During the last 20 years rapid progress has been made in the simulation of agricultural processes. A number of models are now available to simulate processes such as weather, hydrology, nutrient cycling and movement, tillage, soil erosion, soil temperature, and crop growth and development. Many of these models are quite restricted in purpose, simulating only discrete processes such as denitrification, leaching of NO3, soil temperature, or the movement of water in the soil. Others integrate several of these processes. During the last few years more comprehensive agricultural simulation models have begun to appear. These models simulate a number of processes and predict their interacting effects on crop growth and yield. As more and more processes are simulated, model development and testing require the expertise of an increased number of scientific disciplines and more teamwork and organization. Modeling comprehensive agricultural systems is rapidly becoming a team effort involving scientists around the world and demanding well-integrated networks to exchange both experimental data and software.
This book provides the documentation, testing, and software of CERES-Maize, a quite comprehensive model of maize (Zea mays L.) growth and development. Two versions of the model are provided. The standard version considers the independent and interacting effects of genotype, weather, and hydrology. The nitrogen version considers those factors as well as nitrogen nutrition. The development of the Crop-Environment Resource Synthesis (CERES) Maize model was coordinated by Dr. J. T. Ritchie at the Grassland, Soil and Water Research Laboratory of the United States Department of Agriculture, Agricultural Research Service (USDA-ARS). Dr. Ritchie was responsible for the conceptual development o f the model as well as many of the subroutines and much of the detailed FORTRAN code. However, he was aided by a large, informal network of experimental scientists and modelers from throughout the world. These cooperators are acknowledged in the text, but it is appropriate to point out here that their ideas, data, and constructive suggestions were indispensable.
Shortly before completion and final testing of the CERES-Maize model, Dr. Ritchie left ARS for a position at Michigan State University. Final modifications and testing were completed by the editors. .....................................