Studies On Soil Carbon And Nitrogen Dynamics Under Long-term Fertilizer In The Black Soil Based On DSSAT-CENTURY Model

The black soil region of northeast is an important food industry base in China, in recent years with the unreasonable fertilization led to increasingly degraded black soil,not only caused a serious impact on food production, but also a threat to the ecological environment. Therefore the use of DSSAT-CENTURY soil model, the research different long-term fertilization measures on the changes of soil carbon and nitrogen cycling, and different long-term tillage on soil carbon and nitrogen leaching effect, not only helps to use model system for evaluating and forecasting soil timelness, provides the theory support for evaluating and forecasting soil timeliness, provides the theory support for the regional development model, but also help to realize the sustainable development of agriculture.In this study, long-term experiment Gongzhuling base for the study, by the four fertilizer treatments(1) CK: no fertilizer(2) NPK: nitrogen fertilizer P and K(3) MNPK: manure and NPK fertilizer(4) 1.5MNPK: 1.5 times the organic manure and NPK fertilizers, soil use DSSAT-CENTURY model to explore dynamic changes of the long-term application of organic fertilizer on maize yield conditions, soil organic carbon, total nitrogen, soil C /N of and by simulating different levels proportional change in carbon stocks, and the distribution of different inorganic nitrogen balance topsoil nitrate and ammonium nitrogen content, the following conclusions: Compared to NPK, the long-term application of organic fertilizer could significantly increase crop yield, was significantly affected by the drought years less precipitation effect. Effect of organic manure on soil organic carbon and total nitrogen content of the larger, soil SOC content from high to low is 1.5MNPK>MNPK>NPK, soil total nitrogen and organic carbon change tendency is consistent. Risk of organic fertilizer and inorganic fertilizer can significantly reduce the content of inorganic nitrogen on the soil and reduce the loss of nitrogen. The ratio of C/N through the simulation model that can also explain: the application of organic fertilizer increase C/N showed that soil organic carbon increased faster than organic nitrogen, and the changes of soil changes in chronic SOM2 library determines the content of soil organic carbon. Total organic carbon pool affected by chronic carbon pool is more significant, and inert carbon pool changes most significantly, while under CK inert carbon sink ration increased significantly soil in aging. More precipitation year soil nitrogen leaching amount showed a significant increasing trend, explain the precipitation caused soil nitrate nitrogen leaching into deep soil, through the application of organic manure makes the total mineralization of soil inorganic nitrogen increased significantly, which indicated that the soil mineralization at the higher level. The nitrate nitrogen content in the different topsoil is different, and different fertilization measures cause leaching of nitrate nitrogen in different peak, the applying of organic manure significantly moving peak to the root zone, reduce the risk of leaching. Changes of ammonium nitrogen content of each soil basic consistent,0-60 cm changed significantly, profound changes of soil nitrate nitrogen was changed. Therefore in the nitrogen input at the same time should pay attention to organic manure carbon return level, therefore vigorously promote the use of farmyard manure to improve soil nutrient content, integrated to realize sustainable development of agricultural ecological environment.