عنوان مقاله [English]
Nowadays, the use of polymers and soil and water reclamation agents has a significant bearing on agriculture. Polyacrylamide is one of the most important polymers that reduces soil erosion and increases water penetration in the soil by the PAM brand. Research on the effect of using PAM on soil physical properties (such as saturated hydraulic conductivity) has not had the same results. In this study the effect of six concentrations 0, 5, 10, 15, 20, 25and 30 mg/l dissolved PAM on saturate hydraulic conductivity 3 different soil textures (sandy loam, loam and silty clay loam) were studied in laboratory. Saturation hydraulic conductivity was measured with constant head method. For each treatment five replications were considered. Results showed that PAM viscosity increased about 1.9 % relative to water for each mg/l increase in PAM concentration. In sandy loam soil, with increasing PAM concentration, the hydraulic conductivity of soil saturation decreased linearly and significantly. With increasing of 5 mg / l of PAM solution, the hydraulic conductivity of sandy loam soil 2.6 cm / h decreased. In sandy loam soil, the effect of increasing the viscosity of PAM solution passing through the porous medium was more evident than the effect of the bond between clay and PAM particles. In loamy and silty clay loam soil texture, the trend of saturation hydraulic conductivity changes was compared to the PAM concentration as a parabolic curve. In the loam soils up to 20 mg / l PAM concentration and in the silty clay loam soil up to 25 mg / l PAM, the hydraulic conductivity of soil saturation increased and in concentrations greater than these values, the saturated hydraulic conductivity decreased. For loam soil and silty clay loam with increasing concentration of PAM solution to the optimum amount, the effect of bond between clay and PAM particles and later on the effect of viscosity PAM solution was evident.