California is suffering historic drought conditions. The information on this webpage offers farmers and ranchers links to valuable resources, carried out by researchers and specialists, on a vast array of issues they are facing during this extremely dry and difficult year. For general drought information please click on the links below.
For drought issues with a particular crop, please see the left navigation buttons where you will find resources for your specific agricultural needs.
UC ANR California Institute for Water Resources Drought Information
UC Davis Rangeland Watershed Laboratory Managing Drought http://rangelandwatersheds.ucdavis.edu/main/drought.html#RancherPerspectives
Coping with Declining Groundwater Levels
CIMIS Drought Tips
View film excerpts from University of California Researchers and Academics on a large variety of expert water and drought topics
Insights: Water and Drought Online Seminar Series
Irrigation Scheduling Tools
UC Drought Management-Evapotranspiration Scheduling
Soil Moisture Monitoring
UC Drought Management-Soil Moisture Monitoring
Irrigation Scheduling during a Drought
John Letey, Jr.
University of California–Riverside (UCR) Distinguished Professor of Soil Physics and Soil Physicist Emeritus John Letey, Jr. passed away on 14 September. He was 81 years old.
He received his B.S. degree at Colorado State University and Ph.D. degree at the University of Illinois. He joined the faculty in the Department of Irrigation and Soil Science at UCLA in 1959, but with the phasing out of agriculture at UCLA, he elected to join the Department of Soil Science at UCR in 1961 and enjoyed a distinguished career in research, teaching, administration, and service at the university. During his tenure, Dr. Letey served as chair of the Department of Soil and Environmental Science from 1975 to 1980, director of the Kearney Foundation of Soil Science from 1980 to 1985, and director of the University of California Center for Water Resources from 1999 to 2003. He was instrumental in the establishment of the Environmental Sciences undergraduate major at UCR, which was one of the first of its kind in the United States. He recognized and appreciated the critical link between science and policy and built teams and research to address it.
Letey's research focused on all aspects of water quantity and quality related to irrigated agriculture that provided both applied and basic information critical to establishing sound water resource management. Topics of research included irrigation, drainage, salinity, pesticide transport, plant–water relations, nitrogen, soil aeration, and polymers. He was also recognized as one of the world authorities on water-repellent soils and the utilization of surfactants. He wrote a biography of his education and professional career that can be accessed on the following website: http://envisci.ucr.edu/downloads/johnleteycareer.pdf.
Letey was a fellow of SSSA, ASA, and AAAS and was awarded the SSSA Soil Science Distinguished Service Award in 2005 and the SSSA Soil Science Research Award in 1970. He authored or co-authored more than 300 technical publications concerning chemical, water, and gas movement through soil before retiring from UCR in 2002. In 2007, he published a fictional book titled, The Folly of Fearing Death (PublishAmerica, Baltimore).
In 2003, Letey and Ardyth Stolzy, wife of the late Professor of Soil Physics Emeritus Lewis H. Stolzy, combined the Letey Soil Environmental Fund and the Lewis Stolzy Memorial Fund into the Stolzy–Letey Endowment in Soil and Environmental Science. The Stolzy–Letey Fund is now used for the benefit and support of the students in the Department of Environmental Sciences at UCR.
Letey was a friend and mentor to students, visiting scholars, and faculty across the world. He served his research community, church, and family with great love and personal integrity. He is survived by his wife, Sonia; three children, Laura Petersen, Don Letey, and Lisa Smith; 10 grandchildren; and 11 great-grandchildren./h3>
Impacts of the recent drought conditions on Central Coast avocado production, and potential impacts of continued drought conditions
Avocados are the most salt and drought sensitive of our fruit tree crops. They are shallow rooted and are not able to exploit large volumes of soil and therefore are not capable of fully using stored rainfall. On the other hand, the avocado is highly dependent on rainfall for leaching accumulated salts resulting from irrigation water. In years with low rainfall, even well irrigated orchards will show salt damage. During flowering there can be extensive leaf drop due to the competition between flowers and leaves when there is salt/drought stress. In order to reduce leaf damage and retain leaves, an excess amount of water is required to leach salts out of the roots zone. The more salts in the water and the less rainfall, the greater leaching fraction. Drought stress often leads to diseases, such as black streak, bacterial canker, and blight (stem, leaf, and fruit). Defoliation leads to sunburned trees and fruit which can be severe economic losses.
Strategies to address drought conditions
Ensure that the irrigation system is at its greatest potential and is maintained. Avocados are grown on hillsides and pressure regulation is extremely important and is frequently neglected.
Significantly prune trees to reduce leaf area. Avocado can be a very large tree, and if half the canopy is removed, there can be as much as 1/3 reduction in water use. When trees are about 15 feet tall, removing half the canopy can reduce water use by one half.
