Conservation Agriculture Systems Innovation
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Conservation Agriculture Systems Innovation

Conservation agriculture news

CASI Farmers Host New UC Davis Agroecologist, Amelie Gaudin

Amelie Gaudin discussing ecological practices with farmers.

CASI farmer members, Michael and Adam Crowell of Turlock, Darrell Cordova of Denair, and Scott Schmidt of Five Points, along with Jeff Mitchell, hosted Amelie Gaudin, the new professor of Agroecology in the Department of Plant Sciences at UC Davis at their farms on January 23, 2015 to share with her information about their farms and the efforts they have made to improve their crop production systems. Each of these farmers very graciously welcomed Dr. Gaudin who has been on the job in Davis for only three weeks.

Dr. Amelie Gaudin has tremendous experience with cropping system ecology and is currently establishing her research lab in Davis that is focusing on using agroecological principles to help develop efficient and resilient cropping systems. Three current themes that she will be emphasizing in her research program of her lab group are ecological intensification, climate-smart agroecosystems, and evolutionary root ecology, - all very nicely related to the core goals of our CASI Workgroup.

Additional information about Dr. Gaudin's work is available at her website and via email at


Posted on Monday, January 26, 2015 at 9:52 AM

Grant funds new high school ag sustainability courses

Jeff Mitchell receives $5,000 grant from Monsanto.
Plant Sciences' Jeff Mitchell received a $5,000 grant recently from the agricultural biotechnology company Monsanto to support a program of high school activities aimed at sustainability.

Mitchell, a UC Cooperative Extension cropping systems specialist, will work with through the Conservation Agriculture Systems Innovation (CASI) Center, which promotes the principles of conservation agriculture: reduced disturbance, diversity and year-round soil health improvement practices. The internationally recognized sustainability method is now making inroads to California, particularly as a low-input high-retention approach to dealing with drought conditions.

CASI has established a network throughout California's Central Valley of high school teachers committed to the upcoming pilot program. Farm training sessions will extend the classroom learning the students currently gain in their coursework, with CASI experts sharing their knowledge and excitement for agriculture and agricultural science.

“In my own class that I am teaching this fall at UC Davis, the students themselves have selected as the topic for their panel discussion ‘California's new farmers,'” says Mitchell, “which is, I think, a fitting testament to the sheer importance of young people and the need to educate and inspire this next generation of folks who'll be responsible for agricultural production systems in the future.”

Posted on Monday, December 1, 2014 at 10:24 AM
  • Author: G. Bradley Hooker

2014 Conservation Tillage Farmer Innovator Award goes to Darrell and Trevor Cordova

Darrell and Trevor Cordova at the November 24 field day.
The University of California Conservation Agriculture Systems Innovation Center (CASI) has named Darrell and Trevor Cordova of Denair recipients of the 2014 Conservation Tillage Farmer Innovator Award.

Jeff Mitchell, UC Cooperative Extension specialist and CASI chair, presented the award to the father-son team at a field day on their Denair farm Nov. 24.

“Darrell and his son Trevor are tenacious, committed and skilled farmers,” Mitchell said. “They have demonstrated innovation and leadership in development, refinement and use of conservation tillage systems that more than meet the criteria for this award.”

In July 2003, the Cordovas summoned a group of UC Cooperative Extension researchers to their farm, including Ron Vargas, emeritus agronomy and weed advisor in Madera and Merced counties; Anil Shrestha, then UC Integrated Pest Management weed ecologist; and Mitchell. They were farming an usual mixture of crops – including corn, wheat, triticale and other winter forage species, along with almonds – on a farm with rolling hills on the eastern edge of the San Joaquin Valley floor.

“They wanted to begin a dialogue about their interest in trying conservation tillage in an edible dry bean-wheat rotation,” Mitchell said. “Darrell and Trevor were inquisitive and eager to make reduced tillage work at their farm. They jumped into these early investigations with both feet.”

Darrell Cordova also consulted with Ralph Sesena, Sr., president of Cesena Distributing of Stockton, Calif., and recipient of CASI's 2013 Privater Sector Innovator Award. Sesena suggested the Cordovas try no-till bean seeding using a Buffalo slot seeder. He worked with them as they successfully planted no-till winter small grains following their summer beans.

