Data/hora: 09/06/2024 16:50:30

Biblioteca(s): 	Embrapa Acre; Embrapa Agropecuária Oeste.	
Data corrente: 	26/11/2009	
Data da última atualização: 	12/12/2011	
Autoria: 	GOMES, J.; BAYER, C.; COSTA, F. de S.; PICCOLO, M. de C.; ZANATTA, J. A.; VIEIRA, F. C. B.; SIX, J.	
Afiliação: 	JULIANA GOMES, UFRGS; CIMÉLIO BAYER, UFRGS; FALBERNI DE SOUZA COSTA, CPAF-AC; MARISA DE CÁSSIA PÍCCOLO, CENA/USP; JOSILÉIA ACORDI ZANATTA, CPAO; FREDERICO COSA BEBER VIEIRA, UFP; JOHAN SIX, UNIVERSITY OF CALIFORNIA.	
Título: 	Soil nitrous oxide emissions in long-term cover crops-based rotations under subtropical climate.	
Ano de publicação: 	2009	
Fonte/Imprenta: 	Soil & Tillage Research, v. 106, n. 1, p. 36-44, Dec. 2009.	
DOI: 	10.1016/j.still.2009.10.001	
Idioma: 	Inglês
Português	
Conteúdo: 	It has been shown that cover crops can enhance soil nitrous oxide (N2O) emissions, but the magnitude of increase depends on the quantity and quality of the crop residues. Therefore, this study aimed to evaluate the effect of long-term (19 and 21 years) no-till maize crop rotations including grass [black oat (Avena strigosa Schreb)] and legume cover crops [vetch (Vigna sativa L.), cowpea (Vigna unguiculata L. Walp), pigeon pea (Cajanus cajan L. Millsp.) and lablab (Dolichos lablab)] on annual soil N2O emissions in a subtropical Acrisol in Southern Brazil. Greater soil N2O emissions were observed in the first 45 days after the cover crop residue management in all crop rotations, varying from -20.2 ± 1.9 to 163.9 ± 24.3 ug N m-2 h-1. Legume-based crop rotations had the largest cumulative emissions in this period, which were directly related to the quantity of N (r2 = 0.60, p = 0.13) and inversely related to the lignin:N ratio (r2 = 0.89, p = 0.01) of the cover crop residues. After this period, the mean fluxes were smaller and were closely related to the total soil N stocks (r2 = 0.96, p = 0.002). The annual soil N2O emission represented 0.39-0.75% of the total N added by the legume cover crops. Management-controlled soil variables such as mineral N (NO3- and NH4+) and dissolved organic C influenced more the N2O fluxes than environmental-related variables as water-filled pore space and air and soil temperature. Consequently, the synchronization between N mineralization and N uptake by plants seems to be the main challenge to reduce N2O emissions while maintaining the environmental and agronomic services provided by legume cover crops in agricultural systems.	
Palavras-Chave: 	Aveia preta; Caupi; Cero labranza; Clima subtropical; Cultivo de cobertura; Cultivos de cobertura; Emisiones de gases de efecto invernadero; Labe-labe; Legumbres; Manejo del suelo; Óxido nitroso; Pastos forrajeros; Rotación de cultivos; Subtrópico.	
Thesagro: 	Aveia forrageira; Avena strigosa; Cajanus cajan; Dolichos lablab; Efeito Estufa; Ervilhaça; Feijão de corda; Gramínea forrageira; Guandu; Leguminosa; Manejo do solo; Plantio direto; Rotação de cultura; Solo; Vicia sativa; Vigna unguiculata.	
Thesaurus Nal: 	Cover crops; Crop rotation; Forage grasses; Greenhouse gas emissions; Legumes; Nitrous oxide; No-tillage; Soil management; Subtropics.	
Categoria do assunto: 	--
P Recursos Naturais, Ciências Ambientais e da Terra	
URL: 	http://ainfo.cnptia.embrapa.br/digital/bitstream/item/50000/1/14.pdf	
Registro original: 	Embrapa Agropecuária Oeste (CPAO)	
Exemplares: 	CPAF-AC - (22554-1) - UPC - SP - PP - SP 245 -  - 2009.02093 - DES
CPAF-AC - (22554-2) - UPC - AP - DD -  -  -  - DIS
CPAO - (32108-1) - UPC - AP - PP - SEP 109 -  - SIDE 14/09 - DIS