Please continue to read the research article in full HERE.
Soil suitability index identifies potential areas for groundwater banking on agricultural lands7/17/2018 by A.T. O’Geen, Matthew B.B. Saal, Helen Dahlke, David Doll, Rachel Elkins, Allan Fulton, Graham Fogg, Thomas Harter, Jan W. Hopmans, Chuck Ingels, Franz Niederholzer, Samuel Sandoval Solis, Paul Verdegaal and Mike Walkinshaw Groundwater pumping chronically exceeds natural recharge in many agricultural regions in California. A common method of recharging groundwater — when surface water is available — is to deliberately flood an open area, allowing water to percolate into an aquifer. However, open land suitable for this type of recharge is scarce. Flooding agricultural land during fallow or dormant periods has the potential to increase groundwater recharge substantially, but this approach has not been well studied. Using data on soils, topography and crop type, we developed a spatially explicit index of the suitability for groundwater recharge of land in all agricultural regions in California. We identified 3.6 million acres of agricultural land statewide as having Excellent or Good potential for groundwater recharge. The index provides preliminary guidance about the locations where groundwater recharge on agricultural land is likely to be feasible. A variety of institutional, infrastructure and other issues must also be addressed before this practice can be implemented widely.
Please continue to read the research article in full HERE.
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As general manager of a water district that serves about 27,000 agricultural acres in the southern San Joaquin Valley, Eric Averett knows the solutions to the region’s water shortages are fairly straight-forward.
He speaks of two knobs that valley water users can turn. One controls supply, and the other demand. In past years, Averett says he figuratively had his hand slapped by his Rosedale-Rio Bravo Water Storage District board whenever he tried to adjust the knob that affected the supply of water to growers. But as droughts, surface water cutbacks and groundwater overdrafts confront districts throughout the Central Valley, all solutions are now on the table. “Throughout the valley, we’re going to end up turning both knobs in the future,” Averett said during a recent panel discussion on the valley’s water future. In short, experts believe the only way to bring the valley’s overburdened water supplies into balance will be to increase supply, mainly by making the most of available water, and reduce demand. And part of reducing demand may well be the voluntary fallowing of agricultural land. “For some of our hardest-hit areas, the idling of agricultural land is going to be a reality,” says Abbey Hart, the agriculture project director for The Nature Conservancy. She adds that growers may see an economic benefit for converting land into wildlife habitat, but the process will have to be well planned. A checkerboard approach to creating habitat won’t work, she says. “A lot of these species won’t be able to use tiny patches of land,” Hart told about 200 growers and others at the water forum in early May, sponsored by the Almond Board of California. Please continue to read in full HERE. Agriculture could pull carbon out of the air and into the soil — but it would mean a whole new way of thinking about how to tend the land. By Moises Velasquez-Manoff for the New York Times | April 18, 2018 hen John Wick and his wife, Peggy Rathmann, bought their ranch in Marin County, Calif., in 1998, it was mostly because they needed more space. Rathmann is an acclaimed children’s book author — “Officer Buckle and Gloria” won a Caldecott Medal in 1996 — and their apartment in San Francisco had become cluttered with her illustrations. They picked out the 540-acre ranch in Nicasio mostly for its large barn, which they planned to remake into a spacious studio. Wick, a former construction foreman — they met when he oversaw a renovation of her bathroom — was eager to tackle the project. He knew the area well, having grown up one town away, in Woodacre, where he had what he describes as a “free-range” childhood: little supervision and lots of biking, rope-swinging and playing in the area’s fields and glens.
The couple quickly settled into their bucolic new surroundings. Wick began fixing leaks in the barn. Rathmann loved watching the many animals, including ravens, deer and the occasional gopher, from the large porch. She even trained the resident towhees, small brown birds, to eat seed from her hand. So smitten were they with the wildlife, in fact, that they decided to return their ranch to a wilder state. For nearly a century, this had been dairy country, and the rounded, coastal hills were terraced from decades of grazing. Wick and Rathmann would often come home and find, to their annoyance, cows standing on their porch. The first step they took toward what they imagined would be a more pristine state was to revoke the access enjoyed by the rancher whose cows wandered their property. Within months of the herd’s departure, the landscape began to change. Brush encroached on meadow. Dried-out, uneaten grass hindered new growth. A mysterious disease struck their oak trees. The land seemed to be losing its vitality. “Our vision of wilderness was failing,” Wick told me recently. “Our naïve idea was not working out so well.” Wick was especially bothered by the advance of a prickly, yellow-flowered invasive weed called the woolly distaff thistle. He pulled it, mowed it, doused it with herbicides. But the distaff kept moving into what had been pasture. He thought about renting goats to eat the weeds and brush, but they were too expensive. He even considered introducing wild elk, but the bureaucratic hurdles seemed too onerous. Then Wick and Rathmann met a rangeland ecologist named Jeff Creque. Instead of fighting against what you dislike, Creque suggested, focus on cultivating what you want. Squeeze out weeds by fostering conditions that favor grasses. Creque, who spent 25 years as an organic-pear-and-apple farmer in Northern California before earning a Ph.D. in rangeland ecology, also recommended that they bring back the cows. Grasslands and grazing animals, he pointed out, had evolved together. Unlike trees, grasses don’t shed their leaves at the end of the growing season; they depend on animals for defoliation and the recycling of nutrients. The manure and urine from grazing animals fuels healthy growth. If done right, Creque said, grazing could be restorative. Please continue to read in full at The New York Times. Summary and Conclusions from SRT’s San Joaquin Valley Greenprint Demonstration Project
The State of the Valley Report identifies water as “one of the central management challenges of the San Joaquin Valley,” and emphasizes that “[b]oth surface water and water pumped from underground aquifers are critical to the region’s farming, ranching, urban users, industry, and natural ecosystems.”[1] Implementation of the Sustainable Groundwater Management Act (SGMA) is just beginning,[2] but the overall dialogue about water sustainability has focused more on technological solutions than on ways to improve the natural ability of watersheds to absorb, store and gradually release water in forms useful to people and the land. Sequoia Riverlands Trust’s (SRT’s) San Joaquin Valley Greenprint Demonstration Project explores the potential contribution of land-based strategies to watershed effectiveness, usable water supply and groundwater sustainability, focusing on three themes:
These approaches are not new. Many have been extensively researched, incorporated into funding programs and regulatory requirements, and applied to varying degrees.However, relatively little attention has been paid to the relationship of these land-based strategies to effective watershed function and groundwater sustainability. Sequoia Riverlands Trust applied existing Greenprint data and other information to map areas where these approaches might yield the greatest water-related benefits, and to roughly quantify their potential contribution to groundwater sustainability in the Kaweah and Tule River Watersheds. Our results suggest that practical applications of these strategies could offset at least 25% of the annual groundwater deficit in the Kaweah and Tule River Watersheds by addressing both the supply and demand sides of the water balance equation. This assertion is based on estimates that:
Furthermore, all of these land-based strategies provide additional ecological, economic and community benefits, such as increased agricultural production, flood management, habitat enhancement, drought resilience and aesthetic values, that make them politically palatable alternatives to new dams or regulations about water use. Water-focusedland conservation, restoration and management strategies therefore deserve serious consideration as we work together to solve our region’s pressing groundwater sustainability concerns. [1]Thorne et al., 2014. [2] Cal. Water Code § 10720 et seq. Please view the project PowerPoint presentation HERE. Sustainable California Premiere Date: 5/5/2017 | from University of California Television How researchers at UC Merced are developing a better understanding of the three sources of water upon which California depends in order to adapt to the effects of environmental changes and make better use of this most precious of our natural resources. |
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