Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Mineralogical Characterization of Clay Fraction of Chalan Beel Soils of Bangladesh

A.B.M.S. Islam
Department of Soil Science, Patuakhali Science and Technology University, Dumki, Patuakhali–8602

M.S. Hussain
Department of Soil, Water and Environment, University of Dhaka, Dhaka-1000

Abstract/ Executive Summary:

Top soils of four different series viz Jaonia (Typic Haplaquept), Halti (Typic Haplaquept), Taras (Aeric Haplaquept) and Digli (Typic Haplaquept) developed on Atrai river alluvium were studied to investigate the clay mineralogical composition. X-ray diffraction technique was employed to identify and quantify the minerals. The XRD patterns were obtained with Ni-filter Cu kα - radiation at a scanning speed of 2º2θ min and the amount of minerals was estimated by XRD peak intensities at parallel powder mount. Mica was the dominant clay mineral (33 - 51%) in all soils, followed by quartz (13 -19%). The kaolinite contents were small (8 - 10%) over the soils. The occurrence of vermiculite in the Digli and Taras soils (9 and 7% respectively) indicates a considerable transformation of mica. There is very little or no smectite minerals in the soils which might be due to poor parent material and disappearance of smectite from the top soils. Appreciable amount of primary minerals like quartz and feldspars have also been observed in the clay fraction of the soils.

Keywords: Clay minerals, Chalan beel, X-ray diffraction

Location: Chalan Beel area of Bangladesh

Start Date: 00-00-2008

End Date: 00-00-2008

Program Area: Crop-Soil-Water Management

Commodity: Soil fertility

Objectives:

1. The properties of soils of an area vary greatly with the content and properties of clay minerals. Moreover, the availability of soil nutrients depends significantly on clay minerals persist in the respective soils of the concerned area. From this point of view, determination of clay minerals along with their quantification in the soils of Chalan Beel were investigated for detailed characterization.

Methodology:

Study area - The soil samples were collected from the Chalan Beel area of Bangladesh between 24⁰05′ to 24⁰35′ north latitude and 89⁰ to 89⁰35′ east longitude located in singra Upazila of Natore district. Soils - Four soil series from different locations of Lower Atrai Basin were selected for the study. GPS was used to locate the position of the sites from where top soil samples (Ap1) were collected. Separation of clay fraction - 10g of air dry soil was treated with 30% H2O2 heated for about 2h to decompose organic matter. Excess H₂O₂ was removed by centrifugation by washing 3 times with water and 3m Nacl was added each time to prevent defluculation of clay particles and the supernatant was discarded by decantation. The pH of the soil suspension was adjusted to 10 by addition of 1N NaOH. Clay fraction (< 2 μm) was separated by repeated sedimentation-siphoning method. Mineralogical analysis - Identification and estimation of mineralogical composition were carried out by X-ray diffraction (XRD). The separated clay fraction was treated by 1M KCl and 0.5N MgCl₂ respectively to make K+ and Mg+ saturated clay and washed them with ethanol to remove excess salts. An amount of 0.4 ml solution was dropped on a glass slide covering two third of its area, air dried, and X-rayed (parallel powder mount). In addition to the air-dry specimen, the Mg-saturated clay was X-rayed after saturation with glycerol; and K- saturated clay after heating at 300ºC and 550ºC for two hours. The XRD patterns were obtained using Shimarzu XRD6000 diffractometer with Ni-filtered Cu kα- radiation at 40 kV and 30 mA at a scanning speed of 2.0º/min over a range of 3-35º2θ. Approximate mineral contents of clay fraction were estimated on the basis of the relative peak intensities in the XRD patterns. The intensities ratio of two components P and Q in a multi-component mixture can be related to their weight ratio as follows: Ip/Iq = Kp.q Wp/Wq Where Ip and Iq are the intensities of the P and Q components in XRD, Wp and Wq are the weight proportion of P and Q components and Kp.q a constant value, is the intensity-weight coefficient of P and Q components. Reflection of the Mg-saturated and glycerol solvent specimen were mainly used to calculate the amount of different minerals.

Source of Information: J. Bangladesh Agril. Univ. 6(2): 253–260, 2008; ISSN 1810-3030

Article Link (Online Journal):

Funding Source:

Total Budget (Tk.) :

Achievement/Findings:

The XRD patterns were obtained with Ni-filter Cu kα - radiation at a scanning speed of 2º2θ min and the amount of minerals was estimated by XRD peak intensities at parallel powder mount. Mica was the dominant clay mineral (33 - 51%) in all soils, followed by quartz (13 -19%). The kaolinite contents were small (8 - 10%) over the soils. The occurrence of vermiculite in the Digli and Taras soils (9 and 7% respectively) indicates a considerable transformation of mica. There is very little or no smectite minerals in the soils which might be due to poor parent material and disappearance of smectite from the top soils. Appreciable amount of primary minerals like quartz and feldspars have also been observed in the clay fraction of the soils.

Knowledge Management: Journal