Farming is a way of life in New Zealand. Farms cover about half of the country’s land and are important to our economy. Agriculture has shaped who we are as a nation, but it has also had a big impact on the country’s natural landscape and environment.

From bush, swamp and tussock to farmland

Initially, New Zealand was mainly a bush-clad country that included some swamps, wetlands and tussocklands. Māori burned and cleared bush to make hunting easier and to make way for kūmara plots and other crops. The Europeans followed, and eventually the bush was replaced by farms such as dairy, beef, deer, sheep and crops, orchards and vineyards.

In 1840, bush covered about half of the land area. By 1930, about half of that bush area and a large part of the tussocklands had been turned into pasture. By the Second World War (1939), about 85% of the wetlands had been drained. Land was cleared through:

  • burning and clearing bush
  • draining swamps and wetlands
  • burning tussock grasses in the high country.

Introducing new plant and animal species

Almost all of the country’s agricultural crops and livestock were introduced from outside New Zealand. Māori settlers introduced kūmara, taro, yams and gourds. European settlers brought fruits, vegetables, grains and livestock such as sheep and cattle. Although farmers tried to adapt their practices to local conditions, it wasn’t always feasible. For example, when native vegetation made it difficult to sustain increased stock numbers, English ryegrass, clover and cocksfoot were introduced. Some of the introduced plants and animals, free from the constraints of their native environments, became weeds or pests.

Changes brought about by land clearance and introduced species radically altered ecosystems throughout the country.

Technological advances and agricultural expansion

Technological advances had a big impact on New Zealand farming practices. Road and rail construction made it easier to get products to market, making it financially viable to farm remote areas. Electricity and machinery made it easier to manage increased crop or animal numbers. Refrigeration opened up export markets.

Geologically, New Zealand is a young country. Our soils were never nutrient-rich, especially those formed under bush. As the land was more heavily used for farming, soil nutrients were depleted, and declines in productivity became apparent. Fertilisers, especially superphosphate, came into widespread use to improve soil fertility. With the advent of topdressing in 1949, fertilisers were available to all farmlands, including the high country.

These advances combined with improvements in breeding and animal health and rising commodity and land prices have all played a part in the intensification of farming. We now have the means to grow more milk, wool, meat or produce from the same area of land. Average dairy herd sizes grew from about 100 in 1970 to 400 in 2012.

Environmental impacts and farming

Concerns about farming and the environment are not new. A Parliamentary commission of enquiry in 1920 investigated environmental damage to the South Island’s high country. More recently, in 2004, the Parliamentary Commissioner for the Environment linked a number of issues to intensified farming, such as:

  • loss of biodiversity due to land clearance
  • soil compaction due to high stock numbers
  • reduced soil fertility
  • soil erosion due to land clearance and grazing
  • contaminated soils due to pesticides or overuse of fertilisers
  • water pollution from run-off or animal wastes, leading to eutrophication
  • depleted water supplies due to irrigation demands
  • wetland losses that reduce habitat and contribute to flooding
  • greenhouse gases – farming is responsible for more than half of New Zealand’s greenhouse gas emissions (the global average is 14%).

Find out more on farming and environmental pollution in this article.

Resource Management Act 1991 and other regulations

The Resource Management Act 1991 (RMA) was enacted to promote sustainable environmental management of land through the careful use of resources. The resource consent process has affected how farmers operate their farms. They now need to seek permission to use water for irrigation and to discharge waste into streams and rivers. The RMA passed on most resource management responsibility to local regional councils, such as soil conservation, water quality, flood control and pest management. For example, the Waikato Regional Council has introduced a strategy requiring farmers to limit nitrogen outputs in an effort to protect water quality in Lake Taupō.

Nature of Science

One of the nature of science propositions put forward by Rutherford and Algren (1990) states that scientists participate in public affairs both as specialists and as citizens. When responding to environmental problems linked to human activity, the scientist must base the response on empirical evidence as opposed to the citizen, whose response may be just opinion.

Useful links

Read the Resource Management Act 1991.
www.legislation.govt.nz/act/public/1991/0069/latest/DLM230265.html

An explanation of and guide to the Resource Management Act.
www.mfe.govt.nz/publications/rma/rma-guide-aug06/html/page2.html

    Published 30 July 2013