Online decision support for irrigation for farmers

Online decision support for irrigation has been available in Denmark since 1996. This paper describes an Internet implementation of a previous stand-alone PC-program; the Internet version has undergone several modifications and upgrades. The system has a morphological model for crop development based on temperature sums, and a hydrological model for calculating soil water balance. Weather data are supplied automatically from weather databases, precipitation data can be overrode by user inputs. Users can initiate the system with data on fields and crops, and add data on irrigations. Irrigation advice and explanation are provided in tables and graphics. The system had 322 active users in 2004 and 490 in 2005.