关中地区两种不同农业管理方式下土壤微形态特征

 【目的】通过对关中地区不同土壤微形态特征的研究和对比，试图阐明农业管理方式对土壤发育过程和方向的影响。【方法】用偏光显微镜和NIKON NISBR2.2软件对土壤微形态进行了观察和分析。【结果】灌溉和非灌溉土壤均具有Ap1-Ap2-BC剖面构型, 但前者分异更明显；粗颗粒矿物组合均以石英和长石占绝对优势；与非灌溉土壤相比, 灌溉土壤Ap1和Ap2层中颗粒的长度、等圆直径、周长、面积、圆度、C/F(10μm)值降低的程度更大，残积粘土数量更多且出现一定数量的淀积粘土，孔隙形态更规则和孔壁更光滑。【结论】农业管理方式对土壤剖面分异和微形态有显著的影响；农业生产过程中的灌溉可增强风化强度，使颗粒形态细化和园化程度增强，残积粘土数量显著增加且可出现淀积粘土，但对粗颗粒主要矿物组合影响不明显。

Comparison of Micromorphological Features of Two Agricultural Cultivated Soils in Guanzhong Areas of Shaanxi Province

【Objective】To compare micromorphological features of both irrigated and non-irrigated soil in Guanzhong Areas, this paper try to illustrate farming method influences on soil-forming process of soil.【Method】Micromorphology is observed under a petrographic microscope and its image is quantificationally measured by Qwin3.1 software. 【Result】 Both irrigated soil and non-irrigated soil have the same as soil profile type,Ap1- Ap2- BC, but the former has a more obvious profile difference. The minerals assemblage of different horizon is very similar, which is mainly composed of Q and Pl. Compared with non-irrigated soil, coarse of irrigated soil is characterized by Length, Area, EqDiameter, Perimeter, Elongation, Roundness, MeanChord and C/F(10μm) ratio; voids are characterized by more regular void shape and more smooth void wall; there are more abundant residual clay and little amount illuvial clay. 【Conclusion】All the results in this study suggest that farming method has the influence on the soil profile difference and micromorphology. The agriculture irrigating could strengthen the degree of weathering, making smaller and rounder coarse, increasing quantities of residual clay and appearing illuvial clay, no-changing minerals assemblage of coarse.