| Abstrakt: |
Făgăraş Depression soil cover consists of a mosaic of soils where are prevalent Protisols represented by Fluvisols (39.2%), Luvisols represented by Luvisols and Haplic Luvisols (38.8%), Cambisols represented by Distric Cambisols and Eutric Cambisols (12.5%) and Hydrisols represented by Gleysols, Stagnosols and Histosols (7.5%). Făgăraş Depression soils, predominantly acid, with low content of humus and total nitrogen and a poor supply with phosphorus and potassium mobile forms present total contents of Cd, Co, Cr and Cu lower than normal contents values in soils. This are around the average values existing in the world soils, except Cr, that has a lower average value with 34mg ⋅ kg¹ than the world soils average. Distribution of heavy metal content values is normal. Frequency histograms are symmetrical and platicurtice, except copper, that has a strong asymmetry of left and leptocurtice shaped curve. Abundance of Cd in Făgăraş Depression is upper the lithospheric and pedospheric abundance of this element, while Cr and Cu abundance is below of the two geogenic types of abundance. Co abundance is below the lithospheric abundance, but higher than pedospheric once. Area distribution of the four heavy metals showed zones with concentrations higher than normal background of the whole territory, but without exceeding normal levels. Inverse proportionally relationships between pH and heavy metal content, statistically assured for Cd and Co; direct proportionality relationship, statistically assured between Cd and humus on the one hand, and between total N and mobile potassium, on the other hand; direct proportionality, statistically assured between Cu and N total and finally, close relationships of direct proportionality, statistically assured between Cd, Co and Cr were established. Copper has shown direct correlation, statistically assured, only with chromium. Origin of heavy metals is predominantly geogenic, namely, the minerals and the crystalline rocks of the northern versant of the Făgăraş Mountains. Industrial units present in this area did not influence the content of heavy metals in soils of Făgăraş Depression territory. [ABSTRACT FROM AUTHOR] |
