Precision agriculture allows modern producers to manage within fields rather than managing the whole field.By integrating global positioning systems (GPS), variable rate (VR) application equipment, and geographic information systems (GIS), farmers are allowed increased efficiency. However, prior to using VR equipment, accurate maps of yield-limiting factors must be created.

Nutrients in any field vary due to topography, soil properties and past management (manure application patterns, crop history, etc.). To account for this variability, farmers will need more than one soil sample in each field. A more intensive sampling scheme must be performed, through either grid or zone sampling. Looking to the future, on-the-go sensors, whether attached to tractors or unmanned aerial vehicles, may also increase accuracy and decrease the cost of soil sampling.