Podzol
DESCRIBE
EXPLAIN
DRAWN DIAGRAM
B
C
A
AO
Some darker staining in the upper A horizon from humus in AO.
Ash-grey lower A horizon.
Sandy texture.
Fe (iron) and AI (aluminium) minerals deposited.
Well defined horizons.
Few soil biota to mix soil.
Iron pan develops in upper B horizon impeding drainage.
Waterlogging results.
Reddish brown colour.
Denser texture.
Parent material generally made of weathered rock.
Rock is glacial or fluvial-glacial in nature.
Associated vegetation is coniferous forest or heather moorland.
Thin black humus layer.
Acidic Mor humus pH 3.5-4.
Plants have shallow spreading roots.
A
B
AO
- Coniferous needles and cones produce acidic mor humus.
- Low temperatures lead to slow decomposition.
- Shallow roots mean limited absorption of deep leahced minerals.
- Shallow roots also mean limited nutrient recycling.
- Limited soil biota leads to clearly defined soil horizons.
- Eluviation leaves an ash grey A horizon.
- Illuviation leads to a reddish-brown B horizon.
- High precipitation leads to leaching.
- This is the downward movement of AI and Fe oxides.
- This forms an iron pan between the A/B horizons.
- The iron pan may impede drainage and cause waterlogging. - Often found on steep slopes which further encourages leaching.