施氮对杉木幼苗生长情况及养分分配的影响

Effects of N Application on Nutrient Balance of Chinese fir Seedlings

[目的]对不同施氮水平(高氮、低氮、对照)下杉木幼苗的生长情况以及养分分配进行研究。[方法]测定杉木幼苗的胸径、树高以及叶片、茎、根氮含量。[结果](1)不论是施氮1个月后还是施氮5个月后,各处理下杉木幼苗的胸径和树高大小比为:高氮处理>低氮处理>对照处理。同一时间段下,杉木幼苗的胸径大小比为:高氮处理>低氮处理>对照处理,树高的变化趋势与胸径的一致。(2)同一处理水平下,施氮5个月后各个植物器官氮含量均大于施氮1个月后;同一时间段下,相比于对照CK,高氮和低氮处理都能提高杉木幼苗各组织器官氮含量,如施氮5个月后,叶片高氮和低氮相对于对照分别增加了68.05%,17.71%;茎则是3.52%,1.83%;根则是167.01%,49.83%,其中叶片中氮含量增幅最大。[结论]施氮会明显增加杉木幼苗各个器官氮含量,影响植物养分分配及平衡。

[Objective]Through control experiment,the Chinese fir seedling growth and nutrient allocation under the different nitrogen levels（high nitrogen and low nitrogen,control） was studied.[Method]Diameter at breast height（DBH）,tree height and leaf nitrogen content of Chinese fir seedlings were determined.[Result]The results show that：（1） whether add nitrogen after 1 month or after 5 months,diameter at breast height（DBH） and tree height size of Chinese fir seedlings is： high nitrogen 〉 low nitrogen 〉 control.Under the same time,diameter at breast height size（DBH） of Chinese fir seedlings is ： high nitrogen 〉 low nitrogen 〉 control,the change trend of tree height consistent with DBH.（2） under the same treatment,added nitrogen after five months the N content of plant organs were greater than 1 months.Under the same time,compared with CK,high nitrogen and low nitrogen treatment can improve the Chinese fir seedlings organs N content,such as added nitrogen after 5 months,N content leaves under HN and HN relative to the CK respectively increased by 68.05%,17.71%; stems are3.52%,1.83%; root are 167.01%,49.83%,the N content in the leaves rise fastest,N content in stem growth is minimal.[Conclusion]The results of the study shows that nitrogen can significantly increases the Chinese fir seedlings N content in various organs,affects plant nutrient allocation and balance.