Modeling, Experimentation, Verification and Validation: Closing the Feedback Loop
ABSTRACT DYNAMIC-SYSTEM simulation as applied to crop systems is defined and explained in connection with the prediction of crop growth and yield. Experimental procedures and facilities for obtaining the data base pe-culiar to process-level models are also dilineated. The ab-solute need for model verification and validation before use is also discussed. Finally, the interrelation of the four preceding processes in a positive feedback manner which results in an amplificaiton of the research process is also discussed.