Cadmium phytoextraction with mulberry grass (Solanum nigrum L.) in soils grown with cocoa (Theobroma cacao L.)

Abstract

An important step towards a restoration of cadmium-contaminated soils (Cd) is the use of phytoextraction, using plants such as blackberry (Solanum nigrum L.), a species reported as hyperaccumulating, capable of tolerating and developing in soils with high concentrations of Cd, which can be considered an alternative of interest for cocoa growers (Theobroma cacao L.). With the purpose of facing the restriction for the commercialization that generates this element, due to the norms of the commerce of grain, with high contents of Cd and the implications that represents in the human health, in addition, of the great number of families whose main sustenance comes from this alternative, the response of S. nigrum to three concentrations of Cd in the soil, T1: 0, T2: 5, T3: 10 mg/kg was evaluated. It was evidenced as S. nigrum L. may be of interest for phytoextraction processes of this metal, since it is a fast growing plant, with low environmental demands and high acclimatization capacity. In this study a high correlation was found between the cadmium contents in soil and its accumulation in S. nigrum L., it was also found that the increase of cadmium in the edaphic medium favors the growth of this plant, increases the leaf area, enlarges the root biomass (r2 = 0.74) as well as stem and leaves in a significant way.