Table 2. Soil variables used with their abbreviation, characteristics and unit of measurement.
| Soil variables | Abbreviation | Characteristics (Unit) |
|---|---|---|
| Soil organic carbon content | ORCDRC | NA (permille) |
| Soil organic carbon stock | Ocstha | NA (ton/ha) |
| Bulk density | BLDFIE | fine earth (kg/m3) |
| pH index measured in KCl solution | Phikcl | Relative acidity or alkalinity |
| pH index measured in water solution | Phihox | Relative acidity or alkalinity |
| Weight percentage of the silt particles | SLTppt | Particles about 0.0002–0.05 mm (percentage) |
| Cation Exchange Capacity of soil | CECSOL | NA (cmolc/kg) |
| Depth to bedrock | BDRICM | R horizon up to 200 cm (cm) |
| Weight percentage of the clay particles. | CLYPPT | Particles about <0.0002 mm (percentage) |
| Volumetric percentage of coarse fragments. | CRFVOL | Coarse fragments about >2 mm (percentage) |
*Note: NA: Not Applicable. Source: ISRIC—World Soil Information (39).