Podzols

Podzol
Podsol, Podosol, Spodosol, Espodossolo
The picture is of a stagnopodzol in upland Wales, and shows the typical sequence of organic topsoil with leached grey-white subsoil with iron-rich horizon below. The example has two weak ironpans.
Used in	WRB, USDA soil taxonomy, others
WRB code	PZ
Profile	O(Ah)EBhsC
Key process	podzolization
Parent material	quartz rich debris and sediments
Climate	humid continental, subarctic, oceanic, equatorial
H: common O: always, has humified organic matter mixed with minerals A: absent in most boreal podzols E: common, is ashen grey and leached in Fe and Al B: always, receives Fe and Al through illuviation C: common

In soil science, podzols (known as spodosols in China and the United States of America and podosols in Australia) are the typical soils of coniferous, or boreal forests. They are also the typical soils of eucalypt forests and heathlands in southern Australia, while in Western Europe podzols develop on heathland, which is often a construct of human interference through grazing and burning. Many podzols in this region may have developed over the past 3000 years in response to vegetation and climatic changes. In some British moorlands with podzolic soils there are brown earths preserved under Bronze Age barrows (Dimbleby, 1962).

Podzol means "under-ash", and is derived from the Russian под (pod) + зола́ (zola); the full form is "подзо́листая по́чва" (podzolistaya pochva, "under-ashed soil"). The tem introduces in 1875 by Vasily Dokuchaev. It refers to the common experience of Russian peasants of plowing up an apparent under-layer of ash (leached or E horizon) during first plowing of a virgin soil of this type.

Podzols are able to occur on almost any parent material but generally derive from either quartz-rich sands and sandstones or sedimentary debris from magmatic rocks, provided there is high precipitation. Most podzols are poor soils for agriculture due to the sandy portion, resulting in a low level of moisture and nutrients. Some are sandy and excessively drained. Others have shallow rooting zones and poor drainage due to subsoil cementation. A low pH further compounds issues, along with phosphate deficiencies and aluminium toxicity. The best agricultural use of podzols is for grazing, although well-drained loamy types can be very productive for crops if lime and fertilizer are used.