Soil colloids Flashcards
1
Q
How big are soil colloids?
A
typically under 1 μm (micrometer)
2
Q
Describe surface charges of soil colloids
A
both internal and external carry negative and/or positive charges
3
Q
What cations dominate in humid regions?
A
Ca, Al, H
4
Q
What cations dominate in arid regions?
A
Ca, Mg, K, Na
5
Q
What is Cation Exchange Capacity (CEC)?
A
a process where cations are exchanged between the surfaces of soil colloids and the soil solution or surface of plant roots.
6
Q
Types of soil colloids
A
1) Inorganic
a) silicate clays
b) iron & aluminum oxide clays
c) allophanes
2) Organic
a) humus
