Richard writes:

Hi Vincent / Dixon

Not exactly a podcast related email. More to do with vertical farming.

I’ve spent the last few months designing an led based lighting system, targeted at saltwater, and coral aquariums. Needing to have a constant output, compensating for ageing, and specific output spectrum. I wonder if this would be of any use in vertical farming?

I can see that it might be useful, in extending day length, and in the case of some plants producing the correct light spectrum to trigger flowering. This might be useful in growing crops outside the normal zone. Eg simulating equatorial sunlight, that eg vanilla orchids (and other things I’m sure) require.

Being led, and liquid cooled, gives advantages, of high efficiency, and long life. As well as being able to re use, sore and re use, or remove waste heat.

With day extension, this may well be possible using solar power, and the correct sort of battery, with no external energy input.

I just wondered if this would be of any interest? If so I’d be happy to work towards a more sustainable future. The vertical farming concept being of interest to me, as a solution to solving future food issues.



Bill writes:

Dickson, Vincent:-

It seems to me that a research experiment to  create a vertical farm with a portion that created nitrogenous and CO2  waste partnered with a plant portion that used the nitrogen and CO2.

Nitrogen is one of the main costs of plant growth, as well as Potassium and assorted trace elements – and it is one of the major waste products of animal production.

Vertical farms attain near perfect control of aphids and other plant pests with exclusionary methods that create a fully organic crop.

Similarly, shrimp and fish farms are plagued by parasites and viruses and would also be amenable to an exclusionary method of pest control.

So each crop would start off with pest and pathogen free eggs/seeds/shoots and by feeding only sterile food and nutrients could achieve a well integrated system. Crops and animals can start off  at the same stage and as each grew the wastes of each  would feed the other. Some experimentation would determine the sustainable load of each crop, so they matched their mutual use of wastes. In addition, the building could have hundreds of tanks and plan flats, with crops starting weekly in various tanks/flats and being harvested weekly as maturity occurred. I am sure supplemental nutrients would be needed as it would be impossible for a total match, esp for various conserved minerals which would be needed by all things grown.

As long as a sterile perimeter was maintained and sterile eggs/seeds/shoots were used  along with well trained people and sterilized feed/trace elements were provided, such a place could stay contaminant free for a long time, although there needs to be a method of bulkhead isolation as on a ship – just in case a contaminating event occurred so the bulkheads could be sealed to prevent spread.

{{Back in 1960 I worked as a student at a summer job at Connaught Labs, in Toronto, (now Sanofi-Pasteur) and they were responsible for WW2 Penicillin bulk production in very large fermentation vessels. At startup up, they made 42 consecutive 1000 gallon batches that became contaminated with competing organisms before they were able to create contamination free product from which penicillin was extracted. They went through a number of types of contamination, and eliminated them but a very persistent  problem was eventually traced to channelling in the filters used, and these channels allowed traces of  competing organisms to enter intermittently  A batch was watched with care and as soon as a contaminant was detected, dumping and sterilization took place =next, as they were under great pressure to produce due to war injuries and with no problems with resistance, Penicillin saved many lives on the front.}}

Free ocean fish/ farms and land based tanks/ponds are quite low in cost for fish and shrimp, but do have problems of assorted contamination occurring and the methods used to kill sea lice etc, prevent the ‘organic’ label from being attached.

It might be possible for an integrated vertical plant/fish farm I describe to prosper. I think it is worth exploring. In fact, they may have them out there now – I  have not seen them on the web though.

Saundra writes:

Here’s a couple of suggestions for future guests: Stephen Ritz, Green Bronx Machine; Tim Blank, Future Growing.

Bill writes:

Dixon, How do various places levy realty taxes on farms located in industrial

buildings that are not abandoned?

Carol writes:

Dear Drs. Dickson and Vincent.  I am thoroughly enjoying your podcasts!  Although I’m retired, I do quite a few lectures under the Master Gardener umbrella of the Un. of Tennessee. My most requested subject seems to be container gardening of vegetables.  I’m about to embark on growing a small amount of veggies indoors, as soon as construction is complete on my new sunroom. My first instinct is to use my favorite planting medium of 1/3 each, compost (my own), perlite and peat moss. Although your discussions are heavy on lighting concerns, I don’t remember hearing you address soil mixtures.  I’d love your advice on such.

BTW, due to my fairly large store of incandescent light bulbs, I will try using them for heat in this home addition, certainly with a back up system. It is obvious that the windows will emit sufficient heat during most days and at night, a low temperature of 50 will probably be sufficient. May I have your opinion on both factors, night temperatures and soil makeup please? And oh yes, is it okay to keep the lights on the plants 24/7?

Keep up the great work.  You do a really fine job of personal interaction while giving us interesting and useful information in a manner that makes this thought exciting and possible. Blessings to you both, Carol

Andreas writes:

Dear Gentlemen,

I am studying horticulture at Humboldt-University in Berlin (Germany). I focus on hydroponic and aquaponic cultivation methods and follow your podcasts with great interest (my favorite: the interview with Paul Hardej).

Please allow me to address the following questions to you:

  1. with regard to lighting almost everyone is focusing on LED/oLED. However, I read that sulphur plasma lamps are even more advantageous because their radiation spectrum would be closer to PAR compared to LED and that they would be more cost effective. What is your experience on this topic?
  1. growing plants exclusively under artificial light one can achieve growth advantages. What happens if you combine natural with artificial light? Don’t you risk to loose the growth advantages compared to cultivation under entirely artificial light?
  1. what about profitabilty of vegetables being cultivated in vertical farms compared to the ones traditonally cultivated and sold in “normal” supermarkets?

On one hand we should take into consideration low costs, moderate yields and low prices of traditionally cultivated field-grown crops. On the other hand we can achieve better yields, higher efficiency and more competitive prices of organically produced crops but also have to bear much higher costs (higher depreciation for building, technical facilities and operational costs (in particular energy))? Do you have any information on profitability of vertical farms versus traditional farms?

Thank you very much in advance for any help on these matters and please do continue your podcasts.

Best regards,