长期刈牧利用下贵州高原黑麦草+白三叶草地养分和植被构成变化

Change of nutrients and botanical composition of mixed Lolium perenne╋Trifolium repens grasslands under long-term grazing and mowing utilizations

对贵州高原长期割草(M)、割草+放牧(M+G)、连续放牧(CG)和轮牧休闲(RG)4种利用方式下,黑麦草(Lolium perenne)+白三叶(Trifolium repens)草地土壤和牧草养分及植被构成进行系统分析,为该类草地的持续利用提供实践依据。结果表明,土壤养分含量变化复杂,CG草地土壤酸化严重,M草地牧草Ca含量和RG草地牧草P含量较高,CG草地牧草Mg含量较低,M和M+G草地牧草Cu含量较高,牧草营养价值在4种利用方式间无显著差异。黑麦草分蘖密度为RG>M+G>M=CG,分蘖质量为M=M+G>CG=RG;白三叶匍匐茎密度和匍匐茎质量为M=RG>M+G=CG。植物物种数为CG>M=M+G>RG。CG草地群落结构复杂,主要由黑穗画眉草(Eragrostis pilosa)构成,M草地主要由白三叶+蒲公英(Taraxacum officinale)+白苞蒿(Artemisia lactiflora)构成,M+G和RG草地群落结构简单,仍主要由播种黑麦草+白三叶构成。割草+放牧(M+G)和轮牧休闲(RG)为研究区黑麦草+白三叶草地长期利用的较适宜方式。

Effect of mowing （ M） , mowing ＋ grazing （ M ＋ G） , continuous grazing （ CG） and rotationalgrazing （RG） on the nutrients of soils and herbagevS, and the botanical composition of mixed Loliumperenne Trifolium repens pasture on Guizhou plateau were quantity monitored and analyzed, whichwould provide some practical basis for the grassland sustainable utilization. The results showed that, thecontents of the nutrition in soil varied largely,the soil of CG grassland was severely acidification. Forherbage, contents of Ca in M grassland,P in RG grassland, Cu in M and M ＋ G grassland were higherthan the other, and content of Mg in CG was lowest; while the nutritive values of four treatments had nosignificant difference. The number of tillers of L. perenne were RG M ＋ G〉M = CG,and the tillerweight were M = M ＋ G〉CG = RG; while the density and weight of T. re pens stolon were M = RG〉-M ＋ Gand CG. The number of species were CG〉 M = M ＋ G〉RG. The community structure of CG grasslandwas complex and dominated by Eragrostis pilosa,M grassland dominated by T. repens＋Taraxacum officinale＋Artemisia Lactiflora ; while the community structure of M ＋ G and RG grassland were simple anddominated by L. perenne^rT. re pens. Thus,ultilization method of M ＋ G and RG were more suitable forlong term grassland utilization in research area.