These farmers do not cultivate their land, they are defending it.
If the marked outline fence will be built, Palestinians will not have access to their land. The settlers marked the future fence over the road that enables the entry to the land owned by Palestinians. By doing so they are annexing not only the road but the valley's lands also, that is because the landowners will not be able to cultivate their land for some time. and then it might became a state land. After making it a state land it will be given to the settlement.
So what you see here is farmers pulling off the marks to a future fence and covering the holes that the fence poles might be put in.