Step 7: Crop sensing
Crop sensing means viewing a plant with sensors. The plant absorbs part of the sunlight or emitted light (from a sensor), the other part is reflected. On the basis of the amount of light that this plant reflects, vegetation indexes can be measured, such as the NDVI, WDVI and REP. These indexes can then be converted into biomass and chlorophyll maps. These maps show a plant's growth and nitrogen needs. On the basis of these cards, it can be decided, for example, whether and how much still needs to be fertilized. An example of a biomass map is shown below.
At Van den Borne potatoes, Fritzmeijer sensors are used, these sensors are mounted on the sprayer and on a number of tractors, so that a lot of data is collected about the growth of the crop during the growing season.