Phosphorus Analysis in High-Carbon Andosols: Method Adaptation for Challenging Soil Matrices

This 14-days on-site research praxis introduces students to the analytical challenges and methodological adaptations required for P analysis in high-carbon Andosol-type soils. These soils show high organic matter content, intense dark coloration and rapid anion sorption, which can interfere with conventional colourimetric and extraction-based methods.

Students will work with Amazonian Andosol samples and learn how to prepare, pre-treat and re-incubate dried soils prior to analysis. In the laboratory, they will apply adapted protocols for phosphomonoesterase activity and modified P fractionation, with particular attention to controls, limitations and interpretation of each method.

The praxis integrates laboratory work, methodological reflection, data evaluation and scientific communication. Students will document their workflow, manage relevant literature, analyse and visualize results, and present their findings in a concise scientific report and short oral presentation.

General learning outcomes

• Explain the analytical challenges associated with high-carbon Andosol-type soils, including high organic matter content, dark coloration, and rapid anion sorption.
• Prepare and pre-treat soil samples for P and enzyme analysis, including controlled re-incubation of dried samples.
• Apply adapted protocols for phosphomonoesterase activity analysis and evaluate methodological limitations.
• Conduct and interpret a modified Hedley P fractionation to assess different P pools.
• Communicate results in a short scientific report and oral presentation.