environmental benefits should be expected in areas where fertilizer inputs are matched to crop needs. It is logical to conclude that precision agriculture should incorporate similar approaches to fertilization. The potential of precision agriculture technologies to reduce pesticide applications is still not well known. Some benefits may accrue from localized herbicide treatments. Precision agriculture may also lead to increases in input use, for example, by making profitable the expansion of crop production onto more vulnerable land, or by documenting prior underutilization of fertilizers or pesticides. More research will help to assess the environmental effects of management of small units compared with whole fields. Such research should concentrate on broader-scale effects, however, such as impacts at the watershed or ecosystem levels. It is by no means apparent that effects at the field level scale up to broader levels in any readily predictable ways.
Finally, experience with previous information-intensive technologies suggests that improvements in environmental quality will likely constitute a significant incentive for farmers to use precision agriculture only if producers bear at least a portion of the costs of agricultural pollution. Precision agriculture is thus unlikely to be a panacea for environmental problems in agriculture in the absence of other regulatory measures.