Plasma Agriculture Makes Strides Towards Super-Seeding Conventional Methods

Every once in a while, the sun unleashes powerful flares and coronal mass ejections which hurl plasma and energetic particles into space. On the infant Earth, this solar activity drove cascades of atmospheric chemical reactions that may have helped form the building blocks of life. More recently, scientists have discovered that applying plasma to seeds in a controlled way can trigger similar activity to make them more fast-growing and resilient. Researchers at Nagoya University and Kyushu University in Japan have compiled a comprehensive review of this new field — termed “Plasma Agriculture” — a potential sustainable solution to address global food shortage.

The word plasma brings to mind a hot, ionized inferno that makes up the fourth state of matter. But the plasma used here is different. By applying high electric voltage to air or any gas, electrons from a tiny fraction of its molecules get stripped off and gain very high energies. These electrons zipping around can effectively mimic the behavior of plasma even though the bulk of the gas remains at room temperature.

This low-temperature plasma, in turn, can be applied directly to seeds without burning them. Excessive use of chemicals and genetic modification of plants are a cause of concern for many people. In its place, plasma agriculture can offer similarly high crop yields without intrusion. 

“Low temperature plasma is an alternative to genetically modified crops”, said Kenji Ishikawa, professor at Nagoya University’s Center for Low-temperature Plasma Sciences. 

In a review published in the Journal of Advanced Research, Ishikawa and his collaborators at Kyushu University synthesize data from over 30 crop species and find that in more than two‑thirds of reported studies, well‑tuned plasma treatments boost seed vigor or yield, while the remaining cases show neutral or even negative effects when the dose is not properly controlled.

However, to ship this technology from the lab to the farm, a deeper understanding of the physical and biochemical processes through which low temperature plasma acts is necessary. For that reason, this review also summarizes the present state of knowledge of how and why plasma treatment works.