Corn vs. soybeans: Tips on what to plant on undecided acres

JOHNSTON, Iowa — The decision to plant corn or soybeans on undecided acres weighs on the minds of farmers heading into 2021.

“The important bottom line here is, there are a lot of scenarios that the conscious grower will want to run to make this highly impactful decision,” said Christopher Seifert, head of digital agriculture data science with Corteva Agriscience.

A simple equation can help farmers make the right decision: profit equals yield times price minus costs.

But the numbers vary by region, farm and field. So, farmers should run different calculations based on possible scenarios for next year.

There are many factors that influence a grower’s corn-versus-beans decision, Seifert said.

These include crop prices, effects of continuous cropping, equipment, rental agreements, contract obligations, inputs and more.

Seifert shared four things to keep in mind when making decisions for 2021:

1. Factor in grain markets. Soybeans are currently exhibiting strong cash prices, but wider negative futures spreads as compared to corn. Farmers should take both short- and long-term commodity outlooks into consideration when planning. Weather and planting pace in South America are also major factors to watch.

2. Acknowledge agronomic risk. Agronomic risks for continuous corn include nitrogen deficiency plus increased insect and disease pressure, while agronomic risks for continuous soy include herbicide resistant weeds, fungal pressure and diminished soil quality.

3. Contemplate changing up crop rotation. Yield drag on corn-on-corn acres is typically less than 1% with proper management, but as much as 5% in drier areas. Yield drag on soybeans-on-soybeans is typically around 11%, but as much as 21%.

4. Stick to profit-based decision-making. 2021 corn-versus-soybean rotation and planting decisions are specific to each farmer’s operation and management practices. To make the best data-driven decisions, it is important to compare the relative profitability of each field individually.

Farmers can access a free ROI calculator at http://granular.ag/cornvsbeansprofitabilitycalculator.