Education:

• 1987: South Dakota State University, Brookings, SD., B.S. Agricultural Engineering.
• 1989: South Dakota State University, Brookings, SD., M.S. Agricultural Engineering.
• 1995: Iowa State University, Ames, IA., PhD. Agricultural & Biosystems Engineering.
• 1999: Registered Professional Engineer in Idaho.

Experience:

• 1995-present: Agricultural Engineer, USDA-ARS, Northwest Irrigation and Soils Research Laboratory, Kimberly, ID.

Professional Societies:

• American Society of Agricultural Engineering
• American Society of Civil Engineering
• Soil Science Society of America
• Council for Agricultural Science and Technology

Accomplishments:

The main research focus has been soil erosion from irrigated land. The WEPP (Water Erosion Prediction Project) model was evaluated for predicting furrow irrigation erosion. This evaluation showed that the model could not be used for furrow irrigation without adjusting default erodibility parameters in the model and the model did not predict any sediment deposition even though deposition was measured in the field. Collaborative field and laboratory research showed that applying PAM with sprinkler irrigation improves infiltration and reduces soil loss. Collaborative research on sediment and phosphorus transport in furrow irrigated fields has shown that total phosphorus concentration directly relates to sediment concentration while dissolved phosphorus concentration decreases with time and increases with sediment detachment and furrow distance.

Research

Current Research

• Measure irrigation return flow water quantity and quality for the Conservation Effects Assessment Project (CEAP).
• Sediment and phosphorus transport with furrow irrigation.
• Cooperative project with US Water Conservation Lab in Phoenix to simulate phosphorus transport in surface irrigation runoff.
• Develop and evaluate tillage and erosion control practices for sprinkler and furrow irrigation.
• Measure soil erosion and erodibility to evaluate and improve simulation models.
• Evaluate amendments to reduce soluble phosphorus in irrigation return flow.

Expertise and Scientific Interests:

• Soil erosion on irrigated land
• Polacrylamide (PAM) application with sprinkler and surface irrigation
• Irrigation return flow and water quality
• Surface and sprinkler irrigation management
• Conservation tillage