【作者】 刘静；

【导师】 庞奖励；

【作者基本信息】 陕西师范大学 ， 第四纪地质学， 2007， 硕士

【摘要】 土壤微形态直观地记录了土壤形成过程的各种信息（如矿物组成、物质的迁移、土地利用的方式、土壤发育的方向等等）。本论文通过对关中西部耕地和苹果林地土壤微形态研究，试图探索不同土地利用方式及利用时间对土壤微形态特征的影响，为该地区土地资源的可持续利用提供一些依据。本次研究选择了三种不同土地利用的土壤剖面作为研究对象，分别是：长期的农耕土壤、10年树龄的苹果林地土壤和20年树龄的苹果林地土壤。通过DMRX偏光显微镜对土壤微形态特征（包括粗颗粒特征和矿物组合、孔隙特征、微垒结类型、土壤形成物类型和分布特征等）进行了详细观察描述，采用SISC IAS V8.0图象分析软件对土壤粗颗粒和孔隙进行了定量分析和测量。通过研究，主要获得下列认识：1不同土地利用方式下土壤微形态有一定的差别。长期耕地的土壤微形态特征是：粗颗粒在Ap层C／F10μm值为0.35、定向性为91°、长度为23μm、宽度为14.3μm、圆度为0.1、粗糙度为0.3、长宽比为1.71，BC层C／F10μm值为0.26、定向性为92°、长度为21.4μm、宽度为13.2μm、圆度为0.11、粗糙度为0.3、长宽比为1.73，Bt层C／F10μa值为0.23、定向性为93.3°、长度为20.78μm、宽度为12.841μm、圆度为0.1、粗糙度为0.29、长宽比为1.73；微结构类型在Ap层和Bt层为海绵状结构，在BC层为团粒状结构；孔隙在Ap层以复合堆集状为主，少量孔道，边沿锯齿状，孔隙度主要为10.81％，在BC层和Bt层主要为孔洞，孔隙壁平滑，孔隙度分别为9.51％和9.18％；土壤形成物在Ap层以残积粘土浓聚物为主，其次为方解石，在深层可见针状碳酸盐，粘土矿物分布广泛，被铁不同程度的浸染。苹果林地土壤微形态特征是：粗颗粒在A层C／F10μm值为0.41、定向性为92.1°、长度为25.31μm、宽度为15.9μm、圆度为0.11、粗糙度为0.39、长宽比为1.69，BC层C／F10μm值为0.26、定向性为91.9°、长度为20.21μm、宽度为12.71μm、圆度为0.1、粗糙度为0.36、长宽比为1.65，Bt层C／F10μm值为0.3、定向性为89.7°、长度为21.98／μm、宽度为13.681μm、圆度为0.11、粗糙度为0.35、长宽比为1.71：孔隙在Ap层以简单堆集状为主，孔隙度为11.3％，在BC层和Bt层主要为孔洞，孔隙壁平滑，孔隙度分别为11.42％和8.1％；微结构类型在Ap层和Bt层为孔道结构，在BC层为海绵状微结构；具有大量铁染粘土和光性定向粘土分布，铁染团聚物广泛分布，偶见铁质结核。2土地利用时间对土壤微形态的影响。20年苹果林地土壤中，粗颗粒在A层C／F10μm值为0.41、定向性为92.1°、长度为25.31μm、宽度为15.91μm、圆度为0.11、粗糙度为0.39、长宽比为1.69，BC层C／F10μm值0.26、定向性为91.9°、长度为20.2μm、宽度为12.7μm、圆度为0.1、粗糙度为0.36、长宽比为1.65，Bt层C／F10μm值为0.3、定向性为89.7°、长度为21.98μm、宽度为13.681μm、圆度为0.11、粗糙度为0.35、长宽比为1.71；以简单堆集状大孔隙为主，孔隙度8.1-11.89％；微结构类型为孔洞-孔道为主；表层有较多量新鲜的植物残体出现，蚯蚓粪粒较少。10年苹果林地土壤中，粗颗粒在A层C／F10μm值为0.28、定向性为88.6°、长度为21.4μm、宽度为13.21μm、圆度为0.1、粗糙度为0.3、长宽比为1.7，BC层C／F10μm值为0.28、定向性为87.6°、长度为22μm、宽度为13.6μm、圆度为0.1、粗糙度为0.3、长宽比为1.73，Bt层C／F10μm值为0.22、定向性为86.5°、长度为21μm、宽度为13μm、圆度为0.11、粗糙度为0.32、长宽比为1.74，各个土壤发生层的粗颗粒变化较小；A层以复杂堆集状中小孔隙为主，BC和Bt层以孔道为主，整个剖面孔隙度在8.7-10.5％之间；微垒结类型以孔洞-孔道结构为主，又可见海绵状微结构类型；在表层可见大量的植物根系和大量的蚯蚓粪粒。3不同发生层的微形态特征明显不同。同一土壤剖面随着深度的变化微结构特征呈现明显的变化，以耕地为例来看：从Ap-BC-Bt层，C／F10μm值分别为0.35、0.26、0.23；长度分别为23、21、20：宽度分别为14.3、13.2、12.8：定向性分别为91、92、93；圆度分别为0.09、0.11、0.1，其中C／F值、长度、宽度由表层向下变化呈现出递减的规律，定向性的变化则表现为递增的规律，圆度呈现出先递增后递减的规律。不同层孔隙类型不同，在A层孔隙主要为堆集孔隙，在BC和Bt层为孔道，孔隙度也在发生着变化，从Ap-BC-Bt层分别为10.4％、9.5％、9.1％，随着深度的变化而逐渐降低。微结构类型在Ap₁层为中等分离的海绵状结构、Ap₂层为弱分离的海绵状结构、BC层为中等分离的团粒状结构、Bt层为海绵状结构。更多还原

