The Simulation Analysis Of Wheat Yield Forming To Response Of Precipitation

In order to explore different precipitation years of precipitation on the wheat yield and yield components of influence mechanism,used APSIM model simulated different precipitation years of wheat yield and yield components. Debugged and verification APSIM model based on field experiment. Used APSIM model simulated dynamic variables of different precipitation years in wheat yield and yield components, and studied the relationship between different precipitation year of wheat yield and yield components used regression analysis, correlation analysis and path analysis. The main conclusions are as follows:1. APSIM model can be more accurately simulate the dynamics of different precipitation years in wheat yield and formation, this model can be used to guide crop production and optimizing management. Test results: the coefficient of determination R2 of Wheat yield and spike, grain number, grain weight were greater than 0.8, and effectiveness of the model parameters were greater than 0.7.2. Wet years, normal years and dry years Limits values were: 240 mm, 200 mm, 170 mm. The statistics in 30 years, wet years were 7 years, normal year were 16 years, 7 years of drought.3. The different precipitation years in inter-annual variation of precipitation: natural rainfall was alternating wet and dry, from 1986 to 1996 continuous dry season, from 1997 to 2003 continuous wet period, from 2004 to 2010 continuous dry season. The annual rainfall, wheat growing period precipitation of dry years, normal years and Wet years showed increasing trend.4. The variation of different precipitation years in precipitation distributed: at dry year precipitation of wheat growth period from the seedling stage to jointing stage increased; at normal year precipitation of wheat growth period from the seedling stage to heading stage increased; at wet year precipitation of wheat growth period from the seedling stage to jointing stage increased.5. The mechanism of different precipitation in annual precipitation for wheat yield: annual precipitation and growth of precipitation in dry years, normal years, wet years were positive effect on wheat yield,annual precipitation thresholds were 345.36,411.85,476.9mm; growth of precipitation in normal years and wet years thresholds were 227.36、277.72 mm.6. The mechanism of different precipitation years in the distribution of precipitation on wheat yield: the maximum impact was filling stage, least impact was jointing stage in dry years; the maximum impact was heading stage, least impact was young flowering stage in normal years; the maximum impact was maturity stage, least impact was young filling stage in wet years, and seedling stage, maturity and yield of wheat were significantly associated.7. The mechanism of different precipitation years in wheat yield components on wheat yield:The largest direct action and positive effect of grain number on wheat yield in dry years, normal years, the largest positive effect of grain weight on wheat yield in wet year.