Monthly Archives: October 2015

The Advantages and Challenges of Hydroponics

Table HydroponicsHydroponics is a form of hydroculture that allows for the more efficient growth of plants and vegetables on a large scale. The idea is simple: you do away with the usual ‘medium’ used for growing and instead submerge the roots of plants directly into a liquid solution packed with the perfect balance of nutrients.

This create a large number of advantages as it allows for plants to be grown in a more flexible manner, while at the same time encouraging more rapid growth with less space and lower cost. At the same time though, it is not a perfect solution as it simultaneously introduces a number of new issues and challenges. In this post, we’ll be examining the strengths and weaknesses of hydroponics in greater detail to assess its usefulness.

How Plants Grow and Thrive

Hydroponics work because plants don’t actually need soil to survive. Plants don’t actually get any nutrients from the soil itself but instead, the soil simply acts as a carrier for nutrients that come from other sources – from biological material scattered by plants and animals.

Normally, the nutrients seep down into the soil and are then dissolved by rain and absorbed by the plants’ roots. At the same time, the soil provides an anchor for the plants, allowing them to remain in place against the wind and other things that might disrupt them. Meanwhile, photosynthesis occurs, powered by the sun and chlorophyll, and allows the plant to produce carbon dioxide, glucose and oxygen.

We’re used to seeing plants grow in soil as this is where they are normally found. And for people growing their own plants, it’s convenient to use a medium that is available in such supply. However, this also presents a number of other problems. For starters, it means the plants need to be grown outside or in pots, which limits the number that can be grown in any space. At the same time, the roots need to spread out to form a large network to ensure an ample supply of nutrients. Success also depends on weather conditions and can be hampered by issues such as pesticides.

How does Hydroponics Work?

Hydroponics meanwhile do away with the need for a medium, instead suspending the plant in one way or another while providing the roots with a water solution that is already rich in nutrients. This is achieved in a variety of ways, depending on the type of hydroponics being used.

For instance, deep water culture means suspending the plants in a plastic container (or otherwise) with the roots able to hang free underneath, submerged in a body of water. DWC is one of the most common forms of hydroponics and if you have ever seen rows of plants growing indoors in white containers, this will likely have been DWC. Aeroponics meanwhile is an alternative approach that uses a fine mist containing moisture and nutrients rather than a body of water. Wicking meanwhile uses a material such as cotton wool in order to draw the solution out from a container where it can then be absorbed by roots suspended above. Wicking is a good ‘entry level’ approach to hydroponics.

There are numerous other forms of hydroponics but suffice to say they all have ultimately the same aim – to provide a steady supply of water and nutrients without the need for soil.

Challenges

One challenge of hydroponics is that the plants also need to be able to get oxygen and carbon dioxide in order to function. In other words, they need air just like animals. Normally, oxygen is acquired through ‘air pockets’ that exist in the soil.

All hydroponic techniques then need to ensure that the plants are getting access to air in one form or another. In the case of something like wicking or aeroponics, this is not an issue. However, DWC will require pumps in order to ensure the water stays oxygenated. An alternative approach is to use ebb and flow hydroponics, which floods the roots with water and nutrients for a brief spell and the drains the fluid away to give them a chance to breathe. In nutrient film technique (NFT), the fluid runs over the top of the roots along a gradient, allowing the roots to get some air while still absorbing the fluid.

This creates an additional complication when using hydroponics however and means the plants being grown will be susceptible to a variety of complications. It only takes a slight error in the system for a pump to stop working for example, potentially suffocating the plants. Likewise, because the light indoors is normally artificial and controlled by a computer, this is similarly prone to error with potentially devastating consequences.

cucumber plant cultivated in greenhouse.Advantages of Hydroponics

Hydroponics has numerous advantages over other methods of growing because it is potentially much more efficient and much more flexible. Hydroponics requires a fraction of the space required by farming or gardening which reduces the strain that this can place on the environment. What’s more, this means that plants can be grown away from their normal habitats, which has a variety of potential benefits.

Moreover, hydroponics enable ensure that plants get a continuous supply of nutrients that are much denser than is possible normally. And because the nutrient solution is so readily available, there is no need for the roots to spread out as they normally would. This means that more plants can be grown in even smaller spaces and at the same time means the plants will tend to grow bigger, stronger and faster.

