If only everything in life was
straight forward. A simple choice between black and white. In the real
world we must weigh argument, balance risks and make choices. Why
should farming be any different? And yet, for many years, farmers have
been encouraged to adopt a simplistic approach to their inputs of
fertilisers and pesticides.
On the one hand, conventional wisdom advocates
simple recipes like applying x tonnes of fertiliser at a particular
time or following a straightforward three spray fungicide programme.
On the other, organic regimes have strict rules which must be followed
whatever the circumstances and no synthetic pesticides or fertiliser
can be used. Setting universal production standards for something with
as many variables as growing a crop is unrealistic. Far better to work
towards a predetermined objective, but to allow each situation to be
assessed on its own merits so that tactical decisions can be made to
accommodate whatever the season throws at you. This is what we are
doing in the Focus on Farming Practice project.
The CWS pilot farm
Focus on Farming Practice was set up by CWS
Agriculture in 1993 to evaluate integrated farming techniques in a
commercial farm environment. It is seeking to balance the demands of
the consumer for a consistent supply of high quality produce with the
needs of the farmer to make a profit and the desire of both to protect
the environment. The 150 acre (60 ha) site operates on a farm scale,
but in all other respects is run like a small scale experimental plot.
Data is accurately measured and scientifically evaluated and assessed.
A seven year rotation has been adopted. The conventional practices
used in the trial are identical to those followed commercially on the
rest of the estate and, with results also available from our 280 acre
(110 ha) organic trial right next door, we can evaluate and compare
performance across all three farming systems. Uniquely, the project
relies on commercially available advice and practical farming
expertise which means that the thinking behind the methods adopted is
capable of being applied across the whole country. It is testing
theories and providing practical guidance on what does and does not
work but is not trying to establish a blueprint that everybody must
follow.
The philosophy and practice
The fundamental philosophy of integrated
crop management (ICM) is to integrate cultural, biological and
mechanical techniques with targeted intervention with pesticides and
fertilisers. The system attempts, through the use of the former, to
decrease reliance on the latter, so that the cost of inputs can be
reduced and yield and quality maintained. By its very nature
therefore, it is non-prescriptive. Decisions have to be made on a
field-by-field basis. The trick is to design a system which minimises
weed, pest and disease infestations, maintains fertility and works on
your farm. Many farmers are adopting individual ICM methods to reduce
costs, but it is the holistic approach which is showing the greatest
potential.
Lessons from the organic approach such as using
crop rotation to improve soil structure and fertility and to help
reduce the spread of some pests, diseases and weeds are applied. Crop
varieties are chosen for their disease resistance, standing power and
vigour to compete with weeds. In the integrated system however, these
organic methods are supplemented by the targeted use of inputs.
Crop protection products are used where economic
loss is threatened. They are selected according to strict criteria. We
look at mammalian toxicity, persistence of the product, volatility,
selectivity and , on our site most important of all leachability. All
our fields drain directly into rivers so the pesticide levels in any
run-off or percolated water are important. We are monitoring these
levels. There is a trade off between leachability and persistence
which must be taken into account. We do not want a product that stays
around in the soil or on the crop. We look for as low a rate of active
ingredient as possible too. Some of the herbicides we use are as low
as 20 g/ha (half the normal rate).
Doses are calculated with a view to suppressing the
antagonists rather than removing them completely. We have never yet
applied full label rate of any pesticide. In deciding how far we can
reduce the dose however we need specialist knowledge so that we can be
sure that, given the development stage of the antagonist, the weather
conditions and so on, the treatment is going to be effective. Putting
a low dose of pesticide into the environment for no crop benefit at
all is plainly pointless and downright irresponsible. I believe that
to get the best from pesticides farmers need much greater access to
product data. For example if you are adopting a policy of cultivations
which is designed to increase earthworm populations you need to know
whether the pesticide you plan to use is going to have any undesirable
effects. Such data exists, as part of the product registration
package, but is not normally made available to growers.
Environmental monitoring
Hand in hand with these techniques is an
ambitious environmental monitoring programme in which we are measuring
the effect of changes brought about by the integrated approach. As yet
it is too early to claim widespread benefits but there are some very
encouraging signs. Earthworm counts for example are showing that the
minimal tillage techniques that we use are much less disruptive. Of
course all farming disrupts the natural environment and in my
experience that includes organic systems. Mechanical weeding can be
very damaging to ground nesting birds and I am concerned at the
potential for nitrate leaching when grass clover mixtures are
ploughed-in to improve fertility of the soil.
Farms of the future
ICM has been accused of being a ‘green’
marketing tool; a cynical means of selling produce to the public. I
strongly disagree. Produce grown under an integrated regime will not,
indeed should not, command a price premium. It is a standard to which
every grower should aspire. In five to ten years time, integrated
production will be the norm. The economic imperative will be the
difference between selling and not selling your production, rather
than any niche market ‘green’ premiums.
So far, our research is showing that the site
specific integrated approach is both technically and economically
feasible. It also looks to have good environmental benefits. All that
means it is a realistic and exciting option for the future.
Alastair Leake is the Project Manager for the Focus on Farming Practice project on the CWS Agriculture estate at Stoughton near Leicester, and also manages the CWS Agriculture 280 acre organic farm on the same site .
[This article first appeared in Pesticides News No. 31,March 1996, page 17]