Irongate

20-21 - Irongate

Soil Properties

Parent material	Water deposit (alluvium) of Ngaruroro from greywacke and/or sandstone
Characteristic site and soil features	Young flood channels of Ngaruroro in historical times when the river flooded to the north of Roy's hill; mostly shallow (21) sandy/silt deposits over stones adjacent to the Irongate stream but deeper (20) in channels cut in the pumice (7, 8)
Associated soils not shown within map unit at map scale but separated out in more detailed maps. - Sample Location	2, 56 O
Natural drainage and depth to gley and hence to water table after wet periods	Poor <30cm
Potential rooting depth, texture, and limiting layer	20 >45cm light silt loam on sand to stones at >100cm 20s 30-45cm light silt loam on sand to stones at >100cm 21 30-60cm sand/sandy loam on stones
Available water capacity (AWC)	20 50-75mm 20s 30-50mm 21 30-75mm
Infiltration rate	20, 20S moderate 21 rapid if sand topsoil
Permeability rate	20 rapid to moderate 20s rapid 21 very rapid
Susceptibility of topsoil to pugging and compaction when wet	20 high 20s high 21 low to moderate
Susceptibility to wind erosion when dry	21 high if sand topsoil
Unfavourable soil characteristics	20 if silt loam 45cm - rapid permeability 20s low AWC rapid permeability 21 <45cm - low AWC rapid infiltration if sand topsoil very rapid permeability

Soil Management

Artificial drainage: drain spacing low position subject to flooding drainage difficult because of low position
20,20s   40-60m
21           60-80m

Cultivate when moist to avoid:

compaction
wind erosion
20, 20s
21          if sand topsoil

Irrigation:-

Recommended method
Dripper spacing for continuous wetted strip
Amount and frequency 20s,21    sprinkler to prevent water loss if 4 l/hr
                 drippers used
\20, 20s 50cm
21           30-40cm
20s, 21 little (15-25mm), often to prevent water loss

Irongate (20,21) (photo K. Vincent)