plants and in the soil-plant system, which suggests their relatively high bioavailability. The BAC values achieved for Co, Cr, Cu, Cd and Ni indicate that Calamagrostis acutiflora can be a useful species for phytoextraction of these elements from urban soils. Moreover, Calamagrostis acutiflora is a good choice for planting in urban areas due to its good adaptability, long growing season and tall conformation.

This study enabled us to the determine the usefulness of Calamagrostis acutiflora for phytoextraction of heavy metals (Fe, Mn, Zn, Cu, Pb, Cd, Ni, Cr and Co) from urban soils exposed to transportation pressure. This aspect of the said grass species has not been evaluated previously; meanwhile, owing to its high esthetic value, the grass can be an interesting choice in the landscaping of urban areas. The evaluation was based on determinations of the elements in the soil and in aerial biomass of Calamagrostis acutiflora sampled from an urban area adjacent to a busy street. The phytoremediation potential of Calamagrostis acutiflora was assessed according to the calculated biological accumulation coefficient (BAC). Furthermore, the enrichment factor (EF) for the heavy metals in the soil was determined, which enabled us to identify the extent of anthropogenic pressure in this area. Other determinations included basic soil physicochemical properties (TOC, pH, EC), which in practice will facilitate a choice of sites to be planted with Calamagrostis acutiflora in the future.

Evaluation of the impact of soil contamination with mercury and application of soil amendments on the yield and chemical composition of Avena sativa L.

The purpose of this study was to determine the effect of soil contamination with Hg on the yield and chemical composition of Avena sativa L. Mercury was incorporated into soil in amounts: 0, 50, 100 and 150 mg Hg·kg-1of soil. Zeolite, lime and bentonite were used to alleviate the soil contamination. Plants cultivated in Hg-polluted soil showed growth inhibition even in the presence of bentonite, lime or zeolite. Under elevated doses of Hg, the yield of aerial mass and roots decreased. The soil amendments mitigated the adverse effect of contamination, with lime and bentonite having a more beneficial influence on the yield than zeolite. The incremental contamination with mercury led to an increase in the content of Hg in the biomass of the plants. A much higher content of Hg was found in roots than in aerial parts. The inactivating substances applied to soil to some extent limited the increase in the content of this metal in all plant organs. Lime proved to be most effective in this regard. An increase in the soil contamination with mercury caused an increased content of nitrogen and potassium in plant organs and a decrease content of phosphorus.

Effect of soil contamination with fluorine on the yield and content of nitrogen forms in the biomass of crops.

The research was based on a pot experiment, in which the response of eight species of crops to soil contamination with fluorine was investigated. In parallel, some inactivating substances were tested in terms of their potential use for the neutralization of the harmful influence of fluorine on plants. The response of crops to soil contamination with fluorine was assessed according to the volume of biomass produced by aerial organs and roots as well as their content of N-total, N-protein, and N-NO3-. The following crops were tested: maize, yellow lupine, winter oilseed rape, spring triticale, narrow-leaf lupine, black radish, phacelia, and lucerne. In most cases, soil pollution with fluorine stimulated the volume of biomass produced by the plants. The exceptions included grain and straw of spring triticale, maize roots, and aerial parts of lucerne, where the volume of harvested biomass was smaller in treatments with fluorine-polluted soil. Among the eight plant species, lucerne was most sensitive to the pollution despite smaller doses of fluorine in treatments with this plant. The other species were more tolerant to elevated concentrations of fluorine in soil. In most of the tested plants, the analyzed organs contained more total nitrogen, especially aerial organs and roots of black radish, grain and straw of spring triticale, and aerial biomass of lucerne. A decrease in the total nitrogen content due to soil contamination with fluorine was detected only in the aerial mass of yellow lupine. With respect to protein nitrogen, its increase in response to fluorine as a soil pollutant was found in grain of spring triticale and roots of black radish, whereas the aerial biomass of winter oilseed rape contained less of this nutrient. Among the analyzed neutralizing substances, lime most effectively alleviated the negative effect of soil pollution with fluorine. The second most effective substance was loam, while charcoal was the least effective in this respect. Our results showed the effect of soil contamination with fluorine on the yield and chemical composition of fluorine depended on the species and organ of a tested plant, on the rate of the xenobotic element and on the substance added to soil in order to neutralize fluorine.