Interestingly, we found a linear negative correlation (p b 0.01) between L. sativa root elongation and metal CaCl2
-extractability (vegetated sites: r = −0.77 and −0.84 for Pb and Zn, respectively; non-vegetated sites: r = −0.70 and −0.85 for Pb and Zn, respectively), supporting the potential use of the root elongation bioassay for the assessment of soil metal bioavailability in metal stabilization processes under field conditions (Galende et al., 2014).