氮肥对荔枝幼苗生长及生理生化的影响

Effects of Nitrogen Fertilizer on Growth,Physiological and Biochemical Changes of Litchi Seedlings

以‘妃子笑’荔枝为材料,采用单因素试验设计方法,研究氮肥对荔枝幼苗生长及生理生化变化的影响,同时分析硝酸还原酶活力与可溶性总糖、可溶性蛋白质、硝酸盐、叶绿素含量等与植株生长之间的相关性,探讨荔枝幼苗时期优化的氮肥用量,为氮肥减量增效提供依据。结果表明:随施肥量增加,各形态指标和生理生化指标均呈现上升到下降的趋势,不同氮肥处理间,叶重、叶厚、枝条抽生量、新叶长出量、可溶性总糖含量、可溶性蛋白质含量、硝酸盐含量、硝酸还原酶活力有显著性差异,叶片健康状况直观差异明显;不同氮肥处理间,叶长、叶宽、树绝对增高量、树相对增高量、叶绿素含量均无显著差异。株施25.0 g处理和20.0 g处理在叶重、叶厚、枝条抽生量、新叶长出量、可溶性总糖含量、可溶性蛋白质含量、硝酸盐含量、硝酸还原酶活力、叶片健康状况均无显著差异。荔枝幼苗施肥量从每月株施25.0 g处理减少到20.0 g不会显著影响荔枝幼苗生长,每年667 m^2可减少氮肥1.32 kg。

In this experiment,the influence of nitrogen fertilizer on the growth,physiological and biochemical changes of seedlings of litchi cv.'Feizixiao,were studied by using the single—factor experimental design method.The correlation between plant growth and nitrate reductase activity,soluble total sugar,soluble protein,nitrate and chlorophyll content was analyzed,and the optimum amount of nitrogen fertilizer in the litchi seedling period were discussed to provide a basis for nitrogen fertilizer reduction and efficiency.The results showed that with the increase of fertilizer application,all the morphological,physiological and biochemical indexes showed a trend of increasing to decreasing.There were significant differences in leaf weight,leaf thickness,sprouting shoot number,new leaf growth,soluble total sugar content,soluble protein content,nitrate content,nitrate reductase,and leaf health status among all different nitrogen treatments.There were no significant differences in leaf length,leaf width,absolute tree height,relative tree height and chlorophyll content among different nitrogen treatments.There were no significant differences in leaf weight,leaf thickness,sprouting shoot number,new leaf growth,soluble total sugar content,soluble protein content,nitrate content,nitrate reductase activity and leaf health status when 25 g and 20 g nitrogen fertilizer per plant were applied.The reduction from 25 g nitrogen fertilizer per plant to 20 g in one month could not have significant effect on the growth of litchi seedlings,which can reduce nitrogen fertilizer by 1.32 kg per mu in one year.