All-natural: Farmer Nobuyoshi Fujiwara spreading human faeces-made fertiliser over the lettuce field at his farm in Yokosuka, city of Kanagawa prefecture. — AFP
It’s cheap, recycled, and has centuries of tradition: “shimogoe” or “fertiliser from a person’s bottom” is finding new favour in Japan as Ukraine’s war hikes the price of chemical alternatives.
As in several parts of the world, the use of “night soil” to fertilise crops was once common in Japan.
However, the advent of sewage systems and treatment facilities, as well as chemical fertilisers, saw it fall out of fashion.
About a decade ago, Japanese treatment facilities wondered if they could revive interest to avoid sewage sludge disposal – a costly and potentially environmentally damaging process.
But enthusiasm was limited until Russia’s invasion of Ukraine sent the cost of chemical fertilisers soaring.
That has been a bonanza for a facility in northern Japan’s Tome, where sales of shimogoe were up 160% year-on-year by March 2023.
For the first time since the city began producing the fertiliser in 2010, it has sold out.
The demand is easy to explain, said facility vice president Toshiaki Kato.
“Our fertiliser is popular because it’s cheap, and it is helping farmers cut soaring costs,” he said.
“Plus it’s good for the environment.”
Made of a combination of treated sewage sludge from septic tanks and human waste from cesspits, the fertiliser goes for 160 yen (RM5.17) per 15kg.
That’s about a 10th of the price of products made from imported raw materials.
In south-western Japan’s Saga too, officials report sales are up two to three times.
Shimogoe was a key fertiliser in Japan’s pre-modern Edo era, said Arata Kobayashi, a fertiliser specialist who has written journal articles on the subject.
In the early 18th century, the one million residents of Tokyo –then called Edo – “produced” an estimated 500,000 tonnes of fertiliser a year.
It was big business, involving gatherers, transporters and farmers, “and all of them benefited from the recycling system,” Kobayashi said.
Japan’s government has encouraged the revival, citing environmental benefits, and concerns about food security since Russia’s invasion.
The ministry of agriculture, forestry, and fisheries hopes to double animal manure and human waste use by 2030, with a goal of them accounting for 40% of all fertiliser use in Japan.
In Miura outside Tokyo, vacuum trucks carrying human waste arrive one after another at a treatment facility.
“We produce 500 tonnes of fertiliser annually,” said Kenichi Ryose, facility manager at Miura Biomass Centre.
“This fertiliser is particularly good for leaf vegetables, like cabbage,” he added. — AFP
