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Chinese Journal of Applied Ecology ›› 2018, Vol. 29 ›› Issue (5): 1429-1436.doi: 10.13287/j.1001-9332.201805.027

• Special Features of Stable Isotope Ecology • Previous Articles     Next Articles

Nitrogen application technology in dwarfed apple trees.

CHEN Qian, DING Ning, PENG Ling, ZHU Zhan-ling, GE Shun-feng, JIANG Yuan-mao*   

  1. College of Horticulture Science and Enginee-ring, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai’an 271018, Shandong, China
  • Received:2017-08-02 Online:2018-05-18 Published:2018-05-18
  • Contact: *E-mail: ymjiang@sdau.edu.cn
  • Supported by:
    This work was supported by the Key Research and Development Program of China (2016YFD0201100), the Postdoctoral Science Foundation of Shandong Agricultural University (010-76513), the Earmarked Fund for the China Agriculture Research System (CARS-28), and the National Natural Science Foundation of China (31501713)

Abstract: 15N trace technique was used to explore the characteristics of 15N-urea absorption, utilization, loss and fruit quality of eight-year-old ‘Yanfu3’/M26/Malus hupehensis Rehd. seedlings. There were three different nitrogen fertilization treatments: one-time nitrogen application in spring (Ⅰ), two times nitrogen application (Ⅱ), the intensive technique of nitrogen application with several times application and reduction in amount (Ⅲ). The results showed that leaf area, chlorophyll content (SPAD value), photosynthetic rate (Pn), total N content of leaves and the total biomass per plant (except fruit), as well as the root-shoot ratio of treatment Ⅲ were obviously higher than those in the treatments of Ⅰ and Ⅱ. Treatment Ⅲ significantly increased the protective enzymes (SOD, POD and CAT) activities and decreased the malondialdehyde (MDA) content in leaves. Significant differences were found on the 15N derived from fertilizer (Ndff value) of different organs, with the fruit Ndff showing the highest, followed by the one-year-old branches, leaves and roots of the three treatments. The Ndff values of each organ were the highest in the treatment Ⅲ. At fruit maturity stage, total N content of plant in treatment Ⅲ was 93.0 mg·kg-1, which was obviously higher than that in the treatments Ⅰ (70.2 mg·kg-1) and Ⅱ (81.9 mg·kg-1). 15N nitrogen utilization ratio of treatment Ⅲ was 33.6%, which was obviously higher than that in the treatments Ⅰ (20.4%) and Ⅱ (26.0%). The 15N loss rate was 46.9% in treatment Ⅲ, being obviously lower than that in the treatments Ⅰ (56.5%) and Ⅱ (52.9%). There were significant differences of fruit mass, soluble solid, fruit firmness, soluble sugar content, titratable acids and sugar-acid ratio among different treatments, with the highest values in the treatment Ⅲ and the lowest values in treatment Ⅰ.