Abstract

LOSS, Arcângelo et al. Total and oxidizable organic carbon in aggregates of an udult fertilized with pig manure. Cienc. suelo [online]. 2020, vol.38, n.1, pp.12-20. ISSN 1850-2067.

The objective of this study was to evaluate the total organic carbon (TOC) and carbon contents of the oxidizable fractions in biogenic and physicogenic aggregates in areas with pig slurry (PS) and deep litter (DL). After 10 years of use of pig manure (PM) in a crop succession with black oat/maize, undisturbed soil samples were collected in the 0-5 and 5-10 cm layers, in the treatments without PM (control) application, with application of PS and DL at a dose equivalent to one and two times the N recommended for maize and black oat, respectively. The aggregates were separated according to the biogenic and physicogenic formation pathway. Then, these aggregates were separated into macro, meso and microaggregates. In these aggregates the TOC was determined in the macro, meso and microaggregates and only in the macroaggregates for the C of the oxidizable fractions (fractions F1, F2, F3 and F4). Application of PS increases the TOC contents in the microaggregates while the DL increases TOC in macroaggregates. The use of DL for a long time increases the labile carbon (F1) and recalcitrant carbon (F4) in comparison to PS and control. Oxidizable carbon fractions showed differences between biogenic and physicogenic aggregates, being greater in the biogenic aggregates.

Keywords : pig slurry; deep litter; biogenic aggregates; physicogenic aggregates.

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