Model Research Of Meathane Emission From Ploder Rice Paddy By Field Trials

Chao lake polder rice cropping systems represented by field test monitoring results on CH₄ MOD, DNDC model optimization, improvement and selection, try to establish a suitable low-lying polder Yangtze River typical of methane emission models.Field experimental design blank（CK）, General（CG）, conservation tillage（BG）, straw（CS） four treatments, using static chamber- gas chromatography routine monitoring plots to study fertilization and tillage on the impact of CH₄ emissions.The results showed that:（1） The measured data show, CK compared with CG, CH₄ emissions decreased by a total of 4.85 percent, rice production fell 21.48%; BG compared with CG, CH₄ emissions decreased by 7.88%, rice yield increased by 1.48%; CS compared with CG, CH₄ emissions rise 47.06%, rice yield is essentially the same. In addition to the control of conventional non-significant difference, the rest are there are significant differences between the four farming methods;（2） DNDC model simulated CK, CG, BG, CS four treatments of the total CH₄ emissions magnitude of the error was 12.36%, 3.37%, 4.16%, 3.68%, on the whole can better simulate the basic treatments Rice season total methane emissions.（3）The sensitivity of the DNDC model analysis shows that temperature, soil organic matter, soil texture is the important factors influencing the paddy CH₄ emissions. Paddy CH₄ emissions and air temperature, soil organic matter content is positive correlation, negative correlation with soil clay proportion; Emissions of methane daily correlation between simulated and measured values were 0.29, 0.359,0.283,0.107, to better simulate the Methane Emission CG processing for CK, BG, CS and other laws deal with emissions of CH₄ analog, not obvious, which simulate the effect of CS on the Law of the worst treatment discharge;Sensitivity analysis（3） DNDC models show temperatures, soil organic matter, soil texture are important factors affecting the CH₄ emissions. CH₄ emissions from rice paddies and the air temperature, soil organic matter content positively correlated,negatively correlated with soil clay content;（4） CH₄ MOD model to simulate the CK, CG, BG, size of the error total methane emissions CS four treatments were 46.37%, 42.98%, 37.72%, 12.75%, compared with analog value found four treatments were small, and CK, error handling CG and BG are three large, CS treatment closer. Emissions of methane daily correlation between simulatedand measured values were 0.701,0.550,0.544,0.464 for CH₄ emission from the simulation is better, we can simulate the basic emissions law;（5） CH₄ MOD model sensitivity analysis showed that the total methane emissions and air temperature, soil sand content, rice coefficient proportional; inversely proportional to the intrinsic rate of increase in the growth of rice, rice initial aboveground biomass;（6） CH₄ MOD model as a framework, by adding soil organic matter decomposition,were precipitation amendments Eh adjust methane in methane emission model transmission distribution ratio of each path, obtained its analog out of the total methane emissions for each process the amount of the measured value is close, and the correlation coefficient between simulated and measured values are extremely significant, to better simulate the lake polder methane emission laws.