Costa C., Piccolo M. D., Neto M. S., de Camargo P. B., Cerri C. C., Bernoux Martial. (2012). Carbono em agregados do solo sob vegetação nativa, pastagem e sistemas agrícolas no bioma Cerrado = Carbon in soil aggregates under native vegetation, pasture and agricultural systems in the brazilian savannah. Revista Brasileira de Ciencia do Solo, 36 (4), p. 1311-1321. ISSN 0100-0683.
Titre du document
Carbono em agregados do solo sob vegetação nativa, pastagem e sistemas agrícolas no bioma Cerrado = Carbon in soil aggregates under native vegetation, pasture and agricultural systems in the brazilian savannah
Costa C., Piccolo M. D., Neto M. S., de Camargo P. B., Cerri C. C., Bernoux Martial
Source
Revista Brasileira de Ciencia do Solo, 2012,
36 (4), p. 1311-1321 ISSN 0100-0683
Soil organic matter (SOM) is responsible for soil fertility, nutrient cycling and structure stability and is closely related with soil aggregation. However, the relationship between aggregate size classes in the SOM dynamics is unclear, resulting in SOM accumulation or loss due to soil land use and management. This study aimed to evaluate the amount of carbon (C) in soil aggregates under four uses and management: native Cerrado (CE-savannah vegetation), no-tillage (NT), conventional tillage (SPC) and pasture (PA). The study areas are located in Rio Verde (GO) where the soil was classified as kaolinitic clayey Oxisol. The soil layers 0-5, 5-10 and 10-20 cm were sampled (n=6) in February 2007, and the amount of water-stable macroaggregates (> 2.0 mm), mesoaggregates (> 0.25 and < 2.00 mm) and microaggregates (> 0.05 and < 0.25 mm) were determined, as well as the mean weight diameter (MWD) and mean geometric diameter (MGD), and the C levels in the soil aggregate classes. Macroaggregates were predominant in the soil evaluated, with higher quantities in CE and PA compared NT and SPC soils, indicating a negative effect of soil cultivation on macroaggregate conservation. However, the soil aggregate C levels in the 0-20 cm layer were higher in CE and SPD than in PA and SPC soils, suggesting that the absence of tillage and maintenance of crop residues on the soil drives C accumulation. This shows that macroaggregates and mesoaggregates were more sensitive to soil use and management than microaggregates. The similarities of aggregation in PA and CE soils, although with lower C levels in PA suggested different aggregation dynamics, requiring further research.
