草本植物根系类型和分布对根土复合体无侧限抗压强度的影响  

Effects of Herb Root Type and Distribution on Unconfined CompressiveStrength of Root-Soil Composites

作　　者：刘向峰[1] 张强 郝国亮 王逸腾 孙颖聪 王来贵[1] LIU Xiang-feng;ZHANG Qiang;HAO Guo-liang;WANG Yi-teng;SUN Ying-cong;WANG Lai-gui(College of Mechanics and Engineering,Liaoning Technical University,Fuxin 123000,China)

机构地区：[1]辽宁工程技术大学力学与工程学院,辽宁阜新123000

出　　处：《长江科学院院报》2023年第9期106-111,117,共7页Journal of Changjiang River Scientific Research Institute

基　　金：国家重点研发计划项目(2017YFC1503101)。

摘　　要：为了探究草本植物根系类型和分布对根土复合体无侧限抗压强度的影响,采用图片像素转换法确定轴根型紫花地丁、根蘖型苦荬菜和根茎型水麦冬在不同土壤深度的根系分布特征;并利用无侧限抗压试验获取3种草本植物根土复合体的应力-应变曲线,量化根土复合体的抗压强度,探究根土复合体破坏面根系参数与黏聚力增量的关系。研究结果表明,在0~8 cm土壤深度范围内,随土壤深度的增加,轴根型紫花地丁和根茎型水麦冬的根长密度RLD、根表面积密度RASD、根面积比RAR逐渐减小,而根蘖型苦荬菜的RLD、RASD、RAR出现了先增大后减小的趋势。3种草本植物根系分布特征参数的量化结果均表现为紫花地丁>水麦冬>苦荬菜。根茎型水麦冬提升土体抗压强度的能力最优,其根土复合体黏聚力增量分别是紫花地丁和苦荬菜黏聚力增量的1.42、2.6倍。3种草本植物破坏面的RLD、RASD和RAR均表现为水麦冬最大,苦荬菜最小,紫花地丁居中。苦荬菜破坏面根系参数与黏聚力增量无相关性。对于轴根型和根茎型草本植物,根土复合体破坏面的3个根系分布参数中,RAR与黏聚力增量的相关性明显高于RLD和RASD。因此,RAR可以作为预测根茎型和轴根型草本植物提高土体抗压强度能力的重要参数。To investigate the impact of herb root type and distribution on the unconfined compressive strength of root-soil composites,the root distribution characteristics of cluster-root Viola philippica,tiller-root Ixeris polycephala,and rhizome-root Triglochin Palustre within different soil depths were determined using an image pixel conversion algorithm.Stress-strain curves of the three herb-root-soil composites were obtained through unconfined compressive tests.The relationship between root parameters and cohesion increment of the failure surface of the root-soil composites was examined by quantifying the compressive strength.Results indicated that within the 0-8 cm soil depth range,the root length density(RLD),root surface area density(RASD),and root area ratio(RAR)of Viola philippica and Triglochin Palustre gradually decreased with increasing soil depth,while Ixeris polycephala displayed an increasing trend followed by a subsequent decrease.Quantitative root distribution parameters of Viola philippica ranks first,followed by Triglochin palustre and Ixeris polycephala in sequence.Rhizome-root Triglochin palustre exhibited the highest ability to improve soil compressive strength,with the cohesion increment of its root-soil composite being 1.42 and 2.6 times those of Viola philippica and Ixeris polycephala,respectively.Triglochin palustre has the largest RLD,RASD and RAR of the failure surface,followed by Viola philippica and Ixeris polycephala in sequence.No correlation was observed between root parameters and cohesion increment of the failure surface of Ixeris polycephala.For cluster-root and rhizome-root herbs,RAR has larger correlation with cohesion increment than RLD and RASD do.Therefore,RAR can serve as an important predictor of soil compressive strength improvement for cluster and rhizome root types.

关 键 词：根系类型 无侧限抗压强度 根土复合体 根长密度 根表面积密度 根面积比 

分 类 号：S157.43[农业科学—土壤学]