• 论文与研究报告 •

### 秋季施肥对毛白杨苗木质量、造林效果和养分回流的影响

1. 1. 北京林业大学省部共建森林培育与保护教育部重点实验室 北京 100083
2. 城乡生态环境北京实验室 北京 100083
3. 北京市黄垡苗圃 北京 102601
• 收稿日期:2020-06-05 出版日期:2021-07-25 发布日期:2021-09-02
• 通讯作者: 李国雷
• 基金资助:
国家重点研发专项"白杨工业资源材高效培育技术研究"(2016YFD0600403)

### Effects of Autum Fertilization on Quality, Field Performance and Nutrient Resorption of Populus tomentosa Seedling

Miaomiao Wang1,Yong Liu1,Guolei Li1,2,*,Yuxin Peng3,Chunhe Liu3,Jiansong Zhao3,Shuhong Wang3,Biao Dong1,Changwei Wang1,Ruirui Zhao1

1. 1. Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University Beijing 100083
2. Beijing Laboratory of Urban and Rural Ecological Environment Beijing 100083
3. Beijing Huangfa Nursery Beijing 102601
• Received:2020-06-05 Online:2021-07-25 Published:2021-09-02
• Contact: Guolei Li

Abstract:

Objective: In the present study, we explored optimal fall fertilization regime by investigating seedling quality and field performance of Populus tomentosa in order to provide a theoretical basis for nursery accurate fertilization management. Furthermore, we examined the inner-mechanism of growth and nutrient resorption in field. Method: In this study, triploid P. tomentosa was used as experimental materials. Fertilization was carried out in fall after the formation of terminal buds, once a week for consecutive six weeks (from September 2 to October 7). A completely randomized block design with one factor was used to set four fertilization levels: 0, 5, 10, 20 g fertilizer per seedling totally (a water-soluble commercial fertilizer: 20%N + 20%P2O5 + 20%K2O + TE). Seedling height, diameter and stem biomass (or stem volume) were measured at the beginning and end of each growing season. We also determined nutrient concentration and non-structural carbohydrate (NSC) levels in stems and roots in nursery, as well as nutrient concentration in green and senesced leaves in field. Result: 1) In nursery, fall fertilization had little effect on seedling growth, but significantly increased N and NSC accumulation, especially in roots. The N concentration in stems and roots increased by 2.4%-12.0%, 17.4%-48.1%, respectively, and the root starch concentration increased by 17.9%-34.5%. Fall fertilization with N, P and K was mainly enhanced N storage but no significant effect on P or K storage, indicating the preference for N utilization. 2) In field, the growth of height, diameter and stem volume reached the maximum when the fertilizer amount was 10 g per seedling (increased by 40.0%, 80.4%and 85.3% respectively compared with the control), fully exhibiting the effects of fall fertilization in the nursery. When fertilization rate increased to 20 g per seedling, the seedling growth was inhibited and the survival rate the minimum of (63.3%) after afforestation. The result demonstrated that it is important to optimize fall fertilization rate. 3) Furthermore, the enhance of growth (10 g fertilizer per seedling) increased N resorption efficiency (71%) and decreased N leaching loss from deciduous leaves (56.4%). 4) Our results also showed that the changes of nutrient resorption were associated with shifts of multi-elements in leaves rather than single-element. Nitrogen resorption was negatively related to N and K concentration in senesced leaves, while positively related to P concentration in green and senesced leaves. Phosphorus resorption was positively related to N concentration in green leaves. Conclusion: N storage, NSC levels with field performance of seedlings are important indicators to evaluate the effect of fall fertilization. Infield, the increments of growth increase N resorption from leaves and sequence, decrease N leaching. It is paramount to optimize fall fertilization rate, however it is particularly important to determine the reasonable amount of fertilization in fall. Nutrient storage, NSC accumulation and field performance of triploid P. tomentosa seedlings are benefit when fertilization rate is 10 g fertilizer per seedling, but when fertilization rate is 20 g fertilizer per seedling, it has a negative effect.