“改排为蓄”和“覆沙改良”整治前后盐碱地微观结构研究

【目的】从微观层面研究不同治理措施整治前后盐碱土结构变化,土壤结构与土壤性质相互作用,微结构变化对土壤性质的改善作用。【方法】对渭南市富平县褚原村"对流弥散"和"覆沙改良"试验小区的原状土进行采集,采用扫描电镜及能谱仪对采取"改排为蓄"和"覆沙改良"法整治前后的盐碱土进行微观形貌观测和元素组成分析。【结果】整治前盐碱土板结较严重,孔隙结构差,经淡水洗盐并经合理蓄水处理后的盐碱土颗粒变小,结构上呈片层状,利于水盐向下运移并有利于阻止返盐,"覆沙改良"法随着覆沙厚度的增加(5～15 cm),非毛管孔隙增多,土壤孔隙结构逐渐改善。【结论】对比"改排为蓄"和"覆沙改良"法整治后盐碱土微结构,"覆沙改良"法使土壤结构发生的变化较大。

Influence of Different Soil Organic Reconstruction Methods on Microstructure of Saline-Alkali Soil

【Objective】In order to study the structural changes of saline-alkali soils before and after remediation with different treatment measures at the micro-level, the interaction between soil structure and soil properties was explored, and the effect of microstructural change on soil properties was discussed.【Method】The original soil of the experimental plot of "convection dispersion" and "sand cover improvement" were collected in Chuyuan Village, Fuping County, Weinan. The soil remediated before and after"the change from draining water to storing water"or"remediation by sand blending"methods was characterized by scanning electron microscope and energy dispersive spectrometer.【Result】The saline-alkali soil hardened seriously before remediation, and the pore-structure was poor. By washing the saline-alkali soil with water and stroring the washed water locally, the saline-alkali soil particles became smaller and the structure was lamellar, which facilitated the downward movement of water and salt and prevented the upward movement of water and salt. When remediating by sand blending, with the increase of sediment thickness of sand(5～15 cm), non-capillary pores increased and soil pore structure gradually improved.【Conclusion】Compared with the two methods of "the change from draining water to storing water" and "remediation by sand blending", the microstructure of saline alkali soil changed greatly by "the change from draining water to storing water ".