A forage brassica simulation model using APSIM: Model calibration and validation across multiple environments

Forage brassicas have historically been used in high rainfall/irrigated temperate livestock systems, but there is increasing interest diverse forage drier mixed crop-livestock farming systems. Computer-based modelling an important decision support tool agriculture to explore the adaptability of crops different climates and agronomic management practices, existing tools for are limited environments. We parameterised APSIM (Agricultural Production Systems Simulator) model four brassica genotypes, including three rape cultivars a raphanobrassica. The was calibrated using two experiments with repeated measures biomass components, nutritive value, leaf canopy development. then tested extensively data from set environments within Australian New Zealand (23 sites across agro-climatic zones). Model predictions were good all genotypes (NSE > 0.60, Nash-Sutcliffe efficiency; RMSE ~1.5 t DM/ha, root mean square error). Predictions metabolisable energy yield satisfactory 0.43–0.73; ~17.8 GJ ME/ha) dry matter digestibility (DMD) poorly predicted due small variation observed data. Our robust widely can be confidently predict productivity common new wide range production practices. This will enable future work develop better understanding potential value these