“How much CO2 do greenhouses use?” If you’ve asked yourself this question a couple of times, then you must be one of the countless others who are planning on speeding up the growth and development of their polytunnel plants.
In case you’re not aware, CO2 or carbon dioxide is an essential component of photosynthesis. Photosynthesis refers to the chemical process that converts light energy into sugars that will serve as food for your plants.
It’s important to note that each time you harvest your crops in the UK, carbon dioxide taken out of your greenhouse. For this reason, it’s best to keep the carbon dioxide levels constantly replenished to keep the other polytunnel plants healthy.
CO2 Usage of Greenhouses
Typically, CO2 concentrations at night are higher than daytime, as plants usually utilise CO2 during the day through photosynthesis. However, the rate of consumption will depend on the crop variety, light intensity, temperature, and crop development stage. However, in general, the CO2 consumption of plants may range from 0.12–0.24 kg/hr/100 m2.
Essentially, indoor farms or greenhouses should have carbon dioxide levels between 800 ppm to 1200 ppm. Other farmers use up to 1500 ppm in their greenhouses, but there’s usually a law of diminishing returns once they go beyond that point. For this reason, many farmers choose not to go beyond 1200 ppm in their internal levels of CO2.
Enough CO2 is essential for the growth of the plants. Growers need to maintain enough carbon dioxide levels in their greenhouses to ensure that their crops’ growth won’t be disrupted. In general, plants won’t grow in an environment where the carbon dioxide levels are less than 250 ppm.
Ways to Supplement Carbon Dioxide in Your Greenhouse
Thanks to the wide surface area of the environment outside a greenhouse, plants can still manage to survive even without CO2 supplementation. However, it’s an entirely different story if you grow your plants inside a hobby greenhouse. The limited space will cause them to utilise the ambient carbon dioxide available in the enclosed area until the CO2 levels significantly reduce.
Carbon dioxide (CO2) supplementation is the term used to refer to the process of adding additional carbon dioxide inside polytunnels to increase the CO2 concentrations and improve the plant’s photosynthesising abilities. Studies show that an 800 ppm to 1000 ppm increase in the levels of CO2 inside a polytunnel leads to a 40% to 100% increase in yield.
If your sensors detect a drop below the recommended CO2 concentrations (150 ppm to anywhere below 800 ppm), here are some ways to supplement carbon dioxide in your greenhouse:
Method #1: Burning fuels (i.e. propane and natural gas)
One of the most common methods of CO2 supplementation is the combustion of natural gasses and propane. These gasses do not contain any harmful or dangerous amounts of components, which is why it’s the recommended way to supplement carbon dioxide in your greenhouse. Burning 1 m3 of natural gas produces at least 1.8kg of carbon dioxide that the plants can utilise.
Method #2. Compressed CO2 tanks
Another standard method of supplementing CO2 is by using compressed CO2 tanks. These tanks released through a vaporiser, and the CO2 distributed throughout the polytunnel through the holes in the PVC pipes. In more miniature greenhouses, however, the CO2 may be released directly from the tank.
Method #3. Decomposition method
The decomposition method is another effective method that helps increase yourpolytunnelCO2 levels. In this method, all you have to do is place organic wastes such as food scraps in plastic containers, and over time the microbial action that will take place within the substrate will produce CO2, which the plants can then take advantage of. The downside to this method is that the growers may have to deal with the odour, and it would require a large amount of substrate to supply the right amount of carbon dioxide your plants need.
Advantages of Growing Plants Inside a Hobby Greenhouse
Hobby greenhouses are among the ideal places to grow your plants. With one, you’ll better control the environmental conditions and ensure that your crops are grown in the right conditions. Right conditions, in turn, promises greater plant yield, increased harvests, and more.
Aside from that, here are the other benefits of growing plants inside a hobby greenhouse:
You can grow any plants
One of the most significant advantages of having a hobby polytunnels that you can grow just about any plant you want. If you’re going to grow a cold-season plant during the summer or a warm-season in the UK plant during the colder days, you can do so with a greenhouse. Greenhouse planting is essential because you’ll control the temperature inside the hobby greenhouse, thus, allowing your plants to survive and thrive despite the cold or warm season.
With a hobby greenhouse, you can provide the optimal climate conditions needed by your plants. You may even perform carbon dioxide supplementation, which will significantly increase the yield of your crops.
Protection from harsh weather conditions and predators
Hobby greenhouses protect your plants from extreme weather conditions. Be it strong winds or heavy rains, and you can rest easy knowing that the enclosure will keep your crops safe and free from damage. Besides that, hobby greenhouses also offer protection from birds, deer, squirrels, and other animals that might feed on your plants.
Summary: How Much CO2 Do Greenhouses Use?
Plants need a sufficient supply of carbon dioxide to make sure that they strive and grow well. To ensure that your plants won’t run out of CO2 to use, you have to make sure that the ambient carbon dioxide inside your polytunnel reaches at least 800 ppm to 1200 ppm.
If needed, supplement CO2 by burning fuels or using compressed CO2 tanks in your greenhouse. Higher levels of carbon dioxide in the environment increase crop yield by 40% to 100%.
“How much CO2 do greenhouses use?” The next time someone asks you this question, let them know that you can’t determine the exact amount because the number may vary depending on several factors, including the type of crop, light intensity, and the plant’s stage of development.