Variation of enzyme activities, CO2 evolution and redox potential in an Eutric Histosol irrigated with wastewater and tap water

Abstract

An Eutric Histosol soil was irrigated for 4 years with municipal wastewater to compare its characteristics with a soil under natural rainfall that had never received wastewater and a soil that was irrigated with normal tap water. Four years irrigation of the soil with wastewater caused significant (P<0.001) increase in dehydrogenase, urease, acid and alkaline phosphate activities and CO2 evolution, and reduced the redox potential (P<0.05). The influence of treatments and plant cover on soil properties were significant (P<0.05) under both salix and grasses, except for few properties (redox potential and urease and alkaline phosphatase activities). It is suggested that, although different toxicants, e.g. heavy metals, may accumulate in wastewater-treated soils, enrichment of soil with organic substances and nutrients stimulated CO2 evolution and enzyme activities in the irrigated soil.