Study On Model And Gis-Based Prescription Generation Technology For Precise Management In Rice

The precision crop management model is the digital base of making variable prescription, and is the core of precision farming information management. The technology of precise management prescription generation bases on different variety types, ecological environments and production levels, it needs to give full play to the advantage of the precision crop management model and combine with spatial information acquisition and analysis techniques. And now, it has become the urgent need to address the important technology to develop precision farming at home and abroad. Also, it is an inevitable trend of development of digital agriculture. This research is based on rice. By summarizing, inducting and extracting the dynamic relationships between growth characteristics, rice cultivation technologies, planting method, farming system, variety type and ecological conditions, a knowledge model for rice was optimized through knowledge engineering and system analysis methods. On this basis, by combining with model and GIS, using the principles of geostatistics and GIS, a technology system on precise management prescription generation in rice was developed, which is based on soil information, meteorological data analysis of the spatial difference at different scales. The achievement of this research indicates a better performance of the model system in accuracy, decision-making and wide applicability, this work laid a theoretical foundation for the optimization of other crops, and has provided a basic platform for future research.Based on the time-course relationships of crop-environment-technology, using the system analysis method and mathematical modeling technique, considering the effect of different planting method(hand transplanting, machine transplanting, throwing transplanting, direct seeding), different farming system(single cropping, double cropping) and weather conditions, varieties types, soil conditions, ratio of straw returning, target grain yield, fertilizer and water conditions, cultivation management level, the knowledge model for rice was improved. This research has proposed the algorithm of transplanting date for the first time, and has described the algorithm of suitable sowing base on the best heeding date and leaf number on main stem, the model can make rice be transplanted in time and heeding at the best heeding date; Model for designing suitable population density in rice may design suitable population density under different planting mothed; Considering effect of planting method, soil fertilities, cultivars type and ratio of straw returning, model for designing rations of basal to dressing nitrogen was developed; Model for designing suitable tiller dynamic and dry matter accumulation dynamic were developed with normalized effective accumulated temperature and the population growing index, tiller dynamic described by Raditional Function, dry matter accumulation dnamic described by Logitic curve. Case studies on the new model indicate a better performance of the model system in accuracy, decision-making and wide applicability.On the basis of the precision rice management model, a model and GIS-based decision system for precision farming was established by using the techniques of object-oriented and component-based programming and incorporating the GIS. By combining with the knowledge model for rice management, spatial analysis technology for different regional scale base on geostatistics and management zone technology, a technology system for precise and quantitative management prescription generation in rice base on model and GIS was developed. The difference reflected in management unit and controlling factor of difference between management unit. This work laid a theoretical foundation for the precision management of other crops, and has provided a basic platform for more large regional scale research.Case studies with the demonstration experiment data sets of comparative fields of different eco-sites(Wujiang, Kunshan, Wuzhong, Jintan, Xinchang, Wujin, Danyang, Xianju) in2008-2010indicate a good performance of the technology system. In different scales, compared with the control management prescription (convention management prescription and farmer management prescription), the precise management prescription which is generated by the technology system requires less input and gets higher yield,.Population growth dynamics of rice growth period is more reasonable, Spike grain number and1000-grain weight of yield components have more advantages, and the yield were increased by5.45%～26.35%, total fertilizer-N application rate were saved by7.5～13.5kg·hm-2, total economic benefit were increased by1026.2～2435.6yuan·hm-2. And this technology system developed by the authors created more and environmental benefits.