Vertical Farming: How Plant Factories Stack Up Against Field Agriculture
March 31, 2020
By Jeff Jurgens, AEM Director of Product Stewardship
With the world's population expected to reach nine billion by 2050, estimations project that food production must increase by 70 percent to keep up with worldwide demand. This means farmers will be required to grow more foodstuff in the next 35 to 40 years than the last 10,000 years combined. There is presently not enough farmable terrain to meet this constraint, and due to the negative environmental impacts of global deforestation (including desertification and flooding), clearing more forest for cultivation is not a sustainable option. Vertical farming, with its potential benefits, may play a major role in addressing the growing food demand while minimizing environmental impact.
VERTICAL FARMING DEFINED
Controlled Environment Agriculture (CEA), commonly known as vertical farming, is a growing system designed to weather- and climate-proof the production of food crops. CEA grows crops indoors in stacked, or standing, layers using growing systems such as hydroponics, aeroponics or aquaponics, all of which use a method of nutritious liquid delivery with minimal soil. CEA uses enclosed growing practices, controlling the environment’s temperature, illumination, gases and humidity with the goal of maximizing crop output in limited space.
CEA has become an attractive alternative to traditional farming in areas where arable land is inaccessible or scarce, including metropolitan areas where citizens wish to bring food production nearer to home. Rather than growing crops on a single level, such as in the ground or a greenhouse, CEA produces crops in vertically stacked layers, which can frequently be incorporated into other constructions like high-rise buildings, intermodal (shipping/Conex) containers or repurposed industrial space.
ENVIRONMENTAL CONCERNS
NASA reports that the majority of the world's freshwater supplies are draining faster than they are being replenished with freshwater demand set to increase by 55 percent by 2050. Currently, agriculture is responsible for 92 percent of the global freshwater usage, creating a challenge for even developed countries such as the United States, China and Australia.
A 2017 report found that more than 75 percent of Earth’s land areas have suffered from erosion and water degradation. The continual plowing of fields, combined with heavy use of fertilizers, has degraded soils across the world with erosion occurring at a rate 100 times greater than soil formation. This results in 33 percent of the world’s adequate or high-quality food-producing land being lost at a rate that far outstrips the pace of natural processes to replace diminished soil.
Collectively, this means arable land is decreasing, and poor soil health is contributing to less healthy agriculture, while water demands continue to rise.
COMMON GROUND
Approximately 1.3 billion tons of food destined for human consumption gets lost or wasted each year globally, discarded anywhere along the supply chain, from farmland to supermarkets, restaurants and home consumers. But crops for human consumption only accounts for 55 percent of all crops grown. Nine percent are used for biofuel and 36 percent used as livestock feed. Feed crops, such as hay and soy, are land and water-intensive to grow and the animals that consume them require high levels of water to thrive. Additionally, many types of livestock occupy the grazing land, which constitutes 70 percent of all agricultural land, which is not arable.
BENEFITS OF VERTICAL FARMING
Some of the obvious benefits of vertical farming for is year-round crop production for both human and livestock consumption, consistent quality, and predictable output. CEA holds other environmental benefits, requiring less fertilizer being applied to plants, reducing water usage up to 95 percent and, through weather-proofing, eliminating the need for chemical pesticides. CEA technology allows for faster growth cycles and quicker harvests, meaning more food can be grown every year, in a much smaller space than on a conventional farm. One of the highest-yielding farms grows over 350 times more food per square yard than a conventional farm.
In urban settings vertical farms utilize a farm-to-table order-based system, drastically cutting down on food waste, packaging and the fuel consumption used to transport food—known as food miles—as well. However, the carbon savings are relatively minor even with these novel approaches as at least 80 percent of the emissions for agriculture happens on the farm—not in the processing, not in the transportation. Urban gardening and vertical systems have many benefits, but it doesn’t presently have the scale that’s needed to meet human food demand or reduce environmental impact on a massive scale.
