Editing Soil test (section)

=== Geographic distribution of samples for precision agriculture ===
In [[precision agriculture]], soil samples may be geolocated using GPS technology in order to estimate the geospatial distribution of nutrients in the sampled area. The geolocated samples are collected using a distribution and resolution that allows for the estimation of the geospatial variability of the soil area where the crop will be grown. Many different distributions and resolutions are used, depending upon many factors including the goals of the geospatial nutrient analysis and cost of sample collection and analysis.<ref>{{Cite web|url=https://cropwatch.unl.edu/ssm/soilsampling|title=Soil Sampling for Precision Agriculture|date=2015-09-17|website=CropWatch|language=en|access-date=2019-05-22}}</ref><ref>{{Cite web|url=https://crops.extension.iastate.edu/using-precision-agriculture-improve-soil-fertility-management-and-farm-research|title=Using precision agriculture to improve soil fertility management and on-farm research {{!}} Integrated Crop Management|website=crops.extension.iastate.edu|access-date=2019-05-22}}</ref>

For example, in the United States corn and soybean growing regions a grid distribution with a resolution of 2.5 acres per grid (one sample for each 2.5 acre grid) is offered by many precision agriculture soil test service providers. This is generally referred to as grid soil testing.