Open Source Ecology Forums

Fabiofranca

I think that food production is an important subject that needs more activity in the OSE community.

We have some general references to discuss this subject here:

http://opensourceecology.org/wiki/Category:Food_and_Agriculture

and here:

http://opensourceecology.org/wiki/Open_Source_Agroecology

But I think we need some "think structure" to help the discussion. So I'm proposing a systemic aproach to discuss agriculture and food production in OSE.

We can study any agricultural system as a combination of the following elements:

Physical space >> the area used by the system, that includes the area for effective plant grown, area for crop processing, area for composting, the area needed for the storage of equipment, tools and materials.

Seeds >> Or other form of propagation material (clones, seedlings) of good quality and appropriate for the local (temperature, photoperiod etc)

Light >> necessary to promote photosynthesis

Growing media >> soil or other growing media (compost, hydroponics media etc)Nutrients >> macro and micro nutrients

Water

Basic Materials >> as irrigation pipes and connections, plastic

Equipment and tools >> hoes, tractors, plows, pumps....

Energy >> to move water, to power tools etc

Chemicals (organic or not) >> to control pests, weeds and diseases

Agricultural procedures >> set of operational procedures

Human labor

These elements can be considered as inputs, “withinputs” or outputs of the agricultural system.

Each agriculture technique devised presents a unique combination of these elements to extract production. In commercial agricultural systems, where production in measured in profits not in primary food production, the arrangement of elements give priority to maximizing the use of cheap resources (fossil fuel for energy). Permaculture systems, on the other hand, the emphasis is in maximizing total system production (food, fiber, wood etc), with the maximum use off “free” and local inputs (rain, sunlight, nutrients…).

When discussing an agricultural system, we need, for instance, to address its scale. It is “backyard system” to supply some of the needs of a family, or a large scale farm system, to supply food for a whole city? Each scale will need special considerations on the combination and intensity of use of the elements. In particular, it is important to decide about the equipments an tools to be “open sourced”. A combine and a spader could be adequate to a big farm, but they have no use in a “micro farm” or in a backyard aquaponics system.

I propose that we consider these elements when discussing agricultural issues here in OSE. It is not complete and need some clarification, but I think it is best to post it now as is, and refine it with the help of the OSE on line community.

So what do you think? How to improve this systemic aproach? Which agricultural system should be the priority for the OSE community to open source?

ARGHaynes

The formatting was tough to work through, but as concerns the question at the end. I've looked into a variety of agricultural endeavors as a personal food source and mechanism for augmenting my income. Aquaponics has been the one that I have found most interesting and I have seen several ways to improve it into a more comprehensive system. With relatively small space and moderate levels of input (preceded by a lot of planning) a community could easily be self sufficient in a rather small space.

Fabiofranca

Sorry about the formatting! I already edited the post. Somewhat the text editor I'm using for orthographic correction is playing with the text in other ways. The text is ok on the editor and in the write comment box in the forum, but is weird after posting.

I’m also interested in aquaponics. I think it is a good start for a discussion about food production systems. Which scale of aquaponics do you think should be the priority to start discussing an open source design? I suggest to start with a system with 1,000 square feet of growing media. Big enought for a serious production, but still within the possibilities of an individual to deal with it.

Lets discuss:
What is the theoretical yearly food production of such a system?
Which hidroponics technique is the most convenient for this scale (thin film, flush and drain etc)?
Which materials choose for the tanks and growing beds?
What is the best material for the growing media? How much it will cost?
Which pumps and sensors we should need?
Which plants we can grow in this system? Is it viable to grow beans, lentils, rice, wheat and other grains in this aquaponic system?
How much energy this system are going to consume?
How many hours a day are necessary for the management and maintenance of this system?

laconic_world

What is the theoretical yearly food production of such a system?

I think the following is a helpful start to answering the production projection question. It really depends on what we'd grow, but someone with more farming experience than me can estimate the number of plants in such area of grow beds. It looks like anything but root vegetables has a chance at growing in an aquaponic system.

