That is a version of soil top planting; I have done it several times and yield was disappointing.
Now:
I cover my in-ground potatoes with a foot to sixteen inches of leaf mulch every summer; by the end of the summer there is from two to zero inches of leaves left.
You will continually be covering the plants all summer or you will have green potatoes.
I would broadcast a general fertilizer over the field once as soon as you can, or take soluble fertilizer and soak each plant once as leaves suck minerals out of the soil.
You will find rain is more of a pain in the arse with that method you used than an ally if it rains too often.
It will be a learning experience for you. (I used straw for mine which does not rot away quickly.)
