摘要
在青藏高原东北缘—天祝县金强河地区进行了无芒雀麦 (Bromusinermis) 5 0 % +垂穗披碱草 (Clinelymusnutans) 5 0 %、无芒雀麦 5 0 % +多叶老芒麦 (Elymusnutans) 2 5 % +扁穗冰草 (Agropyroncristatum) 2 5 %、无芒雀麦 2 5 % +多叶老芒麦 2 5 % +垂穗披碱草 2 5 % +扁穗冰草 2 5 % ,3类禾草混播草地的放牧试验 ,研究了不同放牧强度对混播禾草草地牧草叶片特征和草地生产力的影响。结果表明 ,重牧 (70 %左右的采食率 )条件下 ,牧草和草群叶面积指数 (LAI)下降 (P <0 .0 5 ) ,叶片光合速率 (Pn)减弱 (P <0 .0 5 ) ,草地牧草现存量减少 (P <0 .0 5 ) ;轻牧 (30 %左右的采食率 )有利于无芒雀麦 +垂穗披碱草草地和无芒雀麦 +多叶老芒麦 +扁穗冰草草地补偿性再生和生物量积累 ,中牧 (5 0 %左右的采食率 )有利于无芒雀麦 +多叶老芒麦 +垂穗披碱草 +扁穗冰草草地补偿性再生和生物量积累。青藏高原高寒地区 ,前 2类混播草地适宜的放牧利用率为 30 %左右 ,后 1类混播草地适宜的放牧利用率为 5 0
A grazing experiment was conducted on three kinds of mixed pastures of perennial grasses, Bromus inermis 50% + Clinelymus nutans 50%(B+C), Bromus inermis 50%+ Elymus nutans 25% + Agropyron cristatum 25%(B+E+A), Bromus inermis 25% + Elymus nutans 25% + Clinelymus nutans 25%+ Agropyron cristatum 25%(B+E+C+A) with 27 Tibetan sheep at the age of 4-5-month-old by using random block design in alpine region of Tibetan Plateau, Jingqianghe region. The leaf characteristics and forage productivity under different grazing intensities were studied. Leaf area index (LAI) and leaf photosynthesis (Pn) rate of grass significantly decreased (P<0.05) at heavy grazing intensity (70% defoliation ratio). Higher sward regrowth and biomass accumulation of forage could be achieved on the grass mixtures of (B+C) and (B+E+A) at light grazing intensity (30% defoliation ratio) and on the grass mixture of (B+E+C+A) at medium grazing intensity (50% defoliation ratio). In the alpine region of Tibetan Plateau, 30% defoliation ratio should be applied on the grass mixtures of (B+C) and (B+E+A), and 50% defoliation ratio the grass mixture of (B+E+C+A) when they were grazed.
出处
《中国农业科学》
CAS
CSCD
北大核心
2004年第1期136-142,共7页
Scientia Agricultura Sinica
基金
中国科学院"百人计划"资助项目
甘肃省科委"九五"重点科技攻关资助项目(GK971 2 3 6A)
教育部第四届"优秀教师奖"资助项目
