Lesson video

Hello, my name's Mrs. Harking.

The title of today's lesson is The Future, Hydroponics and Aquaponics taken from the unit Natural Resources, Can Earth Meet Our Needs? We will explore how farming can happen without any soil.

Let's get started.

Our outcome today is to investigate how hydroponic and aquaponic systems function and explain their potential to revolutionise sustainable farming.

Our keywords that are useful to know before we start the lesson today include hydroponics, aquaponics, and sustainability.

Now, hydroponics and aquaponics, we will go through in more detail in the lesson, obviously.

Sustainability is something I'm expecting you to know.

Let's run through these and check if you're happy with them.

Before we begin, if you would like to pause the video at any point and note anything down, feel free.

Hydroponics first, this is using nutrient-rich water to grow plants without soil.

Aquaponics is using nutrient-rich water from farming of aquatic animals to nourish plants.

Sustainability, meeting the needs of the present without compromising the ability of future generations to meet their own needs.

The outline of our lesson today comes in two parts.

Firstly, what are hydroponics and aquaponics? And secondly, how can these revolutionise farming? So let's start with what are hydroponics and aquaponics? The word hydroponics comes from the Greek roots.

So hydro means water and ponics is to do with labour.

So this reflects its core principles, using nutrient-rich water as the medium to grow plants without soil.

We can see a diagram here of plants growing with their roots in the water rather than in the soil.

So plants are placed in containers or channels where their roots are exposed to a water solution with artificially-added nutrients.

This delivers essential nutrients directly to the roots, allowing for faster growth.

So here on the right-hand side, we can see this image and the white channels actually contain water, and the roots of those lettuce plants will be suspended and held in the water so that the nutrients from the water is going directly to the plants.

There's not any soil there.

Sometimes they use little, almost baskets to hold the plants.

Sometimes they do have pallets.

They haven't got any nutrients in or anything, but they just hold the plants in position in the little container.

But again, the nutrients all comes from the water.

Hydroponics can use water in different ways.

Firstly, roots could float in oxygenated nutrient solutions, which is what we've just seen.

Then there's another option.

A thin nutrient film could flow over the roots in a sloped channel.

And finally, nutrients could drip onto the roots via timed emitters.

So all of these would be a form of hydroponics.

It's commonly used for leafy greens, herbs and tomatoes, especially in greenhouses or vertical farms. So we can see on the right-hand side here that this is a vertical farm, meaning there's almost shelves of plants growing one on top of the other.

The lettuce here is an example of a plant that grows really well.

Not all plants can be grown in this way.

Farmers monitor and control pH balance, the oxygen levels and the nutrient concentration.

So it does require quite a lot of monitoring and tweaking to make sure that the plants are being produced in the most efficient way.

Time for a check for understanding.

Can you select the correct statements? Is it A, a nutrient solution delivers essential nutrients directly to the roots, B, the nutrient solution creates slower growth, C, hydroponics can use water in one very specific way, or D, it is self-sufficient in controlling pH, oxygenation and nutrient concentration? Well done, yes, it's A, a nutrient solution delivers essential nutrients directly to the roots.

So if we look at B, it's not a slower growth, it's faster growth that will happen.

C, hydroponics can use water in more than one way.

There were three different ways we looked at, wasn't there? D, it's not a self-sufficient system.

People need to monitor the nutrient levels in the water and tweak that as well as the pH and oxygenation as well.

Now we're looking at aquaponics.

So this looks like it should be the same thing, doesn't it? Aquaponics, aqua we know has to do with water, but this is quite a modern word and it's taken from aquaculture.

So the aqua comes from aquaculture, which is normally fish farming.

It can be farming for other seafood or aquatic animals as well.

Ponics comes from hydroponics.

It reflects its core principles.

It uses water from aquatic animal farming to nourish plants.

Aquaponics combines aquaculture, raising fish or seafood, with hydroponics in a closed-loop system.

Fish waste provides nutrients which are pumped to the plants.

So fish waste, fish poop, fish (indistinct) will go into the water and that will then provide nutrients to the plants.

The plants benefit from this because they get the nutrients.

Also the fish benefit.

So the plants then help filter and clean the water to be sent back to the fish.

It mimics the natural ecosystems and is considered a really sustainable method of food production.

Not all plants can be grown using this system.

Popular plants include lettuce, basil and spinach.

So again, those leafy greens are the ones that are focused on for these sorts of projects.

Common fish include tilapia, goldfish and catfish.

Maintaining water quality, so the pH, the oxygen, the ammonia levels is essential for balance.

So again, people are required to put quite a lot of careful monitoring and tweaking into this process.

Time for a check for understanding.

Hydroponics uses water from aquatic farming to nourish plants.

Is this true or false? Well done, that is false.

If you said true, have another look.

Right, can you tell me why? Very good.

Yes, so this describes aquaponics, not hydroponics.

Task time now.

I'd like you to firstly complete the definitions of hydroponics and aquaponics using some, not all, some, of the following words.

