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Posts Tagged: water

Digging Deep: Exploring the diversity of soils in the Sacramento Valley

Participants gather around the first soil pit of the field tour, as Toby O'Geen provides a brief natural history of the land.

Not more than three months on the job and Konrad Mathesius is hard at work bringing farmers together to discuss the unique challenges that Sacramento Valley farmers face. As the new UCCE agronomy advisor for Sacramento, Solano and Yolo counties, his role is designed specifically to help growers with their crop issues – pests, disease and fertility – but with a strong background in soil science, Mathesius hopes to shed light on the diversity of soils in the region and the unique management considerations that each necessitates.

In hopes of highlighting this diversity of soils and encouraging growers to dig a little deeper to better inform their management practices, Konrad enlisted the help of UCCE soil resource specialist Toby O'Geen to lead a field tour of three major soils in the southern Sacramento Valley. The event included three pit stops on two Yolo County farms and brought out a diversity of participants from USDA Natural Resources Conservation Service agents, to resource conservationists, to farmers and crop advisors.

Kicking things off at Rominger Brother's Ranch -- a diversified family farm in Winters that grows everything from wine grapes to processing tomatoes to rice, wheat, corn, onions, alfalfa and hay -- O'Geen took the audience on a journey back in time, describing the rich natural history of the former floodplain that has given rise to the rich, productive soils that support California agriculture today. After introducing himself as a pedologist, or a scientist who studies the nature and properties of soil, he went on to introduce the five soil forming factors and their role in molding initial (1) parent material (i.e. rocks), under the influence of (2) climate, (3) topography and (4) organisms and over a given period of (5) time into soils. 

Yolo County farmers and UC Cooperative Extension specialist Toby O'Geen, right,peer deep into the processes that formed the land just beneath their feet.

Proving that soil scientists take the term “pit stop” literally, Mathesius shifted the conversation to a 1.5-meter deep hole in the ground, dug out the day before with a back hoe. Step by step, he walked participants through the process of analyzing a soil pit – cleaning the face, identifying horizons or individual layers and using the senses to assess soil properties and determine function. As he struck the face of the pit with a rock hammer, an audible difference was detected between the surface layers and the subsurface. 

Working backwards from the sound, he explained that the subsurface was significantly harder, which he attributed to a finer texture and ultimately identified as a clay pan, a restrictive layer that prevents roots from penetrating deeply and has the capacity to waterlog soils, due to poor drainage. O'Geen offered some tangible advice as to how to manage these soils, quipping that a deep rip would be no better than cutting butter with a knife (eventually it all just settles back into place) while likening a slip plow to a giant shank that just inverts the soil, mixing things to about a depth of 6 feet and permanently eliminating the problem.

UCCE agronomy advisor Konrad Mathesius, left, talks soil texture and water-holding capacity.

From there, Mathesius segued into a hands-on exercise to determine the soil texture, or percent distribution of various size particles, allowing participants to work on their pottery skills making balls and ribbons with the clay-rich soils.  Discussing the many functions that soil texture controls, led the conversation down a rabbit-hole around water holding capacity and how to calculate the range of plant available water for your soil.

With the demos out of the way, they voyaged to the next pre-dug pit, bringing participants face to face with the harsh reality of soil heterogeneity. Just 300 feet away and it was as if we had ventured into another environment altogether, yet these soils formed in the same place, under the same climate and similar vegetation, but in a completely different time with slightly different starting material.

By changing just a couple of the ingredients in the special sauce of soil formation the results are completely different featuring a clay dominant surface soil and entirely different water management challenges. And these aren't just any clays, but a special class that swell and shrink as they wet and dry, oftentimes shearing roots under the pressure and creating a hospitable environment for disease to thrive.  O'Geen suggested trying to keep them in the sweet spot where they are consistently moist, but not wet, and never allowed to dry out. Unfortunately, there is no precise measurement to that formula, “you just have to be almost like an artist. It's a lot of feel to it and the numbers sometimes just don't work out. It just comes with years of experience. Its one of those native intelligence things that you just have to feel your way through,” he noted.

Up close and personal with a soil pit, showing participants how to use basic tools of observation to assess soils!

