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Complexation du Ca++ par les substances humiques extraites de tourbe naturelle et de tourbe traitée aux oxydes d'azote

Kaemmerer, Michel and Guiresse, Agnès Maritchù and Hafidi, Mohamed and Brun, G. and Seibane, Lydie and Revel, Jean-Claude Complexation du Ca++ par les substances humiques extraites de tourbe naturelle et de tourbe traitée aux oxydes d'azote. (1999) Agrochimica, 42 (1). 38-45. ISSN 0002-1857

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Abstract

The study of the complexation of calcium by humic substances (SH) extracted from a natural peat (TN) and from a peat treated with nitrogen oxides (TT) was followed by conductimetry and potentiometry with pH variable and pH constant. The complexing capacity increases as the pH rises: complexed calcium is 130 cmol kg*[-1) SH (TN) and 135 cmol kg*[-1) SH (TT) with pH 5, and 330 cmol kg*[-1) SH (TN) and 410 cmol kg*[-1) SH (TT) with pH 9. These reactions involve various functional groupings of pKa1 < 4 for TN and TT, pKa2 = 5.9 for TN and pKa2 = 6.2 for TT; in all cases, the medium has exhibited an increase in acidity. The complexation of calcium by HS extracted from TT could then enhance the efficiency of the phosphatic nutrition of plants.

Item Type:Article
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:Université de Toulouse > Institut National Polytechnique de Toulouse - INPT (FRANCE)
Other partners > University of Cadi Ayyad - UCAM (MOROCCO)
Laboratory name:
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Deposited By: Sandra BARON
Deposited On:31 Aug 2017 08:12

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