Vertical Farming

This article written by co-op student Thomas Tinmouth delves into an innovative process that may change farming on earth as we know it. This read will be sure to give you the necessary information about all things vertical farming.

Approximately 5 billion hectares of earth’s land is designated for agriculture. This is about 38% of land on the planet, with one-third being used for cropland, and the remaining two-thirds for meadows and pastures. As the human population continuously grows, so does demand for food, and as food intake increases, so does the strain on our planet to keep up with the need for more produce. By 2050 the population will rise to an estimated 9.8 billion, and in order to keep up with food demand, the United Nations predicts food production must increase by 70%. At some point we will hit a cross road as more humans on the planet means more land area taken up, but also more space needed for agriculture in order to feed everyone. 

Overpopulation is a very real issue that will bring with it negative effects, but blaming all our issues on having too many people is an excuse. There is enough food on the planet to feed everyone, enough water to keep everyone hydrated, and for now, enough land to keep everyone housed. So in the same breath of blaming overpopulation, shouldn’t we also say overconsumption? Though this can be a whole other topic in itself, it raises the question as to how overconsumption and overpopulation will be dealt with in terms of food. There are a few solutions such as changing your diet or trying to buy local and in season from sustainable farms. These practices can help, but there is another simple idea that may be a large piece in finding a solution to this problem. Instead of growing outward and taking up more land, why not grow upward?

What is Vertical Farming and How Does it Work?

Vertical farming is the practice of growing food on layered platforms that stack vertically rather than horizontally, which is the traditional farming process used in fields. These stacks can be integrated into existing structures such as shipping containers, buildings, and warehouses. Through the use of controlled environmental agriculture (CEA), indoor farming is possible as temperature, light, humidity, and gases can all be manipulated to create a prime environment to grow food inside. The controlled environment must be maintained correctly or you risk losing the crops, similarly to if extreme weather ruins outdoor crops. The main goal of vertical farming is to produce a quality product using the least amount of space, while maximizing output of produce. There are multiple ways that vertical farming can be successful, but for the most part there are four areas that must be understood. The first is the structure of the indoor farms. Refer to figures 1-3 to see a few different vertical structures used for these types of indoor growing techniques. Growing vertically increases the amount of food produced per square metre. The second area you must understand is lighting and microclimate. It is truly amazing how the CEA is able to create personalized climates based on the food being grown to ensure year round growth. Mixing artificial light with natural light, coupled with turn beds, and the perfect combination of nutrients and humidity create the optimal microclimate to be able to grow spinach in the winter, and herbs during hurricane season. The third area to understand is the growing medium. This is where hydroponics comes into play as the common practice for vertical farming is to use mediums such as pete-moss, water, and coconut husks rather than soil. The fourth area to understand is the sustainability aspect. For example, by using non soil growing mediums there is 95% less water used. I’ll get more into this area a bit later. 

Figure 4: Largest vertical farms in North America.

What Can Vertical Farming Grow?

It is theoretically possible to grow any plant indoors with vertical farming technologies, but based on economic factors such as maximizing space and ability to quickly grow and sell, there are certain produce that work better than others. The following list are the most commonly grown produce in vertical farming facilities, though are not limited to only these foods.

Summer squashHerbs
PeppersLettuce
EggplantSpinach
CantaloupeTomatoes
English CucumbersStrawberries
Microgreens & sproutsMushrooms

Comparing Vertical Farming to Traditional Farming

Yields

A 2014 study, “Up, Up and Away! The Economics of Vertical Farming,” published in the Journal of Agricultural Studies, compared yields of vertical farms using CEA to traditional field farms. The study concluded that vertical farming produced on average 516 times as many tonnes of food per 10,000 square metres compared to traditional field farms. For example, Pure Greens (vertical farming) grows plants in stacks of five, with each stack containing a 16 square foot row. 90 basil plants are put in one row, compared to traditional soil farms where basil is placed a foot apart. This vertical farming technique makes it possible to grow 16 plants in 16 square feet. This means that the hydroponic vertical system produces 5.6 times more basil per square foot. When you factor in all five stacks that’s 28 times as much basil per square foot. Safe to say average yield is greater for vertical farming than traditional soil methods.

Land Use

Approximately 1 acre of an indoor vertical farming facility produces the equivalent to 4-6 acres of traditional field farming. Way more food can be grown per square foot in indoor environments due to stacking the plants, ending up saving mass amounts of land area. For example, every Eden Green Technology greenhouse built (vertical farm) there is 31 acres of land saved.

Energy

Arguably the biggest drawback of vertical farming is the amount of energy it uses to operate the facility. Approximately 3,500 kWh a year is needed per square meter to grow lettuce. 98% of this energy is used for lighting and climate control. A small vertical farm will spend on average $3.45 per square foot on energy while larger farms spend $8.02. Traditional field farming energy use varies based on what is on the farm, how big the farm is, and how sustainable the operations are. Though vertical farms will produce more output of produce, their electricity input is greater than most traditional field farms.

Emissions

Though sustainable in many aspects, vertical farming is not necessarily a saviour when it comes to greenhouse gas emissions (GHG’s). Due to the high amount of energy needed to manage lighting and climate within the facility, there are emissions as result. The average vertical farm system uses 130 kWh per day, equalling about 117 lbs of CO2. On the other hand traditional farming practices have inputs such as fertilizers, runoff, deforestation, water usage, and other gases emitted such as methane which all contribute to their emissions. These traditional practices account for approximately 11% of worldwide GHG’s.

Cost

It is approximately 3-5 times more costly to grow in a vertical farming environment compared to  conventional field farming. This is largely due to the costs involved with energy consumption in vertical farming. A conventional outdoor farm costs $0.65/lb to grow a pound of produce while a vertical farm costs $3.07/lb.

Advantages and Disadvantages to Vertical Farming

Figure 5: Advantages and disadvantages of vertical farming.

Is Vertical Farming the Future of Agriculture?

Figure 4 displays the advantages and disadvantages of vertical farming. After researching positives and negatives, my conclusion is that vertical farming can be part of the solution, but is not the saving grace of food production, at least not right now. Yes there are less inputs and positives in terms of being climate resilient and undisturbed from weather, but emissions, energy use, and cost are really holding vertical farming from being the sustainable solution that our world needs. This is not to say it won’t help as it can be very positive in moderation, but it’s just not ready to be the world’s main source for growing food. Vertical farming, along with other innovative sustainable food production methods will continue to be developed as they are necessary to keep up with food demand and lower environmental impact of farming.

We as humans cannot solely rely on innovation to solve our problems, as if we rely only on what tomorrow may bring, we risk today, and the lives of future generations who may not get to see the world in the same vibrant colours we did growing up. Creating new methods of growing food is important, but so is preserving what we already have. Far too much food is wasted falling victim to our habits of overconsumption, a scary reality that when paired with overpopulation, will result in deadly and unjust consequences.

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