You do not need the ($125+ shipping) Agri Supply pipe layer attachment.
You can use a plastic electrical conduit 90 degree bend, with a short extension of straight conduit glued on one end.
To hold it on the shank, I will make 2 - 6" long threaded rod u-bolts, bent to fit around the shank plus the EMT, with the threads giving a good gripping surface on the plastic EMT.
Others have recommended this as an inexpensive alternative to buying the pipe laying attachment.
I will only be using this for 1600 ft. of 14Ga. dog wire.