Reference soil New Zealand 05: Andosol

NZ005

Andosols occur throughout the world where volcanic activity is common, especially in the circum-Pacific region and along the mid-Atlantic Ridge.

Characteristics

Soils with a vitric or andic horizon (slightly to moderately weathered horizons in pyroclastic deposits dominated by short-range-order minerals, notably allophane and imogolite) starting within 25 cm from the soil surface. In addition, they may have a histic, fulvic, melanic, mollic, umbric, ochric, duric, or cambic horizon. Other diagnostic horizons (unless buried deeper than 50 cm by volcanic deposits) are absent.

Distribution of Andosols (rough estimation supplied by soilgrids)

Reference soil NZ005: Andosols

LAND USE: dairying, semi-extensive sheep farming and exotic forestry

Classification

WRB 1998

Epidystri-Vitric- Andosol (Endoeutric)

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Dystri-Vitric Andosol

Vitric Andosol

Local classification:	Moderately leached yellow-brown pumice soil; Taupo sandy silt

Other classification

USDA-NRCS (1999)	Typic Udivitrand
USDA-SCS (1975)	Typic Dystrandept udic medial mixed mesic

Profile description

Ah 0-13 cm	(7.5YR 2/no, moist)sandy loam,weak to moderate coarse nutty subangular blocky and weak to moderate coarse granular,friable weakly smeary,moderately porous (40-60 vol%),many roots,gradual irregular boundary to,
13-18 cm	dark brown (10YR 3/3, moist)sandy loam,weak to moderate medium nutty subangular blocky,friable,moderately porous (40-60 vol%),many roots,frequent worm channels,clear wavy boundary to,
Bw 18-36 cm	yellowish brown (10YR 5/4, moist)sandy loam slightly gravelly,porous massive,firm moderately smeary,moderately porous (40-60 vol%),many roots,few fine gravel weathered pumice lapilli fragments,clear wavy boundary to,
C1 36-44 cm	very pale brown (10YR 7/4, moist)sandy loam gravelly,porous massive,firm,moderately porous (40-60 vol%),few roots,common fine gravel weathered pumice lapilli fragments,gradual wavy boundary to,
C2 44-51 cm	pale yellow (2.5Y 7/4, moist)loamy sand gravelly,porous massive,firm,moderately porous (40-60 vol%),no roots,common fine gravel weathered rhyolite fragments,clear wavy boundary to,
C3 51-69 cm	light grey (5Y 7/2, moist)Description sand,porous massive,very firm,moderately porous (40-60 vol%),no roots,abrupt wavy boundary to,
C4 69-87 cm	very pale brown (10YR 7/4, dry) light grey (5Y 7/2, moist)loamy sand gravelly,porous massive,firm moderately smeary,moderately porous (40-60 vol%),no roots,common fine gravel weathered pumice fragments,abrupt wavy boundary to,
C5 87-108 cm	pale yellow (5Y 8/3, moist)gravel,porous massive,loose,highly porous (>60 vol%),no roots,dominant fine and medium gravel weathered pumice fragments,abrupt wavy boundary to,
2C6 108-113 cm	pale olive (5Y 6/3, moist)loamy sand,porous massive,firm,moderately porous (40-60 vol%),no roots,abrupt wavy boundary to,
113-125 cm	reddish yellow (7.5YR 7/6, moist)loamy sand,porous massive,firm moderately smeary,moderately porous (40-60 vol%),no roots,

Kind 1 (parent material) ; Parker (eds), 1984	pumice
Mode of accumulation or deposition of parent material	ejecta ash
Remarks on Parent Materials	Rhyolitic pumice (Taupo pumice) erupted 250 AD
Texture of parent material (second entry)	silty
Weathering Resistance	poor
General characterization of the status of weathering of solid rock	partially or moderately

Land use or vegetation in the immediate vicinity of the site	dairying
Remarks on Land Use / Vegetation	VEGETATION: tussock, cocksfoot, bracken fern, mingi mingi. Original vegetation: Manuka scrub and bracken fern. Area had podocarp forest prior to Polynesian fires.
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	grassland

Altitude	325m
Physiographic position of the site	flat
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	plateau
Slope	0%
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	flat or almost flat

Drainage class ; FAO (2006) - Guidelines for soil description	well
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	0-110cm
Estimated permeability (class) of least permeable part of the profile	high
Estimated run off (class)	rapid

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Evidence of salt; Soil Survey Manual USDA, 1951	non-saline

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Reference soil New Zealand 05: Andosol

Characteristics

Reference soil NZ005: Andosols

Classification