18 November 2015
What is Hydroponics?
Hydroponics is a term that crops up now and again in gardening circles, but what is it? Here is a brief guide.
The word Hydroponics comes from the Greek, and literally means 'working water'. It is basically a way of growing plants without using soil, with the plant nutrients being dissolved in water.
The first book on growing terrestrial plants without soil was published in 1627, and by 1842 a list of 9 elements thought to be essential to plant growth had been compiled. Research has been ongoing since then.
Hydroponics can be split into 2 main categories, “Passive” and “Active“.
The passive method of growing is generally the easiest and cheapest. In a passive arrangement the plant is grown in a soil free medium such as Coco Coir, clay pebbles or Rockwool. The main roots reach down to the nutrients solution and draw from this supply for the rest of the plant. There are no active parts and the plant does the work. The growing medium acts as a buffer between the roots and the nutrient solution, ensuring the perfect balance.
An Active setup requires more attention from the user as these systems need to be monitored to keep the balance of pH and EC correct. pH is the measurement of acidity or alkalinity, with the ideal level being between 5.7 and 6.3. The second measurement, EC, is the measurement of dissolved nutrient in the solution. Different levels of nutrients are required depending on the age and type of plant being grown.
Plants absorb the required minerals as ions in water, with soil simply acting as storage. Nutrients dissolve in water enabling their speedy uptake. When the medium is replaced with nutrient enriched water, the plant will nearly always go on to thrive.
One of the most common errors when growing is over- and under- watering. Hydroponics prevents this from occurring, as large amounts of water can be made available to the plant and any water not used, drained away, recirculated, or actively aerated, eliminating anoxic conditions, which drown root systems in soil.
There has been huge investment in research and development of hydroponics systems and techniques, and this is now being utilised around the world for the cultivation of food and medicinal crops.
Some of the benefits of hydroponic cultivation are:-
• Full control of environmental factors and nutrient levels
• Each system can be tailored to a specific plant type to maximise yield and in some cases, shorten the timescale by 50%
• Reduced space requirements for generally healthier, larger plants - 25% more plants in identical spaces
• Water is cycled through the system ensuring minimal or no wastage
• Plant disease is harder to contract and easier to eradicate due to complete containment
Hydroponic gardening has been adopted by many commercial crop cultivators and is currently the fastest growing sector in agriculture.
In Spain, hydroponics has been utilised for over 20 years to grow all year round in an arid, inhospitable environment with exceptional results. Similar schemes have been set up in Dubai, Israel and most recently Australia with the same high level of results.
Hydroponics technology is increasingly being paired with free solar energy lessening its impact even further.
Where land is at a premium, vertical hydroponic systems have started to offer a better option, due to the smaller footprint required.
There are numerous hydroponics systems available with different benefits for every situation or requirement.