The Matrix

[Occhidiangela]

From Ithil

Hydroponics, of course. 

For hydroponics to work, you need soil. Fertile soil needs constant re enrichment, per crop fertilization rotation and organic decay, or it slowly loses its yield ability. Zion is deep deep down in the earth. WHere are the animals and bugs and birds that contribute to the cycle, and more importantly, the plants not under cultivation? Where do the nitrates come from for the fertilizer? The soil gets no radiation from the sun, even though the lamps powered by thermal sources substitute somewhat.

Soil is not just ground up rock, it is a boundary covering over the rocks et al that is made up of a great many organic compounds that have decayed. The Earth's surface has been 'dead' and 'dark' for quite some time, the normal processes that make and break down soil, the soil that you put into a hydroponic system, strike me as missing a few elements down there in the bowels of the earth.

I can understand how they make air and scrub it, that technology has been with us on nuclear submarines for decades. It's the other wide variety of materials, the nitrates etc, that might be in all the wrong proportions.

The other point someone made above is that the protein rich diets needed to make large, well fed people is missing another key ingredient, animal proteins. If this system has been going on for quite a few years, I'd guess the people would over time shrink in stature due to dietary influences.

All that said, I suppose that the suspension of disbelief would have been better for me had the food looked like something not quite like what we are used to. And that is really a small detail, as some form of nourishment has to be assumed in order for people to survive and thrive and reproduce, otherwise the thesis of the story simply can't hold water.

Not looking to be disappointed, but that internal inconsistency was a small disappointment to me. What the folks live on and eat is important, to good science fiction. :)