Design And Implementation Of Precision Fertilization Information System For Mountain Tobacco Based On Mobile PDA

Tobacco is one of the most important economic crops in our country,and it is emphasized that high quality and suitable production.The key to achieve the goal of high quality and high yield is the scientific fertilization management.Panzhihua,as the production base of high quality tobacco in Sichuan Province,has a high average elevation of 1750m in the main tobacco producing area and complex landform types.The factors affecting the amount of fertilizer on tobacco are variable which requires a high demand for tobacco’s formula fertilization.In recent years,the mobile GIS technology based on PDA is developing rapidly,and it has been widely used in many industries and it also shows the potential and advantages in agricultural production.Based on the analysis of the development status of fertilization information system and its application platform at home and abroad,Dalongtan Town,a typical tobacco growing areas in Panzhihua,was chosen as the study area in this paper.At first,the key technologies of system development was discussed.Then with the GIS technology,the mountain tobacco ecological environment database based on the tobacco field was founded.Tobacco fertilization comprehensive model was established according to experts’ decision making knowledge,fertilization field survey data and the theory of human-computer interaction.The coupling of ecological environment database and fertilization model was realized,and each function was programmed to implement based on C#.NET for ArcGIS Engine.Finally,system running on mobile PDA and GPS positioning function were both implemented,the precision fertilization information system for mountain tobacco based on mobile PDA was obtained and verified in production.The main results are as follows:(1)GIS technology was applied to found the mountain tobacco ecological environment database that contains administrative divisions,fertilization management units,water systems,tobacco infrastructure and other elements.The E-R model was used to design the 10 physical objects,including administrative divisions,soil types,soil texture,soil samples data,field types,terrains and landforms,and so on.Tobacco fields were extracted by vector in high-resolution remote sensing images.A total of 5782 of tobacco fields of Dalongtan Town was obtained.Taking the fields as the fertilization management units,the GIS method was used to obtain more than 16 items of information about the ownerships,soil types,field types,soil nutrient contents and so on.The accuracy of fertilization decision was ensured by making basic fertilization information specific to each tobacco field.(2)A comprehensive tobacco precise fertilization model was studied and established.Fertilization experiment and verification test data for many years were used to establish the basic tobacco fertilization model which founded on improved fertilizer response function.The amendment rules of fertilization on 10 kinds of model parameters,such as soil factors,preceding crops and organic fertilizer were studied.To ensure the scientific of the fertilization model and to make it more suitable for production practice of tobacco,the basic fertilization model was optimized by using the theory of human-computer interaction.(3)By using C/S three layer structure model and the concept of embedded development,the overall design of the system was completed.The system was divided into presentation layer,application service layer and data service layer.Based on the visual development environment of.NET Framework,ArcGIS Engine embedded GIS platform and C#programming language were applied to realize the coupling based on vector data of fertilization model and geographic spatial database.Five functional modules including map operation,map query,GPS positioning,fertilization management and production management were realized by programming.(4)Mobile GIS technology was utilized to obtain the precision fertilization information system for mountain tobacco based on mobile PDA.GPS signal was received and converted through the simulation of serial communication port based on the GPS receiving module with embedded mobile terminal PDA,and then the coordinate system of GPS signal was converted by programming.The realization of various functions of GIS was extended to a more flexible outdoor environment.The system realized the portability of application of fertilization management technology of tobacco,so that the majority of tobacco workers guide fertilization can be more conveniently and efficiently.(5)The recommended fertilization results of the system were proved to be reliable.A verification test was carried out on Yunyan series planting on the sloping land.Compared with conventional fertilization scheme,the fertilization amount by system guiding reduced by 12～18 kg/667m2,and the tobacco leaves performances of each growing were better.After roasting,the nicotine content in the upper,middle and lower parts of tobacco leaves decreased by 16.23%,15.85%,and 17.50%,the total sugar content increased by 23.31%,14.99%,and 6.03%in the appropriate range,and the chemical qualities were more coordination.The tobacco yield increased by 15.62 kg/667m2,and output value increased by 816.30 yuan/667 m2,the proportion of middle and upper tobacco increased by 10.76%,which has realized the efficient use of fertilizer and achieved good economic and environmental benefits.