Page 71 - E-BOOK English

The representatives of Fluvisols in Thailand

Eutric Fluvisols

Eutric Fluvisols have an effective base

saturation [exchangeable (Ca + Mg + K + Na) /Exchangeable
(Ca + Mg + K + Na + Al); exchangeable bases by

1 M NH OAc (pH 7), exchangeable Al by 1 M KCl
4
(unbuffered)] of ≥ 50% in the major part between 20
and 100 cm from the mineral surface soil.

Chiang Mai series (Cm) is a representative

of Eutric Fluvisols. Chiang Mai soils are formed from
recent alluvium and occur on the higher parts of the
river and stream levee, mostly found in the North of

Thailand. Relief is level to nearly level with locally an
undulating micro-relief. Slopes range from 0-3

percent. Drainage is moderately well drained.
Permeability is moderate and surface runoff is slow.
They are very deep and stratified soils and characterized

by a brown or grayish brown or dark brown loam, silt
loam or sandy loam A horizon overlying a brown or
yellowish brown or dark yellowish brown loam, silty

clay loam or sandy loam C horizon. Textures of the
subsoil are variable, with such stratification but fall in
the loamy particle size class in the control section.

Faint or distinct mottles usually occur in the subsoil.
Soil pH is moderately acid to neutral (pH 6.0-7.0). All

horizons contain abundant mica flakes. Rainy season
flood is one problem that should be considered before
planting. However, in the irrigated area can be

cultivated with fertilizer application for higher yield.

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