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Posts Tagged: soil

SoilWeb reveals what's hidden underneath the ground's surface

Anthony O'Geen in the Mojave Desert.
Beneath your home, below lawns, under asphalt streets, farms and natural areas there is a complex blend of minerals and organic matter that varies widely in texture, color and structure. Producing food, maintaining landscapes and building structures all depend on this little understood, but critical outermost layer of the Earth’s crust - the soil.

Anyone can learn about the United States’ diversity of soils using SoilWeb, a nationwide database of soil variability first developed in 2004. SoilWeb reached a new milestone this year when it was integrated with Google Maps and designed to scale across any Web-enabled device – desktop computer, tablet or smart phone.

SoilWeb has dozens of uses. The information can inform insurers about flooding frequency and builders about locations suitable for roads, basements or septic tanks. The agricultural real estate industry, farmland owners and farmers interested in renting or purchasing land commonly need information about soil productivity and land capability. Knowledge of soil is also important to home gardeners and landscapers.

“SoilWeb’s a great way to understand the landscape you live in,” said Anthony O'Geen, UC Cooperative Extension specialist in the Department of Land, Air and Water Resources at UC Davis. O’Geen developed SoilWeb with Dylan Beaudette, now a Natural Resources Conservation Service soil scientist, when Beaudette was a Ph.D. student at Davis.

The SoilWeb allows users to find information about the soil at a location by standing at the site with a GPS-enabled smart phone or tablet or by entering an address, landmark or latitude and longitude coordinates for anywhere in the United States. The location’s satellite image opens overlaid with yellow polygons marking soil-type boundaries. For each of the polygons SoilWeb provides information about soil profiles, soil taxonomy, land classification, hydraulic and erosion ratings and soil suitability ratings.

For example, the soil under Disneyland in Anaheim is 80 percent Metz loamy sand, characterized as very deep, somewhat excessively drained soil that formed in alluvial material from mixed, but dominantly sedimentary rocks. This is likely of great interest to the Imagineers who are responsible for maintaining the theme park’s extensive landscaping.

All the soil information in SoilWeb was collected from the National Cooperative Soil Survey, organized by the Natural Resources Conservation Service. NRCS began collecting the information in the 1930s.

“The surveyors create a conceptual model of the distribution of soils and soil properties by digging holes, conducting field tests and characterizing representative soils in the laboratory,” O’Geen said. “Not all soil survey areas are the same. Areas such as agricultural regions have more detailed information compared to cities. Because they started so early, they never dreamt of the intended uses of the land and demands required of soil surveys. Today, our methods of collecting data have become much more rigorous and new surveys of urban landscapes are much improved.”

The soil survey reaches about five feet below the surface or to bedrock, O’Geen said. One shortcoming of the database is in some urban areas the soil is classified simply as “urban land.” Where the California State Capitol is situated in Sacramento, for example, the locale is considered 100 percent urban land. No other information is given.

“That’s unfortunate,” O’Geen said. “They are changing that. Surveyors are remapping critical areas, but it’s tough. You can’t dig holes easily in cities.”

In addition, on some rugged terrain in the West, surveys haven’t yet been completed, including parts of the Mojave Desert, Calaveras and Tuolumne counties.

“Soil survey is one of the most detailed and expansive spatial data sets in the world,” he said. “It’s a tremendous resource that has helped our nation conserve and carefully manage soil and water resources.”

Find SoilWeb at http://ucanr.edu/SoilWeb.

The Magic Kingdom on SoilWeb (http://ucanr.edu/soilweb).
The Magic Kingdom on SoilWeb (http://ucanr.edu/soilweb).

Posted on Thursday, May 16, 2013 at 8:29 AM
Tags: Anthony O''Geen (2), soil (9), SoilWeb (1)

Russell Ranch digs deep

Approximately every ten years, the research team at the Russell Ranch Sustainable Agriculture Facility at UC Davis gets the chance to dig deep into their research material to help answer questions about the long-term sustainability of agricultural systems. 

With a steel probe attached to the back of a tractor, the team digs three meters deep to take soil samples at 432 different points around the 72-acre field. The initiative takes the team nearly a month to complete, and the information in each soil core can answer major research questions about the long-term effects of different farming methods on soil health and help inform year-round research efforts at the ranch.

“The effort that has gone into collecting this unique set of samples will pay off in figuring out agricultural impacts on processes happening not only in plain sight, but also out of view, buried deep in the soil,” said Russell Ranch director Kate Scow

The sampling effort is part of the Century Project, Russell Ranch’s 100-year-long experiment. The project divides 72 acres of land into individual one-acre plots, with each plot given different treatments throughout the year. Some plots are irrigated; other plots are farmed without added water. Some plots are treated with compost; others are treated with synthetic fertilizer. Each individual plot demonstrates how a combination of different practices can affect crop yield, soil health and the health of surrounding ecosystems. 

The 10-year sampling is a comprehensive look at the system, meant to serve as a baseline in determining the soil health at Russell Ranch. And there are a lot of factors that influence soil health. The research team tests for changes in soil organic matter, organic nitrogen, phosphorous, and other elemental content. They also test for bulk density (the amount of compaction in the soil), moisture content, and the microbial community at different soil depths.

Too, the soil sampling efforts dig deeper in the soil than much research, bringing important new information to soil science. 

“Historically, much of the research has focused on the top 15 to 30 centimeters of soil. Some previous ideas about the distribution of carbon in the soil and effects of tillage on soil health have been wrong because of this,” said Scow.

