Gaia Series 69: Make the most of the "troublesome things" - SDGs starting with bamboo

From bamboo shoots to revolutionary bamboo-reinforced concrete, this episode explores Japan's innovative approaches to harnessing and preserving bamboo resources.

In the serene setting of Otaki City, Chiba Prefecture, spring marks the arrival of bamboo shoot season, a time when locals and tourists alike celebrate this culinary delight. Restaurants specialising in bamboo dishes welcome throngs of visitors daily. The highlight is the bamboo shoot sashimi, a dish praised for its soft texture and mild flavour. “It’s delicious,” remarks a diner savouring the seasonal treat. The unique white shoots are a product of the region’s clay soil, which limits light penetration, creating its delicate flavour.

However, the abundant growth of bamboo is not without its challenges. In Aizumisato City, Fukushima Prefecture, unchecked bamboo groves have become a pressing issue for farmers like Kazuko Takahashi. The overgrown forests attract wild boars, deer, and even bears, causing damage to crops and threatening the local ecosystem. “The corn was wiped out in one night,” Takahashi says, showing footage from a sensor camera capturing wild animals feeding on the bamboo shoots.

While these challenges persist, innovative efforts to utilise bamboo are emerging across Japan. In Kyoto, the Menma Project is tackling the problem by transforming overgrown bamboo into menma, a fermented bamboo shoot widely used in ramen. Masahiko Kubota, the CEO of ramen restaurant chain Shining Bird, leads this initiative, aiming to reduce Japan’s reliance on imported menma. He explains, “Since ramen shops use plenty of menma, addressing the issue of abandoned bamboo forests through local production made sense.”

Kubota collaborates with farmers like Hitoshi Sato,  who now harvests bamboo for the project. 82-year-old Sato, the leader of a local group maintaining bamboo forests, notes, “No one has ever asked me how much bamboo they could take before.” This spring, Sato’s group harvested over 200 young bamboos, selling them to the Menma Project for 1,000 yen each. This arrangement not only generates income for local farmers but also ensures the forests are well-maintained.

Kubota’s restaurants now serve dishes featuring Kyoto-grown menma, with diners praising its crunchiness and fresh taste. Plans are underway to expand the use of local menma across all 21 of Kubota’s restaurants next year. Other restauranters are also looking to utilise menma in their dishes. In particular, Satoshi Harim, who owns six Korean restaurants in Tokyo and Kyoto, has been experimenting with menma in dishes such as cold noodles and japchae. This surge in interest has created a market for domestically produced menma, which not only supports local agriculture but also revitalises neglected bamboo forests.

Meanwhile, in Fukushima, civil engineer Akihiko Takahashi is spearheading the revival of bamboo-reinforced concrete, a technique developed during World War II when metal shortages led to the use of bamboo as a substitute for steel. Takahashi, 62, believes this forgotten method could address modern environmental challenges while reducing reliance on steel. “The destruction of nature, like landslides, could decrease if we industrialise bamboo use,” he explains.

The strength and flexibility of bamboo make it an intriguing alternative to steel in certain applications, such as U-shaped gutters and secondary concrete products. In Minamiaizu City, where heavy snow and rain test infrastructure resilience, bamboo-reinforced gutters are being trialed. Early experiments show promise, with bamboo providing reinforcement that prevents concrete from cracking under stress. Additionally, using bamboo instead of steel could reduce CO2 emissions by 680,000 tons annually, equivalent to a forest covering a quarter of Tokyo.

Despite these benefits, challenges remain. The cost of producing bamboo-reinforced concrete is currently high, with bamboo rebars costing twice as much as steel. To overcome this, Takahashi collaborates with experts like Professor Yasuhiro Koda of Nihon University, who is working to optimise production methods. Professor Koda highlights bamboo’s ability to make concrete bend rather than break, adding, “It truly becomes a reinforcement.”

Efforts to streamline the process include the development of machinery tailored to bamboo’s unique properties. Professor Riuji Sugiura, a mechanical engineer, designed a cutting machine that ensures consistent results despite variations in bamboo thickness and curvature. This innovation marks a significant step towards scaling up bamboo-reinforced concrete production.

The episode concludes with a demonstration of bamboo-reinforced gutters in a rural waterway. Residents of Minamiaizu City, initially sceptical, express admiration for the project after learning about its potential to mitigate flooding and environmental damage. Takahashi’s passion for the project is evident as he states, “Connecting everyone to create something was most important to me.”

As Japan grapples with the challenges posed by abandoned bamboo forests, these initiatives demonstrate how tradition and innovation can coexist to create sustainable solutions. From the delicious bamboo shoots of Otaki to the groundbreaking bamboo-reinforced concrete of Fukushima, this episode highlights the resilience and ingenuity of those working to turn a problem into a valuable resource. With each project, bamboo is being reimagined not as a nuisance, but as a vital part of Japan’s cultural and environmental heritage.