Nutrient model

Hi grassers...

Does anybody know if there is a nutrient dynamics model written for
grass? The sort of thing I'm looking for is a simple process model that
takes a raster of elevations and simulates nutrient transfer between
cells over time, using the elevation difference between adjacent cells
as a rough estimate of the rate of transfer between them.

The whole thing can probably be written in about 200 lines of C I
imagine, but if someone has already done the job (or a better one, for
that matter), it would make my life a little easier.

Thanks in advance

David Houlder Phone: +61 6 249 4613
Geography Department (In Aust.: (06) 249 4613)
The Australian National University Fax: +61 6 249 3770
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