The adoption of global positioning system (GPS) technology to fine-tune agricultural field operations over the last decade has been unprecedented relative to other agricultural technologies. Resultantly, as agricultural machinery size and capacity increased, field operations have become much more precise due to the synergistic relationship between farm machinery and GPS-enabled guidance technology. With increased dependence upon GPS technology, one must ask “What are the risks associated with becoming wholly reliant upon electronic machinery that is bound to fail from time to time?” This question can be partially addressed by estimating the economic cost of reverting from GPS-enabled navigation technologies, such as manual lightbar (LB) assistance and automated guidance, to traditional visual marker (VM) references. For the purposes of this scenario, economic cost will be defined by the summation of changes in fuel, labor, seed costs, and yield penalties associated with being forced to revert to status quo VM technology for one day during the planting season. This analysis illustrates the strengths of GPS adoption as well as highlights key pitfalls.
To address the economic feasibility of GPS navigation technologies, a mathematical linear programming (LP) model was formulated for a representative 1,214 hectare U.S. Cornbelt farm. Several scenarios were compared: 1) a baseline scenario with foam, disk or other visual marker reference without GPS navigation; 2) LB navigation with basic GPS availability of +/- 3 dm accuracy; 3) automated guidance with satellite subscription correction; and 4) automated guidance with a base station (RTK) and +/- 1 cm accuracy. Evaluation of whole-farm returns over incremental management scenarios builds upon previous research by evaluating the changes to inputs costs. This study is of interest to farmers considering the best use of precision technology, agricultural industry marketing the technology, university researchers searching for optimal management of technology, and agricultural and international policy makers.
