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

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