Page 126 - E-BOOK English

Soil classification

WRB: Haplic Plinthosols
Soil taxonomy: Fine-loamy, mixed, semiactive, isohyperthermic Typic (Aquic) Plinthudults

Soil series: Na Tham series (Ntm)

Profile description

 0-8/11 cm (A) Dark brown (10YR 3-4/3) fine
sandy loam; moderate medium and coarse
subangular blocky structures; firm, nonsticky,
nonplastic; few fine tubular pores; many fine
roots; strongly acid (field pH 5.5); clear, wavy
boundary.

 8/11-25 cm (BA) Yellowish brown (10YR 5/8)
fine sandy loam; moderate fine and medium
subangular blocky structures; firm, nonsticky,
nonplastic; patchy organic matter coating on
ped faces; few very fine tubular pores; common
fine and few medium roots; very strongly acid
(field pH 5.0); clear, smooth boundary.

 25-52 cm (Bt1) Mixed strong brown (7.5YR 5/8)
and brownish yellow (10YR 6/6) sandy clay loam;
common fine and medium distinct yellowish
red (5YR 4/6) mottles; moderate medium
subangular blocky structures; firm, sticky, plas-
tic; patchy thin clay coating on ped faces;
common fine tubular pores; few fine roots; very
strongly acid (field pH 5.0); gradual, smooth
boundary.

 52-74 cm (Bt2) Mixed strong brown (7.5YR 5/8) and brownish yellow (10YR 6/6) clay loam; many
medium distinct yellowish red (5YR 4/6) mottles; moderate medium subangular blocky structures;
firm, sticky, plastic; broken thick clay coating along roots channels, common moderate thick cutan
on ped faces and few thick organic matter coating; common fine and few fine tubular pores; very
strongly acid (field pH 5.0); clear, smooth boundary.

 74-120 cm (Bcgv) Mixed yellowish brown (10YR 5/6) light gray (10YR 7/2) red (10R 4/8) and yellowish red
(5YR 5/8) very gravelly clay; gravels composed of iron stones diameter up to 1.0 cm, rounded sandstone’s
which iron coating diameter about 3-4 cm; very strongly acid (field pH 5.0).

 120-150 cm (BCgv1) Mixed light gray (10YR 7/2) dark yellowish brown (10YR 4/6) and yellowish brown
(10YR 5/8) clay loam; plinthite more than 50% of the matrix; very strongly acid (field pH 5.0).

 150-220 cm (BCgv2) Mixed light gray (10YR 7/2) weak red (10R 4/4) and dark red (10R 3/6) clay;
moderately thick clay coating on ped faces and few thick organic matter coating; plinthite more than
50% of the soil matrix; very strongly acid (field pH 5.0).
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