TABLE 2.

Effects of different treatments on Cd fractions (Tukey’s HSD test) ^a

Compartment	Bulk soil			Rhizosphere
Treatment	CK	Low	High	CK	Low	High
Water-soluble Cd (mg/kg)	0.022 ± 0.001a	0.022 ± 0.001a	0.022 ± 0.000a	0.024 ± 0.000a	0.023 ± 0.000a	0.022 ± 0.003a
Exchangeable Cd (mg/kg)	0.31 ± 0.03a	0.26 ± 0.12a	0.24 ± 0.03a	0.36 ± 0.11a	0.31 ± 0.13a	0.40 ± 0.13a
Carbonate bound Cd (mg/kg)	0.19 ± 0.03ab	0.27 ± 0.15b	0.36 ± 0.03a	0.19 ± 0.01b	0.21 ± 0.08b	0.21 ± 0.03b
Iron-manganese oxide bound Cd (mg/kg)	0.25 ± 0.02a	0.32 ± 0.13a	0.39 ± 0.05a	0.25 ± 0.00a	0.36 ± 0.10a	0.36 ± 0.08a
Organic bound Cd (mg/kg)	0.06 ± 0.00ab	0.06 ± 0.01ab	0.07 ± 0.01a	0.06 ± 0.00b	0.06 ± 0.01ab	0.06 ± 0.01ab
Residual Cd (mg/kg)	0.85 ± 0.08a	0.85 ± 0.13a	0.90 ± 0.12a	0.73 ± 0.10a	0.79 ± 0.11a	0.64 ± 0.40a
Total Cd (mg/kg)	1.67 ± 0.16a	1.69 ± 0.07a	1.70 ± 0.17a	1.66 ± 0.10a	1.75 ± 0.34a	1.67 ± 0.24a

^a Different letters mean significant differences between samples within rows (P < 0.05).