Parameterization and evaluation of simple model for simulation of growth and yield of soybean in Tehran climatic condition

The goal of this study was using a simple model to investigate climatic factors, crop management and plant growth traits to simulate growth and yield of soybean in Tehran climatic condition in order to be use as an efficient tool to study effective factors on yield. The model was used in Tehran condition. Soybean is one of the important resources of herbal oil and protein. The affection trend of production and concentration of dry matter in vegetative parts and grains of soybean due to deviation of the parameters such as base temperature, the maximum observed leaf area index and fraction of crop total dry matter at the beginning of grain growth, was studied. Decrement and increment of base temperature caused to decrease and increase of phenological period and production of dry matter and the matter that was allocated to vegetative organs and grains. The increment and decrement of grain remobilized matter caused to enhance and decrease harvest index. Some achieved results based on differences between observed and simulated values were used to evaluate the model. The simulated yield ranges were within 1890-2220 with mean values of 1982.5 and the observed yield ranges were within 1632-2254 with mean values of 2014.5Kg per hectare. The RMSE was 178.48 Kg per hectare that was equal to 9 percent of average of observed and predicted values. All values were within the area of 80 percent of 1:1 line and the prepared model has suitable accuracy in prediction of soybean yield in Tehran climatic condition.