• 研究报告 •

### 指数施肥对美国山核桃幼苗生物量及氮积累的影响

1. 1南京林业大学林学院南方现代林业协同创新中心， 南京 210037；2生态环境部南京环境科学研究所， 南京 210042）
• 出版日期:2018-10-10 发布日期:2018-10-10

### Effects of exponential fertilization on biomass and nitrogen accumulation of Carya illinoensis seedlings.

WANG Yi-ming1,2, LI Rui-rui1, ZHANG Hui2, JU Chang-hua2, PEI Wen-ming2, HU Fei1, WAN Fu-xu1*

1. (1Co-Innovation Centre for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China; 2Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China).
• Online:2018-10-10 Published:2018-10-10

Abstract: An exponential fertilization experiment was conducted with six N application levels (0 (CK), 100, 200, 400, 600, 800 mg·seedling-1) to examine the effects of N application levels on the growth and N accumulation of pecan (Carya illinoensis) seedlings. The objective of this study was to reveal the N demand and determine the optimal N application amount for pecan seedlings. Results showed that the stem biomass, leaf biomass, and total biomass of pecan seedlings increased as fertilization levels increased from 0 to 600 mg·seedling-1 and then decreased with the levels increased from 600 to 800 mg·seedling-1. The maximum values of these three variables were 2.30, 4.39 and 9.33 g·seedling-1, being 2.30, 4.99 and 2.17 times as high as that of the CK respectively. Root biomass decreased with the increases of N supply. For exponential fertilization treatments, the N concentration increased by 79%-640% in roots, 101%-352% in stems, and 43%-103% in leaves with N content increasing 184%-666% in roots, 240%-935% in stems, and 402%-823% in leaves. The N content and total biomass of pecan seedlings increased as the N fertilization increased from 0 to 600 mg·seedling-1 and then decreased with the fertilization levels  from 600 to 800 mg·seedling-1. The N concentration of pecan seedlings increased with the increases of N supply. We concluded that 600 mg·seedling-1 would be the optimal N application level for pecan seedlings in greenhouse.