Where do the simulations come from?
The crop yields stored in the Whopper Cropper database were simulated using the APSIM cropping systems modelling environment. APSIM has emerged from the combined efforts since 1990 of a large team of scientists from the Agricultural Production Systems Research Unit (APSRU), a joint initiative of DPI, DNR and CSIRO.

APSIM is a daily time step model that mathematically reproduces the physical processes occurring in a cropping system. APSIM is the most detailed and precise model of this kind in the world. Whopper Cropper provides crop management advisers with access to the power of the APSIM model, without spending time learning to use APSIM itself.

To create the Whopper Cropper database, a team of researchers from the APSRU and QCCA used the APSIM model to simulate a variety of cropping scenarios with different starting soil conditions and management options. Each combination of region, crop, sowing date, starting soil conditions, etc., defines a single simulation. The Whopper Cropper database contains about 150 000 of these simulations. Each simulation corresponds in length with the historical climate records available for that region. Most simulations in the Whopper Cropper database are over 100 years long.

The powerful predictive ability of the APSIM model means that Whopper Cropper can be used to explore What if? questions.