Abstract: The effect of different clipping times and frequencies on the yield and regrowth rate of one-year pasture of mixedly cultivated Bromus inermis and Medicago varia Martin.cv.Caoyuan NO.3 were studied. The results showed that the first clipping date and the clipping frequencies remarkably effect the stability of the grassland. Yearly clipping during the Caoyuan NO.3 lucerne's blooming stage and the Bromus inermis' brewing tassel stage stabilizes the growth of the pasture. Clipping once a year promotes the growth of Caoyuan NO.3 lucerne, but reduces the component proportion of Bromus inermis. Clipping twice a year, thus the grassland stability is the best. Clipping once a year can be benefit to the growth of Caoyuan NO.3 lucerne, but reduces the component proportion of Bromus inermis. Clipping thrice a year would seriously affect the growth of component species. Bromus inermis regrows most vigorously within the 15 days after the clipping, not being affected by the period of time of clipping, while Caoyuan NO.3 lucerne's regrowing period is connected to the clipping time. Clipping at its blooming and podding stages accelerates Caoyuan NO.3 lucerne to gain plant height. The same clipping time suits Bromus inermis as well, while similarly raising its regrowth rate. In addition, clipping in the brewing bud and the late blooming stages would promote lucerne to grow rapidly with the 15 to 30 days after the clipping.

Key words: Clipping, Mixture grassland, Regrowth rate, Community stability, Species competition

摘要： 研究刈割对无芒雀麦+草原3号苜蓿草地的影响.结果表明:初次刈割时间和刈割次数对草地稳定性有显著影响;在苜蓿盛花期、无芒雀麦孕穗期刈割,刈割两次,草地稳定性最好;刈割一次有利于苜蓿生长,但降低无芒雀麦的比例;刈割三次则严重影响其生长发育;无芒雀麦在刈后1 d内再生速度最快,不受刈割期的影响,苜蓿再生草快速增长期与刈割期有关,在盛花期和结荚期刈割,株高快速增长期与无芒雀麦同步,再生速度也相似,在孕蕾期和盛花末期刈割,株高快速增长期出现在刈割后1～30d内.

关键词: 刈割, 混播草地, 再生速率, 群落稳定性, 种间竞争