Field Grid Sense is a new system developed for use with a laptop computer to control crop production inputs. The system spatially controls and records field inputs according to regional requirements within the field. Location is identified via the travel lanes formed during field operations. Application rates are predetermined for each field region and stored on computer diskette. The application is adjusted to the assigned value during field operations. This system can be adapted to control/record granular fertilizers, direct chemical injection systems, liquid fertilizers, seed planters, crop yield maps, and/or any field input that needs to be spatially managed.The use of equipment and/or products in this study is not intended to endorse or discredit the manufacturer or product by the researchers, SDSU, and/or SAE. This pulication has been approved by the South Dakota Agricultural Experiment Station as Journal Article No. 2509.