Crop model: REGCROP

REGCROP is a regional dynamic agri-meteorological model geared towards modelling climate impact on biomass production of arable crops (Gobin, 2010, 2012). The physical basis relies on quantified relationships between weather and yield at the regional scale. Daily meteorological inputs and subsequent mathematical description of bio-physical crop growth processes allow for establishing climate-related stress occurrences during the growing season.

Phenological crop development is based on thermal time using planting dates and crop-specific upper and lower threshold temperatures, which form together with day length, the boundaries of phenological activity. The amount of solar radiation intercepted depends on the seasonal distribution of leaf area, the development of which relies on ambient temperature and moisture supply in both soil and atmosphere. The water balance is a single-layer varying size bucket model, adapted from Allen et al. (1998) to incorporate effects of reduced growth conditions due to water stress (drought, water logging) or heat stress (temperature , vapour pressure deficit) on crop growth. The projected CO2 fertilisation effect under climate change is weighted for the impact of adverse weather conditions.

The model has been used to calculate meteorological and climate impacts on Belgian arable yields at the field- to regional scale. The focus has been predominantly on time-series analysis and inter-annual comparisons. Comparisons between different Belgian agro-ecological zones will be part of the project.