Data/hora: 05/05/2024 05:31:03

Biblioteca(s): 	Embrapa Arroz e Feijão.	
Data corrente: 	08/12/2011	
Data da última atualização: 	30/03/2012	
Autoria: 	RODRIGUES, C.; OLIVEIRA, V. A. de; SILVEIRA, P. M. da; SANTOS, G. G.	
Afiliação: 	CRISTIANE RODRIGUES, Solocria Laboratório Agropecuária, Goiânia-GO; VIRLEI ÁLVARO DE OLIVEIRA, IBGE; PEDRO MARQUES DA SILVEIRA, CNPAF; GLENIO GUIMARÃES SANTOS, UNIVERSIDADE FEDERAL DO PIAUÍ.	
Título: 	Chemical dispersants and pre-treatments to determine clay in soils with different mineralogy.	
Ano de publicação: 	2011	
Fonte/Imprenta: 	Revista Brasileira de Ciência do Solo, Viçosa, MG, v. 35, n. 5, p. 1589-1596, set./out. 2011.	
Idioma: 	Inglês	
Conteúdo: 	Knowledge of the soil physical properties, including the clay content, is of utmost importance for agriculture. The behavior of apparently similar soils can differ in intrinsic characteristics determined by different formation processes and nature of the parent material. The purpose of this study was to assess the efficacy of separate or combined pre-treatments, dispersion methods and chemical dispersant agents to determine clay in some soil classes, selected according to their mineralogy. Two Brazilian Oxisols, two Alfisols and one Mollisol with contrasting mineralogy were selected. Different treatments were applied: chemical substances as dispersants (lithium hydroxide, sodium hydroxide, and hexametaphosphate); pre-treatment with dithionite, ammonium oxalate, and hydrogen peroxide to eliminate organic matter; and coarse sand as abrasive and ultrasound, to test their mechanical action. The conclusion was drawn that different treatments must be applied to determine clay, in view of the soil mineralogy. Lithium hydroxide was not efficient to disperse low-CEC electropositive soils and very efficient in dispersing high-CEC electronegative soils. The use of coarse sand as an abrasive increased the clay content of all soils and in all treatments in which dispersion occurred, with or without the use of chemical dispersants. The efficiency of coarse sand is not the same for all soil classes.	
Palavras-Chave: 	Agentes químicos; Partículas do solo.	
Thesagro: 	Argila; Classificação do solo; Perfil do solo.	
Categoria do assunto: 	P Recursos Naturais, Ciências Ambientais e da Terra	
URL: 	http://ainfo.cnptia.embrapa.br/digital/bitstream/item/49716/1/a13v35n5.pdf	
Registro original: 	Embrapa Arroz e Feijão (CNPAF)	
Exemplares: 	CNPAF - (30961-1) - UPC - AP - DD - 2011.052 -  - 2011.052 - DIS