If you scroll the net, you will find several websites relating the plus and minus of aquaponics vs soil. However, none of them are exposing real experimentation on this topic. What I offer in this article is to go over the main differences of those 2 techniques. But also to go through an experiment… We will appreciate the growth difference between those 2 production techniques. We will plant different types of plants in aquaponics and in soil and follow the growth over 5 weeks. The result is clear!

 What is the real difference between soil and aquaponics?
Aquaponics
Aquaponics-vs-soil-aquaponics

Aquaponics vs soil plant growth (aquaponics picture)

In aquaponics we are growing plants on a media. The nutrients are coming through the water flow and are always available to the plants. However, a large biodiversity composed of bacteria, fungus, insects, worms… are present on and in the media. They act in the same way as in a soil but at a higher density. Thus, the nutrients available are constantly renewed. As a result, the plants don’t need to develop deep roots. The aquaponics roots are generally significantly smaller than in a classic garden. Aquaponics plants can therefore focus on the foliage and fruits growth.

Soil

Aquaponics-vs-soil-classic-garden

Aquaponics vs soil plant growth (Soil picture)

Growing plants in a soil is common. The plants are growing long roots to absorb the nutrients available into the soil. Plants are also dependent on the rain (or watering) to absorb the water needed to their life. A rich soil will contain a high quantity of organic matters and biodiversity. The life present into the soil is breaking down the organic matter into nutrients for the plants. The worms mix the deep soil (rich in minerals) with the top soil. Therefore, they make essential minerals available to the plants.

how the experiment begun…

empty-aquaponics-grow-bed

empty aquaponics grow-bed after the move

I moved an aquaponics system and had to replant the entire growbed. Hence, I took this opportunity to plant the same crop in the aquaponics system and in the soil. I want to compare the plants growth.

 

The limits of this aquaponics vs soil experiment

Soil garden partially exposed to sunlight

 
As per all experiments, the conditions are never perfect. Ideally, we would like to be able to compare the growth between the 2 systems (aquaponics vs soil). However, here, the soil and the aquaponics system don’t have the same sun exposition. Sun light is one of the most essential plant needs. This point probably makes a massive difference in the plant growth. It partially explains the results obtained. Please take this as a disclaimer, this experiment is not scientific. I just want to share the results obtained.
Why didn’t I chose a more exposed garden?
for 2 reasons:
Firstly: it was the only garden available at this time.
Secondly: If I had used a garden in full sun, I would have had to water the plants very often. Given the hot days we had, I am not sure they would have survived given my low capacity to water it. Indeed, I had to leave for few days and the plants would have probably die.
 

The variety of plants involved

 
I started this experiment with 3 species that are: Basil, Lettuce, and Sage. 10 days later, I added more plants. Among them we have: Basil, Dill, Spinach, Zucchini, Persli, Leek, Chive and Coriander.
Why did I choose those plants? Simply because they are growing in this season and I like them.
 

Let’s start the experiment aquaponics vs soil growth.

 
I buy all plants as seedlings from the local garden shop. They come in little container and I split the container in 2. Half will go into the garden, the other half will go into the aquaponics growbed.

Seedlings for experiment aquaponics vs soil growth comparison

2 weeks later

 
After 2 weeks, we can already see some growth variation. The Basil, Lettuce and Bok Choy have grown very well in the aquaponics system. In the classic garden, the Bok Choy and Lettuce haven’t grown much. The Sage seems to have grown reasonably well in both systems.
 

4 weeks later

Soil-lettuce-small-growth

Lettuce in classic soil garden after 4weeks

Lettuce-aquaponics-high-growth

Lettuce in aquaponics after 4weeks

 

In the aquaponics system, the lettuce are growing extremely well. Basil and all other plants are growing much better than in the soil.
In the classic garden, the lettuce is very shy and there is not much to eat. all the plants are smaller in the classic garden. The zucchini are not too bad but compared to the aquaponics system, it’s way smaller.
It is difficult to quantify the factor responsible for this growth difference. We can’t say what part of the growth is due to the system (aquaponics vs soil) and what is due to the sun exposition. However, the outcome is clear. In this case, the aquaponics plants are growing much faster than in the classic garden.
 

Sidegrowers…

During this experiment, some plants grew out of lost seeds (from last year old fruits lost in the growbed). Many tomatoes grew in the aquaponics grow-bed. Also, what look like a pumpkin plant grew in the classic garden.
Those plants are not part of the experiment. Furthermore, the growth of the tomato is competing with the other plants. I am keeping the tomatoes as I would like to grow them but it’s not really helping for this experiment. I generally let the tomato plants growing as a vine. I direct them aside of the growbed so that they grow but don’t add shade to the other plants in the growbed.
 

Conclusion of this experiment

From this experiment, we can see that aquaponics is producing very well. It is also a very good solution for gardeners who can’t water their garden often enough. It doesn’t involve much maintenance and is accessible to most backyards.

You will probably be interested to discover my six steps to build and manage an Aquaponics system. Click here to access for free!

Thanks and good reading 🙂