Test of a modelling system for simulating water balances and plant growth using various different complex approaches

In this paper, a modelling system that integrates various complex model com ponents for the purposes of water balance modelling and crop growth simulat ion is presented. These components are modules for calculating potential an d actual evapotranspiration, crop growth and soil water balance. Two differ ent complex simulation models obtained from the modelling system were teste d using field data from two arable test sites. The modelling results show t he ability of this modelling system to simulate water balance and crop grow th with acceptable precision. Additionally, the impact of a recombination o f the two simulation model components on the simulations of the field data was analyzed. These recombinations include an exchange of the soil water ba lance modules, the crop-growth models and the formulae for calculating pote ntial evapotranspiration. This analysis indicates that the type of soil wat er model used is the most essential consideration for simulating the dynami cs of soil water contents and percolation. The exchange of crop models and the use of different modules for calculating potential evapotranspiration a ffect evaporation, transpiration and interception. The impact of these rear rangements on soil water dynamics was less significant than the effects fro m the different soil water models. (C) 2000 Elsevier Science B.V. All right s reserved.