Monday, 7 November 2005
2

Wind Erodibility of Soil in a Dryland Wheat-Fallow Cropping System.

Laura Wendling, USDA Agricultural Research Service, PO Box 646120, Pullman, WA 99164-6120, Brenton Sharratt, USDA-ARS, 213 LJ Smith Hall, WSU, Pullman, WA 99164-6120, and Guanglong Feng, Biological Systems Engineering Dept., PO Box 646120, Washington State University, Pullman, WA 99164-6120.

Agronomic practices in the conventional wheat-fallow region of central Washington State traditionally entail the use of multiple passes with tillage implements during the fallow cycle to create a dust mulch layer, the purpose of which is to retard the loss of soil moisture and to manage weed populations. High winds and low rainfall during the summer and early autumn create conditions optimal for wind erosion of soil. Windblown dust originating from agricultural fields is the primary source of PM10 (particulate material £10µm in diameter) contributing to poor air quality in the region. Less intensive tillage practices are sought that will reduce PM10 emissions and improve air quality while maintaining agricultural productivity. The objective of this study is to quantify PM10 emissions from soil during a simulated wind event following a sequence of various tillage operations. Experimental plots were established in winter wheat stubble on a silt loam soil near Lind, Washington, where the mean annual precipitation is approximately 244 mm. A sequence of tillage operations were performed after harvest in the autumn and in the spring and summer. Autumn tillage included the use of either a noninversion undercutter or a sweep implement, and a control treatment without any postharvest tillage. Spring tillage treatments involved using the undercutter, sweep, or cultivator implements. Rodweeding was performed throughout the summer as necessary for weed control. A portable wind tunnel was used to assess PM10 emissions over a known surface area in field plots following each tillage operation. Differences in PM10 emissions among post-harvest tillage treatments were apparent. These differences in PM10 emissions among tillage treatments became more pronounced following spring and summer tillage operations.

Back to Soil Erosion--Processes, Assessment, and Control: I
Back to S06 Soil & Water Management & Conservation

Back to The ASA-CSSA-SSSA International Annual Meetings (November 6-10, 2005)