Why model? Agricultural system models enhance and extend field research...to synthesize and examine experiment data and advance our knowledge faster, to extend current research in time to predict best management systems, and to prepare for climate-change effects on agriculture. The relevance of such models depends on their implementation. Methods of Introducing System Models into Agricultural Research is the ultimate handbook for field scientists and other model users in the proper methods of model use. Readers will learn parameter estimation, calibration, validation, and extension of experimental results to other weather conditions, soils, and climates. The proper methods are the key to realizing the great potential benefits of modeling an agricultural system. Experts cover the major models, with the synthesis of knowledge that is the hallmark of the Advances in Agricultural Systems Modeling series.

Dr. Laj Ahuja is a retired soil scientist at USDA in Fort Collins, CO.

Dr. Liwang Ma is a research soil scientist at the USDA-ARS Rangeland Resources and Systems Research Unit at Fort Collins. Dr. Ma's research interests include the use of system ecological and biophysical models to quantify agricultural production and environmental impacts at multiple spatiotemporal scales in rangelands and croplands.