The Dekalb seed company recently shared a poster on Facebook depicting the top corn yields of 1940 and it got the gears turning in my head. For many decades, corn growers at the local, state and national level have competed in yield contests to see who can grow the most corn per acre. Bragging rights are at stake (and sometimes cash and prizes), and the 1940 yield contest winner for my home state of Indiana harvested 94.81 bushels per acre.
What about that clicks in my ag-nerd brain? The fact that in 2012, hopefully the worst drought of my farming career, saw our farm garner an average corn yield of 94.7 bushels per acre. For all intents and purposes, that's equal to the best of the best in my great grandfather’s day.
The poster shows a 102.38 bushel average for contestants over 12 states. The U.S. averaged about 123 bushels per acre following the horrendous drought of 2012. By those numbers, today’s worst is better than yesteryear’s top dogs.
But back in 1932 this country planted 113 million acres. The average yield that year was 26.5 according to NCGA. That's nearly 100 bushels less than last year’s crop which again was the worst drought since 1988, and maybe since the Dust Bowl era. Total 2012 corn production quintupled all 1932 could muster. So what has changed?
Plants on the rise
But plant breeding has a great deal of impact on the yields we can produce today. Two or three generations ago corn literally couldn’t compete with itself and it was planted at populations under 10,000 plants per acre.
As we've continued to breed corn plants over time, we continue to select for plants that can better handle environmental stresses. If you have more plants in the same space, they tap into the same water and sunlight.
Look at "old" corn plants, and you'll see that the leaves are droopy. Modern plants have leaves that are upright and can capture more sunlight. Sunlight is a big deal, and closing your canopy as soon as possible is important. Weeds can steal sun just like water and nutrients.
As the ability to handle stresses such as lack of water or sunlight improves it stand to reason that higher populations can be planted. The silver lining of 2012 is that the stress of the drought will show strong data for varieties that performed relatively well. You can be sure seed companies and breeders will be hanging on to those genetics.
Today on my farm, we average about 32,000 plants on an acre. The size of the ear may change, but the sheer volume of plants we can get planted, compared to days past, translates to many more ears at harvest. Anyone with farm experience will tell you about the endless variables that go into harvesting a good crop, but the ability to plant large numbers of corn plants is certainly important.
Top of the crop
So where are corn yield contest participants sitting today? NCGA has posted results of their 2012 winners across the nation in several classes. Winning yields in my state pushed 300 bushels per acre. National winners in irrigated classes were knocking on the door of 400 bushels in one of the toughest plant stress years in history! Yields were nearly four times greater than 1940’s best. Of course this is not only a trend we see in corn, but in all facets of American agriculture.
Want to know more about where your corn, beef and other foods are coming from? Here's your chance. Brian Scott and plenty of other farmers are listening, so post your question in the comments below and we'll do our best to get you an answer.