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草业学报 ›› 2023, Vol. 32 ›› Issue (5): 94-105.DOI: 10.11686/cyxb2022228

• 研究论文 • 上一篇    下一篇

黄土高原典型草本植物根-土复合体抗剪性能的空间差异性及其影响因素研究

曹玉莹(), 苏雪萌, 周正朝(), 郑群威, 岳佳辉   

  1. 陕西师范大学地理科学与旅游学院,陕西 西安 710119
  • 收稿日期:2022-05-24 修回日期:2022-07-08 出版日期:2023-05-20 发布日期:2023-03-20
  • 通讯作者: 周正朝
  • 作者简介:E-mail: zczhou@snnu.edu.cn
    曹玉莹(1998-),女,吉林舒兰人,在读硕士。E-mail: yycao@snnu.edu.cn
  • 基金资助:
    国家自然科学基金项目(42277320);中央高校基本科研业务费(GK202001003);陕西省重点研发计划项目(2021ZDLSF05-02)

Spatial differences in, and factors influencing, the shear strength of typical herb root-soil complexes in the Loess Plateau of China

Yu-ying CAO(), Xue-meng SU, Zheng-chao ZHOU(), Qun-wei ZHENG, Jia-hui YUE   

  1. School of Geography and Tourism,Shaanxi Normal University,Xi’an 710119,China
  • Received:2022-05-24 Revised:2022-07-08 Online:2023-05-20 Published:2023-03-20
  • Contact: Zheng-chao ZHOU

摘要:

为探究黄土高原草本植物根-土复合体抗剪性能的空间差异性,由北至南分别以神木六道沟(砂壤土)、安塞坊塔(粉壤土)和永寿墚(粘壤土)3个不同土壤质地带的土壤为对象,采用盆栽的方式分别种植须根系的黑麦草和直根系的紫花苜蓿,并以裸地为对照。在种植4个月后,测定0~10 cm、10~20 cm和20~30 cm土层根-土复合体的土壤理化性质、根系特征和抗剪强度(粘聚力和内摩擦角)。结果表明:1)与裸地相比,种植黑麦草和紫花苜蓿后,有机质(SOM)、平均重量直径(MWD)和粘聚力(c)均得到增加,但内摩擦角(φ)变化较小,植物对土壤理化性质和抗剪强度的影响效应随土层深度的增加逐渐减小,黑麦草对改善土壤理化性质和抗剪强度的效果优于紫花苜蓿;2)在砂壤土、粉壤土和粘壤土质地下c呈现增加的趋势,根系参数和容重(BD)呈现减小的趋势,SOM和MWD表现为粘壤土>砂壤土>粉壤土,SOM、MWD和c增加值最大的为粘壤土;3)主成分分析显示砂壤土的根系特征指标对根-土复合体抗剪强度的贡献度比较高,粉壤土和粘壤土则是土壤特征指标对根-土复合体抗剪强度的贡献度比较高。研究结果综合评价了黄土高原草本植物根-土复合体的抗剪性能,为黄土高原水土保持研究提供了基础数据和理论参考。

关键词: 抗剪强度, 土壤质地, 主成分分析, 黄土高原

Abstract:

The aim of this study was to explore the spatial differences in the shear resistance of root-soil complexes of herbaceous plants on the Loess Plateau of China. Soils with three different textures were selected from three sites: From north to south, Liudaogou (sandy loam in Shenmu), Fangta (silty loam in Ansai), Yongshouliang (clay loam in Yongshouliang). Lolium perenne (with a fibrous root system) and Medicago sativa (with a tap root system) were planted in pots containing these soils. The soils without plants served as controls. After 4 months, the soil physicochemical properties, root characteristics, and shear strength (cohesion and internal friction angle) of root-soil complexes in the 0-10 cm, 10-20 cm, and 20-30 cm layers were measured. It was found that: 1) Soil organic matter (SOM), mean weight diameter (MWD), and cohesion (c) increased after planting L. perenne and M. sativa as compared to soils without plants, but the internal friction angle (φ) was basically unchanged. The influence of plants on the soil physiochemical and shear strength decreased with depth within the soil profile, and L. perenne had stronger effects than M. sativa on the soils’ physical and physicochemical properties and shear strength. 2) From sandy loam, to silty loam, to clay loam soils, c showed an increasing trend, andthe values of root parameters and bulk density (BD) decreased. The soils were ranked, from highest to lowest SOM and MWD, as follows: clay loam>sandy loam>silty loam. The highest values ofSOM, MWD, and c were in the clay loam soil. 3) A principal component analysis showed that root characteristics contributed significantly to the shear strength of root-soil complexes in sandy loam soil, while the soil characteristics contributed significantly to the shear strength of the root-soil complexes in silty loam and clay loam soils. This multivariate evaluation of the shear strength of root-soil complexes of herbaceous plants provides basic data and a theoretical reference for further studies of soil and water conservation on the Loess Plateau of China.

Key words: shear strength, soil texture, principal component analysis, Loess Plateau