Ecologically Based Pest Management
Ecologically Based Pest Management
As described in previous chapters, widespread use of conventional synthetic pesticides has significantly impacted ecological resources by killing non-target organisms, contaminating water and soil, and disrupting and destabilizing the natural processes that tend to suppress pest populations. Nevertheless, it is not helpful to focus on the use of these chemicals in isolation. Instead, we must look at the farming system as a whole and recognize that many ecologically detrimental practices go hand in hand. For example, growing monocultures and eliminating crop-patterning practices can increase the need for chemical pesticide inputs. Consequently, to be able to reduce our reliance on chemical pesticides, thereby reducing the adverse ecological impacts resulting from the use of these substances, we will need to consider “whole system” farming practices that utilize and enhance natural processes. Additionally, by employing more ecologically sound farming practices, we will be able to make working farmlands healthy habitats for wildlife that provide of a range of important ecosystem services.
What happens on the farm dramatically impacts what happens to wildlife, biodiversity, and ecosystems throughout the world. If we wish to protect wildlife, biodiversity, and ecosystem services, we cannot simply rely on taking certain lands out of production and putting them in public or private preserves.1 It is simply impossible to put sufficient land in preservation to adequately protect the natural environment. The statistics regarding current acres of land in preservation as opposed to acres of land in active agriculture are telling. Currently, only approximately 5 percent of land on earth is preserved in parks and other protected areas. In stark contrast, agriculture and livestock production comprise roughly 50 percent of the globe’s habitable land.2 Accordingly, farming practices that provide habitat for wildlife, support biodiversity, and preserve ecosystem services can substantially improve the overall promulgation of these values throughout the globe. In this way, agriculture can not only provide food and fiber, but also significantly contribute to the protection of resources and services critical to society.
For several decades, there have been calls to adopt more ecologically sound farming practices. For example, the 1992 book Farming in Nature’s Image, introduced the idea of using nature as a model for agricultural production.3 More recently, much research and discussion has focused on the idea of “sustainable agriculture” or “eco-agriculture.” Specifically with regard to pest management, the concept of looking at the whole farming system and using a diverse variety of natural, enhanced, and supplemented control measures has also been researched and discussed for decades, first as Integrated Pest Management (IPM), and more recently as what is known as “Ecologically Based Pest Management” (EBPM).
Some form of the IPM approach is currently used in many agricultural and non-agricultural settings. The adoption of these approaches has resulted from a number of factors. Interestingly, some of the pesticide regulations that have been most effective in encouraging a shift to more ecologically based practices are not directed at ecological risk, but instead are human health and safety based. For example, EPA’s Worker Protection Standards,4 which impose a number of requirements including prescribing how long after pesticide application a worker must wait before re-entering the field (known as “reentry intervals”), and other restrictions to protect the health and safety of farmworkers, have made certain conventional pesticide application practices impracticable and thus have caused some producers to shift to IPM approaches.5 Other indirect influences that have encouraged some farmers to shift to IPM include other regulations, such as food safety regulations, that are designed to protect human health, rather than the natural environment.6 Thus, continuing to ensure that human health and safety are adequately addressed under pesticide law will likely have the added ecological benefits that accrue from a switch from conventional pest control to IPM. IPM adoption has also occurred in areas where either private “Crop Advisors” or state extension agents have promoted the concept and provided the information, training, and services necessary to implement them. Unfortunately, this has been done on an ad hoc basis. There is great variability in the level of education and interest in IPM among extension agents. Some have been very active in promoting IPM, while others have been reluctant to move far beyond traditional chemical input approaches. In some areas of the country, private sector “Crop Advisors” have developed IPM systems for particular crops and provide the scouting and monitoring services necessary to properly implement the IPM programs. In addition, the federal government and many state and local governments have adopted IPM approaches in their own pest management practices. IPM is now widespread on military bases, on public lands, in public schools, and in other government-run facilities. Moreover, certain large food retailers, including Wal-Mart, Wegman’s, and Gerber are starting to include in their contracts with food producers requirements that all foods sold to the retailer be grown using organic, IPM or other environmentally sound approaches.7
In the mid-1990s, at the request of the USDA and with support from EPA, the National Academies, National Research Council (NRC), convened a committee on “Pest and Pathogen Control through the Management of Biological Control Agents and Enhanced Natural Cycles and Processes.” The committee was charged to “assess the status of the knowledge in areas of pesticide application, host resistance, and biological control practices and to chart future direction.” In 1996, the NRC published the findings of the committee in a report entitled “Ecologically Based Pest Management: New Solutions for a New Century.”8
Bridge Document 14.1 Ecologically Based Pest Management: New Solutions for a New Century
Given our charge and the record of history of the application of pesticides, breeding for disease resistance, and integrating biological control practices into production agriculture, my colleagues on the committee and I deliver this report with one key message: In both science and application, researchers, providers of inputs and growers must progress from a product based approach to an ecologically based pest management system identified as EBPM. Management is the key word. In fact, the word control, as in biological control is misleading. Pests in most cases cannot be controlled; pests must be managed with the objectives of a safe, profitable, and durable outcome.
With a better understanding of ecology, the inherent strengths of the managed ecosystem can be used with more modest inputs than in the past. Essentially, the change to EBPM as proposed here will require a substantial change from the primary practice of product input to the primary mind set of information and management. Ultimately, EBPM will help to address ecosystem health not by administering products alone to treat systems, but by integrating components that maximize use of natural processes with minimum development of resistance.
EBPM will require regulatory oversight that matches the level of risk of biological inputs added to the managed ecosystem. For example, synthetic chemicals are new to the biosphere—they have no base of performance in the environment or in relation to human health. However, biologically based organisms, products, and resistant cultivars are inherently different, for the most part, from synthetics. Biological processes, having existed in nature over time, provide a base of experience that is a major resource to evaluate the safe application and establish appropriate oversight of EBPM …
The NRC report focuses on the problem of pests developing resistance to synthetic chemical pesticides, which currently limits the efficacy of many chemical pesticides and has eliminated any viable chemical control for some pests.9 When natural controls are removed from a system, through growing monocultures and reducing predator and parasite populations with the use of chemical pesticides, farmers become dependent on continual use of chemical pesticides. Over time, pests are likely to develop resistance to the chemicals used, rendering the chemicals ineffective and creating an increasing need for additional chemicals. Thus, the NRC committee concluded, “[t]here is an urgent need for an alternative approach to pest management that can complement and partially replace current chemically based pest-management practices.”10 The report emphasized the need to create “whole-farming” systems, which integrate pest management with fertilization, cultivation, cropping patterns and other ecologically based production practices.11 The foundation of EBPM, promoted in the report, is using inputs of knowledge of the managed agricultural ecosystem, including knowledge of pests and their natural enemies, with physical, chemical, and biological inputs as supplements. The report articulates the objectives of EBPM as “the safe, profitable, and durable management of pests.”12 The report criticizes conventional chemical input farming as disrupting and destabilizing the natural processes that suppress pests.13
Although the term “EBPM” may be relatively new, many of the mechanisms used in EBPM harken back to the pre-chemical history of agriculture, where cultural and biological controls dominated. Thus, cultural practices such as rotating crops, intercropping, choosing pest resistant crop varieties, and promoting the development of healthy soils are key components of EBPM. These practices enhance natural pest control processes. With decades of research on pests and pest management, as well as the development of new technologies, however, EBPM can build on and move beyond the pest management practices relied upon in the pre-chemical era.