Abstract
One of the most prospective measures to solve the global warming problem is afforestation of desert, leading to the fixation of carbon dioxide from the atmosphere into the plant organic materials. The poor vegetation in desert is formed due to the higher potential evaporation than precipitation and shortage of water. It has been proposed that the permeability and water retention should be improved with various kinds of water retainers mixed with original soil. In the present study, the mixing effects of water retainers, peat, SAP (super absorbent polymer) and bauxite, to the Toyoura sand on permeability and water retention were evaluated. Permeability was reduced and water retention for water potential less than-101.8cmH2O (pF>1.8) was improved in all of experiment, especially by mixing peat under the present experimental condition. The water retention of the calcinated bauxite for water potential less than-105.0cmH2O (pF>5.0), which corresponds to high dryness resistance region was found.
