Simulating maize (Zea mays L.) growth and yield, soil nitrogen concentration, and soil water content for a long-term cropping experiment in Ontario, Canada

A performance assessment of the Decision Support Systems for Agrotechnology Transfer (DSSAT) model (v4.5) including the CERES-Maize and CENTURY modules was conducted for continuous maize production under annual synthetic fertilization (CC-F) and no fertilization (CC-NF) using field data from a long-term (53-yr) cropping experiment in Ontario, Canada. The assessment was based on the accuracy with which DSSAT could simulate measured grain yield, above-ground biomass, leaf area index (LAI), soil inorganic nitrogen concentration, and soil water content. Model calibration for maize cultivar was achieved using grain yield measurements from CC-F between 2007 and 2012, and model evaluation was achieved using soil and crop measurements from both CC-F and CC-NF for the same 6-yr period. Good model-data agreement for CC-F grain yields was achieved for calibration (index of agreement, d-0.99), while moderate agreement for CC-NF grain yields was achieved for evaluation (d-0.79). Model-data agreement for above-ground biomass was good (d-0.83-1.00), but the model consistently underestimated for CC-F and overestimated for CC-NF. DSSAT achieved good model-data agreement for LAI in CC-F (d-0.82-0.99), but moderate to poor agreement in CC-NF (d-0.46-0.64). The CENTURY module of DSSAT simulated soil inorganic nitrogen concentrations with moderate to good model-data agreement in CC-F (d-0.74-0.88), but poor agreement in CC-NF (d-0.40-0.50). The model-data agreement for soil water content was moderate in 2007 and 2008 for both treatments (d-0.60-0.76), but poor in 2009 (d-0.46-0.53). It was concluded that the DSSAT cropping system model provided generally good to moderate simulations of continuous maize production (yield, biomass, LAI) for a long-term cropping experiment in Ontario, Canada, but generally moderate to poor simulations of soil inorganic nitrogen concentration and soil water content.