Soil Evaluation Based on Simulation by a Model

Abstract Soil qualities have been estimated by simulation with a continuous dynamic plant growth model named “Heimdal”, which in particular describes the water movement and envergy state in the soil-plant-atmosphere system. Root development of barley, soil water characteristic curves and the sequence of horizons in the profiles were field determined data inputs. As climatic data, a mean drought period of June in Denmark was used. The duration of simulation was at least 25 days, and the time interval was 0.002 day. Two sandy and two clayey profiles were investigated. The data output variables were the maximum daily traspiration rate, the leaf water potential at midday and midnight, the rate of actual and potential traspiration, the accumulated traspiration, and dry matter production. As the simulation showed that plant growth was only slightly reduced due to water stress—as long as the ratio between actual and potential transpiration was above 0.7—the evapotranspiration until this value was reached is sugg...