Make a plot of my corn yield history to see if there's a mea

Here's your farm-wide corn yield history — acre-weighted average per season, with the field spread (min–max) shaded and a fitted trend line.

Acre-weighted yield Trend (+3.2 bu/ac/yr, not significant) Field range (min–max) Thin acreage (low confidence)

Short answer: there's a slight upward drift, but it's not a meaningful trend — the year-to-year weather swings are far bigger than any underlying gain.

The numbers:

Trend slope is +3.2 bu/ac per year, which sounds like steady genetic/management gain.

But R² is only 0.19 and p ≈ 0.16, so it fails a significance test. Dropping the three thin-acreage years (2015, 2017, 2019 — hollow markers, only 380–760 acres each) barely changes it.

The residual scatter around the trend is ±23 bu/ac — bigger than a decade's worth of the drift. That's the weather talking: 2014 and 2022 cratered near 150, while 2021 and 2024 topped 218.

So I wouldn't hang a decision on the trend line. If anything's real, it's a modest few-bushel-a-year improvement consistent with better genetics, but you'd need more years — or a way to strip out weather — to prove it. The more honest read of your history is that a good-vs-bad weather year is worth ~70 bu/ac to you, which dwarfs the slope.

If you want to actually see whether your management is improving underneath the weather noise, the better move is to detrend each year against a regional benchmark or model out the weather (planting-window heat, pollination stress, June–July rain) and look at the residual. Want me to pull that together?

Line chart of acre-weighted farm corn yield by season, 2014 to 2025, with the field-level min-max range shaded and a fitted trend line. Yields swing widely year to year with a slight upward drift that is not statistically significant.