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Revista Brasileira de Ciência do Solo

On-line version ISSN 1806-9657

Rev. Bras. Ciênc. Solo vol.22 no.2 Viçosa Apr./June 1998

http://dx.doi.org/10.1590/S0100-06831998000200007 

SEÇÃO II - QUÍMICA E MINERALOGIA DO SOLO

 

Adsorção de fósforo e sua relação com formas de ferro em dez solos do Uruguai(1)

 

Phosphorus sorption in soils from Uruguay and its relationship with iron oxides

 

 

J. HernándezI; E. J. MeurerII

IProfessor da Facultad de Agronomia. Universidad de la Republica. Montivideo, Uruguay
IIProfessor do Departamento de Solos da Faculdade de Agronomia, Universidade Federal do Rio Grande do Sul. Caixa Postal 776, CEP 90001-970 Porto Alegre (RS). Bolsista do CNPq

 

 


RESUMO

Oxihidróxidos de ferro formam ligações químicas muito fortes com ânions fosfatos, diminuindo suas disponibilidades para as plantas. Este trabalho foi realizado em 1994 e 1995, com os objetivos de quantificar formas de ferro em solos do Uruguai e de relacioná-las com a adsorção de fósforo. Em amostras superficiais (0 a 15 cm) do horizonte A de dez solos, o ferro extraído com ditionito (Fed) variou entre 1.598 e 8.592 mg kg-1 e esteve relacionado com o material de origem. As formas de ferro de baixa cristalinidade, extraídas com oxalato de amônio 0,2 mol L-1 pH 3 (Fe03), representaram de 45 a 78% do total extraído com o ditionito. A capacidade máxima de adsorção de fósforo (K2), calculada a partir do modelo de Langmuir, variou de 104 a 704 mg kg-1. Encontrou-se correlação significativa (r = 0,894, P < 0,01) entre as formas de óxidos de ferro de baixa cristalinidade (Fe03) e a adsorção de fósforo pelos solos. A porcentagem de fósforo adsorvida pelos solos após a adição de 600 mg de P kg-1 (P600) relacionou-se significativamente (r = 0,975, P < 0,01) com a capacidade máxima de adsorção de fósforo pelos solos. Também apresentou alta correlação (r = 0,894, P < 0,01) com as formas de ferro de baixa cristalinidade (Fe03), e pode ser utilizado como um índice para estimar a capacidade de adsorção de fósforo desses solos.

Termos de indexação: adsorção de fósforo, adsorção máxima, energia de ligação, equação de Langmuir, óxidos de ferro.


SUMMARY

Iron oxihydroxides form strong chemical bonds with phosphate anions, reducing P availability to plants. The objective of this study, conducted in 1994/95, was to quantify forms of iron oxides in soils from Uruguay, and to study their relationships with phosphorus sorption. Iron oxides extracted with dithionite-citrate-bicarbonate (Fed) from ten soil samples (0-15 cm depth) ranged from 1598 to 8.592 mg kg-1 and were related with their parent material. Poorly ordered Fe-oxihydroxides, extracted by 0.2 mol L-1 ammonium oxalate at pH 3 (Fe03), ranged from 45.2 to 78.2% of the total iron oxides extracted by dithionite. The maximum P-sorption soil capacity (K2), estimated by the Langmuir equation, ranged from 104 to 704 mg kg-1 of soil. The P sorption was strongly correlated (r = 0.894, P < 0.01) with the poorly ordered iron oxides (Fe03). The percent of phosphorus sorbed by soils after equilibrium with 600 mg kg-1 P (P600), was significantly correlated (r = 0.975, P < 0.01) with the maximum P-sorption capacity and, with poorly crystalline Fe-minerals (r = 0.894, P < 0.01) extracted by the 0.2 mol L-1 oxalate ammonium pH 3. This index can be used to estimate the P-sorption capacity of these soils.

Index terms: phosphorus sorption, maximum adsorption, binding energy, Langmuir equation, iron oxides.


