pros and cons of hydroponics

What Are the Pros and Cons of Hydroponics?

Jane Marsh - August 28, 2020

Hydroponics is a type of aquaculture that uses nutrients and water to grow plants without soil. It is an increasingly popular growing method in urban areas and regions with extreme climates. There are many benefits to hydroponics as an alternative form of agriculture, including fewer chemicals, higher yields and greater water efficiency. However, hydroponics is not a perfect solution. The initial setup is expensive, and the whole growing system is heavily dependent on access to electricity and a clean water source. Here are just a few pros and cons of hydroponics.

Pros

The benefits of hydroponics are myriad and include:

1. More Water Efficient

Growing plants can require a lot of water, and conventional agriculture is historically wasteful of this resource. For example, a single walnut requires almost 5 gallons of water, and an orange uses nearly 14 gallons. Globally, over 70% of fresh water is used for agriculture. Compared to traditional growing methods, hydroponic systems are much more water-efficient. Growing in a climate-controlled environment allows cultivators to use the exact amount of water required for healthy plants, without any waste. Overall, hydroponics utilizes 10 times less water than conventional agriculture.

2. Higher Yields

Since crops are grown in a climate-controlled environment, hydroponic farmers are not limited by extreme weather or annual rainfall, resulting in higher crop yields. There’s more control over the setup of the system, and crops aren’t limited to a specific growing season. Additionally, when comparing vegetables grown in soil, hydroponics can sometimes grow plants at up to 16 times higher density. Hydroponics allows growers to do this without using significantly more nutrients or other inputs. 

3. Less Space

Some crops require a lot of space, and many conventional forms of agriculture are inefficient when it comes to using land. For example, row crops like soybeans and corn take up most of the arable land in the United States, but the harvest is used mostly for livestock and processed food, not human consumption. In contrast, hydroponic systems focus on cultivating fruits and vegetables, providing nutrient-dense food for consumers without taking up significant amounts of space. Additionally, researchers at NASA are studying how to incorporate hydroponic systems for longer-duration space missions by providing the right balance of light, carbon dioxide and water. 

4. Community Resilience

Many cities have significant food deserts, and access to quality and affordable items is significantly limited. Urban hydroponic systems enable communities to cultivate their own crops, increasing food security for vulnerable populations. While hydroponics requires significant operational costs, there is also some proof that it may be a possible solution for countries that struggle with food insecurity or need back-up options during months of extreme drought. For example, in the United States, many agricultural enterprises grow food in one region but ship it to another for consumption. Many rural communities struggle with access to healthy produce because of this. Hydroponics may help foster community resilience by setting up an accessible system.

5. Fewer Chemicals

Many advocates of hydroponic systems stress that hydroponics reduces the need for synthetic chemicals. Since plants are most often grown in greenhouses with strictly controlled environmental inputs, pest pressure is almost nonexistent. Considering the detrimental impact of pesticides on the environment, using fewer chemicals is a huge advantage for hydroponics compared to traditional growing systems. 

However, there is ongoing debate regarding how to qualify hydroponic crops, and whether they are eligible for organic certification. According to the USDA, this refers to the care and maintenance of soil without chemicals. Since hydroponics do not use earth, many traditional organic growers feel that they are not eligible. Regardless of how crops are labeled, the fact that hydroponics uses fewer chemicals is a definitive advantage compared to conventional agriculture.

Cons

Despite the many positives, hydroponics also has some challenges to overcome.

1. Technology Reliance

Hydroponics is a high-tech process. Most commercial operations utilize specialized equipment that regulates water temperature, as well as acidity and nutrient density. Because plants are cultivated in a completely climate-controlled environment, there is a significant reliance on technology. Hydroponics is considerably more high-tech than other growing methods, and there is an opportunity in agtech to improve yields and decrease inputs. However, the amount of tech also makes it cost-prohibitive for beginning growers.

2. Initial Investment

The hydroponics market is expected to grow from $9 billion to $16 billion in the next five years, so there is certainly an opportunity for investors to consider vertical farming as a viable operation. In traditional agriculture, is it hard for new and beginning farmers to get started, as many face difficulties with land access and infrastructure investments. However, getting into hydroponics is not necessarily any easier or cheaper. Despite a growing market, the initial investment in hydroponic systems is steep, especially on a commercial scale. For this reason, many of the largest growers are established agriculture corporations that already have capital in place. The initial investment limits profitable hydroponic operations to a few large farms, making it tricky for smaller growers to enter the market.

3. Organic Debate

As mentioned above, there is an ongoing debate in the farming community about whether hydroponic produce can be labeled organic according to USDA standards. Without a clear definition of the nutrient profile of hydroponics, nor stringent guidelines on which fertilizers or chemicals are permissible, many consumers remain cautious about hydroponic produce. This affects the industry’s success, as many consumers don’t know how crops are grown or what’s added to the water.

Without a clear definition from the USDA, there remains some question over self-labeling of hydroponic crops as organic when synthetic chemicals may still be added.

4. Equipment Requirements

While a home gardener can easily utilize some plastic bottles and storage containers to build a small hydroponic system, commercial farmers have significant equipment requirements. In addition to the initial costs of setup for infrastructure, there are also necessary and costly machines to consider. Pumps, tanks and other controls can be expensive, not to mention electricity and access to filtered water.

5. Waterborne Diseases

While hydroponic systems may reduce or eliminate pest pressure, certain waterborne diseases are more prevalent in hydroponically grown produce. The most common ones affect the plant’s root structure, such as Pythium, which includes several water mold species. Proper hygiene and cleaning practices can reduce the risk of plant disease, but it is often impossible to avoid completely. Because of this likelihood, many hydroponic growers incorporate bio fungicides to prevent breakouts.

Soil-Free Growing

Hydroponic growing can increase crop yields while reducing water usage. The benefits of hydroponics are significant, and the industry is expected to grow astronomically in the next five years. However, there are also some disadvantages to growing hydroponically. Improving access to infrastructure and making technology more accessible will enable more beginning growers to enter the market.

About the author

Jane Marsh

Jane Marsh is the Editor-in-Chief of Environment.co. She covers topics related to climate policy, sustainability, renewable energy and more.