In extreme drought conditions, the canopy can be reduced to just the skeleton branches which are white washed to prevent sunburn. Water use drops to zero, and then gradually as the tree leafs out, water can be slowly reapplied, but at significantly less amounts than with the full canopy. Stumping typically results in three years' worth of crop.
In orchards that have low producing areas, because of recurrent frost, high winds, shallow soils, disease, etc. the grower could decide to completely remove those trees, thereby saving water.
White kaolin applied to leaves has been shown to reduce leaf temperatures and water loss. This can be used, but under the direction of the packing house, since if it is applied to fruit, it is very difficult to remove.
Impacts of the recent drought conditions on Central Coast citrus production, and potential impacts of continued drought conditions
Citrus is much less sensitive to salts and drought than avocado, partially because of its greater rooting depth. However, it is much more sensitive than deciduous fruit trees, resulting in smaller fruit and lower prices when drought cannot be addressed with adequate irrigation water. Drought also makes the trees more susceptible to leaf drop, and sunburned fruit.
Strategies to address drought conditions
The strategies for citrus are very similar to those for avocado. It is much more sensitive to pruning to reduce water use than avocado. Typically removing half the canopy results in half the water use. Because of thus greater control, citrus is rarely stumped.
By reducing canopy size, production can be maintained, often without loss of fruit size.
Kaolin clay can effectively reduced water use and can be applied soon after harvest without the problem of coating fruit making its removal difficult at the packing house.
California Drought Watch
Although water is in short supply, UC Davis' expertise in water-related issues is not. California Drought Watch brings together the university's globally renowned resources in water sciences, management, law and agriculture to ensure that policymakers and the general public have access to the knowledge, research and technologies that are crucial to addressing the challenge of the state's drought.
Visitors to the site will find the latest drought research and news headlines, as well as drought management tools from UC Davis experts and water organizations throughout the state. They will discover how UC Davis is cutting back on water consumption, learn about upcoming events like the April 25 Drought Summit, and find out how to reach UC Davis' top experts in drought and water management.
“Policymakers and the public need to see, not just be told, that UC Davis is a go-to place on drought,” said Jay Lund, director of the UC Davis Center for Watershed Sciences. “This site should help draw tighter the wide range of work done on drought and related subjects from all across the campus.”
Farmer and Rancher Voices from the Drought
Over the sound of bleating sheep and singing birds, Dan Macon describes how the current drought has affected his sheep ranch, Flying Mule Farm, in the Sierra Nevada foothills: “This is the driest of three dry years in a row for us … Over the last three years, we've reduced the size of our flock by half. Because we've reduced the size of our flock, I have taken a part-time job and will probably take a second part-time job this spring.”
His is one of several audio stories compiled as part of Farmer and Rancher Voices from the Drought.
A team of UC researchers began the project this spring. Led by Ken Tate, UC Davis professor of plant sciences and rangeland watershed specialist in Cooperative Extension, they use digital tools to capture the voices of farming and ranching families who are battling the worst drought of their careers.
Each week, the team posts new tracks to SoundCloud — an audio-streaming service and social network where users can upload, record and share tracks they create. Friends, loved ones and colleagues of ranchers and farmers are also invited to interview them and post tracks to the SoundCloud group page. Several of the farmers and ranchers share practices that have worked for them so that others struggling with the drought can better cope.
Members of the state's farming and ranching community also share stories, photos and comments at the project's Facebook group page.
The project was inspired by Caroline Henderson's “Letters from the Dust Bowl,” which documented the voices of farmers and ranchers leaving dust-covered Oklahoma in the 1930s in search of a better life in California.
Drought summit on April 25
Upcoming events: UC Drought Summit The Center for Watershed Sciences is organizing faculty from all UC campuses and other California universities to present a daylong Drought Science, Policy and Management Summit on April 25, 2014 in Assembly Committee Room 4202 at the state Capitol. Video recordings of presentations will be available soon after the summit at http://www.calchannel.com.Climate Change: Challenges to California's Agriculture and Natural Resources Monday, May 19, 2014 The California Museum 1020 O Street Sacramento, CA ------------------------------------------------------------------------------------------------------------------------
Past events: Labor, Water, and California Agriculture in 2014 Friday, April 18, 2014 UC Davis Law School Click for AIC Director Dan Sumner's slide presentation
------------------------------------------------------------------------------------------------------------------------Media articles:- UC Davis experts: Sources on California's drought
- California Seeing Brown Where Green Used to Be- California Farmers Brace for Drought, Unemployment - Calif. Rancher Still Optimistic Amid Record Drought - Californians brace for year of 'mega-drought' - California farmers brace for drought, unemployment - California Drought Impacts Produce Departments. - California Drought And The U.S. Food Supply ------------------------------------------------------------------------------------------------------------------------/h1>