The effects of quality of irrigation water on selected soil physical properties in rice cultivation lands (Oryza Sativa)

Growing population and increasing industrial and agricultural activities and successive droughts have caused more attention to soil and water conservation. To achieve this propose using wastewater for irrigating agricultural lands increased in recent decades. This study aimed investigating the effects of wastewater including municipal، industrial wastewater and river water on some soil physical characteristics. This research done in the area of agricultural lands located in the city Lenjan Zarrin Shahr. The lands area that have the same parent material and irrigated with municipal and industrial wastewaters (each for 8 years) and river water (20 years) where were selected for treatment. After detailed analysis for each of the treatments listed in 4 replications and tests were used to predict and physical properties include were measured. The result showed that irrigation with municipal and industrial wastewaters increased the bulk density 1. 3 g/cm3 (in river water treatment) to 1. 63 and 1. 76 g/cm3. Irrigation with this wastewaters caused increase in aggregate stability to 0. 67 and 0. 69 mm in municipal and industrial wastewaters compare to river water (0. 27 mm). Decreasing the saturation soil hydraulic conductivity and infiltration and bimodal retention curve were other soil physical properties reactions to using municipal and industrial wastewaters. The result showed that irrigation with wastewater had negative effect on physical properties and caused change in particle size distribution and recommended that monitored effect of long-term using of wastewater on physical properties.