News Releases

June 4, 2004

Conservation tillage comparison emerges from 16-year study of sustainable farming practices

Soil sampling at UC Davis conservation tillage and cover cropping research site.

DAVIS -- A new location and purpose for a successful 16-year-old farming comparison project at UC Davis will be revealed at a field day June 24. The study of alternative practices, which has helped change the way Sacramento Valley farmers grow field crops, has evolved into a farming systems experiment focused on conservation tillage.

Charles "Chuck" Ahlem, the undersecretary of agriculture for the California Department of Food and Agriculture, will be the field day keynote speaker. State Secretary of Agriculture A.G. Kawamura is an invited guest at the event, which will take place at UC Davis' Russell Ranch, seven miles west of the main campus.

The project's new permanent site is also home to the UCD College of Agricultural and Environmental Sciences' Long-Term Research in Agricultural Systems experiment.

"Both experiments are part of the college's emerging sustainable agriculture and natural resource program," said William Horwath, the project leader and UC Davis professor of land, air and water resources.

"We're emphasizing conservation or reduced tillage, and the use of non-cash cover crops to improve soil and water quality in typical California cropping systems," said Horwath. More than 20 faculty, Cooperative Extension researchers and growers are participating in experiments at the site. Participants are working with UC's statewide Sustainable Agriculture Research and Education Program (SAREP) on outreach.

Some of the most important results from the original Sustainable Agriculture Farming Systems project showed where growers can reduce synthetic fertilizer inputs; how to manage cover crops, crop residue and soil organic matter; and how to manage weeds and pests with fewer pesticides, Horwath said. The project, which began in 1988 with funding from SAREP, developed a much clearer understanding of the economic opportunities and limitations of organic farming practices.

"The new project has a different focus," Horwath said. "Now we're studying the effects of conservation tillage and cover cropping on the way sediment, nutrients and pesticides are transported off conventional, cover-cropped and organic farming systems."

"We're also looking at the tradeoff between ecological benefits and economic costs in a sustainable system," he said. "And, it is vital that we share our results with farmers and the broader agricultural community."

Horwath said the project continues to rely on input from the growers and farm advisors on the research team. The geographic scope of the project has expanded, with researchers taking measurements at farms in Yolo and Stanislaus counties to identify relationships between management practices and runoff in different areas. A CALFED grant is funding a major portion of the work, with additional support from the California Department of Food and Agriculture and Unilever Bestfoods.

In addition to the main plots at the Russell Ranch, the project includes a 14-acre area for companion studies designed to refine management practices for successful use of conservation tillage and cover cropping in Yolo County conditions.

The SAFS field day gets underway with a 7:30 a.m. sign-in. Undersecretary Ahlem's keynote begins at 8 a.m. Participants will board tractor-drawn hay wagons to tour the research site at 8:30 a.m. At four sites, researchers will discuss water management and conservation in cover crop-based cropping systems; conservation tillage in tomato and corn production; weeds in furrow, drip and sprinkler irrigation system comparisons; and soil fertility and plant nutrition. After lunch, participants will hear updated information on the economic impact of conservation tillage. The final event of the day is a grower panel discussion, which has become a favorite for growers, pest control advisers and certified crop advisers interested in farmers' perspectives on the research results presented. The field day is scheduled to adjourn at 2:30 p.m.

Pre-registration is requested by June 18. The $10 fee ($5 for students) will cover the cost of lunch and refreshments. PCA and CCA Continuing Education units are pending.

Registration and directions are on the Web at . The site is located seven miles west of the main UC Davis campus on Russell Blvd., 1/2 mile west of County Road 95. For more information, contact Sam Prentice at (530) 752-2023 or