Distribution of some heavy metals in winter wheat at different stages of its development

In the modern world, with its rapid development of industry, environmental pollution by heavy metals is increasing on a scale uncharacteristic of nature. When heavy metals enter the soil in large quantities, they affect the biological and biochemical properties of soils, the change in the amount of mobile forms of nutrients in them. In polluted soils the absorption of heavy metals by plants leads to the accumulation of metals in edible parts of vegetables or crops. The total contamination of the soil is characterized by the gross content of heavy metals, and the availability of elements for plants is determined by their mobile forms. According to the calculation of the geoaccumulation index for the studied elements, the following series of metals have been compiled according to their contribution to soil pollution: Cu > Zn > Fe > Mn. The quantitative measure of the accumulation intensity of chemical elements by plants from the soil is the accumulation coefficient, describing the degree of biofilicity of the elements, as well as intensity of their involvement in biological cycles. The accumulative abilities of roots and shoots in relation to zinc at different stages of wheat growth decrease in the following order: earing > ripening > tubing. However, for copper there is a gradual decrease in accumulation in the roots at different stages of wheat growth in the following order: earing > tubing > ripening; in shoots it is: ripening> tubing > earing. According to the results of the study, several series of metals have been worked out according to the ability of accumulation by winter wheat. The calculated value of the transition coefficient allows us to formulate the following conclusions: iron reaches the maximum value of the coefficient at the tubing stage (7.764) and has the greatest value among all elements and growth stages; zinc and manganese reach the maximum value of the coefficient at the earing stage (1.765 and 2.193, respectively); copper reaches it at the ripening stage (1.143).