Crop simulation models are composed of algorithms that represent different
processes. These processes may include gross assimilation, respiration,
transpiration, soil evaporation, crop development, growth of leaf area,
senescence of leaf area, plant height, translocation of stored reserves,
number of reproductive organs, mass of the reproductive organs, growth of
roots, uptake of nutrients, partitioning of dry matter to above and below
ground components, etc. There isn't a way to simulate any of these
processes; there are several ways. Is one way superior to another way? Why?
How were the algorithms that simulate these processes developed? Or, where
do all the things on the left hand side of the equal sign come from? Does
this way provide valid, consistent results across different environments?
How can simulation of these processes be improved?
         I am contemplating organizing a symposium for the next American
Society of Agronomy meetings to address these issues. A tentative title for
this symposium is "Simulating crop responses; what do we know, why do we
know it, and where do we go from here". If you would like to make a
presentation to address any of these processes, please provide me a title.
The first four areas above have been addressed in greater detail than the
remaining areas. In order for a successful presentation, I think it is very
important to be honest and state this is what we know with confidence,
these are reasonable assumptions, and these are guesses. If you have any
questions or comments, please do not hesitate to contact me. Please feel
free to pass this message on to anyone you feel might be interested in this
area. Thanks for your help.
         Albert Weiss