Various targets have been set in the
Netherlands to promote sustainable agriculture. It is certainly needed. The
Netherlands has the most intensive agriculture in the world, posing a particular
threat to ground water quality. On average 20 kg/ha of active ingredients are
used per year, including soil sterilants, whereas the European norm is nearer 5
kg/ha.
In arable farming and outdoor
horticulture, the government requires pesticide use to be reduced by 50% from
the 1985-88 average by 2000. Practices at Nagele are seen as the best way to
achieve competitive sustainable agriculture. The target is for 30% of Dutch
farmers to adopt its practices by 1994, rising to 100% by 2000. To date, 500
farmers have taken up IFS, and while the 1994 target will not be reached,
reduction targets generally are on course. This is encouraging: “three or four
years ago there was less enthusiasm for IFS in the farming community. In the
last few years this has changed as more farmers have seen that IFS is becoming
feasible” according to Frank Wijnands.
No industry involvement
Nagele is a 72 ha. arable and vegetable research farm.
Until 1991 three systems, conventional (agrochemical), integrated and organic,
were studied. However the conventional trials have been dropped because they
were not considered necessary as a control.
This is a major difference between the
Netherlands, which is not supported by the agrochemical industry, and other
European countries—particularly Germany and the UK. “We see no need
for the agrochemical industry to become involved in IFS” says Frank Wijnands,
whose project is funded by the government and the farmers’ union. “I see
pesticides as something to avoid and only use if absolutely necessary, the
agrochemical industry see them as essential, when used properly. This shows a
clear difference in attitude which will inevitably result in a different IFS.”
The IFS system is a holistic, whole-farm, concept, which promotes management and
knowledge in place of chemicals.
Crop rotation
Crop rotation is considered ‘multi-functional’
which means it has important implications for crop protection and nutrient
balance, and helps prevent the build-up of crop-specific pests. At Nagele
potatoes are used in a 1:4 rotation with sugar beet, vegetables and cereals.
This is a compromise between a more environmentally desirable, but less
profitable, rotation of 1:5 or 1:6 and a more stressful 1:3 which would require
more inputs.
Pesticide reduction
Compared with conventional farming, pesticide use in
IFS has been reduced by 58%-65%, excluding the use of nematicides—nematodes
are a particular problem of potato production. Herbicide use has largely been
replaced by mechanical control, band spraying or low dose techniques. The number
of chemical weed control interventions decreased by a third and the amount of
spray was reduced by 25-50%. Fungicide use has been reduced by 80% by using
resistant varieties, a moderate nitrogen supply and threshold and decision
support systems. Insecticide use was also reduced by 80% due to low insect
pressure, the use of control thresholds and low-dose techniques. Growth
regulators were only used in sowed onion.
The feasibility behind this approach is
to score pesticides on their potential presence in the abiotic environment, and
to substitute less dangerous pesticides, lower dose rates, more directed
applications (band spraying) or non-chemical measures.
Development or maintenance nutrient
reserves in soil is required to maintain quality production. Hedge, ditch and
field margins allow wild species and beneficial species to establish themselves.
Conclusion
Detailed economic analysis of IFS shows comparable or
better results than conventional farming. However, farm size has to be enlarged
to realise net profitability.
Integrated farming experiments have a
solid track record in the Netherlands. Now IFS is being established in
mainstream farming. Significant planning and management is required to make it a
success. With more farmers taking up IFS the ability of research stations such
as Nagele to provide extension support will become stretched. On the other hand,
well-established IFS techniques can be passed on quickly, freeing researchers
and extension staff to address new problems which farmers may face.
The next issue of Pesticides News will focus on integrated farming in Denmark, Sweden and Germany.
[This article first appeared in Pesticides News No. 25, September 1994, page 9]