New Zealand Soil Classification (NZSC)

Soil orders

If you are unfamiliar with New Zealand soil orders, Hewitt (2013) provides an easy-to-read introduction.

The New Zealand Society of Soil Science has produced a poster depicting all soil orders.

Below, the 15 NZSC soil orders are introduced in more detail.

Allophanic Soils [L]

Allophanic Soils are dominated by allophane (also imogolite or ferrihydrite) minerals.

Anthropic Soils [A]

Anthropic Soils are constructed by, or drastically disturbed, by people.

Brown Soils [B]

Brown Soils have a brown or yellow-brown subsoil below a dark grey-brown topsoil.

Gley Soils [G]

Gley Soils, together with Organic Soils, represent the original extent of New Zealand wetlands.

Granular Soils [N]

Granular Soils are clayey soils formed from material derived by strong weathering of volcanic rocks or ash.

Melanic Soils [E]

Melanic Soils have black or dark grey well structured topsoils.

Organic Soils [O]

Organic Soils are formed in the partly decomposed remains of wetland plants (peat) or forest litter.

Oxidic Soils [X]

Oxidic Soils are clayey soils that have formed as a result of weathering over extensive periods of time in volcanic ash or dark volcanic rock.

Pallic Soils [P]

Pallic Soils have pale coloured subsoils, due to low contents of iron oxides.

Podzol Soils [Z]

Podzol soils are strongly acid soils that usually have a bleached horizon immediately beneath the topsoil.

Pumice Soils [M]

Pumice Soils are sandy or gravelly soils dominated by pumice, or pumice sand with a high content of natural glass.

Raw Soils [W]

Raw Soils are very young soils. They lack distinct topsoil development or are fluid at a shallow depth.

Recent Soils [R]

Recent Soils are weakly developed, showing limited signs of soil-forming processes.

Semiarid Soils [S]

Semiarid Soils are dry for most of the growing season. Rain is not sufficient to leach through the soil, so lime and salts accumulate in the lower subsoil.

Ultic Soils [U]

Ultic Soils are strongly weathered soils that have a well-structured, clay-enriched subsoil horizon.