Table 5 Summary of stepwise multiple regression equations for metal concentrations in the grains of three crop species as function of soil total or extractable metal concentrations and soil properties.
Equation | r2 | radj2 | pvalue | |
|---|---|---|---|---|
Brassica juncea/Rape (n = 36) | Log10[grain] − (Cu)* = 0.304 + 0.146 Log10[total] − (Cu)** | 0.283 | 0.262 | 0.001 |
Log10[grain] − (Cd) = − 1.189 + 0.158Log10[EDTA] − (Cd) | 0.135 | 0.109 | 0.028 | |
Log10[grain] − (Mn) = 1.221 + 0.234 Log10[DTPA] − (Mn) | 0.306 | 0.286 | < 0.001 | |
Triticum aestivum/Wheat (n = 25) | Log10[grain] − (Cu) = 0.655 + 0.096Log10[total] − (Cu) | 0.408 | 0.382 | 0.001 |
Log10[grain] − (Cu) = 1.192 + 0.144Log10[total] − (Cu) − 0.318 Log10(AK) | 0.560 | 0.520 | < 0.001 | |
Log10[grain] − (Zn) = 1.686 + 0.061Log10[NH4OAC] − (Zn) | 0.285 | 0.254 | 0.006 | |
Log10[grain] − (Zn) = 1.338 + 0.046Log10[NH4OAC] − (Zn) + 0.559 Log10[total] − (Zn) | 0.415 | 0.362 | 0.003 | |
Log10[grain] − (Cd) = − 0.404 + 0.441Log10[DTPA] − (Cd) | 0.330 | 0.301 | 0.003 | |
Log10[grain] − (Cd) = 0.632 + 0.601Log10[DTPA] − (Cd) − 0.145pH | 0.563 | 0.524 | < 0.001 | |
Log10[grain] − (Mn) = 1.491 + 0.183Log10[NH4OAC] − (Mn) | 0.674 | 0.659 | < 0.001 | |
Log10[grain] − (Mn) = 1.644 + 0.273Log10[NH4OAC] − (Mn) − 0.167 Log10[DTPA] − (Mn) | 0.732 | 0.708 | < 0.001 | |
Oryza sativa/rice (n = 20) | Log10[grain] − (Cu) = 0.186 + 0.074 pH | 0.285 | 0.246 | 0.015 |
Log10[grain] − (Zn) = 1.745–0.199 Log10(AK) | 0.228 | 0.185 | 0.036 |
