Analysis of Lead Adsorption in Oxisols and Evaluation of Its Phytoavailability

Abstract

-Adsorption reactions in the mobility and availability of lead (Pb) in soils and uptake by plants are important because of its potential for contamination of humans and animals. Considering the lack of information of this nature in variable charge soils, this paper aimed to study the chemical and physical properties of soils collected in five points the margin of a highway, analyze the reactions of these five soils and tomatoes (Lycopersicon esculentum) at different pH values and four concentrations of lead, applied in the form of nitrate, and to correlate the properties of the soil and the results obtained. We analyzed different chemical and physical properties of soils and the levels of lead, before and after 60 days to start the experiment. The soils under study were classified as medium texture and clayey and lead values found are within the range of natural levels in the soil. The interaction effects were only observed between the treatments containing higher doses of lead nitrate added and pH adjusted to 6.5. Samples of tomatoes were separated into aerial part and fruits and then analyzed for lead content. In tomato aerial part, the significant difference was only observed with the higher dose, whereas in the fruit Pb concentrations were below the detection limit.