Data/hora: 23/09/2024 18:15:00

Biblioteca(s): 	Embrapa Acre; Embrapa Meio Ambiente.	
Data corrente: 	31/10/2014	
Data da última atualização: 	06/07/2021	
Autoria: 	BAYER, C.; COSTA, F. de S.; PEDROSO, G. M.; ZSCHORNACK, T.; CAMARGO, E. S.; LIMA, M. A. de; FRIGHETTO, R. T. S.; GOMES, J.; MARCOLIN, E.; MACEDO, V. R. M.	
Afiliação: 	CIMELIO BAYER, UFRGS; FALBERNI DE SOUZA COSTA, CPAF-AC; GABRIEL MUNHOZ PEDROSO, UFRGS; TIAGO ZSCHORNACK, Instituto Riograndense do Arroz; ESTEFANIA S CAMARGO, UFRGS; MAGDA APARECIDA DE LIMA, CNPMA; ROSA TOYOKO SHIRAISHI FRIGHETTO, CNPMA; JULIANA GOMES, UFRGS; ELIO MARCOLIN, Instituto Riograndense do Arroz; VERA REGINA MUSSOI MACEDO, Instituto Riograndense do Arroz.	
Título: 	Yield-scaled greenhouse gas emissions from flood irrigated rice under long-term conventional tillage and no-till systems in a Humid Subtropical climate.	
Ano de publicação: 	2014	
Fonte/Imprenta: 	Field Crops Research, Amsterdam, v. 162, p. 60-69, June 2014.	
ISSN: 	0378-4290	
DOI: 	http://dx.doi.org/10.1016/j.fcr.2014.03.015	
Idioma: 	Inglês	
Conteúdo: 	Abstract: Soils under flooded rice (Oryza sativa L.) production are one of the major anthropogenic source of CH4 emissions, an important greenhouse gas (GHG) with a 25-times larger global warming potential (GWP) than CO2. No-till systems (NT) systems may be a viable alternative to mitigate GHG emissions in comparison to conventional tillage (CT). The objectives of this study were to evaluate on a field scale the long-term effects of CT and NT systems on soil CH4 and N2O emissions, rice yields and yield-scaled emissions during five growing seasons (GS) in Southern Brazil. In addition, a short-term greenhouse experiment was conducted to isolate the effect of winter crop [ryegrass (Lolium multiflorum L.)] biomass incorporation on soil CH4 efflux. Averaged across years, the NT system resulted in 21% lower seasonal CH4 emissions than the CT system, at 408 and 517 kg CH4 ha-1 GS-1, respectively. No significant effect of tillage system on N2O emissions was observed. Methane emission was responsible for 96.5% of partial GWP (pGWP = CH4 × 25 + N2O × 298), stressing the importance of this GHG for developing low GHGs rice systems. No significant effect of tillage system on rice grain yields (average of 7.8 Mg ha-1 GS-1) was detected. Consequently, the NT system resulted in 23% lower yield-scaled pGWP, at 1.35 and 1.76 kg CO2eq kg-1 grain for NT and CT treatments, respectively. According to the greenhouse study, the incorporation of ryegrass biomass into the soil resulted in 2.8 times larger cumulative CH4 emission than the surface application of biomass, at 347.4 and 125.5 g CH4 m-2, respectively, due to higher dissolved organic carbon (DOC) concentration and reduced soil environment in subsurface soil layers. Our results indicate that biomass incorporation is the main cause of higher CH4 emissions from conventionally tilled soil and that NT system is a viable alternative to reduce yield-scaled GHG emissions from flooded rice fields.	
Palavras-Chave: 	Cambio climático; Cero labranza; Condiciones inundadas; Cultivo del suelo; Flooded rice; Gases de invernadero; Global warming potential; Interacciones suelo-atmósfera; No-till system; Producción de dióxido de carbono; Producción de metano.	
Thesagro: 	Arroz inundado; Clima; Dióxido de carbono; Efeito estufa; Metano; Mudança climática; Oryza sativa; Plantio; Plantio direto; Solo.	
Thesaurus Nal: 	Carbon dioxide production; Climate change; Flooded conditions; greenhouse gases; methane; Methane production; nitrous oxide; No-tillage; Rice; Soil-atmosphere interactions; Tillage.	
Categoria do assunto: 	P Recursos Naturais, Ciências Ambientais e da Terra	
Registro original: 	Embrapa Acre (CPAF-AC)	
Exemplares: 	CNPMA - (13212-1) - UPC - AP - DD -  -  -  - DIS
CPAF-AC - (25350-1) - UPC - AP - PP - SP 339 -  - 2014.00494 - DES
CPAF-AC - (25350-2) - UPC - AP - DD -  -  -  - DIS