Soils of Bangladesh--1

Physiographic units: 

There are 23 physiographic units under 3 geomorphologic (geo-earth; morphi-form; logos-knowledge) division of Bangladesh soil-

             A. Flood Plain Areas (80% of the country)

             B. Terrace Areas (80% of the country)

             C. Hill Areas (12% of the country)

A.  Flood Plain Areas:

1)    Old Himalayan Piedmont Plain

2)    Teesta Flood Plain

3)    Karatoya-Bangali Flood Plain

4)    Lower Atrai Flood Plain

5)    Lower Purnabhaba Flood Plain

6)    Young Brahmaputra Flood Plain

7)    Old Brahmaputra Flood Plain

8)    Ganges River Flood Plain

9)    Ganges Tidal Flood Plain

10)          Gopalganj-Khulna Beels

11)          Arial Beels

12)          Middle Meghna Flood Plain

13)          Lower Meghna River Flood Plain

14)          Young Meghna  Estuarine Flood Plain

15)          Old Meghna Estuarine Flood Plain

16)          Surma-Kushiyara Flood Plain

17)          Sylet Basin

18)          Northern and Eastern Piedmont Plains

19)          Chittagong Coastal Plain

20)          St.Martin’s Island

B. Terrace Areas:

21)          Madhupur Tract

22)          Barind Tract

C. Hill Areas:

23)          Northern and Eastern Hills

General soil type: 

Types emphasis on the process of silt formation. A general soil type comprises a group of soils which have formed in the same way and which have a broadly similar appearance. A total of 21 general soil types have been recognized in Bangladesh. This classification is a non-technical grouping of soil.

General Soil Types		Diagnostic Properties
A. Flood Plain Soils:-
1.Non-calcareous Alluvium	Raw or stratified alluvium present within 25 cm from surface; not calcareous or sulphidic within 125 cm from surface.
2. Calcareous Alluvium	Similar to non-calcareous alluvium but calcareous throughout or within 125 cm from surface.
3. Acid Sulphate soils	Poorly or very poorly drained, grey or dark grey soils on tidal flood plains which are actually or potentially extremely acid (pH <>
4. Peat soil	Very poorly drained soils in which organic matters (peat or muck) comprises all or more than half of the upper 80 cm.
5. Non-calcareous Grey Flood Plain soils	Seasonally flooded soils developed to below 25 cm, dominantly grey in sub-soils, not very strongly acidic throughout the upper 50 cm and not calcareous within 125 cm from surface.
6. Calcareous Grey Flood Plain soils	Similar to non-calcareous grey flood plain but calcareous throughout or within 125 cm from surface.
7. Non-calcareous Dark Grey Flood Plain soils	Seasonally flooded soils developed to below 25 cm; not very strongly acidic throughout the upper 50 cm and not calcareous within 125 cm from surface.
8. Calcareous Dark Grey Flood Plain soils	Similar to non-calcareous dark grey flood plain soils, but calcareous throughout or within 125 cm from surface.
9. Grey Piedmont Soil	Imperfectly to poorly drained soils in piedmont alluvium developed to below 25 cm. Similar to non-calcareous grey flood plain soils but usually more prominently mottled and medium it strong acid in sub-soil.
10. Acid Basin Clays	Poorly or very poorly drained heavy clay developed to below 25 cm. Very strongly or extremely acid to below 50 cm but not sulphuric or sulphidic.
11. Non-calcareous Brown Flood Plain Soils	Similar to calcareous brown flood plain soils, but not calcareous within 125 cm from surface.
12. Calcareous Brown Flood Plain Soils	Moderately well to poorly drained flood plain soils developed to below 25 cm, prominently brown in sub-soil, calcareous throughout or within 125 cm from surface.
13. Black Terri Soils	Imperfectly to poorly drained soils in Himalayan piedmont alluvium with a very dark brown to black top soils >25 cm thick.
B. Hill Soils:-
14. Brown Hill Soil	Excessively to well drained hill soils, developed to below 25 cm; yellow brown to reddish brown sub-soil; usually very strongly acid throughout 125 cm from surface.
C. Terrace Soil:-
15. Shallow Red Brown Terrace Soils	Moderately well to imperfectly drained olive-yellow to strong brown soils over lying grey, Madhupur clay at 25-60 cm.
16. Deed Red Brown Terrace Soils	Well drained to moderately well drained red to yellow-brown soils, overlying a strongly red-mottled substratum.
17. Brown Mottled Terrace Soils	Imperfectly drained soils with a strongly mottled brown and red sub-soil, overlying a strongly red mottled substratum.
18.Shallow Grey Terrace Soils	Poorly drained, grey, silty soils overlying grey Madhuput clay at 20-30 cm.
19. Deep Grey Terrace Soils	Poorly drained, mainly silty soils with a grey mottled brown or red sub-soil, overlying a strongly red-mottled substratum.
20. Grey Valley Soils	Poorly drained, deep, grey, mainly silty soils occurring in terrace valleys.
Made Land:
21. Made Land	Soils on raised cultivation platforms; similar in color and texture to adjoining natural soils, but better drained and often darker and browner.

Bismark Bangali

BSC  in Agrotechnology 

 

 

 

Khulna University.