- Author: Jeffrey P Mitchell
Information on the dynamics of long-term use of winter cover crops in California's San Joaquin Valley will be shared with online participants as part of the Desert Southwest Soil Health Webinar (https://www.eventbrite.com/e/desert-southwest-soil-health-webinar-tickets-107732693386), slated for July 23rd from 8 AM through 6 PM.
“This will be one of the first outlets in which we'll share our 20-year findings on both the costs and benefits of using cover crops to improve agroecosystem biodiversity and the efficiencies of the C, N, and water cycles in SJV annual cropping systems,” says UC ANR's Jeff Mitchell, whose presentation on conservation agriculture falls in the 10:30 AM – 3:00 PM “Practices to improve soil health,” slot on the day-long program.
Mitchell will describe how over the course of the project that was characterized by recurring drought, a total of 37 tons of aboveground cover crop biomass representing 1580 lbs N and 14.8 tons C per acre was produced with a total precipitation of 127 inches and 16 inches of supplemental irrigation in that was applied in four of the years. These inputs averaged 3,695 lbs of organic matter or 0.79 tons of C annually. Year-to-year variability was quite large ranging from 8,818 lbs OM in 2000 when supplemental irrigation was applied, to 54 lbs/ac in 2007 when, as in most years, no irrigation was applied to the cover crops. The cover crops were typically seeded by November 15 and terminated around March 15 of the following year accounting for a growth period of 120 days capturing solar energy by the “green ground cover”, and living roots in the soil for about 90 additional days during the year relative to the standard practice system which was bare during this time. Based on cover crop growth during years when supplemental irrigation was applied, Mitchell estimates that an average of 6,082 lbs of dry cover crop biomass might have been produced with a modest input of 2 inches of water. Even greater amounts of cover crop biomass – approximately 12,000 lbs of dry matter per acre as is typically achieved with winter silage triticale crops in SJV dairies - could be produced were cover crops “treated more like cash crops” with additional supplemental strategically timed irrigation in a cropping system as in other regions of the US. He'll also be showing participants via recorded video clips just how this sort of sustained cover crop use improves key soil health indicator properties and function.
CCA and PCA credit for the online webinar have been requested.
Photo caption
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UC ANR Cropping Systems Extension Specialist, Jeff Mitchell, shown sampling winter cover crop aboveground biomass in longstanding conservation agriculture study of the impacts of reduced disturbance, cover crops, and surface residues on soil function, productivity, and ecosystem services at the Conservation Agriculture Systems study site in Five Points, CA
New data on cover crops to be presented July 23rd!
- Author: Jeffrey P Mitchell
Fifteen years of stunning conservation agriculture success at Rollin Valley Farms in Burrel, CA!
June 22, 2020
Andy Rollin, along with his brother, Donny, are dairy farmers near the small western San Joaquin Valley town of Burrel, CA. Their farm, Rollin Valley Farms, milks over 2,000 cows and has about 700 acres of silage crops including alfalfa, corn, oats, wheat, and sudangrass. About 15 years ago, they began some of the earliest efforts to develop reduced disturbance production techniques for their silage crops (see video below). They pioneered the successful development of strip-till corn way back in 2003 and 2004 and then a few years later, began working with Monte Bottens and Cary Crum of California Ag Solutions (CAS) in Madera, CA, to further improve their production systems. Monte and Cary helped them with state-of-the-art planter improvements, an Orthman 1-tRipR strip-till implement and also the use of CAS's Landoll no-till grain drill. (See Picture 1). In addition, the Rollins have in recent years added a late-summer multi-species silage “cover crop” which has now augmented their annual forage production over their prior double-cropping practices. Strip-till corn yields at their farm are up about 2 to 3 tons/acre over prior production rates and there have also been 10 to 15% improvements in their feed quality that have resulted from the coupled, innovative efforts that they have made.
The Rollins were also involved with a research study back in 2004 and 2005 with CASI's Nick Madden, Randy Southard, and Jeff Mitchell to determine the impacts of their reduced disturbance practices on air quality. (See Picture 2.)This work showed that over 85% of dust emissions were reduced by strip-till compared to their previous standard till system (see the attached article by Madden et al. 2008). (See Picture 3).
