Lajpat (Laj) R. Ahuja is a supervisory soil scientist and research leader of the USDA-ARS, Great Plains Systems Research Unit, Fort Collins, Colorado. He has made original and pioneering research contributions in several areas of agricultural systems: infiltration and water flow in soils, estimation of hydraulic properties, and scaling of their spatial variability; transport of agrochemicals to runoff and to groundwater through soil matrix and macropores; quantification of the effects of tillage and other management practices on above properties and processes; and modeling of the entire agricultural systems and application of system models in field research, technology transfer, and management decision support., As development team leader, Ahuja guided the development, validation, and publication of the ARS Root Zone Water Quality Model (RZWQM), that is being widely used for evaluating effects of management on water quality and crop production. The Unit team has also developed a whole farm/ranch decision support system, GPFARM, for evaluating production, economics, and environmental impacts of alternative management systems., Ahuja has authored or co-authored more than 200 publications; he is also senior editor of the book on RZWQM. He has served as associate editor (1987 to 1992) and technical editor (1994 to 1996) of the Soil Science Society of America Journal. He is an invited guest editor of an upcoming special issue of Geoderma on "Quantifying Agricultural Management Effects on Soil Properties and Processes," has served as advisor and consultant to several national and international organizations, and has organized several interagency/international workshops.
Ahuja won the USDAARS, Southern Plains Area, Scientist of the Year Award in 1989. He was elected Fellow of the Soil Science Society of America in 1994 and the American Society of Agronomy in 1996., Liwang Ma is a soil scientist with USDA-ARS, Great Plains Systems Research Unit, Fort Collins, Colorado. Dr. Ma received his B.S. and M.S.
in biophysics from Beijing Agricultural University (now China Agricultural University) in 1984 and 1987, respectively, and his Ph.D. in soil physics from Louisiana State University in 1993. He is co-editor of three books and author or co-author of 50 publications. His research on agricultural system modeling extends from water and solute transport, to carbon and nitrogen dynamics, to plant growth. Dr. Ma is the recipient of the 1994 Prentiss E. Schilling Outstanding Dissertation Award in the College of Agriculture at Louisiana State University, Baton Rouge.
He is now serving as associate editor for the Soil Science Society of America Journal., Terry A. Howell is an agricultural engineer and research leader of the USDA-ARS, Water Management Research Unit at Bushland, Texas. He is noted for irrigation scheduling and evapotranspiration research, and for his original contributions on the design theory for drip irrigation laterals, design parameters for drainage systems based on crop performance, improved understanding of crop yield-water use relationships, use of remote weather stations to provide real-time irrigation scheduling information, improved weighing lysimeter designs for both reconstructed soil profiles and monolithic soil profiles, the importance of advective influences on evaporation in the Southern Great Plains, and improved understanding of the dynamics of irrigation application and efficiency of center-pivot and lateral-move sprinkler systems with various application methods. In particular, Howell led in developing and supplying the research data used in the North Plains ET (evapotranspiration) Network, which has been recognized by the State of Texas (1999 Environmental Excellence Award from the Texas Natural Resource Conservation Commission as well as the Governor of Texas and the Texas Legislature; the Texas A&M University Vice Chancellor''s Award for Excellence in Research); a separate Federal Agency (the 1999 Federal Energy Management and Water Conservation Award from the U.S. Department of Energy); by ARS (1999 ARS Technology Transfer Award); and by the Federal Laboratory Consortium (the 2000 Mid-Continent Regional Laboratory Award for exceptional support and encouragement to the transfer of federal technologies to the private sector)., Howell is a Fellow of the American Society of Agricultural Engineers (1992) and the American Society of Agronomy (1999).
He received the Person of the Year Award in 1995 from the Irrigation Association, the Royce J. Tipton Award in 1998 from the American Society of Civil Engineers, the Hancor Soil and Water Engineering Award in 2000 from the American Society of Agricultural Engineers, and the Senior Scientist Award for the Southern Plains Area from USDA-ARS in 2000.