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草业学报 ›› 2013, Vol. 22 ›› Issue (4): 319-326.DOI: 10.11686/cyxb20130437

• 研究简报 • 上一篇    下一篇

氮肥、刈割强度对桂牧1号杂交象草光合特性的影响

梁志霞1,2,3,杜虎1,3,彭晚霞1,3,曾馥平1,3,杨钙仁2,谭秋锦1,2,3,宋同清1,3*   

  1. 1.中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,湖南 长沙 410125;
    2.广西大学林学院,广西 南宁 530004;
    3.中国科学院环江喀斯特生态系统观测研究站,广西 环江 547100
  • 出版日期:2013-08-20 发布日期:2013-08-20
  • 通讯作者: E-mail:songtongq@isa.ac.cn
  • 作者简介:梁志霞(1987-),女,广西玉林人,硕士。E-mail:littlelittlesea@163.com
  • 基金资助:
    中国科学院西部行动计划项目(KZCX2-XB3-10),国家科技支撑计划(2011BAC09B02),中国科学院战略性先导科技专项(XDA05050205, XDA05070404),国家自然科学基金项目(No. 31000224, 31070425, U1033004)和中国科学院“西部之光”人才培养计划资助。

Effect of nitrogen fertilization and cutting intensity on the photosynthetic
characteristics of Pennisetum purpureum cv. Guimu No.1

LIANG Zhi-xia1,2,3, DU Hu1,3, PENG Wan-xia1,3, ZENG Fu-ping1,3,
YANG Gai-ren2, TAN Qiu-jin1,2,3, SONG Tong-qing1,3   

  1. 1.Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China;
    2.Forestry College of Guangxi University, Nanning 530004, China;
    3.Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjian 547100, China
  • Online:2013-08-20 Published:2013-08-20

摘要: 采用两因素的随机区组设计,研究了氮肥(250 kg/hm2、不施氮肥)、不同刈割强度(即刈割时离地面5,20和50 cm)对桂牧1号杂交象草光合特性的影响。结果表明,6个处理叶片净光合速率日变化曲线均为双峰曲线,但随着刈割强度的增加,光合速率先升高后降低,且在施氮肥的情况下,光合“午休”明显减弱。施氮肥能显著增加桂牧1号杂交象草的叶绿素含量和最大净光合速率。在施加氮肥的情况下,随着刈割强度的增加,叶片表观量子效率有增加的趋势,羧化效率先增大后降低,光补偿点、光呼吸速率和暗呼吸速率则呈现相反的变化趋势;而在不施氮肥的情况下,随着刈割强度增加,表观量子效率、光补偿点、羧化效率、光呼吸速率和暗呼吸速率均呈现先减少后增加的趋势。这些试验结果表明,氮肥、刈割强度均对桂牧1号杂交象草光合特性产生了一定的影响,在中强度刈割条件下,对桂牧1号施用250 kg/hm2氮肥,可以显著提高其光合能力。

Abstract: The effects of nitrogen fertilization (250 kg/ha and unfertilized) and cutting intensities (5 cm, 20 cm, or 50 cm above ground level) on the photosynthetic characteristics of Guimu No.1 (Pennisetum purpureum cv. Guimu No.1) were studied in a two factor randomized experiment. All the diurnal variations of net photosynthetic rate (Pn) in the six treatments followed a bimodal curve distribution. However, with an increase of cutting intensities, the Pn initially rose but then declined and with nitrogen fertilization, the noon break phenomenon of photosynthesis was reduced. Nitrogen fertilization increased chlorophyll content and the maximum net photosynthetic rate (Amax). With an increase of cutting intensities in the N-fertilization treatments, apparent quantum efficiency (AQE) increased, while carboxylation efficiency (CE) initially increased but finally declined; the reverse was true for the light compensation point (LCP), photorespiratory rate (Rp) and dark respiration rate (Rd). With an increase of cutting intensities in treatments with no N-fertilization, AQE, LCP, CE, Rp and Rd all declined initially but then increased. This indicated that both nitrogen fertilization and cutting intensity have some influence on the photosynthetic characteristics of Guimu No.1 with the best effect from a combination of medium-intensity cutting and 250 kg/ha nitrogen.

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