Soil Buffer Ranges

Question 0

Iron buffer range: (2)

Answer 0

pH 3.2 - lowest pH value.

Dissolution of iron oxides.

Question 1

Solution is buffered if it’s

Answer 1

pH remains constant, even though small amounts of acid or base are added to the solution.

Question 2

Aluminium buffer range: (4)

Answer 2

pH 3.2 - 4.2 - second lowest pH value.
Aluminium toxicity is a major issue.
Rate of buffering depends on the type of clay.
Dissolution of aluminium from clay minerals.

Question 3

Carbonate buffer range: (2)

Answer 3

pH 6 - 8 - highest pH value.

High neutralisation capacity of calcium carbonate.

Question 4

Silicate buffer range: (2)

Answer 4

pH 5 - 6 - second highest pH value.

Soils dominated by silicate rocks.

Question 5

Exchangeable cation buffer range: (3)

Answer 5

Occurs over whole pH range.
Occurs in forests in Europe.
Removal of basic cations and exchange for hydrogen ions in solution.