BBEST 2011
Resume:347-1


Poster (Painel)
347-1FLUXES OF GREEN HOUSE GASES (N2O, CO2, CH4) FROM A SUGARCANE CROP UNDER DIFFERENT SOIL MANAGEMENTS IN SÃO PAULO STATE, BRAZIL
Authors:Sousa Neto (CENA-USP - Centro de Energia Nuclear na Agricultura) ; Carmo (UFSCAR - Universidade Federal de São Carlos) ; Pitombo (UFSCAR - Universidade Federal de São CarlosIAC - Instituto Agronômico de Campinas) ; Andrade (IAC - Instituto Agronômico de Campinas) ; Cantarella (IAC - Instituto Agronômico de Campinas) ; Gava (APTA - Agência Paulista de Tecnologia dos Agronegócios) ; Fantini (CENA-USP - Centro de Energia Nuclear na Agricultura) ; Martineli (CENA-USP - Centro de Energia Nuclear na Agricultura)

Resume

Sugar cane in Brazil is expanding; and consequently there will be an increase in the use of N fertilizers and solid and liquid residues of the sugar cane industry used as soil amendments. This fact could potentially increase green house gases (GHG) emissions into the atmosphere, especially N2O. The lack of field measurements about emissions of GHG associated with sugar cane cultivation hinders our capacity to properly quantify such emissions. The objective of this study was to measure GHG emissions to the atmosphere from a plant cane experiment containing five different randomized treatments. Treatments are as follows: (T0) Control; (T1) N-P-K via mineral fertilizers (60 kg N ha-1 yr-1); (T2) N via filter cake and P-K via mineral fertilizers (135 kg N ha-1 yr-1); (T3) N-P via mineral fertilizers and K via vinasse (80 kg N ha-1 yr-1); (T4) N-P-K via mineral fertilizers, filter cake and vinasse (220 kg N ha-1 yr-1). Here we present the first five months of data. The highest CO2 emission was observed in T4 (11.7 g C m-2 day-1), followed by T3 (8.1 g C m-2 day-1) and T2 (8.7 g C m-2 day-1). The lowest CO2 emissions were observed in T1 and control. It was observed CH4 consumption, and only T4 presented emission (0.02 kg ha-1 yr-1). The highest net emissions of N2O was observed in T4 (908 g.ha-1.y-1) followed by T2 and T3 that were half of T4. The N2O lowest emissions were observed in T1 and control. The emission factors (EF) for N2O were 1.12% (T1), 0.73% (T2), 1.26% (T3) and 0.81% (T4). The EFs estimated in our study are approximated to the factor proposed (1%) by the IPCC (2006). Our results suggest that the application of 60 to 140 kgN.ha-1.y-1 via mineral fertilizers and vinasse enhance GHG emissions in plant cane.


Keyword:  sugar cane, ethanol, green house gases, vinasse, filter cake