Let’s talk about urban farming. Many of us have heard about urban farming in the sense of rooftop or community gardens on the one hand, or tasted the results when enjoying lettuce from L.L. Urban or Coastal Plains Produce. Recently I learned that urban farming, also called vertical farming, is being done on a massive scale in locations around the globe. And while urban farming still includes personal and small to medium scale farms and projects, it now includes monoliths like Sky Greens in Singapore, a four story transparent building that rotates all four stories of plants by the windows using a giant pulley system. The even the US is home to large scale urban farming, like the 90,000 sq. ft. facility in Chicago. Described as looking like a Cosco put with plants instead of breakfast cereal, the facility houses pallets of hydroponically grown plants stacked six deep from floor to ceiling and lit by LED lights so the plants can grow 24/7 in a climate controlled environment. The downside: that’s a lot of lights.
Which brings me to a key point in the urban farming issue: not everyone whole-heartedly approves. There seems to be as many issues in discussion about large scale urban farming as there are varieties of urban farms. While issues of the environmental impact and efficiency are a big part of the discussion (and we’ll get to that), but one of the first issues I came across was light. Those in favor of urban farming either go to the sun or electricity for their light. With natural light comes a substantial reduction in required power, while using LEDs allows for 24/7 growth. Those opposed to the idea argue that natural lit urban farming can’t produce enough to serve as a substantial supplement to traditional farming because of having well-lit space, arguing that windows don’t provide enough light for the plants.
But the issue of light is just a subset of the larger efficiency and environmental issue. Proponents of using LEDs in indoor farming have stated that, while a large amount of energy is used, the big reduction in carbon footprint miles makes up for that. Others argue that it is still terribly inefficient, and if we produced the entire US vegetable crop using indoor urban farming, it would take half the power we produce in the US and create 1.3 billion metric tons of carbon emissions yearly. Those in favor argue that green energy could be used, while the opponents say that green energy would still be wasted when it could have been used to replace the energy we use in other ways. For example, one expert argued that to use solar power, there’s a sizable loss of energy at each stage of conversion, when in the end, the energy is turned back into light that the plants could have used for free if they were outside.
Another argument in favor is the water efficiency of hydroponic systems, which be collecting and reusing water, are 97% more water efficient than other growing methods. There are hydroponic/aquaponic systems that use the fish water to fertilize the plants, and once the plants have filtered the water, return it to the fish. Some of the systems are virtually energy neutral, which means that almost as many calories are harvested as are used to grow the food.
The final of the environmental aspects I want to consider today is not directly food related at all. Instead, it focuses on using land freed up by urban farming to begin reforestation. One proponent argues that vertical farming is 10 more efficient than traditional methods, and if cities would grow 10% of the food they need via urban farming, 340,000 square miles of land could be reforested. Others argue that the 10x efficiency is not to be believed, and a better solution would be to quit using feedlots for meat production and reforesting the land formerly used to grow the massive amount of corn and soy needed to power the feedlots. The same individual argued that ‘factory farming’ plants is no more environmentally sound than factory farming meat.
In the end, it seems that urban farming is still in too amorphous a state to easily nail down as a positive thing for the population and environment or not, but it’s a subject to keep watching. To me, it seems to be an issue of adaption. People see a need or opportunity and try to use it to aid in our survival. The reason urban farms are so varied is because I imagine no one method will work in every place. It reminds me of when I talked to Jedd Koehn for my article on Coastal Plains Produce. He started with a new location and a desire to get to spend more time with his family, so he took his farming knowledge and adapted his growing methods to fit his needs, which is how he got into hydroponics. I talked to him for a local perspective on large scale and indoor urban farming. He said that there are lots of variables to consider, and location makes a difference even with indoor farming, because of issues like humidity affecting the systems. He also said it can depend on the crop grown, as the system would work better for, say, tomatoes versus some other plants. (Turns out, it takes around half the energy used by an average American refrigerator in a year to produce 2.25 lbs. fleshy foods like corn, but the turnaround is much better on plants like greens where most of it can be consumed). Whether indoor urban farming will work on a large enough scale to sustain a population is yet to be seen, but Jedd that it works for him and his family, and I’d say that’s a pretty good start. As advancements are made, we’ll see how the fate of large scale urban farming turns out. Until then, keep your eyes open. What looks like a warehouse may actually be a farm.