Root characteristics of Cynodon dactylis and Trifolium repens and their effect on shear performance of purple soilin barren hillside

• Tao Zhou, 
• Xiao-hong Liu, 
• Yun Chen, 
• Run-ze Wang, 
• Tie Li, 
• Ting-ting Zhai, 
• Chen Wu, 
• Yong-qing Zong