So, consistent with previous research, the study finds that trees can use water more efficiently when there's more carbon dioxide in the air, which makes their rate of photosynthesis increase.
When simultaneously exposed to light of both wavelengths, the rate of photosynthesis is far higher than the sum of the red light and far red light photosynthesis rates.
Add to this, the fact that the rate of photosynthesis of crops varies as they reach maturity means that you need more complex systems to actively manage the atmospheric composition.