A recent OECD report describes New Zealand’s water quality as ‘good’ relative to most OECD countries but says that it is deteriorating. This deterioration is due, in large part, to diffuse pollution from agriculture, says Dr Kevin Parris of the Trade and Agriculture Directorate, OECD in Paris, France. Dr Parris is a plenary speaker at the DIPCON conference, in Rotorua.
New Zealand’s agriculture is vital to its economy. As New Zealand’s agriculture sector expands, more pressure is put on its environmental systems. Agriculture contributes to water pollution through excess nutrients, pesticides and other pollutants.
Public opinion surveys across OECD countries in recent years have consistently ranked water pollution as one of the top public environmental concerns.
Agricultural nutrients are a major pressure on river , lake and marine water quality, and this is assessed by OECD through nutrient balances, says Dr Parris. “We look at all the nitrogen and phosphorus going into the system, mainly from livestock manure and fertilisers and calculate how much nutrients are used to grow crops and pasture. In most situations there is a surplus of nutrients to crop and pasture requirements which places stress on the environment (soils, water and the air). In 2000, the average for New Zealand was around 35 kilograms of nitrogen per hectare. By 2008 it was about 45 kilograms per hectare. In ten years it has gone up 10 kilograms.”
In 2000, the average for the 34 OECD countries was 80 kilograms per hectare. In 2008 the average for OECD countries had come down to 65 kilograms per hectare. Interestingly, among the worst ranked was the Netherlands with a surplus of over 200 kilos per hectare. “They have a lot of cows and not much land,” says Dr Parris.
Agriculture is a major user of water, and worldwide we face the enormous challenge of producing almost 50% more food by 2030, and doubling production by 2050. This will place still further stress on water quality in New Zealand and worldwide.
There is a “time-bomb” effect from this agricultural expansion. Nitrogen and phosphorus can sit in soil for a long time before they appear in water. “Because of these time lags, in some catchments, we won’t necessarily see the effects of current farming practices for another 30-40 years,” says Dr Parris.
In exploring new policy opportunities and market approaches to minimise diffuse source pollution from agriculture across OECD countries in a report to be published in early 2012, Dr Parris examines the policy, challenges, reforms, opportunities and policy governance issues that face the sector. His findings across OECD countries reveal that policies have generally fallen short of what is required to meet water quality goals in agriculture, including in New Zealand. This is mainly a result of:
• inefficiency and failure in enforcing water pollution regulations,
• increasing budgetary costs of support to farmers to control pollution,
• frustration with the time required and institutional barriers to introduce new policies,
• lack of understanding of the scale and time delays of diffuse pollution,
• and insufficient attention to the establishment of a more inclusive stakeholder process.
Among the key policy messages from the OECD report, Dr Parris recommends using a mix of policy ideas to address water pollution, including enforcing compliance with existing water quality regulations and encouraging cooperative approaches in water catchments that are inclusive to all the major stakeholders concerned with water pollution (e.g. farmers, environmental groups, local government).
Dr Parris will speak on ‘Opportunities for lowering diffuse source water pollution from agriculture’, this Friday in Rotorua at the Dipcon conference.