Caravanning 20 miles back towards Davis, the tour arrived at the third and final pit, located at Triad Farms, a tomato operation in Dixon. Well-drained, young and fertile, Yolo loam soils are the poster children of agriculture, owing in large part to regular deposits of silts from past flood events. With not many management challenges to speak of, conversation immediately shifted towards an undocumented challenge that farmers on the eastern side of the Sacramento Valley are all too familiar with – the unavailability of potassium, even under intensive fertilization regimes. While the jury is still out on the cause and while it contradicts what soil scientists expect to find in those regions, possible explanations were tossed around and O'Geen used the opportunity to stress the importance of speaking up about things growers or advisors see going on in their area. Turns out the USDA-NRCS is working on updating its inventory of soil surveys, documenting soils across the nation and is currently seeking input on what's working for growers and where things are differing on the ground.

Ultimately, in closing, Mathesius called for more engagement between the university, extension and growers. O'Geen reminded everyone that “You can really learn a lot by digging a hole, looking at stuff, and developing theories.  Sometimes you're wrong, but they're kind of fun to talk about."

Posted on Monday, October 30, 2017 at 3:03 PM
Tags: geology (1), Konrad Mathesius (1), soils (1), Toby O''Geen (1), Water (93)

$1.6M from NSF to Study Water, Land Use in Disadvantaged Communities

The National Science Foundation has awarded $1.6M to UC Davis to analyze the complex relationships between surface water and groundwater supply, agricultural land use and the economic well-being of rural, disadvantaged communities.

The project is led by principal investigator Helen Dahlke, an associate professor in the UC Davis Department of Land, Air and Water Resources. The team will develop models to help guide decision-making regarding water management and land use in the state.

Helen Dahlke in field

Helen Dahlke studies how groundwater is used and replenished in California. (Tiffany Kocis/UC Davis)

While the newly funded project focuses on the Tulare Basin in California's Central Valley, it is expected to provide new insights for other regions of the United States facing similar issues involving economic and water security.

The broader impacts of the project focus on helping local disadvantaged communities participate in the governance of water resources. This includes forming “water schools” and engaging K-12 students from under-represented groups in science and policy issues.

The project will also provide interdisciplinary research education and training for graduate and undergraduate students, who will be involved in all aspects of the research and community engagement activities.

The project is supported by the NSF Dynamics of Coupled Natural and Human (CNH) Systems Program. The award is one of nine the program awarded across the nation this week, totaling $13 million.

“These awards demonstrate the importance of understanding the connectedness of nature and society in studying the effects of environmental change and socioeconomic stress,” said CNH program director Liz Blood of NSF.

Co-PIs on the research team include Jon Herman in the UC Davis Department of Civil and Environmental Engineering; Anne Visser and Clare Gupta in the UC Davis Department of Human Ecology; Rebecca Teasley from the University of Minnesota, Duluth; and Laurel Firestone from the nonprofit Community Water Center.

More information

Flooding Farms in the Rain to Restore Groundwater

Kat Kerlin writes about the environment for UC Davis Strategic Communications. Follow her at @UCDavis_Kerlin.

Posted on Thursday, September 14, 2017 at 8:27 AM
  • Author: Kat Kerlin
Tags: Clare Gupta (1), Helen Dahlke (2), Kat Kerlin (1), Water (93)

Future water leaders soak up irrigation information

University of California students are taking a long journey through California to trace the state's complicated and critical water supply. The recent graduates and upper-division co-eds from UC Merced, UC Santa Cruz, UC Berkeley and UC Davis are part of the UC Water Academy, a course that combines online training with a two-week field trip for first-hand knowledge about California water.

The tour began June 18 at Lake Shasta, the state's largest reservoir, and followed the water's course to the Sacramento Valley, through the Sacramento-San Joaquin Delta and south along the Delta-Mendota Canal. Since a key water destination is agriculture, the UC Water Academy toured the UC Kearney Agricultural Research and Extension June 23, where research is underway to determine how the state's water supply can be most efficiently transformed into a food supply for Americans.

Traveling in two vans, 10 students, a teachers' assistant and two professors are following the course of California water.

“You're visiting a place ideal for growing high-quality fruits and vegetables, because of the Mediterranean climate and low insect and disease pressure,” said Jeff Dahlberg, director of the UC KREC.

Kearney director Jeff Dahlberg leads a tour.

UC Cooperative Extension water management specialist Khaled Bali joined the students next to his alfalfa research plot, where different irrigation regimens are compared to determine the maximum yield that can be harvested with the minimum amount of water.

“It used to be that the No. 1 objective was to maximize yield,” Bali said. “But with the limited supplies and the cost of water, now the No. 1 objective is to get the maximum economic return. Growers might be better off selling some of their water to other jurisdictions.”

