Early-season wind erosion influenced by soil-incorporated green manure in the Pacific Northwest

Authors: Sharratt, Brenton; MCGUIRE, ANDREW - Washington State University; HORNECK, DONALD - Oregon State University

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/14/2018
Publication Date: 5/10/2018
Citation: Sharratt, B.S., McGuire, A., Horneck, D. 2018. Early-season wind erosion influenced by soil-incorporated green manure in the Pacific Northwest. Soil Science Society of America Journal. 82:678–684. https://doi:10.2136/sssaj2018.01.0018.
DOI: https://doi.org/10.2136/sssaj2018.01.0018

Interpretive Summary: Irrigated agricultural lands in the Inland Pacific Northwest are very susceptible to wind erosion, particularly when crops are sown in spring. While alternative management practices are sought that will reduce wind erosion, vegetable growers claim that incorporation of a cover crop as a green manure into the soil prior to establishing potato reduces wind erosion in spring. We found no difference in wind erosion potential between soils treated with or without a green manure at two locations in the Inland Pacific Northwest. Other management strategies such as minimum or reduced tillage may aid growers in promoting aggregation and/or enhancing residue cover and thereby reducing wind erosion of irrigated soils in the region.

Technical Abstract: Management strategies are sought to minimize wind erosion of irrigated agricultural soils along the Columbia River of the Inland Pacific Northwest, particularly during the early season (March-April) when high winds coincide with sowing of vegetable crops. Early-season wind erosion potential from soil-incorporated green manure (i.e. mustard) and no green manure treatments was assessed at two locations over two years using a portable wind tunnel. Incorporation of green manure the preceding autumn did not influence wind erosion or soil erodible characteristics the following spring. Soil-incorporated green manure, however, did influence early-season crop residue characteristics. Although differences were significant, low residue cover and stem silhouette area suggested relatively small differences in empirical estimates of windblown soil loss between manure treatments. Soil crusting resulting from irrigation and/or rainfall prior to assessing wind erosion may have masked any influence of green manure on wind erosion. Due to the high erosion rates measured from the crusted soils, multiple years of green manure or minimum or reduced tillage may be required to promote aggregation and/or enhance residue cover and thereby reduce wind erosion of irrigated soils.