Ag Instructor Vic Martin: Agriculture and Averages

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Great Bend Tribune
Published November 10, 2019

 

First, the drought monitor is shows an expansion of the abnormally dry areas in Western and South Central Kansas. Second, harvest is making progress throughout the state and with any luck should be wrapping up shortly. Kansas is in much better shape than much of the Midwest. Much better shape in harvest progress. So far indications for Kansas are an average corn and soybean crop. Not fantastic overall but not bad either. Much of the grain sorghum crop, according to anecdotal source is overall good to excellent in the 90 to 120-bushel range. Not bin busting but certainly good. And moistures so far have been good thanks to the freezes. Wheat stands overall are good to excellent with a much better start than last year. Now onto today’s topic – Averages & why they aren’t very helpful for agriculture.

What is an average? Average may be defined as: “a number expressing the central or typical value in a set of data, in particular the mode, median, or (most commonly) the mean, which is calculated by dividing the sum of the values in the set by their number.” In English, an average is determined by adding up all the values for a given set of numbers and dividing by the number of values. For example, you have two days with the high of one day of 70 and a low of 50. Another day, the high is 90 and the low 30. The average temperature of both days is 60 but they are quite different days. One other example. There is a group of ten people. Eight have an income of $10,000 per year and one has an income of $120,000 per year. The average income for the group is $20,000. The eight making $10,000 and the one making $120,000 would both be unhappy with that average as it doesn’t reflect their income. Now, let’s move this concept to agriculture.

Until the advent of GPS and yield monitors, producers looked at the field average yield. They cut the crop, took it to the elevator, added up the scale tickets, and divided by the number of acres. Producers have known this doesn’t reflect the variation across a field. Some areas of a field would yield much less and some a great deal more. Before yield mapping, a field was normally treated as uniform and seeding rates, fertilizers, etc. were applied uniformly. This meant over fertilizing or seeding some parts and under fertilizing and seeding or watering others. The average wasn’t helpful. Today with GPS, yield monitors and grid sampling for soil properties, farmers can now address variation, optimize inputs and minimize costs. They can increase yields on the better parts of their fields, and not waste money on those parts that won’t respond.

One other important area where averages don’t help agriculture is weather, especially precipitation. If you have lived in this part of the world for any period of time, you know how variable precipitation patterns are. We can go from excessive drought for a portion of the year followed by excessive precipitation. If we look back at the end, the average for the year may be close to the long-term average. Looking at the actual data tells a different story.