Knowledge
Climate · 5 min
CO2 enrichment: when it pays and when it does not
Pushing CO2 to 900ppm boosts tomato yield 18% only when light and temperature also rise. Otherwise you are venting money.
C3 crops (tomato, cucumber, lettuce) photosynthesise faster at elevated CO2, but only if PAR is above 300 µmol/m²/s.
On cloudy winter days, supplemental CO2 has near-zero effect. Tie enrichment to a light-integral threshold, not a clock.
Cap concentrations at 1000ppm. Beyond that, returns flatten and grower health risks rise.