[A-GE27] Subsurface Mass Transport and Environmental Assessment

[AGE27-P07] Natural rubber latex application to sandy loam in Thailand to improve the permeability and water holding capacity

*Yasushi Mori¹, Ryohei Otsuki¹, Hiroaki Somura¹, Jun Kano², mamoru matsushima³, Bnaja Junhasavasdikul⁴ (1.Graduate School of Environmental and Life Science, Okayama University, 2.Graduate School of Natural Science and Technology, Okayama University, 3.UEDA BRAKE Co., Ltd., 4.Rubber division of the Polymer Society of Thailand)

Keywords:Thailand, Red soil, latex, soil aggregation, soil erosion

In Thailand, red soils degraded by strong sunlight are widespread and at risk of being washed away by heavy rainfall. Polyvinyl alcohol and polyacrylamide have been used to prevent soil erosion, but these are artificial industrial materials and sustainability is a problem. On the other hand, Thailand produces natural rubber latex, which is used as rubber, but there is a problem of where to dispose of the surplus. We applied natural rubber latex to red soil to enhance the aggregation and subsequent permeability and water retention by the viscosity of the latex. As a result, aggregation occurred at a mixing rate of about 0.1%, and the water holding capacity in the high-moisture area increased, which was also confirmed by particle size analysis. Although there was little difference in infiltration capacity, when exposed to evaporation, the latex-modified soil retained water in the lower part of the soil due to water loss only in the upper layer, followed by evaporation interception. It is considered that the formation of the soil aggregates caused evaporation and evaporation interception only in the upper layer, thus preserving the moisture in the lower layer.