Impacts of municipal wastewater effluent on seed banks, chemistry, and microorganisms of soils excavated from wetland impoundments designated for wildlife

After seven years of irrigation with either municipal wastewater effluent (WWE) or Missouri River water (MOR), wetland impoundments were examined for changes in and distribution of electrical conductivity (EC) and pH in soils. These commonly used soil quality indicators reveal conditions important for several ecological processes. The normal pool elevation of the WWE-irrigated impoundment showed significantly greater EC and lower pH than the flood elevation and the impoundment irrigated with MOR. The significant changes in EC and pH in the WWE-irrigated impoundment are attributed to greater electrolyte, organic matter, and ammonium concentrations in the WWE compared to MOR. However, soil properties and watermanagement of the impoundments may have contributed to changes in these soil parameters. Soil properties such as exchange capacity, texture, and drainage in concurrence with the hydrology of the impoundment can affect distribution of soil salinity and pH. Continuous irrigation with WWE may increase salinity and decrease pH to a point that alters soils, seed banks, vegetation, and other biotic communities of wetlands.