Kagoshima: Farmer sees pumice problem as opportunity

By Daiki Iseri / Yomiuri Shimbun Staff Writer

18:50 JST, January 28, 2022

ISEN, Kagoshima — Pumice ejected from the undersea volcano Fukutoku-Okanoba near the Ogasawara Islands has been washing up on Okinawa Island and remote islands in Kagoshima Prefecture since late last year, greatly affecting the fishing and tourism industries.

However, what is a nuisance to some looked like an opportunity for the owner of three coffee groves on Tokunoshima island in Kagoshima Prefecture.

“Pumice is the savior of coffee farms,” said Hiroshi Miyade, a 45-year-old representative of the company Tokunoshima Coffee Farmers.

Tokunoshima sees a lot of rainfall in February and March, when the coffee beans are harvested, and the quality of the beans tends to decline due to too much moisture in the soil. Most of the soil on the island is red clay soil, which makes it difficult for coffee trees to take root, and growth tends to be slow.

Coffee farmers there have been trying to improve the soil on their farms by mixing in volcanic-derived soil, such as Kanuma soil and Hyuga soil.

When Miyade heard that pumice had drifted ashore, he thought the pumice could make for a nice addition to the soil as it is also created by volcanoes. He has been working since October to improve drainage and the breathability of his farms’ soil by mixing in the pumice found along the shores.

He soaks the pumice in water for a certain period of time to remove salt, dries it in the sun, and then mixes it with the soil. Miyade has already used the pumice for 200 of the 2,000 coffee trees in his groves on the island.

Coffee bean production on Tokunoshima began 30 to 40 years ago, and there are currently about 30 coffee farmers, according to the local municipality of Isen.

Generally, it takes about 5 years — from sowing to harvesting — to produce coffee beans. It will be a few years, at least, to see if the quality of the beans has improved. However, whether the trees’ growth rates have improved should be known within a few months, Miyade said.

“I want to use it for the soil for 1,000 new trees that I plan to plant this spring,” Miyade added.