Phosphorus Depletion and Natural Farming Series
Chapter 1 / Essay
Chapter 1 № 01 · 2026

Three supply routes,
thinning at once.

China, sulfur, PFAS — three routes are thinning at once

2026.05.06 🌐 日本語

Phosphate fertilizer is one of the three pillars of chemical fertilizer (nitrogen, phosphate, potassium). It is essential to plant growth, and is involved in particular with root development, flowering, and fruiting.

Where nitrogen fertilizer is called "the fertilizer that grows leaves" and potassium "the fertilizer that grows fruit," phosphate is called "the fertilizer that grows roots and flowers." Without phosphate, plants cannot extend roots, cannot form flower buds, cannot bear fruit.

Chemically and geoscientifically, phosphorus is also distinctive. Nitrogen is in the same Group 15 (the pnictogens), and via the Haber–Bosch process can be synthesized without limit from atmospheric nitrogen — but phosphorus, the same pnictogen, depends solely on rock phosphate, a finite, depletable resource present in the Earth's crust. There is no industrial substitute [source: Phosphorus dynamics, PMC11647644].

For this phosphate fertilizer, Japan depends on imports for 100% of the raw materials (self-sufficiency 0%) [source: MAFF, "Situation Surrounding Fertilizer," April 2026 edition].

The amount produced domestically is zero. Most of the chemical fertilizer that supports modern agriculture arrives by ship. If the ships stop, the fertilizer does not come.

Broadly, there are three supply routes. And all three are thinning, at the same time.

Route 1: Imports of finished product via China

The center of Japan's phosphate fertilizer supply remains China.

China is one of the world's largest rock phosphate producers, with the integrated capacity to process the rock domestically into finished products such as ammonium phosphate ((NH4)H2PO4 or (NH4)2HPO4).

Actual data for fertilizer year Reiwa 6

According to the latest data published by the Ministry of Agriculture, Forestry and Fisheries (MAFF) on April 24, 2026, the structure of Japan's main fertilizer imports in fiscal year 2024 (Reiwa 6) (July 2024 – June 2025) is as follows [source: MAFF, "Situation Surrounding Fertilizer"].

Fertilizer category Main source countries and shares Total imports
Urea (nitrogen feedstock) Malaysia 74%, Vietnam 10%, Saudi Arabia 5%, China 3% 256,000 tons
Ammonium phosphate China 72%, Morocco 21%, Israel 7% 370,000 tons
Potassium chloride Canada 78%, Israel 7%, Jordan 4%, Laos 3% 228,000 tons

Dependence on China for ammonium phosphate has run:

— a stepwise decline, down 18 points. This is the result of the government and fertilizer makers diversifying procurement (Morocco, Israel, etc.). Even so, the structure of more than 70% concentration in a single country (China) remains.

And the world's rock phosphate reserves are extremely uneven, with China and Morocco together holding roughly 70% of the total. This geopolitical fragility persists as a structural risk to Japan's agricultural foundation.

March 2026: China's de facto export halt

This route thinned rapidly after the start of 2026.

On March 14, 2026, the Chinese government abruptly and de facto suspended exports of urea, DAP (diammonium phosphate), and MAP (monoammonium phosphate). The measure runs about half a year, through August [source: iru-miru.com 82119].

The timing falls on Japan's decisive spring–summer demand window. The drivers are these.

National food security as priority

China makes feeding a population of roughly 1.4 billion its top priority. Amid normalized abnormal weather and global supply-chain disruption, it has structurally tightened exports to channel fertilizer to domestic agriculture and head off social unrest from food-price spikes (food inflation).

Expanding LFP battery demand

Demand for lithium iron phosphate (LFP) batteries has exploded across EVs, stationary storage, and smartphones. LFP cathode manufacturing requires large quantities of high-purity phosphoric acid at a different grade from the agricultural one.

From an economic-rationality view, there is little incentive for fertilizer makers to keep agricultural lines running — those products carry low value-added and are easily caught by government price controls. Limited resources (equipment, feedstock, personnel) get reallocated toward industrial phosphoric acid for LFP batteries, which trades higher.

"The push for decarbonization destroys food security." This trade-off functions as a structural force shrinking the agricultural-phosphate supply pie irreversibly and permanently.

Geopolitical pressure

In recent years, China has restricted exports of strategic materials — rare earths, gallium, germanium, graphite. Phosphate fertilizer is being folded into the same line.

These overlap, and from spring 2026 onward Japan's import volumes have fallen sharply.

