Data/hora: 06/06/2024 07:39:51

Biblioteca(s): 	Embrapa Soja.	
Data corrente: 	22/04/2014	
Data da última atualização: 	09/11/2015	
Autoria: 	LUCA, M. J. de; HUNGRIA, M.	
Afiliação: 	MARCOS JAVIER DE LUCA, INTA; MARIANGELA HUNGRIA DA CUNHA, CNPSO.	
Título: 	Plant densities and modulation of symbiotic nitrogen fixation in soybean.	
Ano de publicação: 	2014	
Fonte/Imprenta: 	Scientia Agricola, Piracicaba, v. 71, n. 3, p. 181-187, May/June 2014.	
ISSN: 	0103-9016	
DOI: 	http://dx.doi.org/10.1590/S0103-90162014000300002	
Idioma: 	Inglês	
Conteúdo: 	Soybean nitrogen (N) demands can be supplied to a large extent via biological nitrogen fixation, but the mechanisms of source/sink regulating photosynthesis/nitrogen fixation in high yielding cultivars and current crop management arrangements need to be investigated. We investigated the modulation of symbiotic nitrogen fixation in soybean [Glycine max (L.) Merrill] at different plant densities. A field trial was performed in southern Brazil with six treatments, including non-inoculated controls without and with N-fertilizer, both at a density of 320,000 plants ha&#8722;1, and plants inoculated with Bradyrhizobium elkanii at four densities, ranging from 40,000 to 320,000 plants ha&#8722;1. Differences in nodulation, biomass production, N accumulation and partition were observed at stage R5, but not at stage V4, indicating that quantitative and qualitative factors (such as sunlight infrared/red ratio) assume increasing importance during the later stages of plant growth. Decreases in density in the inoculated treatments stimulated photosynthesis and nitrogen fixation per plant. Similar yields were obtained at the different plant densities, with decreases only at the very low density level of 40,000 plants ha&#8722;1, which was also the only treatment to show differences in seed protein and oil contents. Results confirm a fine tuning of the mechanisms of source/sink, photosynthesis/nitrogen fixation under lower plant densities. Higher photosynthesis and nitrogen fixation rates are capable of sustaining increased plant growth.	
Thesagro: 	Fixação de nitrogênio; Soja.	
Thesaurus Nal: 	Nitrogen fixation; Soybeans.	
Categoria do assunto: 	S Ciências Biológicas	
URL: 	http://ainfo.cnptia.embrapa.br/digital/bitstream/item/104204/1/Plant-densities-and-modulation-of-symbiotic-nitrogen-fixation-in-soybean.pdf	
Registro original: 	Embrapa Soja (CNPSO)	
Exemplares: 	CNPSO - (35124-1) - UPC - AP - PP - 12137 -  - 12137 - DIS