ارزيابي اثر كاربرد پليمرهاي ابرجاذب بر ظرفيت نگهداشت و پتانسيل آب بر سه نوع بافت خاك

Evaluating the Application of Superabsorbent Polymers on Soil Water Capacity and Potential on Three Soil Textures

Superabsorbent polymers can help to improve soil conditions by collecting and storing rain water and irrigation water that would be otherwise lost due to gravity and/or run-off due to their water retention properties. This phenomenon enhances the irrigation efficiency particularly in arid and semi-arid regions of the world. The objective of this study was to evaluate the application of superabsorbent polymers on soil water capacity and soil moisture characteristic curve. Two computer models, RETC and Rosetta, were used for analysis. The RETC program used the parametric models of Brooks-Corey and van Genuchten to represent the soil water retention curve, and the Rosetta used the van Genuchten model based on neural networks. Two polymers, PR3005A and Super AB A100 in four levels, 2, 4, 6 and 8 g/kg were mixed with three soil textures, sandy, loamy and clay. The result of the soil moisture characteristic mod-els showed that for each texture, superabsorbent polymers caused increase of the residual water content (Teta r), saturat-ed water content (9S), and soil moisture gradient curve. Air entry value, hb = 1/(Alfa), increased in sandy soil, but decreased in the other soils. The result of the statistical analyses showed that there was a significant difference between samples containing polymers and the control (without polymer), between level of polymer application and the type of polymers. The plant available water increased from 1.5 to 3.5 with superabsorbent polymers in two levels, 6 and 8 g/kg. Also soil capillary porosity increased, particularly in the sandy soil.