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ARS Home » Pacific West Area » Pullman, Washington » Northwest Sustainable Agroecosystems Research » Research » Publications at this Location » Publication #324276
Title: Soil characteristics and wind erosion potential of wheat-oilseed-fallow cropping systems

Author
item Sharratt, Brenton
item SCHILLINGER, WILLIAM - Washington State University

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2016
Publication Date: 4/29/2016
Citation: Sharratt, B.S., Schillinger, W. 2016. Soil characteristics and wind erosion potential of wheat-oilseed-fallow cropping systems. Soil Science Society of America Journal. doi: 10.2136/sssaj2015.12.0427.

Interpretive Summary: Oilseed crops are vital to the future of biofuel production in the Pacific Northwest. However, wind erosion and atmospheric dust concentrations could escalate when growing oilseeds in conventional wheat-fallow rotations in the region. We found lower residue biomass and cover after sowing wheat in a wheat-oilseed-fallow rotation than a wheat-fallow rotation. As such, there is greater potential for wind erosion and dust emissions from the wheat-oilseed-fallow rotation. No other soil properties (i.e. water content, roughness, aggregation) were affected by growing oilseeds in a wheat-fallow rotation. Dryland wheat-fallow farmers and land managers in the Pacific Northwest must carefully manage crop residue using minimum-tillage or no-tillage practices to control wind erosion and improve air quality when growing oilseed crops.

Technical Abstract: Oilseeds are integral to the production of biofuels and diversifying rainfed cropping systems in the Pacific Northwest United States (PNW). However, there is evidence to suggest greater potential for wind erosion when growing oilseeds in wheat rotations. Little is known concerning the impact of growing oilseeds on soil surface characteristics that affect erosion. Soil characteristics were examined during the fallow phase of three crop rotations: (i) winter wheat - summer fallow (WW-SF), (ii) winter wheat - camelina - summer fallow (WW-C-SF), and (iii) winter wheat - safflower - summer fallow (WW-S-SF) at Lind and Ritzville, Washington. Crop residue biomass and soil water content, roughness, strength, and aggregate size distribution were measured immediately after sowing winter wheat. Camelina and safflower did not affect soil water content, random roughness, penetration resistance, geometric mean diameter, or the erodible fraction. Prostrate residue biomass and cover, however, tended to be greater in the WW-SF rotation. The Revised Wind Erosion Equation suggested that sediment transport could be from 55 to 210% greater for the WW-C-SF or WW-S-SF than the WW-SF rotation due to differences in crop residue characteristics after sowing wheat. These results indicate that crop residue must be carefully managed to minimize the occurrence and intensity of wind erosion from dryland oilseed cropping systems in the PNW. Specifically, no-tillage may be required to manage crop residue during the fallow phase of a wheat-oilseed-fallow rotation for controlling wind erosion.