Page 26 - World Reference Base for Soil Resources of Thailand
P. 26
Land Development Department Library
Profile features
Except for areas where poor drainage occurs, Acrisols have
an ochric horizon. This horizon may be underlain by an albic horizon
with yellowish colours. The argic horizon is usually reddish with a
maximum clay content reached in the upper part below, in which
the amount gradually decreases. In many cases, a strongly mottled
of plinthic horizon occurs in the deeper subsoils.
Environment and landforms
Acrisols are developed in tropical, subtropical, and warm temperate regions on old
landscapes with undulating topography. They frequently occur in associations with Petric
Plinthosols and Ferralsols upslope, and with Greysols downslope.
Use and management
Acrisols are acid and nutrient-poor soil. Most areas are used for subsistence agriculture.
Lacking amendments with lime and fertilizer, these soils are rapidly being degraded. Without
sufficiently long fallow intervals of liming and fertilizer, crops have problems with aluminum
toxicity and phosphorus deficiency because of fixation. They are also extremely risky to erosion
when the surface has no cover crops.
22
