If you find old records showing your grandpa produced 40-bushel-per-acre corn in the 1920s, don’t assume he was a poor farmer. The average U.S. corn yield from 1866 — the first year statistics were kept — until 1936 stayed constant at about 26 bushels per acre.
Bob Nielsen, a Purdue University Extension corn specialist, uncovered several interesting facts while reviewing historical corn yield. Here are seven of them:
Fact 1. If corn yield increases stay on trend, averaging 1.9 bushels per acre per year, the average U.S. corn yield could reach 201 bushels per acre by the 2032-33 marketing year.
Fact 2. Only two shifts in the shape of the trend line have occurred — in 1936, when it jumped to 0.8 bushel per acre per year, and in 1955, when it increased to 1.9 bushels per acre per year.
Fact 3. Year-to-year departures from trend are caused primarily by year-to-year variability in growing conditions. The largest departure ever, 29%, occurred in the Great Drought of 1901.
Fact 4. The Drought of 2012 caused a 22% dip from the trend line. 2012, 1983 and 1988 rank among the nine largest negative deviations ever.
Fact 5. The largest plus deviation occurred in 1906, with yield 23% above normal.
Fact 6. Since 2002, yields have been at trend yield or above 13 times and below trend yield seven times.
Fact 7. Predictions by some seed industry experts that trend corn yield would reach 300 bushels per acre by 2030 thanks to biotechnology were misguided. However, without a major shift in the trend line, and if projections about future global population are correct, grain production could fall short.