Subject: GPS and Prescription Agriculture
Date: 21 Jan 92 14:48:09 GMT

Background:  Prescription agriculture is a method of farming where instead
             of seeding/fertilizing/spraying the same amount over an entire
             field, an amount appropriate for the slope and soil is applied.
             This can be done by mapping the field and then using the map
             to guide application.  A key difficulty is in knowing where the
             tractor is on the field.  The global positioning system (GPS)
             uses an ensemble of satellites sending coded information to
             triangulate the latitude, longitude, and altitude of a receiver
             to within a few feet. GPS receivers are down to about $1500.

Question:    Are there any Prescription Agriculture GPS papers in recent
             conference proceedings or journals?  I am aware of only one
             project in this area and it is being done by a farmer in
             Indiana.