Table 1.
Soil properties of samples from different land uses.
| Land Use Type | Parameter | pH | OC | CEC | Soil/Sediment Texture | Mn | Fe | ||
|---|---|---|---|---|---|---|---|---|---|
| (%) | (cmol·kg−1) | Clay (%) | Silt (%) | Sand (%) | (µg·g−1) | (%) | |||
| Red River (n = 9) | Average | 6.87 | 0.99 | 12.8 | 14.8 | 48.1 | 37.0 | 939 | 1.84 |
| Max | 7.21 | 1.25 | 15.8 | 21.7 | 65.2 | 74.3 | 1495 | 1.78 | |
| Min | 6.51 | 0.62 | 7.8 | 5.5 | 18.1 | 14.1 | 513 | 2.02 | |
| SD | 0.23 | 0.23 | 2.7 | 6.4 | 16.0 | 21.2 | 336 | 0.07 | |
| Shrimp farm (n = 6) | Average | 6.74 | 1.45 | 12.8 | 19.3 | 29.8 | 50.8 | 516 | 1.82 |
| Max | 7.03 | 2.83 | 16.0 | 26.2 | 44.4 | 68.5 | 906 | 1.76 | |
| Min | 6.52 | 0.69 | 8.2 | 10.4 | 21.1 | 29.4 | 204 | 1.91 | |
| SD | 0.19 | 0.77 | 2.9 | 5.2 | 8.4 | 13.2 | 285 | 0.04 | |
| Clam farm (n = 6) | Average | 6.89 | 0.56 | 6.1 | 5.6 | 16.3 | 78.1 | 692 | 1.55 |
| Max | 7.02 | 0.94 | 9.0 | 7.6 | 21.2 | 85.2 | 845 | 1.31 | |
| Min | 6.75 | 0.23 | 3.8 | 3.9 | 10.1 | 71.2 | 469 | 1.76 | |
| SD | 0.11 | 0.25 | 1.8 | 1.5 | 4.0 | 5.2 | 145 | 0.21 | |
| Mangrove forest (n = 14) | Average | 6.87 | 1.09 | 11.6 | 16.5 | 39.3 | 44.2 | 995 | 1.82 |
| Max | 7.03 | 2.64 | 20.2 | 30.3 | 60.8 | 74.3 | 2032 | 1.76 | |
| Min | 6.53 | 0.70 | 7.0 | 5.6 | 20.1 | 15.0 | 320 | 1.91 | |
| SD | 0.14 | 0.66 | 3.3 | 7.3 | 10.1 | 16.2 | 501 | 0.04 | |
| Paddy field (n = 32) | Average | 6.73 | 1.66 | 12.2 | 24.6 | 54.2 | 22.9 | 772 | 1.79 |
| Max | 6.98 | 2.59 | 19.7 | 56.5 | 65.8 | 76.2 | 2569 | 1.48 | |
| Min | 6.20 | 1.18 | 8.4 | 18.7 | 23.8 | 9.5 | 189 | 2.76 | |
| SD | 0.23 | 0.39 | 2.8 | 6.7 | 8.4 | 13.0 | 556 | 0.20 | |
| All samples (n = 67) | Average | 6.80 | 1.33 | 11.7 | 19.4 | 44.7 | 36.7 | 811 | 1.79 |
| Max | 7.21 | 7.21 | 20.2 | 56.5 | 65.8 | 85.2 | 2569 | 1.31 | |
| Min | 6.20 | 0.23 | 3.8 | 3.9 | 10.1 | 9.5 | 189 | 2.76 | |
| SD | 0.21 | 0.59 | 3.3 | 8.5 | 15.3 | 21.7 | 481 | 0.17 | |
OC, organic carbon content; CEC, cation exchange capacity; SD: standard deviation.