Agriculture: Bioinspired seed carrier improves on nature

A new biodegradable seed carrier design inspired by the self-drilling behaviour of Erodium seeds is described in a paper in Nature. The seed carrier has a higher implantation success rate than that of Erodium seeds. This technology may improve the effectiveness of aerial seeding to address agricultural and environmental stresses in degraded regions.

Aerial seeding is a crucial way to cover large and otherwise inaccessible areas, and can facilitate post-fire reforestation or wildland restoration. However, when a seed lies on the surface, it can be damaged by weather conditions or eaten by wildlife, resulting in low germination rates. Seeds of various grass species can self-bury, an ability that would be advantageous if applied to different seed types.

Lining Yao and co-authors designed a wood-based biodegradable seed carrier that mimics seeds of Erodium, a genus of plants with seeds that unwind coiled tails to act as a drill to plant into the ground. The seed carrier has three coiled tails attached that unwind when moistened and can carry seeds as large as those of whitebark pine trees, which are about 11 mm long and weigh about 72 mg. Increasing the number of unwinding tails ensures the drill bit is better angled to the surface for burrowing. The seed carriers had an 80% success rate of getting seeds into the ground on flat land (the most challenging terrain), reducing the risk of them blowing away or being eaten by animals. Under the same terrain conditions, the natural Erodium seed’s success rate was 0%. The carriers could also be used to deploy fertilizers or other materials (such as sensors) that could be beneficial for agricultural and conservation applications, the authors conclude.