Background: Cadmium ( Cd) is one of the most toxic heavy metals and is considered non-essential for living organisms . This metal is easily absorbed by plants and transported to the animal and human food chain. Organic residuals used as fertilizers or amendments in agricultural lands are the main sources of Cd in soil. It is important to study uptake and translocation of Cd by plants grown in Cd-contaminated soils. The purpose of this greenhouse study was to investigate the impact of sewage sludge, municipal waste compost and cow manure on uptake and root to shoot translocation of Cd in alfalfa.

Materials and Methods: A completely randomized design with three treatments (sewage sludge, compost and cow manure applied at 25 Mg/ha) and three replicates was used. Alfalfa seedlings were harvested 60 days after planting and the uptake and translocation of Cd were measured in their shoot.

Results: Results indicated that the greatest Cd uptake by alfalfa shoot was obtained in the compost treatment. The percentage of Cd translocated to the shoots of alfalfa in compost treatment was greater compared to the other treatments. Application of cow manure significantly decreased uptake and translocation of Cd.

Conclusion: The results of this study reveal that the Cd source and plant species are important factors in evaluation of uptake and translocation of Cd to the edible parts of plants.