 

 

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LITERATURA CITADA

BALLARD, R.& FISKELL, J.G.A. Phosphorus reaction in Coastal Plain Forest soils: I. Relationship to soil properties. Soil Sci. Soc. Am. Proc., 38:250-255, 1974.         [ Links ]

BLUME, H.P. The fate of iron during soil formation in humid-temperate environments. In: STUCKI, J.W., ed. Iron in soils and clay minerals. Holland, D. Reidel Publishing, 1988. p.749-777.         [ Links ]

BRADLEY, J.; VIMPANY, I.& NICHOLLS, P.J. Effects of water logging and subsequent drainage of a pasture soil on phosphate sorption, extractable phosphate and oxalate-extractable iron. Aust. J. Soil Res., 22:455-461, 1984.         [ Links ]

BROMFIELD, I.S.M. Studies of the relative importance of iron and aluminum in the sorption of phosphate by some australian soils. Aust. J. Soil Res., 3:31-44, 1965.         [ Links ]

CAYSSIALS, R. & PUENTES, R. Determinación y fraccionamiento de hierro y aluminio libre en algunos suelos del Uruguay. Montevideo, Facultad de Agronomía, 1974. 88p. (Tesis Ingeniero Agrónomo)        [ Links ]

DELVAUX, B.; HERBILLON, A.J. & VIELVOYE, L. Characterization of a weathering sequence of soils derived from volcanic ash in Cameroon. Taxonomic, mineralogical and agronomic implications. Geoderma, 45:375-388, 1989.         [ Links ]

DICK, D.P. Caracterizaçao de óxidos de ferro e adsorção de fósforo na fração argila de horizontes B latossólicos. Porto Alegre, Universidade Federal do Rio Grande do Sul, 1986. 196p. (Tese de Mestrado)        [ Links ]

ESTADOS UNIDOS. Department of Agriculture. Soil Survey Staff. Keys to soil taxonomy, 5. Blaksburg, Pocahontas, 1992. 56p. (SMSS Technical Monograph, 19)        [ Links ]

HERNANDEZ, J.; OTEGUI, O.& ZAMALVIDE, J.P. Formas y contenidos de fósforo en algunos suelos del Uruguay. Montevideo, Facultad de Agronomía, 1985. 32p. (Boletín de Investigaciones, 43)        [ Links ]

KÄMPF, N. O ferro no solo. In: REUNIÃO SOBRE FERRO EM SOLOS INUNDADOS, 1., Goiania, 1988. Anais. Goiânia, EMBRAPA-CNAF, 1988. p.35-71 (Documentos, 22).         [ Links ]

KHALID, R.A.; PATRICK, W.H.& DE LAUNE, R.D. Phosphorus sorption characteristics of flooded soils. Soil Sci. Soc. Am. J., 41:305-310, 1977.         [ Links ]

KILMER, V. The estimation of free iron oxides in soils. Soil Sci. Soc. Am. Proc., 24:420-421, 1960.         [ Links ]

LEWIS, D.L.; CLARKE, A.L.& HALL., W.B. Factors affecting the retention of phosphorus applied as Superphosphate to the Sandy soils in South-eastern South Australia. Aust. J. Soil Res., 19:167-174, 1981.         [ Links ]

MADRID, L.& DE ARAMBARRI, P. Adsorption of phosphate by two iron oxides in relation to their porosity. J. Soil Sci., 36:523-530, 1985.         [ Links ]

MEHRA, O.P. & JACKSON, M.L. Iron oxide removal from soils and clays by a dithionite-citrate system buffered with sodium bicarbonate. In: NATIONAL CONFERENCE CLAYS & CLAY MINERALS, 7., Ottawa, 1960. Proceedings. Ottawa, 1960. p.317-327.         [ Links ]

MOLINA, E.; BORNEMISZA, N.; SANCHO, F. & KASS, D.L. Soil aluminum and iron fractions and their relationships with P immobilization and other soil properties in andisols of Costa Rica and Panama. Comm. Soil Sci. Plant Anal., 22:1459-1476, 1991.         [ Links ]

