Table 2 Chemical characteristics of the soil samples
| Â | Â | Hiyoriyama | Amamiya |
|---|---|---|---|
pH | - | 5.9 | 6.1 |
Electrical conductivity | dS/m | 0.23 | 0.02 |
Total organic carbon | g/kg | 3 | 2.4 |
Total nitrogen | g/kg | 0.2 | 0.2 |
Ammonium nitrogen (NH3) | mg/kg | 19.9 | 15.9 |
Nitrate nitrogen (NO\(_{3}^{-}\)) | mg/kg | 6.2 | 84.5 |
Nitrite nitrogen (NO\(_{2}^{-}\)) | mg/kg | <0.05 | <0.05 |
Effective phosphate (PO\(_{4}^{3-}\)) | mg/kg | 12 | 40 |
Exchangeable K + | cmol(+)/kg | 0.34 | 0.36 |
Exchangeable Ca 2+ | cmol(+)/kg | 6.19 | 4.32 |
Exchangeable Mg 2+ | cmol(+)/kg | 0.44 | 0.94 |
Exchangeable Na + | cmol(+)/kg | 0.42 | 0.10 |
Exchangeable Mn 2+ | mg/kg | 1.52 | 3.07 |
Available iron (Fe) | mg/kg | 142 | 10.4 |
Cl − | mg/kg | 15.7 | 12.4 |
Sulfate (SO\(_{4}^{2-}\)) | mg/kg | 379 | 2 |
Cd a | mg/l | <0.001 | <0.001 |
Cr(VI) a | mg/l | <0.005 | <0.005 |
Total mercury (Hg) a | mg/l | <0.0005 | <0.0005 |
Alkyl mercury (Hg) a | mg/l | <0.0005 | <0.0005 |
Pb a | mg/l | <0.004 | <0.004 |
As a | mg/l | <0.001 | 0.001 |
B a | mg/l | <0.1 | <0.1 |
Cd b | mg/kg | <15 | <15 |
Cr(VI) b | mg/kg | <25 | <25 |
Hg b | mg/kg | <1.5 | <1.5 |
Pb b | mg/kg | <15 | <15 |
As b | mg/kg | <15 | <15 |
B b | mg/kg | <400 | <400 |
Cu b | mg/kg | <10 | <10 |
Zn b | mg/kg | 100 | 49 |
Ni b | mg/kg | <30 | <30 |