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How water could fix our broken food production system
The basics of Hydroponics 🌱🥬🍅🌿
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The word hydroponics can be broken down into two parts: “hydro”, and “ponics”. The word hydro means anything related to water, and the word ponics means labor. Combining the two, hydroponics is a method of growing plants in water instead of soil.
That’s cool, but why?
38% of the global land surface is used to grow plants. One-third of this space is used to grow crops to feed humans, and the remaining two-thirds is used to either grow crops to feed animals, or consist of grazing pastures for livestock. (1) A whopping 67% of global freshwater is used to irrigate crops. (2) 29% of that is used solely in meat and poultry production.
Close to 1 billion people on this planet live off $1 a day and don’t have enough to eat, while the Western world is throwing out hundreds of billions of pounds of food each year. This doesn’t even touch on the environmental impact of agriculture —we are polluting the air, soil, water, and the planet in an outdated, broken food production system.
The truth is that the way we are currently producing food SUCKS.
We👏 need👏a👏better👏food👏production👏system.
Introducing hydroponics: the process of growing crops sustainably in water. A system that can feed a rising population on a hotter planet, without causing any damage to the Earth.
Hydroponics uses 90% less water and 95% less land than conventional farming, and can be grown in any climate, at all times of the year. (3)
Nutrients are dissolved in the water, so plant roots have direct access to the nutrients they need. Plants grown hydroponically, can grow up to 40–50% faster and produce 30% larger yields than plants grown in soil, since they don’t have to process the nutrients they need out of the soil. (4)
Plants grown hydroponically need five things in order to thrive: water, oxygen, root base, nutrients, and light.
Water 🌊
Water is the most important part of a hydroponics system. The entire system is built off water which hydrates the plants, and provides a home in which the plants can thrive.
Oxygen 💨
Without oxygen, the plants will drown in just the circulated water. Plants grown hydroponically will absorb oxygen in the water (water is made up of 2 hydrogen molecules and one oxygen molecule, so water contains a lot of ‘hidden’ oxygen!), and will also receive water from an air pump which regulates the amount of oxygen in the water to ensure that the plants are getting enough oxygen.
Root bases 🌱
The root base is a medium that protects and secures the roots, making sure the plant doesn’t drown. It can be peat moss, rock wool, clay pellets, rice hulls, and anything else that will give the roots some added support and protection.
Nutrients 🧪
In traditional farming, plants absorb hundreds of nutrients from the soil, fertilizer, and nutrient solutions which are sprayed on crops by the farmers. Water lacks most of the essential plant nutrients, so in hydroponics systems, a nutrient solution must be added to the water so the plants can absorb the nutrients from the roots. The three main nutrients plants need are phosphorous, nitrogen, and potassium which are specially formulated to help plants thrive.
Light ☀️
Light is a must to ensure photosynthesis takes place. Full spectrum LED lights provide a concentrated form of energy which is perfect for plant growth.
A hydroponics system must have all five of these elements in order for the plants to stay healthy and produce large yields.
There are several different hydroponic growing systems. They each differ slightly, and offer benefits depending on the crop, space availability, and scale of growth.
The six main types of hydroponics:
- Deep Water Culture (DWC)
- Drip System
- Nutrient Film Technique (NFT)
- Ebb and Flow
- Wick System
- Aeroponics
Deep Water Culture
DWC is the most simplistic hydroponics system. The plant roots are placed directly in the nutrient water, and the air is provided directly to the roots with an air stone or pump. This setup is usually used by small scale-hobby growers instead of commercial applications, because it takes up a lot of space, and is at high risk of algal blooms and water infections because of the large amount of stagnant water.
Almost all plant grows very well in DWC systems — especially heavier plants like squash, zucchini, or tomato, which typically wouldn’t grow as well in a smaller hydroponics system.
Drip System
Unlike DWC where the nutrients are added in the water — in the drip system, nutrients are pumped into a tube directly to the base of the plant. At the end of the tube is a drip emitter that controls how much nutrients are let out. The great thing about this setup is that it can be adjusted for each individual plant. If there is one plant that needs a lot of nutrients, but the plant beside it already has enough, the drip emitters can be tailored to suit the needs of each individual plant, maximizing the efficiency of the system.
