Can cacti help San Joaquin Valley farmers survive a drought?

 

When I finally got a hold of John Diener, the busy 62-year-old farmer was en route to his organic broccoli field in central California's San Joaquin Valley. I could picture the scene: a truck bouncing over a dusty track, golden morning sunlight, rows of bright green plants meeting a blue sky.

The vision was idyllic. But this area, one of the nation’s most agriculturally productive, has a problem: in places, the soil is killing the crops it’s meant to grow. Before a maze of irrigation ditches transformed it into an agricultural belt, the San Joaquin Valley was an ancient seabed, a vast stretch of arid soil high in salt, selenium and boron. Now, decades of irrigation and poor drainage have concentrated the naturally-occurring minerals to toxic levels, and the current drought is only exacerbating the problem without rain to drive them deeper into the water table, the soil is growing even less hospitable.

Even the irrigation water is briny; 57 railroad cars worth of salt are pumped into the valley each day, and environmental concerns prohibit farmers from funneling the wastewater back into rivers and ditches as they once did – meaning the minerals accumulating on their land have nowhere else to go. Roughly 400,000 acres are at risk of becoming unusable because they’re too salty.

Some of his neighbors have taken land out of production, but Diener – who recycles 99 percent of his water and has won national conservation awards – would like to live out his days on the farm his family has worked since the 1920s. “I don’t think of land as a disposable resource,” he says. “I don’t want to sell the farm. So the reality is, what are we going to do to remediate the soil?”

Enter U.S. Department of Agriculture scientist Gary Bañuelos, who’s built a career of figuring out what grows best in some of the world’s worst soils. (Chernobyl cabbage, anyone?) Bañuelos says the worst part of the drought for San Joaquin farmers isn’t that there’s not enough water for irrigation, but that there’s not enough water to leach the minerals out. “If you don’t push the salt out of the roots (with water), the molecules migrate toward the surface and bring the salt with them,” he explains. “That’ll eventually kill the plant.”

At least, it kills most plants. But what if there were a plant that thrived in sodium- and selenium-rich soil? One that required very little water and even improved soil conditions by volatilizing selenium – sucking it up and off-gassing it? After decades of research, Bañuelos has patented four new varieties of just such a plant: Botanists call it opuntia ficus-indica. Hispanic-food lovers know it as nopales. See also: prickly pear cactus.

Opuntia, or prickly pear cactus, is a popular agricultural crop in Mexico and the Mediterranean. New varieties may be ideally suited to the San Joaquin Valley. Courtesy Flickr user Cobalt123.

Prickly pear is grown commercially in Mexico, where it’s often pickled and exported to be sold in ethnic foods stores. It’s hugely popular in Italy and the Mediterranean too, and the United Nations recently produced a 163-page report on the benefits of industrial-scale cultivation of the plant in places like South Africa, Morocco and Argentina.

In the U.S., though, outside of a few niche growers, most fresh cactus fruit comes from the D’Arrigo Brothers in Salinas, Calif. They sell the red pears to Italian chefs on the East Coast, as well as for blending into trendy cocktails and adding to salsas. One food blogger describes the flavor of nopales as “green beans spritzed with kiwi.”

Diener doesn’t plan to compete with the D’Arrigo Brothers in the fresh fruit market. But a few years ago, he planted about 20 acres of spineless cactus on his Red Rock Ranch because he thinks there’s a secondary market on the verge of going mainstream: prickly pear as a health food and nutritional supplement. Whole Foods and Jamba Juice already promote it; WebMD says it’s good for hangovers; and Bañuelos confirms health nuts’ claims that it’s high in vitamin C and antioxidants. Plus, the extra selenium and dearth of water in San Joaquin soil may produce cacti with more beneficial nutrients than those grown for purely culinary purposes.

Prickly pear is usually started from cuttings rather than seeds; both the fruits and pads are harvestable within a couple of years. If the market is as successful as Diener and Denver local-food activist Adam Brock predict it will be (Brock calls it “the future of food” in Colorado), the California farmer plans to expand his operation and even begin diverting some of his carefully-rationed water to a cacti crop. “Farmers have to know a plant is going to make money before they’ll spend water on it,” Bañuelos explains – even if that plant is improving soil health.

Other plants also volatize salt and selenium, but none are as well suited to central California as prickly pear. Members of the broccoli family do well in moderately saline soils, but are too sensitive for the hot, dry weather of a San Joaquin summer. Australian saltbush loves salt, but cattle that eat it get so thirsty they'll drain water supplies. And there are a handful of what Bañuelos calls selenium-accumulator plants, but they absorb so much selenium that they could be toxic to wildlife.

Nopales farm, courtesy Flickr user Alitosan.

That leaves prickly pear. “The nastier the soil, the more exotic you have to go with your plant selection,” Bañuelos says. Yet before long, prickly pear may not seem so exotic at all. If other farmers take Diener’s lead – which isn’t farfetched, given his family’s well-established status in the area – the scraggly cactus could actually help save one of California’s last agricultural strongholds. It may not happen in time to pull struggling farmers out of the current drought, but as Diener knows, long-term survival in the agriculture business means constantly innovating.

“We’re running a big ship here,” he says of his 5,000-acre farm. “So it takes a while to turn. But we are turning.”

Krista Langlois is an editorial fellow at High Country News. She tweets @KristaLanglois2.