Isotopic variations of carbon and nitrogen and their implications on the conversion of Cerrado vegetation into pasture

Conversions of natural vegetation into pasture can, in a short time, change the carbon stock and abundance δ13C soil. The objective this study was to evaluate changes (C) nitrogen (N) stocks, as well δ15N Argissolo Vermelho distrófico (Acrisol), an area planted Cerrado region Aquidauana (MS), Brazil. In order do this, (PA), cultivated for 25 years with Urochloa brizantha, (NV) were evaluated. Soil samples collected at intervals 0.05 m up 0.60 depth, physical attributes, C N stocks (CSt NSt) isotopic variations soil determined. 0–0.05 layer, highest occurred NV, 21.99 1.9 Mg ha-1, respectively. conversion PA, 14.62 ha-1 CSt 1.36 NSt lost layer. PA had greater enrichment layers 0.05–0.10 m, values -18.3 -17.4‰, respectively, while other decreased mixture between C3 C4 plants. NV showed signals, from 0.25–0.30 0.40–0.45 -21.74 -21.54‰, which is characteristic mixed δ15 depth increased, indicating mineralization organic matter both areas. its consequent fragmentation causes negative impacts on sequestration storage capacity, vegetation.