Summer Maize Radiative Transfer And Dry Matter Simulation

Maize is the world's most important food and feeding crops,also it is China's second largest food crops.But in recent years due to water stress and rural planting structure adjustment,causes the corn planting area began to decline year by year.This paper studied the summer maize water consumption and radiative transfer model and dry matter accumulation was based on the two years measured data.The main results are as follows:1.According to the measured data from the local weather station,the author analyzed the change of the growth environment factors during the whole growth period of summer maize,and analyzed the reason for difference of the leaf area between the two years based on the measured leaf area index.Using the modified single crop coefficient method combined with meteorological data to calculate the changes in summer corn evaporation in the region,and according to the change of the total evaporation,verify the single crop coefficient of the modified method to calculate the effectiveness of summer corn evaporation in the region.2.The sunscan canopy analyzer was used to measure the distribution of radiation in the canopy under different growth stages at same time series and same growth stages at different time series in the typical sunny days,then the measuring results were compared with the simulation results of model,The results showed that the model has a suitable simulation effect on the radiation distribution at different growth stages at different time series.The average error between the simulated value and the measured value is quite small and the mean square root error is also small.However,due to the model neglects the difference between the diffuse reflection effect of leaves for the summer maize,the simulated value is slightly smaller than the measured value,which is more obvious in the lower part of the canopy.3.Based on the established model of photosynthetic active radiation for canopy,by measuring the photosynthesis-light response curve of whole growth period and using the mathematical relationship of light intensity and photosynthetic rate in the right angle hyperbolic correction model,the photosynthetic rate model of single leaf was established.The leaf scale is transformed into canopy scale by the difference of weight in Gaussian integral method,then the dry matter accumulation model of summer maize was established by combining the existing crop respiration model.It is found that the model simulation results are in good agreement with the measured data based on the measured data of dry matter in the whole growth period.