Calculating New Options for Shrinking Rice Fields

George Tibbitts, a third-generation farmer in Arbuckle, CA, has been growing rice on his 1,200-acre farm for three decades. His Sacramento Valley irrigation district, one of the oldest in the state, has long benefitted from senior water rights, which date back to 1914. The rights allow farmers such as Tibbitts to keep their fields flush with water, even in arid conditions.

But last year, with much of the state in extreme drought, he faced a career first: His district slashed water allocations by an unprecedented 90 percent, leaving him with little choice but to fallow all of his rice fields.

Fortunately, the tenth of normal supply he received was still enough to plant sunflower, wheat and tomatoes in four of his nine fields. “If I were only growing rice,” says Tibbitts, “I would’ve been in a big world of hurt.”

Because farming is a profession fraught with uncertainty, there are obvious advantages to having options. Yet, when it comes to rotating fields in a region steeped in a long tradition of growing rice, Tibbitts goes against the grain. In fact, only about 10 percent of the Sacramento Valley’s 500,000 acres of riceland is rotated, with heavy clay soils favoring flooded paddies over other field crops. As such, there’s little information or much of a history to support the practice of crop rotation or substitution.

To bridge the knowledge gap, University of California researchers have developed the Rice Rotation Calculator, an online tool that helps growers explore the economic impacts of switching from rice to one of several alternative crops. Like an insurance estimator, it takes the guesswork out of field rotation: Farmers input a host of variables for cultivating rice—everything from seed and input costs to equipment, labor and irrigation—to get instant, dollar-per-acre revenue comparisons for beans, safflower, sunflower and tomatoes.

Crop rotation can help mitigate the economic and agronomic risks of mono-cropping, such as loss of soil fertility, increased reliance on pesticides and vulnerability to price fluctuations, says Whitney Brim-DeForest, a UC Cooperative Extension rice advisor, who developed the calculator with Sara Rosenberg, a UC Davis doctoral student in horticulture and agronomy.

However, because the practice is relatively rare in California’s rice country, the unknowns can make it a daunting proposition. “We don’t want to advise [growers] to crop-rotate if they [don’t] have an idea of what it looks like economically,” says Brim-DeForest. “This tool is designed to help them make informed decisions and, hopefully, reduce the barrier to entry.”

There’s also an enormous effort required to take a field out of rice, including removing levees, bedding up fields and installing irrigation. Rosenberg says that’s just one factor that contributes to “a whole system that’s been created to make rice so feasible.” Yes, there’s the clay soil, flat landscape and senior water rights. But that has created a unique regional economy and industry—one that seeds fields with planes instead of drill seeders, harvests with giant combines rather than tractors and requires far less labor than row crops.

It’s no wonder, then, that there’s very little data to support the practice of rotating rice fields, adds Brim-DeForest, and a lot of uncertainty around adopting such a major transition. “In this region, rice is a cultural crop,” she says—one engrained throughout generations of families and entire communities. The ubiquity often means that information and resources needed to make a switch are harder to come by, as are the social networks that aid in sharing equipment and tapping different markets.

The Rice Rotation Calculator is designed to demystify one of the biggest unknowns of rotating out of rice: the bottom line. Curious growers simply input their current farming costs as well as opportunity costs—the learning curve, in hours, for a new cropping system multiplied by hourly wage—to get a comparative overview of switching to one of four options: dry beans, safflower (both lower in value than rice, with a low barrier to entry), sunflower or tomatoes (both higher in value, with a more complicated transition).

Data pulled from the UC Integrated Pest Management Program, which developed the backend, factors in a comprehensive range of cost considerations. Along with seed, input and equipment costs, the calculator accounts for labor, field reconstruction and even rent for tenant farmers. Users get instant rice-versus-selected-crop comparisons, displayed via a graph and itemized summary for first- and average-year costs and net revenue.

Rosenberg emphasizes that the calculator shows only short-term cost implications, and it doesn’t account for bumps in rice yields, savings in inputs and weed control and additional benefits touted by Tibbitts and other advocates. She hopes that in supporting the wider adoption of crop rotation, data and research will follow and that future upgrades will incorporate that knowledge into forecasting long-term returns on a seemingly promising investment.

In the meantime, the calculator allows growers to weigh sound options for squeezing the most out of a limited water allocation or selecting a robust crop mix for weathering a cool rice market. Given all the uncertainties inherent in farming,“it’s another tool in the toolbox,” says Rosenberg, for growers to build resilience.

In a normal year, the Sacramento Valley produces 97 percent of California’s rice, but with reservoirs drained after three years of continuous drought, production plummeted by half in 2022, to 250,000 acres. Although heavy winter storms have brightened the outlook for this year, “we’re not out of the woods yet,” says Tibbitts. The U.S. Bureau of Reclamation recently signaled a potential increase in allocations—all the while noting that conditions are still subject to change. At this point, he notes that he’d be happy to get half of his annual water supply.

Regardless of outcome, a diverse planting helps Tibbitts roll with the punches. While four fields are slated for a May seeding of rice, he’ll plant a couple with sunflowers in early spring and lease the remainder to a tomato grower. In addition to stretching water allocation—sunflowers grow solely on residual soil moisture, while drip-irrigated tomatoes require 60 percent less water than rice—crop rotation improves soil health, reduces pesticide resistance and weeds and helps stagger his harvest.

“And when I put a field back into rice after growing tomatoes,” adds Tibbitts, “I always get the best yields.”

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Ramón Mendez Larrosa

1 year ago

Very weel