POSSIBLE METHODS FOR DETERMINING SOIL PHYTOTOXICITY USING BIOINDICATION METHODS

Abstract

The article analyzes three approaches to bioindication of phytotoxicity of soils: the method of seedlings, the method of soil plates and the method of water extracts. The sprouting method is convenient for quick diagnosis, as it requires a minimum of equipment and gives results in 3-7 days. The soil plate method is more accurate because the seeds are in direct contact with the solid phase of the soil, including sorbed pollutants. Water extracts have shown the least sensitivity and are not recommended for soil assessment, except for liquid media. The choice of test plants (radish, mustard, watercress, oats, plantain) significantly affects the result, since their reaction to heavy metals, petroleum products and other pollutants varies. Using the example of urban soils, it is shown that phytotoxicity is 10-20% in recreational areas, about 40% in residential areas, and 70-100% in industrial and transport areas. The biogenic factor (rhizosphere effect, micromycetes) can both enhance and weaken the manifestations of toxicity, which must be taken into account when interpreting the data. For a reliable integral assessment, several test cultures from different families should be combined and at least two methods should be used.