"This year I am planting the potatoes at the peak and only covering them half way with dirt."
Am I understanding correctly, between this and the picture, that part of the potato is left sticking out of the dirt? You don't have to worry about animals eating them? Or does the hay serve as a dirt substitute for covering them up? Do you build up more of a hill around them later on?
Sorry for the confusion, the hay will serve as the soil and keep the plants covered, no additional soil. One concern could be exposure to the sun on the new potatoes if the hay breaks down quickly which will produce green spots on the potatoes. If I see it breaking down I will simple add more hay when the plants are young and they will grow right through it. We normally do not have issues with rodents eating the potatoes.