  Employing an effective cellular automata model, we investigate and analyze
the build-up and erosion of soil. Depending on the strategy employed for
handling agricultural production, in many cases we find a critical dependence
on the prescribed production target, with a sharp transition between stable
production and complete breakdown of the system. Strategies which are
particularly well-suited for mimicking real-world management approaches can
produce almost cyclic behaviour, which can also either lead to sustainable
production or to breakdown. While designed to describe the dynamics of soil
evolution, this model is quite general and may also be useful as a model for
other renewable resources and may even be employed in other disciplines like
psychology.