【Abstract】 Soil micromorphology record the information of forming processes （such as mineral composition, material movement, land use, soil development direction, etc.）. Studying the micromorphological of farmland soil and Apple woodland soil in west of Guanzhong Areas, the thesis explore the influence of different land use on the soil micro-morphological characteristics, for the sustainable use of soil resources to provide some basis, The study choice three different land-use soil profile as research object, namely: long-term farming soil, ten years old Apple woodland soil and twenty years old Apple woodland soil. The research observe and describe the soil micro-morphological features （including coarse grains characteristics and mineral composition, voids characteristics, microstructure, the pedofeature, etc.） under the DMRX polarizing microscope, at the same time useing SISC IAS V8.0 optical image analysis software the research analysis and measures the coarse grains and voids characteristics. The results obtained in this study were the following major understanding:1. The soil micromorphological of different land use patterns have some differences. Soil micromorphology of long-term farmland: From coarse grains on Ap soil layers, C/F_10μm ratio is 0.35、orientation91⁰, length23μm、breadth14.3μm、roundness0.1、coarseness0.3、aspect ratio1.71, on BC Soil layers C/F_10μm ratio is 0.26、orientation 92⁰、length 21.4μm、breadth 13.2μm、roundness 0.11、coarseness 0.3、aspect ratio 1.73, on Bt soil layers C/F_10μm ratio is 0.23、orientation 93.3⁰、length 20.78μm、breadth 12.84μm、roundness 0.1、coarseness 0.29、aspect ratio 1.73; The microstructure of Ap and Bt are belong to the spongy microstructure, and the microstructure of BC is belong to grainy microstructure; Voids of Ap are complex stack voids and little channel, the voids edge is sawtooth, and voids ratio is 10.81 percent, BC and Bt vugh voids ratio are 9.51 percent; pedofeatures of Ap is abundand tesidual clay concretion and calcite. In apple woodland soil micromorphology: coarse grains on Ap soil layers, C/F10μm ratio is 0.41、orientation92.1⁰、length25.3μm、breadth15.9μm roundness0.11、coarseness0.39、Aspect ratio1.69, on soil layers of BC, C/F_10μm ratio is 0.26、orientation91.9⁰、length 20.2μm、breadth 12.7μm、roundness0.1、coarseness0.36、Aspect ratio 1.65, on Bt Soil layers C/F_10μm ratio is 0.3、orientation 89.7⁰、length 21.98μm、breadth 13.68μm、roundness 0.11、coarseness 0.35、Aspect ratio 1.71; Voids of Ap is briefness stack and voids ratio is 11.3 percent, on BC and Bt voids ratio of BC and Bt are11.42 percent or 8.1 percent; microstrueture are channel and spongy; there are lots of clay.2. Different land use time effect micromorphology. In twenty years old Apple woodland soil, coarse grains on A soil layers, C/F10μm ratio is 0.41、orientation92.10、length25.3μm、breadth15.9μm、roundness0.11、coarseness0.39、aspect ratio1.69, on BC Soil layers C/F10μm ratio is 0.26、orientation91.90、length 20.2μm、breadth 12.7μm、roundness0.1、coarseness0.36、Aspect ratio 1.65, on Bt Soil layers C/F_10μm 0.3、orientation 89.7⁰、length 21.98μm、breadth 13.68μm、roundness 0.11、coarseness 0.35、Aspect ratio 1.71; voids is briefness stack and voids ratio is 8.1 percent to 11.89 percent; With regard to the microstructure is belong to the vugh-channel complex; there are some origanic constituents and earthworm excrement. In ten years old Apple woodland soil, coarse grains on A Soil layers, C/F_10μm ratio is 0.28、orientation88.6⁰、length21.4μm、breadth13.2μm、roundness0.1、coarseness0.3、Aspect ratio1.7, on BC C/F_10μm ratio is 0.28、orientation87.6⁰, length 22μm、breadth13.6μm、roundness0.1、coarseness0.3、Aspect ratio 1.73, on Bt Soil layers C/F_10μm ratio 0.22、orientation 86.5⁰、length 21μm、breadth 13μm、roundness 0.11、coarseness 0.32、Aspect ratio 1.74; voids is complex stack and vugh, and voids ratio is 8.7 percent to 10.5 percent; With regard to the microstructure is belong to the vugh-channel complex; but have any spongy microstructure; There are some origanic constituents and lots of earthworm excrement.3. Soil micromorphology characteristic of different layers is significantly different. the microstructure characteristics of the same soil profile is changes with the depth, such as farmland: Form Ap to Bt, C/F_10μm ratio is 0.35、0.26、0.23; length 23、21、20; breadth 14.3、13.2、12.8; orientation91、92、93; roundness0.09、0.11、0.1.The C/F ratio、length and breadth are decrease by degrees, and the orientation is increase by degrees, at the same time the roundness is first increase by degrees then decrease by degrees. The voids types is change. In A soil layers, the voids type is stack, but in the BC and Bt soil layers are channel. At the same time the voids ratio are change. In Ap₁, the elementary fabric is moderately separated crumb microstrcture; In Ap₂,the elementary fabric is weakly separated crumb microstrcture; In BC, the elementary fabric is moderately separated Spongy microstrcture; In Bt, the elementary fabric is crumb microstrcture.更多还原