Oxidizable fraction of organic carbon in an argisol under different land use systems

Abstract

The objective of this study was to evaluate carbon input in labile and stable fractions in an ARGISOL of northwesternBrazil under different land use systems. Use systems being evaluated include: forest - MA (reference), agrosilvopasture – TCP (teak, cocoa and pasture); agroforest – TC (teak and cocoa); teak forest at 8 and 5 years – T8 and T5, and pasture - PA. In each system three furrows were made at depths of 0-5 cm, 5-10 cm and 10-20 cm. An area consisting of native vegetation (forest) adjacent to the experiment was sampled and used as control treatment. The use systems MA, T8 and T5 had higher levels of total organic carbon (COT) and the MA system had higher levels of labile carbon (CL) than the other systems, with the exception of TC at a depth of 10-20 cm. In the MA system, COT levels were higher in comparison to use systems TCP, TC and PA while CL levels were higher than the levels observed in use systems TCP and TC. In most cases being analyzed, CL levels were lower than COT levels, therefore this trait can be used as an indicator to assess anthropogenic changes relating to the maintenance or condition of soil organic matter.