Water for Food

Photo courtesy of Matt Furber

Agriculture is responsible for some 80% of total consumptive water use in the United States. (Consumptive use is that amount of water effectively lost to the system via evaporation, plant transpiration, incorporation in products or crops, or consumption by humans and livestock.)  Clearly, when we think about water conservation, increasing water use efficiency in the agricultural sector is critical.  And, there are some success stories out there.  A report by The Pacific Institute, California Farm Water Success Stories (Christian-Smith et. al 2010), profiles a handful of farmers, like almond farmer Tom Rodgers, who reduced water use in some of his fields by up to 20% with careful monitoring and irrigation scheduling.  Precision agriculture – using geographic information systems (GIS), infrared satellite imagery, modeling software, nutrient sensors and the like to evaluate crop density, water deficit, stress and other indicators, and smart tractors to apply inputs in a more targeted fashion – has also made tremendous gains. 

Yet, the picture is infinitely more complex than the amount of water applied to fields.  The American diet is extremely meat heavy, and as a result requires tremendous volumes of water embedded in feed and energy inputs.  For reference, producing a serving of beef requires more than six times the water than growing a pound of green beans.  And while we clearly need to reduce our dependence on meat – particularly factory farmed meat – this does not necessarily imply we all need to be vegetarian.  Some really interesting work on the foodprints of residents of New York state by Chris Peters at Cornell University concludes that while a low-fat vegetarian diet requires 0.44 acres of land per person to produce, and a high-fat diet with lots of meat needs 2.1 acres, the optimal diet is a moderate-fat, plant-based diet with a little meat and dairy (and requiring 0.6 acres).  The reason?  While a vegetarian diet requires less land per person, fruits, vegetables and grains must be grown on high-quality cropland; meat and dairy products from ruminate animals can use lower-quality lands.  Peters says “It appears that while meat increases land-use requirements, diets including modest amounts of meat can feed more people than some higher fat vegetarian diets.”  Interesting, to say the least.

And then, of course, we have our antiquated use-it-or-lose-it Western water appropriation system that provides little incentive for water conservation (by agriculture, municipality, homeowners or industrial users), and has been pitting farmers against city dwellers and straining rural economies.  A recent story in the Denver Post cites that 400,000 acres in Colorado were dried up between 2000 and 2005 (USGS data), and another 500,000 to 700,000 acres of irrigated croplands are likely to be lost by 2050.  When water rights in affluent areas are trading for $50,000 per inch – enough to irrigate an acre of land – who do you think is going to win, the farmer or the wealthy second-home owner looking to build an aesthetic pond?  As some Idaho ranchers have been known to say “If I lose my water, I lose my land”.  While agriculture clearly is responsible for a slew of associated environmental problems, we have an equally dark problem: if we pave over much of our open agricultural land, how are we going to feed ourselves?  The answer needs to be multi-fold – we need to stave off sprawl in favor of agricultural lands, but we also need to be smarter about the way we farm:  We need to produce and eat local, organic, whole foods in a water- and energy-efficient manner.

The University of Nebraska’s new Water for Food Institute is putting on what looks to be a fabulous conference on the topic:  Water for Food: Paths to Solutions, May 1-4, 2011.

7 comments to Water for Food

  • Nancy Glick

    Great post. With less than 15% of ariable land on the globe and a forcast of over 8 billion people by 2050 it is clear that major steps need to be taken.

    We will need to produce more food in the next 50 years than we have in the past 10,000 combined.

    I have heard that some studies can show that updating decades old irrigation systems to modern systems can increase crop yields up to 150%.

    Do you have any knowledge of those comparisons? Why aren’t there mandates to upgrade all systems?

    • Thank you! Use of precision agriculture shows promise for reducing water and energy use in some cases, increasing yields. A white paper by Gary Marks, Precision Irrigation: A Method to Save Water and Energy While Increasing Crop Yield, A Targeted Approach for California Agriculture, estimates that California could reduce agricultural water use by as much as 20%, and concurrently reduce energy consumption and peak demand, increase yields and save money, were it to employ precision irrigation using field sensors, weather data and automatic controls. Globally, such high crop yield increases (150%) are often associated with wholescale improvement in farming techniques, including not just irrigation improvements, but approaches like conservation tillage, integrated pest management, integrated nutrient management, water harvesting, etc. Why are irrigation improvements not mandated? My best guess: money. Despite economic returns for upgrades, significant capital is required.

  • Interesting post, but I think we need to be cautious about the Chris Peters analysis. Its conclusions about meat and dairy are based on the ideal scenario of pasturage on marginal lands that wouldn’t be good for raising crops.

    Here in the U.S., however, well over 90% of beef cattle are fed grain in feedlots; they live their short lives without ever tasting a blade of grass. Most other beef cattle get only a taste. On today’s modern corporate dairy farms, the situation is only marginally better. So all those cattle are using a lot of grain–and water. Unfortunately, that’s a food system we’re now exporting to the rest of the world.

    For those who aren’t vegetarians or hunters, maybe that’s one more benefit of asking for grass-fed beef?

    • Thank you for your comment. I agree with you that our current system of factory farms is entirely unacceptable, and that the ideal would be for all of us to be vegetarian, hunters or eating grass-fed beef. Although, even then, there needs to be a balance — how many of us could really become hunters without overhunting? There are more than enough reasons to give up meat raised in our current system. That being said, growing crops using fertilizers and pesticides also brings a slew of environmental ills. Which brings us back to the same solution: local, organic, whole foods raised in a water- and energy-efficient manner. In our transition to utopia, however, we need to think about the best way to balance the use of land, water, energy to feed our populous. It’s in that spirit that I think Chris Peters’ analysis is interesting — the ideal solution will require a mix of food production, perhaps including meat in some places, and will undoubtably vary with location.

  • [...] is highly inefficient. Further, raising meat products requires a tremendous amount of water. For reference, producing a serving of beef requires more than six times the water required to grow a pound of [...]

  • [...] this is just the tip of the iceberg. Our real water use comes in the way of water embedded in the food, clothing, energy, products and services we consume each day. On average, each of us uses over [...]

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