# The Impact of Preseason La Niña Episodes on Corn and Soybean Yields in Brazil and Argentina

> A farmdoc daily analysis by Scott Irwin, dated December 17, 2020, examines South American corn and soybean yields in past La Niña years. It compares the USDA December forecasts for Brazil and Argentina with the current La Niña episode. The study aims to determine whether trend yield expectations should be adjusted.

- Date: 2021-01-01 · published 2021-01-01T12:00:00.000Z
- Category: weather · region Brazil · magnitude medium
- Page: https://feedsoft.ai/events/49571-the-impact-of-preseason-la-nina-episodes-on-corn-and-soybean-yields-in-brazil
- Commodities: [Corn](https://feedsoft.ai/c/CORN.md), [Soybeans](https://feedsoft.ai/c/SOY.md)

## Why it matters

If past La Niña years show yield shortfalls in Brazil and Argentina, South American supply could tighten and support corn and soybean prices. The analysis is a research view, so the price impact depends on how it shapes trade expectations.

## Read by commodity

- SOY: bullish ▲
- CORN: bullish ▲

## Similar past events

| Commodity | Date | Event | 5-day % | 20-day % |
| --- | --- | --- | --- | --- |
| CORN | 2026-02-11 | [Lack of rain pressures corn and soybeans in the South](https://feedsoft.ai/events/13451-lack-of-rain-pressures-corn-and-soybeans-in-the-south.md) | -0.5% | +1.7% |
| CORN | 2023-12-04 | [Delayed Soybean Planting to Impact Safrinha Corn Acreage in Brazil](https://feedsoft.ai/events/13607-delayed-soybean-planting-to-impact-safrinha-corn-acreage-in-brazil.md) | +1.7% | +3.1% |
| CORN | 2024-09-18 | [Will a Very Dry End to Growing Season Impact Corn and Soybean Yields? Missy Bauer Explains on Unscripted. - AgWeb](https://feedsoft.ai/events/13155-will-a-very-dry-end-to-growing-season-impact-corn-and-soybean-yields-missy.md) | -1.2% | -3.1% |
| CORN | 2025-01-15 | [Very Dry Last Half of Growing Season Took top End Off US Corn, Soybean Yields](https://feedsoft.ai/events/13119-very-dry-last-half-of-growing-season-took-top-end-off-us-corn-soybean-yields.md) | +2.0% | +2.6% |
| CORN | 2021-08-18 | [La Niña’s Likely Return Could Impact Brazil, US Corn](https://feedsoft.ai/events/45487-la-nina-s-likely-return-could-impact-brazil-us-corn.md) | -1.4% | -10.1% |
| SOY | 2022-06-01 | [Third Consecutive La Niña? What to Expect from Soybean Yields in the United States, Brazil and Argentina](https://feedsoft.ai/events/41333-third-consecutive-la-nina-what-to-expect-from-soybean-yields-in-the-united.md) | +2.7% | -0.5% |
| SOY | 2020-08-24 | [La Nina could impact soybean planting in Brazil, Argentina - Brownfield Ag News](https://feedsoft.ai/events/51519-la-nina-could-impact-soybean-planting-in-brazil-argentina-brownfield-ag-news.md) | +5.5% | +13.5% |
| SOY | 2026-02-11 | [Lack of rain pressures corn and soybeans in the South](https://feedsoft.ai/events/13451-lack-of-rain-pressures-corn-and-soybeans-in-the-south.md) | +1.0% | +6.9% |

## Sources

- farmdocdaily.illinois.edu: https://farmdocdaily.illinois.edu/2020/12/the-impact-of-preseason-la-nina-episodes-on-corn-and-soybean-yields-in-brazil-and-argentina.html

---
Data from Feedsoft AI (https://feedsoft.ai/). For information only; not investment advice.