I plant my seed potatoes under only a couple of inches of soil and then I pile straw on top. I am able to harvest my crop with just my hands, no fork needed.
I took a pic of the tubers after I pulled aside the straw because I was so impressed to see them laying there. I did not take a picture of the whole harvest but I probably tripled the amount that I planted and many of my potatoes were huge. These are Kennebec but the 2 red ones were a surprise so that must have come from a volunteer plant.
20180812_122732 by
Brownrexx, on Flickr