Study On Simulation Model Of Developmental Stages For Major Crops In Henan Province

Winter wheat and summer maize are the main food crops in Henan Province. Henan Province affected by the monsoon climate and terrain transition zone, the climate disasters frequently occurred which made a direct impact on the production of food crops. Crop yield formation is a dynamic process and the growth and development of the crops play a significant role in determining the potential yield. Real-time grasp of crop development process can provide useful information and scientific basis for the field management of each growth stage, which is of great significance to ensure the food production. On the basis of the previous study on the crop development models, this paper adopted the physiological development time theory and the concept of climate suitability to establish the winter wheat and summer maize growth simulation models, respectively.1、According to the physiological development time constant principle, three non-linear models in terms of crop growth temperature effect including two versions of Beta models and a Sine model were commonly introduced and compared. The predicted developmental stages included emergence stage, green-turning stage, jointing stage, heading stage, flowering stage and maturity stage. Model evaluation for winter wheat was based on a set of four-year independent data. The simulated results showed that (1)no significant improvement in the prediction of the developmental stages using the Sine model was found as compared to two Beta models and (2)The Sine model generally produced a more reasonable set of cardinal temperatures than the two Beta models after green-turning.2、It is the first time to introduce climate suitability method into the summer maize growth simulation model. The temperature suitability function, precipitation suitability function and sunshine suitability function, respectively, were established in this model. The affecting weight coefficient for temperature, precipitation or sunshine during different development stages was derived from analyzing the influence of each meteorological factor on the duration of development stage. The combined suitability was calculated by the weighted average method for predicting the summer maize growth. Model evaluation for summer maize was based on a set of three-year independent data. The results showed that the model can predict various development stages well (emergence, seven-leaf, jointing, tasseling, milk stage and maturation). The regression estimated standard error RMSE values between the simulated and observed values of independent data were in1～4.6days.The growth simulation model of winter wheat established in this paper had high predictive ability and practical application. Because these models were all developed based on the thermal effects and Henan Province is representative of winter wheat growing conditions in a large portion of Huang-Huai-hai plain of China, they can be easily extended to simulate development of cereal crops in other areas with modification of the three cardinal temperatures. Base on the climate suitability theory, the growth simulation model of summer maize comprehensively considered the effects of the temperature, precipitation and sunshine on the crop growth and development, with highly rational, which provided a better way for further study on crop growth simulation.