Potatoes grow well in sandy loam soils well endowed with organic matter with a soil pH slightly lower that most vegetables like, around 6.0. Too much Nitrogen can cause too much top growth and too little root growth where the tubers will be formed.

Here is a link that might be useful: Growing Potatoes

Is your soil sandy? They like lots of water and rich but not too rich soil. I am still getting what they want for fertilizer figured out. Because as you say there are differing opinions out there. Anyway I use compost. My soil is also high in P and K. I think watering well and keeping weeds down is most important. The best potatoes I ever grew were some extra seed pieces thrown into a hot compost pile!

Thanks for the info and the link!
My soil is actually pretty clay-ey, but toward loam. I've been doing the whole job by hand, but this year I bought a hiller-furrower that attaches to a rototiller, so I'm hoping it will be a lot easier.

COMPOST AND VOLCANIC ROCK DUST...SEEN ON YOUTUBE AND SHOWS VERY SUCCESSFUL CROP...HUGH POTATOES...WILL BE TRYING OUT THIS WAY...PROBABLY IN CONTAINERS...ADDING COMPOST/DUST AS VINE GROWS...ROY