| The study of agro climatic potential productivity and its corresponding demands for nutrients is always a focus that is very important to make sure of the climatic resource status and to direct the agriculture product in an area. Many scientists have made a great deal of studies to explore the problem of the potential productivity. But those studies emphasize particularly on the statistical models or the static mechanism model. Because of the inherent limitations of those models, the results of these models are not ideal. So scientists begin to adopt the theory and methods of crop grow simulation in the research of potential productivity and its corresponding demands for nutrients. The crop grow simulation model excels the other models in the properties of dynamic and mechanism.This paper discusses the weather potential production and its demands for nutrients of Chongqing primarily with the methods of crop growth simulation. Until now in Chongqing no reports on those jobs have been presented. The aim of this paper lies in:Based on existing growth simulation models, with the methods of crop growth simulation, build the weather potential productivity and its corresponding nutrient demands simulation model of rice. And apply it to discussing the agro climatic productivity and its corresponding demands for nutrients in ChongqingThe significations of this paper lie in:1. Study the agro climatic productivity with the new methods of growth simulation and the model built in this paper has the characterizations of mechanism and dynamic. It is important to the studies of potential productivity and land carrying capacity of Chongqing.2. Be important to the accurate agriculture. The model developed in this paper could be used to simulate the growth of the rice and its corresponding demand for nutrient (nitrogen). So the result of this paper can act as the basis of accurate agriculture in Chongqing.3. At the present, the industry fertilizer is used heavily. As a result, the eutrophication in water system occurs. Furthermore, the fertilizers are transformed into the forms of N2O, NO and NH3, and those greenhouse gases are given off into air. Through the study of this paper, the demands for nutrient (nitrogen) by rice can be simulated, providing references and foundation for fertilizing in fields.After a great deal of experiences in the fields and the simulation jobs in room, the agro climatic potential productivity and its demands for nutrient (nitrogen) are simulated. The main results include:1.The numerical simulation model of agro climatic potential productivity and its corresponding demands for nutrient (nitrogen) are developed.Based on the studies of Gaoliangzhi, De Wit and H Van Keulen, build up the numerical simulation model of agro climatic potential productivity and its correspond ing demands for nutrient (nitrogen). Through the experiments inBeiBei, the parameters of the model are modified; the model is tested with the datum obtained from the field experiments; and the sensitivity of the correlated parameters to the model are analyzed to make sure of how the model are effected by the parameters. The result proves that the model can simulate the accumulation processes of dry matters and nutrient (nitrogen) of the rice exactly.The model is tested with the datum of the field test and the weather datum of 2002. The result proves that the model can simulate the accumulation processes of dry matters and nutrient (nitrogen) of the rice exactly. The regression of the equation y = ax + b(y means the simulated value; x means the experimental value) is remarkable, which proves that the trends of the simulated values and the tested values are similar. The difference between the equations y = ax + b and y = x is not remarkable, which proves that the amounts of the simulated values are consistent with the tested values. For the sensitivity analysis of the parameters, the sensitivities of the parameter P (in the model for growth) in the period before tassel, after tassel and the whole growth period a...
|
PDF Full Text Request