Okawa

29, 29G - Okawa - Dominant Soil @ Map Scale 1:50000

Associated Soil/s	30, 32 may also be found within these areas (29, 29g) if a more detailed survey was carried out.
Soil Properties of Dominant Soil/s
Parent material	Mostly alluvium from loess and some volcanic ash but also includes stony alluvium derived from erosion of Castlecliffian deposits
Characteristics of site	Valley floor between ridges of 42 and depressions (watercourses) on plain
Soil features	Silt loam on sandy loam on cemented pan
Natural drainage Depth to perched gley	Poor Water perched at <30 cm on pan
Potential rooting depth, texture, and limiting layer	29 - 30-45 cm silt loam on gleyed sandy loam on cemented pan 29g - 30-35 cm sandy loam on gleyed sandy loam on stones
Available water capacity	29 – 50-75 mm 29g - 25-40 mm
Infiltration rate	Moderate but slow if compacted
Permeability rate	Very slow
Susceptibility to pugging and compaction when wet	Very high
Susceptibility to wind erosion when dry	High
Unfavourable soil characteristics	Poor drainage, water perched on pan Very slow permeability Topsoil easily compacted, causing slow infiltration

 

Soil Management of Dominant Soil/s

Artificial drainage	29 – mole drains above pan
Cultivate when moist to avoid compaction	29, 29g
Irrigation:- Recommended method Dripper spacing for continuous wetted strip Amount and frequency	29, 29g - sprinkler to prevent waterlogging If 4 l/hr drippers used 29 – 60 cm 29g – 40 cm 15-25 mm often to prevent waterlogging

 

Okawa (29,29g) (photo K. Vincent)