Effects of raw municipal wastewater on soil physical quality and biological yield of Wheat (Case study: Harsin)

The present study was done to investigate a few decades application of raw municipal wastewater on soil physical quality and biological yield of wheat in Harsin. In this way, the main soil physical properties, which effect on soil physical quality, and total concentrations of some heavy metals in the soils of ten sites, that have been irrigated by wells water or wastewater, were statically analysed. The results showed that the use of wastewater, while added organic matter to the soil, improved aggregate stability, reduced soil bulk density, and increased other soil physical properties, including: saturated hydraulic conductivity, total porosity and saturation percentage. The total concentrations of Zn and Fe in the lands that had been irrigated by wastewater were significantly more than in the lands had been irrigated by wells water, while, concentrations of Cr, Pb and Ni were not significantly different. In general, application of wastewater improved the soil physical quality and meanwhile increased biological yield of wheat in the study area.