Looking up soybean profit per acre to see whether the season will pay? The published figure is another farm’s average, and it changes with the date. For a rented acre of central Illinois soybeans, farmdoc’s 2025 budget, written in September 2024, showed a loss of $50. The 2025 actual, published in September 2026, showed $15 left over. So before you plant, write your own profit per acre for each crop, with the sum, the lines you take out and the date. At harvest, set the actual beside it: that comparison shows where the gap came from and what to change next season.
Why isn’t the published profit per acre yours?
Because it is the sum for a typical farm, with another farm’s yield, price and costs, and it changes with the date. Profit per acre here means what is left from an acre after you pay for growing it and rent the land: sales, plus government payments, less non-land costs and cash rent. Farmdoc calls it farmer return.
Non-land costs are what you spend to grow an acre: seed, fertilizer, chemicals, machinery, hired labor, insurance, interest and depreciation, among others. When costs pass sales, the profit becomes a loss.
The published figure changes within months, too. Between the May and September revisions of farmdoc’s 2026 budgets, projected returns on rented corn acres in northern and central Illinois went from a loss of about $50 to a return of $50 or $60. Soybeans went from $40 to $60 up to $90 to $116. The cause was mostly prices in the futures market and harvest cash bids.
To follow the reasoning, take a central Illinois farm on cash-rented, high-productivity land, half corn and half soybeans. In September 2024 it writes its 2025 sheets with farmdoc’s budget figures as its own; that choice belongs to the example. Use the published figure as a line to compare with, never as your target.
Why write it before you plant, and not at harvest?
Because once the result is in, your memory of what you expected moves toward it. Cassar and Craig, in 2009, followed 198 people who had stated how likely their new business was to start operating and who later quit. Asked afterwards, they recalled a figure well below the one they had given.
Those were people starting businesses, not farmers recalling a margin. The explanation narrows too: in Roese and Vohs’s 2012 review of hindsight bias, people who know the outcome settle on a single cause and grow overconfident in their own judgment. On a farm, a good year becomes skill and a bad one becomes weather.
Write the sheet and date it before you buy the inputs.
What goes on the sheet?
One crop per sheet, with five things: the sum, the lines you take out, what you expect per acre, the date, and one line on what the figure leaves out. A farm management manual from Buenos Aires province works its gross margin one crop at a time, before the season to plan and after it to check the result. The sheet does the same with profit per acre.
Name the lines, not the category: two people with the same books and two different lists get two different figures. Keep government payments on a line of their own, apart from crop sales.
Write what the figure leaves out on the same sheet. Here, what is left still has to pay your own labor and management, family living and debt principal.
Write next season’s sheet now, one per crop.
At harvest, how do you read the gap?
Set the actual beside each line of the sheet and see how much each line added to, or took from, what you expected. The total alone hides the cause.
| Line | Soybeans, sheet | Soybeans, actual | Corn, sheet | Corn, actual |
|---|---|---|---|---|
| Crop sales | $769 | $768 | $1,003 | $990 |
| Government payments and insurance payouts | $10 | $75 | $10 | $90 |
| Non-land costs | $490 | $502 | $747 | $806 |
| Cash rent | $339 | $326 | $339 | $326 |
| What is left | a loss of $50 | $15 | a loss of $73 | a loss of $52 |
On the soybean sheet, crop sales came within $1 of what was written, and the $65 came from payments. Without payments and insurance payouts, the acre lost $60, the same $60 you get from the sheet once you take out its $10 of payments. On the corn sheet, without them, the acre lost $59 more than written: the cost overrun.
Under each line, write why it missed, then no more than two or three other causes that could also explain it. Roese and Vohs report that weighing other explanations works best when kept to no more than two or three.
What does the comparison decide for next season?
Change on next season’s sheet the line that missed for a reason that can come back. A price miss changes the price line, not the acres. A payment stays on its own line, because you cannot count on it coming again. A yield or cost miss that repeats on the same field calls for a change of practice or of acres.
The FAO’s farm management extension guide says that a farmer deciding whether to keep a crop or grow another can compare the gross margins of the two, once family labor is counted. Compare two crops’ sheets only when both take out the same lines.
In the example, next season’s corn sheet gets a fertilizer line with a low and a high figure, because fertilizer cost $45 more than written. The soybean sheet keeps its crop lines and shows the payments apart. Wait for two seasons on the same field before changing the acres, because one season on its own may have been only a drought. That is a recommendation.
File the sheet where next season’s will be written, and put the date of the check on the calendar.
Where to start
Before this sheet comes the break-even price; for a rent or a loan over three seasons, see how to budget without a forecast.
The same column, the sheet beside the actual, works for any other line of farm management.