A joint research team from Hosei University and the University of Tokyo has successfully grown edamame in an artificial-light plant factory for the first time, producing stable, high-quality yields using hydroponic cultivation.

The findings, published in Scientific Reports (Volume 15), demonstrate that the nutrient film technique (NFT) can outperform conventional field farming in both productivity and nutritional quality.

Artificial-light plant factories allow crops to be grown year-round under tightly controlled conditions, but legumes such as edamame have historically been difficult to cultivate indoors due to their long growth cycles and complex flowering and pod-setting requirements.

The research team – led by professor Toshio Sano of Hosei University and associate professor Wataru Yamori of the University of Tokyo – set out to address these challenges.

In comparative trials, the team tested three hydroponic systems: nutrient film technique (NFT), rock wool culture (ROC) and mist culture (MIST). NFT produced the strongest growth, with plants developing sturdier stems, healthier leaves and greater overall biomass than those grown in other hydroponic systems or in open fields.

NFT-grown edamame also delivered the highest pod and seed counts, with yields exceeding those achieved through field cultivation. “Recent global warming and extreme weather events have raised concerns about reduced yields in open-field crop production. Our hydroponics technology offers a promising model for urban agriculture that is independent of climate conditions,” said professor Sano.

Quality analysis showed that NFT-grown edamame contained higher sucrose levels than field-grown crops, contributing to improved sweetness. While free amino acid levels were slightly lower, the NFT system produced significantly higher isoflavone concentrations – compounds associated with potential health benefits. The researchers suggested that LED lighting may help stimulate the synthesis of these bioactive components.

When yield, sweetness and nutritional value were evaluated together, NFT ranked highest overall. The technique is compatible with multi-layer vertical farming systems, making it suitable for dense urban areas where space is limited. According to the researchers, the technology could enable consistent year-round production and support future food security efforts.

The team also noted possible long-term applications in environments where traditional agriculture is not feasible. “Since edamame is cultivated not in open fields but through hydroponics in an LED-based plant factory, it may become possible to grow edamame even in urban areas, deserts or outer space,” added professor Sano.

The breakthrough overturns long-held assumptions about the feasibility of growing legumes in artificial-light plant factories and highlights the potential role of controlled-environment agriculture in addressing climate resilience, nutritional quality and global food supply.