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草业学报 ›› 2016, Vol. 25 ›› Issue (2): 187-197.DOI: 10.11686/cyxb2015189

• 研究论文 • 上一篇    下一篇

紫色土区香根草不同径级的根系特征与培肥效应

谌芸, 何丙辉*, 练彩霞, 刘志鹏   

  1. 西南大学资源环境学院,三峡库区生态环境教育部重点实验室,重庆 400715
  • 收稿日期:2015-04-14 出版日期:2016-02-20 发布日期:2016-02-20
  • 通讯作者: E-mail:hebinghui@swu.edu.cn
  • 作者简介:谌芸(1981-),女,四川西昌人,副教授,博士。E-mail:sy22478@126.com
  • 基金资助:
    中央高校基本科研业务费专项(XDJK2015C170,XDJK2014C103,SWU113013),国家自然科学基金(41501288,41271291),国家科技支撑计划项目(2011BAD31B03)和西南大学教育教学改革研究项目(2013JY052)资助

Effects of Vetiveria zizanioides roots on soil properties in the Purple Soil Area of China and the role of different root diameter classes

CHEN Yun, HE Bing-Hui*, LIAN Cai-Xia, LIU Zhi-Peng   

  1. College of Resources and Environment, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Southwest University, Chongqing 400715, China
  • Received:2015-04-14 Online:2016-02-20 Published:2016-02-20

摘要: 为探讨水土保持先锋物种香根草的培肥效应及其与各径级根系指标间的关系,以裸地为对照,定期分010 cm,1020 cm,2030 cm土层采集土壤和根系样品,常规方法测定土壤有机质、氮、磷、钾的全量和速效养分,WinRHIZO(Pro.2004c)根系分析系统分10个径级测定根系参数(根长、根表面积和根体积)。结果表明:香根草的培肥效应主要体现在有机质上,且此效应随香根草定植时间的延长而增强,其次是全氮,而有效磷和速效钾则出现亏损;香根草小区土壤有机质、有效磷、全钾、速效钾均表现出明显的土壤养分表聚现象,在010 cm土层的含量显著大于其他土层的(P<0.05);0.00 mm<d≤2.00 mm(d为根系直径)是影响土壤有机质含量的主要根径范围,该范围内所有径级的根长密度/根表面积密度/根体积密度均与土壤有机质含量极显著正相关(P<0.01),尤其是径级0.00 mm<d≤0.50 mm,其次是径级1.50 mm<d≤2.00 mm;d=2.00 mm和d=4.50 mm是重要分界线,当0.00 mm<d≤2.00 mm时,香根草各径级的所有根系指标在土层间均表现出显著性差异且与土层深度极显著负相关,其中0.50 mm<d≤1.00 mm径级的相关系数值最大,当2.00 mm<d≤4.50 mm时土壤养分与所有径级的根系指标均无显著性相关;根重密度/根长密度/根表面积密度/根体积密度的最大值均出现在010 cm土层,且根长密度在年际间、土层间均表现出显著性差异。

Abstract: The aim of this study was to determine the effects of Vetiveria zizanioides plants and their roots on soil properties, and define the role of different root diameter classes. The research was conducted in the Purple Soil Area of China. The experiment compared bare control plots with plots planted in V. zizanioides. Soil and root samples were collected regularly from 0-10 cm, 10-20 cm, 20-30 cm soil layers. Contents of soil organic matter, total and available nitrogen, phosphorus, and potassium were measured by conventional methods. Roots were divided into 10 diameter classes measured by a Root Analysis System (WinRHIZO, Pro. 2004c). It was found that: 1) V. zizanioides substantially enhanced the accumulation of soil organic matter, the longer the planted time the greater the effect. V. zizanioides also promoted the accumulation of soil total nitrogen, but the effect was weak compared with organic matter. Both available phosphorus and potassium were depleted in all V. zizanioides plots. 2) The levels of organic matter, available phosphorus, total potassium and available potassium showed topsoil accumulation in all V. zizanioides plots; i.e. over time their levels in the 0-10 cm soil layer increased significantly more than in the 10-20 cm and 20-30 cm soil layers (P<0.05). 3) The root diameter range (d) 0.00 mm<d≤2.00 mm was dominant in affecting soil organic matter. root length density (RLD), Root surface area density (RSAD), and root volume density (RVD) of all diameter classes in this range were significantly and positively correlated with soil organic matter content (P<0.01), with the highest correlation being the 0.00 mm<d≤0.50 mm diameter range and the next highest being the 1.50 mm<d≤2.00 mm range. 4) Root diameters of d=2.00 mm and d=4.50 mm were important classification divisions. When 0.00 mm<d≤2.00 mm, RLD, RSAD, and RVD of all diameter classes showed significant differences between all soil layers and were significantly and negatively correlated with soil layer depth. The maximum correlation coefficient occurred in roots of the 0.50 mm<d≤1.00 mm diameter range. When 2.00 mm<d≤4.50 mm, all root parameters of all diameter classes were uncorrelated with any measured soil parameter. 5) The maximum RLD, RSAD, and RVD occurred in the 0-10 cm soil layer, and RLD differed significantly among all soil layers in the same year or between 2011 and 2013 in the same soil layer.