Publications

The CERES-Maize model was developed to investigate how variations in environmental conditions, management decisions, and genetics interact to affect crop development and growth. A tile drainage subroutine was incorporated into CERES-Maize to improve soil-water and nitrogen leaching under subsurface tile drainage conditions. The purpose of this work was to evaluate the soil-water, soil-nitrogen, tile drainage, and tile-nitrogen loss routines of CERES-Maize for file-drained fields in Iowa. An analysis was conducted based on information collected from a study of 36 plots consisting of five management systems during a 4-year period from 1993 to 1996; at Nashua, IA. The model was calibrated for each plot using data from 1994 and 1995, and validated using data from 1993 and 1996. Temporal soil-water contents and water flow from tile drains were calibrated to an average root mean square error (RMSE) of 0.036 cm(3) cm(-3) and 2.62 cm, respectively, compared to measured values. validation trials gave an average RMSE for soil-water and tile drainage of 0.046 cm(3) cm(-3) and 5.3 cm, respectively. Soil-nitrate and tile-nitrogen flows were calibrated, with an RMSE of 6.27 mu g NO3 g(-1) soil(-1) and 3.21 kg N ha(-1) soil(-1), respectively. For the validation trials, the RMSE for soil-nitrate content and cumulative tile-nitrate flow was 6.82 mu g NO3 g(-1) soil(-1) and 8.8 kg N ha(-1), respectively. These results indicate that the new tile drainage algorithms describe water and nitrate movement reasonably well, which will improve the performance of CERES-Maize for artificially drained fields. © 2000 Elsevier Science Ltd. All rights reserved.