Skip to comments.Drip Irrigation May Not Save Water, Analysis Finds
Posted on 11/24/2008 1:03:41 AM PST by neverdem
Dan Porges/Peter Arnold
In an effort to make irrigation more efficient to obtain more crop per drop farmers have adopted alternatives to flooding and other conventional methods. Among these is drip irrigation, shown above, in which water flows only to the roots. Drip systems are costly, but they save much water.
Or do they? A hydrologic and economic analysis of the Upper Rio Grande basin in the Southwest, published in The Proceedings of the National Academy of Sciences, suggests that subsidies and other policies that encourage conservation methods like drip irrigation can actually increase water consumption.
The take-home message is that youd better take a pretty careful look at drip irrigation before you spend a bunch of money on subsidizing it, said Frank A. Ward, a resource economist at New Mexico State University and author of the study with Manuel Pulido-Velázquez of the Polytechnic University of Valencia in Spain.
With flood irrigation, much of the water is not used by the plants and seeps back to the source, an aquifer or a river. Drip irrigation draws less water, but almost all of it is taken up by the plants, so very little is returned. Those aquifers are not going to get recharged, Dr. Ward said.
Drip irrigation also generally increases crop yields, which encourages farmers to expand acreage and request the right to take even more water, thus depleting even more of it. The indirect effect is very possibly to undermine policy attempts to reduce water consumption, Dr. Ward said.
Policymakers, he added, must balance the need for more food and for farmers to make a living with water needs.
(Excerpt) Read more at nytimes.com ...
The pdf link to the article is OPEN ACCESS.
The law of unintended consequences, aka human nature, strikes again.
Water rights and water usage will be the next big battle of the west, later the US, and then the world.
Neither does my lameass shower head. Takes twice as long toshower and I can’t find one without stupid water saver device.
I took a drill to my showerhead! Frikken commies!!
Video captures massive meteor as it lights up sky in Canada Link the source.
FReepmail me if you want on or off my health and science ping list.
“Drip irrigation also generally increases crop yields, which encourages farmers to expand acreage and request the right to take even more water, thus depleting even more of it.”
What they heck does that mean???
Basically they produce more food with less water. Which would seem to be the goal, no? But that’s bad because when they succeed they want to do more of it and that’s bad...
The world is upside down.
I’m not quite sure of the line of reasoning here. Apparently it doesn’t “save” water because not as much water is returned to the acquifer. It would seem that if less water is needed, then less water will be taken out of the acquifer in the first place. Relative to the acquifer taking out less should result in less loss.
However, the crux of the concern seems to be that the farmers will ask for MORE water (note that this results in MORE agricultural products) and this seems to be the primary objection.
Am I missing something?
If you are even slightly mechanically inclined, you can simply remove the flow limiter. They are generally made up from a rubber O ring and a piece of circular plastic with small holes that the ring goes inside of. The higher the pressure the more the rubber O ring is pushed to block the flow through the holes in the plastic disc keeping the overall flow more or less the same with different pressures.
If you don’t want to go to the trouble of removing it, just drill a good sized hole through it...
"Drip irrigation draws less water, but almost all of it is taken up by the plants, so very little is returned." Duh.
It takes an “academic” to reason success is failure. The idiot reasoning applied to car gas mileage would be that if cars got 60 MPG they would be cheaper to operate and therefore people would drive more using more fuel... Never mind that the goal of getting higher efficiency was successful, or that people have to spend less for transportation improving their standard of living, it is bad because people drive more... The real goal wasn't higher efficiency or a higher standard of living. The real goal was less driving and in the case, less farming.
No, I believe you’ve hit the nail on the head....
Just proving the goal wasn’t higher efficiency or a better standard of living. The real goal was less farming.
What they heck does that mean???
They're growing more vegetables. Plant cells don't grow in a vacuum, IIRC.
It is more efficient, in other words. It does not seep back into the ground or run off (aquifer recharge areas tend to be uphill from the point in the wellbore where the water is removed). As for recharging the aquifer, only if the aquifer recharge area is directly below the plants, and then one would just be taking the water out and letting it soak back in--likely increasing any contamination from surface sources.
Drip irrigation also generally increases crop yields, (IOW, It works) which encourages farmers to expand acreage and request the right to take even more water, (because it works) thus depleting even more of it.
Thus using more water more efficiently to produce more food. (but depleting the aquifer less to do so per unit of biomass in the first place). Duh.
NO one has yet mentioned the government’s foray into to toilet design. The premise is wrong to start with IMHO. Would someone explain to me how you waste water. Humans consume it for life, but we exhale vapor and excuse the expression, urinate the remains which goes back where it came from. Water can neither be created nor destroyed. No one but God himself knows the limit on the supply, if indeed there is a limit, and I suggest there will be sufficient for as long as earth remains habitable for man.
Government begins with the same letter as God, but any similarity after that, is purely coincidental.
Increasing crop yields with less water is the goal, correct?
Well they admit that it does that - but it is bad because when the farmer succeeds, the farmer wants to do more of the same, well ya... But that is bad...
The genius researcher can't figure out that if the only water used is the water the plant needs the farmer doesn't need to pull as much from the aquifer in the first place to "replenish" it with. The measure ought to be how much food does the farmer produce with how much water and if that improved efficiency makes up for the added cost. Not all this circular reasoning that if the farmer succeeds at producing more economically he'll use more water...
As you say, there is no shortage of water.
Only cheap water.
I guess in NYT land, creating successful technologies that farmers can and want to use to increase their productivity and production is bad thing.
Or more food = bad...?