UCCE water management specialist Khaled Bali speaks about his alfalfa irrigation research.

A water tour wouldn't be complete without an introduction to drought research. A recently planted sorghum trial provided the backdrop.

“California is a great place to study drought tolerance,” Dahlberg said, “because you can induce a drought by withholding irrigation.”

UC Berkeley student Chelsee Andreozzi, right, asks a question while Tessa Maurer takes notes on a smart phone. UCB student Brian Kastl is in the background.

The sizable field contains 1,800 plots with 600 sorghum cultivars under three irrigation schemes: one irrigated as usual, one in which water is cut off before the plants flower, and the final one where water is cut off after the plants flower.

“Every week, a drone flies over to collect data on the leaf area, plant height and biomass,” Dalberg said. “Hopefully we will get associations with gene expression and this phenotype data."

Recently emerged sorghum that is part of a trial aiming to tease out the genes that express drought tolerance.

Dahlberg and his collaborating researchers believe identifying the genes responsible for drought tolerance in sorghum will help scientists find drought-tolerant genes in other cereal crops – such as wheat, corn, rice and millet. “This will go a long way to feeding the people of the world,” he said.

There is still much to learn about sorghum drought tolerance – is it conferred by the plant's waxy leaves, the way stomata are controlled, accumulation of sugar in the leaves, or a mechanism in the roots?

“These are all questions you will have to answer to feed the world,” Dahlberg said. “That's why I would encourage you to continue studying water. There's a lot for you to get into.”

Students gather in the post harvest laboratory at Kearney.

A third-year earth science student at UC Santa Cruz and a member of the academy, Denise Payan, said the sense of responsibility for the future is not daunting, but encouraging.

“It makes me feel like I can make a difference,” she said. The tour through California is shaping her plans for the future, which may include a career at the intersection of geology and biology.

“This has opened my eyes to a lot of issues,” she said.

The next stop for the UC Water Academy is the vast Tulare Lake basin to learn about groundwater recharge before heading east to the Owens Valley and the shores of Mono Lake. From there the academy turns to the Sierra Nevada to visit San Francisco's water supply, which is collected by Hetch Hetchy Dam. The field trip ends with a two-day rafting trip on the American River.

The UC Water Academy is offered through UC Water and led by UC Merced professor Joshua Viers and UC Cooperative Extension water management specialist Ted Grantham. In addition to the two-week tour, students participated in weekly online meetings and complete a project on communicating California water issues to public stakeholders. Students receive 1 unit of academic credit.

Posted on Friday, June 23, 2017 at 2:29 PM
Tags: Jeff Dahlberg (1), Khaled Bali (2), water (93)

UC water institute announces 2017 grant recipients

The UC California Institute for Water Resources (CIWR) has announced the recipients of six grants to address the most critical water issues in the state. For this program, the Institute leverages funds it receives from the Water Resources Research Act of 1964 through the Department of Interior.

CIWR, which is part of UC Agriculture and Natural Resources, facilitates collaborative research and outreach on water issues across California's academic institutions and with international, federal, state, regional, nonprofit, and campus communities.

Small grants to support initial work will be dispersed to the following projects (click the headline for more information):

Farmer Jim Morris on an alfalfa field being flooded for groundwater recharge.

Suitability of alfalfa for winter groundwater recharge
Helen Dahlke, professor in the Department of Land, Air and Water Resources, UC Davis
One proposed solution for recharging overdrawn aquifers is flooding farmland during the rainy season. Optimizing agricultural groundwater banking for specific crops can be challenging. The goal of this project is to better understand how alfalfa, which is grown year-round, responds to winter flooding.

Fish habitat response to streamflow augmentation
Ted Grantham, UC Cooperative Extension specialist in the Department of Environmental Science Policy and Management, UC Berkeley
Declining water levels can degrade or eliminate fish habitat during California's summer season. Storing water off-channel during the rainy season can improve flow during the summer. The study is designed to gain a better understanding of the relationship between stream flow and habitat.

Remote sensing of turfgrass response to irrigation
Amir Haghverdi, UC Cooperative Extension specialist in the Department of Environmental Science, UC Riverside
Turfgrass is common in urban landscapes and provides valuable recreation areas and ecosystem services. This project will help determine the best irrigation strategies for common turfgrass species.

UC Santa Cruz professor Eric Palkovacs in the field.

