Lucerne (Medicago sativa L.) is a perennial legume with high importance as fodder crop under organic farming. Our study analyzes biomass growth and influence on soil water dynamics of three lucerne cultivars in a field experiment and using the simulation model CropSyst. The objective was to evaluate the model for a perennial legume crop, study the relation of cultivar traits with soil water relations and derive a lucerne ideotype for temperate, semi-arid conditions. Two cultivars of European origin (Sitel and Niva)were compared to an Iranian one (Mohajeran). Measurements were made under irrigated (non-water limited) and rain-fed (water limited) conditions. Sitel achieved a cumulative biomass (dry matter yield)of 36.8 t ha−1 (irrigated) and 25.3 t ha−1...
