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Researchers have created a self-soiling “bionic” leaf that uses bacteria, sunlight, water, and air to fertilize its own crops.
The aim, according to the American Chemical Society (ACS), is to help spur another wave of agricultural innovation.
In the 1960s, increased use of fertilizer helped double rice and wheat production and induce the first “green revolution”—largely credited with averting a global food crisis.
Five decades and billions of people later, the challenge of feeding the world looms again.
“Providing food for everyone will require a multi-pronged approach, but experts generally agree that one of the tactics will have to involve boosting crop yields to avoid clearing even more land for farming,” the ACS said in a press announcement.
A team of Harvard scientists led by professor Daniel Nocera intend to do just that with their latest invention: the bionic leaf.
The augmented device—built upon Nocera’s original artificial leaf, which mimics the photosynthesis process of natural foliage—pairs a water-splitting catalyst with a bacteria that consumes hydrogen and pulls carbon dioxide out of the air to make liquid fuel.
Last year, Nocera’s team was able to successfully switch the plant’s poisonous reactant with a bacteria-friendly alloy.
“Getting to that point showed that you could have a renewable chemical synthesis platform,” Nocera said. “Now we are demonstrating the generality of it by having another type of bacteria take nitrogen out of the atmosphere to make fertilizer.”
The proof is in the radishes: Over a period of five crop cycles, the vegetables receiving bionic-leaf-derived fertilizer weighed 150 percent more than the control crops.
“When you have a large centralized process and a massive infrastructure, you can easily make and deliver fertilizer,” Nocera said. “But if I said that now you’ve got to do it in a village in India onsite with dirty water—forget it.
“Poorer countries in the emerging world don’t always have the resources to do this,” he continued. “We should be thinking of a distributed system because that’s where it’s really needed.”
The team presented their work Monday at the 253rd National Meeting and Exposition of the ACS.