as a variation to that idea, collect a few used car/ute tyres, they will give them away from any tyre shop here.
lay the biggest one flat on the ground, plant your potatoes as you have done, and cover to the top of the tyre.
when the green shoot is standing proud by 2-3 inches, place another tyre over the top and fill with compost again.
stop about 3-4 tyres.
compare the quantity of crop from the area used between the tyres and your raised beds.