Abstract: It is verified that plant is a new N₂Oemission source. The N₂Oemission rates of soybean, spring wheat and millet at different growing stages and that of spring wheat fertilized at several fertilization levels are measured by using open chamber method and C₂H₂ inhibitory technique. The results indicate that the N₂Oemission rates of these three kinds of plants increase gradually in early growing stages and reach the maxmium before and after blooming stage, and then decrease sharply. Significant difference in N₂Oemission rates among tested plants is found at the relative development stages. Of these plants, soybean shows the hightest N₂Oemission rate. Under different fertilization conditions, both growing status and N₂Oemission rate of spring wheat are different and the excess fertilization rasults in a higher N₂Oemission rate.

Key words: N₂O emission rate of plant, Growing stage, Fertilization