With most of the region being mountainous or hilly and forested, soils are generally leached podsolised yellow brown earths or gley podsols which are shallow in depth and low in fertility. The combination of steep slopes, high rainfall and seismic activity commonly result in high erosion rates.
At high altitudes the crests of the ranges are frequently bare.
In the valley floors the soils are recent gley or organic soils. On higher terraces these are the poorly drained and badly leached pakihi soils.
On lower lying sites closer to valley floors, the soils are more freely drained and have a higher natural fertility. These soils are more productive and form an essential element in the region’s agricultural economy. Susceptibility to flooding and bank erosion can, however, be a constraint on their use.