During the early years, weed management was a serious challenge. Because of weed pressure in their beans and wheat, they developed a minimum-tillage approach that involved a shallow disking operation before crop changes.

Things changed again in 2007. The Cordovas invested in a 165-acre corner arm center pivot irrigation system and a dairy farm was established adjacent to their property, prompting them to grow dairy silage.

“With this new rotation scheme, Darrell and Trevor once again became interested in no-till production,” Mitchell said. “They developed no-till capabilities for both their summer silage corn and their winter forage mixes.”

When they saw their corn grow taller and greener under the new no-till management, the duo purchased a new eight-row planter and a 20-food no-till drill in 2014.

“Darrell and Trevor have made major strides in their ability to use conservation tillage practices at their farm and are now truly two of CASI's most outspoken champions for these innovative conservation agriculture systems,” Mitchell said. “They continue to serve as important advisors to our ongoing conservation agriculture and center pivot irrigation work.”

Following the award ceremony for the Cordovas, Dennis Chessman, state agronomist with the USDA NRCS; Margaret Smither-Kopperl, director of the NRCS Plant Materials Center; and Mitchell led a discussion and demonstration of some of the improvements in soil health that have been seen in fields where reduced disturbance techniques are used and where residues are maintained.

Mitchell noted the importance of these conservation agriculture practices that the Cordovas are using for increasing the water use efficiency of cropping systems by reducing soil evaporation and cooling surface soil temperatures. He told the gathered field day participants that longterm work in Five Points, Calif., has demonstrated that soil water evaporation losses can be reduced by as much as five inches during a routine summer crop season using these practices.

At the field day honoring the Cordovas for their progress with conservation agriculture practices coupled with precision overhead pivot irrigation, Mitchell said the team has implemented “quite significant strategies for producing more with less.”

“Not only have Darrell and Trevor Cordova been successful at significantly cutting their overall production costs, but they've also increased the water use efficiency of their production systems," Mitchell said.

Posted on Monday, December 1, 2014 at 9:40 AM

Tillage practices continue to change

California's Conservation Agriculture Systems Innovation (CASI) Center, in partnership with Sustainable Conservation and the USDA Natural Resources Conservation Service, has prepared its survey of tillage management acreage for 2012. This tillage survey was conducted as an ongoing comparison of annual row crop acreage that is farmed under different tillage systems throughout the Central Valley region of California. Over 35 local NRCS, University of California and private sector experts were surveyed and results were compared with 2012 County Agricultural Commissioner cropland acreage reports. Previous surveys have been conducted in 2004, 2006, 2008 and 2010.

Data in this survey were compiled for two general types of reduced tillage systems. Tillage practices such as no-till, strip-till, ridge-till and mulch-till, that leave at least 30% of the residue from previous crops in place on the soil surface are the typical forms of conservation tillage that are recognized throughout the world and that have historically been chronicled as one category of reduced tillage in our survey. In addition to these practices, “minimum tillage” practices that reduce the overall number of tillage passes by at least 40% relative to what was done in the year 2000, are also included in the tally of conservation tillage acreage.

A number of complicating factors, including changes in cropping acreage and rotational crop selections that were being implemented in 2012 as California's drought began to take hold and changes and turnover in the local expert reporters who have provided input for the survey estimates over the years, may be apparent in the 2012 survey results. These methodological challenges notwithstanding, the 2012 survey has been carefully checked and represents a useful view to the ‘big picture' trends that may be occurring in the region and that may warrant more detailed investigations to determine why certain patterns are being noted.

In 2012, conservation tillage systems accounted for about 17% of the total acreage for the crops that were surveyed including silage and grain corn, small grains for hay, silage and grain, tomatoes, cotton, dry beans, and melons throughout the nine-county Central Valley region. This was an increase from about 14% in 2010. Minimum tillage practices were used on about 15% of crop acreage in 2012, a reduction from about 24% in 2010.

