How can plants like Scallions be regenerated and regrown indefinitely in just water without any of the minerals that would be present in soil?

Question

People have shown that you can regrow bulbs of scallions by submerging partially in water. I am aware plants only need sunlight, CO2, and water to produce energy, but I was also impression plants needed trace amounts of nitrogen and some minerals and metals to grow as well. Would scallions grown in just water be able to grow forever without any minerals? And by that logic wouldn’t these scallions also contain no minerals when eaten?

In: Biology

Answer 1

They cannot. There’s only so much a scallion can muster to keep its metabolism if not provided with sufficient K/P/N;

Answer 2

For example, just looking up mineral content of scallion:

Calcium 72mg, Iron 1.5mg, Magnesium 20mg, Phosphorus 37 mg, Potassium 276mg, Sodium 16mg, Zinc 0.4mg, Copper 0.1mg, Manganese 0.2mg, Selenium 0.6mg.

Also the compounds inside scallions that make them “spicy” are derived from Sulphur. If they’re only getting water, sun, and CO2, where is the Sulphur coming from?

Answer 3

Before your post is removed for being a straightforward question, I will say that you can’t indefinitely prolong the life of scallions this way. Eventually they’ll die, because they’re cut off from the minerals that they need to survive. You can really only do this trick once or twice.