A common theme among my Rose Scholars experiences seems to be that, from garlic to palm oil to grape vines to flowers in the botanical gardens, I don’t know anything about plants.  I had heard of hydroponics and I knew vaguely what the idea was, but I had no clue how it worked or what a system might look like.  So, I was thrilled to be able to attend Erica Hernandez’ talk where she outlined the major different kinds of hydroponic systems, explained how they work, addressed their pros and cons, and talked about the major advantages and challenge with hydroponics in general.

I did have one major question that I couldn’t quite put my finger on during the talk:  I know it is possible to drown plants.  I know this because I killed three successive succulents last year with overenthusiastic watering.  If too high a moisture content in soil can be enough to murder a plant, then how is it possible to grow a plant just water?  Are there only certain plants that can be grown hydroponically?  Is it just impossible to drown lettuce?

According to the internet, the difference is the oxygen exposure of the roots.  Plants need to take in oxygen through their roots in addition to their leaves, and in soil, they are exposed to plenty of small pockets of air.  If you overwater, these pockets become waterlogged with stagnant water.  The plant doesn’t drown so much as suffocate.  In a hydroponics system though, the water is aerated and constantly refreshed so that the plant can take oxygen from the water.

I’ve heard a whole lot of talk about hydroponics with regard to the looming global food crisis and environmental crisis.  Hydroponics could represent the future of human food production for an exploding population, in that it could be used in establishing indoor farms to grow crops without worrying about space or transportation.  It was also pointed out in the talk that hydroponics operations can run year-round, as the plants are sheltered from cold and bad weather in a carefully temperature-controlled indoors facility.  Many of the more passive systems also require very little labor.  So why are we not growing all of our food with urban hydroponics programs already?

The sticking point, or at least one of them, is apparently the same as with many futuristic solutions: energy.  Careful temperature and environment control mean that it’s difficult for large-scale hydroponics systems to be energy efficient.  This makes them neither cost effective nor environmentally friendly.  There is also the issue of light — you can light a smaller setup with natural sunlight, but this isn’t possible for stacked vertical farming systems (as I’ve heard touted as a solution to saving land space and growing in cities).  In that kind of system, you would have to use artificial light, which only makes the operation even more energy-intensive.  In fact, even if a farm isn’t hydroponic, lighting and environment control would be a problem for any indoor farming venture.  It looks like for now at least, we’ll have to look elsewhere for viable solutions to food production issues.  However, I hope I’ll be around to see what the food production landscape looks like in 50 years, and what kind of role hydroponics plays.