Development And Application Of Expert System For Paddy Fertilization Of Ningbo Based On GIS

With increasing in the amount of fertilizer, crop fertilization yield has dropped. The phenomenon of irrational or blind fertilization on the environment had a tremendous impact. Therefore, reasonable application of fertilizers has become essential according to local conditions. Geographic Information System (GIS) is to study the intersection of computer science with the emerging disciplines, applying to agriculture in order to solve the actual decision-making, technology promotion, production forecast, fertilizer recommendation and other issues of modern agricultural development. This paper attempts to combine GIS and AI(artificial intelligence) in order to construct expert system for paddy fertilization of Ningbo, including functions of agricultural fertility integrated query, thematic map production and fertilizer recommendation. The establishment of the system could provide decision support for the practice of precision agriculture and promote the development of efficient ecological agriculture. This has important practical significance. The main results are as follows:(1) This paper studied the effects of different fertilizer models on simulation for the'3414'fertilizer experiments, which were conducted from 2007 to 2010 in Ningbo of Zhejiang province ,China. With the analysis for data, the index system of soil nutrient(Total nitrogen,Olsen-P and Available K) abundance on Ningbo paddy rice were established. The results indicated that, the regression equation index for soil total nitrogen content in riverine plain areas and coastal plain areas are y=31.295Ln(x)+51.98 (r²= 0.8804) and y=23.499Ln(x)+68.696(r²=0.8676),respectively; the regression equation index for soil Olsen-P content in riverine plain areas and coastal plain areas are y=31.139Ln(x)-24.54 (r²=0.8212) and y=29.467Ln(x)-7.088(r²=0.9091) , respectively; the regression equation index for soil available potassium content in riverine plain areas and coastal plain areas are y=39.464Ln(x) -94.875(r²=0.8159) and y=42.543Ln(x)-118.90 (r²=0.8791). According to regression equations, the index system of soil nutrient (total nitrogen, Olsen-P and available K) abundance can be divided into high, medium and low three-level. Corresponding critical indicators of total nitrogen, Olsen-P and available potassium are 4.0 g/kg,47 mg/kg,122 mg/kg respectively in riverine plain areas, 3.1g/kg,32mg/kg,150 mg/kg respectively in coastal plain areas, which showed critical indicators of total nitrogen, Olsen-P in riverine plain areas were greater than that in coastal plain.(2) This paper concerned about the current main cultivated varieties of rice in NingBo,which establish the index tree of the nutrient (N-P-K) levels in the soil. The fertilizer recommendation of total N,total P and total K in riverine plain areas, for single cropping rice: N 11-13,13.5-14.5,14.5-16kg/667m², P₂O₅ 2.5-3,3-3.5,4-5 kg/667m², K₂O 7-8.5,8.5-10.5,10.5-11.5 kg/667m² ; for early rice:N 10.5-11,12-13,14-15kg/667m², P₂O₅ 3-3.5,3.5-4.5,4.5-5 kg/667m², K₂O 2.5-3,3-5,5-6 kg/667m²; for double cropping late rice: N 11-12,13-14,15-16 kg/667m²,P₂O₅ 2.5-3,3-3.5,3.5-4 kg/667m², K₂O 3.5-4,4.5-5,5.5-6 kg/667m². The fertilizer recommendation of total N , total P and total K in coastal plain area for single cropping rice, N 12-13, 14-16, 17-17.5 kg/667m², P₂O₅ 3.5-4,4-5,5-6 kg/667m², K₂O 2.5-3.5,3.5-6,6-7 kg/667m².(3) In this paper,GIS and Expert system has been combined by the establishment of the database and spatial database, in accordance with the establishment of nutrient sufficiency indices of paddy Soil in Ningbo by using a large number of experimental data. The secondary platform of"ArcGIS Engine", developed by ESRI was adopted. The final completion was expert system for paddy fertilization of Ningbo based on GIS. System includes, ,soil nutrients and four-module, in order to provide application and print functions of distribution and accurate formula. System was used friendly and easy to be understanded. It was practical, easy and convenient for the farmers with the guidance of scientific fertilization, for grass-roots promotion of agricultural sector to provide technical support ,for the agricultural fertilizer business networks to provide application platform, for government decision-making to provide a reference.