Karl Treen wrote:
Hypothesis #1: Leaves are solar panels. If you bury the solar panels, there is less energy to make the tubers. While you may gain some potatoes growing off the stems, you may lose harvest weight because of the solar energy lost in the process.
Hypothesis #2: A plant can only commit a certain amount of energy to producing tubers. Leaving aside the solar collection issue, it is doubtful that a buried plant will produce more weight in potatoes, unless perhaps it is gaining significant nutrient from the mounded soil or mulch.
Hypothesis #3: The extra human energy, materials, and money spent creating complex potato systems is a total waste unless you need to grow potatoes on a balcony or rooftop and are doing it just for fun.