Technology is cropping up in our lettuce fields

In Yuma, Arizona, agriculture has embraced technology to increase yield.

 


Robert Glennon is a regents’ professor at the University of Arizona and author of Unquenchable: America’s Water Crisis and What To Do About It. Glennon is a contributor to Writers on the Range, the opinion service of High Country News.


Simon Stanley is finishing a J.D. at the University of Arizona, where he is a Sol Resnick fellow. Stanley is a contributor to Writers on the Range, the opinion service of HCN.


In his 1986 classic, Cadillac Desert, Marc Reisner portrayed agriculture in the Yuma, Arizona, region as a poster child for what’s wrong with how water is used in the West. He sketched a situation that would have amused the cartoonist Rube Goldberg: The Bureau of Reclamation built a hugely expensive desalination plant in the desert, and the water it produced cost $300 an acre-foot so that irrigators could continue to grow federally subsidized surplus crops that cost them $3.50 an acre-foot.

Reisner suggested a far cheaper solution: Buy out the farmers and retire the land from agriculture. But Reisner also laid down a challenge, asking whether more efficient irrigation could ever make sense in such an arid region. We’ve investigated that question ourselves by making several trips to Yuma over the past year and a half, and what we learned might surprise you: We think that Yuma’s farmers have been unfairly portrayed and are getting a bum rap.

The lettuce you eat between December and April was probably grown in Yuma, which has become the country’s leading winter lettuce producer. Perennials, such as alfalfa, require peak levels of irrigation when evapotranspiration rates are highest in late summer. Over the last 40 years, Yuma farmers have cut the acreage committed to perennials almost in half. 

Simultaneously, they’ve increased the acreage devoted to vegetables almost six times and doubled water-use efficiency for lettuce. Seed producers, irrigation-efficiency companies, growers, pickers, processors and transporters offer a fully integrated system that culminates in the now-familiar vacuum-sealed bags or boxes of lettuce.

Lettuce growing south of Yuma, Arizona.

We’ve gotten to know about 20 farmers, mostly second, third — even fourth-generation. Their perfected water rights are some of the oldest and best rights to Colorado River water. Yet we found that these farmers continually refine techniques to optimize water consumption. With the help of the latest technology, they identify efficient farming techniques and discard obsolete methods.

Perhaps most impressive is how precisely they level their fields, plant their crops and deliver water to them. Using a combination of state-of-the-art GPS technology and lasers, farmers level fields to within an inch over the length of a football field. Crops are spaced apart with an accuracy of up to one-tenth of an inch. Yuma farmers have also replaced wasteful flood irrigation with misting systems to sprout seeds, and an innovative furrow system to minimize seepage and runoff. A system they are currently developing uses cameras to locate seedlings to minimize pesticide application. 

Although the focus is on product quality and quantity, safety is the third leg of the stool. Yuma farmers have developed new methods to process lettuce and cutting-edge procedures to ensure food safety. For instance, one farmer’s procedural guidelines on food safety filled 10 large three-ring binders. 

Workers daily inspect fields for animal tracks; crops within 10 feet of such tracks are not harvested. They erect fences around fields near animal habitat. Every time any worker enters a field, that information gets logged. Following these procedures generates dozens of daily reports, all available for audit by the farmer’s primary customers — national restaurant chains and produce suppliers. 

We learned that these farmers are clearly proud of their history and accomplishments. They produce twice as much today as they did in the 1970s, using the same amount of water, and altogether they employ 30,000 to 40,000 workers. 

It is true that they still have to pump salt-laden groundwater to get rid of it before it reaches the Colorado River, but a canal diverts that water to Mexico, where it has created and sustains the Ciénega de Santa Clara — 40,000 acres of wetlands that provides excellent habitat for birds and endangered species.

Yuma farmers still use a lot of water because, well, it takes a lot of water to grow any food crop. Meanwhile, the white elephant that is the Yuma Desalting Plant still sits glistening under the desert sun. After its completion in 1992, the plant operated for eight months, until floods and engineering flaws forced its closure. Since then, it’s been mothballed, except for a couple of test runs in 2007 and 2010-2011. 

On balance, we think Yuma’s farmers have risen to Reisner’s challenge. They raise high-end crops as efficiently as they can, and as the Earth’s population increases from 7 billion to 9 billion by mid-century, the changes made by Yuma agriculture offer guidance to other farmers — no matter where they work.

Note: the opinions expressed in this column are those of the writer and do not necessarily reflect those of High Country News, its board or staff. If you'd like to share an opinion piece of your own, please write Betsy Marston at betsym@hcn.org.