SoySim - Soybean Growth Simulation Model

Soybean field
Soybean pod image
Soybean flower
Soybean pod green
Soybean pod dry
Soybean pod open with bean

The SoySim model simulates soybean growth on a daily basis from emergence to full maturity (R8). This version of the program simulates soybean yield potential and water use plus irrigation requirements under non-limiting conditions, assuming both optimal nutrient supply and no yield losses from abiotic and biotic factors.

SoySim had been validated at irrigated research and field sites in Nebraska, Iowa, and Indiana at which agronomic inputs were optimized to allow a full expression of yield toward yield potential. The results indicated that the model was able to simulate above ground and seed dry matter with reasonable accuracy compared to other existing models. SoySim achived desirable results even with far less cultivar-specific input parameters as compared to other models

More information for the model is provided in the SoySim User Manual

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Inputs, Processes, and Outputs of SoySim Model


For simulation of yield potential, the model requires daily weather data for solar radiation and maximum and minimum temperatures. For simulation of the water use and irrigation recommendation, the model requires daily weather data for solar radiation, maximum and minimum temperature, rainfall, reference evapotranspiration, and relative air humidity.

Overview and screen shots of SoySim model (click the picture to enlarge the view)

Overview Diagram
Input Page

Text Results

Summary Graph


Water User

Yield Comparisons

Weather Utility

SoySim Model Developers:

Tri D. Setiyono1
Kenneth G. Cassman1
James E. Specht1
Albert Weiss2
Achim Dobermann3

1 Dept. of Agronomy and Horticulture, University of Nebraska
2 School of Natural Resources, University of Nebraska
3 International Rice Research Institute, Philippines

Funding for SoySim model development was provided by:

The Nebraska Soybean Board1
The Fluid Fertilizer Foundation1
The Foundation for Agronomic Research1
The International Plant Nutrient Institute1
The Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska.1

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