Soil redox dynamics under dynamic hydrologic regimes - A review

Area of Science:

• Soil Science
• Environmental Science
• Biogeochemistry

Background:

• Electron transfer reactions mediated by soil microbiota are crucial for elemental cycling and soil redox potential (E_h).
• Understanding soil redox processes enhances soil health management and characterization of biogeochemical cycling.
• Redox state influences the reactivity, mobility, and toxicity of soil chemical species.

Purpose of the Study:

• To review studies on soil redox dynamics, focusing on dynamic hydrologic regimes.
• To identify knowledge gaps and suggest future research directions in soil redox dynamics.
• To synthesize current understanding of redox-sensitive species, microbial interactions, and hydrologic influences.

Main Methods:

• Literature review of soil redox dynamics under various hydrologic conditions, with emphasis on dynamic regimes.
• Analysis of the role of soil redox conditions on elemental cycling (carbon, nitrogen, phosphorus, metals, contaminants).
• Examination of microbial activity, biomolecular methods, and experimental setups for studying soil redox.

Main Results:

• Soil hydrology is a dominant driver of soil E_h, creating complex spatial and temporal distributions.
• Dynamic hydrologic regimes significantly impact chemical species cycling and microbial dynamics.
• Current research highlights knowledge gaps in deep subsurface fluctuating conditions and biomolecular tool application beyond nitrogen cycling.

Conclusions:

• Further research is needed on deep subsurface redox dynamics under fluctuating conditions.
• Expanding biomolecular tools to study diverse soil biogeochemical processes is essential.
• Enhanced field measurements and alternative experimental setups are required for comprehensive soil redox studies.