TORONTO — Climate change experts have been warning that, as the global temperature continues to rise, extreme weather events such as droughts, storms and floods will become more frequent and severe.
In the face of a global climate crisis which will put strain on the agricultural sector and potentially cause food shortages, U.S. researchers at MIT have begun engineering seeds to resist drought.
The study, published in the journal Nature Food this week, is a collaboration between MIT and researchers in Morocco at the King Mohammed VI Polytechnic University, and examines a new seed-coating process that enables the seed to retain any available water, possibly facilitating agriculture on arid lands, according to a release.
The research process and tests are ongoing, but is simple and inexpensive and could be widely deployed in hard-hit drought regions, according to the study.
The two-layer coating developed to help seeds retain water builds off of previous work at MIT that enabled seeds to resist high salinity in the soil, but this version specifically tackles the challenges of water shortages.
“We wanted to make a coating that is specific to tackling drought,” said study author and MIT professor Benedetto Marelli in the release. “Because there is clear evidence that climate change is going to impact the basin of the Mediterranean area,” he says, “we need to develop new technologies that can help to mitigate these changes in the climate patterns that are going to make less water available to agriculture.”
The new coating created by researchers was inspired by the natural coating found on some seeds like chia and basil that is naturally engineered to protect the seeds from drying out. The gel-like coating allows the seed to hold on to any moisture that comes along and envelops the seed with it.
A second, inner layer of the seed coating contained preserved microorganisms called rhizobacteria and some nutrients to help them grow, which when exposed to water and soil the microbes will affix nitrogen into the soil providing the seed with fertilizer to help it along.
“Our idea was to provide multiple functions to the seed coating, not only targeting this ‘water jacket’ but also targeting the rhizobacteria,” Marelli said. “This is the real added value to our seed coating, because these are self-replicating microorganisms that can fix nitrogen for the plants, so they can decrease the amount of nitrogen-based fertilizers that are provided, and enrich the soil.”
The study says early tests using soil from Moroccan farms have shown encouraging results and now field tests are underway. Researchers say the coatings are simple enough they could be applied at the local level, even in remote locations in the developing world.
“That’s one of the things we were thinking about while we were designing this,” said study author Augustine Zvinavashe. “The first layer you could dip coat, and then the second layer, you can spray it on, these are very simple processes that farmers could do on their own.”
The materials used for the seed coatings are readily available and are often used in the food industry already, the study says, with the added benefit that the coating materials are fully biodegradable and some compounds can be derived from food waste – which points to a possible future recycling system in areas that the seed is being used.
Researchers hope that, even though the process of coating the seeds adds a small cost, the savings incurred by reducing water and fertilizer inputs may balance it out, but more research is needed and the team has not cultivated a full crop of coated seeds all the way through to harvest yet.
Marelli said the system is “simple” enough that it can be applied to any kind of seed, and that the team “can design the seed coating to respond to different climate patterns,” laying the groundwork to be able to tailor the seed coatings to predicted rainfall of a particular growing season.