Effects of Zeolite Application on Cadmium Toxicity, Growth, Nodulation and Chemical Composition of Soybean

Cadmium is a toxic element which in low concentration negatively affects the soil quality. Wide areas of earth is polluted by heavy metals which will not be degraded by biotic process and might be entered to surface and/or underground water resources and food chain by planting and consequently expose hazards to human and animals. In recent years natural amendments, such as zeolite, have been widely used for fixing and decreasing heavy metals availability. This technique is chip, clean and quick compared to others. In the present study the effect of zeolite on the tolerance of soybean (Glycine max L.) was evaluated. Treatments consisted of factorial combination of 3 levels of zeolite (0, 2 and 5 g kg-1) and 3 levels of Cadmium (0, 10 and 50 mg kg-1) with 3 replications in a completely randomized design (CRD). Cadmium application decreased shoot and root dry weight and its concentration in plant parts was increased. Moreover, cadmium application decreased number and dry weight of nodules, and N, P, K, Fe, Zn, Cu and Mn concentrations. On the other hand, zeolite application increased number and dry weight of nodules; however, its application decreased K, Cu, and Mn concentrations in plant parts.