SOME PROPERTIES OF
The crystalline properties are typically characterized by special kind of clay materials, allophane,
imogolite, halloysite and ferrihydrite. Allophane is a round sphere (see figure
below), extremely reactive (up to 800 square m per gram) but lacks the cohesion of typical
clays found in other common soil types, such as smectite.
The soil is light and very porous. It can store large quantities of water, much more than
any other soils except for organic soils (Histosols), often more than 100% on weight basis
when saturated with water.
Andosols have a tendency to bind organic matter and therefore often contain much more
organic materials than other soils under similar conditions.
The soils have a tendency to bind phosphorus so tightly that phosphorus fertilizers are
often needed when growing crops on these soils.
Lack of cohesion
These soils often lack of cohesion and exhibit a property called phixotrophy, which means
they can all of a sudden start to behave like a liquid when they contain high amount of
water. This can cause problems such as landslides and various engineering problems.
Last modified 30 October 2003