Paper Withdrawn

Tuesday, November 14, 2006 - 12:55 PM
196-1

Impact of Long-Term Conservation Tillage Cropping Systems on Soil Hydraulic Properties in the Pacific Northwest.

Guanglong Feng, Biol. Sys. Engineering Dept, Washington State Univ, Pullman, WA 99164-6120 and Charles Carroll, Mycogen Seeds, 9635 East 1800 North Rd., Graymont, IL 61743.

Soil erosion driven by water and wind has long been a serious problem, which significantly affects water, air and soil quality in the Pacific Northwest. Maintaining proper soil physical and hydraulic properties can minimize soil water and wind erosion. Soil properties can be manipulated through tillage and crop residue management. Conservation tillage practices is an effective method to alter soil physical and hydraulic properties, and reduce the exposure of the soil surface to the forces of wind and water, therefore, can minimize the adverse effects associated with loss of top soil. The first long-term, field scale, conservation tillage cropping systems experiment was initiated at Ralston, WA in 1995. The experiment includes three treatments: winter wheat/summer fallow, spring wheat/chemical fallow, and continuous direct seed spring barley/spring wheat. The Long-term experiment provides an opportunity to assess the impact of conservation tillage systems on soil properties. However, soil hydraulic properties have not been examined in this experiment. The objective of this study was therefore to characterize infiltration, water retention, and saturated hydraulic conductivity of a soil 10 years after establishing tillage treatments in the Pacific Northwest. Soil properties were measured in April 2006; infiltration was measured using a double-ring infiltrometer, saturated hydraulic conductivity was measured by the falling-head method, and water retention was assessed by measuring the temporal variation in-situ soil water content.