The aim of this study was to evaluate the content and stock of total organic carbon in the soil and aggregates of a Red-Yellow Ultisol under management systems-conventional tillage with disc plow, disc plow plus harrow, harrow and only no-tillage system in an experiment conducted over 23 years in the Zona da Mata region, Minas Gerais, Brazil. A remnant of native forest was used as reference. Soil samples were collected at different layers, to evaluate the total organic carbon based on soil mass, their storage in the soil depth and total organic carbon content in macro, meso and microaggregates. The results showed that in the long term, no-tillage system stored 1.5 Mg ha-1 total organic carbon in the surface layer. In the conventional management, the balance was negative, soil lost around 1.0 Mg ha-1 of organic carbon. There was no recovery of carbon in the deeper layers of all evaluated systems. The content of total organic carbon in aggregates varied with the size and form of adopted management, with higher accumulation in macroaggregates.
total organic carbon; no-tillage; conventional tillage; aggregates
