Abstract

MENDOZA-ESCALONA, Betty et al. Concentration of Heavy Metals in Soils Under Different Tillage Systems. TecnoL. [online]. 2021, vol.24, n.51, pp.4-15.  Epub Aug 27, 2021. ISSN 0123-7799.  https://doi.org/10.22430/22565337.1738.

Heavy metals are mineral elements whose accumulation in soils, water, and vegetal tissues constitutes a public health risk. High concentrations of these elements are associated with cancer and kidney and liver diseases. The accumulation of such metals is the consequence of industrial activities, but also agricultural production due to the excessive use of agrochemicals. Therefore, this study assessed the heavy metals contamination risk in Turen, in the northwest of Venezuela. Cd, Cu, Co, Zn, Fe, Mn, Ni, As, and Se were found in soils under two tillage systems (conventional and direct sowing) at two physiographic positions: high and low napa by X- ray fluorescence. The samples were taken at two depths, i.e., 0-10 and 10-20 cm, with nine samples per position in each tillage system. The results show that the content of Co, Cu, Ni, Cd, and Zn was higher in direct sowing due to the extended use of phosphate fertilizers. The greatest accumulation was observed at the low napa, which is associated with higher clay content and cation exchange capacity. The values of Co, Cu, and Cd were higher than the maximum allowable levels in most international environmental regulations. The accumulation of heavy metals in Turén soils, both in the conventional tillage system and in the direct sowing system, are the result of the continuous use of agrochemicals, in particular phosphate fertilization, so it is recommended to reduce the use of agrochemicals, in addition to carrying out bioremediation actions to eliminate them from the soil and avoid long-term contamination problems and health problems associated with their presence in soils and waters.

Keywords : Soil contamination; environmental impact; agricultural soils; soil measurements.

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