Strip tillage and cover cropping for enhanced water use efficiency in western Washington organic vegetable farms

CSANR Project 159

Status: Complete

Project Summary

Tillage is an important tool in organic systems for weed control, residue management, seedbed preparation, and regulation of spring soil temperature. As excessive tillage wastes energy and degrades soil quality, organic producers are encouraged to reduce tillage. Soil water also evaporates more quickly from bare, tilled soils, potentially increasing irrigation demand. This integrated research and extension project compares the field water use efficiency of strip tillage and full tillage for organic winter squash production following a rye cover crop.

Annual Entries

2016

Principal Investigator: Doug Collins
Graduate Student: David Sullivan
Progress Report: http://csanr.wsu.edu/wp-content/uploads/2017/10/159CollinsSullivan.pdf
Grant Amount: $30,562

Publications

1. Poster, 2016 findings (SSSA and Tilth Alliance)
2. Peer reviewed extension video, “Reduced Tillage in organic vegetable production”, storyboard currently in review (WSU FastTrack)
3. April 25th 2016 Field Day Handout,
“Reduced Tillage Organic Agriculture Research” (https://www.dropbox.com/s/197mip10d0ybrne/HandoutApril2016ReducedTillFieldDay.pdf?dl=0)
4. August 1st 2016 Field Day Handout,
“Reduced Tillage Organic Agriculture & Irrigation Management” (https://www.dropbox.com/s/22xlqxctkgvc8hf/ReducedTillFieldDayHandout1Aug16.pdf?dl=0)

Additional Funds Leveraged

2016 Decagon Devices G.A. Harris Fellowship - $5,000 (awarded)
Annie’s Scholarship (awarded)

Impacts and Outcomes

• Short-Term: Two field days focused on reduced tillage in organic vegetable production were held at WSU Puyallup in 2016. Attendees were surveyed about their interest in reducing tillage, experiences in adopting reduced tillage practices, knowledge gained during the field days and intention to adopt practices that were discussed. There were a total of 101 attendees and 86 evaluations were received (85%). Forty-five percent of the attendees were farmers, and 30% of attendees were certified organic farmers.
Most respondents indicated that their primary interests in reduced tillage organic agriculture were improving soil quality (95%, n=82), reducing weed pressure (54%, n=46), and reducing greenhouse gas emissions (42%, n=36). Fewer attendees cited improved produce quality (36%, n=31) and reduced fuel usage (33%, n=28). 92% of Participants (n=35) of the second field day stated they had a somewhat to great increase in their knowledge of reduced-tillage equipment, cover crop nitrogen, soil moisture monitoring, long-term weed management, or transitioning to reduced-tillage systems. Most attendees (39%, n=35) identified themselves as being beginners (first season) or moderate (2 to 5 seasons; 34%, n=31) in reduced-till production while 24% (n=22) had greater than 5 years’ experience with reduced tillage. The most commonly cited barriers to adopting reduced tillage were lack of equipment and concerns around weed management.

• Intermediate-Term & Long-Term: Field day participants were asked about their future management plans in regards to reduced tillage and soil moisture management. Farmers that attended the second field day (n=12) indicated that they intended to make changes in long-term weed management (100%) and implement changes to transition to reduced tillage (75%). Additionally, 68% of all participants said they would change their soil moisture monitoring practices after the second field day (n=36).