Organic acids in the rhizosphere and phytoavailability of sewage sludge-borne trace elements

Pesquisa Agropecuária Brasileira

Adriana Marlene Moreno Pires²  Giuliano Marchi¹  Maria Emília Mattiazzo¹  Luiz Roberto Guimarães Guilherme¹ 

[1] ,Embrapa Meio AmbienteJaguariúna SP ,Brazil

关键词: biosolid;    exudates;    heavy metals;    availability;    biossólido;    exsudatos;    metais pesados;    disponibilidade;   

DOI  :  10.1590/S0100-204X2007000700002

来源: SciELO

【 摘 要 】

The aim of this work was to quantify low molecular weight organic acids in the rhizosphere of plants grown in a sewage sludge-treated media, and to assess the correlation between the release of the acids and the concentrations of trace-elements in the shoots of the plants. The species utilized in the experiment were cultivated in sand and sewage sludge-treated sand. The acetic, citric, lactic, and oxalic acids, were identified and quantified by high performance liquid chromatography in samples collected from a hydroponics system. Averages obtained from each treatment, concentration of trace elements in shoots and concentration of organic acids in the rhizosphere, were compared by Tukey test, at 5% of probability. Linear correlation analysis was applied to verify an association between the concentrations of organic acids and of trace elements. The average composition of organic acids for all plants was: 43.2, 31.1, 20.4 and 5.3% for acetic, citric, lactic, and oxalic acids, respectively. All organic acids evaluated, except for the citric acid, showed a close statistical agreement with the concentrations of Cd, Cu, Ni, and Zn found in the shoots. There is a positive relationship between organic acids present in the rhizosphere and trace element phytoavailability.

【 授权许可】

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