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Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Agricultural Engineering


Field Grid Sense (FGS) is a system developed for use with a laptop computer to control crop production inputs. FGS can be used for spatially controlling and recording field inputs according to regional requirements within the field. Location is identified via the travel lanes formed during field operations. Grid areas within lanes are formed by measuring from the beginning of each lane to the start of each grid within the lane. Distance measurements are reset at the beginning of each lane in order to eliminate accumulated distance error in the field. A fifth wheel, which runs in the smooth path created by the front tractor tire, is used for distance measurement. 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 for controlling/recording granular or liquid fertilizer rates, sprayer applications, seed planting rates, crop yields, and/or any field input/output that needs to be spatially managed. A system for controlling granular chemical was initially designed and assembled; the gate position on a granular applicator being automatically adjusted via software to the proper setting upon entering each new grid area. The system was taken to several fields, where it was activated and operated as designed. Preliminary tests were conducted on the distance measuring accuracy of the fifth wheel technique. Initial results obtained from 142 field trials showed a fifth wheel field slip of between ± 0.84% when the rolling circumference of the wheel was set at 1.554 m (5.097 ft.) (the median test value from all data). The trials were conducted on three soil types loam, clay, silty clay loam. A relative slip value of ± 0.84% translates into a distance error of ± 2.56 m (8.4 ft) over 304.8 m (1000 ft).

Library of Congress Subject Headings

Fertilizer equipment
Field experiments -- Computer programs
Farm management -- Data processing
Agriculture -- Data processing
Crops and soils -- Computer programs



Number of Pages



South Dakota State University