While out hunting I noticed that cut fields were being disked, but only around the edges and in low areas, the rest of the field was let alone. I was just wondering what the purpose of this was.
I suspect (my observations) many farmers disk the low areas on all their adjacent property first and then come back and do the entire field if time/weather allows.
Like noted below these low areas will stay wet longer in the spring ... thus the entire field does not have to wait come spring if the field is not finished in the fall.
Around here they just do it so the wetlands don't catch snow so they are easier to plant in the spring. The round around the field I am really not sure of? Maybe 40 years ago when conventional farming was the thing it helped keep road ditch grasses and weeds from invading but now every thing get nuked with glyphosate. I think its just habit?! maybe?
The downside is it also brings salts to the surface. So overtime the crop ground could be too high in salts to support row crops. And they are killing their organic matter in the soil and increasing average soil temps in those areas.
Some guys are good enough to ditch with their tillage equipment too. The worked up areas between the wetlands could be just that. I have seen guys use a ripper between the wetlands as well to help drain.
The end-rows get driven on more, you turn on them, means more compaction. Low areas get compacted more due to the moisture. Guys are probably tilling areas they think are getting compacted.