A New report by the Parliamentary
Commissioner for the Environment says integrated pest management (IPM)
schemes should be used throughout agriculture, as part of a call for more
environmentally sustainable agricultural practice.
Growing for Good: Intensive Farming, Sustainability
and New Zealand’s Environment says some farmers are using more fertiliser,
energy and water for irrigation, and reviewed the horticulture, viticulture
and dairying sectors in Canterbury, Waikato, Hawke’s Bay and Southland
assess environmental impacts of these sectors. “IPM is one component
of farming that has been fundamentally re-designed,” says commissioner
Dr J. Morgan Williams.
“It takes a systems approach in which decisions
are made in the context of the ecology of the farming system. A Systems
approach is highly relevant in efforts to improve agricultural sustainability
and there are opportunities to apply it much more broadly across farming
sectors in New Zealand.”
DRIVE FOR PRODUCTIVITY
In his report, D Williams says after de-regulation
of the agricultural sector in 1985, New Zealand farmers were encouraged
to aim for higher levels of productivity. In response, some boosted
“material and energy inputs” in an effort to lift production, while some
focused on “high-value production and quality” through certification schemes.
“If you compare the horticulture industry with
intensive sheep and beef farming, there’s quite a difference.”
Horticulture has been characterised by a focus
on growth in value and associated intellectual property. Growers
have pushed IPM in their whole orchard-to-market approach.
“Integrated fruit production is essentially a
broad-based IPM programme and that is simply saying, ‘what is the most
cost-effective and ecologically sound way to operate?’ The kiwifruit sector,
for example, has been dramatically transformed by the KiwiGreen programme.”
Dr Williams cites other examples, in which produces
have responded to greater concern among consumers about food quality and
safety.
These include AcoGreen for avocados, SummerGreen
for summer fruit, integrated fruit production for pipfruit, which achieved
a 93% decrease in organophosphate pesticide use and a 50% overall decrease
in insecticide use among growers since its inception in 1996; and sustainable
wine growing. “Producer groups have responded to these concerns with
schemes to improve product ‘traceability’, and with assurance programmes
which are most common in the horticultural sector, in which a variety of
IPM programmes have been developed for fruit and vegetables.
“The broad trend in horticulture is toward environmental
management systems that reduce pesticide use.”
Dr Williams says he has a long interest in pest
management approaches, because he did his PhD on the subject. He
says New Zealand has a “positive horticulture story”, particularly when
compared with the United States.
“President Bill Clinton and Vice-President Al
Gore set goals for fruit production to be managed by IPM within a certain
proportion,” he says, “but there was much hand wringing at the slow uptake.
IPM is more complex – it’s much more simple to calendar spray.
“If you look at the past 10-15 years in New Zealand,
there have been more biological techniques to manage pests and our total
pesticide and herbicide use has been decreasing.”
“In the report, we deliberately didn’t focus much
on pesticides, because the big risks to our ecology are more the way we
are tracking with the nutrient side of the story, than pesticide risks.
Pesticides were focused on three-four decades ago.
CONCERNS OVER NITROGEN FERTILISER
Dr Williams says New Zealand farmers are moving
away from natural sources of nitrogen in soil and relying more on synthetic
fertilisers.
He says nitrogen can enter streams as surface
run-off or leach through soil into contaminated groundwater, and can affect
the quality of drinking water supplies. He says once nitrogen leaches
into the environment, there is no effective way to remove it.
The use of urea fertiliser in kiwifruit growing
increased 49% from 1996-2002, with a 3% increase in the pipfruit industry,
the report said.
Diammonium phosphate use in the vegetable growing
sector rose 150% in the same period.
Dr Williams raises grave concerns about the way
nitrogen fertiliser is used and its impact on our waterways. He says
the extent of its use in horticulture varies among crops.
“Gold kiwifruit has a high requirement for nitrogen
fertiliser. It’ a very successful fruit. I love it and I am
an addicted eater, but we are not focusing on the use of nitrogen per se,
it’s the way we use it.”
CATCHMENT APPROACH TO IRRIGATION
New Zealand’s irrigated land area was increasing
55% nationally each decade, with irrigated horticultural and viticultural
land up around 300% in the 17 years to 2002.
Hi report outlined recent strip tillage and no
tillage trials – when compared with conventional cultivation – by Hawke’s
Bay-based Landwise, which aim to reduce soil erosion and resulting nutrient
loss, water loss by evaporation, labour requirements and fuel use.
Landwise director Dan Bloomer, an Irrigation New
Zealand Board member, contributed to a Code of Practice introduced earlier
this year, designed to assess the efficiency of irrigation systems performance
and maximise profits from irrigation.
He says irrigation contributes nearly $1 billion
yearly to the national economy, but accounts for around 77% of water used.
In his report, D Williams says farmers need to
work as a community to manage the effect of nutrients on the health of
waterways.
“Our focus on integrated catchment management
is more in terms of nutrient management and the connection between water
retention and water use. To manage water quality you can’t look at
it individually at a farm level. A series of businesses contribute
to a whole sub-catchment.
“We are trying to stimulate discussion on how
to maintain the long-term, ecological health from the natural capital that’s
creating much of our wealth in New Zealand.
“We are trying to get the business of farming
to focus on being an ecological business system. The horticulture
industry has gone further down the ecological development side than others.”
