From the Rows - Chip Flory - Crop Tour Kickoff
Tonight we gathered in Sioux Falls, South Dakota, and it looks like (unless the outlook changes big-time) tomorrow will be a much drier start to scouting than Day 1 last year. It'll be warm and windy, but we'll likely be dry.
We're running 10 routes again on the western leg of the Tour. These are the same 10 routes we've run for several years - that's part of the consistency of the Tour. We do not, however, preselect fields to sample. Field and plot selection are left up to the scout teams that stop every 15 to 20 miles on their route - that's part of the randomness of the Tour. Scouts travel in teams of 3 or 4 and the routes are scattered to cover as much ground as possible as quickly as possible.
Once a field has been selected, scouts will walk past the end rows, then go 35 paces into the main rows of the field before laying out two 30-foot plots. Scouts will count all the ears that will make grain in the two rows, and record the tally. Scouts will also pull three ears from each field; the 5th, 8th and 11th ear from one of the 30-foot rows. That's consistency and randomness in one step of the sampling process. By selecting the 5th, 8th and 11th ear from one row of the plot, we could end up with the three best ears in the row, the three worst ears, three very average ears from the row or any combination of good and not-so-good. That's an important part of the process because it removes any bias the scout might have.
On the sample ears, we measure the length of grain on each ear in inches... we don't measure bare cob or aborted kernels, just the length of viable kernels. We also count the number of kernel rows around each ear. Along with the row width in the field, the data driving the yield calculation is the average ear count, the average grain length and the average number of kernel rows around the ear. The yield calculation we use: (Average ear population in 30-foot of row TIMES the average grain length TIMES the average number of kernel rows) DIVIDED BY the row width in the field.
In soybean fields, scouts go to a "representative" spot in the field without cutting a path through the field. We then measure a 3-foot plot and count all the plants in the 3-foot plot. Three plants are then selected at random and we count all the pods that measure at least 1/4 inch on the three plants and calculate the average number of pods per plant. We then calculate the number of pods in the 3-foot plot by multiplying the average number of pods per plant by the number of plants in the 3-foot plot. To calculate the number of pods in a 3'X3' square, it's the number of pods in 3-foot TIMES 36 and DIVIDED BY the row space. This gives us the ability to compare soybean fields regardless of row width.
As tweets, reports and conversations start to flow from the Crop Tour, please keep in mind you're reading reports from 1 of the 10 western routes or 1 of the 12 eastern routes. What the other routes are seeing might, and very likely will, be different than what other routes are seeing. We will do our best to get the information out as soon as we can each evening, and waiting for the full results from each state is the safest way to get perspective from the Tour. If you're following the Tour on Twitter, just search for #pftour16.
Also, the Tour results should not be compared to USDA yield estimates in each state. We do things differently than does USDA, so the results should be expected to be different. Each night, Brian Grete, leader of the eastern leg of the Tour, and I will provide the perspective to allow you to compare this year's Tour results to last year's results and to the three-year average for each state. If you must compare it to the USDA data, do it on a percentage basis. Also each night, Tour consultants Mark Bernard (east) and Emily Carolan (west) will provide some perspective on agronomic issues observed by all routes.
The data you see from the Tour is "raw data" - that's what we've always released from the Tour. And since we've been doing this for a while (this is the 24th Pro Farmer Midwest Crop Tour), we've noticed some tendencies. Since 2001, the calculated corn yield for Ohio has been, on average, 1.9 bu. too low when compared to USDA's final estimate. That's an average - and, depending on the finish for the crop, there have been years when the Crop Tour results have been closer, and years when the Crop Tour calculated yield was further off than the 1.9 bu. average "miss."
In Indiana, the Crop Tour yield since 2001 has been, on average, 2.1 bu. too low.
In Illinois, the calculated Tour average since 2001 has been off by just 0.4 bu. per acre. However, don't just "assume" we'll have an "average" year - conditions change every year and each crop "finishes" differently. We do know, however, that the calculation works best on a more-mature crop.
In Iowa, the calculated Tour yield since 2001, has been 3.7 bu. below USDA's final yield estimate in the state. In South Dakota, the calculated Tour yield has been 5 bu. too high.
Now for a couple of "big misses." In Minnesota since 2001, the Crop Tour yield has been 11.5 bu. too high. That's because we pull the majority of samples from Crop Districts 7, 8 and 9 across the southern - higher-yielding - part of the state. We do pull some samples from Crop Districts 4 and 5, but not nearly enough to balance the southern part of the state.
In Nebraska since 2001, we've measured the corn crop 15.3 bu. too light on average. Nebraska is about 60% irrigated and 40% dryland corn. On Tour, we typically pull about 38% to 40% irrigated samples, resulting in a too-low calculated yield. In "good" crop years, that gap narrows because of stronger dryland yields.
I'll remind you of these historic variables each night - they're important to remember.
And don't look for a soybean yield estimate from the Crop Tour. The raw data we provide is the pods in a 3-foot by 3-foot square. In addition, we'll talk about the crop maturity index and the soil moisture index for each state on a nightly basis. And for perspective... the moisture index rating may be just as important as the pod counts!
I'll check in with you guys tomorrow night from Grand Island. We'll have the final results from South Dakota and will give you some perspectives on corn and soybean yield potential in northeastern Nebraska.
Follow #pftour16 Leaders Chip Flory and Brian Grete, as well as Consultants Mark Bernard and Emily Carolan on Twitter. Follow Julianne Johnston for official Tour results.
Additional Pro Farmer Midwest Crop Tour information is available on ProFarmer.com.
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