The biomass monitoring is completely free in Atfarm. After you added your fields, you can see a satellite image with a biomass overlay over your field next to your field details view. In the lower right corner of the satellite image you can find a square. When you click on it, you can choose between the map view (base map, field view) and the biomass overlays (NDVI biomass, N-Sensor biomass).
Which biomass overlay should I select for growth monitoring?
We recommend using the new N-Sensor biomass overlay instead of the NDVI overlay for monitoring the growth of your crops.
NDVI biomass overlay
The NDVI biomass overlay uses the NDVI Index to display differences in crop growth. Before highest biomass the NDVI index saturates and you can no longer recognize differences between highest and lowest growth within a field. The NDVI index is shown on a fixed color scale from very low biomass to maximum/saturation biomass.
N-Sensor biomass overlay
The N-Sensor Index is not prone to saturate as fast as the NDVI and has a better correlation to nitrogen uptake. The new N-Sensor biomass overlay enables to analyze crop growth through the whole growth cycle and even across seasons. The color scale is adjusted to the lowest and the highest index value in a satellite image. Low biomass is represented by brown tones. After 'growing' through a range of greens, when the canopy is fully evolved, it moves into blue and then into purple (some crops). This overlay is useful to identify growth differences within a field but doesn't allow to compare images of the same field over time.