The use of plasma in sustainable farming
Alaia Lafleur discusses what plasma is and the potential uses for sustainable farming in the future with the ever increasing human population.
Scientific research shows nonthermal plasma (also called cold plasma) can aid in sustainable agriculture. Studies are promising, showing great potential for seed sterilization, plant growth, food preservation, and aid in soil contamination. According to the IPCC’s Special Report on Climate Change and Land (2019) agriculture directly produces up to 8.5% of global greenhouse gas emissions. This does not include deforestation to yield more land for food production, but cold plasma could radically change how farmers and consumers impact the world around us.
Agriculture directly produces up to 8.5% of global greenhouse gas emissions.
But, what is plasma again?
When first I told my flatmate about this article they were vaguely unsettled by the idea of a bunch of farmers cheerfully sprinkling human blood on their seasonal crops. An idea that is not as ridiculous as it sounds: a common fertilizer, blood meal, is essentially made up of dried animal blood. But no, I’m referring to plasma, the “fourth state of matter”. It is a state after gas becomes superheated or electrically energized to the point electrons are severed from atoms. It is a large component of the sun, helps create the aurora borealis display and forms more than 99 percent of our visible universe. Humans already use cold plasma, created under low-pressure conditions, to create electronic chips, rocket propulsion, and those fun plasma lamps largely appreciated for their lighting tricks !
But in more recent decades increasing experiments have demonstrated new uses. These include mixing irrigation water with plasma, blasting crops with plasma “jets”, and even balancing seeds on a plasma lamp. Biochemist Alexander Volkov balanced 20 seeds on a plasma lamp for one minute each and then incubated them in water. After two days the first little root to pop out of the seedlings measured almost a centimetre longer than in untreated seeds. Nitrogen-rich plasma can be used to increase seed germination rates and plant growth. It is effectively a fertilizer and incredibly valuable for environmental health and sustainable farming. Many commercial fertilizers contain ammonia, the production of which is responsible for about 1.8 percent of global carbon dioxide emissions. If 100 percent reduction of emissions is to be attained by 2050 as per the Climate Change Act, the creation of a “green” fertilizer is an absolute requirement.
Many commercial fertilizers contain ammonia, the production of which is responsible for about 1.8 percent of global carbon dioxide emissions.
Another way in which cold plasma can aid farming is through its inactivation of microbial pathogens like viruses, bacteria, and fungi. In 2017 researchers at the American Society for Microbiology reported that they were able to eliminate 99 percent of norovirus particles from romaine lettuce leaves and stainless steel surfaces after blasting them with cold plasma for five minutes.
Plant pathologist Brendan Niemira states: “Even in this very, very early stage of research that we’re at with plasma, which has really only come into its own in the last 10 to 15 years, we’re seeing very promising data,”. But the next question is “Can we make it work in a field environment [to] deliver an advantage that can be integrated into grow systems in the future?” The next step is optimizing cold plasma for expansive lands and large-scale harvests and finding out whether it can work as well in this environment or in diverse terrains.
