Changes in soil physical properties after irrigation of two forested soils with municipal wasterwater Journal Paper
- Author
- Magesan, G.N.
- Year
- 2001
- Journal / Source
- New Zealand Journal of Forestry Science
- Volume
- 31
- Number
- 2
- Pages
- 188-195
- Keywords
- municipal wastewater, soil physical properties, irrigation; volcanic soil, sand dune soil
- Summary
- Land application of wastewater in New Zealand is becoming more common due to resource management legislation and the cultural preferences of the indigenous people. Impacts of municipal wastewater irrigation on some physical properties of two sandy soils under Pinus radiata D. Don forest were measured on a site of sand-dune origin (Waitarere) and one of volcanic origin (Whakarewarewa) which received primarytreated and tertiary-treated wastewater, respectively, at a rate of 60 mm/week. Intact soil cores were collected at 0-100 mm and 100-200 mm from wastewater-irrigated and nonirrigated control sites after 4 years of irrigation. Atthe Waitarere site, irrigationwith primary-treated wastewater significantly decreased the bulk and particle densities and unsaturated hydraulic conductivity, but increased total porosity and macroporosity. However, there was no change in saturated hydraulic conductivity. At the Whakarewarewa site, irrigation with tertiary-treated wastewater did not change bulk and particle densities, total porosity, water retention, and hydraulic conductivity but significantly increased soil macroporosity. Wastewater quality and, possibly, soil origin appear to play important roles in the changes in soil physical properties observed under wastewater irrigation.