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(T/MF139) Influence of Polluting Sources on the Quality of the Agricultural Soils in La Rioja (Spain). Alvarez, A.1, Andrades, M.S.2, Martinez, E.2, Jimenez, R.1, Carral, P.1, Alonso, J.I.2, 1 2 ABSTRACT- It was determined the total contents and bioavailability of heavy metals: Pb, Cu, Zn, Ni and Cd in superficial samples of the subject soils. These soils, belong to parcels located at the borders of highways with different density of light traffic and are dedicated to cultivation fruit. The studied soils are characterized by: moderately basic pHs, high contents in carbonates, fundamentally loamy textures and variable contents of organic matter, very high in some cases, for soils dedicated to the agriculture. The Data have been processed statistically and their correlation matrix determined. From this the following considerations have been derived: They are two possible sources of contribution of metals, one of them includes the Cu, Ni, Zn, and Cd, the other one affects the Pb. There is a correlation between the total contents and bioavailability for Cu, Ni, and Zn, while there is not for the Pb; levels of availabilities of Cd has not been detected. It has been verified that the particular forms which are more commonly available in this soil solutions, for the studied samples and under these physical-chemical condidtions, are for the Cu, the changeables forms associated to the clay minerals; for the Zn, the changeable forms assocaited to the carbonates. The Pb forms more easily assimilable are associated to the organic matter and to the carbonates without showing any particular preference. In spite of not finding high levels of heavy metals weighed in soils, the contents of Cu and Zn in leaf and bark they are very high, due to the biocide treatments received by the fruit-bearing trees. Key words: heavy metals, soils, La Rioja |
