中国农业气象

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北方设施菜地土壤N2O排放通量日变化及最佳观测时间确定

徐 钰,刘兆辉,石 璟,魏建林,李国生,王 梅,江丽华   

  1. 山东省农业科学院农业资源与环境研究所/农业部黄淮海平原农业环境重点实验室/山东省农业面源污染防控重点 实验室,济南250100
  • 收稿日期:2016-03-25 出版日期:2016-10-20 发布日期:2016-10-12
  • 作者简介:徐钰(1981-),女,博士,研究方向为施肥技术与农业环境。E-mail:yuxu0221@163.com
  • 基金资助:
    公益性行业(农业)科研专项经费(201103039);山东省自然科学基金(ZR2013DQ023);山东省科技发展计划(2013GNC11204);“泰山学者”建设工程“农业面源污染防控”岗位资助

Diurnal Variation Characteristic of Nitrous Oxide from Greenhouse Vegetable Soil during Emission Peak and its Optimal Observation Duration

XU Yu, LIU Zhao-hui , SHI Jing, WEI Jian-lin, LI Guo-sheng, WANG Mei, JIANG Li-hua   

  1. Institute of Resource and Environment, Shandong Academy of Agricultural Sciences/Key Laboratory of Agro-Environment of Huang-Huai-Hai Plain, Ministry of Agriculture/Shandong Provincial Key Laboratory of Agricultural Non-Point Source Pollution Controland Prevention, Jinan 250100, China
  • Received:2016-03-25 Online:2016-10-20 Published:2016-10-12

摘要:

选择不同季节的4个N2O高排放通量日(2012年8月28日和12月27日、2013年3月14日和6月14日),利用静态暗箱-气相色谱法对设施菜地土壤N2O排放通量进行连续24h原位观测,以探讨其日变化特征,并确定1d内的最佳观测时间。结果表明,设施菜地施肥后(2012年12月27日除外)N2O排放通量呈明显的单峰型日变化规律,排放峰值一般出现在14:00左右,比气温峰值时间滞后约2h。同茬作物基肥后第13天与追肥后第2天相比,前者N2O日排放通量峰值和日均排放通量分别较后者高3.4~12.9倍和6.8~7.0倍。相关分析表明,4个典型日内,仅2012年12月27日的N2O排放通量与气温、3cm地温和10cm地温无显著相关,其它日均呈显著正相关。说明观测日土壤温度处于N2O形成适宜范围内,且气温日较差较大时,温度才是影响N2O排放通量日变化的主要因素。对24h内N2O排放通量的矫正分析结果表明,2012年8月28日和12月27日、2013年3月14日和6月14日分别在18:00-21:00、10:00-次日6:00、21:00、16:00-18:00的观测值,可以代表当天的N2O排放通量。若在其它时段采样,应进行有效的矫正处理,否则会导致对典型日N2O排放的估计偏高13.4%~240%或偏低13.1%~64.5%。

关键词: 设施菜地, N2O排放, 原位观测, 最佳观测时间, 矫正系数

Abstract:

The diurnal variation characteristics of N2O flux from a typical greenhouse vegetable soil during emission peak was investigated to obtain accurate N2O emission of greenhouse vegetable soil. After fertilizations, four typical days in four seasons were selected, which were 2012-08-28 (autumn), 2012-12-27 (winter), 2013-03-14 (spring) and 2013-06-14 (summer). The N2O fluxes were monitored by static chamber method and gas chromatographic technique continuously for 24 hours. The results showed that the significant diurnal variation and evident single-peak of N2O flux were found after fertilization (except for Dec. 27, 2012). The peak of N2O flux appeared at 14:00 pm and about 2 hours later than that of air temperature. The maximum and average value of N2O flux in 13th day after basal fertilization, compared with that on the second day after dressing, were 3.4 to 12.9 times and 6.8 to 7.0 times. There were highly significant (1%) or significant (5%) positive correlations between N2O flux(except for Dec. 27, 2012)and air temperature or soil temperature in 3cm and 10cm depth. It showed that the temperature might be the crucial factor in diurnal variation of N2O flux for the temperature is fate for N2O formation and the range of daily temperature difference is large enough. Based on the correct analysis, no correction is necessary for measurements carried out at 18:00-21:00, 10:00-6:00 (the next day), 21:00 and 16:00-18:00, which is recommended as the optimum time for Aug. 28, 2012; Dec. 27, 2012; Mar. 14, 2013 and Jun. 14, 2013, respectively. Correction coefficient is equal to the ratio of the daily average flux to the observing flux at different o’clock. It is recommended that the correction coefficient should be multiplied for the measured data based on other times; otherwise N2O emission might be overestimated by 13.4%-240% or underestimated by 13.1%-64.5%.

Key words: Greenhouse vegetable soil, Diurnal variation of N2O, In situ observation, Observation duration, Correction coefficient