This Summer -- in fact most of the last year -- I have been water desperate.
While I love the challenge I've been mightily frustrated by the lack of rain and my own inability to retain what moisture falls upon my patch of earth.
I use a mix of Leeky Hose irrigation, hand watering and a system of terracotta sweat pots with plenty of mulch -- indeed as much mulch as I can gather as I try to adapt my version of the German wood mulching system known as hugelkultur
I also use shade but the lack of rain has meant that my shade making plants have not been as vigorous as I'd hope so my trellis isn't covered densely by vines so there aint much shade underneath.
So I move on -- another day / another experiment: Solar Drip Irrigation. A Spanish system -- developed in the Balearic Islands-- known as kondenskompressor.
It's simple -- Voila:
Water evaporates onto the roof of the plastic dome and condenses, then falls to water the soil underneath.
So I've started burying bottles of water under greenhouse lids. I'll monitor the evaporation and the moisture content of the soil to see how effective the system is.
With this system you can also use seawater to water your plants. Indeed a similar method is used to grow hyproponic vegetables with sea water in Port Augusta,South Australia.
While I suspect that this method isn't super efficient, I suspect that if you crowded you plants with solar drips you would indeed be irrigating them sufficiently for vigorous growth.
In some illustrations tomato plants are shown encircled by 4 solar drip domes.
That would work, I'm sure, and irrigate for a long time.