I grow my potatoes completely in straw and the reason is to avoid scab which is a fungus and the spores live in the soil.
If you go completely with straw you need to keep it very deep to block out all of the light from the tubers as they develop or they will turn green.
Here is a pic to show you
DSC00880 by
Brownrexx, on Flickr
And here's the harvest
20170806_154413 by
Brownrexx, on Flickr