THE EFFECT OF BISMUTH POLLUTION ON THE PHYTOTOXICITY OF THE SOILS IN SOUTHERN RUSSIA
Bismuth (Bi), for half a century is one of the most technophilic elements. Its high content is recorded in all components of the environment and on almost all continents. When bismuth accumulates in the soil, it is deposited in the organs of various plants. The main sources of bismuth pollution of the environment and soil cover are the metallurgical industry, cement plants, motor transport, coal thermal power plants (TPP). However, the influence of bismuth on the biological properties of soils and ecological status is poorly understood. It seems relevant to identify patterns, mechanisms and possible consequences of the influence of bismuth on the state of the soil, the establishment of limits of soil resistance to pollution, regulation of bismuth content. The aim of the work was to study the influence of bismuth pollution on phytotoxic properties of soils in the South of Russia. The object of study selected soils typical of the South of Russia: ordinary Chernozem, brown forest soil and light loamy Chernozem. For model studies, soil samples were taken from the upper arable layer (0-20 cm), since it retains most of the pollutants, including heavy metals. Bismuth contamination was simulated in the laboratory. The study element made in the form of a solution of nitrate of bismuth (III) 5-water at concentrations of 3.36 mg/kg, or 33.6 mg/kg and 336 mg/kg. the experiment was in 3 multiple biological replicates. Phytotoxic properties of soils were evaluated in the work, as they are the first to react to external chemical effects. Laboratory and analytical studies were carried out using generally accepted methods in biology, soil science and ecology. The seeds of radish (Raphanus sativus L.) variety "16 days"were used as a biological model. In the process of studying the influence of bismuth on three types of soils typical for the southern regions of Russia, a decrease in phytotoxic parameters was observed. The inhibition of germination and growth of the root system of radish plants when introducing the studied doses of the element into the soil was noted. However, the germination of radish seeds on Chernozem ordinary heavy loam when contaminated with doses of 1 and 10 UDC for a short (10 days) and long term (90 days) did not differ from the control. 10 UDC and 100 UDC were more toxic for light loamy Chernozem than for ordinary Chernozem and brown forest soil. The degree of resistance to pollution bismuth is formed in the following range: ordinary black-soil> brown forest> black soil is light loam. This is probably due to the fact that ordinary Chernozem has a neutral reaction medium (pH), contains more humus, and brown forest soil - has an acidic environment. The black soil is light loam was the most sensitive object to pollution bismuth, because it has a smaller margin of organic matter and easier grading.