EN
The biology and chemistry of the soil-root interface (rhizosphere) has recently received increased attention. Of special interest is the identification and quantification of organic and inorganic root exudates, which may alter the flow of nutrients in the rhizosphere mainly via soil pH and ionic concentration changes in the rhizosphere soil. Release of inorganic ions, such as H⁺ abd HCO₃⁻ , resulted from ion uptake by roots directly affects the pH of rhizosphere soil what can modify the acquisition of nutrients by plants. Exudation of organic compounds by roots may influence the ion solubility and uptake through their indirect effects on microbial activity, physical properties of rhizosphere and dynamics of root growth and directly through the acidification, chelation, precipitation and oxidation-reduction reactions in the rhizosphere. Plant roots release a variety of organic substances; however, the water soluble compounds are most readily decomposable substances which serve as a source of nutrients for microbial populations of microorganisms colonizing root surface. The microorganisms in turn can affect the growth and physiology of plants either directly via various microbial metabolites or by modifying the soil-root interface environment. Although the rhizosphere studies are difficult, understanding the biology and chemistry of rhizosphere is essential to determining the mobility and availability of mineral elements at the soil-root interface and their impact on plant nutrition.