Noncontinuous Development of Reducing Conditions in Wetland Soils

Abstract

Soil aeration status in relation to water table was analyzed by contour mapping in a forested wetland, an emergent marsh, and an irrigated rice field. Two soil aeration status indicators, oxygen (O₂) and redox potential (Eh), showed a significant correlation (P<0.01). Soil O₂ and Eh levels generally decreased with the water table rise in the forested wetland and marsh, but with a noncontinuous pattern. The results indicate that soil aeration status could be temporally improved at an optimum water table level, probably due to O₂ transport by wetland plants. The soil Eh in the rice fields clearly showed a seasonal pattern regardless of the water tables.

Keywords:

• Oxygen
• redox potential
• water table
• wetlands