Reference soil Brazil 04: 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 BR004: Ferralsols
Brief field description: Very deep, well drained, dusky red clay soil derived from basic rock; weakly structured. High bio-activity: many antholes throughout the profile. Charcoal particles of 1-3 cm diameter throughout the profile. Silt fraction is considered to be pseudo-silt. *) Brazilian classification: Latossolo Roxo eutrofico. Reference soil BR 04 is comparable to soil profile No. 1360.