Soil Order

Pallic Soils [P]

A cubic metre of some subsoils can weigh more than 1.8 tonnes.

Pallic Soils have pale coloured subsoils, due to low contents of iron oxides. The soils have weak structure and high density in subsurface horizons. Pallic Soils are dry in summer and wet in winter

Gammations in a Pallic soil, Balclutha.
Gammations in a Pallic soil, Balclutha.
Mottled Fragic Pallic.
Mottled Fragic Pallic.
Pallic Soil, North Canterbury.
Pallic Soil, North Canterbury.

Occurrence

Pallic Soils occur predominantly in the seasonally dry eastern part of the North and South Islands, and in the Manawatu. Parent materials are commonly loess derived from schist or greywacke. They cover 12% of New Zealand.

View map View map of Pallic soils.

Physical properties

Soils have slow permeability with limited rooting depth, and medium to high bulk density. They are susceptible to erosion because of high potential for slaking and dispersion.

Chemical properties

Soils have medium to high nutrient content ( except for sulphur), high base saturation, low concentrations of secondary oxides, and low organic matter contents.

Biological properties

Soils are strongly worm-mixed, at the boundary of the A and B horizons.

Soil groups

Soil orders are divided into soil groups based on variation in factors such as drainage status, parent material, chemical and physical properties

[PP] Perch-Gley Pallic

Periodic wetness caused by a perched water table

[PU] Duric Pallic

Silica-cemented pan in the subsoil

[PX] Fragic Pallic

A compact pan in the subsoil

[PL] Laminar Pallic

Clay accumulation as thin subsoil bands subsoil

[PJ] Argillic Pallic

Clay accumulation as thin coatings on peds or in pores

[PI] Immature Pallic

Weakly expressed Pallic soil features