Podzol Soils [Z]
The impressive contrast in horizons displays the potent effect that particular tree species, for example Kauri, can have on soil formation.
Podzol soils are strongly acid soils that usually have a bleached horizon immediately beneath the topsoil. This horizon is the source of aluminium and iron oxides that have accumulated, in association with organic matter, in an underlying dark or reddish coloured horizon.
Podzol Soils occur in areas of high rainfall and are usually associated with forest trees with an acid litter. The soils occur mainly in materials from silica-rich rocks. They cover 13% of New Zealand.
Podzol soils have low natural fertility, low base saturation, and are strongly acid. Secondary oxides and other clay minerals are strongly differentiated with depth.
Podzols have low biological activity. The vegetation comprises plants that deposit a mor-forming acid litter.
Soil orders are divided into soil groups based on variation in factors such as drainage status, parent material, chemical and physical properties