Route 2: Rock phosphate imports + domestic processing

Aiming to break out of dependence on China, the Japanese government and domestic fertilizer makers (Katakura Co-op Agri, Taki Chemical, and others) have promoted an alternative route: importing unprocessed rock phosphate directly from Morocco, Jordan, the United States and elsewhere, and processing it into phosphate fertilizer at their own domestic plants.

Active resource diplomacy — including a May 2022 visit to Morocco by then-Vice Minister Takebe of Agriculture, Forestry and Fisheries — has helped, and Morocco's share has risen sharply.

But here too, problems are emerging.

The sulfuric-acid bottleneck

Processing rock phosphate into fertilizer requires large volumes of sulfuric acid. Hard-to-dissolve rock phosphate (mainly calcium phosphate) is broken down with sulfuric acid into a form plants can absorb (such as superphosphate). This is the core of the industrial process.

Without sulfuric acid, rock phosphate alone does not become fertilizer.

The feedstock for sulfuric acid — sulfur — is, in modern industrial structure, produced as a by-product of the desulfurization step in oil and natural-gas refining. Japan is extremely dependent on the Gulf states of the Middle East — Saudi Arabia, the UAE, Qatar — for its supply of this sulfur and of fossil fuels.

Even if rock phosphate could be sourced smoothly from Africa, if energy and sulfur from the Middle East are interrupted, Japanese plants cannot run the chemistry, and cannot produce fertilizer. The weak point is indirect, but built in, and lethal.

2026: QatarEnergy's force majeure declaration

This structural weak point surfaced in the worst possible form in 2026.

As Middle East tensions escalated sharply, QatarEnergy — one of the world's leading export hubs for natural gas, the main feedstock for nitrogen fertilizer — was hit by a direct Iranian drone strike and forced into a temporary production halt. The company declared force majeure, the contractual clause that releases it from supply obligations on grounds of war or other uncontrollable events [source: central-green.jp, latest fertilizer prices 2026].

A unilateral supply stoppage was carried out legally, without exposure to damages, and raw-material procurement costs surged.

Strait of Hormuz: one-third of global fertilizer trade

On top of that, the international chokepoint through which roughly one-third of global seaborne fertilizer trade (16 million tons a year) passes — the Strait of Hormuz — has fallen into severe disruption from the conflict [source: Strait of Hormuz Disruption Scenarios, farmdocdaily].

A scenario analysis by NDSU's (North Dakota State University) Agricultural Trade Monitor suggests the price surge is not a transient shock but a hit to the long-term farmer purchasing cycle.

Scenario Forecast urea peak (NOLA index) Duration above $700/st
Early reopening $782 per short ton (June) Eases by Q4
Continued passage disruption $784 (July) Drags into November
Prolonged conflict $996 (October) Continues indefinitely into the next year

Recent prints: urea is up 53.7% month over month at $725.6/ton (a four-year high), with DAP at $658.3 (+5%) and potassium chloride (MOP) at $380.6. The World Bank forecasts fertilizer prices to rise more than 30% during 2026 [source: World Bank Commodity Markets Outlook].

If sulfur does not arrive, sulfuric acid cannot be made. Without sulfuric acid, rock phosphate cannot be processed. By a different path from Route 1, phosphate fertilizer simply cannot be produced.

Middle East conditions and phosphate fertilizer are connected — indirectly, but reliably.

Route 3: Sewage-sludge recovery — the Green Food System Strategy and the PFAS shackle

With the first and second import routes near collapse, the route the Japanese government is pushing as national strategy is the establishment of a recycling route (Route 3) that recovers and reuses phosphorus from domestic underused resources (sewage sludge, livestock-manure compost, and the like).

The Green Food System Strategy

As part of MAFF's "Green Food System Strategy" for sustainable agriculture, the government has set ambitious policy targets:

[source: smartagri.jp, commentary on the situation surrounding fertilizer]

In theory, the recoverable potential from Japan's sewage sludge is estimated at about 50,000 tons per year, and that potential is critical for easing import dependence. Concrete deployments include:

The fatal shackle of PFAS regulation

But there is a fatal wall blocking full deployment of this recycling route: the broad contamination problem from PFAS (per- and polyfluoroalkyl substances).

PFAS is the umbrella term for thousands of synthetic chemicals used in water repellents, frying-pan coatings, firefighting foam, fluoropolymers, and more. They resist breakdown in nature so strongly they are called "forever chemicals." They tend to accumulate at high concentration in sludge that gathers at sewage-treatment plants (including ISSA: incinerated sewage-sludge ash).

Regulation is moving fast.

