Spatialising crop models

There are many incentives for applying a crop model on a regional scale, i.e. over an area larger than that for which it has been developed. This is what we call "spatialising" a crop model. These large areas can have very heterogeneous soil, climate and management practices. Consequently, spatialising a crop model can raise serious problems. One set arises from the fact that the basic concepts, hypotheses and validity domains of crop models are derived on the plot scale and may not apply on a larger scale. Another set arises from the lack of adequate and sufficient data to run the model on a regional scale. The workshop held in Toulouse (France) on 14-15 January 2002 dealt with the topic of spatialising crop models. The present paper is a comprehensive summary of the thoughts we had before, during and after the workshop.