黏土对沙地土壤改良效果的微形态研究——以内蒙古科尔沁沙地为例

为了研究施加黏土后的沙地土壤微形态特征,说明其改良效果,对内蒙古科尔沁沙地土壤切片进行观察,并利用土壤切片图像处理分析系统和Image-Pro Plus 6.0软件进行处理和分析,提取基质、孔隙和粗骨颗粒等和土壤肥力状况相关的定量化数据进行分析及定性分析,结果表明:施加黏土后,出现了块状微结构和雏形团聚体;从基质比、毛管孔隙占比方面来说,底施处理效果更好,基质比在C2(3×10~5 kg/hm~2)处理水平比对照组提高了8.8%,毛管孔隙占比在C3(6×10~5kg/hm~2)处理水平提高了15%;就总孔隙百分比、粗骨颗粒磨圆度、粉粒百分比、粗骨颗粒平均粒径来说,表施处理效果比较好,C1(1.5×10~5 kg/hm~2)、C2(3×10~5 kg/hm~2)处理水平均有显著改善。结论:1)施加黏土后,沙地土壤结构与原始沙地的粒状微结构相比有一定的改善;2)短期底施处理下,C1和C2处理单元的基质比有所提高,毛管孔隙占比随着黏土施加量的增加而提高;粗骨颗粒特征方面,表施处理效果比底施效果要好;3)短期改良情况下,沙地土壤微结构并没有太大的变化,还是以粗骨颗粒为主,但改良后出现一些雏形团聚体,各量化指标均有不同程度的提高。

Micromorphological research on the effect of sandy soil improvement with clay: A case study of Horqin Sandy Land in Inner Mongolia

To research the soil micromorphological features of sandy land after applying clay and explore the effect of the ameliorative measures from the aspects of soil micromorphology, soil collected from Horqin Sandy Land of Inner Mongolia were made into soil thin sections,the analysis was proceeded by observing the soil thin sections and collecting the quantitative data of soil matrix,pores and skeleton grains by using the soil slice image processing and analysis system and the software of Image-Pro Plus 6.0.The results showed that:The soil microstructure was improved after applying clay,blocky microstructure and cambic aggregate were found; In terms of matrix ratio and capillary pore ratio,the effect of subsoil application was better,the matrix ratio was increased by 8.8% at the level of C2 (3×10⁵kg/hm²), and the capillary pore ratio was increased by 15% at the level of C3 (6×10⁵kg/hm²);However in terms of total soil porosity,roundness,the ratio of silt area and average diameter,the effect of surface application was better. All were improved significantly at the level of C1(1.5×10⁵kg/hm²) and C2(3×10⁵kg/hm²).In conclusion1)the sandy soil structure has improved after applying clay. 2) In the short term at subsoil application,the matrix ratio was increased at the levels of C1 and C2,the capillary pore ratio was increased with the increase of clay amount.And the effect of surface application was better as for skeleton grains;3) In the short term after the amelioration,there was no great improvement in soil microstructure,which was dominated by skeleton grains and with small amount of cambic aggregate,and all quantitative index were improved to some extent.