2012 Dryland Field Day Abstracts - Dept. of Crop and Soil Sciences ...

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the -3°C freeze, and (4) as in treatment (2) but with the freeze-thaw cycle repeated
twice. Plants that had been exposed to one freeze-thaw cycle survived significantly
more frequently than plants frozen without a freeze-thaw pre-freezing treatment
(Fig. 1). Thawing for 48 hours did not improve survival compared to thawing for 24
hours (Fig. 1). Subjecting the plants to two cycles of freezing and thawing (for 24
hours) resulted in greater survival than one cycle (Fig. 1). These results indicated
that cold-acclimated wheat plants actively acclimate to freezing stress while
exposed to mild subfreezing temperatures, and further acclimate when allowed to
thaw at +4° C for 24 hours. Because thawing for 48 hours did not improve survival
compared to thawing for 24 hours, it appeared the processes involved in this freeze
-thaw enhanced freezing tolerance were essentially complete within 24 hours of
returning to above-freezing temperatures. However, because two freeze-thaw
cycles resulted in greater survival than one cycle, it appears the process can be
restarted, or a second process started, by again returning to subfreezing
temperatures after an initial freeze-thaw cycle. Further study of the response to
freeze-thaw cycles may result in the discovery of previously unknown genes that
contribute to the ability of wheat plants to survive the winter.
2012 Field Day Abstracts: Highlights of Research Progress
Fig. 1. Average survival of 22 winter wheat
cultivars after 0, 1, or 2 freeze-thaw cycles
with freezing at -3°C,followed by thawing at
+4°C for 24 or 48 hours. Bars with the same
letter indicate nonsignificant differences.
Final Agronomic and Economic Results from the WAWG/NRCS Undercutter Project
Doug Young, School of Economic Sciences, WSU; Bill Schillinger, Dept. of Crop and Soil Sciences, WSU; Harry Schafer,
manager, WAWG/NRCS Undercutter project
The Washington Association of Wheat Growers/Natural Resources Conservation Service (WAWG/NRCS) Undercutter Project was
targeted to the winter-wheat/summer fallow region of Washington and Oregon that receives 12 or less inches average annual
precipitation. The undercutter method of summer fallow employs wide-blade V-sweeps for primary tillage plus fertilizer injection,
followed by as few as one non-inversion rodweeding operation. The undercutter method increases surface residue and roughness
that provides significantly more protective cover against wind erosion compared to traditional conventional tillage.
Forty-seven growers located in 10 counties in Washington and Oregon enrolled in the program. Participating growers received a 50
percent cost share for purchase of a new undercutter capable of injecting fertilizer on the condition that they use their undercutter
for primary spring tillage plus fertilizer injection on at least 160 acres per year for three years. These growers were interviewed
regarding the agronomic and economic performance of undercutter versus conventional fallow twice per year during 2008-2010.
Interview results showed that participating farmers achieved statistically equal winter wheat grain yields on the same farms within
years for the two systems which implied equal economic gross returns. Similarly, statistically equal glyphosate, fertilizer, seed, and
other input use implied equal costs for these inputs. Furthermore, there were no significant cost differences between systems in
fertilizer application or primary spring tillage. Consequently, economic budgeting shows that the undercutter and conventional
tillage systems averaged equal profitability. These results obtained from actual farms over three years confirm data of equal
profitability based on an earlier 6-year field experiment conducted at Lind, WA that compared undercutter and conventional tillage
systems. Surveyed farmers’ subjective satisfaction with the undercutter also improved over time. Furthermore, in all years, 40% or
more of farmers expected greater profit with the undercutter.
On the other hand, farmers reported a “learning curve” with the undercutter and variable performance on different soils.
Participants complained most frequently about maintaining depth control at speeds greater than 4 miles/hr, blade wear, difficulty
operating in heavy residue, shank kickbacks not setting properly, and problems with large soil clods leaving some air voids between
the surface and the depth of tillage. Blade wear can be reduced by at least 50% by chrome plating which also permits soil to more
easily slide over the undercutter blade, thus reducing drag. Large clods can be readily sized, and air voids eliminated, with a light
weight rotary harrow-type implement that attaches directly to the back of the undercutter frame. Many of the farmer participants
installed such an attachment on their undercutter.
This study provides promising economic results for the environmentally-friendly undercutter tillage fallow system. With the
demonstration of equal profitability through paired comparisons of undercutter and conventional systems within the same farms
and years during this 3-year study, we conclude the undercutter system offers a costless air quality gain to society and soil
conservation benefit for farmers. This study provides a rare multi-year on-farm statistical confirmation of a promising conservation
tillage method.