植物生态学报 ›› 2006, Vol. 30 ›› Issue (6): 976-982.DOI: 10.17521/cjpe.2006.0125

• 论文 • 上一篇    下一篇

黄土旱塬冬小麦返青期断根对根冠比、水分利用及产量的影响

马守臣1,2,3, 徐炳成1,2, 黄占斌1,2, 刘琳1,2, 张小红1,2, 刘文兆1,2, 李凤民1,2()   

  1. 1 中国科学院-水利部黄土高原土壤侵蚀与旱地农业国家重点实验室, 陕西杨凌 712100
    2 西北农林科技大学, 陕西杨凌 712100
    3 中国科学院研究生院, 北京 100049
  • 收稿日期:2005-09-12 接受日期:2006-03-23 出版日期:2005-09-12 发布日期:2006-11-30
  • 基金资助:
    中国科学院百人计划择优支持项目(C23013500)

EFFECTS OF PARTIAL ROOT EXCISION AT THE RE-GREENING STAGE OF WINTER WHEAT ON ROOT/SHOOT RATIO, YIELD AND WATER USE EFFICIENCY IN LOESS PLATEAU REGION, CHINA

MA Shou-Chen1,2,3, XU Bing-Cheng1,2, HUANG Zhan-Bin1,2, LIU Lin1,2, ZHANG Xiao-Hong1,2, LIU Wen-Zhao1,2, LI Feng-Min1,2()   

  1. 1 State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100, China
    2 Northwest Sci-Tech University of Agriculture and Forestry, Yangling, Shaanxi 712100, China
    3 Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2005-09-12 Accepted:2006-03-23 Online:2005-09-12 Published:2006-11-30

摘要:

采用适当的农艺措施来影响根系生长以提高作物水分利用效率是节水农业研究的一项重要内容。通过田间试验研究了旱作冬小麦‘长武135’(Triticum aestivum cv. Changwu135)返青期切断部分侧生根对根冠比、水分利用效率及产量的影响。与不断根处理相比,冬小麦切断部分侧根后,极显著地减少了表层的根量,花期时断根和不断根小麦在0~20 cm土层根量分别249.70和307.52 g·m-2,100 cm以上总根量分别为305.53和368.73 g·m-2。断根比不断根处理根呼吸速率下降了25.57%。断根也抑制了小麦的群体数量,断根和不断根处理单位面积的穗数分别为590.33和646.33 m-2,但断根显著增加了千粒重,断根和不断根分别为45.99和41.47 g,收获指数也有一定提高。断根对籽粒产量没有显著影响,但断根后土壤含水量显著增加,水分消耗减少。以生物量计算的水分利用效率和以产量计算的水分利用效率分别提高了32.52%和29.98%。因此,在旱地农业中,通过返青期人工断根措施削减根系降低根系对同化产物的消耗和减少耗水量来达到提高冬小麦水分利用效率的方法,是可行的。但今后还需对断根措施作进一步研究,以期实现产量和水分利用效率的同步提高。

关键词: 冬小麦, 断根, 根呼吸, 水分利用效率

Abstract:

Background and Aims It is important for water conservation that suitable agricultural measures are used to improve the water use efficiency (WUE) of crop production. Water-conserving irrigation has improved WUE of crops, but is difficult to practice in arid and semi-arid areas of Loess Plateau, especially those areas lacking water for irrigation. Therefore, water-conserving agriculture in these areas focuses on increasing the rainfall-use efficiency of crops. This study examines whether root-cutting can increase grain yield and WUE of winter wheat in rain-dependent farmland on Loess Plateau.

Methods The field experiment was conducted in 2004 and 2005 at the Changwu Experimental Station of the Chinese Academy of Sciences. The cultivar of winter wheat was `Changwu135' (Triticum aestivum cv. Changwu135), which is widely used by farmers in the region. Roots were partially cut off vertically to 13 cm depth along two sides, 2 cm away from the main stems at the re-greening stage (March 14, 2004). Soil water content was measured at 10 cm depth intervals at different developmental stages. Root respiration rate was measured at the flowering stage. Grain yield, aboveground biomass, spike number per unit area, grain weight and harvest index were measured at the maturity stage. We studied effects of partial root-cutting on root/shoot ratio (R/S), yield and WUE.

Key Results Partial root-cutting at the re-greening stage of winter wheat significantly decreased upper root biomass: root biomass to 20 cm soil depth at the flowering stage was 249.70 g·m-2 for root-cutting treatment and 307.52 g·m-2 for intact plants, and total root biomass was 305.53 g·m-2 for cutting treatment and 368.73 g·m-2 for intact plants. Root-cutting reduced root respiration rate by 25.57% compared with intact plants. Spike number was reduced to 590.33 m-2, compared to 646.33 m-2 for intact plants, but 1 000 kernel weight increased significantly after partial root-cutting (45.99 g compared to 41.47 g for intact plants), and harvest index also increased. Yield was little affected by root-cutting, but water consumption was greatly reduced. Biomass water use efficiency and yield water use efficiency were increased by 32.52% and 29.98%, respectively, compared with intact plants.

Conclusions Root-cutting reduced the root system of winter wheat, restraining population density which reduced water consumption and improved soil water content after anthesis. It is favorable to grain development in wheat. Root-cutting lowered root respiration rate and decreased the amount of dry matter consumed by the root system, which raised the proportion of dry matter allocated to aboveground organs. Dry weight of shoot was unaffected by root-cutting, but water consumption was greatly reduced. Therefore, WUE of winter wheat can be increased on dry lands by partial root-cutting at the re-greening stage. More study, especially on timing and intensity on root-cutting, is needed to synchronously increase grain yield and WUE of wheat.

Key words: Winter wheat, Root-cutting, Root respiration, Water use efficiency