| Site characteristics | NK1 | NK3 | FBT | MIN1 |
| Geographical coordinates | Lat: 05˚38'73''N, Length: 10˚38'899''E | Lat: 5˚37'902''N, Length: 10˚39'145''E | Lat: 5˚29'918''N, Length: 10˚37'354''E | Lat: 03˚17'9''N, Length: 11˚33'2''E |
| Land use/vegetation | Soil under fallow. It is a wooded savannah at 10 m from a gallery forest colonized by Hypparegna sp. vegetation, which are low grasses | Soil previously cultivated by maize (Zea mays). | Soil previously cultivated by maize (Zea mays) and beans (Phaseolus vulgaris); soil currently populated by herbaceous vegetation Bidem spilosa Mimosa | Bare ground in the equatorial forest |
| Soil mining - plough type - type of machine - fertilizer application | Under fallow | Machine | Ploughing | Uncultivated soil |
| Geomorphology | Flat basin. Topography of the neighbouring area is rugged and varies in altitude from 50 to 400 m | It is a bowl. | It is a bowl. | Area with a concave slope of about 3% to 4%. The surrounding vegetation is an equatorial forest zone with a herbaceous layer composed of Chromolaena odorata and cyperaceae |
| Relief | Altitude of 1145 m. | Altitude of 1 148m | Altitude of 1082 m | Altitude of 662 m |
| Erosion/altitude | No evidence of erosion | No evidence of erosion | No evidence of erosion | No evidence of erosion |
| Parent materials | Basalt | Basalt | Volcanic ash in pyroclastic deposits | Granite |
| Soil moisture | Aquic | Udic | Udic | Udic |
| Soil temperature | Isothermal | Isothermal | Isothermal | Isohyperthermal |
| Soil classification: IUSS working group WRB | Melani-Umbric Andosols (Dystric) | Melani-Umbric Andosols (Dystric) | / | Acri-Hyperdystric Ferralsol (Xanthic) |
| Soil classification: Soil survey staff | Typic Melanudands, medial over loamy skeletal, isothermic | Typic Melanudands, medial over loamy skeletal, isothermic | / | Kaolinitic clayey isohyperthermic Acrudox |