Aerial seeding, a technique of sowing seeds by spraying them through aerial means like a drone or a plane, is crucial to cover large and inaccessible areas. However, once a seed lies on the surface, it can be damaged by weather conditions or eaten by wildlife, leading to very low germination rates. Now, a new seed carrier hopes to address this by giving a spinning boost to seeds.
Lining Yao, a researcher at Carnegie Mellon University, worked with a team of collaborators to create a biodegradable seed carrier called E-seed. E-seed was created from wood veneer and could be used for a variety of seeds or fertilizers and adapted to many different environments, explains Yao, whose family also works in farming.
“Seed burial has been studied for decades in terms of mechanics, physics and materials science, but until now, no one has created an engineering equivalent,” Yao said in a statement. “The seed carrier research has been particularly rewarding because of its potential social impact. We get excited about things that could have a beneficial effect on nature.”
Corking aerial seeding
Yao and her team designed a seed carrier that mimics seeds of Erodium, a gender of plants with seeds that are carried inside a thin wound stalk. The stalk unwinds and twists the seed into the soil, just like a corkscrew, when there’s rain or high humidity. This allows the seed to take root safely away from hungry birds in harsh environmental conditions.
The seed carrier has three coiled tails attached that unwind when moistened. They can carry seeds as large as those of whitebark pine trees (Pinus albicaulis), which as 11 millimeters long. While Erodium’s stalk has one unwinding tail, the researchers developed a three-tailed version for their seed carrier so it can work in a broader range of environments.
To manufacture it, the team first considered a wide range of possible materials, including hydrogels, paper, and other forms of processed cellulose. They finally went for veneers of white oak, a species of tree abundant at the university’s campus and widely used in furniture. As Erodium, veneers respond to moisture. “Seeds have a magic response to rain,” Yao said.
Then came the time to test it. The seed carriers had an 80% success rate of getting sees into the ground on flat land, the most challenging type of soil. Under the same conditions, the Erodium seed’s success rate was 0%. The carriers could also be used to deploy fertilizers or other materials that could be beneficial for agriculture, the researchers said.
However, the carriers were impacted by stormy conditions and still need more work to be used in remote locations affected by extreme weather, Samuel Mason and Naomi Nakayama, both from Imperial College London, who were not involved in the research wrote in a comment piece alongside the study. “They need to be refined if it’s to be scaled up,” they added.
The study was published in the journal Nature.