No Soil? No Problem! An In-Depth Look at Hydroponics

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Hydroponics is a popular (and rapidly growing) horticulture method that involves growing plants without soil.Thanks to years of research, there are several hydroponics setup options today. Success in hydroponics is achieved when root health is carefully monitored.

Plants growing in a greenhouse in a hydroponics setup

Hydroponics is derived from the Greek words “hydro”, meaning (you guessed it) “water”, and “ponos”, meaning “labor. Put simply, Hydroponics is a horticulture method that involves growing plans with only water, nutrients, and (typically) some sort of growing medium. That’s right, no soil! The goal of hydroponics is to remove as many obstacles as possible between plant roots and water, oxygen, and nutrients.

Hydroponics is a proven technology that has been well-researched and developed over time. While there are a few minor drawbacks to utilizing hydroponics (versus growing plants in soil), the potential benefits are dramatic. There are several options for hydroponics setups which allows for significant customization and versatility. Whatever method is utilized, success in hydroponics is most likely to be achieved when root health is carefully attended to.

A Brief History of Hydroponics

Early Research

The earliest recorded information on growing plants without soil can be found in “A Natural History” by Francis Bacon published in 1627. This publication spurred an interest in water culture research. In 1699, John Woodward published his experiments with water culture and spearmint. He discovered that plants cultivated in “dirty” water sources grew better than those grown in distilled water.

By 1842, a list of elements essential for plant growth had been agreed upon by most researchers. The discovery of these essential elements along with the research of German botanists Julius von Sachs and Wilhelm Knop led to refined techniques for soilless cultivation. .

In 1929, a professor at University of California Berkeley, William Frederick Gericke, began publicly pushing for solution culture to be used in commercial agriculture applications. Gerickie’s research gained attention when he successfully used solution culture to grow tomato vines in his backyard that measured 25 feet long. His contemporaries, however, were skeptical that solution culture could be as effective as traditional agriculture. In 1937, Gericke coined the term “hydroponics”.

Growing Success

One of the earliest successes of commercial hydroponics was born out of necessity. In the 1930s, Wake Island, located in the Pacific Ocean, was used as a refueling stop for Pan American Airlines. Because the island lacked the necessary soil and environment to grow produce, hydroponics was used to grow vegetables for the passengers.

In the 1960s,the Nutrient Film Technique, a popular method used today, was developed by Allen Cooper of England. This technique involves a shallow stream of water containing dissolved nutrients being recirculated around the plant roots via a gully or channel.

A hydroponics display at Living With the Land at EPCOT, Walt Disney World

A Hydroponics Exhibit at Living With the Land, Part of Walt Disney World’s EPCOT

In 1982, Hydroponics become part of a popular attraction. Walt Disney World’s EPCOT opened “Living With The Land”.This park feature is a large pavilion that prominently features a variety of hydroponic techniques like those pictured above.

Modern Hydroponics Applications

KENNEDY SPACE CENTER, FLA. – In a plant growth chamber in the KSC Space Life Sciences Lab, plant physiologist Ray Wheeler checks onions being grown using hydroponic techniques. The other plants are Bibb lettuce (left) and radishes (right). Wheeler and other colleagues are researching plant growth under different types of light, different CO2 concentrations and temperatures. The Lab is exploring various aspects of a bioregenerative life support system. Such research and technology development will be crucial to long-term habitation of space by humans.

Over the past few decades, NASA has done considerable hydroponics research and development for its Controlled Ecological Life Support System (CELSS). This research is done in an environment that mimics that of Mars.LED lighting is used to grow plants in a different, cooler color spectrum. Ray Wheeler, a plant physiologist at Kennedy Space Center’s Space Life Science Lab, believes that hydroponics will create advances within space travel as a bioregenerative life support system.[12]

In 2007, Eurofresh Farms, located in Willcox, Arizona, sold over 200 million pounds of tomatoes grown in hydroponics setups. Eurofresh developed 318 acres worth of hydroponics crops and represented approximately one third of commercial hydroponics in the United States. ( In 2013, Eurofresh’s greenhouses were acquired by NatureSweet Ltd.)

Thanks to continual technological advancements and several economic factors, the global hydroponics market is expected to grow from it’s 2016 value of $226.45 million to $724.87 million by 2023.

The Pros and Cons of Hydroponics

Like anything, hydroponics has its pros and cons. However, when done carefully, the cons become minimal and the pros become phenomenal successes.

A Few Drawbacks

While we think hydroponics is pretty amazing, we’ll be the first to tell you there are a few drawbacks to going with this growing method. Most notably, hydroponics setups can be expensive and more difficult to manage that traditional growing methods. Some additional disadvantages include:

  • Mistakes and malfunctions will affect plants more quickly. Soil can act as a buffer, guarding plants against any complications.
  • Any waterborne diseases will spread quickly.
  • Because most hydroponics systems rely on electricity, a power outage could seriously impede a crop’s success.
  • Hydroponics setups require higher quality water.
  • An artificial growing environment demands close supervision.

Looking on the Bright Side

Hydroponics growing methods boast some pretty impressive advantages; however, it’s important to note that these successes only occur when systems are carefully set up and maintained. Unlike outdoor gardening, in hydroponics, beautiful, healthy, fruitful plants don’t happen by chance. When properly tended to, hydroponics setups offer the following benefits:

  • Growers have complete control over the nutrient balance.
  • Hydroponics gardens require 80% less space.
  • No pesticides are required if the setup is in a sterile environment.
  • Less physical labor is required (tilling, fumigation, mulching, etc.)
  • Crops are not limited by season; plants can grow year round.
  • Plants grow at least 20% faster. Because it’s easier for plants to receive nutrients, more energy can go towards plant growth.
  • Hydroponics setups can be installed just about anywhere.
  • Hydroponics systems require about 20 x less water.
  • Plants boast a 25% greater yield.

