Page 39 - E-BOOK English

การจำาแนกดิน (Soil classification)

WRB: Skeltic Acrisols
Soil taxonomy: Clayey-skeletal, kaolinitic, isohyperthermic Typic Kandiustults

Soil series: Chiang Khan series (Ch)

Profile description

 0-5 cm (Ac) Brown to dark brown (7.5YR 4/4)
gravelly clay loam; weak fine and medium

granular structures; friable, slightly sticky,
slightly plastic; many fine and few medium
roots; gravels composed of laterite and
some quartz diameter 2-3 mm about

25-35% of soil matrix; moderately acid (field
pH 6.0); gradual, smooth boundary.

 5-14 cm (ABc) Strong brown (7.5YR 4/6)
very gravelly clay loam; weak to moderate
fine and medium subangular blocky

structures; friable, slightly sticky, slightly
plastic; few medium and one large roots;
gravels composed of pseudolaterite 40-60%
of soil matrix; strongly acid (field pH 5.5);

mostly gradual, smooth boundary.

 14-35 cm (Btc1) Yellowish red (5YR 4/6) very
gravelly clay; moderate fine and medium
subangular blocky structures; firm, sticky,
plastic; patchy thin clay coating on ped and

gravel faces; common medium roots; gravels mostly composed of pseudolaterite about 40-60%
of soil matrix; strongly acid (field pH 5.5) gradual, smooth boundary.

 35-71 cm (Btc2) Yellowish red (5YR 4/6) gravelly clay; moderate fine and medium subangular
blocky structures; firm, sticky, plastic; moderately thick clay coating on gravels faces; common
medium roots; gravels composed of pseudolaterite and quartz; strongly acid (field pH 5.5);

clear, smooth boundary.

 71-115+ cm (Btc3) Mixed, red (2.5YR 5/8) strong brown (7.5YR 5/8) yellowish brown (10YR 7/6) gravelly
clay; moderate medium subangular blocky structures; firm, sticky, plastic; moderate thick clay coating
on ped faces; strongly acid (field pH 5.5).

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