S12 - Session P3 - The development of a real-time irrigation decision tool for Asparagus

Authors: Noémie Hisette *, Joke Vandermaesen, Joris De Nies

The dry periods in combination with limited water resources at field level caused serious production losses in the Flemish and Dutch horticultural sector in the last years. As climate studies predict a higher frequency of longer dry periods with an average decrease of the rainfall in the summer, there is a need for efficient irrigation systems adapted to local growing conditions. A real-time irrigation decision tool is developed for drip-irrigated asparagus systems. The tool simulates the soil moisture content based on an Aquacrop-based soil water balance model, a crop growth and root growth model. Input parameters such as the water retention curve of the soil and the initial soil water content at field level are considered. During the growing season the model is fed with real-time weather data, groundwater level measurements and the supplied irrigation. In this case the simulated soil moisture content in the asparagus root zone was calibrated based on soil moisture samples and data from soil moisture sensors at 30cm, 60cm and 90cm depth. Data collected from three asparagus fields in Flanders and the Netherlands during two growing seasons were used for the model calibration. This allowed improvements of model parameters and biophysical process calculations. The irrigation decision tool contains a user interface where the model output is displayed. This includes the real-time simulated soil moisture content and the irrigation scheduling. Complementary, the user is also able to see the real-time data from volumetric soil moisture sensors and soil water potential sensors placed in his field. For now, the model does not use the data from the soil moisture sensor, but it can be a possibility in the future. The next step is to expand the irrigation decision tool to the blueberry cultivation.