Reference soil Indonesia 28: Ferralsol
Ferralsols occur in tropical and subtropical regions of the world, mainly on old and stable land surfaces.
Characteristics
Soils having a ferralic horizon (strongly weathered horizon with low-activity clays and very low amounts of weatherable minerals) between 25 and 200 cm from the soil surface. They lack a nitic horizon (a horizon with strongly developed, nut-shaped structure) and do not have a layer which fulfils the requirements of an argic horizon and which has, in the upper 30 cm, 10 percent or more water-dispersible clay.
Reference soil ID028: Ferralsols
LOCATION: The Indonesian monolith number is Sumut02. ADDITIONAL NOTES ON PROFILE DESCRIPTION: Charcoal fragments are present in the first 30cm of the profile. High biological activity, termite nests throughout the profile, in the topsoil many worms. Penetrometer reading: about 1 kg/cm2 in all horizons. There are only slight differences between the BA, Bw1 and Bw2 horizons, they could be considered as one B horizon. The transition from Ap to BA has frequent hoe marks.