Application of biological methods to assess the toxicity of soils contaminated with heavy metals and the effectiveness of stabilisation processes

Short-term biotests were used to determine the effectiveness of the use of compost and fly ash in the stabilization of heavy metals in contaminated soil. For this purpose, in two independent experiments, either compost (3:1) or fly ash (1:1) were added to soil contaminated with heavy metals. To assess seed germination and root elongation of Sorghum saccharatum L., Lepidium sativum L., Sinapis alba L. after three days a Phytotoxkit test was used. Seedling emergence and biomass yield after 21 days were evaluated. Obtained data indicate better practical applicability of the seedling emergence test thanks to the longer duration resulting in more reliable conclusions provided in that test. A short, 3-day test did not confirm any effective stabilizing role of theapplied additives. Sorghum saccharatum L. turned out to be most sensitive to the altered soil conditions, while Lepidium sativum L. was most tolerant.