Factory Even

I published a new farmdoc daily article this week about the trend in the U.S. average corn yield. This is a key driver of overall agricultural productivity and has profound implications for several important policy issues. I concluded there is no compelling evidence that the rate of growth in corn trend yields in the U.S. has slowed in recent years.

The chart below shows that the U.S. average corn yield has been growing about two bushels per year since 1980. What is behind this monumental story of agricultural productivity? The most important is undoubtedly seed genetics, but other factors have also contributed such as improved seed protection, higher population, and improved weed and pest control. What I want to focus on in this post is something that does not get the attention that I think it deserves—improved planter technology.

I want to illustrate the point using my family’s farming operation back in Iowa. The picture below shows my Dad, Jim Irwin, planting corn in May 1971. His goal was to have “factory even” corn fields. What he meant by this was corn plants spaced apart as evenly as possible, the same height of plants across the field, and nice straight rows. He felt this was the way to maximize production given the corn hybrids available and gave him a competitive advantage compared to many other local farmers. Achieving “factory even” started with the planting operation, which he thought was by far the most important part of producing corn. This meant excellent seedbeds, planting in the best conditions, and paying obsessive attention to seed depth, population (seeds/foot), and spacing. My Mom, Pauline Irwin, was responsible for making sure that seed depth and placement were reasonable. But no matter how hard they tried, the planting technology available to them in the early 1970s had major limitations. The planter units bounced up and down through the field, creating uneven seed depth. The rotating “plates” that fed seeds into the furrow were notoriously inaccurate in terms of spacing. The planter was light and did not keep even pressure on the “shoes” that plowed the furrow. The list was long.

Now compare the 1970s planter to the planter unit shown below that is used by my family today to plant corn. It is a technological marvel that incorporates features that essentially automate the creation of “factory even” corn fields. The planter “flexes” through the field, keeps a uniform down pressure on the units, and seed depth and placement is amazingly consistent. Precision computer technology monitors every function in real-time. Late in his farming career, my Dad lamented that the newer planters were chipping away at his competitive advantage, as the new planters made it much easier for anyone to have “factory even” corn fields. The march of technology

I think there is a broader lesson here about agricultural productivity. The kind of technological improvements I have outlined here for planters has been repeated to varying degrees throughout Corn Belt agriculture in the last half century. With the onset of further technology revolutions like gene crisping, machine learning, and whatever else comes next, put me in the optimistic camp about the future of corn trend yields.

Laurence J. Norton Chair of Agricultural Marketing
University of Illinois at Urbana-Champaign