Growing rice in a coal-dark cellar in the city, or growing tomatoes and lettuce in a spaceship or on Mars. According to US researchers, a new technique is possible. It is even more efficient than conventional agriculture. “Less land is needed.”
The method, published last week in the scientific journal Nature food, skips the step of photosynthesis in crops. This is the process by which plants use sunlight to convert CO2 and turn water into building materials they need to grow. They do not do this very efficiently: often only about one percent of the available energy is converted from sunlight into biomass.
This is why scientists around the world are considering the question of how photosynthesis can be ‘stepped up’. Higher efficiency results in a higher yield of crops, so less farmland is needed for the same amount of food. While some researchers focus on improving the plants through genetic modification (with only limited production gains at present), the US research team is choosing an alternative route that does not require sunlight.
Doctor Dog would like to sniff for you
Instead, electricity is used to produce CO2 and converting water – through a process called electrolysis – into acetate, the main constituent of vinegar. Like the sugar produced by photosynthesis, organisms can use these things as an energy source to grow.
Experiments show that this is done more efficiently than in ‘traditional’ agriculture. When the power comes from solar panels, a larger part of the energy is converted from sunlight into biomass.
For example, it turned out that yeasts normally fed sugar from maize grew 18 times more efficiently using the ‘acetate method’. In addition, the team found that a large number of crops, including tomatoes, lettuce, rice and peas, are suitable for growing in a dark room via acetate.
CO2 filter the air out
A beautiful and original study, says Huub de Groot, professor of biochemistry at Leiden University and not involved in the research. ‘It was already known that organisms can grow on acetate and also that these things can be produced via electrolysis. Still, it is an innovative idea to combine these two steps in this way. With these results, a whole new field can be explored. ‘
Although De Groot believes that the process is less efficient than the researchers make it seem. ‘Plants themselves filter CO2 from the air, while here it is supplied in concentrated form. The step before, removal and concentration of CO from the air2, takes energy. They do not seem to have expected that now. There are also a number of sources of concentrated CO2 available, for example, from the industry that you can use for this. ‘
The research group sees a number of new possibilities by ‘freeing’ agriculture from complete dependence on sunlight. “Using this technique may represent a paradigm shift in the way we feed humans,” Robert Jinkerson, a chemist at the University of California, said in a news release. ‘Due to the increased efficiency, less land is needed, which reduces the impact of agriculture on nature.’
Fresh tomatoes on Mars
Because crops grow in a controlled environment, they are also less vulnerable to the effects of climate change, such as droughts and floods. And for the purchase of suitable agricultural land, because with the method, food can also be grown in less common places, such as in (dark) buildings in cities.
Which, incidentally, could also be useful for future space travelers, the researchers note. The limited space required and the independence of sunlight mean that the technology could potentially also yield fresh tomatoes or lettuce in a spaceship or on Mars. “While the increased efficiency helps feed more crew members with less input,” Jinkerson said.
An additional advantage is that known crops can be produced with this method without many adjustments, notes De Groot. The salad or rice head on the plate remains the same. One does not directly intervene in the organism’s DNA, and the crops still grow in a natural way. It is very different from, for example, cultured meat. ‘