Recalculate cost of production after planting – Ugh! Why bother?

By Wm. Bruce Clevenger, Ohio State University Extension, Field Specialist, Farm Management

After corn and soybeans are in the ground, the last thing many farmers want to do is revisit the numbers. Planting is stressful enough — why dig back into cost of production? The short answer is simple: A lot has changed since last fall, and those changes matter.

From November 2025 to the present, many operations have adjusted original plans. That is normal. Weather conditions, economics, and agronomic considerations often force changes at planting, and those decisions are made with the best information available at the time. Not every change of plan adds cost to the budget. Still, every adjustment affects the actual 2026 cost of production.

Cost of production is never final until the combine leaves the field. Until then, it remains only a snapshot in time. Recalculating costs after planting provides an opportunity to replace estimates with actual numbers for inputs used so far in 2026.  The updated information can be directly used to execute the remainder of the grain marketing plan.

Consider the decisions that may have changed from planning season to planting season: seeding rates, fertilizer rates, nitrogen source, herbicide or insecticide programs, additional field passes, higher fuel use, or added custom hire. These changes to variable costs are important to revisit.  For example, a planting delay causes the soybean seeding rate to increase from 160,000 to 200,000 seeds per acre, and the realistic yield decreases from 57 to 45 bushels per acre.  The seed costs 25% or approximately $0.39 per bushel for the adjusted yield estimate.

Nitrogen fertilizer has been one of the biggest wild cards. Compared with other fertilizers, nitrogen prices have experienced some of the largest increases since fall 2025. Data shows UAN and anhydrous ammonia prices increasing 25% or more between October 2025 and April 2026. Re‑calculating cost of production allows adjustments for the actual nitrogen rate and source used, along with a blended price reflecting both prepaid and in‑season purchases.

Fixed costs in an enterprise budget tend to remain more consistent from fall 2025 to spring 2026, but even those can change due to refinancing interest rates, land purchases, or lease renegotiations.

The grain marketing plan should be a reason for updating the numbers. Many producers have only partially executed pre‑harvest sales. Pre‑harvest marketing takes advantage of grain price seasonality — historically, grain prices are higher in the spring and early summer roughly 70% of the time compared to grain prices at harvest. However, sound marketing plans do not price 100% of expected production ahead of time. Leaving some bushels unpriced after planting helps manage the risk of a short crop.

By recalculating cost of production after planting and monitoring crop development, additional marketing decisions can be made with greater confidence. Knowing the updated 2026 cost of production provides clearer guidance when evaluating whether current prices cover costs for the remaining bushels.

Cost of production can be calculated on a per‑acre or per‑bushel basis. Because final 2026 yields remain uncertain, calculating cost on a per‑acre basis often makes sense for the remainder of the growing season. Pairing that information with realistic yield estimates based on current growing conditions helps estimate a per‑bushel price for remaining pre‑harvest sales and post‑harvest marketing plans.

After planting, updating the cost of production provides an opportunity to review the accounting system and verify that expenses are accurately allocated to each crop. An accurate accounting system at this stage supports informed decision-making, simplifies future cost-of-production calculations, and reassures the farm manager that recordkeeping is current and prepared for tax season.

Updating cost of production now does not change what has already been spent, but it improves decision‑making for the rest of the season. The grain marketing plan is not a static document but rather a decision-making tool that works with the best available information.  In a year with shifting input costs and uncertain markets, better numbers support better outcomes.

Consider enrolling into the OSU Extension Basics of Grain Marketing online course during the Summer session with open enrollment beginning June 1. Contact go.osu.edu/grainmarketing, email Wm. Bruce Clevenger clevenger.10@osu.edu.