Garden & Greenhouse


CO2 Monitoring for Greenhouse Applications

Posted January 10th, 2018 by Robin Nichols in

The levels of carbon dioxide in combination with temperature, humidity, and light intensity are the most important factors for the quality and productivity of plant growth in greenhouses. Constant monitoring of these environmental conditions provides data to the grower to better understand how these factors affect growth and how to increase crop productiveness.

Carbon Dioxide (CO2) is one of the key ingredients of photosynthesis, it is essential for plant growth. Monitoring CO2 in a greenhouse allows for optimization of environmental conditions, resulting in more efficient plant growth and higher crop yield. Different plants need different levels of CO2 in the air to maximize development.

CO2 and Photosynthesis

CO2 is a natural gas, in high concentrations; it is dangerous for humans, but essential for plant development. Photosynthesis is the process which involves a chemical reaction between water and CO2 in the presence of light to make sugars for plants, and as a by-product releases oxygen in the atmosphere. Carbon dioxide is a colorless and odorless gas in the atmosphere but has an important role in sustaining life.

The plant growth rate is greatly influenced by the CO2 concentration in the greenhouse, therefore CO2 levels need to be monitored and controlled for optimal development. The CO2 concentration needed depends on the plant type, with the optimal growth level being 1,000 ppm (parts per million) for most crops. Active photosynthesis can bring down the greenhouse CO2 concentration to a level of 200 ppm, which is low enough to negatively impact the plant growth.

Too low CO2 level limits growth but a too high level of CO2 is not beneficial either. Plants are more sensitive towards high CO2 concentrations than humans and show damages like burnt leaves at elevated CO2 levels.

Wireless Technology

Many new wireless monitoring solutions are available to growers. These systems normally consist of base stations with connectivity to the cloud or built-in local web servers for data storage and analysis, along with wireless sensors that measure different environmental parameters such as CO2.

Applying sensors in greenhouses provides constant monitoring of the chosen parameters. Wireless monitoring solutions offer centralized critical real-time data gathering and the ability to use software for data viewing, analysis and comparison any time from any device. New technology helps make the installation process easy, quick and cost-effective. In addition, wireless sensors can send alerts when certain parameter thresholds have been crossed.

Important Points

  • Increase in photosynthesis results in increased growth rates and biomass production.
  • If CO2 levels are monitored and adjusted plants have an earlier maturity and more crops can be harvested annually. The decrease in time to maturity can help in saving heat and fertilization costs.
  • Never allow CO2 to exceed plant requirements. Have an alert system when CO2 level reaches 2 000 ppm and below 200 ppm;
  • Always monitor the CO2 levels through sensors and adjust to the required level.
  • In addition monitor growing condition like

Background information for this article was provided by Aranet. For more information visit

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