Page 101 - E-BOOK English

Leptosols

Definition

Leptosols comprise very thin soils above continuous rock and soils that are rich in coarse

fragments, thereby mostly common in mountainous areas. These soils are found with continuous
rocks or technic hard materials within 25 cm from the surface soil. The fine earth of Leptosols
is generally less than 20 percent by volume and found over at the depth of 75 cm from the
surface or at where either hard rock or technic hard material is presented shallower.

Distribution

Leptosols are found worldwide with a total area of 10,343 million rais, typically common

in mountainous areas and deserts.
In Thailand, Leptosols cover 8.65 million rais, randomly distributing in small areas
throughout the country. They are mostly found on steep sloping areas of the north, central,
northeast and south of Thailand.

Formation

Leptosols are regarded as low development soils without a distinct horizon. These
soils tend to develop on hard rocks that are resistant to be weathered. The soil processes

that influence the formation of Leptosols are not sufficient to create any distinctive feature in
the soil.

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