The Rollins are now firmly behind their transition to strip-till and no-till cover crops and small grain seeding schemes and attribute an early spring savings of about 10 days to their reduced disturbance corn planting systems. They now have switched to watering up their strip-till corn following the very minimal soil work they do following winter small grain chopping and harvesting. In recognition of their innovative and steadfast progress, they were Finalists in the 2018 Leopold Conservation Award Program. The following short video shows one of their strip-till corn fields this spring. (See Picture 4.)
Here is a link to a You Tube video of this project: https://youtu.be/mq8itVs3Iak
- Author: Jeffrey P Mitchell
About 80 Master Gardeners of the UCCE group in El Dorado County came together to learn about the principles and practices of conservation agriculture in a lively discussion with CASI Workgroup Chair, Jeff Mitchell, on June 23rd at the group's monthly meeting in Placerville. The meeting was organized by Master Gardener event coordinator, Catherine Mone, and drew a very animated and engaged group of participants.
Mitchell talked about the core principles of conservation agriculture and the extent to which they're now being used around the world and recently in California. He showcased examples of pioneering innovation that have been achieved in a number of cropping contexts and also provided information and ideas as to why it will be increasingly likely that these sorts of production system options may have greater receptivity and resonance in California in the future. He ended his discussion with some examples of motivation that he has benefited from over the years from his professional mentor, Dwayne Beck of South Dakota State University. "Take the E out of ET and the T out of can't," was Beck's encouragement to Mitchell. This can be accomplished by protecting the soil surface with crop residues that cool soil temperatures and reduce soil water evaporation, and by not giving in to merely accepting the status quo, but by identifying bold, ambitious, and long-term cropping system goals and then coming up with the ways to achieve them. This is, according to Beck, "Nothing short of the agronomic and ecological equivalent of the space race back in the 1960's" and we are going to need to really dedicate tremendous creativity and effort toward achieving it.
CASI was very honored to be invited by the Master Gardeners of El Dorado County and we look forward to returning to Placerville in late September!
- Author: Jeannette E. Warnert
Mitchell, the chair of the UC Conservation Agriculture Systems Innovation Center, made the comment at the 6th World Congress on Conservation Agriculture in Winnipeg, Manitoba, last month.
After attending the congress, Mitchell said he is more strongly convinced that greater efficiencies and brighter economics in California agriculture could be achieved by employing conservation principles.
“Focusing on soil care will improve soil water intake and storage,” he said. “Reducing soil water evaporation can be achieved by preserving surface residues. Together these steps reduce energy use and greenhouse gas emissions – very important goals.”
The Manitoba congress drew more than 350 participants representing 47 countries. It was co-sponsored by the Conservation Agriculture Systems Alliance, the Conservation Technology Information Center, and the Canadian Soil and Water Conservation Society. California's CASI was represented by Mitchell and Monte Bottens, president of California Ag Solutions of Madera, a consulting and custom fertilizer support company.
Speakers at the conference suggested conservation agriculture principles are “transformative and not merely incremental means for achieving the kinds of change must be made to meet the global challenges of food production and natural resource conservation in the 21st Century,” Mitchell said. Modestly tweaking today's conventional agricultural systems, he said, “is not an option.”
Today conservation agriculture is used on about 11 percent of the world's total arable land. Implementation is increasing at an annual rate of about 7 to 8 million hectares, according to the U.N.'s Food and Agricultural Organization. Nearly half of the world's conservation agriculture acreage is found in the developing world. The South American countries of Brazil, Argentina and Paraguay, where the movement had its beginnings as a farmer-led process dating back to the mid-1970s, has about 80 percent implementation.
During his keynote address at the conference, David Montgomery, University of Washington professor of geology and author of Dirt: The Erosion of Civilizations, issued a “call to action.”
“Global soil degradation,” he said, “is an under-appreciated environmental crisis that occurs because of how we farm. We need to be more creative in terms of how we're intensifying agriculture to feed the post-oil world without cheap, fertilizer-intensive agriculture.”
Congress speaker Dwayne Beck, agronomy professor at South Dakota State University, also sounded an alarm.
“Never in history has mankind knowingly faced this type of impending catastrophe,” Beck said. “It is time to stop doing incremental things and start doing transformative things. You do not cross a chasm in two steps. We need to focus on where we want to be and emphasize systems, not details; actions, not reactions; and commitment, not merely involvement.”
