Determination of the concentration of heavy metals in soils of the Quero-Tungurahua canton. Case Study

Abstract

Introduction: The Quero canton located in the province of Tungurahua, eminently agricultural and livestock, has suffered a reduction in crop yields in recent years. Objectives: The objective of the research was to determine the quality of soil for agricultural use to ensure food quality. Methodology: it began with the determination of the sampling points considering the facilities provided for access to the land, proceeded to take the soil sample, subsequent treatment, physical-chemical and chemical analysis, and finally interpretation. Results: the results indicate a pH variation of 4.30 -7.18 (ranging from extremely acidic to neutral), an electrical conductivity between 39.40 and 123.25 uS/cm (negligible salinity values), a bulk density between 1.02-1.20 g/ml, real density 2.52-2.85 g/ml, OM content between 1.42-2.87%, the texture identified was mostly sandy-loam. The N content ranged from 100-1100 mg/kg, the P from 304.33-316.33 mg/kg, the K from 411.68-1780.35 mg/kg, the Ca from 143.44 mg/kg to 541.81 mg/kg, the Mn from 77.58 mg/kg to 159.55 mg/kg, and the Zn from 9.75 mg/kg to 20.71 mg/kg. The results of the heavy metal analyses Cd, Pb and Hg indicated values below the detection limit of the equipment (0.25 mg/kg), the Se content varied between 0.02 and 0.09, while As presented a variation between the detection limit 0.25 mg/kg and 0.84 0.25 mg/kg; the Cd, Pb, Se and As complied with the reference values of the Ecuadorian Regulations, so it can be concluded that there is no risk of contamination by heavy metals in the products grown in these soils. Conclusions: The heavy metal analysis values of Cd, Pb, Se and As were lower than the reference value established by current Ecuadorian regulations, which shows that there is no contamination by heavy metals in these soils. General study area: agriculture. Specific area of study: sustainable management of natural resources. Item Type: Original