With lighting and temperature controlled artificially and no threat from pests, there are very few things to limit or interfere with the normal and healthy growth of the plants.
Ultimately, hydroponics can be viewed like a force multiplier (tool that amplifies output) or a form of automation in business. As with automation and force multipliers, hydroponics allows greater yield from a lesser investment and is thereby more efficient. But also like force multipliers, it can magnify errors and mistakes just as well as desirable inputs.

Hydroponics And Its Ramifications

Hydroponic vegetablesHydroponics is a method of growing plants in water by using solutions of nutrients and minerals, without any soil. Perlite or gravel can also be used to steady the plants as they are growing. The practice of growing plants in pre treated water only goes way back to 1627 when Sir Francis Bacon experimented with the practice, and a book about it that he wrote was published a year after his death.

In 1929 a man named William Frederick Gericke got everyone’s attention when he grew tomato plants to heights of over 25 feet by using mineral nutrient solutions instead of regular soil. Gericke was affiliated with the University of California at Berkeley and he came up with the name of hydroponics.

In comparing hydroponics with traditional methods of growing plants in soil there are some interesting factors that present themselves. Early researchers set out to prove that there was no difference in growing plants in soil or by the hydroponics method. It was assumed from the outset that crop yields were similar in both circumstances.

However, hydroponics does have advantages that tradition plant growing techniques that traditional methods does not possess. In hydroponics the roots of a plant has a constant exposure to oxygen as well as having access to as much or as little water as it needs.

One of the most common errors when growing plants in the traditional way is over watering. With hydroponics this does not happen even when large quantities of water are made available to the plants and the plant will use only what it needs, while any excess water can be drained away.

When growing plants in soil, a gardener or a grower has to be very knowledgeable as to when watering is appropriate for different kinds of plants. If a plant is watered too much, it will not be able to access oxygen properly, and too little water will make it difficult for the plant to transport the nutrients that it needs.

An earlier successful utilization of hydroponics happened on Wake Island in the 1930s, as Wake has no soil. The rocky island was a fueling port for Pan American Airlines, and it was used as a place to grow vegetables for passengers. Hydroponics was successfully utilized for this purpose as it was very expensive to bring fresh vegetables in by air.

Hydroponic tomatoesWalt Disney World featured the EPCOT Center which opened in 1982 and introduced the Land Pavilion which showcased a variety of hydroponic features. NASA has done a great deal of experimentation in the hydroponics field, as they are shooting for a plausible hydroponic technique to grow on Mars when that expedition occurs later.

Hydroponics techniques are labeled as having two types of methods, termed as a solution culture and a medium culture. The solution culture technique uses no solid medium for its roots, as they are just immersed in the solution of nutrients.

There are three primary means of solution cultures which are the static solution technique, the continuous flow culture, and aeroponics.

With the static solution culture technique, the plants are grown in containers such as plastic buckets, jars, tubs and tanks. The solution is lightly aerated, or even un-aerated, but in those cases the solution is kept at a low enough level so that the plants receive adequate oxygen. The solution is changed on a periodic basis and the growth is monitored accordingly. The container size is also modified as the plants grow.

With a continuous flow system, the solution of nutrients is made to flow on a continual basis past the roots. This form of hydroponics is much easier to automate as adjustments can be made to a large amount of medium that affects large numbers of plants.

Aeroponics uses a method that keeps the roots in an environment that is saturated in a mist or an aerosol of the nutrient solution. The roots are literally suspended in a growth chamber where they are systematically sprayed with a fine mist of the nutrients. This technique has been very successful for tomato and potato production, micro-greens and leaf crops.

In the medium culture, the roots of the plants will rest in some sort of medium, such as perlite, rocks, and similar types of medium. Plants have a constant battle against gravity and when they are grown in other environments other than the soil, the actually mature more rapidly.

Which medium to actually use is one decision that hydroponic growers have to make. Clay pellets have been successfully uses as has growstones, which are made from glass waste as it holds a good bit of air and water.

Coco peat is another medium used, as it is the material that is left over after all of the fibers have been removed from the shell of the coconut.

Perlite is a volcanic rock which has been heated to extremely high temperatures, and is formed into very lightweight glass pebbles. Other medium are used with great success, as new medium are being tested on a regular basis.

The nutrient solutions that are used in hydroponics contain micro organisms and fertilizer. There are various lighting systems that are employed to provide the adequate light that the plants need to grow.

Hydroponics has enabled the growth of plants to occur just about anywhere the system can be set up, both indoors and outdoors. The flexibility and the fact that much more can be grown in smaller spaces is revolutionizing the way we think of growing and harvesting plants on a very large scale.