Lima, T.R., Nunes, D.D., Silva, J.M. da, Linhares, D.P., Mendes, A.M. and Silva, D.F.A. 2005. Soils natural fertility of Madeira-RO fluvial plain: a physic-chemistry analysis (CEC, m% E V%) of the stretch from Porto Velho-RO to Humaitá-AM. Sociedade & Natureza. 1, 1 (May 2005). DOI:https://doi.org/10.14393/SN-v1-2005-9722.