So we have to choose from open, closed, agriculture, hydroponics, aquaculture, with, without, nutrient, slow, fast, pineapple and aquatic.

So hydroponics uses rich water to grow plants.

Soil.

This allows for growth.

Aquaponics combines with.

It uses water from farming to nourish plants in a loop system.

Secondly, I'd like you to draw a diagram for each to explain how they differ.

Good luck, everyone.

Pause the video now to give yourself time to do this.

Well done.

Let's take a look at some answers now.

Firstly, I asked you to complete the definitions of hydroponics and aquaponics.

So your answers should look like this.

Hydroponics uses nutrient-rich water to grow plants without soil.

This allows for faster growth.

Aquaponics combines aquaculture with hydroponics.

It uses water from aquatic farming to nourish plants in a closed-loop system.

So each of the correct answers there is in a different font to help you identify them.

Check your own work and check that you've got that all correct.

Feel free to edit your answer if you need to at this stage.

Secondly, I asked you to draw a diagram for each to explain how they differ.

Your diagrams may look like this.

Firstly, we have hydroponics where we can see nutrients in the water are added artificially, whereas aquaponics, aquatic animal waste adds nutrients to water, which is pumped to plants.

So the key difference you need to have in your diagrams is that there must be some water with fish in for your aquaponics.

That's the key thing.

Onto the second part of our lesson today.

How can these revolutionise farming? Hydroponics and aquaponics require less inputs and also produce better outputs.

Aisha says, "Surely aquaponics and hydroponics will need more water than traditional farming," and she has a point, right? It's in the name aqua, hydro.

We should have thought that actually a lot of water will be used in this process, but it's not the case.

So actually they require 90% less water than traditional farming.

This is because water is lost in traditional farming to evaporation and runoff.

But these are limited or prevented entirely in hydroponics and aquaponics.

So if you had a field with soil like you would normally see in a farm and you watered that field, not all of that water would be absorbed by the plants.

Some of it would evaporate, some of it would run off.

So every time you water, you're having to use fresh water to add to those plants.

Whereas with these systems, the water stays contained within pipes.

So the same water will cycle round and round, and it will just be that actually the nutrients are tweaked and added and the oxygenation and the pH levels will be altered rather than actually having to add any water to the system.

There will need to be water added.

But as we can see, 90% less than a traditional farm.

The high levels of monitoring and control in hydroponics mean the plants receive exactly what nutrients they need, eliminating the unsustainable overuse of fertilisers common in soil farming.

In aquaponics, aquatic animal waste supplies nutrients.

This eliminates the need for chemical fertilisers.

Without soil, the risk of soil-borne pests and diseases drops dramatically, reducing the need for pesticides.

So actually less fertilisers, less pesticides.

This is really quite positive, isn't it? Quick check for understanding now.

Why do hydroponics and aquaponics need fewer chemical inputs? Is it A, controlled systems and natural nutrients reduce fertilisers and pesticides, B, plants grow faster so no nutrients or pest control are needed, or C, using less soil slightly reduces fertiliser use? Well done, yes.

So controlled systems and natural nutrients reduce fertilisers and pesticides.

As these farming techniques can use vertical farming, less land is needed and they can even be located in cities.

This can reduce the food miles, which is the distance the food has travelled, and is often associated with carbon footprints.

So if the food hasn't had to be transported from say, a hot country far away all the way to us, that means that all of those methods of transportation that are polluting our planet releasing carbon dioxide and other greenhouse gas emissions, all of that won't be happening.

So the less transport, the better.

The closer the food is produced to us, the better.

Controlled environments, often indoors, allow for year-round production as crops can grow regardless of season or climate.

This again means that we're not having to have crops from abroad from maybe a hotter country, because these crops can be grown in our country close to home preferably, and they can be grown inside in controlled conditions.

Obviously, there's going to be some electrical or energy of some sort requirement in order to heat the greenhouses to the right temperature, but fundamentally, the food miles will be reduced.

Aquaponics produces both vegetables and fish or seafood, offering protein and greens from one system.

So a lot of the fish that are used within these systems are actually edible.

These systems are less vulnerable to droughts, floods, and soil degradation, which is key in a warming world.

So many areas are experiencing desertification.

Soil is losing nutrients, more deforestation is happening in order to access soil which is more nutritious.

So removing the requirement for that soil to be there providing the nutrients can actually help us in these changing times.

Aquaponics have been introduced by non-governmental organisations, that is often charities.

In the Zaatari, refugee camp Jordan, to tackle malnutrition and water scarcity for Syrian refugees.

Carp, herbs and leafy greens are farmed in households and small community clusters.

They're built using locally available materials, so recycled containers, PVC piping, this sort of thing.

This has increased access to fresh food by over 70%.

This is an absolutely fantastic case study to show us how using an innovative farming methods in an unusual location can really improve people's lives and their health as well.

I've popped a picture of the refugee camp on the right-hand side and located it on the map, just so you can see where it is.

Time for a check for understanding now.

