Abstract: By mowing stress mowing grassland of L.chinensis grassland in growing season,the regenerativity of its main population and community were studied.The results showed that different intensity and way of mowing stress greatly affected the population and community of herbage.As the increase of the intensity of mowing stress,the value of quantity characteristics of grassland herbage’s population and community dropped increasingly.The later the date of the second mowing,the clearer the dropping trend of growing potential.Especially L.chinensis population,its dropping range of growing potential was the biggest,showing that L.chinensis population was short of standing mowing.From the yield and quality of regenerative herbage,high yield of herbage and high total protein could be obtained by mowing twice,and that came second by mowing once or three times.If the second crop was used too early by mowing twice,the yield of herbage would be reduced strikingly.Mowing three times had extremely unfavorable effect on L.chinensis population.The first and the second crop had relatively high protein content.Using the grassland too late would also reduce protein content of herbage,making the herbage quality drop.Comprehensive analysis indicated that in order to bring the most productive forces of grassland into full play,and to give consideration to the essential factors of both yield and quality,as well as to keep the grassland in good growing state and mowing twice a year and utilizing(that was the treatment of July 5 and September 5)towards ideal.But what we deserved attention was to lie planting fallow and mowing in turn.If the grassland was mowed and utilized once a year,the optimum mowing time should be extended towards the and of July and August 2.Ultimately the study proved that the traditionalsystem of mowing and utilizing in the local area would squander the grassland resources greatly.Therefore,to tap the productive potentialities of grasslands fully,the pattern of their traditional mowing and utilizing treatments should be changed.

Key words: Mowing stress, Mowing Leymus chinensis grasslands, Herbage yield, Yield of crude protein, Regenerativity

摘要： 生长季内刈割胁迫羊草草原割草场,结果表明,胁迫强度与方式对草地主要种群和群落数量特征再生性影响较大;胁迫强度增强,其数量特征值下降幅度愈大,再次刈割时间愈后延,则下降愈明显,尤以羊草为显著,表明其耐刈性较差。就产质量而言,两次刈割可获得较高的牧草和蛋白质产量,一次或三次刈割则相对次之,尤其三次刈割不利影响极大;过晚利用会降低蛋白质产量,而影响牧草品质。研究证实,当地传统割草制度极大地浪费了草地资源,因此,要充分挖掘生产潜能,则须改变割草模式,科学利用,既兼顾产质量要素,又能保持草地处于良好的发育状态。

关键词: 刈割胁迫, 羊草草原割草场, 牧草产量, 蛋白质产量, 再生性