Oh god. This times a million. Big Agra is just slamming in N-P-K 10/10/10 and using center-pivot irrigation[0] during peak sunshine hours because hey, the water table's only 15 meters down! Then to stay competitive average farmers have to beat their land just as hard.

Here's a guy who runs a mini-vineyard in CA who saved almost half a million gallons of water in one season for his grapes using pretty trivial means[1]. I bet if he incorporated some recent 'best/alternative' practices he could get that significantly lower too.

The good news is universities (particularly Australian unis[2]) have conducted pretty thorough analysis w/r/t efficient watering for healthy plant root systems. You have lay new sub-surface irrigation drip system with textile enclosures[3] which is an initial expenditure, but you end up saving a boatload of money on water in the long run. (Drip irrigation[5] in general is alright, but you have tons of water loss via gravity[4] as shown here.) "Permaculture"[6] is a DIY-sociological movement of farming by 'efficient/sustainable/whatever' means.

The bad news is the last time the US had a radical shift in farming was when farmers beat their land so hard we ended up having the Dust Bowl. Conditions had to get so bad that you'd get 'dust days' like 'snow days' from school/work for people to change their farming habits. It wasn't until FDR appointed Henry Wallace(unsung national hero) as Secretary of Agriculture that things started to change. If I could buy futures in water 50 years from now, I'd put my entire savings in it. The botanists and horticulture scientists have made massive advances since the 1930s. We can sustainably farm on land every season if you don't plant corn every dang season and then pump nitrogen in there to make up for the lack of nutrients.

Grey water[7] can very easily be treated and reintroduced into your local garden. We can even use refuse from septic tanks, treat it on-site and re-introduce into your your lawn/garden to produce 100% safe edibles (subject to your local regulations; also, if you're on any sort of medication such as antibiotics, you don't want to introduce that into your ecosystem). No land? No problem. You still can save water. Get a dual-flush toilet[8] which uses half the amount of water to dispose of urine.

I'm not a 'save the earth' kind of guy. The planet was here long before humans and will still be around regardless of all disasters we can possibly throw at it; that's a certainty. Will your grand-children have congenital defects from rampant pollutants, poor air quality, and tainted water is the real question. (I'll end this on a good note - the good news is reforestation can be done in a generation or two![9])

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[0] http://www.lindsay.com/stuff/contentmgr/files/0/6ab577c195d6...

[1] http://hackaday.com/2015/12/11/vinduino-full-irrigation-with...

[2] http://www.unisa.edu.au/Research/CWMR/Students-and-researche... - These guys are doing some interesting work. Most of the Aussie unis are actually. U of Kansas is doing some great work too.

[3] https://en.wikipedia.org/wiki/Subsurface_textile_irrigation - They mention PE and PP but there are alternative materials available which aren't hydrocarbon based

[4] http://www.intechopen.com/source/html/45153/media/image4.png... Effects vary on type of soil (and subsequent density that determines the rate at which gravity pulls water away from the root system), the micro-culture that exists, how water-hungry your plant is, and a boatload of other factors...

[5] http://www.sswm.info/category/implementation-tools/water-use...

[6] https://deepgreenpermaculture.com/diy-instructions/how-to-bu... Water rights will vary from state to state, especially in the Mountain/Pacific zones. It gets as extreme as "you're not allowed to collect rain-water on the land you own, sorry" which is insane because such legislation doesn't even apply to oil/gas/minerals. If you hold full title to an estate (i.e., you didn't just purchase surface rights, or a split claim) and you find diamonds on it, you are issued full rights to it.

[7] "Greywater Reuse" - Amit Gross, ‎Adi Maimon, ‎Yuval Alfiya, 2015

[8] https://www.amazon.com/K-3987-0-Wellworth-Two-Piece-Round-Fr...

[9] https://www.ted.com/talks/shubhendu_sharma_how_to_grow_a_for... I hate TED talks, but this former Toyota salaryman learned about biodiversity from some 80 year old Japanese guru, applied the Toyota manufacturing techniques to make the system efficient, and is doing some amazing work with basically no funding behind him.