刈割对混播草地种群生长与产量关系及种间竞争特性的影响

研究了不同刈割次数和时间下，混播草地中多年生黑麦草产量与叶片生长、分蘖数间的关系，白三叶产量与匍匐茎生长、分枝数间的关系，以及两者种间竞争特性变化。结果表明：黑麦草产量随分蘖数(年刈割8次和4次例外)或叶片生长长度增加呈弱显著或显著增加趋势，白三叶年产量与匍匐茎分枝数呈显著正相关；高频刈割利于黑麦草和白三叶种群生长的正效应发挥，低频刈割和对照增强种间个体的竞争；两者生长点数、种群产量关系由高频刈割的显著正相关向低频刈割和对照的显著负相关转化。可见，随刈割频率的降低和刈割日期的推后，黑麦草和白三叶的种间竞争渐趋明显。

Effects of cutting on the relationship between community growth and yield, and interspecific competition characteristics in mixed pasture

The relationships between herbage yield of perennial ryegrass and its number of tillers, and between herbage yield of white clover and its stolon branch number, and between the two species yields and growth in mixed pastures under different cutting frequency and cutting times were researched in this paper, along with changes in characteristics due to mutual competition The results indicated that annual herbage yield of ryegrass increased significantly with the number of tillers (exclusive of 8 and 4 cuts per year) or increase of its leaf length growth, while population yield of white clover related to the number of stolon branches High cutting frequency was beneficial for the growth and coexistence of the two species, whereas low cutting frequency increased the competition between them The relationship between number of growing points and population herbage yields of the two species was significantly positive at high cutting frequency and significantly negative at low cutting frequency It is obvious that interspecific competition gradually became evident as cutting frequency decreased and cutting date delayed