The largest change in conservation tillage acreage from 2004 – 2012 is found in the amount of corn silage acreage that uses strip-tillage. In 2004, there were only about 490 acres of summer silage corn using strip-till, while in 2012 over 181,000 acres throughout the San Joaquin Valley region had adopted the use of this form of conservation tillage. Another major trend during this time has occurred with minimum tillage tomato acreage increasing from about 3% in 2004, to about 58% in both 2010 and 2012. Speculation as to why minimum tillage acreage overall tended to decline from 2010 to 2012 may relate to issues with herbicide application practices as well as soil salinity patterns that occur particularly with subsurface drip irrigation that have become concerns for farmers if broadcast, full-area tillage is not performed. A full and detailed report of CASI's tillage acreage survey is available at our website:

 Table 1.

California conservation tillage acreage survey (2012) for tomatoes, cotton, edible dry beans, silage corn, grain corn, and small grains for grain, hay and silage, CT – conservation tillage, MT – minimum tillage, September 14, 2014


>30% residue cover after planting

>40% reduction in total passes

<30% residue cover after planting

Total Acreage

CT as a % of Total Acreage

CT and MT as a % of Total Acreage


Conservation Tillage Total

Minimum Tillage Total

Conventional Tillage



































































San Joaquin





































Table 2.
Changes in the percentage of acres of conservation tillage (CT) and minimum tillage (MT) relative to the total number of acres for 2010 and 2012 for all surveyed crops, and for tomato, cotton, and silage corn individually.


Total Acreage

Tomato Acreage

Cotton Acreage

Silage Corn




































































For additional information and of various forms of conservation tillage, please contact Jeff Mitchell at (559) 303-9689 or  For information on the equipment rental program for strip-tillage and silage corn planting, contact Ladi Asgill (209) 604-6554 or

Posted on Thursday, October 2, 2014 at 3:01 PM

Farmers cutting costs by cutting tillage

Recent investigations conducted by UC's Conservation Agriculture Systems Innovation (CASI) Center shed light on opportunities farmers have for cutting production costs in their cropping systems by reducing tillage. Founded in 1998, CASI is a large group of diverse members including UC researchers, farmers, private sector, NRCS and other public agency partners who work together to develop and spread information about production systems alternatives that aim to increase profitability and efficiencies, conserve resources and be readily adaptable to local marketing and environmental conditions.

Citing a number of studies the group has published over the past several years at a recent workgroup meeting in Five Points, Calif., CASI workgroup chair, Jeff Mitchell, summarized the potential savings that can be gained by a variety of reduced tillage approaches as being typically between $50 and $140 per acre per season depending on the particular crop and set of practices or equipment that are used.

“For a number of crops including tomato, cotton, silage corn, sorghum, and sugar beets, that we've run the numbers for, this seems to be the range of savings that can be achieved by using various minimum tillage implements that combine customary tillage operations into fewer passes, or more classic forms of conservation tillage such as strip-tillage or no-tillage," Mitchell said.

CASI Workgroup tomato farmers, Alan Sano, Jesse Sanchez and Steve Fortner of Firebaugh have all seen this range of cost reductions since moving to minimum tillage practices that they couple with subsurface drip irrigation and cover crops when water is available to improve their soil's tilth, water movement and storage.

“Our yields are actually higher now with about four inches less water than when we were furrow irrigating and using conventional tillage,” reports Jesse Sanchez in a recent survey that is available at the CASI website

Tom Barcellos, a Tipton, Calif., dairy farmer and President of Western United Dairymen, calculates savings of about $70 per acre that he has accomplished with strip-till and no-till silage corn over his former conventional intercrop tillage practices. There are also savings in time as well as wear and tear on equipment that he has achieved since transitioning to these conservation tillage practices in 2003.

Alan Wilcox, another CASI workgroup founding member and minimum tillage equipment entrepreneur in Walnut Grove, Calif. has created a tillage cost calculator tool that he uses to determine savings that may result from reduced pass practices.

“Knowing the true costs of tillage is essential,” Wilcox says, “since tillage is one of the few things in their overall budgets that farmers can control.”

Posted on Wednesday, October 1, 2014 at 3:01 PM

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