Effects of utilization modes, planting patterns, and nitrogen applications on the yield and quality of perennial forage

• XIAO Xiangming, 
• CHANG Shenghua, 
• JIA Qianmin, 
• PENG Zechen, 
• ZHANG Cheng, 
• LIU Yongjie, 
• WU Enping, 
• HOU Fujiang