How can I compare the biomass of one or two fields between two selected dates?

The comparison view allows you to compare one or two fields between two selected dates to benchmark growth, identify anomalies and strategise actions. Follow the steps below to compare biomass.

1) Open monitoring mode

1. Open YaraPlus Atfarm:
   • Web app: Hover over the sidebar to expand the menu and select Atfarm.
   • Mobile app: Tap Discover in the bottom bar, then select Open Atfarm.
2. Select the field you want to monitor:
   • Web app: Select the field from the left navigation bar.
   • Mobile app: Select Fields from the top navigation bar, then select the field from the list.
3. The field page opens with the latest biomass map.
4. Open monitoring mode:
   • Web app: Click Open monitoring mode.
   • Mobile app: Tap the expand icon on the map.
5. Open comparison mode:
   • Web app: Click Compare fields in the upper right corner.
   • Mobile app: Tap the comparison icon next to the field name.

2) Select fields, map type and date

You can see two maps showing the field with a biomass layer applied to the satellite image taken on each of the selected dates. On mobile devices, you can switch between the two maps using the field tabs at the top of the map.

You can switch between different satellite maps and biomass maps and view them for a specific date. In Central Europe, a new satellite image is usually available approximately every three to five days.

1. Select the fields:
   • Web app: Click Change field above each map and select a field from the list.
   • Mobile app: To switch between the maps, select Field 1 or Field 2 from the tabs at the top of the map. Then, at the bottom of the map, tap the pen icon next to the field name and select a field from the list.
2. Select a map date:
   • Web app: In the bottom box, select a date under Satellite map date.
   • Mobile app: Swipe up the bottom sheet, then select a date under Satellite map date.
   • Biomass maps require clear satellite imagery. A cloud detection algorithm filters out cloudy and snowy images, so you can only select clear images (marked with a 🔆 icon).
3. Select a map type:
   • Web app: Click the map icon in the bottom box, then select a map.
   • Mobile app: In the bottom sheet, open the Satellite map type dropdown and select a map. 
   • Each biomass map uses a different colour scale (shown at the bottom) to display in-field variability.
   • If no crop type is assigned, Optimised map and N-uptake map are disabled. How to add a crop type
4. If there hasn't been a clear image for more than five days, you can estimate the biomass development using a cloud-free image from up to 21 days ago, based on weather and recent crop growth. Click Generate map to create a more recent map. How the estimation works

3) Monitor biomass on the map

You can now view the selected maps for the selected fields and dates. On mobile, swipe the bottom sheet down to see the maps again. You can then switch between the two maps using the field tabs at the top.

• Move the map:
  • Web app: Click and hold, then drag.
  • Mobile app: Drag the map with your finger.
• Zoom in and out:
  • Web app: Use the mouse wheel or the + / - buttons.
  • Mobile app: Pinch to zoom.
• Adjust map transparency: Use the Map transparency slider to make the biomass overlay more transparent and check what's visible underneath.
  • Web app: Use the slider in the bottom-left box.
  • Mobile app: Swipe up the bottom sheet, then use the slider.