More local governments are extracting phosphorus from sewage sludge for fertilizer, aiming to reduce the country’s reliance on imports amid increasing global prices reflecting the Middle East tensions.
Phosphorus, essential for crop cultivation, is imported almost entirely from abroad. Supply disruptions triggered by Russia’s full-scale invasion of Ukraine in 2022 prompted the central government to promote fertilizer production from sewage sludge as part of efforts to strengthen food security.
Eight prefectural and municipal governments nationwide had 11 facilities to recover phosphorus from sewage sludge at the end of fiscal 2025, according to the infrastructure ministry.
Of the eight, Tokyo began operating a recovery system in January 2024 at its Sunamachi Water Reclamation Center in Koto Ward.
The Japanese capital tested vegetable cultivation using fertilizer derived from recycled phosphorus. Its effects were comparable to those of conventional fertilizer, a Tokyo Metropolitan Government official said.
The plan is for nationwide distribution of the fertilizer from fiscal 2026, cooperating with the National Federation of Agricultural Cooperative Associations, or Zen-Noh.
The city of Fukuoka, also among the eight, began operating a facility in April that can produce 300 metric tons annually at its Seibu Water Treatment Center. It is one of the country’s largest phosphorus recovery facilities.
The Fukuoka center uses technology that efficiently gathers phosphorus from sludge containing the chemical element in high concentrations, achieving roughly the same recovery volume as conventional facilities, although it is only half their size.
Japan’s annual phosphorus demand stands at about 300,000 metric tons, while sewage sludge generated nationwide each year contains an estimated 50,000 metric tons.
Production capacity, however, remains limited. The Sunamachi facility produces only about 70 metric tons annually.
“Production costs for recycled phosphorus are far higher than those of imports,” a metropolitan government official said, adding that technological advances and public aid are key to cost reduction.