Evaluation of the content of heavy metals in agricultural soils of the district of Jesús – Cajamarca

Abstract

The main objective of the research was to know the content of heavy metals Pb, Cd, Cr, Cu and Zn, existing in agricultural soils of the La Bendiza Caserío in the district of Jesús, Province of Cajamarca. Also, the edaphic parameters were evaluated: texture, pH, electrical conductivity, organic matter and cation exchange capacity (CEC). Three soils dedicated to intensive cabbage cultivation were chosen, considering the high consumption of pesticides and chemical fertilizers, especially the former due to their impact on human health. From each field, 10 simple samples were taken to form a composite sample, of which, after mixing them, 1 kg was taken for corresponding analysis. The results of the analyzes were evaluated and interpreted in accordance with current national regulations (Reglamento de Clasificación de Suelos por su Capacidad de Uso Mayor: D.S. N° 005- 2022-MIDAGRI), ECA Suelo (D.S. 002-2013-MINAM) and the Canadian Standard: Canadian Environmental Quality Guidelines (CEQG) 2007, for the parameters that do not appear in the national regulations, such as copper and zinc. All the soils evaluated showed a light texture (sandy loam), while the average results obtained for the edaphic parameters were 7.68 for pH, electrical conductivity: 0.44 dS/m, organic matter: 1.36% and CEC: 10.73 meq/100 g of soil. The maximum concentrations of heavy metals found for the three fields was: lead (4.31 ppm), cadmium (3.84 ppm), chromium (0.34 ppm), copper (12.57 ppm), and zinc (61.65 ppm), values that when compared with the ECA Suelo, indicate that the only metal which had surpassed this Cadmium standard; however, the presence of other heavy metals, although in lower concentrations due to their non-biodegradable and bioaccumulative condition, represent a risk to the health of consumers.