DEGREEE OF CONTAMINATION BETWEEN VERTISOLS AND ENTISOLS IN AGRICULTURAL REGIONS OF GUANAJUATO (MEXICO)

PUY-ALQUIZA, M.J.; GARCÍA M.G; MIRANDA-AVILÉS, R. ; ZANOR, G.A.; SEGOVIANO-GARFIAS, J.J.N.

Congreso; ASABE annual international meeting; 2017

In the lastdecades, agricultural activities have exerted a great impact in the naturalresources all over the world. Nowadays, Mexico is suffering a great pressure inagricultural soils caused by the excessive use of fertilizers, compaction,salinity and irrigation with contaminated waters from deep wells. The purposeof this work was to evaluate the degree of contamination between Vertisols andEntisols (1.20 m deep) in agricultural zones of Guanajuato by usingcontamination indexes (Index of geoaccumulation, contamination factor and degreeof contamination) with respect to Earth?s crust as reference values. Four traceelements (Zn, Cu, Pb and As) were analyzed for total concentration by InductivelyCoupled Plasma Atomic Emission Spectroscopy (ICP-AES). Furthermore, pH,electric conductivity, clay, organic matter and Fe contents were determined inorder to establish properties-metal(loid)s relationships, supported bystatistical analyses. In the Vertisols, As showed a positive correlation with organicmatter while negative correlations were revealed between the four elements andelectric conductivity, and clay contents. Conversely, in the Entisols, the As levelsdisplayed lack of correlations with soil characteristics whereas Cu and Pbshowed positive associations with organic matter and clay percentages. Ingeneral, Fe contents strongly correlated with Zn, Cu andPb. The Vertisols resulted uncontaminated (mean Igeo<0) for Zn, Cu, Pb andAs with a dominant low factor and degree of contamination (Cdeg= 2.17).In contrast, the Entisols registered moderate to considerable degree ofcontamination for all the elements (Cdeg= 8.86). The higher amounts oftoxic elements in the Entisols suggest an accumulation from anthropogenicsources, governed probably by metal enriched parent materials transported frommining areas. Further investigation will explore the metal(oid)s mobility inorder to assess the capacity of these toxic elements to entry into the foodchains of the edaphic systems.