The release of the National Corn Growers Yield Contest winners within the past couple weeks has sparked even more interest in going to the next yield level. The national winner topped 454 bushels per acre. Several others posted yields in the 300 and 400 bushel per acre range.
You need to understand that these are not whole farm averages, not even field acreages. They're contest entries. Some people devote a whole field to the effort, others narrow it down to a plot and do special things, many of them costing extra money, where they're trying to reach high yields. When the weather cooperated this year many of those special things worked and delivered big yields and high placing in the contest.
Most agronomists have thought the maximum corn could produce was 500 bushels per acre. That means that one farmer this year grew corn that was more than 90% to the top of the yield chart. He grew more than 90% of all the corn an acre of corn could ever produce.
That's if you still believe the upper barrier is 500 bushels per acre. Many people may no longer believe that's the case. As plant breeders select for plants that capture more sunlight and tolerate more stress, and which can be planted thicker to produce more ears, the yield cap may be higher than once thought, as long as water is not limiting.
Some believe a few more things must happen before farmers in general, and not just in yield contests, will be reaching over 300 bushels per acre. A change in row or plant spacing to get better utilization of sunlight is often part of the equation.
Equidistant spacing is thought to be ideal. Believe it or not, farmers decades ago who planted in check rows were often plan ting at equidistant spacing. They did it for different reasons and they didn't have the hybrids of today, so they certainly didn't produce 500 bushels per acre, but the idea of getting plants spaced evenly for light capture and use of oxygen – not just so they could be cultivated two different directions – may have been an idea ironically ahead of its time.
The spacing will be much narrower but equidistant spacing may be one of the methods more people use to attempt to continue producing huge corn yields when the weather cooperates.