MUNCH, J.C.; HILLEBRAND, T.H. & OTTOW, J.C.G. Transformations in the Feo/Fed ratio of pedogenic iron oxides affected by iron-reducing bacteria. Can. J. Soil Sci., 58:475-486, 1978.         [ Links ]

NISSEN, O. MSTAT-C: Microcomputer Statistical Program. Ann Arbor, Michigan State University, 1989. p.104-106.         [ Links ]

SAH, R.N.; MIKKELSEN, D.S. & HAFEZ, A.A. Phosphorus behavior in flooded-drained soils. II. Iron transformation and phosphorus sorption. Soil Sci. Soc. Am. J., 53:1723-1729, 1989.         [ Links ]

SAS Institute, Inc. SAS User's Guide: Statistics. Cary, 1985.         [ Links ]

SCHWERTMANN, U. Use of oxalate for Fe extraction from soils. Can. J. Soil Sci., 53:224-246, 1973.         [ Links ]

SMITH, B.F.L. & MITCHELL, B.D. Characterization of poorly ordered minerals by selective chemical methods. In: WILSON, M.J., ed. A handbook of determinative methods in clay mineralogy. New York, Blackie, 1987. p.275-294.         [ Links ]

SOON, Y.K. Solubility and retention of phosphate in soils of the northwestern Canadian prairie. Can. J. Soil Sci., 71:453-463, 1991.         [ Links ]

SREE RAMULU, U.S.; PRATT, P.F. & PAGE, A.L. Phosphorus fixation by soils in relation to extractable iron oxides and mineralogical composition. Soil Sci. Soc. Am. Proc., 31:193-196, 1967.         [ Links ]

SYERS, J.K.; EVANS, T.D.; WILLIAMS, J.D.H. & MURDOCK, J.T. Phosphate sorption parameters of representative soils from Rio Grande do Sul, Brazil. Soil Sci., 112:267-275, 1971.         [ Links ]

TEDESCO, M.J.; VOLKWEISS, S.J. & BOHNEN, H. Análises de solo, plantas e outros materiais. Porto Alegre, Universidade Federal do Rio Grande do Sul, 1985. 188p. (UFRGS. Boletim Técnico, 5)        [ Links ]

UEHARA G. & GILLMAN G. The mineralogy, chemistry, and physics of tropical soils with variable charge clays. Boulder, Westview Press, 1981.         [ Links ]

URUGUAY. Ministerio de Agricultura Y Pesca. Dirección de Suelos Y Fertilizantes. Carta de Reconocimiento de Suelos del Uruguay. Montevideo, 1976.         [ Links ]

VAHL, L.C.; ANGHINONI, I. & KAMPF, N. Previsão da acumulação de ferro (II) trocável no solo durante o alagamento através de análise química. In: CONGRESSO BRASILEIRO DE CIÊNCIA DO SOLO, 24., 1993. Goiânia, Resumos expandidos. Campinas, Sociedade Brasileira de Ciência do Solo, 1993. p.183-184.         [ Links ]

WILLETT, I.R. & CUNNINGHAM, R.B. Influence of sorbed phosphate on the stability of ferric hydrous oxide under controlled pH and Eh conditions. Aust. J. Soil Res., 21:301-308, 1983.         [ Links ]

WILLETT, I.R. & HIGGINS, M.L. Phosphate sorption by reduced and reoxidized rice soils. Aust. J. Soil Res., 16:319-326, 1978.         [ Links ]

WILLETT, I.R.; MUIRHEAD, W.A. & HIGGINS, M.L. The effects of rice growing on soil phosphorus immobilization. Aust. Exp. Agric. Anim. Husb., 18:270-275, 1978.         [ Links ]

WILLETT, I.R .& HIGGINS, M.L. Phosphate sorption and extractable iron in soils during irrigated rice-upland crop rotations. Aust. Exp. Agric. Anim. Husb., 20:346-353, 1980.         [ Links ]

 

 

Recebido para publicação em novembro de 1996
Aprovado em maio de 1998

 

 

(1) Parte da Tese de Mestrado em Ciência do Solo do primeiro autor, apresentada à Universidade Federal do Rio Grande do Sul em agosto de 1996.

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