Study of Rice Fertilization Based on GIS and Evaluation of Agricultural Geo-environment in Yugan County
|School||Jiangxi Agricultural University,|
|Course||Crop Cultivation and Farming System|
|Keywords||Environment quality Rice Suitability evaluation "3S" Technology Fertilization model Expert Decision System|
Agriculture is a foundation of the national economy; farm production is the first productivity of eco-system. The environment is the basic condition which farm production depends on. The conditions affect directly the quality of the farm produce. In recent years, because of the pollution, such as waste water\waste gas waste residue from the factory and mining area, urban sanitary sewage and agricultural non-point source pollution, the environment of producing area has been polluted and destroyed seriously. Producing environmental pollution was an important factor to constraint sustainable development of agriculture and rural economic. So it is very important to evaluate the environmental quality in the rice producing area for developing the uncontaminated rice produce property and to study the practical protection measures. In this paper, it is the first time to investigate the environment quality in the rice main production region According to "soil environmental quality standards","Surface Water Quality Standards"," eco-environmental quality evaluation technology and methods "and" Chinese soil survey technology ", the comprehensive pollution index model was used to quantitative evaluate the environment quality. Combined with suitability evaluation result of rice, the rice producing area is divided three zones. Based on "3414" test data, soil nutrient adjustment coefficient model is constructed and regionalized fertilization model of rice is established by GIS. In conclusion, the organic integrated research and development of expert decision system for soil testing and fertilizer recommendation is formed based on WebGIS and fertilizer recommendation model.1、According to agriculture geological materials, remote sensing image data and soil materials, a comprehensive evaluation of environmental quality is carried in rice production area. The results show that:the geological environment quality overall is good, and there are very few places which the soil and water is polluted. High-quality agricultural areas are mainly distributed in the Lake District and valley plains, soil nutrients are abundant, and there is without pollution in soil and water. Area of middle-quality is the largest with percent accounting to84.94%, it is distributed in all the region, soil nutrients are rich, and soil and surface water quality is non-pollution or light pollution. Low-quality agricultural areas mainly are distributed in Shengeng、Jiulong and Jiangbu township, and there are lack of soil nutrients. The ecological environment quality overall is good in Yugan county, vegetation cover is high, biodiversity is rich, eco-system is stability, it is more suitable for human. Soil OM and available N is rich in generally, there are lack in Lushigang Township. Available phosphorus overall is moderate and is low in Hongjiezhui Township. Available potassium overall is moderate, the rich area concentrate on Ruihong Township and the low area concentrated on Meigang Township.2、Fourteen factors is selected from the site conditions, profile configuration, topsoil conditions, barriers and soil management, fuzzy comprehensive evaluation model is used to evaluate rice suitability in the paddy fields. Combined with environmental research, the paddy fields are divided into three districts, such as high-yield district, moderate-yield district and low-yield district. The results show that: Rice suitability is high in generally, the largest is grade one, it is advantage region and is very suitable for rice growing which conditions are the best. Grade two is second, it provides a good condition and is suitable for rice growing. The smallest is grade three, there is important factor to limit rice growing, so it is need to take appropriate improvement measures. The high-yield is23893.50hm2, counting for37.35%of the total paddy fields, the conditions including natural environment、infrastructure、 geological environment and ecological environment are excellent, and suitable for high-quality rice. The moderate-yield is the largest which is33887.22hm2, conditions are good and suitable for rice growing, and it is important region for rice production. Low-yield is the smallest, counting for9.68%of the total paddy field, conditions is generally and agricultural infrastructure is poor, barely suitable for rice growing, so it is need to strengthen water conservancy construction for improving the suitability of rice.3、Union soil testing and fertilizer datum, this research analyzes soil nutrient distribution condition, based on rice zone, obtains the paddy soil fertility comprehensive district, synthesizes GIS and the modeling technology to get paddy fertilization program in all areas of the district. The findings indicate: The soil nutrient at Yugan County can be colligating zoned seventeen districts, the largest district is II-IV which is20314.18hm2, counting for31.75%of the total paddy fields. The second is I-IV with area of8285.26hm2, counting for12.95%of the total paddy field. The smallest is Ⅲ-Ⅱ, which is only209.98hm2, counting for only0.33%of the total paddy fields. Based on "3414" data, soil nutrient adjustment coefficient model is constructed which is Winpu(?)=WoutpUt×(G/100)×Tn, it overcome fertilization model defects of the traditional target yield method, fertilization recommendation is in line with the actual situation of Yugan County, so it can be promoted to guide scientific fertilization for farmers.4、Take C#as the development language, using ASP.net and Silverlight, basing on building a fertilization model, the research build the Expert Decision System for Soil Testing and Fertilizer Recommendation base on WebGIS. The results show that:The system uses visual development languages C#and Silverlight technology, not only with the function of GIS data and space analysis like traditional, but also with the specially of function of data sharing, which provides a benign platform for the information of soil test for formulated fertilization publishing and sharing. The functions of Expert Decision System for Soil Testing and Fertilizer is divided into map displaying, fertilizer recommend, administrator management and other relevant modules, every module can be divided into several functions. The system can take the best of fertile business management needs for the agricultural sector, and achieve requests at convenient providing scientific fertilizer guidance for farmers.