|PI, HUAWEI - Washington State University|
Submitted to: Aeolian Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2019
Publication Date: 8/8/2019
Citation: Pi, H., Huggins, D.R., Sharratt, B.S. 2019. Dry aggregate stability influenced by soil type, crop rotation, soil amendment, and tillage in the Columbia Plateau. Aeolian Research. 40:65-73. https://doi.org/10.106/j.aeolia.2019.07.001.
Interpretive Summary: Dry aggregate stability defines the strength of an aggregate and thus influences the susceptibility of soils to wind erosion. The stability of aggregates has been measured in the Great Plains of the USA, but not in the Pacific Northwest where wind erosion significantly degrades air quality. Dry aggregate stability was greater for soils that were managed using conservation or no tillage compared with conventional tillage practices and from winter wheat-oilseed-summer fallow rotation compared with a winter wheat-summer fallow rotation. Aggregates were more stable for tillage and cropping practices that retained more crop residue on the soil surface, thus farmers are encouraged to use practices that maximize crop residue retention for enhancing the stability of soil aggregates and reducing soil erosion.
Technical Abstract: Dry aggregate stability (DAS) is an important factor influencing soil erodibility and tillage. We investigated the effect of soil type, crop rotation, soil amendments, and tillage on DAS across the Inland Pacific Northwest United States. Stability of dry aggregates was measured using a commercial penetrometer. Significant differences in DAS were found between tillage treatments at a site in south-central Washington. DAS at this site was 60 to 89% higher for no-tillage summer fallow than tillage-based summer fallow treatments. DAS for winter wheat-camelina-summer fallow (WW-C-SF) or winter wheat-safflower-summer fallow (WW-S-SF) rotations was consistently higher than a winter wheat-summer fallow (WW-SF) rotation at two sites in central Washington. In contrast, green manure or biosolids as an amendment did not appear to influence DAS. DAS was more closely related to clay content than other soil properties (i.e. geometric mean aggregate diameter and surface area of primary particles). Clay content can therefore be used to estimate DAS of soils in the Inland Pacific Northwest.