刈割对多年生黑麦草分蘖与叶片生长动态及生产力的影响

对不同刈割强度和时间下 ,混播草地中多年生黑麦草净分蘖数和叶片生长季节动态及其年积累和年产量进行了 2年的比较研究。结果表明 :叶片净生长与净分蘖数季节动态具有相互弥补的特点。刈割不利于多年生黑麦草的分蘖 ,所有刈割处理均不存在分蘖的“超补偿生长”效应 ;净分蘖数随刈割次数的增加而降低 ;高频刈割对分蘖的抑制效应逐年加强 ,低频刈割对分蘖的抑制效应逐年减弱。叶片生长对刈割处理的超补偿效应显著 ;刈割能刺激多年生黑麦草叶片的生长 ,提高年净生产力 ,维持混播草地中黑麦草的组分 ,增强黑麦草的竞争能力。刈割对多年生黑麦草年净生产力的提高主要是通过刺激其叶片的生长来实现的。叶片净生长与净分蘖数的年积累存在显著负相关 (R=- 0 .893,P<0 .0 5)

Effects of cutting on dynamics of tiller and leaves regrowth for perennial ryegrass and its productivity

The 2 years comparative research of the net gain tillers,leaves regrowth and cumulative yield for perennial ryegrass under different cutting intensities and cutting times.The results showed that the seasonal dynamics of net growth of leaves and net gain tillers coexisted mutual remedying characteristics.Cutting was not beneficial to tiller,all cutting treatments did not exist compensatory growth effect of tiller.The net gain tillers decreased with cutting times increasing,restraining tiller effect of higher cutting frequency strengthen year by year while lower cutting frequency weaken.The compensatory growth effect of leaves was remarkable at all cutting treatments.Cutting could simulative growth of leaves,increase net productivity,maintain suitable composition of mixed pasture and promote competition of perennial ryegrass.Net productivity increase mainly resulted from cutting simulated growth of leaves.Leaves net growth and net gain tillers of annul cumulating existed significant negative regression relationship ( R=-0.893, P <0.05).