in a tractor cab communicating with separate rate controllers for seeds, liquid, and dry chemicals). Standards affecting data and hardware interchange affect the integration and ease of using these new technologies. Precision agriculture is technically possible today, in large measure, but requires a high degree of technical know-how and persistence, much as did the early personal computer systems.

Precision agriculture developers and vendors are torn between conflicting goals of responding to user needs and maintaining proprietary advantages, market niches, and demand for system and electronic consulting services. There are also some potential conflicts between publicly provided services and private vendors.

Most concerns in precision agriculture relate to spatial data standards, because many aspects of conventional database management and operating systems already have information technology standards developed by industry and public consortia. These include:

• government standards (i.e., the Federal Geographic Data Committee's Spatial Data Transfer Standard and ISO 8211),

• consortium standards (i.e., the Open GIS Foundation and the Agriculture Electronics Association [AEA]), and

• ad hoc or default standards (i.e., from dominance in the market, such as AutoCad DXF or Arc/Info Export).

Several paths of development and implementation could take place, with different trade-offs in timeliness, responsiveness, and enforceability.

In the arena of precision farming, the Agricultural Electronics Association was founded by the Equipment Manufacturers Institute in 1995 to bring together diverse interests in the field of electronics in agriculture. Membership has grown from 19 original members to over 100 companies, organizations, users, and university and government liaison members. Subdivisions within AEA include a User Council, Equipment Council, Hardware Council, and Software/Information Systems Council. AEA identifies, develops, and facilitates appropriate action to increase compatibility and interchangeability of electronics and information systems used in agriculture. AEA has made significant strides in promoting standardization, including addressing issues such as

• the interface between electronic equipment and specific connector, data, power and protocol requirements;

• compatibility of electronics and information systems with precision farming software;

• a standardized data ''reader" interface between chemical labels and machines;

• environmental standards;

• livestock issues;

• development of a database standard;