Through cutting natural grass plants in the Guizhou Karst mountain area ,we made out control,0 time （CK group）, 1 time, 2 times, 3 times and 4 times in different treatments without fertilization,irrigation and so on in one year. Analysis results showed that, （1）Cutting grass compared with the control （CK）,different treatments A1,A2,A3,A4 withered periods were postponed by 18d, regreen stages were ahead of 15d,1 1d,9d,5d respectively in 2009. （2）There was a linear relationship among natural grassland yield, height and coverage ,the equation was： Y = 2.54X1 ＋4.38X2-94.74, R^2 = 0.9410. The dry weight had significant difference （ P 〈0.05 ）, the ratio of dry and fresh yield decreased with cutting frequency increased. The lower the ratio of dry and fresh was,the higher the forage moisture content was and the better the quality of forage was. （3） There was a ＂ peak＂ of growth rate on the second cutting for A2, A3 and A4 treatment. We knew to the growth rate an inflection formed for N4 in May 12th, the growth rate increased rapidly after the time, and the growth rate reached peak in July 15th, followed by gradual decline, the second turning point was formed in September 19th. Comprehensive analysis and conclusion, the optimal cutting times were for 2 or 3 times in mountainous area in Karst natural grassland ,we took the first harvest time in the middle of July, so that regrowth grass yield could increase 0.7 - 1.1 time, that would realize economic benefits and ecological benefits double win.%通过对贵州喀斯特山区天然草地植被的刈割试验，在无施肥、灌溉等农艺措施的条件下，对天然草地植被采取年刈割0次（对照CK）、1次、2次、3次、4次共5个处理，试验结果表明：刈割草地与对照相比，不同处理A1、A2、A3和A4间植被的黄枯期都推迟了18d，2009年返青期分别提前了15d、11d、9d和5d；天然草地植被产量与高度、盖度间存在线性关系，其方程为：Y=2．54X1＋4．38X2-94．74，R^2=0．9410。其风干重间差异显著（p〈0．05），干鲜比随刈割次数的增加而降低。干鲜比越低，牧草含水量越高，牧草品质越好；A2、A3、A4处理间生长速率都在第2次刈割出现“峰值”，从A4得知，生长速率在5月12日形成一个拐点，过后生长速率迅速增加，到7月15日达到高峰。之后逐渐下降，9月19日形成另一个拐点。综合分析得出结论，在贵州喀斯特山区天然草地植被年刈割适宜次数为2次或3次，第1次刈割时期为7月中旬，可再增加0．7—1．1倍产量，实现经济效益与生态效益共赢。
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