Flooded Soils

From MicrobeWiki, the student-edited microbiology resource
Revision as of 06:32, 6 March 2008 by Jokang (talk | contribs)
Jump to: navigation, search

Introduction

When the pore space in soils are saturated with water, oxygen dissolved in water is gradually depleted because oxygen is used as terminal electron acceptor for repiration by some aerobes and the facultative anaerobes. This results in anaerobic condition of soils. This anoxic condition can be found in soil aggregates and polutants plume. Under anoxic condition, some microbes can use alternative electron acceptors such as nitrate, iron, sulfate, and carbon dioxide.

Process

general process

aggregates/polutant plume

Oxidation/reduction(redox) reaction

Electron tower

Change of terminal electrons acceptor with soil depth

Variation of pH and Eh

pH

gradually increasing due to consumpsion of H+ during ananerobic respiration

Eh

decreasing in Eh(V) with soil depth

Exchange of atmospheric gases

Oxygen

Carbon dioxide

Nitrogen

Methane

Solubility/mobility of mineral

Effects on life

Plant nutrient availability

Microorganism activity

WHAT ABOUT IRON AND MANGANESE?-Kate

Key Microorganisms

The role of micoorganisms under flooded soil

nitrate reducing bacteria

Methaneous bacteria

Ion reducing bacteria

Sulfate reducing bacteria

Manganese reducing bacteria

Current Research

References

Edits and Dates

Edited by students of Kate Scow