In salt affected area of Phra Yun, chemical geo-textile was installed at 20 cm deep from soil surface in
the ridge of 40 cm high in December 2002, and then soils were sampled above and below the geo-textile in
March 2004 to analyze water content and EC1:5 values. As shown in Figure 6, water content above the
geo-textile was lower than that below the geo-textile, however EC1:5 values above the geo-textile were
higher than that below the geo-textile.
In addition, there was a tendency for EC1:5 values in the upper parts of the ridges above the geo-textile
to be higher than that without the geo-textile. It meant that rainfall events from January 2003 to February
2004 did not contribute well for leaching sodium components out from top layer of the ridges. Although
soil texture was sandy in salt affected area of Phra Yun, the soil showed low permeability as shown in
Table 2. It was considered that soil permeability improvement is indispensable for leaching sodium
components effectively.