Pick a Plot
Jul 21, 2008
Chore time for me isn't what it used to be when I was growing up on our eastern Iowa farm, but taking care of two horses in the morning before I head in for work gives me a little time to think about the day ahead. Each morning, stop at this spot to get a feeling for the "tone of the day" - and some attitude about agriculture and the markets.
I was thinking…
... it's time to start getting ready for this year's Pro Farmer Midwest Crop Tour!
First... some "housekeeping:" The Tour has two new sponsors this year, Pioneer and John Deere Risk Protection. We'll be making great use of our sponsors' agronomic and crop-assessment skills on both the eastern and western legs of the Tour in 2008 and we're very much looking forward to building new relationships with our new Tour sponsors!
Friday, I posted some pictures of a July 15 "fly-over" tour of central Iowa. After the last photo, I asked, "How is USDA going to assess the damage?"
A Chore Time reader rightfully asked how Pro Farmer is going to accurately estimate yields on this year's crops that are obviously full of holes. Well... we'll work as hard as possible to get the best read we can get on this year's corn and soybean crops. And, we won't change a thing in how we run the Tour. It will happen on the scheduled week and we'll determine plot location the same way we always have.
We always run the Tour the third full week of August. Yes, that means there's some movement on the starting date, but by doing it the third full week of August every year, we can make meaningful comparisons from one year to the next. It's part of the year-to-year consistency we strive for in the Pro Farmer Midwest Crop Tour.
Another part of that consistency is in the data we collect and the way we collect it. We build individual yield estimates from: Average ear population in two 30-foot rows; average grain length (average of three ears in inches); average number of kernel rows around the ear (average of three ears); and the row width in the field. The yield calculation is very simple: (Average ear population X average grain length X average kernel rows) / row width.
Example: 46 (average number of ears in two 30-foot rows) X 6.25 (average grain length in inches) X 15.3 (average kernel rows) / 30 (row width) = 146.625 bu. per acre.
How do we pick the sample ears? It's always the 5th, 8th, and the 11th ears from one of the rows in the 2-row plot. That means the three ears we use as samples could be the three best ears in the row, could be the three worst ears in the row, or could be three very representative ears from that row -- or any combination of good, bad and average. By pulling the 5th, 8th and 11th ears from the row, it removes any bias a crop scout might have when they're pulling the sample ears.
How do we pick the field we sample? Crop scouts travel in teams of three or four on a predetermined route. On the eastern leg of the Tour, we'll probably run 12 routes each day of the Tour. On the western leg, we'll probably run 8 routes a day. Each route is (obviously) different, although some routes will cross during the day. That allows the Tour to "spider web" from location to location, covering as much ground as possible. Each route stops every 15 to 25 miles (determined by how many total miles the route travels that day -- longer routes stretch out the stops to make sure they get everything covered, but they all take at least one sample from every county they travel through). So... when drivers get close to their "mile marker" that says it's time to take another sample, they start looking for the first available corn and soybean field. Where they stop along the field is up to the driver.
How do we pick where we sample in the field? First we get past the end-rows. That should get us outside of the higher-traffic areas around the head-rows and away from gate holes. In some cases, that means we go in 48 rows against the rows (you guys with 24-row planters that plant double head-rows are killing me!). Once we get past the end-rows, we go another 35 paces down the row. At that point, we hook our 30-foot ropes to a stalk and measure off our two 30-foot rows that make up our ear-counting plots.
As you can imagine, when we're standing at the edge of a corn field, it's very difficult to predict what kind of conditions we'll find 35 paces on the otherside of the end-rows. When we get there, it could be the absolute best spot in that field, or it could be bare dirt, or it could be a spot where the giant ragweed stands two foot taller than the tassels, or it could be the absolute average spot in that field.
No matter what we find at that location in the field, we pull the sample. If we come out with the three best ears in the field, that's what we use for the yield calculation. If we end up in a spot that has been drowned out and there are no ears to count (even if it's the only "dead" spot in the field), we write down a "zero yield" and go on to the next "scheduled" stop. Even if we climb through 48 rows of excellent corn, march 35 paces through 200-bu. corn and end up in the only 30-foot long, two-row wide drowned out spot in the field, we write down "zero yield."
Obviously, the field isn't a "zero yield" field, but spot from which we're collecting the sample is a zero yield. But, that's okay... we're not trying to peg the yield in each individual field.
I know -- then why take the sample, right. Well -- wrong. If we were trying to peg the yield of one individual yield, you wouldn't pull one sample. You'd do your best to randomly select, say, 10 spots in the one field, pull those 10 samples and average the results into one yield sample for the entire field.
Well... that's basically what we're doing on Crop Tour. The individual field results aren't that important. But, our goal is to pull more than 1,000 samples from "one" corn field that stretches from Ohio to Nebraska and Minnesota to southern Illinois. That's why pulling as many samples as possible in four days is absolutely critical to the accuracy of the yield calculations on a state-by-state basis. During the August 17-21 Tour, we'll release results on a state-by-state basis. The more samples we pull from the "one" corn field in each state, the better the odds of getting close to USDA's final yield estimate for that state. And, if we can get close on a state-by-state, we'll get close to the national average yield.
For more information or to register for the 2008 Pro Farmer Midwest Crop Tour sponsored by Pioneer and John Deere Risk Protection, drop me a note (click here), or give Shelley a call at 1-800-772-0023. Who can come on the Tour? ANYBODY. Seriously... until the scout count gets to the point that we don't feel comfortable in managing the crowd, anybody and everybody is invited to attend. We cover the $75 registration fee for Pro Farmer Members and everybody gets fed a meal during each evening meeting.
This is just the first "installment" of what will be several Chore Time updates discussing the Crop Tour before we hit the road in about a month. By the time we start the Tour, I'll have shared as many "secrets" as possible about the event.