Resumen

BIANCHI, Silmara R.; MIYAZAWA, Mario; OLIVEIRA, Edson L. de  y  PAVAN, Marcos Antonio. Relationship between the mass of organic matter and carbon in soil. Braz. arch. biol. technol. [online]. 2008, vol.51, n.2, pp. 263-269. ISSN 1516-8913.  http://dx.doi.org/10.1590/S1516-89132008000200005.

The quantity of soil organic matter (SOM) was estimated through the determination of soil organic carbon (SOC) times a factor, which assumes that 58% of the SOM was formed by carbon. A number of soil samples with wide range of SOC content collected in the state of Paraná, Brazil were evaluated in the laboratory. SOC was measured by Walkley-Black method and the total SOM by loss on ignition. The SOC was positively correlated with SOM. The SOM/SOC ratio varied from 1.91 to 5.08 for the soils. It shows that Brazilian SOM has greater oxidation degree. Although, the SOM and SOC decreased with soil depth the SOM/SOC ratio increased. It showed that SOM in the subsoil contained more oxygen but less carbon than the SOM in the upper soil surface. The CEC/SOC also increased with depth indicating that the functional groups of the SOM increased per unity of carbon.

Palabras llave : Organic carbon; tropical soils; soil analysis.