Data/hora: 19/06/2024 00:56:00

Biblioteca(s): 	Embrapa Cerrados.	
Data corrente: 	16/07/1999	
Data da última atualização: 	16/07/1999	
Autoria: 	LILIENFEIN, J.; WILCKE, W.; NEUFELDT, H.; AYARZA, M. A.; ZECH, W.	
Título: 	Phosphorus pools in bulk soil and aggregates of differently textured oxisols under different land-use systems in the Brazilian cerrados.	
Ano de publicação: 	1999	
Fonte/Imprenta: 	In: THOMAS, R.; AYARZA, M.A., ed. Sustainable land management for the oxisols of the Latin American savannas: dynamics of soil organic matter and indicators of soil quality. Cali: CIAT, 1999.	
Páginas: 	p.159-172.	
Idioma: 	Inglês	
Conteúdo: 	This study assessed the influence of land use (continuous cropping, CC; tree plantations, F; pastures, PG; and native savanna, NS) on P concentrations and partitioning in bulk soil and two aggregate size fractions of two Oxisols, one loamy and one clayey. The quantity and quality of physically protected P within aggregates were also determined. Total P in bulk soil and macroaggregates (0.25-2 mm and 2/8 mm) was partitioned into inorganic and organic P fractions (Pi and Po, respectively) after sequential extractionally, P binding was examined with 31P nuclear magnetic resonance spectroscopy. Total P concentrations were 70-170 mg/kg in the loamy and 300-450 mg/kg in the clayey soil. The largest P fraction was the NaOH-soluble P (33%-55% of total P concentration). The proportion of easily extractable P was higher in the loamy than in the clayey soil. Because of fertilization, CC and F had higher total and, particularly, higher easily available P concentrations than NS and PG. In the loamy soil Pi and, in the clayey soil, both Pi and Po, were higher in CC and F than in NS and PG. In the loamy soil, P concentrations in macroaggregates (>2mm) were higher than in bulk soil. Higher monoester P proportions within the large mnacroaggregates in unplowed systems indicated older intra-aggregate soil organic matter that at the aggregate surfaces. In the plowed systems, the monoester/diester ratio was not different between bulk soil and aggregate fractions, indicating faster aggregate turnover.	
Thesagro: 	Cerrado; Estrutura do Solo; Fósforo; Fracionamento; Oxisol; Uso da Terra.	
Thesaurus Nal: 	Ferralsols; fractionation; land use; phosphorus; soil structure.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Cerrados (CPAC)	
Exemplares: 	CPAC - (2463-1) - ADD - PL - -- - CRI4998 -  - CRI4998 - DIS