Data/hora: 09/06/2024 18:46:36

Biblioteca(s): 	Embrapa Trigo.	
Data corrente: 	10/01/2010	
Data da última atualização: 	17/10/2011	
Autoria: 	AMER, F.; BOULDIN, D. R.; BLACK, C. A.; DUKE, F. R.	
Título: 	Characterization of soil phosphorus by anion exchange resin adsorption and P32-equilibration.	
Ano de publicação: 	1955	
Fonte/Imprenta: 	Plant and Soil, The Hague, v. 6, n. 4, p. 391-408, 1955.	
Idioma: 	Inglês	
Conteúdo: 	Adsorption of phosphate by the anion-exchange resin Dowex-2 was investigated. The resin adsorbed small quantities of P from solution quantitatively. The rate of P-adsorption by resin agitated in solution was proportional to the P-concentration in solution, and was independent of the rate of diffusion of adsorbed P in the resin. When 1 g of soil was shaken continuously with 1 g of resin in 100 ml of water, the rate of P-adsorption by the resin was controlled by the rate of P-release from the soil. Quantities of P adsorbed from soil by resin after different lengths of time were less than those equilibrated with P32 during the same time intervals. The curves showing quantity of P adsorbed vs. time could be satisfactorily described by the hypothesis that there were three simultaneous reactions differing in rate, each reaction being first-order with respect to P. The same was true of the P32-equilibration data, except that the rate of the slowest reaction was apparently independent of time. In a group of 16 soils, the correlation between P adsorbed by the resin in 2 hours and P-availability to plants in the greenhouse, measured by the isotope-dilution method of Fried and Dean, was 0.95. The corresponding correlation between P extracted by the 0.25N HCl — 0.03N NH4F extractant of Bray and Kurtz was 0.91.	
Thesagro: 	Análise; Fósforo; Solo.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Trigo (CNPT)	
Exemplares: 	CNPT - (15510-1) - ADD - SP - -- - 01591 -  - 01591 - DIS