CASI members are working with foundations and granting agencies to better position the organization to support implementation of conservation agriculture in California. For more information, contact Mitchell at (559) 303-9689.
- Author: Jeannette E. Warnert
Extensive research by UC scientists and innovative farmers has shown that making the changes can be challenging at first, but in time results in more efficient, environmentally sound and profitable food production systems.
“There’s a sense of inevitability now that these systems will be more widely adopted in California annual cropping systems,” said Jeff Mitchell, UC Cooperative Extension specialist in the Department of Plant Sciences at UC Davis.
| View a two-minute video snapshot of the field day and farm tour at the end of this post. |
The growing interest was demonstrated at a UC field day and farm tour in September in which more than 200 participants visited three farms already successfully implementing conservation practices and three sites at the field station where research on conservation farming practices is underway.
At Five Points Ranch, field day participants stood on an alfalfa field and inched along with an operating center pivot system. Farmer Armando Galvan has added “boom backs” behind the wheels that roll the system through the field. The boom backs make sure the wheel tracks stay dry until the wheels have passed, which prevents wheels from carving deep trenches in wet soil.
At the Morning Star dairy farm, John and JoAnne Tacherra irrigate rolling acres of forage with a center pivot irrigation system and have put the employees who used to undertake the punishing task of moving sprinkler sets to work inside the dairy barn. The center pivot system is controlled with the touch of a button. The combination of advanced nozzle packages and software that manages the pivot speed allow the Tacherras to distribute precise quantities of water and dispense the water with the ideal droplet size for each stage of the crop’s development. The couple now plans to experiment with the application of dairy lagoon water through the center pivot system.
At Farming “D” Ranch in Five Points, logistics manager Scott Schmidt experienced some problems with overhead irrigation this spring. Water was applied on cotton over triangular beds, slipped into the furrows and left seeds dry. Water infiltration was also inhibited when the wetted surface of the field dried into a crust and subsequent irrigation washed off. The crop had to be replanted.
“These sorts of problems can be solved,” Mitchell said. “Carefully designed nozzle packages and soil quality development practices will promote water infiltration.”
No-till farming and the use of cover crops have been shown at the UC West Side Research and Extension Center to enhance soil quality. When the tour returned to the center’s research plots, they viewed a 12-year study where plots have been maintained to compare the long-term effects of standard tillage techniques with no-till or minimum tillage systems, and both tillage methods combined with off-season cover crops.
The soil differences are dramatic.
Using clear canisters for a demonstration, Natural Resources Conservation Service soil conservationist Genett Carstensen poured a cup of water onto soil collected from a tilled plot and onto soil from a no-till plot managed with cover crops. The standard till soil repelled the liquid, which pooled at the top of the container; the no-till soil readily absorbed the water.
“This is what soil quality is,” Carstensen said.
She further demonstrated the soil quality differences by placing dirt clods from the two types of plots in canisters of water. The no-till clod maintained its composure; the clod from the tilled plot began dissolving immediately.
“The no-till clod has glued itself together with dead matter and dead microbes,” she said. “The standard till soil is going to erode and water is going to carry it off.”
At another research field, Steven Kaffka, UC Cooperative Extension specialist in the Department of Plant Sciences at UC Davis, is leading a study of what he calls “energy beets,” formerly known as sugar beets. The trial compares beet production under overhead irrigation and buried drip irrigation. Kaffka believes energy beets will be another competitive crop for California farmers because they can be used to produce ethanol, which will allow farmers to help the state reduce greenhouse gas emissions and achieve climate change goals.
The field day also included a glimpse of future research at the northeast corner of the West Side REC where industry donors have teamed up with UC to create a facility for state-of-the-art overhead irrigation study. Reinke Inc. donated a center pivot system, Senninger Irrigation donated nozzles, and Rain for Rent created an infrastructure that gets water and power to the research plot.
Replicated plots will be pie shaped and different treatments can be applied to each segment with the use of multiple sets of drop hoses. Studies will begin immediately to research deficit irrigation of alfalfa, corn, sorghum and cotton.
“Because of the water situation in California, deficit irrigation is going to be something we will need to know a whole lot more about, for better or for worse,” said Bob Hutmacher, UC Cooperative Extension specialist in the Department of Plant Sciecnes at UC Davis and director of the West Side Research and Extension Center.
View a two-minute video snapshot of the field day and farm tour:
