| Acid Soil type of soil
in which the quantity of free H+ ions is higher than that of alkali or
alkaline earth cations. The pH is therefore less than 7.0. However, the
term 'neutral' is generally used for a soil with pH between 6.6 and 7.3.
Acid soils therefore have a pH less than 6.6. This means that it is more
acidic, which results from the presence of exchangeable hydrogen and aluminium
ions. The salt contents of this soil are composed predominantly of aluminium
sulphate and ferrous sulphate. The sources of hydrogen cations in soil
solution could be from acidic parent
materials, plant roots, humus,
carbon dioxide, alumino-silicate, iron pyrites, use of ammonium fertilisers
and sulphur too. Most of the soils of Bangladesh are low to medium acid
in reaction, due to the predominance of high rainfall areas and leaching.
There are mainly three groups of acid soils found in Bangladesh, such
as: acid
basin clay, acid
sulphate soil and brown
hill soil.
[Md Khurshid Alam]
|
