Sha Xiao-Yan, Li Kui, Wang Wen-Long, Lou Yi-Bao, Kang Hong-Liang, Feng Lan-Qian, Nie Hui-Ying
State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Northwest A＆F University, Yangling 712100, Shaanxi, China.
Administrative Examination and Approval Service Bureau of Yangling Demonstration Zone, Yangling 712100, Shaanxi, China.
Ying Yong Sheng Tai Xue Bao. 2022 Jan;33(1):133-140. doi: 10.13287/j.1001-9332.202201.027.
Vegetation restoration in the Chinese Loess Plateau has significantly changed soil erosion process of gully head wall. In order to investigate the characteristics and controlling factors of soil anti-scour properties of gully head covered by grasses, we carried out indoor undamaged soil trench scouring tests. By using barren gully head as the control, the physical and chemical properties and anti-scouring characteristics of soil in different soil layers (0-10, 10-20, 20-40, 40-60, 60-80, 80-100 cm) of the vertical wall of gully with grass cover were analyzed. The results showed that water-stable aggregate content and cohesion in barren and grass-covering gully head decreased with soil depth. Soil organic matter content and soil anti-scouribility coefficient in barren gully head decreased with soil depth, while the two indicators for gully head covered by grass increased firstly and then decreased with soil depth, with the maximum value (24.30 g·kg and 58.86 L·g) in 10-20 cm soil layer. Meanwhile, the soil anti-scouring coefficient in each soil layer of grass-covering gully head was 1.7-9.3 times of that in soil layer of barren gully head. Soil organic matter content, water-stable aggregate content, cohesion and root length density all presented significantly positive correlation with soil anti-scouribility, among which soil organic matter content had the highest coefficient (=0.98). Results of this study might provide basic data for the study of headcut erosion mechanism in Loess Plateau gully region, and scientific basis for effective control of soil and water loss in this region.
中国黄土高原的植被恢复显著改变了沟头壁的土壤侵蚀过程。为了研究草丛覆盖沟头土壤抗冲性特征及控制因素，开展了室内原状土槽冲刷试验。以裸沟头为对照，分析了草丛覆盖沟壁不同土层（0 - 10、10 - 20、20 - 40、40 - 60、60 - 80、80 - 100 cm）土壤的理化性质和抗冲特性。结果表明，裸沟头和草丛覆盖沟头的水稳性团聚体含量和黏聚力均随土层深度减小。裸沟头土壤有机质含量和土壤抗冲系数随土层深度减小，而草丛覆盖沟头的这两个指标随土层深度先增大后减小，在10 - 20 cm土层达到最大值（24.30 g·kg和58.86 L·g）。同时，草丛覆盖沟头各土层的土壤抗冲系数是裸沟头土层的1.7 - 9.3倍。土壤有机质含量、水稳性团聚体含量、黏聚力和根长密度均与土壤抗冲性呈显著正相关，其中土壤有机质含量的相关系数最高（=0.98）。本研究结果可为黄土高原沟壑区溯源侵蚀机制研究提供基础数据，为该区域水土流失的有效治理提供科学依据。
