o:8303 Trace elements in the soil-plant system: Alfalfa and nickel case study en Abstract: In Serbian soils, nickel (Ni) and chromium (Cr) are found in elevated concentrations over significant areas, often these elements origin is geochemical (from basic and ultrabasic rocks which account for about 4% of territory), but it can also be the result of anthropogenic pollution. Elevated Ni and Cr concentrations often occur in soils, which are generally suitable for agricultural production, including alfalfa cultivation. With the aim to select the nickel contaminated soil, agricultural soils from 15 locations in the central part of the country were examined for basic soil properties, and content and solubility of heavy metals. The soils with contrasting Ni concentrations (with slightly elevated and remediation Ni concentrations) were selected for further monitoring of alfalfa-soil interactions and elements translocation. The both soils were slightly acidic, moderately supplied with humus, nitrogen and available potassium, with clay mechanical composition. In addition, the inoculation with effective nitrogen-fixing bacteria rhizobia was performed at the beginning of trial, to ensure stable yields, and to examine the effect of strains on the accumulation of trace metals in the above-ground part of plants. Lower solubility of metals in weakly acidic soil and adsorption on clay minerals possibly affected the lower mobility and accessibility of elements in the soil. There is a pronounced accumulation of elements in the roots of the plant, which is confirmed by the translocation factor, which is generally less than 1. The Ni concentrations in alfalfa shoots varied depending on the strain, soil Ni and growing conditions, where inoculation with some strains reduced the Ni concentration compared to uninoculated plants. Concentrations of all tested elements were mostly in the range of common values for plants. In the soil with a higher content of Ni and Cr, significantly higher concentrations of these elements were found in all treatments, but a greater mass of alfalfa was also measured. The results indicate that inoculation of alfalfa with effective rhizobial strains showed potential for improvement of plants growth and phytostabilisation of trace elements in the soils. Further research is necessary to enable a better explanation of the relationships in the soil-plant-microorganisms system. Soil, rhizobia, trace elements, alfalfa, soil quality. 1552100 978-84-09-75471-7 2025-10-10T12:09:15.765Z 44 no 46 Mira Milinkovic Institute of Soil Science 0000-0001-5175-6842 46 Vesna Mrvic Institute of Soil Science 0000-0002-6666-0875 46 Mila Pešic Institute of Soil Science 0000-0001-7589-9100 46 Sonja Tošic Jojevic Institute of Soil Science 0000-0002-3865-6529 46 Snežana Andjelkovic Institute for Forage Crops, Kruševac, Serbia 0000-0003-0436-3530 46 Biljana Sikiric Institute of Soil Science 0000-0002-8308-4582 46 Olivera Stajkovic-Srbinovic Institute of Soil Science 0000-0001-9759-843X application/pdf 5758843 https://unilib.phaidrabg.rs/o:8303 no yes 1 70 92000004 71A05 Book of Abstracts: Advancing Soil Knowledge for a Sustainable Future – “EUROSOIL 202”. Seville – Spain, September 8 – 12, 2025. 763 763 2025