Precision agriculture has been gaining acceptance and use in some areas of the country and continues to grow across the Cotton Belt. Utilization of Global Positioning Systems (GPS) and Geographic Information System (GIS) make it possible to geo-reference fields which become the framework for multi-layered data that can be used to help explain events occurring in a particular field or management zone. This study on 15-acre field at the Delta Research and Extension Center was initiated in 1998 in an effort to evaluate the spatial variability of corn and cotton yields as well as the soil characteristics measured in the same areas. Corn grown in 1998 had yields which ranged from a low 132 bu/A to a high of 186 bu/A and a field average of 156 bu/A. In 2000, the same area had corn yields which ranged from 151 bu/A to a high of 222 bu/A and a field average of 182 bu/A. The area was rotated to cotton in 1999 following the corn crop of 1998. Yields in general were higher following the corn crop than they had been in previous years and were much higher than surrounding fields of continuous cotton. First harvest yields ranged from 900 to 1439 lb lint/A with an average of 1163 lb lint/A. Second harvest yields ranged from a low of 33 lb lint/A to a high of 208 lb lint/A and a field average of 86 lb/A. Total lint yields ranged from a low of 949 lb/A to a high of 1508 lb/A and an average across the field of 1248 lb/A. The range of 562 lb lint/A represented a range of nearly 60% across the field. In 1999, maturity measured as percent first harvest (PFH) ranged from 81.5% to 96.8% with a field average of
93.1%. With the data collected and analyzed to date, it is apparent that the yield controlling factors are complex and are also not consistent from crop -to-crop or year-to-year. The next step is to look at correlations and relationships between the yield and yield components and soil characteristics which will be the scope of the second manuscript in this set. While the technology is new and shows potential, many questions and concerns are yet to be answered. The new technology does provide many useful tools for examining the variations occurring in the field