Title: The Evolution of RZWQM by Integrating System Modeling with Field Research
Presenter: Liwang Ma, USDA-ARS
Date: Tuesday, July 12, 2016
Time: 10:00-11:30 a.m.
Venue: Room 104, International Center

Abstract
The USDA-ARS Root Zone Water Quality Model (RZWQM) was initiated in 1985 in response to a need for better understanding of the physical, chemical, and biological processes in the root zone. It was initially developed mainly for the effects of agricultural management practices on environmental quality. The development team was closely collaborating with five MSEA (Management Systems Evaluation Areas) sites in the United States to address the agricultural issues facing the Midwest. The first version of the model was released in 1992 and a set of papers were published in 1999 as a result of the RZWQM-MSEA project. A Windows user interface was developed in 1998. To enhance the capability of crop production simulation, the CERES and CROPGRO crop models from the DSSAT (Decision Support Systems for Agrotechnology Transfer) were incorporated into RZWQM in 2005. Later additions to the model included the surface energy balance from SHAW (Simultaneous Heat And Water) and water erosion from GLEAMS (Groundwater Loading Effects of Agricultural Management Systems). Most recently, an automated parameterization algorithm of PEST (Parameter ESTimation) was incorporated into RZWQM for better model calibration. This seminar will present the history of RZWQM and how it has been used to integrate systems modeling with field research that benefits both model development and extension of field experimental results. 

Biography
Dr. Liwang Ma is a Research Soil Scientist with the USDA-ARS Agricultural Systems Research Unit in Fort Collins, Colorado. He earned his B. S. and M. S. degrees from Beijing Agricultural University (now China Agricultural University) in 1984 and 1987, respectively, and his Ph. D. from Louisiana State University in 1993. He joined the RZWQM team in 1996 and is now the main contact for RZWQM model users. He was elected Fellow of the American Society of Agronomy (ASA) and Soil Science Society of America (SSSA), and received the Environmental Research Award from ASA and L. R. Ahuja Ag Systems Modeling Award from SSSA.

Institute for Water Saving Agriculture in Arid Areas of China
College of Water Resources and Architectural Engineering
Institute of Soil and Water Conservation
July 8, 2016