At what cost for fertilizer, water, and labor? For potatoes, about 1 ton of (commercial) fertilizer would be required, and a lot of water (around 2,800m3 of wa

At what cost for fertilizer, water, and labor? For potatoes, about 1 ton of (commercial) fertilizer would be required, and a lot of water (around 2,800m3 of water), which is fine if you live in the mid-west with lots of rain, less fine in the desert portions of California.