Study On The Variation Characteristics Of Space-time Suburban Soil Quality In Shanghai

Hangzhou bay region soil ecosystem was important influence by rapidurbanization. On this paper, we considered human activities-soil property-plantgrowth-human health as a system, seemed the change of soil fertility quality in theprocess of rapid urbanization as the center. To reveal urban spatial distributionproperties and its inlfuencing factors of soil quality in the demo sample, sampleregion on the different scale. By Analysing the influence of urbanization and land usepattern on soil quality, exploring the process and mechanism of the interactionbetween them, because these have vital significance on maintain the stability of theregional ecological system and sustainable development。At the same time, combiningwith the second soil census data，we establish a basic database on soil of Shanghai,through the comparative and analysis of the change of soil quality during the past30years, to provide support of land using and scientific management for Shanghai andhangzhou bay area.In this paper, the main conclusions as follows:1、Soil quality performance as the following characteristics:Soil organic matter,electric conductivity, pH value, rapidly-available potassium basically stay at two,three and four levels; The soil total nitrogen, available phosphorus is given priority toland2levels. From spatial variation figure of each fertility index, we can find thattotal nitrogen, available phosphorus, pH showed city-outskirts-village gradient changetendency; we can also draw the conclusions that Shanghai’s soil fertility quality putup city-outskirts-village gradient belt from north to south, from city center to suburbgradually getting better, characteirzed the transition trend of “worst-bad-middle-good-best"; Most of the research area of soil integrated fertilityquality was” worst M and "bad". According to the requirements for new green space inShanghai the subsoil, soil conductivity rate of park and transportation green spacewere39.47%and23.3%respectively; all soil organic matter of traffic green spacewere unqualified; The qualified rate of organic matter of park green space was92.11%，basically meet the requirements. According to the requirement of the subsoilof agricultural land, about63.63%of Pu jiang farmland surface soil organic matterwere qualified，basically can offer the suitable soil for crop growth.2、Thedifferent functional areas of soil fertility quality had different spacemutation characteirstics, and different land use types had certain extent influenceonsoil fertility quality exists to a, urban ecological construction activities as parkmaintenance can improve soil fertility quality, residential construction and otherinfrastructure construction activities can reduce the soil fertility quality. Humanactivities such as land use ways can affect the value of soil organic matter, thecoefficient of variation of soil organic matter of agricultural land was highest, theaverage of soil organic matter content was also highest, management activities such asfertilizer in agricultural land can improve soil fetrility.3、Ifonly use function to evaluate soil quality city or sample belt scale for largescale soil quality, we maybe ignore other large scale soil sample measured smallernumerical; Research of soil fertility quality indexes and soil fertility quality levels indifferent scales, can not only play the role of complement each other, but also makethe study area is more comprehensive; The significance of multi-scale research forsoil quality of single factor is greater than comprehensive quality research.4、Inthe80s, the distribution of soil fetrility index was island shape combinedwith a ribbon, high value district and ifrst level of soil quality, basically located at thesoutheast of four group town, south of TuanQing highway, north of pudong lineextending from east to west, low value district is Xuhui, pH value, organic matter,available phosphorus was on the decline, total nitrogen, available potassium wereincreased，clay quality basically unchanged, but the space distribution features werenot change chearly，downtown were of poor quality, but there had a better trend of suburb soil. For30years，the Shanghai city-outskitrs-village belt transect soilcomprehensive fertility quality declined slightly, obvious influenced by theurbanization process and human activities.