Heavy metal reserves in the arable layer of the High Zavolzhye soils

The arable layer of the High Zavolzhye soil-cover contains heavy metals (As, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Rb, Se, Sr, Ti, V, Zn), the following of which are spread in all areas: As, Co, Fe, Hg, Ni, Pb, Zn and Cu. The average concentration of heavy metals in the soils of different regions, included within the province of High Zavolzhye, ranges between widely spread limits: from 4,74 to 14,99 mg/kg As, from 12,12 to 20,27 mg/kg Co, from 20,57 to 43,24 mg/kg Cu, from 1,0 to 1,51 mg/kg Hg, from 26,0 to 46,06 mg/kg Ni, from 5,88 to 15,12 mg/kg Pb, from 55,18 to 114,44 mg/kg Zn, from 30038,07 to 44894,54 mg/kg Fe. In local areas the As, Co, Cu, Ni, Zn, Pb elements content in the soil exceeds the established M.A.C. Heavy metal reserves in the 30 cm layer of the arable soils (from an estimation of 1 hectare), potentially accessible to plant roots, are in kilogrames/hectare: As. 14,709.48,118; Co. 37,451.65,067; Cu. 67,881.137,773; Hg. 3,09.4,847; Ni. 80,37.161,898; Pb. 18,875.46,721; Fe. 96422,2.145041,2. Based upon the areable area of all the administrative regions, included within High Zavolzhye province, the heavy metals stock in arable soil-cover reach: up to 14256,154 of As, 29443,377 of Co; 69903,626 of Cu; 2227,254 of Hg; 76630,585 of Ni; 18578,694 of Pb; 173373,168 of Zn and 74548684,54 of Fe tonnes. They form the initial link in the biochemical cycle of the above mentioned elements.