| Variable | Depth | Value (range) | Units | Ref year | Estimated? | Baseline? |
|---|---|---|---|---|---|---|
| clay content | 0 – 20 Centimetres | 260 | gram per kilogram | 1971 | ||
| clay content | 20 – 90 Centimetres | 460 | gram per kilogram | 1971 | ||
| clay content | 90 Centimetres | 270 | gram per kilogram | 1971 | ||
| silt content | 0 – 20 Centimetres | 80 | gram per kilogram | 1971 | ||
| silt content | 20 – 90 Centimetres | 70 | gram per kilogram | 1971 | ||
| silt content | 90 Centimetres | 80 | gram per kilogram | 1971 | ||
| find sand content | 0 – 20 Centimetres | 300 | gram per kilogram | 1971 | ||
| find sand content | 20 – 90 Centimetres | 200 | gram per kilogram | 1971 | ||
| find sand content | 90 Centimetres | 300 | gram per kilogram | 1971 | ||
| course sand content | 0 – 20 Centimetres | 350 | gram per kilogram | 1971 | ||
| course sand content | 20 – 90 Centimetres | 270 | gram per kilogram | 1971 | ||
| course sand content | 90 Centimetres | 340 | gram per kilogram | 1971 | ||
| soil organic carbon | 0 – 20 Centimetres | 10.8 | gram per kilogram | 1971 | ||
| total soil nitrogen | 0 – 20 Centimetres | 1.07 | gram per kilogram | 1971 | ||
| soil pH | 0 – 20 Centimetres | 5.5 | pH water | 1971 | ||
| exchangeable calcium | 0 – 20 Centimetres | 3.2 | cmolc kg−1 | 1971 | ||
| exchangeable magnesium | 0 – 20 Centimetres | 0.53 | cmolc kg−1 | 1971 | ||
| exchangeable potassium | 0 – 20 Centimetres | 0.14 | cmolc kg−1 | 1971 | ||
| exchangeable sodium | 0 – 20 Centimetres | 0.02 | cmolc kg−1 | 1970 | ||
| cation exchange capacity | 0 – 20 Centimetres | 5.8 | cmolc kg−1 | 1971 |
| Variable | Time period | Value (range) | Units |
|---|---|---|---|
| air temperature | 25.9 | degree Celsius | |
| precipitation | 1400 | millimeter |
| Crop | Years grown |
|---|---|
| maize | |
| bare fallow | |
| soybeans | |
| ground nuts | |
| cow peas |
| Variable | Material | Units | Frequency | Scale | Comment |
|---|---|---|---|---|---|
| grain yield trait | All crops | kg/ha | annually | ||
| soil organic carbon | Soil | g/kg | 1971, 1974, 1975, 1979, 1981, 1993 |