"Airflow is often improperly managed in microgreens farms. Many farms use small fans that blow directly onto the crops throughout their entire lifecycle. However, this approach can lead to uneven moisture levels, especially during watering. Areas exposed to constant airflow dry out faster than those without consistent ventilation, which can exacerbate moisture-related issues. As a result, I believe the use of these fans is excessive and counterproductive," says Jonah Krochmalnek, Founder and CEO of Microgreens Consulting.
Whilst diving into the key environmental controls of microgreens farming, Jonah continues explaining that constant air distribution can lead to inconsistency in crop development. "To maintain uniform temperature and reduce the risk of mold formation, airflow should be directed in a controlled pattern. This ensures a more consistent environment across the entire growing area," he advises.
Humidity control
"Maintaining stable humidity levels is crucial for minimizing pathogen risks in microgreens farming," says Jonah Krochmalnek, Founder and CEO of Microgreens Consulting. "This can be achieved by ensuring consistent moisture levels in the substrate. Overly saturated microgreens struggle to transpire excess moisture, which can significantly hinder their growth."
A balanced humidity level is essential, not too low, and not too high. Jonah recommends maintaining humidity levels between 40-60%. "If the humidity exceeds 70%, you'll likely see slower growth and an increased risk of diseases," he warns. To manage humidity and climate conditions within the farm, Jonah suggests utilizing air conditioning and dehumidification systems. "It's better to oversize the air-conditioning system by 10-20% to ensure it operates below maximum capacity, which will help extend its lifespan."
Jonah also highlights the importance of understanding the relationship between temperature and humidity. "As you get closer to the ceiling, the air is warmer and can hold more moisture, while colder air is denser and holds less moisture," he explains. "Relative humidity isn't the same as total humidity, so positioning dehumidifiers near the ceiling can make them more effective at extracting moisture from the air."
Temperature management
Proper air circulation is key to maintaining an even temperature distribution in your grow room. Jonah notes, "Having fans that circulate air vertically allows for more consistent air distribution. In larger facilities, I recommend ducting to ensure a consistent climate throughout the grow room, with even airflow from bottom to top."
Temperature significantly influences the growth rate of your plants. Jonah explains, "At 60°F (15°C), plants will grow slower than at 70°F or 80°F. Adding a heater to your grow room can help achieve the optimal temperature for faster growth." Vice versa, if the cultivation space becomes too warm, incorporating an HVAC system is advisable. "In the long run, an HVAC system will pay off," Jonah notes. "To optimize crop growth speed, maintaining a temperature of 80°F is ideal."
CO2 Injection
While CO2 supplementation is not typically critical for microgreens, it becomes more relevant when cultivating other crops in vertical farms. Jonah points out, "If you're dehumidifying your grow room, it's more important to monitor CO2 levels, as fresh air intake may be limited. In our microgreens farm, we never added CO2, but for crops like lettuce, it can be necessary to speed up growth."
CO2 levels generally range between 400 to 450 ppm in microgreens farming, but they can drop into the 300s, potentially limiting crop growth. "It all comes down to the weakest links," Jonah explains. "When everything else in your growing setup is perfected, CO2 can become a limiting factor if it drops too low, especially for crops like lettuce."
For more information:
Microgreens Consulting
Jonah Krochmalnek, Founder and CEO
[email protected]
www.microgreensconsulting.com