The study of the dynamics, mobility and bioavailability of zink, deposited as a trace element in the system “soil - soil solution - crop plants”

The aim of the work was to assess the parameters of effective diffusion and convective transport (mass transfer) of zinc ions in the roots of broad beans ( Vicia faba L.) varieties ‘Yantarnye”, as well as to study the dynamics of the processes of biomass growth of plants, changes in the concentration of Zn in the aboveground parts and roots, removal of the metal with biomass. Methods. The properties of the investigated soddy-podzolic sandy loam soil with the help of conventional methods are determined, model experiments on the study of diffusion of Zn, as well as water-balance vegetation experiments with broad beans are carried out. During the growing season, quasi-equilibrium soil solutions were extracted by centrifugation. Results . Data on the dynamics of Zn concentration in aboveground parts and roots of broad beans and metal removal with aboveground biomass were obtained. Quantitative parameters and formal dependences of the process of root uptake of Zn by plants on time are determined. Their interrelation with dynamics of the content of water-soluble forms of Zn easily accessible to plants in soils is established. The values of migration indicators - the rate of moisture uptake v (H₂O), the effective diffusion coefficient of zinc ( D_ef), the rate of mass flow (transfer) of dissolved zinc ions ( v (Zn)) into the roots of plants with a convective flow of moisture depending on the age of broad beans, were determined. Conclusion. It was found that almost all Zn absorbed by plants enters through the root system as a result of mass transfer processes with a convective flow of moisture (diffusion mechanism of Zn entering the roots of plants plays a secondary role). The obtained parameters can be used to model the processes of root uptake of HM by plants.

broad beans, zinc, above-ground biomass, roots, specific surface area, concentration, removal with crop, transpiration, effective diffusion, convective flow, mass transfer