Effect of Rock Phosphate on Zn and Fe Bioavailability and Accumulation by Salix smithiana in Heavily Contaminated SoilS. Vondrackova, P. Tlustos and J. SzakovaE3S Web of Conferences, 1 (2013) 15004DOI: https://doi.org/10.1051/e3sconf/20130115004