SUNDIAL is a dynamic computer model of nitrogen turnover in the crop/soil system. It incorporates current scientific knowledge on the individual processes of nitrogen turnover and integrates these processes to simulate what happens in the whole soil. SUNDIAL requires readily available information on soil type, cropping history and weather data as model inputs. It is widely used by scientists to interpret the results of field experiments, in particular the effects of crop management, soil type and different weather patterns on nitrate leaching (SUNDIAL the Research tool). SUNDIAL is also being developed into a Fertiliser Recommendation System (SUNDIAL-FRS), a management tool for farmers, growers and advisors, which will provide nitrogen fertiliser recommendations on a field-by-field basis, aiming to minimise nitrate leaching whilst achieving the desired yield.
SUNDIAL is a dynamic model with a weekly description of the effects of different weather patterns, soil and crop types on nitrogen turnover. SUNDIAL is designed to be used in a ‘carry-forward’ mode, with information from one years run providing inputs for the next. This allows it to investigate more complex systems involving rotations of crops and planning timescales of several years (modelling whole farm systems). SUNDIAL is also used in modelling nitrate leaching from whole catchments (catchment modelling).The SUNDIAL model can be used to predict nitrate losses by simulating the dynamics of nitrogen turnover in the soil/crop system. SUNDIAL-FRS can be used by farmers and advisors to devise a management strategy to minimise nitrate losses for individual farms.