Control del tráfico

As illustrated in Figure Two, a range of national factors influenced the development of water quality interventions in New Zealand. The first section investigates how changes in New Zealand economic policy encouraged diversification, which resulted in the expansion and intensification of New Zealand’s dairy industry. As will be presented later in the chapter, expansion and intensification of the dairy industry contributed to a decline in freshwater quality and encouraged the introduction of water quality interventions.

Expansion and intensification of dairy farming

A significant and dramatic change in New Zealand’s economic policy during the 1980s, was identified by MacLeod and Moller (2006) as one of the main drivers for a change in pastoral land use. Following the National government’s defeat in a snap election in 1984, the incoming Labour government aimed to reduce government intervention in the economy and adopted a policy of economic deregulation. All agricultural production subsidies were removed in the government budget, including subsidies for fertiliser, the eradication of noxious weeds and Supplementary Minimum Prices (SMPs)19 _{(W. Smith & Montgomery, 2004). The policy changes and impacts on} the agricultural industry are well documented (e.g. Fairweather, 1992; Rhodes et al., 2003; W. Smith & Montgomery, 2004). SMPs and subsidies had artificially increased the profitability of sheep and beef farming compared with dairying (W. Smith & Montgomery, 2004), and the removal of subsidies economically affected sheep and beef farmers more than dairy. The removal of subsidies encouraged diversification: sheep and beef to dairying, farmland to forestry, and increased areas in viticulture and horticulture (W. Smith & Montgomery, 2004).

Expansion of the dairy industry has occurred through three key mechanisms since the 1970s: increased farm size, increased per cow production, and an increase in input use (intensification) (LIC, 2016). In terms of increasing farm size (farm area and cow number), industry statistics illustrate a gradual increase in the total number of cows over the 1970s and 1980s, and a more rapid increase from the late 1980s/early 1990s to the latest recorded data for the 2015/16 season (Figure Three) (LIC, 2016). These statistics indicate that the national dairy herd increased from 2.08 million cows in the 1974/75 season (LIC, 1999), to 2.44 million cows in the 1991/92 season, to 5.00 million cows in the 2015/2016 season (LIC, 2016). Combined with increase in total cow numbers, dairy farms increased in size (total effective area - ha), but the number of herds declined, and the average herd size increased - herd size has more than tripled from the 1974/75 to the 2015/16 season (LIC, 2016).

Figure 3: Trend in the total number of dairy cows in New Zealand from the 1974/75 to 2015/16 seasons. Source: (LIC, 2016)

Although dairy farming has been historically based in the North Island for climatic reasons (rainfall), the regional dairying pattern has changed over time. Figure Four illustrates that at the end of the 1990s (1998/99 season), the majority of dairy farms were located in the North Island (86%; South Island 14%) (LIC, 1999). The most recent statistics for the 2015/16 season, however, illustrate that while the majority of dairy herds are still located in the North Island (59.7%), dairying has noticeably increased in the South Island (40.3%) (LIC, 2016) with a movement into ‘non- traditional dairy farming areas’ (e.g. Canterbury and the dry semi-alpine McKenzie country) (Fraser, Ridler, & Anderson, 2014). Irrigation removed climatic restrictions (rainfall) on dairy farming in the South Island, and Moot, Mills, and Pollock (2010) describe how the increased

availability and the rapid expansion of irrigation in Canterbury contributed to the conversion of sheep and beef farms to large scale dairy production. Herds are on average larger in the South than the North Island, in terms of the number of cows and the average herd size (average herd size for the 2015/16 season: South Island 624, North Island 343) (LIC, 2016).

Figure 4: The regional distribution of dairy cows in New Zealand for the 1998/99 and 2015/16 seasons. Source: (LIC, 1999, 2016).

Over the last two decades, an increasing trend towards more intensive dairy farm systems has been noted (Foote, Joy, & Death, 2015). Following Moller et al. (2008), intensification of agricultural practices in a New Zealand context is defined as ‘any increase in farm inputs or farm production off-takes per unit area of land’ (p.254). Intensification has largely occurred through a gradual shift from traditional low input pastoral based systems, to higher off-farm input based systems (MacLeod & Moller, 2006; Parliamentary Commissioner for the Environment, 2004). Off- farm inputs include bought-in supplementary feed (e.g. maize and grass silage, palm kernel extract (PKE) and grain), non-nitrogenous and nitrogenous fertiliser and irrigation (in some areas) (Fraser et al., 2014; MacLeod & Moller, 2006; Parliamentary Commissioner for the Environment, 2004). Irrigation enabled farmers to intensify production in drought prone areas, or regions with seasonally low or unpredictable rainfall (MacLeod & Moller, 2006). Dairy farm systems intensified in order to increase output, lift revenue (farm and national scale), and to maintain international competitiveness. Intensification has resulted in an increased stocking rate (average cows/ha), increased per cow milk production (kg MS/cow), and increased production per hectare (kg MS/ha) since the 1970s (LIC, 2016). Intensification has also resulted in an increase of nutrients entering the farm system through increased cow numbers, nitrogen fertiliser and supplementary feeds, and as a result, an increased quantity of nutrients that can runoff or be leached from the farm

increased pathogens (e.g. E.coli from cattle faeces), and a potential for increased soil impacts (e.g. soil disturbance and erosion) which contribute to sedimentation of waterways.

More intensive dairy farm systems can impact on the environment. The consequences of more intensive dairy farm systems can include: reduced biodiversity, degraded recreational areas, increased soil compaction, increased water abstraction, increased greenhouse gas emissions and reduced freshwater quality (Foote et al., 2015; Fraser et al., 2014). Additionally, intensive dairying can harm New Zealand’s ‘clean and green’ image, argues Foote et al. (2015). Others are concerned about increased dairying in ‘non-traditional’ dairying regions (Fraser et al., 2014), and the potential impact on the ecological and aesthetic values of these landscapes. The debate between environmentalists and landowners over the large-scale development of some of the South Island’s iconic high country regions (e.g. the McKenzie Basin) for agricultural purposes20 _{has been widely} reported in the media (Benny, 2014). The next two sections discuss the question: how is dairy farming affecting freshwater quality in New Zealand?

Is dairy farming affecting freshwater quality in New