How can aeroponics improve productivity in greenhouses?
How can aeroponics increase productivity in greenhouses?
Greenhouses and polytunnels neatly bridge the gap between outdoor and indoor farming. The levels of control can vary greatly depending on the system: some use LED lights to compliment natural sunlight, deliver nutrients as part of the irrigation process, and sustain warm enough temperatures to grow crops out of season. All these conditions will go some way to protect growers and their produce from the ever-increasing threat of climate change.
Harvesting crops throughout the year with the lowered threat of pests, disease or extreme weather can make greenhouses vastly more productive than land outdoors. With retailers increasingly turning to CEA to help them achieve their sustainability goals, it’s no wonder the commercial greenhouse market size is predicted to grow to $49.26 billion by 2027.
But the reality is that commercial greenhouse growers still see threats to their productivity, especially with extortionate energy costs eating up a healthy chunk of profits. A year on from the start of the Russian war on Ukraine, and parliamentary figures are still working at odds with potential solutions to the energy crisis, leaving individuals and businesses alike struggling to keep afloat. Due to the breadth and scale of their operation, greenhouse growers in particular face a unique set of challenges - and can see their productivity being capped.
If greenhouse growers are to see an improvement in profits, their operational efficiency and productivity must be improved.
The big picture
Productivity comes down to one core aspect: crop yields. Powering lights alone can make up to 30% of a greenhouses outgoing costs, with labour and operational costs that come with producing and distributing crops at scale eating into potential profits too. Simply turning the lighting off and relying on natural sunlight is one option - but this will only lead to a further drop in productivity, especially in the winter months. If a greenhouse facility is already automated, and is running with minimal staff and a mix of cost-effective energy sources, increasing crop yields is going to be the most effective way to improve profitability.
There are guaranteed ways to make greenhouses more efficient, and although these can make greenhouses more resilient or streamlined, increasing productivity is going to be the leading factor in growing revenue. The three main areas that greenhouses have to control and improve are lighting, temperature and irrigation.
Temperature control
Low control
Making changes to ambient environments in greenhouses is a particular struggle. In hectare-scale facilities, greenhouse growers will typically find pockets of inconsistencies in temperature, CO², oxygen, humidity and airflow rates. Heating and cooling vast areas is costly, so they could find internal temperatures to be at the mercy of outdoor factors a lot more than vertical farming set-ups.
Automation has also vastly improved the efficiency of greenhouses, which is why it is so widely adopted in large-scale facilities. Growers can accurately automate transportation, nutrients and lighting, but greenhouse environmental control has not yet benefited from the same level of optimisation. You can transport crops with ease, but the ambient temperatures and pockets of temperature inconsistencies in hectare-scale facilities make this element a particular challenge.
Lighting
Medium control
Greenhouse growers have a particular advantage over vertical farming set-ups in this area. Using a combination of sunlight and UV LEDs will greatly reduce overall lighting costs while giving plants all the energy they need to flourish. The LED grow light industry is rapidly changing, and has benefited from an increased amount of research in recent years.
With advancements accelerating, greenhouse growers are now encouraged to choose up-to-date LED lighting over fluorescent or high-pressure sodium lights, use equipment that is no more than five years old, and consider the right spectrums for their crops.
Ultimately these updates will allow greater control over costs, growth performance and overall plant health, but are unlikely to greatly increase the overall productivity of greenhouses significantly.
Irrigation
High control
Irrigation is the way in which growers water their crops. Greenhouses typically use hydroponics feeding water and nutrients directly to the roots, trickle irrigation in the soil, or overhead irrigation lines to crops planted in the soil, and in recent years has not seen as much innovation or development when compared to the lighting industry, for example. Irrigation holds untapped potential, and for greenhouse growers they can not only have vastly increased control, but can significantly increase crop production.
Aeroponics is an irrigation method which is not currently used at scale, but could be the key for many greenhouse growers to greatly improve productivity. With aeroponics, plant roots are irrigated with a nutrient-rich mist. Thousands of water droplets are dispersed using ultrasonic sound waves, irrigating a perfect blend of water, nutrients and oxygen onto plant roots. This greater access to oxygen means that plants are healthier, happier and most importantly grow faster. Original trials in our aeroponic container farms resulted in exciting growth rates increases of between 20-200% compared to hydroponic containers.
Using ultrasonics also removes the need for nozzles, a common method used throughout the aeroponic industry. Using nozzles to create mist adds significant complexity and maintenance issues, making it unsuitable for large-scale commercial growers. Although nozzle-free aeroponics is not yet widely available, LettUs Grow are working to make that a reality.
LettUs Grow are currently working with Crop Health and Protection and Stockbridge Technology Centre to bring Aeroponic Rolling Benches™ to the large-scale greenhouse market, allowing commercial growers to unlock and accelerate their productivity potential. Having focused on greenhouse trials with academic partners, we've observed consistent growth rate improvements of up to 20% in leafy greens and herbs.
Ultimately, there are many factors to consider when looking to improve productivity, and it’s likely a combination of all of the above will be considered to make a real impact in both efficiency and productivity.
LettUs Grow is dedicated to working in collaboration with world-leading greenhouse growers to bring ultrasonic aeroponics to the hectare-scale growing industry, and open doors to new and innovative irrigation technologies. If you’d like to find out how Aeroponic Rolling Benches could work in your greenhouse, make sure to sign-up for the mailing list here.
