Is Hydroponic Farming Actually Sustainable?

Is Hydroponic Farming Actually Sustainable?

According to the UN, the world is on the brink of its worst food crisis in 50 years.

The global food industry is searching for a more sustainable and accessible system for producing healthy food, particularly fresh fruit and vegetables. Techniques such as hydroponics and vertical farming may provide the solution by maximizing overall output and minimizing the use of space, soil, and other resources.

But what exactly is hydroponic farming? And is it actually sustainable?

Is Hydroponic Farming Actually Sustainable?
Gotham Greens grows fresh produce such as leafy greens in urban greenhouses. | Image/Gotham Greens

What is Hydroponic Farming?

There are a variety of different approaches to Hydroponic Farming. But they all involve growing plants and fresh produce minus the soil.

There are several main styles of hydroponic system. One uses an absorbent wick to transfer nutrients from a water reservoir up to the roots of the crop. While others leave an air-gap, allowing part of the root system to absorb nutrients directly while the remainder is exposed to oxygen in the air.

Plants may also be positioned on a floating raft, or grown through a medium, into which water is regularly pumped. Top feeding also requires regular water circulation, while aeroponics involves leaving the roots completely exposed but frequently filling or misting the space with nutrient-enriched water.

Whatever the precise method used, hydroponics involves regular exposure to both air and nutrient-rich water. According to Vertical Roots, a South Carolina-based Indoor Hydroponic Container Farm, there are five core elements to hydroponic farming. These are fresh water, oxygen, root support, nutrients, and light.

By growing crops in water, vertically, and in climate-controlled greenhouses, Vertical Roots and other similar farms are able to produce nutrient-dense food anywhere in the world, at any time of year, and using fewer resources than traditional methods.

Is Hydroponic Farming Actually Sustainable?
Hydroponic farming is more resource-efficient than traditional methods. | Image/Shawn Ang via Unsplash

Is Hydroponic Farming Sustainable?

Soil-less farming techniques, in general, are typically more resource-efficient long term than traditional methods. According to the National Parks Service (NPS), hydroponics can use up to 10 percent less water than field crop watering.

By operating a closed-loop system and recycling rainwater, high-tech greenhouse developer AppHarvest uses up to 90 percent less water than traditional methods.

Most hydroponic farms utilize closed-loop systems, like AppHarvest, that contain and preserve water. This control over the water system also allows for delicate adjustments to the environment. PH levels, amount and type of light, and quantity of nutrients can all be modified to enhance the growth of crops.

Emphasizing perennial agriculture—particularly in combination with vertical farming and hydroponics—can further maximize both production and nutritional content per-plant. Many perennials, which can be maintained all year round with no replanting, are extremely nutrient-dense.

Start-up costs for hydroponic systems are typically greater than for traditional farming. But overall, it produces far greater output with fewer resources. It also allows growers to produce food anywhere in the world. Thereby reducing the carbon emissions generated through transportation, and allowing for year-round production in even inhospitable environments or weather conditions.

In general, hydroponic systems can produce a greater yield of fruits and vegetables. This is in part due to the controlled environment, but also because plants can be housed much more densely than possible using traditional methods. This both increases the overall output and reduces the quantity of land required.

Is Hydroponic Farming Actually Sustainable?
Vertical farming can decrease the amount of land used for fresh produce even further. | Image/Markus Spiske via Unsplash

What is Vertical Farming?

Vertical farming involves the growing of vegetables in stacked layers, frequently in a controlled environment.

Vertical farming also requires much less land than traditional methods. Typically, it incorporates controlled-environment systems such as hydroponics to maximize output. The primary goal of vertical farming is to increase the crop yield while reducing the space required, much like hydroponics itself.

Vertical farming firm Infarm recently partnered with supermarket chain Marks & Spencer to grow fresh herbs in select stores. The company is also working with several retailers and chefs across Europe who aim to add small vertical farms to their restaurants and stores.

“Our vertical farms can be installed directly in any urban space,” said Emmanuel Evita, global communications director at Infarm. “Which is where the majority of the global population will live in the next few decades.”

It is particularly useful for growing produce in areas where there is a lack of arable land. In Abu Dhabi, where there are extremely high temperatures and increasing water scarcity, the government is investing $100 million in indoor farming.

Inner-city gardening, in general, also lends itself to vertical farming. While harder to create a controlled environment, guerilla gardening and other community-based projects have also made use of the vertical system. This enables greater access to fresh produce and reduced mileage overall, even with rudimentary systems in place.

Emphasizing perennial vegetables could also maximize nutrients, increase production, and reduce the consumption of resources.

Why Do We Need Alternative Farming Methods?

Studies indicate that the suburbanization of major supermarkets has led to food deserts within cities. This disproportionately impacts low-income people and those who live in urban areas. Traditional malnutrition affects around two billion people worldwide. But the Standard American Diet (SAD) and lack of access to fresh food is also responsible for chronic deficiencies.

Access to fresh fruit and vegetables is likely to become even more restrictive in the recession following the COVID-19 coronavirus pandemic. And even in countries with plenty of food, there will likely be further disruptions in the food supply chain.

In order to provide enough vegetables for the global population to maintain a healthy diet, food production would need to triple. Alternative methods such as vertical farming and hydroponics could provide a resource-efficient and accessible way of revolutionizing the global food industry.

Gotham Greens, a fresh food farming company, specifically choose to build sustainable greenhouses within cities. Local cultivation helps the company deliver products quickly and with minimal energy expenditure. This also allows those who live within urban areas access to fresh, nutrient-dense food, and to agricultural jobs.

AppHarvest is also creating jobs, minimizing its carbon footprint, and increasing its output with its choice of location. By opening a new facility in Morehead, Kentucky, the company is both tackling high local unemployment rates while placing itself less than one day’s drive from 70 percent of the U.S. population. This reduction in travel for delivery has dropped its overall diesel costs by 80 percent.

“It’s time for agriculture in America to change,” said Johnathan Webb, the founder and CEO of AppHarvest. “The pandemic has demonstrated the need to establish more resilient food systems, and our work is on the forefront of that effort.”