Clay minerals in some upland soils from Thailand

Mineralogy of red- and yellow-colored soils from Thailand

“…Such a clay mineraligical feature was essentially the same as that reported by OGAWA et al (1981) for similar soils from Thailand. Although the relative abundance of the major and accessory components varied slightly or appreciably from profile to profile, no makred difference of the composition was observed among the horizons in each profile.…”

Physicochemical properties of the soils associated with shifting cultivation in Northern Thailand with special reference to factors determining soil fertility

“…Clay mineral composition of the soils was characterized by various degrees of mixture of kaolin minerals and clay mica with, in some cases, a certain amount of 2: 1-2: 1 : 1 intergrade minerals. Compared to various upland soils in Thailand previously reported (Ogawa et al 1981;y oshinaga et al 1989), in which kaolin minerals generally predominated, the soils studied seemed relatively rich in 2: 1 clay minerals. Only two profiles out of 40, that is, DP-Cl and DP-F9, contained a significant amount of smectite.…”

Clay mineralogy of a Reddish Brown Lateritic soil from Thailand

“…The soil was relatively coarse-textured with 50-60% sand and with a relatively narrow range of textural classes (SC-SCL-LiC) through the profile. The soil has been described as having developed in a residuum derived from shale associated with limestone (Moormann and Rojanasoonthon cited in Ogawa et al 1981). If so, however, it would be expected to be much finer textured as are the soils of the Pak Chong series which have formed in this type of residuum (Soil Survey Division 1969-1980Yoshinaga et al 1989).…”