I made a couple of NDVI images of the beans which had been greatly improved using compost compared to those grown without. The principles of NDVI as based on that
Generally, healthy vegetation will absorb most of the visible light that falls on it, and
reflects a large portion of the near-infrared light. Unhealthy or sparse vegetation reflects
more visible light and less near-infrared light. 1
Knowing that, it’s possible to see in the NDVI image that the compost-grown beans do seem to be reflecting more IR relative to visble light, I find this easier to qualify from the greyscale image
There’s also hardly any IR patchiness within individual leaves in the compost-extract assisted plants at the back compared with the plants in the foreground – all were planted at the same time.
The polytunnel with the tomatoes was treated entirely with compost extract, because of this we have no control. The tomatoes look good
with this chart showing why the difference between IR and vis reflectivity is key