Did you know there’s a more accurate way to predict corn yields than doing a drive by scan on the way to baseball at 80 km/hr (I may or may not have used the drive by method myself …) It’s not much harder than scouting from the road. A quick field check using plants/acre, kernels/cob, and bushel weight can give accurate estimates in minutes. Plus, a reasonably accurate yield estimate helps you feel more confident about grain contracts, storage, and financial forecasting.
1. Calculate plant stand for 1/1000th of an acre
The first step in estimating corn yields is calculating the plant stand or counting the number of ears in 1/1000th of an acre. This is done by dividing 522.72 by the row width. In a 30-inch row the 1/1000th of an acre equivalent is 17.5 ft of row. If a corn field is planted in 30” rows and you count 29 plants in 17.5 ft, 29 is the first number in the formula.
2. Determine number of kernels per cob
The next step is to calculate the number of kernels/cob. Do this by multiplying the number of rows of kernels by the number of kernels in one row. To avoid bias, you need a field average, so use ears from the third, ninth and 15th plants. Determine the number of kernels/cob, add them together, then divide by the number of samples to get the average. (See the example)
3. Multiply average kernels by number of plants
Take the average number of kernels per plant and multiple it by the number of plants per 1/1000th acre.
4. Divide by bushel
The final step for estimating corn yields, now that we know the amount of kernels per 1/1000th acre, is dividing that number (in thousands) by the number of corn seeds it takes to produce a bushel. Each corn hybrid ranges in kernel weight, and therefore the amount of seeds/bushel can change based on the hybrid. Some older corn genetics would take 90,000 seeds to produce a bushel of corn, but for some of the newer hybrids, it takes only 75,000-85,000 seeds.
Next time – maybe the day after the ballgame – give this technique a try and look forward to seeing how close your estimate comes to what you actually pull off the field.