Different soil types
The variety of rock types on the West Coast is reflected in a wide range of soil types. However, the soils used for agriculture in lowland areas can be generalised into three broad groups:
- Recent soils are located on river flats and in some areas are still subject to occasional flooding. Despite being often deficient in lime, these soils have the highest natural fertility, although continued fertiliser application is required for successful agricultural production.
- Yellow-brown earths are found on lower terraces and rolling morainic (rocky) and hill country. These soils have been leached by the heavy rainfall, and are of lower fertility than recent soils. The only exception is the lower Grey Valley, in the rain shadow of the Paparoa Range, where rainfall is lower.
- Gley podsols, which are waterlogged and nutrient-poor, are found on older terraces and moraines (glacial rocks). High rainfall over a long period has led to the formation of an impervious iron pan (layer) that impedes drainage. These unproductive flat areas, widespread around Westport, are locally known as pākihi (from a Māori word that originally meant open country).
The arrival of gold miners led to the development of small farms that provided vegetables, potatoes and dairy products, as well as some hay and chaff for horses. Sheep and cattle were driven over passes from Canterbury to provide meat for the miners.
In the 1880s the West Coast had more than 30% of the domestic goats in New Zealand. Goats were the typical dairy animal of the gold miner – able to scavenge in the bush, and giving a fair return of milk for minimal attention. Thousands of their descendants roam the bush today.
With a high rainfall spread across the year, and a moderate climate, there is a ready supply of grass, and cattle can live outdoors all year. After paddocks were fenced, sheep were introduced, but the climate is generally too damp for successful sheep farming.
Rise of dairy factories
Changing technology in the early 20th century led to the development of the dairy industry. Cows could be milked by machine, and cream could be mechanically separated. On the West Coast this led to the development of a chain of small farmer-owned dairy companies, from Ōkuru in the south to Karamea in the north, producing mainly butter.
Cows versus sheep
Buoyant international prices for dairy products from the mid-1980s led farmers to reduce sheep numbers and move into dairying. By 1999 the West Coast had become the only region where there were more dairy cows than sheep.
As rivers were bridged and roads improved after the Second World War, there was a gradual amalgamation of dairy companies. The Westland Co-operative Dairy Company became dominant, and gradually absorbed other companies – Arahura, Harihari, Greymouth, Reefton, and finally Karamea in 1987. By that time, tankers were calling daily at farms to collect milk rather than cream, and transporting the milk back to a central factory that produced milk powder and a range of other products, as well as butter and cheese. The company has been reconstituted as Westland Milk Products, and is one of the few dairy companies independent of Fonterra, which dominates the industry in the rest of New Zealand.
In 2014 tankers from the Westland Milk Products factory in Hokitika collected 750 million litres of milk from 425 farms spread between Karamea and Franz Josef.
Improving wet soils
An increasing demand for land suitable for dairying has led to the developments of two techniques to improve wet soils, both using modern hydraulic excavators.
- Humping and hollowing involves recontouring the land into a corrugated surface to stop water from pooling.
- Flipping is when the soil is dug to a depth of 2–3 metres, partly inverting and mixing it, and breaking up any iron pan to improve drainage.
Both techniques involve adding fertiliser (often a special ‘pākihi mix’) and reseeding with grass. Overall there has been a substantial rise in agricultural production, and some previously abandoned land has been turned into farmland.