If it seems like “hydroponic systems” are everywhere, that’s because they are. Hydroponic farming is one efficient way to grow fruits and vegetables in small spaces without the use of soil. Instead of dirt, plants grow down into water, to which farmers have added the necessary nutrients for plant growth. These are then absorbed, along with water, through a plant’s roots. Light is provided either by the sun or specially designed grow lights, with many sustainable systems powered by renewable energy sources. Aquaponic farming incorporates fish into the soil-less system, using the closed-loop nutrient cycle from fish digestion to their advantage. Some systems even feed nutrients to plants through the air! From water-less deserts to the sun-less underground, soil-less farming is offering new possibilities to feed an increasingly urban, growing global population in a more Earth-friendly way.
With consumers increasingly conscious of their environmental impact, many stores have realized that going green is good for business. Big-box store Target began a series of trials in spring 2017 in which vertical, hydroponic gardens were installed in various Target locations to provide customers with the freshest possible produce. In collaboration with MIT Media Lab and Ideo, Target designed a system that is capable of growing leafy greens and herbs with minimal water usage. The company hopes to someday branch out into other crops, such as potatoes, zucchini and beets. MIT may even offer Target use of rare heirloom tomato seeds for its project. Meanwhile, IKEA has teamed up with Denmark-based SPACE10 to design high-tech hydroponics systems in-stores and in homes.
In preparation for a future dominated by climate change, in which oil becomes a lesser part of the world’s energy diet, Saudi Arabia has taken several major steps to build a more sustainable system in its challenging desert region. One such move is the rethinking of many traditional farming practices, especially focused on reducing water usage. A farm in the town of Jeddah uses neither water nor soil, rooting plants in mid-air while providing their nutrients through a mist. Designed by AeroFarms, the system is the first aeroponic farm in the Middle East and hopes to someday acquire all its water needs through capturing humidity in the air.
If a desert farm chooses to go hydroponic, there are ways to grow without draining freshwater supplies. In arid South Australia, SunDrops Farms grows 15% of the country’s tomato crop through a solar-powered hydroponic system. To eliminate the use of precious freshwater, SunDrops sources its water from the nearby saltwater gulf, which is then desalinated through the reflected heat of the sun.
As the global population becomes more urban, cities are investing in more local food production systems that offer economic development opportunities and reduce a city’s carbon footprint. In a warehouse on the Near East Side of Indianapolis, Farm 360 are growing vegetables on a hydroponic system that is exclusively powered by renewable energy and uses 90 percent less water than traditional farming methods. The harvest is sold in local grocery stores while the farm supports dozens of living-wage jobs to residents of the neighborhood.
In even the most isolated urban areas, soil-less farming finds a home. With its ability to receive vital supplies and support a functioning economy severely restricted by the Israeli blockade, Gaza has stepped out onto the rooftops to grow its own food. Beginning in 2010, a United Nations-funded urban agriculture program equipped over 200 female-headed households with fish tanks, equipment, and supplies to build and maintain an aquaponics growing system. This initial spark has encouraged others to create their own and to teach others of this valuable skill.
4. The Underground
Farming without soil can often take place beneath the soil. In Paris, Cycloponics runs La Caverne, a unique urban farm that grows mushrooms and vegetables in an underground, formerly abandoned parking garage. The farm’s hydroponics system uses special grow lights to ensure the vegetables have what they need to survive. The mushrooms grow in a special medium and, through their respiration, provide valuable CO2 for the plants to thrive. La Caverne may have found inspiration from Growing Underground, London’s first underground farm. On 2.5 acres of unused World War II-era tunnels, Growing Underground produces pea shoots, several varieties of radish, mustard, cilantro, Red Amaranth, celery, parsley, and arugula.
Honorable mention: shipping container farms. Although these may be mobilized on the surface, they may as well be underground due to the closed roof of most shipping containers. The solar-powered hydroponicsLA-based Local Roots can grow the same amount of vegetables, at cost parity, with 99 percent less water than traditional farming.
5. On the Water
Some soil-less growing operations take it a step further, leaving the ground behind entirely and opting for a farm floating on water. Barcelona-based design group Forward Thinking Architecture has proposed a progressive solution to the decreasing availability of arable land by creating floating, solar-powered farms. Using modules that measure 200 meters by 350 meters, Forward Thinking’s design allows for expansion and custom configuration of farms. Each module has three levels: a desalinization and aquaculture level at the bottom, then a hydroponic farming level, topped off by a level of solar panels and rainwater collection. The company estimates that each module would produce 8,152 tons of vegetables a year and 1,703 tons of fish annually.
Greenwave takes an alternative approach to soil-less, floating farming by combining the cultivation of shellfish and seaweed, both profitable crops that also help to clean the aquatic environment and absorb greenhouse gases. The farm requires little external input, pulls carbon dioxide from the air and water, and consumes excess nitrogen that could otherwise result in algal blooms and dead zones.