Habitat restoration impacts on water management
Eric Palkovacs, professor in the Department of Ecology and Evolutionary Biology, UC Santa Cruz
The natural conditions of the Sacramento-San Joaquin Delta have been changed by habitat alteration and non-native predacious fish introduction. This project will examine the interplay between altered habitat and predatory fish, and how they impact native salmon populations.

Evaluating water conservation policy in California
Leah Stokes, professor in the Department of Political Science, UC Santa Barbara
During the recent drought, California required that on-average urban water districts conserve 25 percent of their water. While some districts were successful, others failed to meet their target. This project will examine how variation in policy – pricing, messaging and penalties – and drought severity affected water conservation.

Sacramento State geology professor Amelia Vankeuren and graduate students collect samples at the American River.

Groundwater dynamics after California drought
Amelia Vankeuren, professor in the Department of Geology, Sacramento State University
As part of California's groundwater management act, some basins were designated as high management priorities. This project will characterize groundwater using age, location and temperature. This information will be valuable for stakeholders creating a groundwater sustainability plan.

Posted on Monday, March 13, 2017 at 9:27 AM
Tags: CIWR (1), grants (1), water (93)

Canyon Classroom: Exploring the Grand Canyon's plants along the Colorado River

While some people were spending spring break at the beach or catching up on their Netflix queue, students from the EcoGeoMorphology class at UC Davis were rafting down the Colorado River at the bottom of the Grand Canyon.

[Join the journey: UC Davis Grand Canyon interactive website, http://grandcanyon.ucdavis.edu.]

The class split in two groups for the 225-mile river journey. On March 10, the group embarked from Lee's Ferry, rafting 90 miles before hiking to the rim on March 19 along Bright Angel Trail. They passed the second group on their way down the same day. They traveled the remaining 135 miles to the next road access at Diamond Creek. 

The class is conducted during winter quarter by the Department of Earth and Planetary Sciences and the Center for Watershed Sciences, in partnership with Campus Recreation's Outdoor Adventures. While its first trip to the Grand Canyon was in 2003, students have taken this optional trip for each of the past five years.

Truman Young, Sarah Yarnell and Sasha Leidman begin another day on the Colorado River in the Grand Canyon. Credit: Joe Proudman/UC Davis

Among the class' instructors this year was UC Davis plant sciences professor and UC Agriculture and Natural Resources affiliate Truman Young.

‘There's nothing quite like this'

The trip is the physical and visible representation of what the class is all about: Geologists, hydrologists and ecologists learning to communicate with each other and the public. It's a skill necessary in real-world careers, where working on environmental problems requires a variety of expertise that isn't always taught in siloed classrooms.

“I'm not a geologist myself, but you only have to look left to right at any moment, and there's nothing quite like this,” said Young while floating down the river, taking in the cliffs rising around him.

The classrooms are pretty spectacular: red walled caverns, ancient Puebloan ruins, rock formations and fossils, the river itself. It's the students' textbooks brought vividly and tangibly to life.

Along the way, Young described the life cycle of Century plants; explored the plants sprouting around Vasey's Paradise, a natural spring; and rubbed scale insects off prickly pear plants to expose the crimson dye they produce. At each step, he casually prodded the students to consider what it means to have a river running through a desert.

Truman Young points out a Century plant in the Grand Canyon to UC Davis students. Credit: Kat Kerlin/UC Davis

Time travelers

The group was unplugged, off-grid, and literally immersed in the river, rocks and landscape.

Geologists, ecologists, and hydrologists helped teach each other about rocks, plants, fish and flow rates—usually informally as they scrambled up a trail or gazed up at the vertical cliffs slowly floating past.

Truman Young talks to UC Davis students in the Grand Canyon. Credit: Joe Proudman/UC Davis

They slept each night under a sky bright with forgotten stars, to the sounds of softly strumming guitar and the nearby rushing river. 

Over the course of eight days on the river, they traveled through about a billion years of geologic time.

Young had been on the trip once before, two years ago. He said it was just as impressive the second go-around.

“It's actually more spectacular on the second pass, which surprised me,” he said. “Just the magnitude and the grandeur of it, all that stuff. It's just more.”

Posted on Wednesday, August 3, 2016 at 8:44 AM
Tags: Canyon (1), Colorado (1), Davis (1), Desert (1), Ecogeomorphology (1), Grand (1), Plant (1), River (1), Sciences (1), Truman (1), UC (1), Water (93), Young (1)

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