Study On Summer Maize Growth Simulation Model Of Loess Areas

Crop growth simulation model is one of the most active domains in agricultural science. Studying on this domain create many conditions for the informationization of agricultural production. It has great significance in guiding agricultural production, increasing crop yield. Now, maize is the most widely distributed and one of the most important crops in the world. Yield of maize in developing countries is about 1/3 of the whole world. Our country is the biggest developing country and its planting area of maize is only less than America. Loess Areas are mainly dry-land agricultural region in north of China. So it is very important that studying on summer maize growth simulation model in loess areas.The farmland observation data, being the base of this research, are obtained at Irrigation Experimental Station of Northwest A&F University. This station is the representative of Loess Areas. The summer maize development model, embodying biochemistry and biophysics mechanism of crop growth, is established. The model based on the study results of crop model of other scientists, uses the equations which have been validated. This model mainly includes the biomass accumulated module and evapotranspiration simulated module and its time step is one day. Among them, growth process, photosynthesis, respiration costs, assimilation matter partitioning and translocation are considered in the biomass accumulated module; the dual crop coefficient approach which including the basal crop coefficient and soil evaporation coefficient is used in the evapotranspiration module.According to the field experimental data and meteorological data from the year 2004, the crop model parameter was estimated or optimized. Based on some hypothesis and simplify, this dissertation give the approach how to calculate the variation rule of summer maize LAI depended on highness of canopy, and give the experience formula according the experimental data. The biomass partition coefficients were optimized with the objective of minimum square errors between simulated and measured crop yield of experiment in this year.The primary meteorological factors'daily variation of 2004 and the dynamics of biomass accumulation on all of the organs and the dynamics daily evapotranspiration after the summer maize seeding in 2005 were used to validate the model. The results showed, except the very...