For an agronomist like Ray Asebedo, the science behind optical sensor technology starts with the premise that plants are visual communicators that “speak” in wavelengths of light. Lush greens are usually indicators of good health, a sign of enough N in the soil system. Yellowing can signal stress.
Optical sensor technologies go a step further and allow for the analysis of light beyond what’s visible to farmers or their agronomists walking the field, scouting crops. For instance, near infrared light has a strong reaction with plant cells and gives a good gauge of plant biomass.
Red and red edge light commonly used from satellite technology, or Trimble’s GreenSeeker or Topcon’s CropSpec, can measure photosynthesis.
“Since red light is heavily absorbed by chlorophyll, it gives us a gauge of photosynthetic capacity,” Asebedo explains. “So between red light, red edge, and the infrared, we can start to see how big that plant factory is, and how efficient it's operating at to produce yield.”
Optical sensor technologies, then, can provide a broader view of what a plant is “telling” us about its interaction with the environment. Also, the introduction of drone technology as a tool about 5 years ago provided a bird’s eye view of a field to get a better sense of variability, Asebedo says.