刈割对混播草地根重及翌年产草量的响应

研究刈割对无芒雀麦Bromus innermis 草原3号苜蓿Medicago varia cv.Caoyuan No.3草地组分种根重及翌年产草量的影响.结果表明:刈割次数对牧草根重和产草量有显著影响;随着刈割次数的增加,苜蓿和无芒雀麦根重下降,刈割3次比刈割1次根重分别下降53.39%和29.88%.在试验组分频率下,播种当年刈割1次,有利于苜蓿生长,翌年草地总产量最高,但降低了无芒雀麦的比例;在苜蓿孕蕾期(无芒雀麦拔节后期)初次刈割,年刈割2次,翌年草地产草量较高,群落稳定性最好;刈割3次,则严重影响其生长发育.

Effect of seeding-year clipping frequency on root weight and yield in alfalfa and brome grass mixture swards

Clipping frequency remarkably affected root weight in seeding year and yield in next year in mixture swards of alfalfa and brome grass.Root weight for both alfalfa Caoyuan No.3 and brome grass dropped with the increase of cutting times.Root weight under three cuts for Caoyuan No.3 and brome grass reduced by 53.39% and 29.88% respectively,compared with those under cut once.Cut once in seeding year benefited to alfalfa growth with better next year yield,brome grass proportion in the mixture declined.Maximum alfalfa yield occurred at blooming stage with two cuts within the year.Cut three obviously had negative effect on alfalfa growth in the region.