A typical measurement in the agricultural community is gallons of water required to fully grow a plant. Some of these are quite astonishing.

The image above is the water required in traditional farming methods, but in hydroponics, there is a huge potential to decrease this ridiculous amount of water being used. Hydroponics uses 70-90% less water than traditional farming and the ways that it accomplishes this impressive number were very interesting when I learned them! Additionally, there is ton less nutrients that are wasted, which are saved in the same way that water is conserved.

There are multiple methods that hydroponics uses to save water and nutrients, but generally it all falls into one category. Hydroponics uses less water and nutrients because it is a closed system. This means that it can eliminate evaporation, catch excess, and recycle the water and nutrients to be used by another plant.

I will start by explaining how most hydroponic systems eliminate evaporation. One form of evaporation that hydroponic systems don’t stop is evapotranspiration, which is when plants soak up water then evaporate through the leaves. This is natural for plants and helps keep the humidity of the air surrounding the plants ideal for fastest growing (80% humidity is ideal). Hydroponic systems do a good job of temperature control to not require the plant to do excess evapotranspiration. Keeping the temperature from getting too hot also has other benefits. The water tanks should remain relatively cool to maximize plant growth, so this is another way indoor hydroponic systems avoid evaporation. This is about the opposite of greenhouses, which heat up a lot, which causes more evapotranspiration, leading to a higher loss of water. The other main way water escapes the system is through leaks, which happen on traditional farms and hydroponic systems alike, and this is controlled by how diligent the farmers/engineers are.

Apart from stopping evaporation by keeping the farms cool, none of the water ever leaves the system, so it never leaves the circulating pump system. This is great news for hydroponic farmers, because then they just need to monitor the nutrient and water levels of the entire system and add water and nutrients when it is getting low. This is a much more scientific method than traditional farming because then it allows the plants to soak up the water and nutrients they need as they grow instead of having to time when you water the plants.

Now we can get to discussing the important part of all this. The application. Lots of places in the world right now have a lack of water. This need ranges from inconvenient to crippling, and with farming being such a large consumer of water, hydroponics offers a unique solution to many countries and regions. The middle east is specifically investing heavily in hydroponic farming because of the energy intensive process of desalination. Hydroponics offers a better solution where much less water is used, and they can get much fresher foods than having to import crops and produce in from all over the world. For regions like these, I expect hydroponics will have the most success in the upcoming years.

Jumping back into the discussion of hydroponics, today I will be covering how hydroponic large-scale farms require much less square acreage than traditional farms and the added benefit of not having to transport the produce much after growing. These two points may not seem that connected, but with a significantly decreased footprint size, hydroponic farms can be placed in many areas that are impossible for regular farms, which means they can geographically be much closer to consumers – reducing the need for long distance transportation of goods!

I will start off by explaining how hydroponics can allow for vertical farms. Because there is no need for soil and sunlight can be artificially produced near each plant, there is no reason to stop us from stacking a hydroponic farm on top of another one! Each level just needs three basic components: 1) a growing medium, 2) a way to get nutrients to the plant (spraying or dipping the roots into a nutrient solution), and 3) lighting (usually LED grow lights). With these three components, farms can be stacked over and over again, each time getting more yield for the square footage. This yield per square footage matters, because current farms require a lot of our land and that may not be sustainable in the future.

Farms in the US use a fair amount of land to grow enough food to feed our people and our livestock. However, the population is increasing and becoming much more urban, meaning that we have to either allocate more land for farmland or become more creative.

In a study from 2015, researchers concluded that “hydroponics offered ~11 times higher yields per unit area, but required ~82 times more energy compared to conventionally produced lettuce” (ncbi.gov). Energy use is the main downside of hydroponics, but I know that by now, the number is less than 82 times. For one, the electricity used in lighting these farms is about 75% of the total energy costs. Everything else doesn’t require that much energy (including pumps, temperature control, and automation) is much less. Lighting efficiency has increased by a factor of 1.5 since the study was conducted in 2015 (as you can see in the graph below).

Additionally, this 82 times more energy required for hydroponics doesn’t account for the energy required to transport crops from the Midwest into major cities to be sold multiple days after harvest. Hydroponics facilities would be able to be built on the edges or even inside major cities, so crops would be way more fresh and have less transportation costs (including gas to run the truck and energy to keep refrigerated trucks cool).

In brief, the energy use of hydroponics is the main thing holding it back (specifically the energy required for creating so much artificial light), however I know that there will be a place for it in society. At the moment, that looks most promising in cities because they would be able to be built very close and supply many people, or in desert/tundra regions where there is very little native food available to be grown. Next week, I will address how hydroponics has a strong chance of being implemented in desert regions like the middle east because of the minimal water it uses!

Hydroponics are such a fascinating topic because it allows humans to grow plants without soil! It’s so counter-historical, yet it works and may be the way forward. Today, I will be covering why soil isn’t needed for plant growth and the benefits that come along with that (primarily no need for pesticides and a very low risk of disease!)

Here’s some context. For a seed to germinate/start growing, it needs two things – moisture and air (1). Soil can provide both because it is porous enough to let air reach the seeds and it can remain moist for a long period of time, letting the seed have easy access to both of the requirements to germination. However, there are tons of different growing mediums that can meet these same criteria. The common ones are shown in the picture below, however seeds can even germinate on a wet paper towel!

When I learned about other growing mediums, I thought it was super cool, but just wait it gets cooler! 😎

There is a company called AeroFarms that has been developing aeroponic systems, which a subset of hydroponic systems where instead of sticking the plant’s roots in a nutrient solution, it mists the plants roots. This means that they can make the growing medium even simpler. This growing medium from AeroFarm’s is quite amazing. “[They] have developed a patented, reusable cloth medium for seeding, germinating, growing, and harvesting leafy greens. The growing cloth medium is made out of BPA-free, post-consumer recycled plastic, each taking 350 (16.9 oz) water bottles out of the waste stream. The cloth can be fully sanitized after harvest and reseeded to minimize any risk of contamination, acting as a barrier between the mist and the plants” (2). The innovation that has already come out of this field and will continue to come in the upcoming decades will make hydroponics even more feasible and I bet a critical part of worldwide agriculture.

Since hydroponics aren’t grown in soil and since they’re grown indoors (out of reach from most pests), there is no need for any kinds of pesticides. Traditional farms do a good job of cleaning off their produce before marketing it to consumers, however with hydroponic farms there is no need for that step, saving money and water. Ultimately though, the cost of building an entire enclosure/building to keep the pests out significantly outweighs the money saved in this area.

On traditional farms, fertilizer is used excessively to help the crops grow bigger and faster. The major problem with this is that the plants don’t soak up all of the fertilizer and some of it is washed away in runoff or it just seeps into the soil and helps the weeds grow (increasing the need for more pesticides). Hydroponic farms do use some fertilizers, but they are applied directly to the plants where there is no risk of fertilizer runoff. This also results in much less fertilizer wasted.

This new form of growing plants is extremely counter-historical, however I think people will like it more if we just call it “innovative.”