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Public concerns about pesticides have encouraged some governments to develop policies and strategies for the reduction of pesticide use. Some of these efforts have produced significant results. Others have not.
There are many reasons for these mixed results. In some cases, support for pesticide reduction seems largely rhetorical. In others, policy makers are truly dedicated to reduction, but have employed strategies that are insufficiently comprehensive.
A stated commitment to Integrated Pest Management (IPM) is central to most pesticide reduction programs. The problem lies in the way IPM is defined and implemented. In many IPM programs, synthetic pesticides remained the chief tool in the control strategy, so significant reductions have not occurred. With others, some attempts are made to integrate pest prevention strategies into the plan, but success is limited by a lack of knowledge about suitable cultural practices among those implementing the programs. Unfortunately, most governments have not supported the development of IPM pesticide reduction programs within an ecologically-based sustainable agriculture framework.
A useful framework for determining whether IPM strategies are consistent with a sustainable approach to agriculture is Stuart Hill's Efficiency - Substitution - Redesign model (ESR)1. Classifying pesticide reduction strategies within the ESR spectrum is helpful for gaining a perspective on how different approaches contribute to sustainability. At EAP, we find ESR helps us in identifying what changes in farm management strategy are most important to encourage.
As its name implies, strategies that fall within the Efficiency stage (stage 1) of the ESR are characterized by their focus on the fine-tuning of existing practices to reduce consumption and waste. On the farm, examples of this approach include the refinement of spray schedules to eliminate unneeded pesticide applications, the use of electrostatic sprayers to increase the percentage of pesticide reaching target plants, and the use of pesticides that act more narrowly and effectively on the target pest.
In the Substitution phase (stage 2), there is a more profound shift towards sustainability. Resource-dependent and environmentally disruptive products and procedures are replaced by those that are more environmentally benign. Scouting, biological controls and low-toxicity pesticides (such as diatomaceous earth) may replace the routine use of conventional pesticides.
Finally, when farm management starts to move into the Redesign stage (stage 3), a more holistic approach that fosters long-term sustainability is achieved. Instead of responding by trying to minimize the symptoms of a problem, the causes of problems are explored using a systems approach. By recognizing the complexity of the interactions within a farming system and redesigning the whole system, problems are prevented – being solved internally by site and time-specific design and management approaches instead of by the application of external inputs. Complex crop rotations, interplanting schemes, alternate hosts, and use of animals for pest control are all examples of potential elements of a redesign strategy. By making the farm more ecologically and economically diverse, greater resource efficiency and resilience are achieved.2
Based on this framework, we contend3 that many innovations within conventional agriculture (including most current pesticide reduction strategies) provide only a first step to achieving sustainability. Efficiency stage strategies certainly receive the most attention at this point, and do move us in the right direction. However, their capacity to help us achieve sustainability is ultimately limited. Substitution strategies take longer to develop, but can move us further. Redesign strategies are the most poorly understood at this point and receive the least attention, but ultimately they will be the key to long-term reductions in pesticide use—and a sustainable agriculture.
Of course, in reality, neither farmers nor policy makers proceed systematically from one category in the ESR spectrum to another. Rather, some practices and strategies have elements that fall into different categories. It is, however, informative to classify the relative sustainability of a pesticide reduction program using the framework provided by the ESR categories. By studying the many different IPM programs being used around the world in this way, we can gain a better understanding of the real potential for the reduction of pesticide use in the short, medium and long term.
Evidence from many countries supports the idea that IPM programs using proven strategies, primarily in the Efficiency and Substitution stages, can produce pesticide reductions of 50%.
Pretty has summarized IPM program pesticide reductions, resulting yields and annual program savings, with an emphasis on those programs "concerned with developing farmers' own capacity to think for themselves and develop their own solutions".4 With data from Asia, Africa, Latin and North America, Pretty shows how 50% reductions in pesticide use are feasible, with yields frequently higher than under conventional regimes (90-135%) and savings of millions of dollars.
Sweden, Denmark and Norway have also demonstrated significant reductions. Although some of these are a product of the way reduction is measured, the evidence clearly supports the feasibility of 50% reductions within 5 years.5
In Indonesia, pesticide use in rice reportedly dropped 65% between 1987 and 1992 and rice yields increased 15% during that period.6
Pimentel et al7 concluded, in an analysis of 40 crops in the USA, that a 50% reduction in pesticide use is possible. They projected greatest reductions in field crop and pasture insecticide use (64%). Lowest reductions were projected for fruit and nut fungicide applications (26%).
The Campbell Soup Company launched a program to reduce pesticide use amongst its growers by 50% within 5 years. In 4 years, it had exceeded this goal for three crops, without reductions in yields and quality.8
In light of these experiences, a 50% reduction in global pesticide use within 5-10 years appears to be very realistic possibility.
Projections from countries currently engaged in pesticide reduction suggest that primarily Substitution stage strategies with some Redesign elements can produce a further 50% reduction in a subsequent 5-10 year period (resulting in a total reduction of 75% over 10-20 years).
The US Congress Office of Technology Assessment concluded over 15 years ago that pesticide use in the USA could be reduced by 75% if IPM were universally adopted.9 The USDA has pledged to promote IPM on 75% of harvested acreage.10 Sweden's plans include a 75% reduction over 10 years, from the 1985 base year to 1996.11
Given the caution of those making these projections, this target appears feasible.
The basis for this reduction target is largely speculative, as few nations are yet attempting reductions of this scale. Redesign strategies are poorly developed at this point. However, with their emphasis on designing pests out of the agroecosystem so that pesticides are not required, they could produce a further 50% reduction beyond those previously discussed, over a 5 to 10 year period (leading to an overall 87.5% reduction over 15-30 years).
Wholesale conversion to organic agriculture is one way to achieve dramatic reductions in pesticide use. Burkina Faso began a program in the mid-1980s to develop food self-sufficiency using ecological food production approaches.12 Cuba13 and Iceland14 are now implementing policies and programs for wholesale conversion to organic agriculture. The results of their efforts will not be known for several more years.
The literature shows that the potential for dramatic reductions in pesticide use is there. Most governments have a poor record of adopting and then achieving targets. Canada, for example, has taken little concrete action in this area, although some provinces have taken initiatives to promote efficiency stage work. The task remains for activists to push for clear commitments to pesticide reduction targets and the implementation of well-designed programs to meet those targets.
Copyright © 1997. Ecological Agriculture Projects.
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