dpb writes:

If had the time, it would be interesting to try to actually delve into
the data itself, but it's planting season and then harvest and then and
and then and and...

Hey, at least you're not walking the rows of soybeans with a cornknife
cutting lamb's quarters and ragweed. Oh my aching back.

My grandfather refused to use herbicides, and when the beans got
tall enough, the cultivator on the Farmall B was no longer useful,
so the grandkids earned a bit of spending money.

He also was using a binder and threshing machine until the late 70's,
hot, sweaty, dusty work - particularly baling up the pile of straw.