Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2013
Publication Date: 3/20/2014
Citation: Sharratt, B.S., Schillinger, W. 2014. Windblown dust potential from oilseed cropping systems in the Pacific Northwest United States. Agronomy Journal. 106:1147-1152. Interpretive Summary: The United States has established a goal of producing 36 billion gallons of biofuel by 2022. This demand will in part be met by growing oilseed feedstock. Little is known about the impact of growing oilseed crops on wind erosion in the Inland Pacific Northwest United States where poor air quality is a major environmental concern. We found that emission of windblown dust (including PM10 or particles less than 10 microns in diameter regulated by the US EPA) was as much as 250% higher from oilseed crop rotations than conventional wheat rotations. To maintain good air quality, farmers must be vigilant in protecting the soil from wind erosion when growing oilseeds on western agricultural drylands.
Technical Abstract: The volatility of petroleum reserves and prices coupled with concerns over greenhouse gas emissions and climate change has created a worldwide interest in renewable fuels. Although advances are being made in growing oilseeds for advanced biofuels, little is known about the impact of growing oilseed crops on natural resources. The objective of this study was to examine the impact of growing oilseeds in conventional wheat-fallow rotations on wind erosion and PM10 (particles less than or equal to 10µm in diameter) emissions in Washington where atmospheric PM10 is an acute environmental concern. Wind erosion and PM10 emissions were measured after sowing winter wheat in a winter wheat-summer fallow (WW-SF) rotation, winter wheat-camelina-summer fallow (WW-C-SF) rotation, and winter wheat-safflower-summer fallow (WW-S-SF) rotation. During the 13-month fallow phase of the rotation, the soil was undercut and fertilized in spring and rodweeded prior to sowing winter wheat. A wind tunnel was used to assess horizontal sediment and PM10 flux after sowing wheat; this being the time when the soil is most susceptible to wind erosion. Sediment and PM10 flux were as much as 250% higher after sowing winter wheat in the WW-C-SF and WW-S-SF rotations compared with the WW-SF rotation. Our results suggest that wind erosion and PM10 emissions are accentuated after sowing winter wheat in WW-C-SF and WW-S-SF rotations as compared with the traditional WW-SF rotation. Therefore, land managers must be judicious in protecting the soil from wind erosion during the fallow phase of the rotation in WW-C-SF and WW-S-SF rotations.