Saying you're going to check seed depth every time you move to a new field or hit a major difference in soil type is one thing. Taking the time to do it can be another, especially as it gets later in the season and you begin pushing to get done. But time spent checking seed depth to get it right can have a huge payback per hour.
Recently, one farmer planted several fields in an area where the latest glacier didn't hit. Then he moved two miles away to where the last glacier did cover the land thousands of years ago. The topography isn't all that much different, except there are more trees and rolling spots where the latest glacier didn't go. But the soils are markedly different. The older soil type, not affected by the newest glacier, has more clay and tends to stay wetter.
While it was drier for planting last week than at any time during planting seasons in the past three years, those fields of older soil still contained more moisture than the field of a different soil type a couple miles away. All the fields were no-till corn stalks. The difference showed up in how dry and 'hard' the soils were on top compared to one another.
Boil it down and what it means is that the planter had to be adjusted a half-notch lower to put seed deeper in the field where the soil was drier on top and harder overall. Keeping the same setting could have left some seed too close to the surface.
Say failure to stop and check and make the change leads to a modest 3 bushel per acre reduction in corn yield because the stand isn't as uniform, and there are fewer plants per acre. At $3 per bushel, that's $9 per acre, or $900 for a hundred acres. If you ran 100 acres without checking and it costs you $900, that means the 30 minutes spent checking and adjusting was worth $1,800 per hour!
Is this an extreme example? Probably not. A 3 bushel change is about 2%. Even if corn seed is placed at uneven depths and emerges several days apart, some of the plants will act as weeds, competing for nutrients, but being shaded out in the end, not producing an ear. Barren stalks don't add to the bottom line.
Time spent with the tractor stopped can be big payback time if you're using it correctly.