TABLE 3.
Soil chemical data by depth. Values are means ± std. err. (n = 15).
| Property | Soil Depths (cm) | |||
| 0–15 | 15–30 | 30–60 | p-Value | |
| pH (paste) | 6.84 ± 0.17a | 7.14 ± 0.14b | 7.95 ± 0.06c | <0.0001 |
| Sand% | 40.6 ± 2.47 | 37.8 ± 2.51 | 25.7 ± 2.63 | 0.392 |
| Clay% | 26.7 ± 1.22b | 31.6 ± 1.09a | 34.3 ± 1.20a | 0.002 |
| Silt% | 32.7 ± 1.59 | 30.6 ± 1.84 | 30.1 ± 1.93 | 0.553 |
| Electrical conductivity (dS m–1) | 0.44 ± 0.06 | 0.72 ± 0.27 | 1.67 ± 0.75 | 0.300 |
| Bulk density (g cm–1) | 1.16 ± 0.04b | 1.26 ± 0.0.4ab | 1.36 ± 0.03a | 0.004 |
| Total carbon (C; Mg ha–1) | 35.7 ± 2.29b | 28.2 ± 3.25c | 86.8 ± 3.81a | <0.0001 |
| Organic C (Mg ha–1) | 30.9 ± 2.63a | 16.5 ± 1.13b | 26.0 ± 2.71a | <0.0001 |
| Org C/Total C | 0.87 ± 0.04a | 0.68 ± 0.07a | 0.37 ± 0.04b | <0.0001 |
| Total nitrogen (N, Mg ha–1) | 3.27 ± 0.20a | 2.14 ± 0.10b | 3.44 ± 0.23a | <0.0001 |
| CNratio | 0.09 ± 0.01a | 0.09 ± 0.01a | 0.04 ± 0.01b | <0.0001 |
| Nitrate (kg ha–1) | 3.04 ± 0.45 | 2.05 ± 0.44 | 2.77 ± 0.67 | 0.162 |
| Total phosphorus (P, kg ha–1) | 911 ± 37.6b | 911 ± 44.3b | 2,136 ± 98.4a | <0.0001 |
| Organic P (kg ha–1) | 449 ± 30.0 | 382 ± 55.5 | 479 ± 48.0 | 0.179 |
| Olsen P (kg ha–1) | 9.94.1.69 a | 3.40 ± 0.56b | 8.02 ± 2.75ab | 0.006 |
| Meh P (kg ha–1) | 38.3 ± 4.3a | 13.2 ± 2.6b | 32.5 ± 10.1ab | 0.007 |
| CaCl2-P (kg ha–1) | 5.47 ± 0.34b | 4.48 ± 0.14b | 9.86 ± 0.65a | <0.0001 |
| Meh calcium (Ca, kg ha–1) | 5,259 ± 1,568c | 12,569 ± 3,750b | 42,026 ± 5,139a | <0.0001 |
| AACa (kg ha–1) | 3,420 ± 456c | 5,266 ± 498b | 13,484 ± 457a | <0.0001 |
| Meh magnesium (Mg, kg ha–1) | 901 ± 82.6c | 1,757 ± 191b | 6,599 ± 732a | <0.0001 |
| AAMg (kg ha–1) | 729 ± 54.3c | 1,355 ± 136b | 4,313 ± 452a | <0.0001 |
| Meh aluminum (Al, kg ha–1) | 948 ± 115a | 709 ± 167a | 102 ± 69b | <0.0001 |
| Meh iron (Fe, kg ha–1) | 182 ± 17.3 | 126 ± 15.9 | 183 ± 25.4 | 0.078 |
| DTPA Fe (kg ha–1) | 75.1 ± 11.7a | 32.3 ± 4.31b | 35.5 ± 3.31b | 0.003 |
| Meh manganese (Mn, kg ha–1) | 147 ± 11.4a | 92.1 ± 10.0b | 212 ± 26.7a | 0.002 |
| DTPA Mn (kg ha–1) | 38.1 ± 4.28a | 21.5 ± 0.14b | 7.95 ± 0.06c | 0.001 |
| DTPA potassium (K, kg ha–1) | 457 ± 37.1a | 277 ± 40.7b | 604 ± 79.9a | <0.0001 |
| DTPA zinc (kg ha–1) | 4.53 ± 1.59a | 1.20 ± 0.32b | 2.40 ± 0.97ab | 0.003 |
| DTPA copper (Cu, kg ha–1) | 2.29 ± 0.25b | 2.65 ± 0.17b | 5.79 ± 0.42a | <0.0001 |
| CaCl2 SO4-S (kg ha–1) | 13.1 ± 2.96 | 92.8 ± 81.8 | 781 ± 466 | 0.089 |
Different letters within each row and p-values in bold indicate statistically significant differences (ANOVA followed by Tukey HSD; α = 0.5). AA, ammonium acetate extraction; DTPA, diethylenetriaminepentaacetic acid extraction; Meh, Mehlich extraction. Data were adapted from Cade-Menun et al. (2017).