Assessment of Vanadium Content in Soils Under Equatorial Climate

Abstract

It is challenging to accurately analyze and monitor the environmental quality of soils globally because data on precise baseline concentrations are lacking. Colombia is a country where baseline data is practically missing. This study focused on the highly weathered soils of the Piedmont Llanero (hyperhumid equatorial environment). The baseline vanadium (V) concentration was assessed and the possible influence of agricultural land use was examined. The results showed clear variability in V concentrations across land uses. The V content in soils in the natural environment was 5.8–76.7 mg kg⁻¹ with a mean of 31.5 mg kg⁻¹ and in agricultural soils was 20.7–88.6 mg kg⁻¹ with a mean of 51.8 mg kg⁻¹. The overall average was 41.7 mg kg⁻¹ with a range of 5.8–88.6 mg kg⁻¹, which are widely scattered values. The V concentration was compared to the world average values and was within normal ranges versus other areas. The calculated reference value (RV) for V was 38.4 mg kg⁻¹. Based on the contamination factor, contamination was moderate (1.1) in the whole area. No contamination was detected when analyzed with I-geo (−0.6). These findings clearly suggest that V was moderately contaminating in cultivated soils, but posed no ecological risks in the study area. No simple relation was found between V concentrations and investigated litho- and pedogenic factors. This work contains valuable information for not only legislative purposes but also for soil quality RVs in a hyperhumid equatorial climate.