中文摘要：

目的研究崩岗洪积扇农田土壤颗粒组成、容重、土壤孔隙度、土壤持水情况、有机质并分析它们之间的相互关系，同时探索崩岗洪积扇农田土壤物理性质空间分异规律，不仅有利于农业用地规划，也为崩岗洪积扇农田土壤改良提供理论依据，对山区农林业生产具有重要的意义。方法运用野外调查结合室内分析的方法，以通城县杨垄小流域崩岗洪积扇农田为研究对象，选定水田和旱地两种洪积扇土地利用方式，分别采集洪积扇农田扇顶、扇中、扇缘以及对照4个区域测定其土壤物理性质，运用Pearson相关系数分析法对各指标之间的内在联系进行探究，研究崩岗对洪积扇农田的影响规律。结果崩岗侵蚀导致洪积扇农田土壤严重沙化，土壤结构性恶化。洪积扇农田土壤粗颗粒物质（砾石和砂粒）平均比对照区多75.89%，土壤细颗粒物质（粉粒和黏粒）平均比对照区减少39.13%。土壤有机质含量减少，洪积扇土壤有机质含量平均比对照区减少58.70%；容重增大，相对对照区平均增加0.25 g＆#183;cm-3；土壤孔隙度均小于对照区，饱和持水性和毛管孔隙度显著低于对照区。同时，沿着洪积扇扇缘到扇顶，土壤砾石和砂粒含量呈现逐渐增加，而粉粒和黏粒含量逐渐减少，容重随之增大，土壤孔隙度减少，持水性能也逐渐减弱，有机质逐渐减少的趋势。相关性分析得出，土壤容重与有机质含量呈极显著的负相关（R=-0.907＊＊），土壤容重与土壤孔隙性和土壤持水特性呈极显著的负相关，总孔隙度、毛管孔隙度与土壤持水特性均呈极显著的正相关，非毛管孔隙度与各物理性质之间没有明显的相关性。土壤各粒级大小与土壤容重、土壤持水性指标、总孔隙度和毛管孔隙度之间呈显著或极显著相关性。结论崩岗侵蚀发生后，洪积扇农田以土壤颗粒组成、有机质?

英文摘要：

Objective]The objective of this paper is to study the compositions of soil particles of the collapsing alluvial fan, bulk density, soil porosity, soil water-holding capacity, the organic matter, and to analyze the relationship among them. The spatial variation law of dilapidated granite alluvial fan farmland soil physical properties was also studied which is not only benefit to agricultural land-use planning, but also provide a theoretical basis for soil improvement of the collapsing alluvial fan farmland, thus,it has a profound effect on agriculture and forestry production in mountainous areas.[Method] In this paper, laboratory analysis and field survey methods were adopted to study the small watershed ridge collapse Tongcheng County alluvial fan of farmland. Both paddy and upland land use patterns of alluvial fan were selected, at the same time, soil physical properties of 4 areas in the farmland including the top, middle, margin of the alluvial fan and control trial which is outside the alluvial fan were collected, the Pearson correlation coefficient analysis method was adopted to explore the intrinsic link age between various indicators to understand effect of collapse mound on alluvial fan farmland.[Result]Collapsing erosion causes serious alluvial fan farmland soil desertification and soil structural deterioration. Coarse alluvial fan farmland particulate matter （gravel and sand） were more than 75.89% compared with the control area on average, soil fine particulate matter （silt and clay） reduced by 39.13% on average compared to the control area. Soil organic matter content was reduced, soil organic matter content in alluvial fan soil reduced by 58.70% compared with the control area on average; bulk density increases, relative to the control area increased an average by 0.25 g＆#183;cm-3; soil porosity were less than the control area, and saturation and capillary water holding capacity were significantly lower in the control area. Meanwhile, along the edge of the alluvial fan to fan roof, gravel and