Putting a Wrap on Crop Tour

We’ve had a week to let the dust settle and reflect on what we found on the Farm Journal Midwest Crop Tour. More importantly, we’ve had a week to analyze data from the more than 3,100 corn and soybean samples scouts helped us gather Aug. 21-24.

It’s an open-minded, fact-finding mission
The goal of Crop Tour is to get a strong, objective view of corn yield potential from one big corn field across the Corn Belt during the third full week of August. Still, it’s nearly impossible to block out all of the data we’ve gathered about the crop ahead of Tour. In fact, some of that data helps shape our opinion of crops outside the Tour areas.

Heading into this year’s Tour, we knew we would find a lot of variability in this year’s crops. We also knew we would, in general, find crops that were less mature than normal. Heavy spring rainfall across large areas of the eastern Corn Belt forced fields to be replanted — some multiple times. After the heavy spring rains, some areas turned very dry.

Meanwhile, areas of the western Corn Belt dealt with increasing drought stress through summer. As a result, we found even more variability on Tour than we anticipated. There was also high variance in yields and crop maturity, sometimes within individual fields.

Good, but not great corn crop due to extreme variability
While the purpose of Tour isn’t to prove or disprove USDA’s Aug. 1 estimate, the question ahead of Tour was whether we would find the same yield potential as USDA did in its August survey work. Our data showed the 2017 corn crop is a good crop, but not as strong as last year’s record due to the extreme variability. Because of the variability and immaturity, we measured more potential than actual yields compared to the past couple years. Just how much of the yield potential we measured this year will be realized when harvest rolls around is uncertain.

Tour data showed total ear counts on all 1,559 corn samples collected down 0.2% from last year at 96.50. A lower ear count was expected after the rough spring led to some emergence issues. It’s also consistent with what USDA found in its August survey work.

Despite all of the talk about tipback this year, we found more grain length in Tour samples than we did last year. Average grain length at 6.74 inches was up 0.1% from what we measured in 2016. However, we measured a much less mature crop, which raises the question of how much of the grain length will be maintained into harvest. Some will likely be lost.

Kernel rows at 16.00 were down 1.0%, while average row width was virtually unchanged at 29.78 inches.

The average of all samples is our best number
As we’ve detailed in the past, we have two corn yield calculations that use the same raw data (ear counts, grain inches, kernel rows and row spacing). We report the results of the standard calculation during Crop Tour and in our final analysis because, over time, it has proven to be more accurate.

The second calculation attempts to adjust kernel size based on the number of kernel rows around the ear. (The higher the number of kernel rows, the smaller the kernel size is the assumption.)

The standard calculated yield from all Tour samples was 174.99 bu. per acre. The average from the adjusted yield calculation came in at 159.27 bu. per acre. The simple average of those two averages is 167.1 bu. per acre. The Pro Farmer yield estimate is the average of the two calculations. In a year with so much variability, we believe the average number is most accurate. With a +/- 1% range, the Pro Farmer yield forecast is 165.4 bu. per acre to 168.8 bu. per acre.

Breaking down Tour corn samples by yield
Of the 1,559 corn samples we pulled, 714 (45.8%) were 174.99 bu. (the average of the standard yield calculation) or less, while 845 (54.2%) were above that level. We had one zero-yield sample this year and only one that was above 300 bu. per acre.

Because there were more samples pulled above the midpoint of our standard calculation, we could see the national average corn yield push toward the upper end of our +/- 1% range at 168.8 bu. per acre. But again, we measured more yield potential instead of actual yield than the past couple years. We don’t anticipate all of the measured yield potential will be maintained into harvest, so we used the simple average of our two Crop Tour yield calculations.

August rains beneficial to soybeans
We say it every year… if our boots get muddy on Tour, which they did this year, soybeans are getting the late-season moisture they need to finish strong. Scouts found very few flowering fields, but soil moisture is there in many areas to plump up the beans within pods that we counted.

As you know, we don’t measure a soybean yield on Tour. The number of pods required to make a bushel of soybeans varies too much from state-to-state. Instead, we measure pod counts in a 3’X3’ square.

Pod counts were down from last year in every Tour state except Ohio. This year’s pod counts, based on a yield formula we’ve been working on for several years, suggest an average yield of 48.5 bu. per acre. With a +/- 2% range, the Pro Farmer yield forecast is 47.6 bu. per acre to 49.5 bu. per acre.