Historical Development of Pastures
In the very early years of settlement when the mission stations opened in the northern part of the North Island, the establishment of grassland was a small part of self-sufficiency farming based mainly on the growing of food for humans. The first sowing of grass was carried out on land cleared from fern near Kerikeri, Northland, on 20 July 1821. When farming commenced later in the South Island, the native tussock grassland provided a large area of ready-made grazing. The native grassland which covered much of the hills and plains lying to the east of the Southern Alps contained many palatable grasses and herbs and was rapidly stocked with sheep, with little effort other than fencing. On much of the easier country the tussock grassland was ploughed to grow crops, and was then sown in pasture. Although some of this pasture was of good quality, much of it was poor, particularly where moisture was a limiting factor, and the grassland had to be renewed in a frequent rotation with cereals. Much of the tussock grassland which was not ploughed became considerably modified as the result of burning and grazing by sheep and, in some areas, by rabbits. As a result of this treatment some of the grassland almost disappeared and was replaced by manuka in the higher-rainfall areas and by the unpalatable scabweed in the areas of low rainfall. In many parts the changes were not great, the main one being the replacement of some of the palatable herbs, which could not survive, by the more tenacious grasses and herbs. After some 100 years of farming, the tussock grasslands have reached a state of near stability – the degree depending on the treatment they have received.
In the North Island the development of grassland was quite different. Except for parts of the tussock grassland of the Central Plateau, the land was covered with forest, fern, and scrub. Grassland farming, therefore, had to be preceded by the destruction of the original vegetation. After this was cut and burnt, grass seed was sown by hand on the ash among the logs and stumps. The results of this policy of burning and sowing were variable. In some of the more fertile areas good pastures were established. In others, however, unpalatable native plants such as fern, piripiri, tauhinu, and manuka became established, spread, and eventually crowded out the sown grasses, so that little or no grazing was available to stock. As a consequence, considerable areas of the North Island hill country wholly or partly reverted to these unpalatable plants. Some of this land was later cleared and sown down a second time, but its low fertility made it very difficult to maintain good grazing pasture. Only during the last few years has the permanent recovery of some of this country been made possible by the raising of fertility due mainly to the use of aerially applied fertilisers. Nevertheless, on much of the higher fertility country there was little reversion, and good clean pastures developed when the logs and stumps had been burnt or had rotted away.