Ever since the Agricultural Revolution of 10,000 BC, humans have been growing food by planting seeds in the ground. This has sustained the population successfully for the last several millennia, but this isn't to say the system is free from obstacles that farmers have always battled with.
Hydroponics is a relatively recent innovation which challenges us to somewhat rethink everything we think we know about what farming has to look like. It proposes the paradigm shift that plants do not actually need soil to thrive - they just need a substrate that can deliver the essential nutrients and water they need to grow. As it turns out, these hydroponic systems carry several benefits, and could be the way humanity feeds itself for centuries to come.
Traditionally, crops are grown in soil. Critical to the plant's growth and ultimately yield, is the state of that soil the plant is growing in. Agricultural technology has progressed enormously in the last century, and we now can analyse a range of factors such as soil pH, moisture, porosity, nutrient content, and more. However, the system is never totally efficient, and nutrient and water losses, as well as weeds, disease, and pests are always going to be an issue.
In hydroponic farming and hydroponic systems, the soil is replaced with nutrient-rich water instead. It is the responsibility of the hydroponic farmer to manage and maintain optimal nutrient levels in the liquid solution, as well as the frequency of supplying the nutrients to plants. Hydroponic systems also conveniently side-step a lot of the issues outlined above faced by traditional farming.
There are few core elements that make up a successful hydroponic farming system.
Plants love water that is highly purified and filtered, and maintained around pH 6-6.5. There are different solutions available over the counter that can be used to maintain the desired pH balance, which will vary depending on the type of crop being grown.
Just like in the soil, the roots of the plant are scavenging for oxygen. In order to avoid drowning the plants, it is vital to ensure there are enough air bubbles in the water to begin with. This can be managed with an air pump or an air stone.
Even though they're not fighting their way through soil in a hydroponic farming system, plant roots still need something to latch on to for some support and structure. The most popular substrates used for this include vermiculite, perlite, peat moss, coconut fiber, and rockwool.
Key minerals all plants love include magnesium, potassium, calcium, phosphorus, and nitrogen. In traditional farming systems, these would be administered via compost, mulch, or mineral fertilizers. However in hydroponic systems, these are added directly to the water to form a well-balanced solution. It is worth bearing in mind that your "plant food" mixture might affect the pH of your water, so take this into consideration when planning your hydroponic farm.
Of course, plants require light to grow and thrive. Different plants have different Daily Light Integrals - the amount and type of light that they require. If growing indoors, there will likely be a need to invest in specialized lighting systems.
Hydroponic farming systems have several advantages over field crops grown in soil. Here are some of the benefits you can expect from a hydroponic farm.
Hydroponics are usually grown indoors, which comes with its own host of advantages, the main one being the ability to control several environmental factors with fine-tuned precision. With these highly-optimised growing conditions set up and maintained, the plants have nothing to do but grow fast, strong, and healthy.
In these systems, plants are fed with nutrient solutions mixed with water, which gives the hydroponic farmer total control over nutrient delivery and frequency of administration. Not only does this make the system more efficient in terms of resource use, but it also helps minimise plant energy being used on seeking nutrients as they are soaked up directly. The result is faster-growing, healthier plants.
Hydroponics eliminates the risk of soil-borne diseases. They also don't face competition from weeds, since they cannot propagate if they were never introduced to the system in the first place.
Plants grow 30-50% faster in hydroponic farms than in soil. Such process of growing plants without soil is due to the reduced environmental stress (they're typically grown indoors), and optimised delivery of water and nutrients to the plant. With sufficient water and nutrients, the plant doesn't have to worry so much about survival, so it can focus its energy on growing fast instead.
When planted in soil, roots need to travel far to find water, so plants need to be planted a certain distance apart from each other. This is not the case in hydroponic farming, meaning these soil-free systems take up much less space than their traditional counterparts.
Because plants can be planted more closely together than in soil-based farming systems, hydroponic farms tend to produce more yield per square foot than almost any other kind of farming. Additionally, growing indoors means all kinds of crops can be grown all year round. The limitations of weather are effectively removed, meaning hydroponic farms are literally lean, mean, production machines.
80% of the water used in the USA is on irrigation of field crops. This number is so high because a lot of the water ends up being lost - it isn't taken up by the root and drains into the groundwater (if the soil is nice and porous). Hydroponic systems use 10x less water because it is delivered in a controlled and highly efficient way.
Hydroponic systems hold a lot of potential to blossom into a significant contributor of food production for local communities. Urban areas could see freight containers or similar popping up, housing vertical hydroponic systems and farms to create hyper-local food supply chains. This will improve local food security, and provide access to high-nutrient foods for those who might not otherwise have it.
Read more: Aquaponics in a Nutshell