Triple-cropping Dairy Forage Production Systems Through Conservation Tillage in California's San Joaquin Valley

Triple-cropping Dairy Forage Production Systems Through Conservation Tillage in California's San Joaquin Valley

Summary

We have nearly completed this study at a number of dairy silage production fields in California’s San Joaquin Valley (SJV). This Western SARE-funded project was initiated in 2008 to evaluate potential benefits of conservation tillage-enabled (CT) triple cropping as a means for producing more silage, and thereby removing more manure nitrogen from dairy corrals. Side-by-side comparisons of standard tillage double cropping versus conservation tillage triple cropping are ongoing. Silage growth and nitrogen accumulation have been sampled, and soil nitrogen has also been determined at key times during each crop. Silage yields have also been determined for each crop. Data are now being compiled to calibrate a manure N management model that will help guide efficient applications. We have held several public field days related to this project and have also conducted a broad survey of soil surface residue accumulation under conservation tillage in silage fields. Finally, we are now also in the final stages of compiling data from a survey of tillage practices in the SJV and an additional survey that identifies barriers and constraints for the adoption of CT in California.

Objectives/Performance Targets

1) To determine the growth and productivity of year-round silage production of winter small grains, such as wheat and triticale, strip-till corn and late-summer sorghum sudan in a triple crop rotation in California’s San Joaquin Valley,

2) To increase the reliability of triple cropping dairy forage production with the use of CT practices as a means of increasing forage biomass and nutrient uptake by determining production rates and N removal in triple cropped forage fields compared to standard double cropped fields,

3) To evaluate triple cropping compared to standard double cropping forage production in terms of whole dairy nitrogen budgets and profitability,

4) To extend widely information developed by the project to dairy farmers, consultants and industry groups via a variety of extension education means,

5) To conduct a survey of farmer perceptions of benefits and barriers to the adoption of CT in silage production systems, and

6) To track changes in the adoption of CT forage production practices in the SJV as evidenced by CT acreage surveys conducted by California’s CT Workgroup and CT equipment sales records.

Accomplishments/Milestones

During the current reporting period, we have continued implementation of this study and have worked to complete each of the objectives we set for ourselves. Progress has been made with respect to silage sampling, growth and development and final yield determinations for each silage crop produced at the farms we have been partnering with. These field evaluations have consisted of triple cropping (the production of three forage crops in a given year) vs standard double cropping practices, and we have evaluated these systems at two primary dairy silage field sites. One site has been in Turlock, CA and the other has been in Modesto, CA. At each site, we have sampled silage biomass production and tissue nitrogen content for each of the crops in these dairy silage fields at about weekly intervals through the course of the study. Soil nitrogen has also been monitored at key times during each crop cycle, and soil and air temperature information has also been collected. Data from these monitoring activities are now being compiled and summarized and will be finalized by the time we submit our final report by the end of this year. In addition, large-scale field yield determinations have been made in conjunction with each partner farmer. We are also hopeful to use these data to parameterize the APTRAC Manure N Management Model. An adjunct evaluation of twin-row strip-tilled corn vs single-row strip-tilled corn was also initiated at a dairy in Hanford, CA and percentage residue cover has been determined for three other dairy silage fields during the project period. We have also held three extension education events associated with this study during the current period.

In our 2009 annual report, we identified and addressed two constraints of CT that have been observed at the two primary study sites that we have been tracking. These were manganese deficiency that occurred in one year at one site in the strip-till section of the study field, and difficulties in establishing an adequate corn stand using strip-tillage that occurred at the other farm site. We have since attempted to remedy this situation by having better consistency and closer tracking of the strip-tilled disturbed areas by using the same GPS system on the tractor. A relatively positive outcome from the most recent cycle of the work was the observation by one cooperating farmer that he had improved his winter small grain silage production due, he thought, to an improved variety, better herbicide selection and a better stand.

Impacts and Contributions/Outcomes

I regret not being ready or able to provide our final summary of findings from this work. This will be forthcoming later this fall.

Outreach:

June 28, 2010. Diary silage conservation tillage farm tour to Bar-Vee Dairy, Turlock, CA and Correia Family Dairy, Santa Nella, CA. 15 participants.

June 29, 2010. Dairy silage conservation tillage farm tour to Giacomazzi Dairy, Hanford, CA and Barcellos Farms, Tipton, CA. 30 participants.

July 12, 2010. Conservation tillage silage production expanding in California’s San Joaquin Valley. Web publication for Progressive Forage.

February 11, 2010. Conservation tillage and cropping systems Workgroup. M52 Information Site. 2010 World Ag Expo. 300 participants. Tulare, CA.

August 13, 2010. “Aussie no-till farmers visit SJV farmers.” Produced press release article distributed to over 250 outlets and posted at the Conservation Tillage and Cropping Systems Workgroup’s website.

We have received over 400 completed surveys of barriers to adoption of conservation tillage. These are being analyzed this fall.

Also, our 2010 conservation tillage acreage survey is almost completed.

• San Joaquin Valley Dairy Farmer Project Partner Sharing Information at World Ag Expo in Tulare, CA
• San Joaquin Valley dairy farmer WRSARE Project partner sharing information about his conservation tillage silage production practices, Turlock, CA
• San Joaquin Valley dairy farmer WRSARE Project partner sharing information about his conservation tillage silage production practices, Santa Nella, CA
• Hanford, CA dairy silage farmer sharing information about strip-till corn at public field day

Collaborators: