| 香根草根系与土壤接触特性及抗拔模型研究 |
| Vetiver Root-soil Contact Characteristics and Pull-out Model |
| 投稿时间：2015-08-04 修订日期：2016-08-10 |
| DOI：10.15928/j.1674-3075.2016.04.006 |
| 中文关键词:香根草 埋置深度 接触特性 抗拔力 粘滞强度 |
| 英文关键词:Vetiveria Zizanioides embedment depth contact characteristics anti pull force viscous strength |
| 基金项目:科学技术部“十二五科技支撑”（2012BAC06B02-04）；国家自然科学基金“三峡库区紫色土的植物根系加固效应与机制研究”（41202250）；长江水利委员会长江科学院开放研究基金资助项目：三峡库区植物根系增强紫色土抗水侵蚀效应与机理研究（CKWV2015208KY）；三峡大学研究生科研创新基金项目（2015CX026） |
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| 中文摘要: |
| 为了探索草本根系与土壤的接触特性，并分析其单根抗拔模型，通过控制根系直径、埋置深度和土壤含水率在不同梯度下，采用施加拔出荷载的方式对香根草(Vetiveria zizanioides)进行单根抗拔实验。结果表明，香根草根系单根抗拔力随根系直径的增大而增大，粘滞强度随根系直径的增大而减小，两者均与根系直径呈幂函数关系；抗拔力随根系埋置深度的增加而增加，粘滞强度随根系埋置深度的增加而减小，两者与根系直径也均呈幂函数关系，但埋置深度的增加对抗拔力和粘滞强度的变化影响较小；根系单根抗拔力和粘滞强度，随土壤含水率的增加呈先增大、后减小的趋势，其中在最佳含水率时，单根抗拔力和粘滞强度均达到最大；通过对粘滞强度与根系直径关系拟合，得出幂函数（R2=0.898）拟合曲线比线性函数（R2=0.854）更优；抗拉力、粘滞强度与埋置深度拟合，随着埋置深度的增加，得出拟合函数分别为Y1=0.937H 0.578，Y2=34.59H-0.470；香根草根系的抗拔力整体上随着土壤含水率的增加，呈先增大、后减小的趋势。在土壤含水率小于14%时，抗拔力增长幅度大；土壤含水率达到14%，抗拔力最大；含水率为17%～23%时，根系抗拔力下降幅度小，基本趋于稳定；含水率大于23%时，抗拔力迅速下降；在香根草根系单根抗拔力随埋置深度的拟合曲线中，得到该控制条件下根系临界长度公式：Lcr=582.67D1.7388，在土壤含水率为14%时，香根草单根根系的临界长度随根系直径的变化规律为幂函数增长。 |
| 英文摘要: |
| The interaction between plant roots and soil is well known and roots play a key role in stabilizing soil, especially on sloped land. However, there is no consensus on how the plant root system and the physical parameters of soil influence the contact properties of plant root to soil, or how the anti-pull force of the plant root change with these factors. Vetiveria zizanioides is a good perennial herb for slope protection with extensive adaptability and excellent stress resistance. In this study, we investigated the properties of Vetiveria zizanioides root to soil contact and analyzed the pulling resistance of a single Vetiveria zizanioides root to different pull-out experiment designs involving the root diameter, embedment depth, and soil moisture content. Results quantitate the increase in tensile strength and the decrease in viscous strength with root diameter. Both tensile strength and viscous strength are related to root diameter by a power function. The tensile strength of a single plant increased with embedment depth and the viscous strength decreased with embedment depth, but embedment depth had little effect on the anti-pull force and viscous strength. The tensile strength and viscous strength of a single Vetiveria zizanioides root both increased initially and then decreased with soil moisture, reaching maximum values at the optimum moisture content. When the soil water content is less than 14%, the tensile strength increased quickly with moisture. When the soil water content is 17% - 23%, the tensile strength was more stable, but declining slightly. When the soil content is more than 23%, the tensile strength declined rapidly. The power function (R2=0.898) of viscous strength and root diameter is a better fit than a linear function (R2=0.854). The relation between the tensile strength, viscous strength and the embedment depth is described as Y1=0.937H0.578，Y2=34.59H-0.578. Under controlled conditions, using the fitting curve of tensile strength and embedment depth, the root critical length formula was obtained: Lcr=582.67D1.7388 . At a soil moisture content of 14%, the critical length of a single Vetiveria zizanioides root changed regularly with root diameter, following the power function Lcr=ADB, where A and B are empirical constants. |
| 夏振尧,张伦,陈毅,薛海龙,许文年.2016.香根草根系与土壤接触特性及抗拔模型研究[J].水生态学杂志,37(4):36-41. |
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