MINERALOGY OF SOILS FROM DIFFERENT AGROECOLOGICAL REGIONS OF BANGLADESH: REGION 3-TISTA MEANDER FLOODPLAIN

Bangladesh has been divided into 30 Agroecological Regions (AEZs) and the applied agricultural research has currently been conducted on this basis. In context of the lack of enough information on mineralogy on the AEZ basis, an attempt has been taken to study on the mineralogy of important soils from all AEZs of Bangladesh in order to provide basic information for applied research. As a part of this attempt, the mineralogy of soils from ten representative soil series of AEZ 3, Tista Meander Floodplain, has been reported in this paper. The clay content of the surface soils ranged from 11.5 to 22.1% and the texture was mostly silt loam. The 2-20 pm fraction was found to dominate over other fractions in all soils. This fraction was composed mainly of quartz, followed by mica, chlorite and plagioclase. The <2 ƒÊm clay fraction was dominated by mica and chlorite and in most cases by the interstratified mineral of mica and chlorite. These minerals were supposed to be inherited from the parent material of metamorphic rocks derived from the Himalayans. The impact of mineralogy on the inherent potentiality of soils regarding crop production has been discussed.