Table 1.

Prediction equations calculated by stepwise multiple linear regressions (n = 60)^a.

Eq. No.	Prediction Eq.	R 2
2	Plant-Cd = 0.064 DGT-Cd - 0.008 pH - 0.015	0.95**
3	Plant-Cd = 0.183 soil solution-Cd – 0.005OC – 0.013 pH + 0.114	0.92**
4	Plant-Cd = 2.679 EDTA-Cd – 0.003 OC + 0.072	0.89**
5	Plant-Cd = 7.443 HAc-Cd – 0.014 pH – 0.004OC + 0.136	0.84**
6	Plant-Cd = 9.979 CaCl2-Cd – 0.006OC – 0.017 pH + 0.149	0.82**
7	Plant-Cd = 0.356 total-Cd - 0.034 pH - 0.005OC + 0.350	0.78*

*Correlation is significant at P < 0.05, **correlation is significant at P < 0.01. ^aFive soil properties, i.e., pH, OC, CEC, CaCO₃ and clay content, were used as inputs, and plant Cd concentrations were used as outputs. The significance level was P > 0.05 for CEC, CaCO₃, and clay content in each equation and P < 0.01 for pH and OC in each equation except for Eq. 2 (P < 0.05 for pH in Eq. 2).