Modeling Maize Growth And Yield In Siping Region By Considering Climate Change

This thesis based on field experiment analyzes the trends of climate change, crop growth and yield of Siping area in Northeast China, determines the parameters of the Root Zone Water Quality Model (RZWQM) through calibration and verification process; simulates the changes of maize water consumption and grain yield under different climatic conditions using meteorological data and test data, Results showed that:(1) It was found that precipitation, average relative humidity and average wind speed, sunshine and net radiation in study area showed a decline trend, while the average temperature and saturation water vapor pressure deficiency had an increasing trend. The climate in this region showed a gradually warming and drying tendency. The interannual variation of ETO was relatively flat, and it had been declining since 2000. The main factors that affect the ETO in the study area in the 6-8 months were sunshine hours and the temperature, and the temperature and wind speed were the main factors at other times.(2) RZWQM model was calibrated and verificated by using the meteorological data and test data of the study area, and the model parameters of seedling growth characteristics of P5, photoperiod sensitive coefficient of P2, filling characteristics parameters of P5, plant’s maximum number of grains per spike G2, G3 potential grain filling rate and leaf margin property parameters PHINT 380 were obtained, which were 0.34,720,590,11.0,48.2, respectively.(3) The temperature and precipitation were two important factors affecting the yield of spring maize in the study area. The correlation coefficients between the lowest temperature, the maximum temperature, the average temperature and the yield were 0.622,0.391 and 0.577 respectively on the 0.01 significance level. Total precipitation and precipitation distribution had an obvious effect on maize yield, which has high yield and change slightly when the precipitation is not less than 420 mm; the yield could gain maximum yield when the rainfall were greater than 125 mm,240mm and 130mm at jointing stage, pumping male grouting period and mature period, respectively. It has shown positive correlation between rainfall of pumping period and maize yield when the total amount of precipitation is less than 420 mm during the growth stage. So in order to guarantee the yield, the first step is to ensure the water quantity for spring maize of pumping male grouting period.(4) The optimum interval of maximum temperature, minimum temperature and average temperature were 26.1-26.5℃、15.6-16.4℃、20.7-21.1℃ respectively when the relationship between temperature and yield of spring maize was simulated by RZWQM model. Considering the interaction between the rainfall and temperature, the variation of yield showed that the optimum temperature of spring maize growing in the study area would remain essentially unchanged. To achieve high yield, precipitation during growing period of spring maize was at least 567.30mm, but the multi-year average precipitation in growth period of spring maize is 509.53mm.So in order to achieve high and stable yield in the study area, supplemental irrigation was needed.