Carbon dioxide (CO2) is an essential component of photosynthesis. The whole process of photosynthesis is dependent on using light energy to convert CO2 and water into sugars that the plants use to grow. A main goal of greenhouse production is to efficiently promote the photosynthesis process to economically maximize crop yield. For this to happen the growing environment needs to supply the plants with the perfect amount of photosynthesis ingredients, otherwise production will be slow or nonexistent. The one extremely important ingredient that is often neglected in the greenhouse is CO2. Studies have proven that up to a point (around 1400-1500 parts per million (ppm)) increasing the amount of CO2 promotes flowering, higher fruit yields, reduced bud abortion in roses, improved stem strength and flower size. Below is a video of Dr. Nate Storey from Bright Agrotech explaining the importance of supplemental CO2 for better plant production:
Dr. Storey explains that carbon is one of the most important things for plant structure and growth. Being a mostly closed environment, greenhouses can end up with a very low amount of CO2 if it is not being replenished. This is especially common during the winter, as fewer air exchanges are happen and the greenhouse is mostly sealed to conserve heat. As plants absorb the CO2 in the greenhouse it decreases the amount in the air. This becomes a problem, because once the CO2 level gets below 300 ppm the plants essentially stop growing. No matter how much light, nutrients, or environmental control you have in your greenhouse the plants will not grow. At this point your variable costs (heating/cooling, electricity, nutrients, etc.) will continue to rise even though your plants are not growing.
Supplemental CO2 is fairly cheap and can have a substantial impact on your crop. First you need to check your CO2 levels. This can be done with a small handheld device or by simply checking your main control system. Look for elevated levels, and aim to be running between 800-1200 ppm. According to Dr. Storey 1200 ppm will boost most plants to grow effortlessly, meaning that they will grow more efficiently with less water. Also, if you are having problems with transpiration and controlling your humidity, introducing more CO2 can potentially be your fix.
In the video above Dr. Storey mentions Able.Ag’s CO2 Calculator for estimating how much supplemental CO2 your grow will need, and how much it will cost. Below is a screen shot of the Able.Ag form:
I love hearing about simple and affordable upgrades that can help boost yields! I highly suggest researching into your greenhouse’s CO2 level to see if you can can benefit from supplemental CO2. Do you have any experience with this topic? How are your CO2 levels? What levels do you operate at? Please leave your thoughts in the comment section below.