Atfarm uses data from Sentinel 2 satellites to calculate a vegetation index which we call N-Sensor biomass index. In Atfarm we then run follow-up calculations to generate variable rate nitrogen prescription maps per pixel of the selected field on a 20 by 20-meter grid (note: on very large fields, grid size can vary). This procedure ensures high accuracy as the N rates are calculated on a grid-cell basis. However, it might lead to drastic changes in the application rates from grid-cell to grid-cell. We call this mode the raster map.
Especially when driving fast, or in a diagonal path to the grid direction, this leads to frequent changes in the application rates. When using the drive mode in the Atfarm mobile app, this might lead to misapplication and frustration as the rates might change faster than you could adjust the rates at your terminal.
Therefore, we also allow using the zone map. The zone map is based on the raster map, but it calculates clusters of similar values to reduce the number of rate changes while driving on the field. This obviously limits the accuracy of the variable rate map, but it increases usability and therefore accessibility of precision fertilization.
For both, zone map and raster map, we allow you as the user to edit the prescription map before exporting as you have additional information about your field. To edit the map, just click on one of the dots/squares on the left side panel. You can also alter the N rates per color cluster individually if you desire.