| Registro completo |
| Provedor de dados: |
Rev. Bras. Ciênc. Solo
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| País: |
Brazil
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| Título: |
Activity of phosphorus of synthetic Fe-K-P compounds in superphosphate fertilizers as affected by pH and ionic strength
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| Autores: |
Prochnow,Luís Ignácio
Biasioli,Gustavo Marques
Rodella,Arnaldo Antonio
Jesus,Sérgio Luís de
Montes,Célia Regina
Alleoni,Luís Reynaldo Ferracciú
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| Data: |
2006-06-01
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| Ano: |
2006
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| Palavras-chave: |
Phosphate fertilizers
Cationic impurities
Phosphorus activity
Phosphorus bioavailability
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| Resumo: |
The concentration of orthophosphate ions released from Fe-K-P compounds (Fe3KH8(PO4)6 .6H2O and Fe3KH14(PO4)8 .4H2O) present in superphosphates increases with pH, which initially suggests that the agronomic effectiveness of P fertilizers containing high amounts of these compounds would also increase with soil pH but studies considering activity, instead of concentration, are necessary. With this purpose, both compounds were synthesized under laboratory conditions, characterized by elemental chemical analysis, optical microscopy, X ray diffractometry, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), and used in a solubility study. Solutions of 0.01, 0.05 and 0.1 mol L-1 NaCl with pH adjusted to 3.0, 4.0, 5.0, 5.5, 6.0, 6.5, 7.0 and 7.5 were prepared for the solubility study of H8-syn, H14-syn and a phosphate rock (PR) from Brazil. The orthophosphate activity as H2PO4- and HPO4(2-) was calculated in each situation as related to pH and ionic strength using software MINTEQ. The remaining precipitates after equilibrium were chemically analyzed and subjected to X ray, SEM and EDS. Results of chemical analysis and instrumental techniques confirmed the preparation method. The activity of orthophosphate ions of both compounds tended to decrease under increasing pH and/or ionic strength of the solution, which in turn suggests that an increase in the solution pH does not necessarily promote an increase in the P bioavailability for plant uptake. This can be important when evaluating agronomic data of P fertilizers with high contents of these two Fe-K-P compounds.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832006000300008
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| Editor: |
Sociedade Brasileira de Ciência do Solo
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| Relação: |
10.1590/S0100-06832006000300008
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| Formato: |
text/html
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| Fonte: |
Revista Brasileira de Ciência do Solo v.30 n.3 2006
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| Direitos: |
info:eu-repo/semantics/openAccess
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