Hello Afriendof B,

Sustainable microfarming obviously must include sustainable hydration of crops and the farmer!

Practical solutions are what you want, not philosophy. So, consider that the atmosphere holds 13X10^15 kg times 10^3 km^3 of all of the fresh water on the planet (which is more than all of the glacial ice that as ever been on the planet - except for the ice ages). Another way to look at it is: that is ten times (10X) the total amout of water in all of the rivers and streams on the planet. You have a ready source of water all around you. All you need to do is harvest some.

Atmospheric condensing is a real solution that can be accomplished in an inexpensive way. It depends upon how much space you have. If you are able to have about 1/4 acre of free area that is open space you can harvest enough water each night to feed your garden - plus (depending upon the relative humidity and dew point saturation) for your family needs. Every roof surface can be used but often times is not clean enough to use for direct drinking - you will need to filter it.

So, here is the way to do this ( This requires no electricity to generate the water - you may need it to pump the water or to filter it - but not to collect it):

You will need 4 feet by 8 feet sheets of thin but solid surfaces (4X8 1/4 inch ply works - you can salvage acquire this - or old slider doors the glass will need to be sanded to take the paint - see next step) You will need a framework and catchment system on which to mount this. (Think of this as water farming as opposed to solar energy farming - similar principles).

You will need to paint the surfaces of the 4X8 sheet of material with titanium white paint (obviously a no-lead paint) If you paint the bottom surface of the 4X8, you will need a catchment surface under it. Angle the system so that you have one corner that is lower than the rest. How ever elaborate you make this is up to you, but you can connect all of these surfaces and have a tank to hold the water. A 4x8 surface can produce overnight about one - four liters of water (or more - remember relative humidity and dew point). The slanting of the surface will assure a consistent runoff of condensation.

Water is drawn to titanium white paint - don't ask me why - must be a water social thing - and if your surface is plastic (a good recycling idea might be to make these sheets from melted plastic bottles and flattened on the surface of the 4X8 pylywood. They still need to be painted with titanium white paint. (Smooth is necessary and exposure on a relatively flat angle is, also.

You want to store the water in a closed container - so you will need to circulate it to keep it fresh and pathogen-free, you may also want to filter it - there are polutants in every square centimetre of air now, unfortuantely.

Calculate how much water you need daily to water your crops using drip irrigation, not furrows; build accordingly and you'll be right, Mate.

I have built a solar-powered Atmospheric Vapour Collection System that is about the size of two microwaves that supplies 250 litres a day for me here in Australia. It works 24/7 and adjusts to the dew point temperature so it is at constant dew point.

Hope this either helps or opens up your own thinking process. Any questions - just drop me a note here.
Cheers.

MuziInOz