Compared with international regulation, however, Japan's standard remains lenient. In April 2024, the United States proposed new rules with extremely strict thresholds of "under 4 ng/L" for PFOS and PFOA each on their own. The 4 ng/L figure is essentially the limit of quantification of current testing, equivalent to demanding "no detection at all" — zero tolerance.

Measured PFAS data on domestic sewage-sludge fertilizer

A 2024 PFAS survey of sewage-sludge fertilizer by the Japan Family Farmers Movement Food Analysis Center tells the story of how serious the contamination is [source: shiryo_setagaya_pfas_250510a].

Sample collection area PFOS+PFOA combined detection in fertilizer (µg/kg) Assessment
Prefecture S sewage-sludge fertilizer 103.4 Markedly high accumulation. Unusable under US/EU standards
Prefecture O sewage-sludge fertilizer 21.3 Significant accumulated contamination
Prefecture W sewage-sludge fertilizer 3.1 Relatively low, but accumulation risk remains
Prefecture K sewage-sludge fertilizer 1.5 Same as above

The 103.4 µg/kg detected in Prefecture S — when one accounts for soil accumulation from long-term application to farmland, leaching to groundwater via rainfall, and migration into crops with potential carcinogenic and immune effects in humans — is a deeply troubling level.

If strict safety standards were applied, much of the sewage-sludge fertilizer now in circulation would likely fall out as non-conforming and be discarded. To clear them requires a fundamental infrastructure upgrade to the sewage-treatment process itself — adding PFAS adsorption / breakdown steps (activated-carbon treatment, advanced oxidation, etc.). Rolling that out across treatment plants nationwide takes "years to a decade and large investment."

That is, the recycling route cannot be a fast-acting source of supply.

How the three routes thin at once

In summary:

Route Status
1. Imports from China Structurally shrinking from national security + LFP demand; de facto halt March 2026
2. Rock phosphate processing Sulfuric-acid (Middle East sulfur) constraint; QatarEnergy force majeure declaration; Strait of Hormuz disruption
3. Sewage-sludge recovery Small in scale; PFAS regulation strips it of immediacy

All three are thinning at the same time, for independent reasons. This is not a coincidental simultaneity — it is each route's structural constraint surfacing in the same period.

Prices and the rigidity of the domestic market

Retail prices of superphosphate (20 kg bag) for domestic farmers, in lockstep with global fertilizer prices, have moved like this [source: smartagri.jp]:

Year Domestic farmer retail price Global compound fertilizer price
2020 1,800 yen Pre-shock baseline
2021 2,150 yen Rising
2022 3,400 yen (peak) $815/ton (about 3x baseline)
2023 3,200 yen Declining
2024 2,900 yen $327/ton (well off the peak)

What stands out is that even after global prices fell from the 2022 peak of $815/ton to $327/ton in 2024 — less than half — domestic retail held high at 2,900 yen. The main reason is the historic weakness of the yen. Even when dollar-denominated prices fall on the international market, FX depreciation fully offsets the import-cost relief. For ammonium phosphate, the situation is far from a return to baseline.

Government stockpile and demand-supply simulation

Under the Economic Security Promotion Act, the government has designated ammonium phosphate as a "specified critical material" and set a target of stockpiling "three months" of annual demand by FY2027 [source: smartagri.jp].

As of April Reiwa 8 (2026), the stockpile has reached "2.4 months." Spring-demand fertilizer for the domestic market has already been manufactured using last year's feedstock inventory and is in distribution, and so the government (MAFF) has put out the line that "excessive concern is unwarranted."

However:

— these become unavoidable. The current 2.4-month stockpile is no more than a temporary shock absorber; if new procurement routes remain cut for more than half a year, the autumn 2026 crop's consumption begins to bottom out domestic inventory in earnest.

The risk that farmers cannot buy fertilizer in the volumes they want — an "allocation (rationing) state" — is extremely high.

Not a "crisis" — a structural story

What I want to stress here is that this is not a "crisis."

The word crisis suggests an unforeseen shock. It implies some special event has happened, that the normal state has been disturbed.

But what is happening now is different.

Each is a structural factor; each persists long term. Not a crisis; the structure has surfaced. That is the form of what is in front of us.

Look at the supply-chain structure, and this is what you see.

This is not a failure of agricultural policy, nor anyone's conspiracy. World mineral resources, geopolitics, industrial demand, environmental regulation, FX — every structure is moving simultaneously in the direction of thinning the phosphate-fertilizer supply.

People can only accept the consequence.

In the next chapter, we confirm — through the economics of low-grade ore and peak phosphorus — that this is not a temporary shock but the entry point into a long era of high prices.

References

Government and public bodies

Industry reports and commentary

Academic literature

PFAS-related