MORROWFLY
Guided scenario

What if a severe La Niña hits South American crops?

La Niña's crop damage concentrates in Argentina and southern Brazil — corn and soy. Model a severe event. Note: a strong El Niño is underway right now, so this is the counterfactual.

1The setup

La Niña dries out Argentina and southern Brazil while wetting Australia — the damage concentrates rather than spreading evenly. The 2020–23 triple-dip brought Argentina its worst drought in 60 years: the last four months of 2022 saw 44% of average rainfall, soybean and corn yields fell roughly 40% below normal, and wheat output roughly halved. In 2010–11 a strong La Niña (ONI −1.7°C) coincided with the FAO Food Price Index hitting a then-record 238 points — though Russia's 2010 wheat export ban overlapped and is not attributable to La Niña. Farmdoc's yield analysis finds a strong La Niña link in Argentina, a weak one in the US, and none in Brazil. As of September 2026 the Pacific is tilting the other way — NOAA's Climate Prediction Center has an El Niño advisory on — so treat this as the mirror-image question. Argentina and Brazil together ship 55.9% of world soybean exports (2024 vintage).

2Right now

Soybeans

QUIET

Stress 3/10

  • Sorriso: week-ahead forecast shows severe deficit rainfall
  • Rosario: severe deficit rainfall — 32% of the 30-day normal
  • Harbin: severe deficit rainfall — 36% of the 30-day normal

Corn

WATCH

Stress 5/10

  • Sorriso: week-ahead forecast shows severe deficit rainfall
  • Pergamino: severe deficit rainfall — 39% of the 30-day normal
  • Zhengzhou: severe deficit rainfall — 20% of the 30-day normal

Monitor data as of Sep 24, 2026. Scores are observed readings, not forecasts.

How the shock travels

Argentine corn and soybean yields

La Niña dries Argentina's Pampas: the 2020–23 triple-dip cut soybean and corn yields roughly 40% below normal after the last four months of 2022 ran at 44% of average rainfall.

Evidence: USDA PSD + farmdoc yield analysis — 44% of average rainfall Sep–Dec 2022; yields ~40% below normal

Paraná River barging

Drought dropped the Paraná to its lowest in ~80 years, stranding grain barges and forcing lighter loads on the export route.

Evidence: River gauge reporting — lowest in ~80 years (2022–23)

Global food prices

The 2010–11 strong La Niña coincided with the FAO Food Price Index hitting a then-record 238 points, as drought hit wheat, corn, and soy stocks together.

Evidence: FAO Food Price Index — 238 points, Feb 2011 (then-record)

Caveat: Russia's 2010 wheat export ban overlapped and is not attributable to La Niña — the 2011 record had multiple causes

Australian wheat (offset)

La Niña wets Australia: the 2020–23 episode delivered record crops that partly offset South American losses.

Evidence: ABARES crop reports — record Australian crops 2020–23

3The exposure

Disruption hits:
  • Brazil
    53.6%
  • United States
    30.7%
  • Paraguay
    4.0%
  • Canada
    3.1%
  • Argentina
    2.3%
Share of global export value (USD) — 2024 vintage. Amber = the scenario focus. Ranked by share.

How the shock travels

Follow the shock downstream — from the soybeans market, through processors, to the shelf. These are the usual stages, not this scenario's outcome: exposure at each step, never a prediction.

  1. Day 0: soybean futures spike

    timing not established

    Lag basis: lag not established in sources reviewed

    soybean futures
  2. Soybean crushers and vegetable oil

    timing not established

    Lag basis: lag not established in sources reviewed

    cooking oilvegetable oilmargarinebiodiesel

    Archer-Daniels-Midland

    ADM

    Ag Services and Oilseeds segment crushes oilseeds into vegetable oils and oilseed protein meal; Carbohydrate Solutions converts corn and wheat into sweeteners, starches and ethanol

    Source: ADM 10-K summary (TradingView SEC filing report)

  3. Soymeal, animal feed and meat

    typically months (length not precisely quantified) →

    Lag basis: CRS Farm-to-Food Price Dynamics (R40621): time lags in retail price response to farm price changes are generally months in length, even for perishables like milk, meat, and fresh fruits and vegetables

    soybean mealanimal feedchickenpork

    Tyson Foods

    TSN

    Corn, soybean meal and other feed ingredients represented roughly 61% of the cost of growing a live chicken in fiscal 2023

    Source: Tyson Foods FY2023 10-K

Illustrative scenario. Not a prediction. Not financial advice. Company entries describe factual exposure to the commodity — not a view on any stock.

Trade map

Who ships it, who can’t do without it

2024 vintage · annual data, 1–2y lag

Sourced trade structure — the scenario’s shock geography at country resolution. Exposure, not a forecast.

Soybeans · Argentina + Brazil

Top exporters

  • Brazildominant

    53.6% of world exports

  • United Statesdominant

    30.7% of world exports

  • Paraguay

    4% of world exports

  • Canada

    3.1% of world exports

  • Argentina

    2.3% of world exports

Note: soya beans

Exposed importers

Shocked exporters: Argentina, Brazil

Strait of Malacca

via Strait of Malacca / Singapore Strait · 25% of global soybean exports

Source: Chatham House, 2015 (published 2017)

Everything through the Strait of Malacca →

Suez Canal

via Suez Canal

Route share unknown — No sourced figure; Brazilian soy to EU/Asia routing is split with no single published corridor share. Corridor-share research (Sep 2026): no commodity-specific corridor figure found in public sources -- not zero, just unsourced.

