Content of Toxic Elements after Introduction of Phosphogypsum and Litter into Slightly Eroded Agrochernozem

Abstract

When using by-products and wastes of industrial and agricultural production (phosphogypsum (PG) and turkey litter (TL)) as a fertilizer, it is necessary to take into account not only the content of nutrients, but also environmental safety, including the presence of toxic elements. A small-plot field experiment was conducted on slightly eroded agrochernozem in the forest-steppe zone of the Bashkir Cis-Urals. PG was applied once at doses of 5, 10, and 20 t/ha; TL – in doses of 40 and 60 t/ha; organo-mineral fertilizer (OMF) – 40 and 60 t/ha at ratios of PG and TL 1 : 10, 1 : 5 and 1 : 2. After applying of PG, TL, or OMF into the soil, the content of As, Cd, Hg, Se, Mo, Sb, W, and V remained at the trace level. The content of Zn, Ni, Cu, Ba, and Mn remained practically unchanged compared to the control variant, but was significantly higher than in the initial PG. The content of Pb and Sr increased mainly with the addition of high doses of PG, while those of Co and Cr increased with high doses of TL. In general, the content of elements of three toxicity classes did not exceed the MPC, the total effect of pollution was assessed as permissible.