Table 2 Soil physical and biochemical characteristics (mean ± SE; n = 32 plots), measured in the Budongo Forest Reserve, Uganda, prior to the start of the nutrient addition experiment.
From: Nitrogen and potassium limit fine root growth in a humid Afrotropical forest
Site characteristics | Unit | Soil depth | |
|---|---|---|---|
0 − 10 cm | 10 − 30 cm | ||
Bulk density | g cm−3 | 1.2 ± 0.0 | 1.5 ± 0.0 |
Sand | % | 55 ± 2 | 55 ± 2 |
Silt | % | 27 ± 2 | 21 ± 1 |
Clay | % | 18 ± 0.8 | 24 ± 1 |
Soil pH (1:2.5 H2O) | 6.4 ± 0.0 | 6.1 ± 0.1 | |
Soil organic carbon | kg C m−2 | 4.0 ± 0.1 | 4.6 ± 0.2 |
Total nitrogen | kg N m−2 | 0.4 ± 0.0 | 0.6 ± 0.0 |
C:N ratio | 9.5 ± 0.1 | 8.0 ± 0.1 | |
Total phosphorus | mg P kg−1 | 660 ± 104 | 506 ± 124 |
Calcium | mg Ca kg−1 | 6254 ± 362 | 5205 ± 180 |
Potassium | mg K kg−1 | 120 ± 6 | 52 ± 7 |
Magnesium | mg Mg kg−1 | 1410 ± 87 | 787 ± 83 |
Base saturation | % | 98.2 ± 0.2 | 97.5 ± 1.0 |
Effective cation exchange capacity | mmol+ kg−1 | 149.2 ± 8.3 | 63.0 ± 4.1 |
