Kōrero: Soil investigation

Whārangi 4. Golden age of soil survey: 1951–1985

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Major surveys

After the Second World War, surveys were made as a result of requests from local authorities, agricultural groups, and the need to understand soils in places where there was little information. There were major investigations in:

  • Gisborne plains – later used to plan intensive horticulture
  • Rotorua–Taupō region – for planning farms and forestry
  • Fruit-growing areas of Central Otago
  • Manawatū sand country.

There was often a gap of a decade or more between a survey and the publication of maps and a descriptive monograph. This delay prevented the rapid acceptance and use of new information.

The first manual

Soil survey method by Norman Taylor and Ivan Pohlen was published in 1962. A distillation of 30 years’ knowledge, it was the first comprehensive New Zealand soil survey manual. It set standards for soil description and mapping, and included the first published version of the New Zealand genetic soil classification.

In 1962 the DSIR Soil Bureau moved to Taitā, in the Hutt Valley. It was a productive research centre, although its isolation and lack of contact with agricultural groups ultimately led to its closure 30 years later.

Competing surveys

By the late 1960s the demand for soil surveys outstripped the resources available, and there was overlap and competition between organisations. The Lands and Survey Department started its own series of 1:63,360 (1 inch to the mile) soil maps of counties based on Soil Bureau mapping. The National Soils and Water Conservation Authority undertook a national land resource survey, also at 1:63,360 scale, with soil information.

A 1980 DSIR discussion paper, Land alone endures, addressed the role of research in effective land use, and the problem of sharing information between government agencies. Widely distributed, it helped to draw attention to the loss of highly productive soils near urban areas, as well as the lack of research behind decisions about land use.

The role of universities

Canterbury Agricultural College (later Lincoln College, then Lincoln University) was the first university organisation to teach soil science, starting with Leonard Wild in 1915. More emphasis was given to soil survey after Tom Walker became foundation professor of soil science in 1952.

Massey Agricultural College (later Massey University) started teaching soil science in 1937, and Abe Hudson was made the first professor of soils and field husbandry in 1951. Long-term field trials led to the setting up of the Fertiliser and Lime Research Unit. Soil science papers have also been taught at Waikato and Victoria universities since the 1960s.

Stopping erosion

In the 1970s there was a plan to clear-fell beech forest on the West Coast and plant pine trees. Research by the Forest Research Institute and Soil Bureau showed that some areas would erode once the forest was gone. The picture of bare, worn-away hills convinced many that the scheme should not go ahead.

A team approach

One strategy for quicker soil surveys was to use large numbers of staff for concentrated fieldwork. For example, Soil Bureau teams, sometimes using helicopters, surveyed large areas on the West Coast for potential farming and forestry. Similar team surveys were made on Stewart Island, and in the upper Waitaki valley, King Country and Manukau City.

Backhoes and portable drilling rigs began to replace traditional excavation with spade and auger drill.

Me pēnei te tohu i te whārangi:

P. J. Tonkin, 'Soil investigation - Golden age of soil survey: 1951–1985', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/mi/soil-investigation/page-4 (accessed 16 December 2019)

He kōrero nā P. J. Tonkin, i tāngia i te 24 Sep 2007