Journal article

Model organic compounds differ in their effects on pH changes of two soils differing in initial pH

Fatima Rukshana, Clayton R Butterly, Jeff A Baldock, Caixian Tang



The mechanisms by which organic materials affect soil pH are not fully understood. This study for the first time compared the short-term effect of various model organic compounds on pH change of two soils differing in initial pH (Podosol of pH 4.4 and Tenosol of pH 6.1). Eight organic compounds, representing common compounds in plant residues, were selected based on the number and type of chemical functional groups. The addition of organic acids (acetic, malic, citric, and benzoic acid) reduced soil pH immediately due to H⁺ dissociation. The magnitude of pH decrease depended on the rate of application, degree of dissociation of the acids, and initial soil pH. During a subsequent incubation, ..

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University of Melbourne Researchers


Awarded by Australian Research Council

Awarded by National Natural Science Foundation of China

Funding Acknowledgements

This work was supported by the Australian Research Council (Discovery project DP0877882) and the National Natural Science Foundation of China (40728001). We are grateful to Dr. Helen Hayden for reviewing the manuscript and Ms. Giang Nguyen (Jenny) for technical assistance.