tainers. Closed systems are being developed for many pesticides through minibulk systems and innovative water-dissolvable bags, which virtually eliminate exposure of the applicator to the pesticide during mixing. Furthermore, many companies are providing returnable containers, such as the “minibulks” (refillable tanks that holds typically 50 to 100 gallons of pesticide) that greatly reduce disposal costs and risks associated with the disposable smaller 2.5 gallon pesticide containers (Frei and Schmid 1997). A closed system greatly reduces exposure to the pesticide because the pesticide flows from the storage tank directly into the application device (the sprayer) and only does so if the container is properly connected to the sprayer. Additional work needs to be done in these technologies to reduce the risks even further.
Precision agriculture can be defined as a bundle of technologies designed to adjust input use to variations in environmental and climatic situations over space and time so as to reduce residues associated with input use. Many of these technologies rely on space-age communication and incorporate the use of global positioning systems. Modern irrigation technologies that adjust input use according to variability in soil and weather conditions and rely on weather stations and moisture-monitoring equipment are also examples of precision technologies. Precision technologies have the potential to increase input-use efficiency, increase yields, and reduce residues of chemicals that can contaminate the environment. In many cases they can lead to input saving; but in others, the yield effect can also entail increased input use (NRC 1997).
There has been substantial variation in rates of adoption of what can be generically defined as precision technologies. Some modern irrigation technologies have high rates of adoption in high-value crops. Some components of precision agriculture, such as yield monitors, are gaining acceptance among grain producers. But overall rates of adoption of many components of precision agriculture have not been high (NRC 1997). Although some of the technologies can be obtained through consultants, adoption can be hampered by the cost of investment. Furthermore, the management software needed to take advantage of this highly technical information has not been fully developed. Assuming that management software does become available, adoption of precision farming technologies is likely to accelerate as their costs decline and productivity increases are demonstrated.
Precision technologies will allow farmers to take advantage of a wider arsenal of pest-control tools, to adjust application rates, and to target areas where pest problems are most severe. Because agricultural pollu-