Japan has seen a resurgence in the use of “shimogoe,” a traditional fertilizer made from human waste. This eco-friendly and cost-effective fertilizer, which has deep historical roots in Japan, is making a comeback as the prices of chemical alternatives skyrocket due to Ukraine’s war.
In the past, “night soil” (human waste used as fertilizer) was a common practice in Japan, but it faded out of use with the development of sewage systems and chemical fertilizers.
However, the ongoing conflict in Ukraine has led to a significant increase in the cost of chemical fertilizers, making “shimogoe” an attractive alternative for farmers. Sales of this traditional fertilizer in northern Japan’s Tome have surged by 160 percent year-on-year, with the city experiencing its first-ever sellout since its production began in 2010.
Toshiaki Kato, the vice president of the facility producing “shimogoe,” explains the appeal: “Our fertilizer is popular because it is cheap and helps farmers reduce their expenses. It is also environmentally friendly.”
This traditional fertilizer is made by combining treated sewage sludge from septic tanks with human waste from cesspits. It is available at a cost of 160 yen ($1.10) for 15 kilograms, which is only a fraction of the price of imported chemical fertilizers.
In southwestern Japan’s Saga, sales have also doubled or even tripled, and other municipalities are eager to replicate this successful program.
Historically, “shimogoe” played a vital role in Japan’s pre-modern Edo era, with Tokyo (formerly Edo) residents producing substantial quantities of fertilizer from human waste. It was a profitable business, benefiting gatherers, transporters, and farmers alike.
Japan’s government has been actively encouraging the revival of this traditional practice due to its environmental benefits and concerns about food security following Russia’s invasion of Ukraine. The Ministry of Agriculture, Forestry, and Fisheries aims to double the use of animal manure and human waste as fertilizers by 2030, with a target of accounting for 40 percent of all fertilizer use in Japan.
In Miura, outside Tokyo, a treatment facility processes human waste into a soil-like powder suitable for agricultural use. Methane produced during the process is used to generate hot water and electricity.
While “shimogoe” is gaining popularity, it does face challenges, including its distinctive odor and the need for larger quantities compared to chemical fertilizers. Additionally, the negative connotations associated with human waste fertilizers, including the Chinese characters for “sludge” being used, pose marketing challenges.
Despite these challenges, some farmers like Nobuyoshi Fujiwara, who runs a lettuce farm, believe in the potential of this traditional fertilizer and hope for official certification to promote their produce.