SOIL GENESIS AND DYNAMICS IN EQUATORIAL A REAS

The soil genesis in the equatorial areas is greatly controlled by the biological activity. The ferrallitic soil profiles depend on the biolo gical cycling of the elements that acts on the mineral-solution reacti ons. Most of the secondary minerals suffer a permanent disequilibrium by preciptation-dissolution, and reflect the local physico-chemical co nditions. The podzols develop when the organo-metallic compounds forme d in the topsoil are leached out; of the system before their microbial degradation. This depends on the water dynamics in the system.