Evaluation of Physical Characteristic of Sandy Soil, the Effects of Amendments Using Comsol Multiphysics and Laboratory Experiments.

Abstract

Information on soil water retention and hydraulic properties is paramount for assessing soil properties and modeling movement of water in the soil. This research aims at investigating soil amendments (zeolite, activated charcoal, and rice hush ash) impacts on water retention, physical properties, and hydraulic properties of sandy soil. To assess the changes in water content of sandy soil due to the soil amendments, retention curve of water tests were carried out using both simulation and experimental methods. The results of the water retention tests showed an increase of water content and a decrease in the hydraulic properties (hydraulic conductivity) of sandy soil. Simulation results using the COMSOL Multiphysics model also shows similar trend as water retention increase and a decrease in hydraulic conductivity with rice husk ash, zeolite, and activated charcoal applications respectively. The results confirmed that the COMSOL Multiphysics model gave accurate simulation results in comparison with the experiments. These results suggest there are numerous benefits of adding soil amendments to sandy soil in relation to increasing the retention of water and decreasing hydraulic conductivity. This study also shows that zeolites, rice husk ash and activated charcoal improve the water content level in sandy soils, thus controlling water losses. Therefore, rice husk ash, zeolite, and activated charcoal addition to sandy soil is an effective way to improve plants soil in drought areas.