Māori horticulturalists identified at least 30 different types of soil.
Oneone means soil, and ‘one’ is used as a prefix for the names of different soil types. One-parakiwai was silt, one-pū was sand and one-nui was a rich soil made of clay, sand and decayed organic matter. ‘Kere’ was used as a prefix for some types of clay, including keretū, kerematua and kerewhenua.
Tenga kākāriki (parakeet’s crop), a white volcanic sand in the Bay of Plenty, was so named because it resembled the rough inner surface of a parakeet’s crop (a pouch near the throat).
A kaumātua (elder) from Ngāti Kahungunu discussed the relative merits of four types of soil for growing kūmara (sweet potato):
[I]f the soil is one-matua [loam] that kumara field should be gravelled; gravel will improve it. The reason why persons dislike that soil is on account of the heavy work of carrying gravel. If a spot having one-paraumu [dark, friable soil] can be found, that is desirable, the work will be light, gravel will be carried only to put under the leaves, lest they suffer from mud and wet. If there be no one-paraumu, and one-haruru [light, sandy loam] can be found, that will serve well as a cultivation ground. The one-tuatara [stiff brown soil] is never approved of, it necessitates so much labour in pulverising, also another labour is carrying gravel for this soil. 1
The preferred soil for growing kūmara was light, warm and sandy. Where this was not available, Māori horticulturalists added gravel and sand, and less commonly charcoal and shells, to the existing soil, probably to improve drainage. Large amounts of gravel were quarried for this purpose, and the holes left from this are known as borrow pits.
Modified soils are found in both the North and South islands, and are also known as plaggen soils.
Missionary William Colenso noted that compared to kūmara, taro required ‘a very different soil and damp situation ... light and deep yet loamy, or alluvial, often on the banks of streams or lagoons, and sometimes at the foot of high cliffs near the sea.’ 2 In Northland, taro was grown in swamps with drainage networks.
To fertilise soil, weeds and ash were spread on it. Before Europeans settled in New Zealand there were few animals capable of producing manure – but even after stock were introduced, Māori at first did not use manure for agriculture. The laws of tapu (initially made to prevent sickness) prevented excrement being associated with food. In some cases, this opposition to manure lasted generations.
In 1929 anthropologist Peter Buck (Te Rangi Hīroa) visited Ra’iatea in the Society Islands, a possible location of Hawaiki, the ancient homeland of Māori. ‘On landing I felt that I should reverently pick up some of the sacred soil of Havai‘i from the first footprint that I made on stepping ashore. But it could not be done, for we landed on a modern wharf with wooden buildings forming the background. ... It was all wrong.’ 3
Red ochre, found in clay, was smeared on people’s faces and bodies as a sign of chiefly status. It was also used on carved items such as waka (canoes) or houses, and even on the bones of the dead. Kōkōwai, one type of red ochre, was rolled into balls, baked in fire or hot ashes, then mixed with shark oil. Tākou was another type of red ochre.
Taioma, a white paint, was created by burning and pulverising a clay of the same name, then mixing it with oil. Pukepoto was a cobalt blue colour found in clay rock. Uku, a white or bluish soapy clay, was used for washing. Food was sometimes cooked by enveloping it in clay mixed with water and placing it in a hot fire.
Place names were often an indication of the type of soil found there, including:
- Kenepuru (sandy silt)
- Kereone (sandy earth), near Morrinsville
- Onetea (light sandy soil), near Dargaville.
- Some places were named after the various clay deposits used for colour, including:
- Kōkōwai Gorge, in Taranaki
- Taioma, in Otago
- Pukepoto, near Kaitāia
- Ōtākou (Otago).