Everything through the Suez Canal →

How we map this

Exporter and importer shares are 2024 vintage · annual data, 1–2y lag from UN Comtrade and OEC (BACI/CEPII); an importer counts as exposed when ≥20% of its soybeans imports come from a shocked exporter. The shock geography is the scenario’s own focus selection. Annual data with a 1–2 year reporting lag — the structure moves slowly, the prices don’t.

4Adjust the assumptions

La Niña strength (ONI)Strong (−1.5 to −1.9°C)

Historical check: The closest episode, US drought, 2012, saw soybeans futures move +52.7% (large band); your 70% disruption setting sits in the large band.

What share of Argentina + Brazil’s soybeans exports is disrupted.

Resolution: Oceanic Niño Index ≤ −1.5°C in any overlapping 3-month season (NOAA Climate Prediction Center)

Share of world exports

Argentina + Brazil soybeans — 55.9% of world Soybeans exports (Share of global export value (USD) — 2024 vintage)

Exposed under your assumptions: 39.1% (55.9% × 70% severity)

The hatched area is modeled from your assumptions, not a measured outcome.

Exposed ≠ lost — affected trade can reroute, draw stocks, or substitute. This sizes the exposure, not the damage.

120d

Historical check: The closest episode, US drought, 2012, lasted 235 days (long); your 120-day drought duration sits in the medium band.

Resolution: Length of the growing-season moisture deficit (2022–23: four months at 44% of normal rainfall)

60d

Your assumption — not a measured buffer.

Resolution: Assumed days of stockpile cover — an assumption, not a measured buffer

Disruption timeline
090180270365 days
Disruption: 120 days
Assumed cover: 60 days — your assumptionYour assumption

60 days buyers can't ride out — not automatically a physical shortage

What this would have meant

At these settings, about 39.1% of the world's soybeans exports would be exposed to the disruption, and the disruption runs 120 days against 60 days of assumed stockpile cover, leaving about 60 days beyond what the assumed stockpile covers.

The closest recorded episode, US drought, 2012, saw soybeans futures rise +52.7% in 235 days (13 Jan 2012 → 4 Sep 2012), and for consumers: fats and oils (CPI, US) moved from -1.2% to -0.4% (no lag window was published for this episode). Illustrative — what happened then, not what will happen now.

What this assumes
  • Exposure: Target share 55.9% × severity 70% = 39.1% exposed.
  • Uncovered days: max(0, 120 − 60) = 60.
  • Exposed ≠ lost: affected trade can reroute, draw down stocks, or find substitutes — this number sizes the exposure, not the damage.
  • Exporter share ≠ spare capacity: rivals may not be able to surge supply to fill the gap.
  • Combined share is the sum of the focus exporters' individual shares — a scenario hitting all of them at once.
  • Stockpile cover of 60 days is your assumption, not a measured buffer.
  • Results are physical-exposure arithmetic from your stated assumptions — not a price forecast.

Analog check

Your settings look closest to US drought, 2012 (same commodity, same shock type, similar size, similar supply concentration). The episode's measured moves, caveats included: soybeans futures +52.7% in 235 days (13 Jan 2012 → 4 Sep 2012); Fats and oils (CPI, US): the retail move wasn't measured for this episode — the futures leg above and the farm-share bound below are all we can honestly say. The fats-and-oils basket spans palm, canola and other oils — palm oil prices fell through 2012; substitution across oils dilutes any soybean-only signal..

Only about 11.8¢ of every US consumer food dollar — and 18.5¢ of every food-at-home dollar — reaches the farm (USDA, 2024) — that's a ceiling, not a prediction: margins can absorb a spike or amplify it.

Illustrative — what happened then, not what will happen now. Your scenario differs: your 120-day disruption vs the episode's 235-day.

How we matched this
  • Commodity: requirement — Both are soybeans — non-soybeans episodes are excluded outright.
  • Shock type: 2/2 — Both are a drought shock.
  • Size: 1/1 — Your 70% disruption setting band: large; episode futures moved +52.7% (13 Jan 2012 → 4 Sep 2012) — band: large. Severity is % of shipments disrupted, not a price move: this banding is a v1 matching heuristic.
  • Duration: 0/1 — Your disruption: 120-day (medium); episode: 235-day (long) — trough-to-peak run-up window.
  • Supply concentration: 1/1 — Your hazard zone: 55.9% of world exports (high); episode disrupted ~40% (high) — US share of global soybean exports 2011/12 = 40% (USDA ERS, Oil Crops Outlook OCS-12e, May 2012).

Score 4/5 — close analog (headline).

Want the full controls? Reopen soybeans on its commodity page.

5What happened before

For perspective, not prediction

El Niño: the climate driver that doesn't always deliver

Recurring — 2009-10, 2015-16, 2023-24

“El Niño moves the weather, not always the price. In 2015–16 wheat fell sharply but tracked outcomes were mixed (rice +7.7%, soy +2.1%) while sugar spiked — fear the mechanism, measure the outcome.”

Price moves were observed around the event — not proof the event caused the entire move.

Read the full record

What to watch

  • NOAA CPC's monthly ONI table — severe La Niña means ≤ −1.5°C in any overlapping 3-month season
  • Rainfall across Argentina's Pampas and southern Brazil through the growing season (2022 ran at 44% of average)
  • Paraná River levels — drought dropped it to its lowest in ~80 years, stranding grain barges
  • USDA WASDE cuts to Argentine corn and soybean production estimates
  • The active El Niño: CPC's advisory and strength probabilities show which way the Pacific is actually tilting

Curated by Morrowfly — these are things to check, not monitor conditions.

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Read by a human · never auto-published

Illustrative scenario. Not a prediction. Not financial advice.

Monitor data as of Sep 24, 2026 · Trade vintage 2024 · Scoring v3.2

What if a severe La Niña hits South American crops? | Morrowfly