CO2 Enrichment
- Benefits to CO2 enrichment:
- nitrogen fixation
- increased stem thickness
- increased leaf area
- increased shoot weight
- increased leaf weight
- increased plant height
- accelerated root growth
- early flowering and fruiting
- increased flower weight
- shorter cropping cycle
- increased water use efficiency
- increased resilience to the stress of pollutants, temperature fluctuation and drought
- The atmosphere has 340 ppm (parts per million) of CO2. That is 0.0036%
- Plants breathe in carbon dioxide and breathe out oxygen
- Plants benefit from CO2 increases up to 2000ppm
- The optimum level of CO2 for most plants is between 800 and 1350 ppm
- 90% of growth increase is obtained with the first 1000 ppm of CO2 in the atmosphere
- One cubic metre at 1000 ppm contains one litre of CO2
- Every cubic metre must have between half and one litre of CO2 added to optimise CO2 level
- If you add one litre of gas to a cubic metre of air, the CO2 level will be (1000 + 340) = 1340 ppm
- Optimal temperature is 21 to 27 degrees
- Growth rate slows markedly if the ambient temperature rises above 35 degrees or falls below 21 degrees
- When the temperature reaches 35 degrees, the benefits of CO2 enrichment become zero
- Excessive heat reduces the ability of the plants to absorb CO2
- The only air conditioner suitable is a refrigerant one. Set to recycle, not draw in from outside. An evaporative air conditioner will absorb CO2 from the air, wasting it
- Levels above 2000 ppm are detrimental and become toxic to plants
- Work-safe recommends humans are not exposed to 5000 ppm (averaged) over an eight hour period. Plants begin to die at this level
- Properly seal room (especially around the extraction fan) so CO2 won’t escape through leakage
- Set your CO2 unit to come on before the light switches on and to turn off just as the light switches on. When the light comes on, the room will contain optimum CO2 in the air that the plants can use immediately
- Place your CO2 unit on a shelf, desk, cupboard etc. Never sit your unit on the floor