Successful cultivation of plants using simulated lunar soil as a step toward realizing space farming
Obayashi Corporation and TOWING Co., Ltd. (*1) have conducted field testing in crop cultivation using simulated lunar soil and organic fertilizers, and have succeeded in cultivating crops.
In recent years, initiatives are gaining momentum toward expanding use of space development. With regard to lunar development, Japan has announced intent to join the international space exploration project, the Artemis program, proposed by the U.S., and as part of the program by several government agencies and ministries, the Strategic Program for Accelerating Research, Development and Utilization of Space Technology (Stardust Program), various initiatives are being taken toward lunar development.
Materials such as water and food are essential for manned activities on the Moon, which will initially be transported from the Earth. However, to continue activities in the long term, utilization of resources on the Moon and recycling-oriented materials are thought to be needed.
Also, by conducting plant cultivation in facilities such as plant factories using artificial light on the Moon, material transport from the Earth can be significantly reduced and improvement in QOL (quality of life) during human stay can be realized. However, it is believed that transport costs will become a barrier if the entire system for plant cultivation were to be transported from the Earth.
Thus, Obayashi and TOWING have collaborated to develop a technology to fertilize lunar soil to enable plant cultivation. Obayashi Corporation and JAXA along with others are working together for technical development to use lunar soil as construction materials using microwave or laser, and TOWING possesses technology to design inorganic porous material (*2). Utilizing technology for artificial soil formation (*3) developed by the National Agriculture and Food Research Organization, TOWING also possesses know-how in making it possible to cultivate artificial soil using organic fertilizers. This latest plant cultivation experiment combines all such knowledge and experience to design and manufacture porous material from simulated lunar soil, and to form soil for use in cultivating Japanese mustard spinach.
Features of this technology are described below.
Artificial soil from waste material generated in space that can be used as organic fertilizer
If hydroponics and nutriculture were to be used to cultivate plants in space, chemical fertilizers must either be transported from the Earth or manufactured in space. As the technology developed uses organic material as fertilizer, organic waste material generated by humans such as feces, urine, and food waste can be recycled. It does not require manufacture of chemical fertilizers, and can produce plants highly efficiently and realize sustainable agriculture.
Production of porous material with a high recovery rate
Porous material as soil is manufactured by heat treating and firing simulated lunar soil with microwave energy. Uneven temperature conditions during the process may cause a decreased ratio (recovery rate) of porous material suitable for plant cultivation. As energy is a precious resource in space, it is necessary to raise the recovery rate.
The technology developed enables even heating, which allows almost all manufactured products to become suitable for plant cultivation, for effective usage of energy.
Cultivating various plant species and recreating tastes
For people to live as humans in closed space with low gravity, their diet becomes an important factor.
The technology developed allows for conditions similar to cultivation in soil, such as by using microorganisms stemming from soil, which makes it possible to produce root vegetables and large crops. Going forward, we will recreate a variety of tastes that appeal to the senses of the human body, such as firmness of leaves.
By putting plant cultivation technology on the Moon into practical use, Obayashi and TOWING will realize increased QOL in space activities and contribute to sustainable space development for the future.
- *1 TOWING Co., Ltd.
A venture corporation started by Nagoya University aiming for development of agriculture on the Earth and realization of space agriculture, leveraging technology enabling artificial soil cultivation using organic fertilizers
- *2 Porous material
Materials containing pores (air gaps) within, such as activated carbon, zeolite, and pumice stones, mainly used in catalyst supports and adsorbents
- *3 Soil formation
Soil microorganisms are fixed into sand to enable it to decompose organic fertilizers into inorganic matter able to be absorbed by plants