基于CT扫描技术的土柱孔隙结构及其抗侵蚀能力研究——以种植百喜草为例  

A Study on Pore Structure and Erosion Resistance of Soil Column Based on CT Scanning Technology—Taking Bahiagrass Plantation as an Example

作　　者：张亭[1] 施明明 李鑫[2] 王新军[3] 曹龙熹 Zhang Ting;Shi Mingming;Li Xin;Wang Xinjun;Cao Longxi(College of Ecology and Environment,Chengdu University of Technology,Chengdu,Sichuan 610059,China;College of Earth Sciences,Chengdu University of Technology,Chengdu,Sichuan 610059,China;China Academy of Transportation Sciences,Beijing 100029,China)

机构地区：[1]成都理工大学生态环境学院,四川成都610059 [2]成都理工大学地球科学学院,四川成都610059 [3]交通运输部科学研究院,北京100029

出　　处：《水土保持通报》2023年第5期148-155,共8页Bulletin of Soil and Water Conservation

基　　金：国家重点研发计划项目“陆路交通基础设施与生态环境协调机制研究及集成示范”(2021YFB2600105)。

摘　　要：[目的]分析百喜草土柱孔隙结构与土壤抗侵蚀能力之间的联系,为水土保持植物措施的优化布设以及效益评估提供科学依据。[方法]依托植物土柱长期微区试验,通过CT扫描技术研究种植百喜草的土柱孔隙指标(孔隙长度密度、体积密度、表面积密度和孔隙数密度),开展边坡水槽冲刷试验。设置3个坡度(10°,20°和30°)和5个流量(0.8,1.6,2.4,3.2,4.0 L/s)组合量化土壤抗侵蚀能力,分析孔隙指标与抗侵蚀能力因子之间的关系。[结果]百喜草土柱孔隙发育程度随生长时间不断增强,而随土层深度减弱;4个孔隙结构指标在0—5 cm土层的数值远大于5—10 cm土层,且表层0—5 cm的平均土壤细沟可蚀性(0.026 s/m)和临界水流剪切力(7.0 Pa)分别是下层5—10 cm的0.33,1.54倍。[结论]植物根系发育的孔隙指标能够表征土壤抗侵蚀能力变化,CT扫描获取的4个孔隙结构指标与细沟可蚀性等因子显著相关,其中孔隙表面积密度与土壤抗侵蚀能力指标关系最为密切。[Objective]The relationship between soil column pore structure and soil erosion resistance for soil columns with Bahiagrass was analyzed in order to provide a scientific basis for the optimal arrangement of plants for soil and water conservation and to assess the benefits of planting Bahiagrass.[Methods]This study was conducted using long-term experiments of Bahiagrass grown in soil columns.Four pore indicators(pore length density,bulk density,surface area density,and pore number density)of Bahiagrass soil columns were quantified by CT scanning technology.Flushing tests using a flume with variable slopes were carried out to quantify soil erosion resistance at three slopes(10°,20°,and 30°)and five runoff rates(0.8,1.6,2.4,3.2,and 4.0 L/s).The relationships between pore structure characteristics and erosion resistance factors were then determined.[Results]Bahiagrass root system development increased during the growth period,but decreased with soil depth.The values of four pore structure indicators in 0—5 cm soil layer were much higher than those in 5—10 cm soil layer,and the average soil rill erodibility(0.026 s/m)and critical shear stress(7.0 Pa)in 0—5 cm surface layer were 0.33 and 1.54 times the values of those respective parameters in 5—10 cm lower soil layer.[Conclusion]The pore characteristics of plant root development indicated soil erosion resistance.The four pore structure indicators obtained by CT scanning were significantly related to factors such as rill erodibility.The pore surface area density was most closely related to the erosion resistance factors.

关 键 词：百喜草 CT扫描 孔隙结构 土壤分离速率 细沟可蚀性 

分 类 号：S154.4[农业科学—土壤学] S157[农业科学—农业基础科学]