Hydroponics is a method of growing plants without soil using water, an added nutrient solution, and a special growing medium such as coconut coir, perlite, or limestone gravel. Hydroponics is a great opportunity to help transform our food system into a much more sustainable and localized one. There are many advantages to hydroponic growing systems compared to conventional farming systems.
Due to climate change, with its predicted impacts of increased erratic and potentially destructive weather patterns, floods, and droughts, it may become increasingly challenging to grow crops using traditional methods of growing outdoors on expansive farmland. Hydroponics offers a way to work around many of those negative climate change impacts by growing food within a controlled environment which is often indoors.
In fact, a renaissance of growing hydroponic farms indoors has already begun, with indoor hydroponic farms in urban areas becoming more and more common throughout the world, including under the streets of London and in “plant factories” in Japan.
Hydroponic indoor growing is one way to help localize food systems in cities, where food is typically imported into cities long distances from the countryside or from other countries. A possible future of many cities is that urban vertical farms will dot the typical urban landscape among all of the other buildings. This would be a great way to help meet the challenges of a growing global population that is increasingly urban[sc:1]. Hydroponics could also provide an option for growing food in developing countries, helping to reduce world hunger[sc:2].
Growing more food locally through hydroponics helps to reduce fossil fuel use, since fossil fuels aren’t necessarily needed for these systems if the electricity that they use is sourced from wind or solar power with a commercial battery to store excess renewable energy for when it is needed. These systems also produce food locally, which eliminates much of the energy that is required to transport it from far away. With reduced fossil fuels required for the food system, we would also decrease our production of carbon emissions. Currently, agriculture is a large producer of greenhouse gases[sc:3].
Hydroponics is a good method of growing food where arable land is scarce, since food can be grown much more densely using a fraction of the land that is required to grow crops traditionally on large expanses of farmland[sc:4]. Hydroponics also allows for the growth of food year round in any climate, which is much more challenging to do in more temperate climates using traditional farming methods outdoors.
If hydroponics were applied worldwide and used as a major part of local agricultural systems, we could perhaps let some of the current farmland that is used today revert back to natural landscapes, increasing forests, prairie land, and other natural ecosystems that could help to sequester carbon dioxide and produce oxygen.
Another great thing about hydroponic systems is that they are scalable. They can be built as large commercial farming systems to supply food to local populations, but also could be used on a smaller scale by restaurants, hospitals, churches, grocery stores, daycare centers, and even in homes to produce food sustainably without worrying about erratic weather and unpredictable climate conditions.
What about energy and water requirements?
It is true that in general, hydroponics systems can require a lot of electricity to run, especially indoor systems that rely on fluorescent lighting. However, using LED lights and thick insulation on buildings that house the hydroponics systems reduces energy requirements significantly[sc:5]. Also, by sourcing energy from solar and/or wind power, combined with an on site battery storage system, the energy used by these systems can allow them to go entirely off-grid and have increased resilience in case a power outage occurs.
It is estimated that hydroponics uses 60-90% less water than conventional growing methods, due to the high rate of water loss from the soil through evaporation during traditional farming[sc:6].
Hydroponic systems can also be combined with special fish tanks to make them into aquaponics systems that produce edible fish like tilapia as well as vegetables and other crops.
What plants can be grown with hydroponics?
Almost any type of plant can be grown through hydroponics, including a large variety of flowers, vegetables, herbs, and even trees like citrus trees and cherry trees. The possibilities are almost endless with hydroponics.