wastewater treatment

O'Neill made the same sort of statements about what plants needed throughout
The High Frontier. From what I know of organic gardening, all I can say is
that as a plant biologist, O'Neill was a darn good physicist. It's is
patently and provably wrong that all plants need is water, CO2, nitrogen in
some primitive form and an inert substrate to thrive. At the very least
they need a complex of inorganic and organic components, and of course the
more complex these inputs are, and the closer they are to what the plant
needs, the less energy it has to expend to modify them, and the more energy
it can put into growth and food production. It's the bontannical equivalent
of saying that we need only populate an Island Three with female nurse
midwives, frozen spunk and an encyclopedia, and they'll produce what they
need to have a functioning society. It MIGHT work, but you'd lose a lot of
time while they figured it out, and nobody would have much fun. And even
then the analogy breaks down, because within a generation or two the people
would have adapted and found short cuts, where plants aren't smart enough to
do that.