Have small-scale aquaponics farms been a success in Zaatari? Select the best answer.

Is it A, yes, the plants have grown well and provide fresh food, B, no, the project has led to a reduction in fresh food, or C, yes, it's increased access to fresh food by over 70%.

Yes, well done, the best answer is C.

So although A is correct, I asked you to go for the best answer, remember.

So C also includes a percentage to give some real factual information to back up our claim.

Another check for understanding.

Can you tell me why is Zaatari an appropriate location to practise aquaponics? There's two main reasons.

Firstly, there's a need for this food here, so it's a really good idea to do this in situ where the demand is.

Secondly, it's the best farming method, because it doesn't use as much water, and there's water scarcity in this region.

So the farming methods that use the least water are the most desirable.

Less carbon dioxide is emitted through hydroponics and aquaponics compared to traditional soil-based farming.

This is because tilling soil, which is turning it over to prepare it for planting, you can see this happening on the right-hand side, releases stored carbon into the atmosphere.

Something you may not have known.

The production of artificial fertilisers used in soil farming produces carbon emissions as well.

The yield, the amount of crop produced, for both hydroponics and aquaponics is higher than soil-based farming.

We can see here on the right-hand side a bar chart which shows us the yield.

So if we take the baseline as soil farming as 100% yield, hydroponics would produce about 120 to 130% of that.

So 20 to 30% more than traditional farming.

Aquaponics on the right-hand side actually produces 250 to 300% yield.

So this means that it's 150 to 200% better in terms of its yield than traditional soil farming.

What really helps here is that actually, it's not just the plant crop that's being produced, but also the fish that are being produced that can be eaten as well.

Let's go back to this diagram.

We said that hydroponics and aquaponics require less inputs.

So these inputs we know now are water, so there's less water, less fertilisers and pesticides, and less land and soil.

The outputs are lower carbon dioxide emissions and higher yields, so actually producing more of the good stuff and releasing far less of these emissions that are going to damage our planet.

Time for a check for understanding now.

Soil-based farming releases more carbon emissions than hydroponics and aquaponics, as.

Is it A, tilling soil releases stored carbon into the atmosphere, B, fertilisers and soil remove carbon from the atmosphere, or C, the production of artificial fertilisers releases emissions? Well done, yes.

It's actually A and C.

So if you've got either of those, well done, but if you've got both, brilliant, that's really great.

Hydroponics and aquaponics do require careful monitoring, maintenance and electricity for the pumps.

They can also be costly to set up.

So it is worth noting that this isn't a magic solution that solves everybody's problems. There are still going to be challenges.

Time for a check for understanding.

Hydroponic and aquaponic systems are completely self-sustaining or maintenance-free.

Is this true or false? It is false.

Why is that? Yeah, so they require regular monitoring, energy inputs and human intervention to stay productive.

Lucas asks, "If you were going to set up a farm, which farming style would you choose and why?" Would you go soil-based, hydroponics or aquaponics? Interesting.

Feel free to pause the video now to discuss further.

Task B, can you evaluate which farming method is most sustainable? We have the three options here, soil-based, hydroponics and aquaponics.

I would like you to include the inputs required, for example, water, chemicals, soil, electricity, and setup costs, and the outputs, for example, yield and carbon emissions when you're considering how sustainable each of these is.

I suggest that you use one paragraph for the benefits and then one paragraph for the disadvantages.

Pause the video now to give yourself time to do the task.

Well done, everyone.

Let's take a look at some answers.

Right, so evaluate which farming method is most sustainable.

Your answer may include both hydroponics and aquaponics require fewer inputs, no soil, minimum water, and reduced chemicals, minimising the environmental impact.

Aquaponics produces the highest yield, as fish or seafood are reared alongside plants.

In the Zaatari refugee camp, aquaponics provided an increase of over 70% in fresh food, demonstrating the benefits to society.

Did you get any evidence into your answer? That would be a nice thing to add if you didn't have that in already.

However, these systems have drawbacks, including high setup costs, energy demands, and technical complexity, which can limit accessibility.

However, soil-based farming has more significant setbacks.

For example, carbon emissions from tilling and fertiliser production are far greater than in the alternative farming methods discussed.

In conclusion, aquaponics delivers the best overall sustainability, particularly for society and the environment.

How did yours look? Did you come to a similar conclusion? Feel free to pause the video now to edit your answer.

Well done, everyone.

We've reached the end of the lesson now.

Here's our summary.

Hydroponics uses nutrient-rich water to grow plants without soil.

Aquaponics uses nutrient-rich water from farming of aquatic animals to nourish plants.

Hydroponics and aquaponics require fewer inputs, no soil, minimal water and reduced chemicals, and they produce higher yields than traditional farming.

In the Zaatari refugee camp, aquaponics provided an increase of over 70% in fresh food for farmers.

Hydroponics and aquaponics do have high setup costs, energy demands and technical complexity which can limit accessibility.

Thank you for learning with me today.

See you next time.

Bye.