Agriculture in New Zealand - Environmental Impacts

Environmental Impacts

See also: Environmental issues with agriculture and Water pollution in New Zealand

Both the original Māori people and the European colonists made huge changes to New Zealand over a relatively short time. Māori burned forest to flush out game and to encourage the growth of bracken fern, which was used as a food source, and practised agriculture using plants they brought from tropical Polynesia. The Europeans logged and burned off a third of the forest cover to convert land to pastoral farming.

In 1993, the National Institute of Water and Atmospheric Research summarised available data on the quality of water in rivers. They concluded that "lowland river reaches in agriculturally developed catchments are in poor condition" reflecting "agriculturally derived diffuse and point source waste inputs in isolation or in addition to urban or industrial waste inputs". The key contaminants identified in lowland rivers were dissolved inorganic nitrogen, dissolved reactive phosphorus and faecal contamination. Small streams in dairy farming areas were identified as being in very poor condition. New Zealand's rivers and lakes are becoming increasingly nutrient enriched and degraded by nitrogen, animal faecal matter, and eroded sediment. Many waterways are now unsafe for swimming. Fish and Game New Zealand launched a "dirty dairying" campaign to highlight the effect of intensive agriculture on waterways. Fonterra, the largest dairy company in New Zealand, in conjunction with government agencies responded with the Dairying and Clean Streams Accord. In 2009, the Crafar Farms group of dairy farms in the North Island became known as the 'poster boys for dirty dairying' after a string of prosecutions in the Environment Court for unlawful discharges of dairy effluent.

In 2004 the Parliamentary Commissioner for the Environment released a report on the environmental effects of farming in New Zealand. It noted that the trend was towards an increasing pressure on New Zealand's natural capital. Between 1994 and 2002 the number of dairy cows increased by 34% and the land area used grew by just 12% resulting in a more intensive land use. In the same period synthetic fertiliser use across all sectors grew by 21% and urea use grew by 160%.

Almost half of the greenhouse gas emissions in New Zealand are due to the agricultural sector. A portion of this is due to methane from belching ruminants. An agricultural emissions research levy was proposed, quickly becoming known as the "Fart Tax". The proposed levy encountered opposition from the farming sector and the National Party, resulting in plans for the levy being abandoned. The Pastoral Greenhouse Gas Research Consortium was formed as an alternative to imposing the levy on farmers.