I did the same with chain link fence but used 3 pieces of 3/4 conduit wired to the front, back and center. Made a loop to fasten under my trailer ball, run a small piece of chain thru it twice (if you don't loop it twice it will slide around) and fastened to the fence ends. Keep it back a bit or it will try and climb your back tires. It usually has enough weight to cover seed, but you can add weight if you don't think it is covering enough. One nice thing, you can roll it up and carry it on your back rack.

Russ