Quoted from: Stöckle, Claudio O., Marcello Donatelli, and Roger Nelson. "CropSyst, a cropping systems simulation model." European journal of agronomy 18, no. 3-4 (2003): 289-307. https://doi.org/10.1016/S1161-0301(02)00109-0
CropSyst is a multi-year, multi-crop, daily time step cropping systems simulation model developed to serve as an analytical tool to study the effect of climate, soils, and management on cropping systems productivity and the environment. Emphasis has been placed on developing a user-friendly interface, providing links to GIS software, a weather generator, and other utility programs.
CropSyst simulates the soil water budget, soil-plant nitrogen budget, crop phenology, canopy and root growth, biomass production, crop yield, residue production and decomposition, soil erosion by water, and salinity. These processes are affected by weather, soil characteristics, crop characteristics, and cropping system management options including crop rotation, cultivar selection, irrigation, nitrogen fertilization, soil and irrigation water salinity, tillage operations, and residue management.
The development of CropSyst started in the early 1990s. The motivation for its development was based on the observation that there was a niche in the demand for cropping systems models, particularly those featuring crop rotation capabilities, which was not properly served. Efficient cooperation among researchers from several world locations, a free distribution policy, active cooperation of model developers and users in specific projects, and careful attention to software design from the onset allowed for rapid and cost-effective progress. Another important factor was the advantage of learning from a rich history of crop modeling efforts.
The first examples of crop growth models, mostly intended for use by the agriculture research community, were available during the 1970s (e.g. de Wit et al., 1970, Arkin et al., 1976). Applications oriented to management or field decision-making (irrigation scheduling, pest and disease control, etc.) appeared in the early 1980s (e.g. Wilkerson et al., 1983, Swaney et al., 1983). On-farm applications of models were also reported (e.g. Lindemann et al., 1987, McKinion et al., 1988). Models such as SUCROS and others associated with the ‘School of de Wit’ (Bouman et al., 1996) as well as those of the CERES (Ritchie et al., 1998) and CROPGRO (Boote et al., 1998) families of models had a significant impact on the crop modeling community.
For the analysis of cropping systems, the ability to simulate crop rotations is important. Models of the CROPGRO and CERES families, placed under the common umbrella of DSSAT (Jones et al., 1998) can be used in rotation configurations. However, the DSSAT approach has been slow in adopting a more generic simulation platform that would allow users to easily integrate these models and simulate crop rotations (Jones et al., 2001). The EPIC model (Williams et al., 1984) provides a simple but effective generic multi-crop simulation approach suitable for the analysis of crop rotations and cropping systems. However, the model has limitations due to the simplicity of its crop growth descriptions and related biophysical processes.
CropSyst was designed to draw from the conceptual strengths of EPIC, but including a more process-oriented approach to the simulation of crop growth and its interaction with management and the surrounding environment. In addition, a stronger emphasis on software design was a clear departure from the EPIC and DSSAT approaches. Attention to a balance between the incorporation of sound science in the models and the utilization of adequate software design practices has been a trait of CropSyst since the beginning of its development. In this regard, it shares somewhat common objectives with APSIM (McCown et al., 1996, Keating et al., 2003), a modeling approach that has evolved to place substantial resources in the development of quality software engineering practices.