Abstract: Taking Sorghum sudanense as the research object,the present study adopted cutting and fertilization to investigate its growth and physiological and biochemical changes and unveil the underlying reason of its compensatory growth in order to provide reference for introduction and widespread cultivation of Sorghum sudanense. The study results indicated cutting significantly affected the specific leaf area of Sorghum sudanense (P<0.05). Higher cutting frequency led to increasingly larger specific leaf area,significantly lower plant height,higher tiller number,apparently lower contents of proline and malondialdehyde within the plant,and higher compensation index. It suggested cutting promote the compensatory growth of Sorghum sudanense. Fertilization didn't affect the specific leaf area,tiller number and malondialdehyde content (P>0.05) of the plant. After fertilizer applied,relative conductance declined first and then increased with increasing fertilization concentration. Fertilization increased the plant height of Sorghum sudanense. Fertilization and cutting interacted with each other in an obvious way. Fertilization promoted the compensatory growth of Sorghum sudanense through vegetative growth,but its effect had a time lag. It neither neutralized the negative effect of cutting nor boosted the compensatory growth resulting from cutting in the short term. Under fertilization and cutting,Sorghum sudanense achieved over-compensatory growth by changing its biomass allocation performance. A reasonable combination of fertilization and cutting could produce higher yield.

Key words: Fertilization, Clipping, Sorghum sudanense, Compensatory growth

摘要： 本研究以苏丹草（Sorghum sudanense）为研究对象，通过刈割和施肥处理，研究苏丹草生长情况及生理生化变化，初步探索苏丹草补偿生长原因，为苏丹草引种和种植提供参考。研究结果表明，刈割显著影响（P<0.05）苏丹草比叶面积大小，随着刈割次数的增加，比叶面积逐渐增大，株高显著（P<0.05）降低，分蘖数增加，植株内脯氨酸和丙二醛含量显著（P<0.05）降低，补偿指数增大，说明刈割能促进苏丹草的补偿生长。施肥对苏丹草的比叶面积、分蘖数、丙二醛含量影响差异不显著（P>0.05））；施肥后，相对电导率随着施肥浓度的增加先降低后上升，施肥和刈割具有显著的交互作用，施肥对苏丹草的补偿生长主要表现在促进营养生长方面，但施肥对补偿生长的作用具有时滞性，施肥在短期内不能抵消刈割的负面影响，也不能增加刈割造成的补偿生长量。施肥和刈割条件下，苏丹草发生超补偿性生长是通过改变植株的生物量分配模式来实现的。施肥和刈割处理合理组合可获得更大产草量。

关键词: 施肥, 刈割, 苏丹草, 补偿生长