I have a small farm operation so here is my take.
1. On the line where he is CLEARLY overplanting onto your land I would go out there tomorrow and pound a post every 50-100 feet. You can slip either a rain gutter downspout over it or take some 3-4" white PVC pipe and and make some 3-4 foot chunks and then put a cap on them and slip them over the pipe so they are visible from 1/2 mile away. Not one damn reason for him to be on your side of the line there if its really that bad. I wouldn't give 2 shits if he had standing corn or beans there either. I would kill everything on my side of the line if I didn't want it there. That shit would not fly with me.
2. On the line where your trees are hanging into his field I can definitely see why he wants them knocked back. I think he is well within his right to remove limbs from your trees hanging into his field. You should have let him pile the crap on his side and burn it. Instead he might have thought he was doing what you wanted. Woods that encroach onto field just keep being more and more of a problem. The trees choke out a few rows of production, but more importantly they have a chance to do real damage to the equipment. He should have the right to farm right up to the property line. It is frustrating in the farming world to deal with other people's trees. I bet if you would keep the edge maintained he would have no problem staying on his side. As the tree limbs from your side grow out they can push the tractors, combines and planters 10-15 feet away from the boundary to safely farm their own ground.
I'd be talking to them sooner than later that's for damn sure.
That sounds like you're a pretty rational person, as are my neighbor farmers.
I wanted to do some edge feathering on my west line that's his crop rented property. I told him I just want access, when convenient, to drop some of my trees that way and drag them back. EEzy peezy, no problem, no pissing match.
Got a similar on the east side this year. That neighbor is going to tile his field and wanted to know how to the fence would be fine. I said right to the line, baby, as I want a lot of that water gone also. Although it will be tilled into the creek that dumps into and crosses my property. My feeling is it comes onto my property anyway andit goes into the creek anyway.
I love getting along with neighbors.