Omarunui

4 - Omarunui

Soil Properties

Parent material	Water deposit (alluvium) from greywacke and/or sandstone
Characteristic site and soil features	Low terrace adjacent to recent channels; protected from flooding by stop banks: sandy loams overlying permeable older deposits, often stones but maybe heavier textures. If the sandy loams bury impermeable old topsoils, to be included in this mapping unit, they must be deep enough (probably at least 75cm) so that the perched gley is >60cm from the surface.
Associated soils not shown within map unit at map scale but separated out in more detailed maps. - Sample Location	1, 3,   H, O
Natural drainage and depth to gley and hence to water table after wet periods	Good >60cm
Potential rooting depth, texture, and limiting layer	4,  >45cm sandy loam on permeable sediments (maybe stones or heavier textures): >75cm  sandy loam if on slowly permeable old buried  topsoil 4g,  30-45cm sandy loam/loamy fine on stones 4s,  30-45cm sandy loam/loamy fine sand on sand
Available water capacity (AWC)	4,  50-750mm 4g,  30-50mm 4s,  30-50mm
Infiltration rate	Moderate
Permeability rate	Moderate, but slow if old buried topsoil
Susceptibility to pugging and compaction when wet	4  moderate
Susceptibility to wind erosion when dry	4g, high where sand topsoil
Unfavourable soil characteristics	4g,  <45cm to stones    low AWC    rapid permeability  4s,  <45cm to sand    low AWC

 

Soil Management

Artificial drainage	4, 4g, 4s   none required
Cultivate when moist to avoid: compaction wind erosion	4, 4g
Irrigation:- Recommended method Dripper spacing for continuous wetted strip Amount and frequency	4g, 4s,  sprinkler to prevent water loss 4, 4g, 4s  40cm if 4 l/hr drippers used 4g, 4s  little (15-25mm), often to prevent water loss

 
Omarunui sandy loam (4, 4g, 4s) (photo E. Griffiths)