I haven’t done anything quite like that but it is an interesting question. What are you growing? How tall and wide does it have to be? How many rows and how long? How much room will you have between rows so you and the chickens can get through?
Let’s see. You probably want something inexpensive, does it need to be reusable? Are you planning on storing it over the winter? Some stuff can be a real pain to store. I think the more reusable you make it the more expensive it will get. Chicken wire might work as long as the holes are small enough the chickens can’t stick their heads through it unless you keep it well away from the plants. It will need to be removable so you can mulch, weed, and harvest your crops. It needs to stand up to wind. It needs to let sunshine and rain through yet allow excess moisture to evaporate so you don’t cause mold, mildew, or other diseases. You don’t want the chickens to be able to go under it so it needs to be really close to the ground. If your plants start to grow through the mesh it will be a pain to remove it.
I can see many different things working, each with their own advantages and disadvantages. I’d consider bird netting or deer netting to cut costs, but that stuff can be a pain to work with. It gets tangled up so easily and will snag on its own imagination. If you can find PVC long enough and flexible enough to bend in the shape you want that can work but you’ll have to anchor the ends someway so they don’t spread apart or fall over. It can be done.
I’d be tempted to drive T-posts and use bird or deer netting over those. I’d tie the netting to them with string that I could easily remove (cut if necessary) so I could get to the crop to work. If you have a wood lot with straight suitable branches or sprouts you could maybe use those but that netting will snag on those something awful.
Jut some thoughts off the top of my head. Maybe it will spark an idea for something that might work for you. If you have raised beds or your rows are spread out enough this sounds pretty good but in my garden these would be so close together I would not have room to work between rows.