Environmental aspects of remediation of lead-contaminated soils: the role of biological methods in restoring soil biodiversity and ecosystem functions

The intensification of agricultural production and anthropogenic stress lead to the accumulation of heavy metals in the soils of agrocenoses, among which lead (Pb) poses the greatest threat to product safety and sustainability of ecosystems. The problem of remediation of such lands without their decommissioning is an urgent task of agricultural ecology. In contrast to highly specialized hyperaccumulative plants, which are of little use for large-scale applications, widespread agricultural crops with high biomass are of particular interest. Corn (Zea mays L.) meets these requirements and is considered as a promising object for phytomelioration. This article substantiates the potential role of corn in the restoration of lead-contaminated agricultural land. The physiological and biochemical mechanisms of tolerance of this culture to Pb ions, including metal accumulation in the roots, binding by its cell walls and sequestration by vacuoles, are considered. Two main areas of corn use are analyzed: phytostabilization (immobilization of lead in the rhizosphere and prevention of its entry into food chains) and phytoextraction (extraction of metal from the soil followed by utilization of biomass for technical purposes, for example, for the production of bioethanol or biochar). Special attention is paid to agrotechnical techniques that increase the effectiveness of remediation: the use of soil conditioners (zeolites, phosphorous flour, organics), inoculation of seeds and the rhizosphere with rhizobacteria (PGPR) strains that increase plant stress resistance and bioavailability of metals. It is shown that the integration of corn into adaptive landscape farming systems makes it possible to combine the tasks of ecological remediation and the production of economically useful products, which is the key to the economic feasibility of restoring polluted agrocenoses. Keywords: HEAVY METALS, LEAD, SOIL POLLUTION, AGRICULTURAL LANDS, PHYTOMELIORATION, CORN (ZEA MAYS L.), PHYTOSTABILIZATION, PHYTOEXTRACTION, RHIZOSPHERIC MICROORGANISMS, AGROTECHNICAL TECHNIQUES