Drip systems can either be circulating or non-circulating. A circulating system drips at a slow, constant rate to ensure that the plants get all the nutrients they need. Any excess nutrient water flows back into the reservoir and is circulated throughout the system again. The non-circulating system drips at a faster rate for brief periods of time, flooded the root bases every few hours with nutrient water, and then leaves the plants to absorb the nutrients.
Drip systems are the most common commercial hydroponics system because of how efficient and customizable drip systems are.
Nutrient Film Technique
In the NFT system, the nutrients are added to the water reservoir. From here, the nutrient water is pumped to a slope channel above the reservoir. The water flows through the channel and over the roots of the plants, before flowing back into the reservoir and circulating through the system again.
NFT usually doesn’t use a root base, and instead, the plant is held together by a net pot. Since only the very tips of the roots are getting wet, a root base medium would prevent the plant from absorbing the water and nutrients.
Since the channel is narrow, only small plants (leafy greens) can be grown in the NFT system. *With this being said* the NFT system is the most scalable out of all hydroponics systems, which is why it is commonly used in commercial applications. The NFT system can be easily scaled to grow very large amounts of plants.
Ebb and Flow
The ebb and flow (or ‘flood and drain’ system) is commonly used among small-scale growers. In this system, the plants are grown in a large channel (like the NFT system) which is called a grow bed. The grow bed is filled with a root base like peat moss or clay pellets which mimics soil.
Then, just as the name flood and drain suggests, the grow bed is flooded with nutrient water (from the reservoir below) until it is just a few inches below the top of the bed. The water pump runs off a timer which shuts off the pump every hour. When the pump is shut off, all the water from the grow bed drains out of the channel and back into the reservoir. This gives the plants time to soak up the nutrients and water before the pump floods the grow bed again, and the cycle continues.
Wick System
The wick system is the simplest hydroponic system. It is the only system that doesn’t use aerators, pumps, or even electricity. The plants are placed directly in a root base material (usually clay pellets) and nylon wicks are positioned around the plant base. The end of the wick is submerged in the water reservoir underneath the plants. As the end of the wick absorbs the nutrient water, the entire wick becomes damp, slowly hydrating the plant base.
Because of how long it takes for the wick to hydrate the plants, wick systems only work for plants that don’t need a lot of water — so really only leafy greens. The system doesn’t support larger, ‘thirstier’, plants. The other downside of this system is that the water and nutrients aren’t absorbed evenly by the plants…it all depends on the position of the wick. Plants grown with the wick system tend to be slightly dehydrated and deficient in important nutrients.
Aeroponics
Aeroponics is much different than all the other hydroponics methods. Instead of submerging the plants in water, the plants are suspended in the air. Nozzles below the plants spray a thin mist of nutrient water onto the plant roots, hydrating and nourishing them. The mist nozzles are connected to a water pump in the reservoir underneath the plants which catches any excess water. The pressure of the pump can be adjusted to change the pressure of the nozzles. (Higher pressure of the pump = quicker spray from nozzles.)
Since the plants are suspended in the air they get all the oxygen they need, so aeroponics doesn’t use an aerator. And aeroponics also uses the least amount of water and electricity out of any type of hydroponics system, which makes it the most eco-friendly system.
Hydroponics is not black and white. It’s not either the drip system or the NFT system.
Most growers create a combination of different systems, using aspects of each to create the most efficient system that suits their needs and goals.
And that’s hydroponics for you!
There is no question about it, hydroponics IS the future. We have no other choice.
We cannot continue using 70% of Earth’s freshwater and 40% of Earth’s land surface to grow food.
We are living through a food revolution, and hydroponic farming is just the beginning. From lab-grown meat to genetically engineered crops, to growing food in the ocean and everything in between — these are the innovations that will transform our broken food production system.
Hydroponics is just the beginning.
🚀🔥🌱🥬🍅🌿🌎
Hi I’m Rachel! A 15 y/o who’s main goal in life is to end poverty and hunger. I am an agritech geek currently working on genetically engineering crops to be more efficient and produce higher yields. I like being outside in nature, spending time with my family, and learning about STEM. You can email me at: runnerrachel.lee@gmail.com, or message me on LinkedIn. Don’t forget to sign up for my monthly newsletter here. Thanks so much for reading!
