Evaluation Of Cultivated Land Fertility Based On GIS Of Luan City

Arable land and human lives are closely related and moreover the output and quantity of grain as well as the sustainability of agricultural production are directly determined by the fertility of the farming land.Lu’an’s reserve arable land is relatively scarce and the infrastructure is comparatively weak.Besides,economic development,population growth and the loss of arable land,especially arable land,intensified the contradiction between land supply and demand.In order to improve the management of land resources,especially arable land resources,and ease the contradiction between people and demand of land,more reasonable and scientific fertilization and cultivated land fertility evaluation is imperative.In this study,the research area is confined to Lu’an City,using GIS technology and County Land Resource Management Information System software(CLRMIS)and SQL analysis as platform.Besides,using soil testing data as basic data,and superimposed Lu’an administrative map,soil map and land use map by GIS software,ArcGIS ordinary Kriging,graph overlay method and "point to surface"are all used,combining assignment unit of arable land resource management unit forming the greatest degree of assurance of the accuracy of the data evaluation.Selecting index using the Delphi method,AHP to determine the weight of evaluation factors,the calculation method of soil fertility index accumulated by cumulative frequency curve combined with the local division of cultivated land fertility actual rating.the farmland productivity evaluation of Lu’an city has carried out.According to the standard classification of soil nutrients in the second soil census,the Lu’an organic contents are generally low,the proportion of the middle and scarcity of arable land were respectively 37.85%,54.14%.The Lu’an city organic contents in soil type and land use type are medium level or slightly lower,skeletal soil,black limestone soil,purple soil and paddy fields organic matter relative to other types is high.90%of all nitrogen are in the middle and relatively abundant levels,all nitrogen in the yellow cinnamon soil,black limestone soil,skeletal soil and paddy fields relative to other types is high.K content is generally low,the proportion of the middle,the lack of arable land in the levels of the total area of farmland were respectively 36.08%,60.23%,K contents in soil type and land use type are in lack levels,Shajiang black soil,yellow cinnamon soil and irrigable land is high than others.Cultivated soil available phosphorus content 84%in the middle and relatively abundant levels,Shajiang black soil,Shajiang black soil,Fluvo-aquic soils,paddy soil and irrigable land phosphorus content is relatively high.In Lu’an City,total nitrogen,phosphorus,potassium coefficients of variation were respectively 0.33,0.41,0.57,0.46,belonging to moderate variability.Variability of soil nutrient phosphorus>K>total N>organic matter.Lu’an farmland productivity evaluation method using the calculated cumulative index of soil fertility and the local conditions of soil fertility in grade by dividing the Lu’an cultivated land fertility classification into five levels:First,Lu’an area of 56,115.4 ha,accounting for 8%of arable land,mainly in Huoqiu County,Jin An District,Yuan District.Various evaluation indicators are relatively good and it is the best soil in Lu’an distribution;second area of 164,977.1 hectares,accounting for 25%of the cultivated area,mainly in Huoqiu County,Shou,Jin,including relatively flat terrain,deep soil,good irrigation and drainage conditions,nutrient medium level;third-class area of 230,803.3,accounting for 34%of arable land,mainly in Huoqiu County,Shou county,Yuan District,Jin’an district including surface texture,moderate,good tilth,soil nutrient content and moderate,but is lack of potassium content,poor irrigation;four other places area 159,235.6,accounting for 24%of arable land,mainly in Shou County,Shucheng county,Yuan district,Huoqiu County,there are obstacles level,and irrigation and drainage conditions are good,some are mild erosion,drought-prone flood,while shallow topsoil low production levels;five other places area 63,115.6 hectares,accounting for 9%of arable land,mainly in Shucheng County,Huoshan county with poor drainage,low soil nutrient content,and water conservancy facilities are backward,poor irrigation drought-prone,arable poor.Using GIS technology to survey and evaluation of farmland productivity in Lu’an city,relative to the traditional methods,saving time,effort,precise and efficient,also sped up the results of the farmland productivity evaluation to application in agricultural production.The results will serving the farmers and provide decision support to managing land and to guide agricultural production,at the same time to provide technical support and guidance for farmers scientific fertilization,it will better guide the reasonable and efficient utilization of the cultivated land,efficiency of agriculture and increasing farmers’ income.