CHALLENGES OF VERTICAL FARMING
Economics is a major obstacle for the broad implementation of CEA practices. Plant factories are currently not the solution to feeding the world's increasing population as competition with crops grown in traditional systems will not be economically viable in the coming years. Plants – not just growers – will need to adapt to CEA growing conditions. Meaning, new crop genetics will need to be designed specifically for vertical farm production that addresses five traits of interest: easy and uniform fruiting; rapid biomass and multi-harvest capable crops; photoinduced quality; auto-harvest friendly traits; and dwarf plants with yield efficiency. It remains to be seen if created, the genetically modified plants would be attractive to an end consumer given the movement of non-GMO products.
CEA approaches require huge capital to launch, as they're high-risk businesses given the cost of production can be quite high per pound of product. Vertical farms are more feasible because of LEDs, but they are still energy-intensive. Proponents of vertical farms often say that they can offset the enormous sums of electricity they use, by powering them with renewable energy —, especially solar panels — to make the whole thing carbon neutral. But just stop and think about this for a second. These indoor “farms” would use solar panels to harvest naturally occurring sunlight, and convert it into electricity so that they can power…artificial sunlight? In other words, they’re trying to use the sun to replace the sun. With current technology, it makes no sense to grow food staples, such as wheat, indoors. A Cornell professor calculated that if you grew wheat indoors, just the electricity cost per loaf of bread made from that wheat would be $11.
Even if a vertical farm boom were to ensue, the output would only be a small percentage of the vegetables and fruits grown on traditional farms and none of the wheat, corn, soy, or rice, at least not in the foreseeable future. Nor will vertical farms raise livestock or grow oil palms, which are mainly what people are clearing hardwood forests to make room for.
THE FUTURE OF FIELD AGRICULTURE
The contribution of vertical farms to overall food production and environmental concerns is to be determined. The greatest potential impact is the implementation of technology in agriculture, partly due to new possibilities with data analysis. Vertical farms have a multitude of sensors measuring many parameters (from, temperature, to nutrient levels). The plants are analyzed with cameras and sensors, which monitor plant health in real-time. As a result, vertical farms are hiring data engineers and sensor specialists as a significant percentage of their workforce. Artificial Intelligence already plays a key role in many vertical farm operations. As sensors continue to get cheaper and more capable, the opportunities for field farms increases considerably.
Farmers will solve agricultural problems — like developing new methods for drip irrigation, better grazing systems that lock up soil carbon, and ways of recycling on-farm nutrients. Organic farming and high-precision agriculture are doing promising things, like the use of artificial intelligence for detecting disease, sensor-activated irrigation systems, and GPS-controlled self-driving tractors.
From the plummeting cost of robotics to the new frontiers of bioinformatics, the future landscape of farming may well look very different, indeed. While this isn't going to happen immediately, growth in the sector will accelerate as technological improvements drive down investment and operational costs.
THE BOTTOM LINE
While civilization wouldn't be where it is today without agriculture, it's a big factor in a number of society's greatest challenges. If farming practices continue unabated, the likely outcome is having to cut down more remaining forests for acreage, destroying even more land and freshwater habitats in the process. Current projections make a global water crisis almost certain.
In light of these challenges, AEM members are looking at every way to reduce the negative impact of current agricultural methods and existing equipment technology. Manufacturers are becoming technology balanced and interdisciplinary, utilizing designers, engineers, horticulturalists, and sustainability managers. AEM members can provide service from concept development to feasibility studies to education and workshops.
IoT devices are guiding precision farming to increase yields. Advanced machine communication is allowing the implementation to control the tractor for optimum efficiency. And manufacturers are developing many alternative power sources, such as advanced battery technology, cable-powered machines, and tractors powered by methane gas. Some concept machines are small enough to fit between rows, using lasers to destroy pests one by one. That is precision farming. If constraints are the catalyst for innovation, then AEM and its member companies are already rising to meet the challenge.
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