Table 3: Soil fertility and available content of heavy metals in the soil mixtures used in the experiment (after incubation).

Attribute Proportion of contaminated soil (%)EquationRegression coefficienta
0 255075100

pH CaCl2 0.98*
OM (g kg−1) 0.52*
P (mg kg) 0.52*
K (mmolc kg−1) 0.27*
Ca (mmolc kg−1) 0.80*
Mg (mmolc kg−1) 0.84*
H + Al (mmolc kg−1) 0.95*
CEC (mmolc kg−1)b 0.80*
SB (%)c 0.89*
S (mg kg−1) 0.83*
B (mg kg−1) 0.98*
Cu (mg kg−1) 0.87*
Fe (mg kg−1) 0.27*
Mn (mg kg−1) 0.99*
Zn (mg kg−1) 0.92*
Cd (mg kg−1) 0.91*
Cr (mg kg−1) 0.69*
Ni (mg kg−1) 0.89*
Pb (mg kg−1) 0.41*

Significant at (*).
bCation exchange capacity = Ca2+ + Mg2+ + K+ + H+ + Al3+.
cBase saturation = (Ca2+ + Mg2+ + K+ + Na+/CEC ) * 100.