The iAVs promise reads…..
iAVs has the capacity to produce fish and fresh vegetables sufficient to provide a family with 200 kg of fish and 1,400 kg of vegetables (fruit) per year in a footprint equal to an automobile parking space. *
*Assumes a sub-tropical or temperate climate or controlled environment that will permit year-round plant production.
That’s a bold claim and one that should be quantified…so here’s the detail.
Use of this comparative scale was suggested by Dr. H. Douglas Gross (Professor Emeritus, Crop Science at NCSU – Assistant Director, International Programs). He/we thought that this would be easily ‘appreciated’ by AID bureaucrats. We were wrong in that assumption, but do hope that you will ‘see’ the potential of even small scale Lo-tech iAVs.
Context here is Lo-tech, such as for LDC, ‘Third World’ application. Yield from Moderate- to Hi-tech iAVs (e.g., with powered aeration, protection/shelter, CO2 amendment, Etc.) can be from 2 to 3 times greater per unit area/time than indicated here.
The following is based on an area of 3.5 m x 8 m = 28 m2 , or approximately the size of a typical parking space.
Of this area, 18 to 20 square meters is used for the bio-filter/grow bed. Premised on 4 tomato plants per square meter grown as single-stems at 3 crops per year = 234± plants per year. With 234 plants each producing 6 kg of fruit = 1,404 kg yr-1.
When growing tomatoes – or a similarly vertical and lengthly crop – for the first month or so when they are small, the grower can simultaneously produce a second short duration crop 3 times/yr. Options include a wide variety of greens and herbs as an intercropped ‘understory’ – and/or other species in various combinations.
The fish production is premised on 40 to 50 kg m-3 yr-1 depending on feed quality, temperature, DO levels, harvested size, and other factors. The tank would occupy about 4 to 5 square meters with a volume from 4 to 6 cubic meters.
Yield of 200 ±50 kg LW Tilapia per year at a typical market size (in much of Africa) of 250 to 300 gram LW each. This harvest size may be achieved in from 100 to 120 days from the 15 g fingerling stage.
Harvesting either as batches (cohorts) several times per year or as individuals selected daily/weekly (as desired), or in some combination of household use and cash market sales or barter.
If (when) operated without access to electrical power, the remaining area (2 to 5 m2) would be used for a cascade-aeration ‘ladder’ sited between the filter’s outlet and the tank. With electric power, the remaining area may be used to increase the grow bed area and/or tank volume.
Please notice that I have not claimed that this is the most practical configuration, rather it is what could be fit into the given area.
iAVs will produce more food, faster and do so using FAR less water (and energy) than any other method of food production with a comparable capacity.