Study On Expert Decision System Of Efficient Use Of Water And Nitrogen For Winter Wheat

The long-term water-nitrogen fixed position experiments, based on the winter wheat jing-dong 8, have been conducted on the Dongbeiwang Farm in the suburbs of Beijing in 2002-2004. The dissertation studied the effects of some higher-aim-yield water-nitrogen optimization models on the growth and development, yield and its components and water and nitrogen use of winter wheat. Based on these conclusions and some harvests have been obtained and much knowledge about wheat plant, the expert decision system of efficient use of water and nitrogen for winter wheat management has been accomplished, which could harmonize connection among yield and soil, climate , water , nitrogen. The main results are as follows:(1) The experimental results showed insignificant difference in winter wheat yield between the other three water-nitrogen optimization model and traditional water- nitrogen; slightly improved water use efficiency about all of the water-nitrogen optimization models; Insignificant difference in nitrogen use efficiency concerning the optimized irrigation-traditional fertilization, but significantly improved nitrogen use efficiency in regard to the other two water-nitrogen optimization models.(2) Some different growth-development characteristics and yield components of all the optimized treatments were found: (1)LAI on optimized-irrigation-traditional fertilization and optimized water-nitrogen was closed to traditional water-nitrogen, but traditional irrigation-optimized fertilization was insignificantly less; (2)Before heading , dry matter accumulation about all of the water-nitrogen optimization models was much less than traditional irrigation- traditional-fertilization, but after heading dry matter accumulation was much more than traditional water-nitrogen. (3)On return-cyan to shooting stage , booting to maturing stage, N%on traditional irrigation-optimized fertilization and optimized water-nitrogen was gradually falling; On shooting to booting stage N%was gradually falling increasing; But the extent of falling and increasing were all under the extent of falling and increasing on traditional water-nitrogen. (4)The yield components were insignificant difference between traditional irrigation-optimized fertilization , optimized irrigation-traditional fertilization and traditional irrigation-traditional fertilization; But on optimized water-nitrogen, tiller ear number was significant less and weight of 1000grain was significant more than traditional irrigation-traditional fertilization.(3) There were insignificant difference in quality and yield between the other three water-nitrogen optimization model and traditional irrigation-traditional fertilization-, But there was significant difference in economic benefits, the economic benefits on traditional irrigation-optimized fertilization was obviously more than all other irrigation-nitrogen models, by compare, traditional irrigation-optimized fertilization was the most effective irrigation-nitrogen model.(4) The dissertation analyzed characteristics of the data of precipitation, during different growth-and development terms of winter wheat in Beijing city in many years, studiedcorrective ratios of predicted values and predicted year types of precipitation by using neural network BP model. The results showed that the corrective ratios of predicted year types are greater.(5) According to analyses about characteristics of winter wheat plant and decision models of production control, the system was constructed with Visual Basic 6.0, ACESS was used for the back-end database, BP neural networks matlab, were also used in the developing process, a winter wheat production control efficient use of water and nitrogen expert decision system was established, which includes a series of data of crops, soil, water-nitrogen management measures and climatic factors ,and which realizes some functions such as decision about efficient use of water and nitrogen , dynamical forecast development indexess forecast and regulating of bearing-stage and query about general production contr...