But how much space do I need? Source: http://www.aquaponicshowto.com/how-much-space/page/60/ "Well that depends on how big a system you want to build and what you make the system out of. We are always being asked how big a system do I need to feed a family of four - the answer is how much does a family of four eat! Consider, how many fish do you want and how many plants do you want to grow. A 1,000 litre (264 US Gallons) tank in your aquaponics system will support between 50 and 80 fish. That will support between 1,200 (317 US Gallons) and 1,800 litres (475 US Gallons) of grow beds taken that the grow beds are about 300 millimeter (12 inches) deep.

A system made up of 1x 1,000 litre tank and two 600 litre grow beds will need at least 18 metres square (200 square feet). That is 3 m x 6 m (10 ft x 20 ft). It would support say 50 fish and a growing area of 4 square meters (44 square feet).

A system with a 2,000 litre tank (528 US Gallons) will hold about 120 to 240 fish. It will accommodate between 2,400 litres (634 US Gallons) and 3,600 litres (950 US Gallons) of grow beds.

A system made up of 1x 2,000 litre tank and four 600 litre grow beds will need at least 32 square metres (338 square feet). That is 4 m x 8 m (13 ft x 26 ft). It will support say 120 fish and 8 square metres (88 square feet) of growing area."

ARGHaynes

I have recently looked into a variety of systems and it seems to me like simple ones are best (duh). To that effect I would say the only technology involved should be a single pump, something to keep the water at the right temperature, aeration devices and a pair of eyes.

I have heard that a system with just fish and plants can be lacking in certain minerals that plants need, so I think it is useful to enhance the water with compost-effluent.

Also useful is:

Aquaponic media bed sizing - imperial.xls

Aquaponic media bed sizing model explanation - imperial.pdf

(The first linked file requires excel or OpenOffice)

It seems to me that one could easily integrate biogas into the production, using sludge to enhance water-nutrient quality, maybe preprocess with Black Soldier Flies to break down scum producing materials, then feed the larva to the fish. Biogas could then be used to maintain the temperature.

laconic_world

@ARGHaynes I think it is useful to enhance the water with compost-effluent

Have you heard that it is iron that gets lacking? Could you expand more on what you're thinking for compost-effluent? Are you thinking cow manure?

Thanks for the helpful documents!

ARGHaynes

Most systems I have looked into have mentioned issues with iron or calcium. I think it makes sense to have a mess of seashells somewhere in the system. They will naturally breakdown to balance out the impact of the nitrogen-bacteria on PH and release calcium in the process. In terms of iron, I wonder if you could just toss in a few nails?

I was thinking any sort of manure or plant waste. Something like the classic "compost tea." Except it goes into the system instead of into your garden.

Also, I think it should be safe to feed the fish duckweed that occurs downstream of a human waste management system, which should capture additional resources.

I am thinking of using the end product of something like this biogas system.

Planned correctly, the only input you would need to the system beyond the actual system, could be others' animal & food waste. Even the pumps could be powered by on site energy. If you had a large sump area and a large initial tank along with a powerful modified diesel driven water pump, you could store the gas produced throughout the day, then run the pump all at once to move the water, then let it drain through the day and begin again.

It makes sense in my head, hopefully I expressed it well.

Fabiofranca

What do you think about creating an especifc discussion about aquaponics?

This discussion here is about a methodology to understand agricultural systems, not to discuss one in particular. If it is ok to you we can ask the moderador to move the post to the new discussion.

I'n really interested in developing An open source ap system. I have some equipment and materials at hand to do some experimenting and testing here.

What i have:
Tillapia fish
Earthworms
Pumps (12vcc and 220vac)
Solar pv pannel
Inverter
timer(220vac)
Fishtank

I don't have black soldier flyes, growing beds and growing media

ARGHaynes

I think it would be a great idea to start another post, let's keep the previous discussion here and as discussions develop, they can create break-offs. I think having a history of discussions might help create a standard for systems.

Howdy, Stranger!

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