Models for the thermal degradation (or pyrolysis) of solid fuel are fundamental to the physics-based simulation of grassfires. The pyrolysis process affects the combustion process and therefore the simulated flame, which defines the fire front. There are two competing models: a simple linear parameterisation and a non-linear Arrhenius model. The present work appraises these two models for Lucerne hay (a cured herbaceous fuel) to test their suitability for bushfire simulation. Thermogravimetric analysis and differential scanning calorimetry of Lucerne hay is conducted to measure the parameters required for the simulation. Simulations of pyrolysis are carried out using both the linear and single effective Arrhenius models, and compared with the experimental results. For this fuel, the linear model provides better agreement with the experimental data than the Arrhenius model. Hence, the linear model would