GPS/GIS Applications in Agriculture

Gary T. RobersonAgricultural Machinery Systems

GPS/GIS Applications

Guidance Point Guidance Swath Guidance

Control Variable rate

application Variable depth

tillage Variable irrigation

Mapping Soil properties Chemical

Application Chemical

Prescriptions Tillage Maps Yield Mapping Pest Mapping Topographic Maps Planting Maps

Field Mapping

Position data (georeference data) recorded at predetermined intervals.

Other data recorded manually or automatically by monitor, computer, or data logger.

Data displayed by geographic information system (GIS) in thematic map format.

Soil Sampling

Georeferenced soil samples can be collected

Sampling Methods Grid sampling: intensive sampling of

entire field Directed sampling: intensive

sampling of particular target areas

Grid Sampling

Data collected for each cell or point

Multiple samples combined into each cell or point sample

Directed Sampling

Sampling zones established based on knowledge of field

GPS used to locate sample points.

Areas of interest intensely sampled, others lightly sampled

Crop Maze

Field Boundary, Vollmer Farm, Bunn, NC

Crop Maze

Crop Maze

5 acre corn field Creative minds Sub meter DGPS Field computer Mapping software

450 foot tall wolf

Yield Maps

Record of spatial yield variability within a field or farm.

GPS data coupled with yield data to produce map. Mechanically harvested Hand harvested

Useful tool for decision making.

Cotton Yield Map

Field Scouting

Fields can be scouted for a variety of pests

Pest populations recorded on mapsDecision tools can be applied on a

site specific basis

Weed Map

Variable Rate Control

Application rates designed for needs of small sections of a field

GPS determines position of equipment in the field

Computer controls use GPS data and prescription files to adjust rate

Prescription Map