Please help criticize this hypothesis.

[Tresmantra]

I was hoping ya'll could help me evaluate a hypothesis that someone I know has formulated. I'm asking because I'm not exactly qualified to point out what's wrong with it (I'm in pre-med, not ecology!).

Here's the jist of it:

Below we will describe a theoretical system which should be one of the most efficient food production systems ever. We have built a prototype and tested it. See Pictures below. We have designed a much larger system for studies and optimization and are ready to build it with your help. The larger scale project will answer many questions of its scalability. Scalability is critical for applying this to the real world.

Gardening requires extreme amounts of water. An average garden which produces 100lbs of vegetables uses ~9000 gals of water. Hydroponics cuts the amount of water necessary by 80% from gardening, but it has problems such as plant diseases that spread quickly and non-organic nutrients that produce bland “robocrops”. AeroPonics solves the disease issues by spraying water and nutrients on the exposed roots (no dirt or substance around roots) in cycles and the roots are healthier when they get a chance to dry out. Aeroponics uses even less water usage than hydroponics but constant spraying is not so easy as atomizers clog with nutrients and are costly and difficult to replace.

Roots need oxygen, nutrients and water. Studies have shown the healthiest roots need to dry out which kills the bacteria and pathogens, but they need to be refreshed constantly. The plant growth in this system is extremely fast and produces abundant and incredible amounts of produce.

We get rid of the need for buying and mixing the nutrients by using “fish”water which is mother nature’s best fertilizer. The water from the fish tank runs through an area which has UV light to kill harmful bacteria in the water before it goes to the plants. The roots are refreshed by water and nutrients by a “flush” action every so often and the roots get a chance to dry. This gets rid of the need for spray apparatus and maintenance. The roots soak up the nutrients and act as a filter to clean and aerate the water returning to the fish. Fish thrive. Plants thrive.

 

[Inferno]

Sources? What hypothesis? This looks like a sales pitch.

 

[Tresmantra]

Sources? What hypothesis? This looks like a sales pitch.

It's a family member's 'hypothesis'.

I agree with you, it feels like a sales pitch—they're not wanting it for scientific reasons but for a general funding program. However, that doesn't excuse the fact that science is involved in this process.

My initial thoughts included the following:
- Organic food? I'm already bored with the idea and the bullshit it comes with.
- UV light to kill 'harmful' bacteria? How would this work, exactly? Why doesn't it kill helpful bacteria as well?
- Different plants need many things beside just supposed nitrogen-enriched air from fish. You have to factor in the microbes that these plants have evolved with; messing with the microbiota might not work too well.

Any other thoughts?

 

[Aught3]

Studies have shown the healthiest roots need to dry out which kills the bacteria and pathogens, but they need to be refreshed constantly.

Get a hold of these results and see if the tests were conducted rigourously and the conclusions actually match the stated claims. The idea that roots are healthier if they constantly dry out is the weirdest thing about this system and, IMO, the one likeliest to be wrong.

Also look in to hydroponics and see if there are any limitations that would apply to this system. That will give you a better idea of where to launch objections.

Organic food? I'm already bored with the idea and the bullshit it comes with.

Agreed. Non-organic 'nutrients' are the same as organic 'nutrients'. There could be an argument that exposing the plant to a variety of soil materials might help it pick up or make more flavour components but it seems like their argument of bland-tasting food could be applied to both hydroponics and this aero-spray idea - if it's even a correct claim.

UV light to kill 'harmful' bacteria? How would this work, exactly? Why doesn't it kill helpful bacteria as well?

UV light filters are the best technology around for sanitising water. The UV light breaks apart DNA and makes the bacteria unable to replicate. It is, of course, non-selective so if the claim is that a UV filter will allow beneficial bacteria to pass through then that is incorrect.

 

[herebedragons]

Hi Tresmantra,

Here are my thoughts / criticisms of this hypothesis:

1. I would expect a source for their claim regarding how much water is used in producing vegetables. The biggest waste of water in gardening involves the delivery system and primarily evaporation. A plant will use a certain amount of water regardless of the medium it is grown in. Controlling evaporation is the key to conserving water.

Studies have shown the healthiest roots need to dry out

2. Sources? Yes some plants do like to dry out between watering (cactus, orchids) but others need to remain constantly wet (cattails, Iris) and die when they dry out. Typical garden vegetables are in between these two extremes, but still don't really like to dry out completely, they need to remain moist but not wet. I am skeptical of the claim that roots need to dry out, at least in the context they are claiming.

3. Organic fertilizer does have some advantage over traditional fertilizers. They are typically more bio-available, meaning they can be more readily absorbed by plant roots because of the form they are in. They also are less concentrated so they are less likely to run off and contaminate non target sources and you are less likely to over fertilize. In addition to nitrogen, phosphorus and potassium, plants need numerous micro-nutrients which would need to be added to any soil-less system. However, the claim of "robocrops" when using traditional fertilizers is non-sense.

4. Their idea of killing all microorganisms to prevent disease is unnecessary. Most plants (something like 95% of all plant species) develop a symbiotic relationship with mycorrhiza, which can often be essential to proper plant development. Growing vegetables in sterile media would not be beneficial.

5. I am trying to imagine the size of the tank and number of fish that would be required to grow 100 lbs of vegetables and it may very well take as much water as the system supposedly saves. They need to do the calculations.

6. If they are sanitizing the water, what will break down the urea produced by the fish into the ammonium form that plants use. Typically bacteria in the soil break down urea. Maybe there are bacteria that would do the job in the fish tank, but usually fish water is poured onto soil, However, it is a very weak fertilizer ... "mother nature’s best fertilizer" ?? not really.

7. Plants take up nutrients rather slowly. They need to have the nutrients available long enough to be able to absorb them. I don't understand what they mean by a "flush action" how much time do the roots spend in water? How would this flush system be different than a hydroponic system?

This sounds like a lot of hoop-la to me, rather than a legit way to grow vegetables.

The best way to grow vegetables is to choose appropriate varieties for the area you live in, use water conserving practices (drip irrigation, mulch, etc.), and apply fertilizer appropriately.

In other words, you should invest in this system because there is a million stupid people that will totally fall for this :lol:

HBD