Effects of soil polluted by cadmium and lead on production and quality of pepper (Capsicum annuum L.) and radish (Raphanus sativus L.)

A pot experiment was designed and chemical analysis of the vegetables was used to investigate the effects of heavy metal pollution on production and quality of vegetables. The soil tested was a grey chao soil (loamy) derived from Yangze River alluvial. Results indicated that for pepper grown on cadmium (Cd) and lead (Pb) polluted soil, the production was decreased, together with the reduction of the contents of vitamin C and sugar. The effects of combination treatment, Cd treatment and Pb treatment dropped successively under the concentrations tested; heavy metals influenced the biomass of pepper. Combination pollution by heavy metals reduced biomass, and the similar variation was observed to Cd treatments, while the Pb treatment increased pepper production to some extent. The biological mass of radish decreased by Cd treatment and increased by Pb treatment. Cd and Pb could decrease the contents of vitamin C remarkably in radish roots, and the influences of Cd was more significant than those of Pb. Pollution of Cd or Pb solely in the soil could increase sugar content obviously. However, Cd and Pb combination pollution could depress the accumulation of saccharide in radish root. Pb and Cd contents and distribution in pepper and radish tissues varied with the Pb and Cd addition levels. Generally, the contents of Cd and Pb in vegetable tissues increased with the addition quantities, and Cd moved more easily onto the up-ground parts but Pb accumulated in the roots of the plants.