A spicy agricultural heritage: there’s more to wasabi than meets the eye

01/04/2021

With its distinctive green colour and sharp, spicy flavour, wasabi (Eutrema japonicum) has been highly prized in Japan for centuries. There is evidence from written works that Buddhist monks ate “cold wasabi soup” from as early as the 12^th century. By the 14^th century, they began to eat sashimi topped with wasabi vinegar, and from then on, wasabi started to appear in the meals of the public. Now, it is eaten all over the world.

The native wasabi plant comes from the Shizuoka region of Japan, where cultivation began around 400 years ago. Since then, wasabi farmers have been perfecting their production methods, culminating in the incredible system that makes the most of the area’s natural resources to create the sustainable, practical way of farming that is used today. In 2018, FAO designated the wasabi farms in the Shizuoka region as a Globally Important Agricultural Heritage Systems (GIAHS), recognising the area for its agricultural traditions and cultural significance.

A family business

Kichie Shioya is a wasabi farmer in Shizuoka, just as his father, grandfather and great-grandfather were before him. It’s something of a family business. Now, he is the Director of the Shizuoka Wasabi Union Federation and well-versed in the peculiarities of the system that makes wasabi farming so special.

“Wasabi is a special plant,” Kichie says. “If the water becomes muddy, the wasabi roots are likely to rot. Water should always contain abundant oxygen.”

That’s why regulating water is such a critical part of the agricultural system in Shizuoka. Land is farmed in the Tatamiishi style, which was developed in the late 1800s. According to this style, sloping land is made into a series of terraces, large rocks, stones and sand, which act as a natural filter for the enormous quantities of spring water that flow over the wasabi fields. This Tatamiishi style of cultivation lets water permeate the soil without stagnating, naturally regulating the influx of water and draining out any surplus. The plentiful spring water in the region is also stable at approximately 13°C year-round, which heats or cools the wasabi to keep it at a temperature suitable for growth.

“Water streams down and soaks into the soils where wasabi is planted, allowing clear water to be drawn in,” Kichie explains. “Step by step, the water gets clearer. Our area has a lot of pumice stones made from volcanic ashes, which soaks water well, so that ground water is abundant.”

Protection against natural disasters

The Shizuoka area is prone to natural disasters, something that has caused havoc for decades of wasabi farmers. 1958 brought particularly destructive typhoons, which lashed down on the wasabi fields, leaving only five percent of crops undamaged. This was a turning point and led to the entire farming system being reconstructed to make it more resilient to future flood damage. 

Since then, the industry has recovered slowly and put in place vital protection from harsh weather: water pathways have been built and riverside infrastructure implemented. The Tatamiishi style’s natural water regulation system also helps to increase the resilience of the wasabi plants to flooding and adverse weather by reducing the flow of water. These preventative water management processes are one of the most important parts of wasabi faming.  

Another natural risk to wasabi cultivation is higher temperatures caused by climate change. Wasabi plants must be sheltered from direct sunlight from spring to autumn. To do this, East Asian Alder trees native to the area are planted in wasabi fields to create shade.

“Global warming is one of our challenges. Extremely hot summers cause bigger damage to our production,” Kichie says. “It takes about one and half years to grow wasabi. We need to pay careful attention - particularly in the early stage of the plants – that they are not attacked by pests or damaged by heat and strong sunlight. “

Wasabi farmers have a great respect for the entire ecosystem, recognising that each part, from trees to the area’s biodiversity, plays a role in protecting the wasabi plants. In fact, the traditional agricultural system is a natural habitat for many endemic fauna and flora species.

“Pesticide use is highly limited as it goes into the water and the water will go into local rivers. Because of this, I am proud of the rich nature in our area, as well as the clean and good quality water. We have abundant insects and fish. You will also find fireflies,” Kichie says.

Adapting to new situations

COVID-19 has hit many in the agricultural sector particularly hard. The wasabi industry was no different.

“After the GIAHS designation, the demand increased, for which we were thankful. But the COVID-19 pandemic has hugely affected the food industry, and we have faced a high decrease of our wasabi sales to the major companies, who are the main customers for our genuine wasabi,” Kichie says.

With restaurants closed, the wasabi farmers directed their sales towards big retailers and supermarkets, hoping to reach more private homes.

“We adapted to the situation by shifting sales to major retailers as individual consumer spending is on the rise, to a certain extent.”

Whatever the challenge, whether it’s global warming or a pandemic, Shizuoka’s wasabi farmers have a remarkable ability to adapt their systems and continue their livelihoods.

Producers are proud of their wasabi fields and see it as a valuable heritage passed on from their ancestors. The wasabi farming techniques are ingrained in the community’s history, and farmers work together to keep them safe. Through the GIAHS initiative, sites like wasabi-producing region of Shizuoka, are given recognition and support so that these unique agricultural methods can continue to not only be passed down through families but also to serve as a model for others to follow.

Related links

Learn more

• Website: GIAHS: Traditional Wasabi Cultivation in Shizuoka, Japan
• Story: Now is the time to restore our ecosystems!