Micromorphological Features Of Apple Woodland And Farmland In West Of Guanzhong Areas

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.