Historical Accuracy of Profarmer Crop Tour

Profarmer Crop Tour – History of Results verses National Agriculture Statistics Service

Each August, Profarmer goes into the major corn and soybean producing states and survey’s fields and develops an estimate of what yields will be.

Methodology - Corn

Crop scouts enter the field beyond the end rows and they recommend walking 35 paces past the end rows. They measure the row width and hook a 30' length of rope on a corn stalk. Next, scouts count the number of ears in two rows along the rope, and pull the 5th, 8th and 11th ears from one of the rows.
 
The scouts husk the ears, measure the length of cob and count the number of kernels rows around.  An average of the number of earns in the two rows is calculated.  Then an average of the grain length is taken of the 3 cobs pulled and an average of the kernel rows.

They the scouts plug it into the formula:

Ear count (X) x grain length (Y) x kernel rows (Z) = 5460/row width (30') = ABC bushels per acre.
 
Methodology - Soybeans

Crop scouts enter the field, get past the field's end rows and use a measuring tape to determine row width and define a 3' section of a row. They count all of the plants in the row and then pull three random plants from it.

Then scouts count pods on each plant and figure an average pod-per-plant count. Then scouts plug their numbers into this formula (I inserted numbers for this example):

Number of plants in 3' (X) x Average number of pods per plant (Y) = Pods in 3' (Z) x 36 (makes it a square) = ABC/row spacing (15) = 1176 pods in a 3' by 3' square.

All above methodology is sourced from https://www.dtnpf.com/agriculture/ag/blogs/market-matters-blog/blog-post/2013/08/19/crop-tour-arrives-yield-estimates
 
Historically accuracy of the Profarmer tour

Based on history from 2003, the Profarmer tour is very accurate in predicting  both the September National Agriculture Statistics Service (NASS) yield estimate and the NASS Final yield estimate (released in January of the following year).

On average, the corn estimate is off by 0.31 bushels when compared to the September NASS yield estimate and is off by 2.03 bushels when compared to the Final Year-end NASS yield estimate.

On average, the soybean estimate is off by 0.27 bushels when compared to the September NASS yield estimate and is off by 0.99 bushels when compared to the Final Year-end NASS yield estimate.
 
The data from each Yield Tour is below;