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ARS Home » Pacific West Area » Pendleton, Oregon » Columbia Plateau Conservation Research Center » Research » Publications at this Location » Publication #250557
Title: Comparison of Fallow Tillage Methods in the Intermediate Rainfall Inland Pacific Northwest Environments

Author
item RIAR, DILPREET - Washington State University
item BALL, DANIEL - Oregon State University
item YENISH, JOSEPH - Washington State University
item Wuest, Stewart
item CORP, MARY - Oregon State University

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/7/2010
Publication Date: 10/7/2010
Citation: Riar, D.S., Ball, D.A., Yenish, J.P., Wuest, S.B., Corp, M.K. 2010. Comparison of Fallow Tillage Methods in the Intermediate Rainfall Inland Pacific Northwest Environments. Agronomy Journal. 102:1664-1673.

Interpretive Summary: A study was conducted near Davenport, WA and Helix, OR over two fallow-winter wheat cycles to evaluate the efficacy of reduced tillage systems compared to conventional tillage for weed control, soil moisture, crop residue, and winter wheat yield and quality. Another objective was to evaluate light-activated sensor-controlled herbicide application. The sensor-controlled sprayer provided similar weed control as standard broadcast sprayer in no-tillage systems with less herbicide use. No-tillage and sweep undercutter treatments retained 7 to 38% more surface crop residue compared to the conventional tillage system. At planting time, the average soil moisture content of reduced tillage systems was similar to conventional tillage across locations. Seed-zone moisture conditions at Helix, a lower precipitation location, necessitated the use of a deep-furrow type drill in all tillage systems to place seed in moisture zone. This drill type was inappropriate for no-till seeding, and affected the time of planting, wheat emergence, and subsequent yield in no-tillage systems. The conventional tillage system had similar wheat grain yield and quality as the undercutter system, but yielded 10 to 21 percentage points more compared to no-tillage systems across years and locations.

Technical Abstract: A study was conducted near Davenport, WA and Helix, OR over two fallow-winter wheat cycles (2007-2008 and 2008-2009) to evaluate the efficacy of reduced tillage systems compared to conventional tillage for weed control, soil moisture, crop residue, and winter wheat yield and quality. Another objective was to evaluate light-activated sensor-controlled (LASC) herbicide application technology for weed control efficacy and herbicide use in fallow. Treatments included conventional tillage (CTRW), undercutter sweep tillage followed by (fb) rodweeder (STRW), broadcast sprayer (STB) or LASC sprayer (STL), and no-tillage fb broadcast sprayer (NTB) or LASC sprayer (NTL). The LASC sprayer provided similar weed control as the broadcast sprayer in no-tillage systems with 45 to 70% less herbicide use. All no-tillage and sweep undercutter fb herbicide treatments retained 7 to 38% more surface crop residue compared to the conventional tillage system. Following summer fallow treatments but prior to planting wheat, the average soil moisture content in 150 cm and seed-zone soil profiles of reduced tillage systems was similar to conventional tillage across locations. Seed-zone moisture conditions at Helix, a lower precipitation location, necessitated the use of a deep-furrow type drill in all tillage systems to place seed in moisture zone. This drill type was inappropriate for no-till seeding, and affected the time of planting, wheat emergence, and subsequent yield in no-tillage systems. The conventional tillage system had similar wheat grain yield and quality as STRW and STB but yielded 10 to 21 percentage points more compared to STL and no-tillage systems across years and locations.