Effect of different soil pH on cadmium uptake by the plants

Cadmium is one of the toxic heavy metals which, getting in the nutrition chain through the soil-plant system, is capable of causing harm to human health. The objective of the trial was to study the effect of cadmium load in the soil-plant system. In pot experiments carried out under greenhouse conditions, effect of increasing Cd load on different crop plants (lettuce, maize) was studied. Literature data inform on the decisive role of soil reaction in mobility of cadmium in the soil. The answer was looked for the question of the effect of cadmium treatments at uniform rates on Cd uptake by plants on two soils quite different from each other in pH value. It may be concluded that increasing Cd load can result in the decrease of biomass production of maize and lettuce, but significant differences were obtained only on very acid SN soil. The concentration of Cd in plants increased on both soils as a consequence of growing Cd treatment rates. In corresponding treatments the Cd levels in lettuce and maize plants grown on very acid SE soil were several times higher than in case of plants on the KE soil. Obtained results confirm that Cd mobility on acid soil may be much higher what is clearly reflected in cadmium uptake by plants. On acid soils the cadmium uptake by plants is more intensive, therefore this toxic element is more likely to get in the nutrition chain. Considerable differences in Cd uptake can be detected among the plant species. On the same soil at the same rate of cadmium treatment. Cd level in lettuce plants was by several times higher than in maize. The lettuce plants can accumulate cadmium in the leaves at high concentrations without any visible symptoms. In the experiments no toxicity was observed on test plants.