Interrelation between climatic changes and content of heavy metals in Chernozem soils of Saratov oblast, Russia

摘要

This work is aimed at investigation into trends and intensities of geochemical processes leading to accumulation and redistribution of heavy metals (Fb, Zn, Cd, Cu, Hg, Ni) in cultivated land of Saratov oblast (Russia). Field tests were performed in the years 1990-2016 on southern chernozem with crop rotation involving alfalfa (Medicago sativa L.) on various elements of cultivated land, ground waters and plants. The obtained results revealed interrelation between climate changes and increase in ratioof immobile forms (soluble in In HC1) to mobile forms (soluble in ammonium acetate buffer with pH 4.8) of heavy metals. The role of leaching in increase in content of mobile forms of heavy metals in ground waters is demonstrated: by 8.3-9 times in wellsadjacent to buffer elements of cultivated land (virgin land and forest belt) and by 19.5 times in well on arable land. In the field tests under the action of mineral (NjJP^K^ ha yearly) and organic (cattle manure, 60 t/ha) fertilizers cumulative yield of copper, zinc, cadmium, lead, and nickel with alfalfa crop (Medicago sativa L.) increased in average by 33.1%.