The N2O flux increased significantly during the thawing and ranged from 0.

The N2O flux characteristics and relationships between fluxes and environmental factors,such as temperatures,moistures etc,were also analyzed.

Soil temperature was the important environmental factor affecting the seasonal variation of N2O flux.

The N2O flux was higher in wheat field than in fallowed field, and decreased in the order of film-mulching>routine treatment>single phosphorus fertilization.

To fractionate the contribution of plant to N2O emission from soil-plant system,the N2O emissions from soybean,soil and soil-plant system were measured by closed chamber method under field condition.

N2O emission fluxes were measured using the technique of closed opaque chamber and gas chromatography system,in a field experiment carried out during three growing seasons in 2003-2005 on a tract of Calamagrostis angustifolia meadow and Carex lasiocarpa marsh.

[Objective] The aim was to study the effect of soil texture and environmental factors on N2O emission flux.

Soil N2O flux was measured for a whole year in winter wheat-summer maize rotation system in the North China Plain to determine its sources and changes in the soil,by using close chamber method.