The Yangtze delta area is among the fastest developing areas in China. Here there are mega-cities like Shanghai, Nanjing and the attached urban areas of different sizes including those along the lower reaches of the Y...The Yangtze delta area is among the fastest developing areas in China. Here there are mega-cities like Shanghai, Nanjing and the attached urban areas of different sizes including those along the lower reaches of the Yangtze River from Shanghai up to Nanjing as well as their satellite cities and towns, forming one of the most densely distributed urban areas in China. This is a case study done in Suzhou city at the center of the Yangtze delta to reflect the impact of urban sprawl on soil resources using satellite images and digital soil databases. The extent of the developed land in the studied area and the impact of development on soil resources at 1:100,000 scale are estimated and the soil types impacted most by urbanization development are determined through overlaying the soil map on the satellite images (Landsat-7) of the studied area at different times (1984, 1995, 2000 and 2003). The methodology for this study consists of analyzing data resulting from using a geographic information system (GIS) to combine urban land use maps of different times derived from satellite images with data on soil characteristics contained in the established soil databases by which some results come into being to present the fast expanding trend of urbanization in the Yangtze delta area, the urban spread and the soils occupied by the urbanization process, and also the quality of the occupied soils.展开更多
对江西省余江县28个典型田块的调查结果显示,余江县稻田土壤以粉砂壤土和壤土为主,土壤pH值在4.78～5.37之间,属酸性土壤。参照第二次全国土壤普查分级标准,余江县稻田土壤有机质、全氮、碱解氮和速效磷含量丰富,但速效钾含量处于中等水...对江西省余江县28个典型田块的调查结果显示,余江县稻田土壤以粉砂壤土和壤土为主,土壤pH值在4.78～5.37之间,属酸性土壤。参照第二次全国土壤普查分级标准,余江县稻田土壤有机质、全氮、碱解氮和速效磷含量丰富,但速效钾含量处于中等水平,少量田块还存在钾素缺乏的现象。2006～2008年28个定位田块平均年产量为12736 kg hm-2。主成分分析结果表明,影响当地水稻产量的主要土壤肥力因素是土壤有机质、全氮和碱解氮,速效钾的影响次之,再次是速效磷。因此,高度集约农业条件下土壤肥力指标值得进一步探讨;余江县在水稻生产过程中要加强有机肥的施用,增加钾肥施用,并适当减少磷肥的施用量。展开更多
基金Knowledge Innovation Project of Chinese Academy of Sciences No.KZCX3-SW-427+1 种基金 National Natural Science Foundation of China No.40171044
文摘The Yangtze delta area is among the fastest developing areas in China. Here there are mega-cities like Shanghai, Nanjing and the attached urban areas of different sizes including those along the lower reaches of the Yangtze River from Shanghai up to Nanjing as well as their satellite cities and towns, forming one of the most densely distributed urban areas in China. This is a case study done in Suzhou city at the center of the Yangtze delta to reflect the impact of urban sprawl on soil resources using satellite images and digital soil databases. The extent of the developed land in the studied area and the impact of development on soil resources at 1:100,000 scale are estimated and the soil types impacted most by urbanization development are determined through overlaying the soil map on the satellite images (Landsat-7) of the studied area at different times (1984, 1995, 2000 and 2003). The methodology for this study consists of analyzing data resulting from using a geographic information system (GIS) to combine urban land use maps of different times derived from satellite images with data on soil characteristics contained in the established soil databases by which some results come into being to present the fast expanding trend of urbanization in the Yangtze delta area, the urban spread and the soils occupied by the urbanization process, and also the quality of the occupied soils.
文摘对江西省余江县28个典型田块的调查结果显示,余江县稻田土壤以粉砂壤土和壤土为主,土壤pH值在4.78～5.37之间,属酸性土壤。参照第二次全国土壤普查分级标准,余江县稻田土壤有机质、全氮、碱解氮和速效磷含量丰富,但速效钾含量处于中等水平,少量田块还存在钾素缺乏的现象。2006～2008年28个定位田块平均年产量为12736 kg hm-2。主成分分析结果表明,影响当地水稻产量的主要土壤肥力因素是土壤有机质、全氮和碱解氮,速效钾的影响次之,再次是速效磷。因此,高度集约农业条件下土壤肥力指标值得进一步探讨;余江县在水稻生产过程中要加强有机肥的施用,增加钾肥施用,并适当减少磷肥的施用量。
