Short-Term Impacts of Gray Water Irrigation on Soil Characteristics in Land-Treatment Vegetation Filters

Abstract

This study on soil quality parameters was conducted from December 2008 to July 2010 to see the short-term impacts of gray water irrigation on physical and chemical properties of soil. The results envisaged slight positive impacts of wastewater irrigation on upper soil layers (0–30 cm) with an increase in soil organic matter (SOM) from 1.45% to 1.89% and nutrient content increases from 199 to 267 kg ha⁻¹ nitrogen (N), from 12.4 to 27.1 kg ha⁻¹ phosphorus (P), and from 131 to 136 kg ha⁻¹ potassium (K). Slight changes were also recorded in the soil pH and electrical conductivity (EC), which increased from 6.39 to 6.81 and 145 to 229 μS cm⁻¹ respectively, in the upper soil layers. The soil bulk density (BD) slightly decreased to 1.34 g cm³ in the treatment plot from 1.45 g cm³ at the commencement of the trial, which indicates good soil conditioning under the gray water irrigation trial.

Keywords:

• Bulk density
• gray water
• short-term impacts
• soil organic matter