“…50 have been suggested for different types of soils in numerous studies (e.g. Chung et al, 2007;Jardine and Hight, 1987;Karlsson and Viberg, 1967;Kim et al, 2009;Ladd, 1991;Larsson, 1980;Mayne, 1980;Mayne and Mitchell, 1988;Nicholson and Jardine, 1981;Shibuya et al, 2008;Suzuki and Yasuhara, 2007;Tanaka, 1994;Watabe et al, 2002). From these studies it can be concluded that the s u =ó 9 p ratio varies with soil type.…”