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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Greenhouse gas emission caused by different land-uses in brazilian Savannah

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Author(s):
Marcos Siqueira Neto [1] ; Marisa de Cássia Piccolo [2] ; Ciniro Costa Junior [3] ; Carlos Clemente Cerri [4] ; Martial Bernoux [5]
Total Authors: 5
Affiliation:
[1] Universidade de São Paulo. Centro de Energia Nuclear na Agricultura
[2] USP. CENA. Laboratório de Biogeoquímica Ambiental
[3] USP. CENA. Laboratório de Ciclagem de Nutrientes
[4] USP. CENA. Laboratório de Biogeoquímica Ambiental
[5] USP. CENA. Laboratório de Biogeoquímica Ambiental
Total Affiliations: 5
Document type: Journal article
Source: Revista Brasileira de Ciência do Solo; v. 35, n. 1, p. 63-76, 2011-02-00.
Abstract

The conversion of native forests by cutting and burning into farming areas leads to alterations in the dynamics of soil organic matter, with changes in emissions of greenhouse gases (GHGs: CO2, CH4 and N2O) from the biosphere to the atmosphere. These cause an average temperature rise and, consequently, global climate change. The aim of this study was to examine relationships between the fluxes of CO2, CH4 and N2O with moisture, microbial biomass and inorganic N forms in soil with different land uses in the Cerrado biome (Rio Verde county, State of Goias - Brazil). The climate (Köppen-Geiger) was classified as Aw and the soil as Latossolo Vermelho distrófico caulinítico / a clayey kaolinitic Oxisol under original Cerrado (Brazilian savanna) vegetation. The experiment was arranged in a completely randomized design (CRD) with four treatments (areas): Native vegetation - Cerrado (CE); brachiaria pasture (PA); soybean in conventional tillage (SC) and no-tillage (NT) corn followed by millet. No significant differences in annual CO2 and N2O emissions were observed between treatments. This can be explained by the variability of gas fluxes due to climate seasonality, with lower emissions in the winter due to low soil moisture. Mean emissions of CO2 were 108.9 ± 85.6 mg m-2 h-1 , and of N2O 13.5 ± 7.6 mg m-2 h-1 . For CH4 significant differences in the fluxes were only observed in pasture (32 mg m-2 h-1 ), while in the other areas inflows between 46 and 15 mg m-2 h-1 were observed. The GHG fluxes showed close correlation with soil moisture. The N-NO3- emissions were significantly correlated with CO2-emissions in all areas. Considering all treatments together, the three GHG fluxes were correlated with the microbial C and N contents. However, the Cmicro: Nmicro ratio was not significantly correlated with the GHG flux. Only for pasture the CO2 and N2O fluxes were correlated with the content of soil inorganic-N. Results suggested that the GHG fluxes in the Cerrado are related to rainfall, mainly in farming areas treated with high fertilizer doses to increase productivity. (AU)

FAPESP's process: 04/15538-7 - Stocks of carbon and nitrogen in Cerrado soils aimed at agricultural sustainability
Grantee:Marisa de Cassia Piccolo
Support Opportunities: Regular Research Grants