Yield per field, per crop
Which ground pays and what to plant where. Where a trustworthy yield number comes from, how to correct it so fields and years compare, and what tools are free.
The short version. One load, one field, weighed, with a moisture reading. A notebook, a scale, and a moisture tester beat an expensive app that gets fed guesses. If the combine already has a yield monitor, the maker's cloud account is free and does the field summaries for you. On a dairy, the fields that matter most are the forage fields, in dry-matter tons per acre.
Where the number comes from, most to least reliable
| # | Source | Use it for | Watch out |
|---|---|---|---|
| 1 | Certified scale ticket (elevator, co-op, truck scale) | The control total for the whole crop | Must be tied to a field. "Paid" bushels may already have shrink and dockage taken out. |
| 2 | Grain cart scale | Splitting production by field | Check it against a certified scale several times a season. |
| 3 | Combine yield monitor | Field totals and maps | Uncalibrated, it can be off 5 to 15%. Calibrate every crop, every season. |
| 4 | Bin, silo, or bunker measurement | Inventory cross-check | Density guesses cause big errors. |
| 5 | Wagon or truck counts | Last resort | "Full" is never the same twice. |
Six rules that make the records worth keeping
- One load, one field. Write the field on the ticket when the truck is loaded, not later. If a load must mix fields, split it by cart weight before unloading.
- Weigh, don't guess. A moisture tester and some kind of scale are the first purchases, before any software.
- Harvested acres, not FSA acres, not planted acres, go in the denominator.
- Correct everything to the same moisture before comparing fields or years.
- Never correct twice. If the elevator ticket already shows dry bushels, do not apply the formula again.
- Keep the originals. Scale tickets, monitor files, the notebook. Crop insurance reviewers want them, and they are the proof if two totals disagree.
Calculators
Everything runs on your phone. Nothing you type here is sent anywhere.
Standards: corn 15.5% and 56 lb; soybeans 13% and 60 lb; wheat 13.5% and 60 lb; oats 14% and 32 lb. Call the result "yield at 15.5%," not "dry yield." Grain at 15.5% still has water in it.
Dry hay. Weigh a few real bales. The baler's "1,200 lb" setting is not a weight. 100 bales × 1,200 lb × 0.85 dry matter = 51 DM tons.
If the combine has a yield monitor
- Calibrate with 4 to 6 loads spanning low to high grain flow, each 3,000 to 6,000 lb, weighed on a real scale. One load is not a calibration. Recalibrate for each crop, when moisture changes a lot (corn dropping from the mid-20s to the high teens), after any sensor or header change, and whenever a check load is off by more than 2%. (Ohio State, Purdue, Iowa State guidance.)
- Check the moisture sensor against a bench meter or the elevator's reading several times a season.
- Use the free cloud account that matches the combine. John Deere Operations Center is free and gives harvested acres, total bushels, average yield, and moisture per field, plus multi-year comparison. Case IH and New Holland have AFS Connect / FieldOps. Ag Leader has SMS (desktop, about $800 to $1,200) and AgFiniti. Get field names consistent before uploading, or "North 80" and "north 80" become two fields.
- Reconcile the monitor to the scale tickets with the calculator above, and note the factor.
Tools, cheapest to most expensive
| Tool | Rough cost | Notes |
|---|---|---|
| Load sheet + spreadsheet | $0 | A "Loads" sheet (one row per load) and a "Field Summary" sheet. Columns are on the templates page of the PDF. |
| Moisture tester | $300 to $1,000 grain; $450 to $900 forage (Koster) | First purchase. |
| John Deere Ops Center, CNH FieldOps | Free core | Free with the equipment. The best deal in farm software if you run that color. |
| Bushel Farm (formerly FarmLogs) | From $199/year | Field records, grain inventory, contracts. Closest simple record-keeper for a small grain farm. |
| Climate FieldView | From $99/year; Plus tier roughly $300 | Mixed-brand fleets, maps on an iPad. Needs the Drive hardware. |
| Ag Leader SMS Basic | About $800 to $1,200 once | Reads most brands' monitor files. Good durable archive. |
| Grain cart scale retrofit (Digi-Star/Topcon, Scale-Tec) | $4,000 to $10,000+ | Assigns weighed loads to fields. Not legal for trade. |
| Traction Ag, Conservis | $1,000 to $15,000+/year | Accounting tied to fields. For bigger or multi-entity farms. |
Prices are 2026 planning ranges. Confirm with dealers before buying.
If you hire custom harvesting: put the records in the deal. Ask for the monitor files, a per-field summary with harvested acres and average moisture, field-tagged load tickets, and copies of scale tickets within ten days of finishing each crop. "Field 12 made about 185" is not a record.
What the records are good for
- Which ground pays. Rank fields by yield relative to the farm average that year (field ÷ farm average × 100). Three years is a first pattern; five is when the ranking means something.
- Crop insurance APH. Reviewers accept scale tickets and settlement sheets as hard evidence, with load and yield-monitor records to split by unit. Records must show buyer, date, gross, tare, net, moisture, and field or unit. Keep them at least three years; ten is better.
- Landlord and lender reports. One page per field: acres, crop, variety, yield at standard moisture, five-year average, what went on it.
- Nutrient plans. Real yields give real removal numbers and real yield goals.
On a dairy: forage yield becomes days of feed
Feed is typically 50 to 60% of the cost of making milk, and most of it is grown at home. A dairy's most important field record is forage in dry-matter tons per acre, because that number is what turns into days of feed and, eventually, into income over feed cost.
Common mistakes
- Planted or FSA acres in the denominator.
- Calling settlement bushels "harvested" without checking shrink and dockage.
- Calibrating the monitor with one load, at full flow.
- Comparing forage on wet tons.
- One moisture sample for a whole field or day.
- Mixing fields in a truck with no load log.
- Nominal wagon capacity or bale weight instead of a real weight.
- Losing raw monitor files when the display changes.
- Field names that differ between family, the custom operator, FSA, and the agronomist.
Questions for your crop adviser or Extension office
Are our acres measured right? How should the scale or monitor be calibrated for this crop? How many moisture samples per field? What explains the weak fields? What's a fair local dry-matter yield benchmark?
Free resources
- Ohio State, Ohioline ANR-8: tips for calibrating grain yield monitors. ohioline.osu.edu/factsheet/anr-8
- Purdue, Corny News Network: "Yield monitor calibration: garbage in, garbage out." agry.purdue.edu/ext/corn
- Iowa State Ag Decision Maker: crop budgets, machinery costs, silage pricing. extension.iastate.edu/agdm
- Illinois farmdoc: crop budgets, FAST spreadsheets, crop insurance tools. farmdoc.illinois.edu
- Cornell Small Farms: how to establish crop production history for crop insurance. smallfarms.cornell.edu
- Penn State Extension: "Feed inventory for the dairy herd." extension.psu.edu
- USDA Web Soil Survey: soil maps by field. websoilsurvey.nrcs.usda.gov
Printable PDF with load-ticket and field templates Go to milk per cow →
Tell us what you think
How do you get a field's yield today: monitor, cart scale, elevator tickets, the notebook? What did we get wrong? What would help that isn't here?