Skip to Content

Silky seeds

A coating made from silk, bacteria, and nutrients could help crops thrive where nothing grows.
February 26, 2020
sprouts and seeds in silky containers
sprouts and seeds in silky containersCourtesy Image

Coating seeds with specially treated silk could make it possible to grow crops in otherwise unproductive soils, according to new research at MIT.

The silk, which protects the seeds from soil that would normally be too salty, also contains a kind of bacteria that naturally produce a nitrogen fertilizer. Lab tests have shown that the seeds grow successfully in these salty conditions.

The findings grew out of research by Benedetto Marelli, a professor of civil and environmental engineering, on using silk coatings to extend the shelf life of seeds used as food crops. During this work, he “stumbled on biofertilizers that can be used to increase the amount of nutrients in the soil,” he says. Such fertilizers use microbes that convert nitrogen from the air into a form plants can readily take up. They avoid the drawbacks of conventional nitrogen fertilizers, which he says may degrade soil quality and are very energy intensive to produce.

Although nitrogen-fixing bacteria occur naturally in soils around the world, they are very hard to preserve outside their native environment. But Marelli and his team found that mixing them with silk derived from silkworm cocoons (like those seen here) and a type of sugar did the trick. In practice, the treated silk could be simple to apply to seeds by either dipping or spray coating, they say. Legumes such as beans and chickpeas have been the focus of the research so far, but it may be possible to adapt the technique to other crops.

The researchers are now working on coatings that could also make seeds more resistant to drought. They plan outdoor tests in Morocco this year.

Keep Reading

Most Popular

10 Breakthrough Technologies 2024

Every year, we look for promising technologies poised to have a real impact on the world. Here are the advances that we think matter most right now.

Scientists are finding signals of long covid in blood. They could lead to new treatments.

Faults in a certain part of the immune system might be at the root of some long covid cases, new research suggests.

AI for everything: 10 Breakthrough Technologies 2024

Generative AI tools like ChatGPT reached mass adoption in record time, and reset the course of an entire industry.

What’s next for AI in 2024

Our writers look at the four hot trends to watch out for this year

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.