Data/hora: 10/06/2024 09:05:47

Biblioteca(s): 	Embrapa Gado de Corte.	
Data corrente: 	05/11/2001	
Data da última atualização: 	05/11/2001	
Autoria: 	KANDA, K.; TAKAHSHI, M.; MIRANDA, C. H. B.	
Afiliação: 	Japan International Research Center for Agricultural Sciences (JIRCAS).	
Título: 	Nitrogen flow in agropastoral systems, Brazil.	
Ano de publicação: 	2001	
Fonte/Imprenta: 	JIRCAS Journal, Isukuba, n.9, p.23-31, mar. 2001.	
Idioma: 	Inglês	
Notas: 	CNPGC.	
Conteúdo: 	Agropastoral systems that combine soybean and grasses in a crop rotation have been proposed for sustaining grassland productivity in the low-fertility soils of the Brazilian savanna. We studied the nitrogen flow under an agro-pastoral system developed in 1993 in a Purple Red Latosol in Campo Grande, MS. Four cropping  systems were included: continuous soybean cropping, soybean cropping after 4 years of grass cultivation. continuous grass cultivation, grass cultivation after 4 years of soybean cropping. The rate of  N fixation in soybean was determined by the N difference method and 15N natural abundance method. A  non-modulating isoline, T201, was used as a control in both methods. The rate of N2 fixation rangel from 23 to 51% of the total plant N. The amount of N taken out as grains was larger than the amount of fixed N in soybean. the amount of entering the system through rainwater was 6 kgN/ha/yr. Nitrato accumulating in soil from the surface to a deph of 100 cm under soybeans  indicated the potential leaching of nitrate. The estimated  amount of nitrate leaching from the soybean fields was large compared with that from the grasslands. A large negative N balance of 134-211 kgN/ha/yr was estimated in the  soybean fields, whereas the N balance in the grasslands was a sligtly negative. 	
Palavras-Chave: 	Agropastoral systems; Basilisk; Brasil; Brazilian savannas; Campo Grande; Integracao agricultura pecuaria; Mato Grosso do Sul.	
Thesagro: 	Brachiaria Decumbens; Cerrado; Nitrogênio; Panicum Maximum; Pastagem; Soja.	
Thesaurus Nal: 	Brazil; nitrogen; pastures; soybeans.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Gado de Corte (CNPGC)	
Exemplares: 	CNPGC - (8877-1) - UPC - AP - -- - 630.5 -  - 630.5 - DIS