BackgroundAs farms continue to grow larger in the midwestern US, it becomes more difficult for producers to adequately monitor or scout all of their crop acres. Scouting is an important step in crop production because it allows producers to identify field areas that may have production problems.

Problem areas may result from several factors, including soil fertility, drainage, and weed or insect infestations. Timely identification of these areas may either result in an immediate remedy, or simply a change in management for the following season. Personal data assistants (PDAs) are handheld computers that may be used to view remotely sensed images. When coupled with a global positioning systems (GPS) receiver, PDAs and remote sensing may help to locate problem areas in production fields.

 Applications and Economic and Environmental Benefits Precision farming data layers such as yield, soil electrical conductivity, or remotely sensed imagery may help provide a better assessment of field conditions than traditional 'windshield' methods of scouting. Any or all of these data layers may be loaded on a PDA coupled with geographic information systems (GIS) software and used for identifying problem areas (Figure 2).

In some cases, problems are not evident from the road but are highly visible in the field (Figure 3). PDAs used in conjunction with GPS/GIS can also log sample points or record the locations of problem areas, and guidance features enable producers to return to these areas for further observation. Directed scouting methods of this type can save producers time and effort.

Another function of the PDA/GPS/GIS combination is the ability to accurately determine the size of problem areas, resulting in targeted applications that benefit both the producer and the environment.