Submitted to: Soil and Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2012
Publication Date: 12/1/2012
Publication URL: http://handle.nal.usda.gov/10113/56864
Citation: Singh, P., Sharratt, B.S., Schillinger, W. 2012. Wind erosion and PM10 emission affected by tillage in the world’s driest rainfed wheat region. Soil and Tillage Research. 124:219-225. Interpretive Summary: In the Horse Heaven Hills of eastern Washington where wheat-fallow is the dominate crop rotation, the soil is cultivated multiple times during the fallow phase of the rotation to conserve soil water for the next wheat crop. This intensive tillage practice causes extensive wind erosion of the land. Alternate and less invasive tillage practices are sought that will reduce wind erosion. Wind erosion was reduced by using conservation undercutter tillage rather than conventional tillage practices. A viable option for wheat growers to reduce wind erosion in the Horse Heaven Hills is to use undercutter tillage.
Technical Abstract: The Horse Heaven Hills of south-central Washington is the driest rainfed wheat growing region in the world. Low precipitation, high winds, poorly aggregated soils, sparse residue cover, and a tillage-based winter wheat (Triticum aestivum L.) – summer fallow (WW-SF) cropping system often combine to create surface conditions susceptible to wind erosion. No-tillage summer fallow (NTF) and conservation tillage fallow (CTF) with an undercutter sweep implement were examined as alternative practices to traditional tillage fallow (TTF) with a tandem disk implement for reducing wind erosion and PM10 (particulate matter less than or equal to 10 µm in aerodynamic diameter) emissions during the fallow phase of the WW-SF rotation. Wind erosion and PM10 emissions were assessed with a wind tunnel after primary spring tillage in mid-to-late April and after sowing winter wheat in August. Sediment loss and PM10 vertical flux and loss were generally less for NTF than with TTF, likely due to retention of surface residue and maintaining a soil crust in NTF. Sediment and PM10 loss increased after sowing wheat in both the TTF and CTF treatments. Sediment and PM0 loss were lowest for NTF, but this method is not yet an economical option for most growers in the region. Conservation tillage fallow using the undercutter sweep is an economically viable alternative to TTF for reducing windblown sediment and PM10 loss from agricultural soils in the Horse Heaven Hills.