地理科学进展 ›› 1998, Vol. 17 ›› Issue (4): 18-26.doi: 10.11820/dlkxjz.1998.04.003

• 论文 • 上一篇    下一篇

农田生态系统二氧化碳通量与群体水分利用率研究

杨晓光1, 于沪宁2   

  1. 1. 中国农业大学资环学院;
    2. 中国科学院地理研究所
  • 收稿日期:1998-08-01 出版日期:1998-12-24 发布日期:1998-12-24
  • 作者简介:杨晓光,女,中国农业大学资环学院讲师,在职博士生。主要从事农田光能利用和水分利用等方面的研究。
  • 基金资助:

    国家自然科学基金,地球科学部基金项目

A STUDY ON THE CO 2 FLUX DENSITY ANDTHE WATER USE EFFICIENCY OF CROP COMMUNITY IN A FIELD ECOSYSTEM

Yang Xiaoguang1, Yu Huning2   

  1. 1. China Agricultural University, Beijing 100094;
    2. Institute of Geography, Chinese Academy of Sciences, Beijing\ 100101
  • Received:1998-08-01 Online:1998-12-24 Published:1998-12-24

摘要: 本文利用二氧化碳分析系统,配合波文比装置,测定了夏玉米农田群体二氧化碳浓度差及农田小气候特征,并计算了农田冠层瞬时的二氧化碳通量和群体水分利用率。结果表明,夏玉米群体二氧化碳通量、二氧化碳浓度差及群体水分利用率存在明显的日、季节变化规律。其中水分利用率呈“L”型曲线,上午8时左右达到一天的峰值。拔节后随着作物生长发育水分利用率逐渐增大,灌浆后期由于群体光合能力下降、呼吸消耗增强而逐步下降。太阳总辐射、二氧化碳浓度、空气饱和差及土壤水分等环境因素以不同机制及过程影响水分利用率。在生产实际中,可通过秸秆覆盖、喷灌等措施降低蒸腾驱动势,提高水分利用率。

关键词: 二氧化碳通量, 群体水分利用率, 蒸腾驱动势

Abstract: The CO 2 flux concentration gradient and microclimate characteristics of a summer corn community were measured with an infrared CO 2 analysis system and a Bowen ratio device. The instantaneous CO 2 flux density and the water use efficiency of the corn canopy were calculated. The result showed that the CO 2 flux and CO 2 concentration gradient as well as the water use efficiency of the summer corn community had distinct daily and seasonal change patterns. The daily change of the water use efficiency was described in a ‘L’type curve with a peak value around 8 a.m. in the morning. Before grain filling, the water use efficiency increased as the corn grew, while it decreased after grain filling because of the decrease of photosynthetic ability of the corn community and the increase of respiration consumption. The water use efficiency was affected by the factors such as global radiation and CO 2 concentration and air saturation deficit etc. Therefore, in agricultural practice, the water use efficiency of the corn community could be raised by means of straw cover and sprinkling irrigation to reduce drive potential of transpiration.

Key words: CO 2 flux density, forcing functions of evapotranspiration, water use efficiency of crop community

中图分类号: 

  • S181