Abstract

SILVA RODRIGUES PINTO, Luiz Alberto et al. Evolution and accumulation of C-CO₂ in biogenic and physiogenic aggregates of different agroecological management systems. Acta Agron. [online]. 2018, vol.67, n.4, pp.494-500. ISSN 0120-2812.  https://doi.org/10.15446/acag.v67n4.67923.

Determination of mineralizable carbon (C) is based on the evolution of C-CO2, reflecting the activity of soil biota in soil organic matter (SOM) decomposition, and can be used as a testing parameter in agroecological production systems. The objective of the present work was to quantify mineralizable C in aggregates of different biogenic and physiogenic formation pathways in agroecological management systems in the city of Seropédica, state of Rio de Janeiro. Five sampling areas were selected: (1) 10-year agroforestry system (AFS), (2) 15-year full sun coffee (C-SUN), (3) 15-year shaded coffee (C-SHA), (4) 10-year Flemingia macrophylla (FLE), and (5) 6-year no-till planting system with corn and eggplant (NT) in Red-Yellow Argisol in Seropédica-RJ. Morphological patterns were used to identify the formation pathway (biogenic and physiogenic) of aggregates. In these, fertility, total organic carbon (TOC), and total nitrogen (TN) were evaluated. The evolution and accumulation of C-CO2 were determined in the laboratory after 35 days of incubation. The biological and physiogenic aggregates of the different agricultural management systems resulted in peaks of C-CO2 evolution up to the 20th day of incubation, with stabilization at 35 days of evaluation. The NT area under agroecological management presented higher C-CO2 accumulation among the systems with biogenic aggregates and less accumulation in the physiogenic aggregates.

Keywords : Biogenic aggregates; carbon mineralization; respiration.

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