Simulating Carbon And Nitrogen Cycle In Soil-Plant Under Maize-Soybean Crop Rotation In Black Soil Zones

This study is based on the long-term experiment Gongzhuling nearly 20 years(1990-2008)of meteorological data, soil data, crop varieties and years of data corn- soybean rotation field trial data, and use them as input files DSSAT Model by commissioning model in corn and soybean varieties genetic parameters to determine the genetic parameters after simulation 1990--2008 years, leaf area index, harvest index, aboveground total weight of the soil organic carbon pool, plant nitrogen content, crop nitrogen total absorption and soil inorganic nitrogen and nitrogen leaching, in order to verify the model application results DSSAT Northeastern Black Earth region, provide theoretical support for the results of field trials to achieve rational fertilization, improve crop yields and protect the ecological environment has important theoretical significance and value for the protection of our sustainable economic development in Northeastern Black Earth region and other relevant.We are finding that :(1) DSSAT model can well simulate the change trend of corn- soybeans kernels after heavy, can predict the development trend of kernels weight, can be used to evaluate the actual kernel weight of corn.(2) the corn- soybeans under simulation trend of leaf area index and harvest index, are a trend of gradually slow down after rising first, and quickly become flat after increased to a maximum. Photosynthate all corn and soybean crop rotation crop organs to grain, and improve the crop yields.(3) the corn- soil organic carbon pool and soil under the soybean crop rotation inertia simulation curve of carbon library basic same, all showed a trend of declining, inert soil carbon content is almost accounts for over 97% of the total soil organic carbon, and can use the change of soil carbon inert to predict the change of soil organic carbon content direction. Soil carbon residue fluctuation change accords with the development law of soil carbon library. Reserves change trend of soil organic matter is consistent, smaller differences in different growth period of soil organic matter reserves after seeding time, began to increase soil organic matter reserves.(4) the corn- soybeans under the simulated curve of plant nitrogen content are not consistent, inorganic nitrogen and nitrate nitrogen content of curve is relatively close, crop nitrogen content in grains is increased rapidly to a level gradually, extreme value after stem +leaf nitrogen content after the first rise; After the aboveground nitrogen content increased first,then smooth rise gradually slow growth. The morphology of soil nitrogen leaching, mainly for nitrate leaching of soil nitrogen with rainfall is inseparable, simulated rainfall fluctuation curve and the total soil nitrogen leaching is consistent, but rainfall and nitrate leaching is not a linear relationship.