Data/hora: 03/06/2024 05:23:56

Biblioteca(s): 	Embrapa Pantanal.	
Data corrente: 	08/06/1995	
Data da última atualização: 	08/06/1995	
Autoria: 	BIGHAM, J. M.; GOLDEN, D. C.; BUOL, S. W.; WEED, S. B.; BOWEN, L. H.	
Título: 	Iron oxide mineralogy of well-drained ultisols and oxisols: II. Influence on color, surface area, and phosphate retention.	
Ano de publicação: 	1978	
Fonte/Imprenta: 	Soil Science Society of America Journal, v.42, p.825-829, 1978.	
Idioma: 	Inglês	
Conteúdo: 	Subsoil samples from selected North Carolina Ultisols and Brazilian Oxisols were analyzed to determine how the colors of these materials were influenced by the nature and distribution of their constituent iron oxides. The effects of extraneous variables, i.e., other than the iron oxides, were minimized by utilizing pairs of red and yellow soils that were otherwise similar in their physical, morphological, and mineralogical properties. The iron oxides were found to be concentrated in the <0.2- um fractions, and the colors of these clays were the same as or similar to those of the parent soils. The spectral properties of the <0.2- um clays were primarily influenced by iron mineralogy. Goethite or mixtures of goethite and hematite were identified in all of the clays; however, Mossbauer analyses indicated that the red members of all sample pairs contained larger proportions of hematite than did their yellow counterparts. In addition, as the clays became redder in hue, the ratio of hematite to goethite generally increased. Calculated surface areas for the iron oxides ranged from 60 to 200 m2/g; values from the yellow clays were consistently higher than those obtained from their red counterparts. The yellow clays were also more efficient adsorbers of phosphate.	
Palavras-Chave: 	Fertility.	
Thesagro: 	Fertilidade; Oxido de Ferro; Solo.	
Thesaurus Nal: 	goethite; hematite; iron oxides; Mossbauer spectroscopy; soil.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Pantanal (CPAP)	
Exemplares: 	CPAP - (28206-1) - ADD - SP - -- - SP0079 -  - 0079 - DIS