Supplies for Hydroponics

No matter the technique, a hydroponics setup will require a nutrient solution and a growing medium. Additional supplies often include a growing tray or netted pots, a reservoir, a water pump, and an air pump. However, these supplies are dependent on the method used.

Nutrient solutions always include Nitrogen, Potassium, Phosphorus, Calcium, Magnesium, and Sulfur. Additional nutrients that may be included are: Iron, Manganese, Boron, Zinc, and Copper

Rockwool, the industry standard for growing medium

There are likely hundreds of growing mediums available, however the industry standard is either rockwool (rockstone), perlite, or vermiculite. In recent years, alternatives such as polyurethane grow slabs, rice hulls, sphagnum moss, oasis cubes, coconut fiber, sawdust, gravel, sand, and expanded clay pellets have become increasingly popular.

Techniques

While hydroponics setups vary fairly notably,the most common approaches can be summarized in the following six methods:

Deep Water Culture System (DWC)

Deep Water Culture Systems, or DWC, keep plants suspended directly in a reservoir of nutrient solution. Plants are typically placed into net pots with a growi

ng medium for support. Roots grow out of the netted bottoms of the growing containers. This method is attractive to many growers due to it being relatively inexpensive and easy to set up and maintain. However, this

method is not ideal for large plants or plants with long growing periods.

Wick Systems

Wicking Systems transport nutrients and water from reservoir to root zone via wicks. Wicks can be simple materials like rope or felt. The key to a successful wick system hydroponics setup is to use a growing medium that transports the nutrient solution well. This setup is a great option for

smaller plants that don’t require a lot of water and nutrients. Furthermore, if set up correctly, this

method is mostly “hands off”. It’s important to note that large plants may have trouble getting enough nutrients and water from wick systems.
Ebb and Flow Systems
Ebb and Flow Systems, also known as Flood Drain Systems, are a less common hydroponics setup. In this setup, plants are grown in a tray full of growing medium. The tray is flooded a few times a day. This is done via a water pump that moves the nutrient solution from a reservoir to the growing tray. The frequency of flooding depends on factors such as plant size, air temp, and where the plants are in their grow cycle. Ebb and flow is an extremely flexible setup that allows for custom medium, plant placement, and flood frequency, This system requires significantly more growing medium that other methods, making it more expensive. Additionally, if the pump fails or ambient conditions change quickly and drastically, roots could dry out quickly.

Nutrient Film Technique (NFT)

The Nutrient Film Technique, or NFT, is a popular option, especially for commercial applications. Plants are grown suspended above channels. A nutrient solution constantly runs along the bottom of the channel, coating the roots in a “film” of the solution. The nutrient solution returns to a reservoir after passing through the channels where it is recirculated. NFT requires minimal growing medium. Unfortunately, any pump failure could ruin crops. Also, overgrown roots could potentially clog channels.

Drip Systems

 

Drip systems are not unique to hydroponics and were originally created for use on soil-grown plants. In a hydroponics setup, plats are places in a tray or individual pots with a growing medium. A nutrient solution is pumped from a reservoir and through drip emitters. Typically, each individual plant has at least one drip emitter feeding it the nutrient solution. Drip systems are relatively cheap when done on a large scale and allow for close control of water flow. Furthermore, drip systems are less likely to malfunction than other setups. Drip systems are a great option for large-scale growing; smaller operations, however, may find the setup to be overkill.

Aeroponics Systems

Aeroponics systems are perhaps the most “high-tech” option when it comes to hydroponics setups. They operate by constantly, or nearly constantly, misting the root zone with a nutrient solution. Growers have the option to mist the roots on a frequent cycle (allowing only a few minutes between each cycle) or the constantly mist roots with a finer mist. In aeroponics, roots are often exposed to more oxygen than in submerged hydroponics setups; this is because misting allows for constant aeration of the nutrient solution. Aeroponics setups are typically the most expensive and difficult to set up. Specialized nozzles are required. Moreover, any nozzle failure will lead to quick root drying.

The Key to Success: A Healthy Root Zone

Roots of plants in in hydroponics setup before being submerged
When it comes to any branch of horticulture the root zone is where the magic happens. Because the root of a plant is the start of its vascular system (where nutrients are absorbed), it’s crucial that this area is well cared for.
As we’ve mentioned, hydroponics allows for careful control of the growing process. This provides excellent opportunity to meticulously care for plant’s root zones. A notable factor that significantly affects root health is temperature. More specifically, nutrient solution temperature.

Why Temperature Matters

A nutrient solution and, consequently, root zone, that gets a little too warm could lead to plant heat stress, wilted plants, aborted fruit, slow growth, and dangerous pathogen growth. At the root of these issues is low oxygen. The warmer a nutrient solution gets, the less oxygen it’s able to support and transport to the root zone. What’s more, as temperatures rise, root zones actually need more oxygen! High temperatures put plants in a tough situation: roots need more oxygen but nutrient solutions are actually carrying less oxygen than usual.

A Cool Solution

FluxWrap from North Slope Chillers keeping a nutrient reservoir at proper temperatures
For serious hydroponics horticulturalists, a cooling solution may be required to maximize crop yields. Hydroponics water chillers are a convenient way to keep nutrient solutions at optimal temperatures as they circulate through the reservoir. North Slope Chillers take up minimal space within your current hydroponics setup, are almost effortless to install, and are made to order– that means your cooling solution can be custom tailored to fit the needs of you operation. If you’d like more info on what cooling solutions are available for your hydroponics setup, give us a ring at (866) 826-2993 or shoot us an email at [email protected]