中文摘要：

通过田间试验研究了留茬10cm、20cm和40cm刈割对红三叶生长特性、净光合速率和PSII最大光化学效率的影响。结果表明，留茬20cm刈割红三叶叶片净光合效率较高、有效光合时间较长，分蘖数居中、分枝数多，总产量高，有利于红三叶的持续生产。综合分析认为，20cm为红三叶的适宜刈割高度。

英文摘要：

The effect of different mowing heights which were 10cm, 20cm and 40cm on red clover growth characters, net photosynthetic rate and maximal photochemical efficiency of PSII （Fv/Fm） were investigated. The results showed that at the 20cm stubble height, red clover had the higher photosynthetic efficiency, longer effective photosynthetic time, moderate tillers, more branches and high total product, which was conducive to the sustainable production of red clover. Therefore, the suitable mowing height of red clover was 20cm.