Effect of Treated Wastewater Irrigation on Plant Growth and Biological Activity in Three Soil Types

Abstract

The effects of two types of treated wastewater on soil biological activity were studied in a pot experiment. Four irrigation treatments were tested on both soils sown with barley and unsown soils: distilled water (DW), half-strength Hoagland nutrient solution (NS), treated wastewater from a conventional treatment plant (CWW), and treated wastewater from a lagoon (LWW). Three types of soils were used: Chromic Luvisol, Calcaric Regosol, and Calcaric Arenosol. The greatest barley production was obtained under NS treatment in the three soils, whereas the least was produced by the DW treatment. Soil biological activity was strongly correlated to plant production, whereas no effect of treated wastewater irrigation was observed in the unsown soils. The greatest soil biological activity was found in the Luvisol. In conclusion, both soil type and the presence of plant root systems were found to have more influence on soil biological activity than irrigation water type.

Keywords:

• Barley rhizosphere
• enzymatic activities
• microbial biomass
• plant mineral content
• soil type
• wastewater irrigation

Acknowledgments

The authors thank Elena Baraza for constructive review and Keith Macmillan for the English language revisions.