With the Century Project in its 19th year, the 2012 soil samples are the third out of 11 field-wide samples to be taken over the course of the project. Changes to soil can happen slowly, so a long-term focus allows researchers to update their research as new information and new technologies become available.    

“The big questions scientists are asking have changed, so we’re hoping to implement a new set of research questions that will drive us for the next 20 years,” said Emma Torbert, post-graduate fellow at Russell Ranch. “The benefit of long-term research is that we are provided the time to respond to those changing questions.”

Taking a soil sample at UC Davis' Russell Ranch.
Taking a soil sample at UC Davis' Russell Ranch.

Posted on Friday, November 30, 2012 at 8:28 AM

Understanding soil erosion in irrigated agriculture

Soil erosion threatens our ability to feed ourselves in the future. Current concerns regarding soil erosion include economic vitality, environmental quality and human health.

How can losing a little soil to erosion be such a concern? Soil formation is a very slow process. It takes nature between 300 to 1,000 years to replace soil lost over a 25-year period at a loss rate of 1 mm per year (25 mm is approximately 1 inch)

Erosion reduces the productivity in several ways: Plants are not able to use nutrients as efficiently, seedlings are damaged, rooting depth is decreased, soil’s water-holding capacity is diminished, permeability is decreased, runoff increases and the infiltration rate declines.  The loss of healthy soil leads to poor plant growth and lower crop yields.

In the United States we lose an estimated 6.9 billion tons of fertile topsoil to erosion each year. Losses of this size are far from sustainable. In an effort to continue food production, costly fertilizers and amendments are used to compensate for the lost soil. The loss of nutrients alone is estimated to cost U.S. farmers $20 billion a year.

As runoff carries sediment, nutrients, and agricultural chemicals off-site, the economic and environmental costs skyrocket.

The University of California has resources to help reduce the loss of soil through erosion. The free, five-page publication Understanding Soil Erosion of Irrigated Agriculture provides information to help maintain the productivity of land and reduce the enormous costs associated with erosion.

Topics include:

  • Impacts of soil erosion
  • Types of water erosion
  • Indicators of soil erosion
  • Soil survey interpretations
  • Land capability classification system
  • Soil erosion factors
  • New soil survey resources

Additional resources, can be found at the UC ANR free publication website.


Soil erosion from water runoff in avocado grove. Deep gully eroded in steep slope. Trees are growing among bare soil. Photo by David Rosen.
Posted on Wednesday, August 24, 2011 at 8:09 AM
  • Author: Chris M. Webb
Tags: erosion (4), soil (9)

Want to report SOD? We’ve got an app for that!

When the great outdoors is your research laboratory, gathering data can be a challenge. To get a broader perspective on the extent of damage caused by sudden oak death, a UC Berkeley Cooperative Extension geographer is using crowd sourcing to enhance her research on the disease that has killed over a million of California’s iconic oak trees since 1995.

Maggi Kelly, UC Berkeley Cooperative Extension specialist, started collecting data from community members through her OakMapper website in 2001. Now she has a mobile application for smartphones


While out in a park or forest, iPhone users can use the new OakMapper mobile app to report sightings of trees killed by Phytophthora ramorum, the plant pathogen that causes SOD. Onsite, participants can note the symptoms they see, such as seeping, bark discoloration, crown discoloration, dead leaves, shoot die-back, fungus, beetle frass and beetle bore holes.

The OakMapper app, created by scientists in the UC Berkeley Geospatial Innovation Facility, uses the phone's built-in GPS to identify the participant’s location when the data is submitted.

They also can describe the environmental setting, such as residential landscape or natural forest.

“Many of the challenging natural resource problems that we face today – like invasive species, fire, climate change – are large in spatial scale and impact diverse public groups,” said Kelly, director of the UC Berkeley Geospatial Innovation Facility. “Addressing these challenges often requires coordinated monitoring, efficient data collection, and increased communication and cooperation between scientists and citizens.

Science can benefit from your powers of observation. We all benefit by becoming informed about problems such as sudden oak death.

If you are like me, a person who sometimes doesn’t recognize coworkers outside the office, you may choose a spectator role. You can use the app to look at the maps to see where SOD is taking down trees.

For more information about OakMapper and its app, visit oakmapper.org. The OakMapper app can be downloaded for free from the iTunes app store.

I’ve heard of two other apps developed at UC to collect natural resources-related data from other scientists and interested members of the public.

You can use UCLA’s What’s Invasive apps to report locations of top invasive plants and animals, which compete with California’s native fauna and flora. By submitting location data and setting up top invasive lists for your area, you can assist scientists monitoring the spread of the destructive invasive plants and animals. Images and brief descriptions in the app help with identification. The apps are free and available for the Android and iPhone.

Soon you will be able to report roadkill sightings on your iPhone. The UC Davis Road Ecology Center has submitted to the iTunes store an iPhone app for reporting roadkill. Until the app becomes available sometime in January, you can report your observations to the California Roadkill Observation System via the Web at http://roadecology.ucdavis.edu/CROS.html.

Another cool app has been developed by the UC Davis Soil Resource Laboratory to deliver information to scientists, growers and gardeners about the properties of their soil. While standing in the field, the user can receive location-based information on a GPS-enabled cell phone. The app is available for free for iPhone and Android OS platforms.

Which science-related apps are you using? You can share them in the comments section or e-mail me at pskanrice@ucdavis.edu.

Posted on Wednesday, December 22, 2010 at 6:33 AM
Tags: apps (2), invasive species (12), Maggi Kelly (5), roadkill (3), soil (9), sudden oak death (7)

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