Cadmium Adsorption by Soils and Uptake by Plants as Affected by Soil Chemical Properties

Abstract
The quantity of Cd2+ adsorbed by soils from the northeastern USA was measured at a given equilibrium concentration (10−5M) of the metal in soil solution. This “retention capacity” was strongly related by a linear function to the exchangeable Ca2+ content of the soils. In addition, Cd2+ uptake by corn plants grown in these soils amended with 1‐µg Cd2+/g of soil was measured and found to be related to the retention capacity of the soil for Cd2+ by a curvilinear function. Although organic matter and clay in soil were able to limit Cd2+ uptake by the plants, the best soil indicators of Cd2+ availability were the retention capacity and exchangeable base (mainly Ca2+) content. The ability of exchangeable bases to account for most of the variability in Cd2+ adsorption by the soils as well as uptake by the plants is attributed to the important role of Cd2+‐Ca2+ exchange reactions in the soil.
Funding Information
  • Regional Res. Project (NE-96)