|STROM, L - Washington State University|
|PRESSLEY, SHELLEY - Washington State University|
Submitted to: Aeolian Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/17/2015
Publication Date: 9/20/2015
Publication URL: http://www.sciencedirect.com/science/article/pii/S1875963715000567
Citation: Sharratt, B.S., Graves, L., Pressley, S. 2015. Nitrogen loss from windblown agricultural soils in the Columbia Plateau. Aeolian Research. 18:47-53.
Interpretive Summary: Nitrogen is a valuable resource in crop production, but losses can occur by leaching and runoff. Comparatively little is known about N losses associated with wind erosion, which is a major concern in the Inland Pacific Northwest. Sediment eroded by wind contained about 0.09% N. Nitrogen loss during single wind erosion events was as high as 1.9 kg N ha-1; this loss constitutes about 4% of the nitrogen applied as fertilizer. Dryland wheat growers must be judicious in managing their crop land to minimize wind erosion and thereby conserve both the soil and N resource.
Technical Abstract: Wind erosion of agricultural soils can degrade both air quality and soil productivity in the Columbia Plateau of the Pacific Northwest United States. Soils in the region contain fine particles that, when suspended, are highly susceptible to long range transport in the atmosphere. Nitrogen (N) associated with off-site transport of windblown particulate matter depletes the parent soil of a valuable resource important in sustaining the biological activity of soils. The objective of this study was to quantify the loss of N in soil eroded from agricultural fields during high wind events. Soil eroded from the fields subject to conventional tillage in winter wheat-summer fallow rotations in eastern Washington was trapped in creep and Big Spring Number Eight (BSNE) samplers installed on the leeward side of fields at heights of 0 to 1.5 m above the surface. The location of field sites varied over the eight years of this study, but all sites were characterized by soils with a silt loam texture and annual precipitation of =305 mm. Nitrogen content of the parent soil ranged from 0.063 to 0.090% while N content of sediment trapped by the samplers during high winds ranged from 0.053 to 0.101%. Enrichment ratios (ER) for N ranged from 0.8 to 1.3, indicating the sediment was not highly enriched in N as compared with the parent soil. Nitrogen loss was estimated to range from 0.1 to 1.9 kg ha-1 during a high wind event. Nitrogen loss may be reduced by using conservation practices that have been proven effective in controlling wind erosion.