Assessing Two Types of Hydrogels on the Hydraulic Properties of a Sandy Loam Soil

Water scarcity poses a formidable challenge facing sustainable agriculture in arid and semi-arid regions. Therefore, the objective of the present study is to investigate the influence of two kinds of hydrogels (sodium polyacrylate, SAP, and polyacrylamide, CLP) on some of the hydraulic properties of a sandy loam soil utilizing the RETC program. By mixing either of the two hydrogels with the sandy loam soil using 0.0, 0.1, 0.2, and 0.3% (w/w), water holding capacity (WHS), normalized fraction of water retained (NFWR), specific amount of water retained (SWR), and saturated water increased significantly as the hydrogel rates increased. The SAP and CLP rates of 0.3% gave WHS of 0.49 and 0.46 g/g hydrogel-soil mixture, respectively. The saturated hydraulic conductivity (Ks) decreased significantly as the hydrogel rates increased. The CLP of 0.3% rate provided the lowest Ks (5.35x10-5 m/s) that result in low water-deep percolation. The RETC program described the soil water-desorption curves well for hydrogel-soil mixture rates of 0.0 (control) and 0.3%. The residual water, available water, air capacity, and air-entry suction of the hydrogel-treated soil increased in comparison to the control. The SAP treatment provided the greatest values for the aforementioned parameters. The available water is 3.2 and 2.3-fold that of the control for SAP and CLP treatments, respectively. Both SAP and CLP treatments enhanced the specific water capacities. Getting well knowledge with the interaction among absorbents and soil may result in an efficient and economical technology for enhancing the water management of a sandy loam soil.