According to the researchers, the process is simple and inexpensive, and could be widely deployed in arid regions
Researchers at the Massachusetts Institute of Technology (MIT) have come up with a process for protecting seeds from the stress of water shortage during their crucial germination phase, and even providing the plants with extra nutrition at the same time.
The process, undergoing continued tests in collaboration with researchers in Morocco, is simple and inexpensive, and could be widely deployed in arid regions, the researchers say. The findings are reported this week in the journal Nature Food, in a paper by MIT professor of civil and environmental engineering Benedetto Marelli, MIT doctoral student Augustine Zvinavashe ’16, and eight others at MIT and at the King Mohammed VI Polytechnic University in Morocco.
The two-layer coating the team developed is a direct outgrowth of years of research by Marelli and his collaborators in developing seed coatings to confer various benefits.
The new coating, taking inspiration from natural coatings that occur on some seeds such as chia and basil, is engineered to protect the seeds from drying out. It provides a gel-like coating that tenaciously holds onto any moisture that comes along, and envelops the seed with it.
A second, inner layer of the coating contains preserved microorganisms called rhizobacteria, and some nutrients to help them grow. When exposed to soil and water, the microbes will fix nitrogen into the soil, providing the growing seedling with nutritious fertiliser to help it along.
Early tests using soil from Moroccan test farms have shown encouraging results, the researchers say, and now field tests of the seeds are underway.
The materials needed for the coatings are readily available and often used in the food industry already, Marelli says. The materials are also fully biodegradable, and some of the compounds themselves can actually be derived from food waste, enabling the eventual possibility of closed-loop systems that continuously recycle their own waste.
Although initial tests using common beans have shown promising results by a variety of measures, including root mass, stem height, chlorophyll content, and other metrics, the team has not yet cultivated a full crop from seeds with the new coating all the way through to harvest, which will be the ultimate test of its value.
