地理学报 ›› 1999, Vol. 66 ›› Issue (6): 534-542.doi: 10.11821/xb199906007

• 论文 • 上一篇    下一篇

土壤氧化亚氮产生、排放及其影响因素

齐玉春, 董云社   

  1. 中国科学院地理研究所环境生物地球化学开放实验室,北京100101
  • 收稿日期:1999-07-02 修回日期:1999-08-16 出版日期:1999-11-15 发布日期:1999-11-15
  • 基金资助:
    国家自然科学基金面上基金项目(49671004);“九五”国家重大基础研究项目(95-22-02-01)

NitrousOxide Em issionsfrom Soiland Som eInfluence Factors

QIYu-chun, DONG Yun-she   

  1. Institute of Geography, Chinese Academy of Sciences, Beijing 100101
  • Received:1999-07-02 Revised:1999-08-16 Online:1999-11-15 Published:1999-11-15
  • Supported by:
    National Natural Science Foundation of China,No.49671004;No.95-22-02-01

摘要: 全球变化对人类生存环境的变化有着十分重要的影响。CO2、CH4、N2O 等气体排放量的增加是目前全球气候变化的主要诱因之一。因此, 对于温室气体的研究一直以来都是全球气候变化研究的热点, 其中, N2O 又以其增温潜势大、滞留大气时间长、破坏臭氧层等特点受到格外的关注。对于N2O 等温室气体源与汇、产生机制、影响因素以及相应减排措施的研究具有十分重要的现实意义。

关键词: 土壤, 氧化亚氮排放, 影响因素

Abstract: The globalchange isvery im portantto the change ofenvironm entofhum an be- ings. The increasing ofcarbon dioxide, m ethane, nitrousoxide and othergreenhousegas- es in atm osphereisoneofthem ain inducem entto theglobalclim atechange. Thestudy on greenhouse gaseshas alw ays been the topicofgeneralinterest. Am ong greenhousegases, interestin the increasing ofatm ospheric nitrous oxide (N2O) has been stim ulated by the understanding that this gas plays an im portant role in the chem istry ofthe stratosphere and the ozonelayerdestruction, itslong lifetim ein theatm osphereand asignificantinflu- ence on the earth therm albalance by the absorption oflong w ave infrared radiation (the greenhouse effect). Itisim portantto understand the sourcesand sinks, production m ech- anism s and m itigation m easuresofthe greenhouse gases. In this paper, we w illgenerally discuss aboutthe relevantstudy progressofN2O em ission in the recentyears. The scholars ofChina and othercountries have done num erous field experim ents and laboratory sim ulation studieson globaldistribution ofN2Osourcesand sinks, theseresults illustrated thatthe N2Om ainly com esfrom soil, w aterbody, biom ass burning, fossilfu- els com bustion and som e industrialprocesses etc., and the sink of N2O generally is thephotochem icalreaction in the stratosphere. Itism ore clearthatthenitrification and denitrification in soilare them ain N2Oem is- sion m echanism s. Thefactorsthatinfluencetheem ission ofN2Oin soilare sum m arized as follow s: (1) The application ofnitrogen fertilizer. The studiesshowed thatthe soiltreat- ed w ith the enduring effectfertilizerw illem ission less N2Othan those treated w ith the or- dinary effectfertilizer, and the application ofenduring effectfertilizercan also increasethe yield ofthe crop. (2) Soilm oisture. The m axim alem ission ofN2Oappears when the soil m oisture is 90% ~100% field capacity or 77% ~86% w ater-filled pore space. When the soilm oisture is below the saturation m oisture content, the nitrification is the m ain N2O production m echanism . When the soilm oisture is above the saturation m oisture content, the denification isthem ain N2Oproduction m echanism . Thesoilwillproducem ore N2Oin the transition from w etto dry. Thediffusion coefficientofgreenhouse gases in unsaturat- ed soilis2~4 orderofm agnitudebiggerthan thatin the saturated soil. (3) Soiltem pera- ture. 15~35℃is the favorable tem perature range forthe m icrobe activities ofthe nitrifi- cation, 5~75℃is favorable tem perature range for the m icrobe activity ofthe denitrifica- tion, the em ission flux ofN2O is norm aldistribution varying with the 5 cm daily average soiltem perature. (4) soilpH . The optim alpH is 7.0~8.0 forthedenification rate. (5) The contentofsoilorganic m atter. The m ineralization ofthe soilorganic m attercan pro- vide nitrogen (N) to soil. The favorable C/N ofsoilis 25~30∶1 to form N2O. (6) Soil porosity. When the soilporosity islow, such as betw een 10% and 12%, the denification willenhance, there are m arked increasing oftheconcentrations ofN2Oin the soilairafter their being com pacted by a tractor, but the flux of N2O from soilto air is lower in the com pacted soilthan thatin theuncom pacted soilbecauseofthe hindrance during the em is- sion process. (7) Plants them selves. The root grow th ofplant and the secretion of the rootcan change the soilcondition (chem icaland physicalcondition), som e crops such as soybean, m aize and rice them selves can also em ission N2O. w hat m ore, the illum inance and the cultivation ofthe fields etc. can also affectthe em ission ofthe N2O.

Key words: soil, nitrous oxide em issions, influence factors

中图分类号: 

  • S154.1