CSM-IXIM: A New Maize Simulation Model for DSSAT v4.5

LIZASO, J.I.; BOOTE, K.J.; JONES, J.W., ; PORTER, C.H.; ECHARTE, L., ; WESTGATE, M.E., ; SONOHAT, G.

AGRONOMY JOURNAL

AMER SOC AGRONOMY

Año: 2011 vol. 103 p. 766 - 779

0002-1962

The CERES-Maize model is the most widely used maize (Zea mays L.) model and is a recognized reference for comparing new developments in maize growth, development, and yield simulation. The objective of this study was to present and evaluate CSM-IXIM, a new maize simulation model for DSSAT version 4.5. Code from CSM-CERES-Maize, the modular version of the model, was modified to include a number of model improvements. Model enhancements included the simulation of leaf area, C assimilation and partitioning, ear growth, kernel number, grain yield, and plant N acquisition and distribution. The addition of two genetic coefficients to simulate per-leaf foliar surface produced 32% smaller root mean square error (RMSE) values estimating leaf area index than did CSM-CERES. Grain yield and total shoot biomass were correctly simulated by both models. Carbon partitioning, however, showed differences. The CSM-IXIM model simulated leaf mass more accurately, reducing the CSM-CERES error by 44%, but overestimated stem mass, especially after stress, resulting in similar average RMSE values as CSM-CERES. Excessive N uptake after fertilization events as simulated by CSM-CERES was also corrected, reducing the error by 16%. The accuracy of N distribution to stems was improved by 68%. These improvements in CSM-IXIM provided a stable basis for more precise simulation of maize canopy growth and yield and a framework for continuing future model developments.