Constructing a nitrogen fertilizer recommendation system around the dynamic nitrogen turnover model, SUNDIAL

Abstract: An effective fertilizer recommendation system requires information on seasonal variations in soil mineral nitrogen and nutrient requirements of the crop. This can be provided by the dynamic model, SUNDIAL (Bradbury, et al, 1993; Smith, et al., 1996). Work presented here formalises farmers' requirements into a system prototype. Inputs should be entered both by menu and tabular format, have user-selected units, be supported by context-sensitive help, and be compatible with commonly used farm recording packages. Recommendations should be provided both for the field and across the whole farm. Turnover processes should be illustrated graphically.