A scientific research team led by the University of Texas at Austin recently announced that they have successfully grown and harvested chickpeas in "lunar soil" that simulates the material on the moon's surface, providing an important experimental basis for future astronauts to grow fresh food locally on the moon. The relevant results were published in the journal "Scientific Reports" on March 5.
As the National Aeronautics and Space Administration (NASA) prepares for the Artemis II mission and humans return to the lunar surface, "what to eat" during the long-term stay has become a real and urgent issue. The latest research from a team at the University of Texas gives a rather down-to-earth candidate answer: chickpeas. Researchers have successfully grown and harvested chickpeas in specially prepared simulated "lunar soil". This is also the first time that this crop has been completely grown in a simulated lunar soil environment.
Sara Santos, a postdoctoral researcher at the Institute of Geophysics (UTIG) at the University of Texas Jackson School of Geosciences and the main leader of this study, said that the core goal of the work is to clarify the feasibility of growing crops on the moon. She pointed out that the loose material covering the moon is scientifically called "lunar soil", which is completely different from the soil on the earth. It has neither organic matter nor the microbial community that plants need to survive. It also contains heavy metals that may inhibit plant growth, but it also contains mineral elements needed for crops.
To get as close to the real environment as possible, the team used simulated lunar soil prepared by Exolith Labs. The chemical and physical properties of this material were based on lunar samples brought back by the Apollo missions. The researchers then added "vermicompost" to the simulated lunar soil - a highly nutrient material produced by red worms decomposing organic waste. It is rich in key nutrients and complex microbial communities and can significantly improve plant growth conditions. It is envisaged that in real manned missions in the future, astronauts can convert organic waste such as food residues, cotton clothing and even some daily hygiene products into similar compost, which can be used to improve the lunar soil.
In terms of crop selection, the team chose the "Myles" variety of chickpea because it has a compact plant type, strong stress resistance, and is suitable for planting in mission environments with highly limited space and resources. In order to solve the problem of loose structure and poor water retention capacity of the simulated lunar soil, the researchers also developed an irrigation system based on cotton water-conducting cores to accurately transport water to the chickpea root zone to ensure that root moisture supply is maintained under extreme substrate conditions.
Notably, the scientists deliberately coated chickpea seeds with arbuscular mycorrhizal fungi before sowing. Such fungi can establish a symbiotic relationship with plant roots. On the one hand, they help plants absorb nutrients more effectively. On the other hand, they reduce the proportion of heavy metals absorbed by plants from the soil, thereby alleviating the pressure of "toxic environments." The Santos team conducted planting tests after mixing different mixtures of simulated lunar soil and vermicompost. The results showed that in substrates with lunar soil accounting for up to 75%, chickpeas can still grow and harvest normally. However, when the lunar soil ratio continues to increase, the plants begin to weaken significantly and even die early. Even under highly stressful conditions, fungus-treated plants survived significantly longer than untreated plants, highlighting the key role of mycorrhizal fungi in this extreme agricultural system.
The researchers also found that these fungi can not only successfully colonize the simulated lunar soil environment, but also maintain it for a long time, which means that in future lunar planting systems, fungi may only need to be introduced for the first time to continue to function. But while a successful harvest is an important milestone, whether chickpeas are safe to eat still needs further verification. Jessica Atkin, the first author of the paper and a doctoral student in the Department of Soil and Crop Science at Texas A&M University, said that the next step will be to conduct a systematic analysis of the harvested chickpeas to evaluate whether they are enriched with potentially harmful metals and to determine their nutritional composition. She asked a series of questions about the potential applications: Are these chickpeas suitable for astronaut food? Are the nutrients adequate? If it is not safe enough at the beginning, how many generations of breeding and environmental regulation will it take to reach the standard?
The research was initially launched largely with self-funding by Santos and Atkin, and was continued and expanded with funding from NASA's FINESST project. As human deep space exploration missions gradually move from short-term experiments to long-term stays, the exploration of "in situ agriculture" in extreme environments is shifting from science fiction concepts to real laboratories, and the chickpeas successfully planted in "lunar soil" are the latest sample in this process.