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Design And Realization Of Integrated Management Expert System For Drip Irrigation For Cotton In Arid Area

Posted on:2018-09-14Degree:MasterType:Thesis
Country:ChinaCandidate:L WangFull Text:PDF
GTID:2348330533964496Subject:Crop Cultivation and Farming System
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In recent years,with the development of science and technology,information technology has been widely used,and its application in the field of agriculture has led to a new technological revolution.As one of the branches of agricultural information technology,the role of intelligent agricultural information technology,which is represented by expert systerm,is particularly prominent.Xinjiang,as China's largest cotton plantation,due to the low level of production management,cotton production and quality potential has not been developed,It is very important to establish the expert system for integrated management of drip irrigation for cotton in arid area,which is of great significance to solve the problem of low efficiency of water,fertilizer and medicine in cotton cultivation management,and to realize the dynamic regulation of cotton growth process and the consulting services about cultivation technology.In this study,29 varieties which are widely planted in Xinjiang and 3 nitrogen?second year?were designed.The data of cotton growth period,plant height,leaf age,buding number and so on were investigated regularly,through the data analysis,building various types of models,and model validation,based on the cotton cultivation and management measures in Xinjiang,an expert system for integrated management of drip irrigation for cotton in arid zone was established.The main results were as follows:1.A dynamic model of cotton plant height was constructedThe relationship between relative GDD and relative plant height of different cotton varieties was studied by using normalization and cluster analysis.The results showed that the relative height of the cotton plant changed consistently with relative GDD in spite of different variety.Here we established three categories of simulation model about plant height based on relative GDD:y= a/?1+exp?b-cx??1/d.Among these,the class I?from 3-leaf stage?relative plant height value is less than 0.14?to 11-leaf stage?relative plant height value is less than 0.7?,the growth rate of plant height is slow?:y = 0.997/?1 + exp?26.08-33.62x??1/8.66?r=0.9976?;The class ??from 3-leaf stage?relative plant height value between 0.14-0.18?to 11-leaf stage?relative plant height value between 0.7 to 0.8?,the growth rate of plant height is fast?:y = 0.997/?1 + exp?22.09-28.65x??1/8.41?r=0.9967?.The class III?from 3-leaf stage?relative plant height values greater than 0.18?to 11-leaf stage?relative plant height greater than 0.8?,the growth rate of plant height is superbly fast?:y = 1.02/?1 + exp?8.55-12.68x??1/3.25?r=0.9973?.The verification of the model shows that the value of RMSE was 1.6998cm,indicating that the error between simulated and observed values was relatively small.Therefore,Richards function can effectively predict the changes of plant height in cotton.2.A dynamic model on leaf age in cotton was constructedThe relationship between relative GDD and leaf age of main stem of different cotton varieties was studied by using physiological developmental factor,normalization and cluster analysis.Based on the 8 leaf age,the developmental process of leaf age was divided into different stages.Respectively established dynamic model of cotton leaf 1-8 based on national function and dynamic model of cotton leaf 8-13 based on two times polynomial and rational function,determination coefficients were 0.9719,0.9964,0.9743,0.9733.The results of model test showed that the simulated value and observed value of leaf age of different varieties were RMSE = 0.3505,R2 were 0.9977,indicating that the error between the simulated and observed values was relatively small.Therefore,Rational functions and quadratic polynomials could effectively predict the changes of leaf age 1-8 and leaf age 8-13 in cotton,the model could be used for precision management of cotton by observing the growth condition of cotton leaf age.3.Establishment of expert system for integrated management of drip irrigation for cotton in arid areaBased on the cotton cultivation management measures and the expert knowledge in the field,combined with the model established in this research and other cotton simulation models established by others,the expert system for integrated management of drip irrigation for cotton in arid area was established,including six parts:database,knowledge base,model library,inference engine,knowledge acquisition and man-machine interface,The system realized the five functions,such as:data management and system maintenance,expert consultation,planting scheme design,model simulation and prediction,real-time control and so on.According to the user's input decision-making location of the climate environment,soil and other basic data,the system help users to design a reasonable cultivation management program.
Keywords/Search Tags:Arid area, Drip irrigation cotton, Plant height model, Leaf age model, Expert system
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