with those of the first, second, or third generations of transgenic crops would be a highly speculative enterprise. Yet in retrospect it is difficult to argue that Green Revolution impacts on the environment were automatically safe, benign, or even acceptable simply because they were developed using conventional breeding. With the potential for introducing additional novel traits through nontransgenic methods, it becomes increasingly difficult to defend the idea that conventional crops should automatically be excluded from scrutiny for environmental impact.

As noted earlier, NRC reports have consistently found that use of recombinant DNA technology in the development of an agricultural crop does not in itself create a new class of risks. As with conventionally bred crops, it is the phenotypic characteristics of the plant that are the source of environmental risks. This report and the 2000 NRC report (2000c) on pest-protected plants cite a number of environmental risks that should be accounted for in the regulation of both current and future crop varieties. When these observations are combined, the possibility that nontransgenic crops may also pose environmental risks requiring a regulatory response becomes logically inescapable. Yet new crop varieties posing potential hazard fail to require regulatory scrutiny under APHIS while potentially benign transgenic crops do because APHIS oversight excludes conventional crops. Those plants produced via recombinant DNA are regulated, and those produced by other methods are exempt, even if the final product has an identical phenotype and therefore presents similar potential risks.

Moving beyond the realm of crop modification, it is also clear that the bar has been raised substantially for acceptable environmental effects for novel pesticides and new agricultural practices (e.g., changes in crop rotations and changes in cultivation practices). As our perspective on the ecological interactions and interchange between agricultural and nonagricultural lands evolves (see Chapter 1), the environmental standard being set for transgenic plants may be a better overall environmental effects model for agriculture than the model developed in the early 1900s for assessing the acceptability of conventional crop varieties and agricultural practices.

Although government regulation of conventionally modified plants has been virtually nonexistent, the agricultural research establishment has not ignored the potential of genetic modification of crops to result in environmental change. Indeed, some of the work begun in the 1960s to assess the long-term impacts of Green Revolution cultivars and cropping practices demonstrated insight into the needs for examining environmental effects on long and large scales. As discussed in Chapter 1, it was only because of long-term 30-year experiments on the impact of cropping intensification that researchers were able to clearly document the effects of

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