| China is the country which uses the most nitrogen fertilizers in the world. In 2004 the amount of the nitrogen fertilizers used by China came to 32 million tons, while the fertilizer-N use efficiency was as low as 30%-35%. The nitrogen from plant is one of the causes of the low fertilizer-N use efficiency as well as the loss from croplands. Many study found that plant can emit ammonia via its stomata in its growth stage. Ammonia emission from plant is the most uncertain factor in the complication of a global ammonia budget, for vegetation can act as both source and sink for atmospheric ammonia. Thus, the study on ammonia volatilization of rice shoot has important significance for improve fertilizer-N use efficiency and atmospheric environment.The close chamber method was used to study the difference between the ammonia volatilization from different rice genotypes, the difference between the ammonia volatilization from rice genotypes and the relation between the ammonia volatilization from rice shoot, the nitrogen use efficiency and the factors including intrinsic factors and extrinsic factors which may affect the ammonia The purpose is to screen the rice genotypes with low ammonia volatilization, improve the fertilizer-N use efficiency, reduce the loss of nitrogen fertilizers and reduce the pollution caused by ammonia volatilization.The results showed that the ammonia volatilization in the day was higher than that at night for the difference of temperature and illumination. The largest amount of diurnal ammonia volatilization came forth at anthesis and it varied with rice genotypes. This suggested that anthesis was the crucial stage of the ammonia volatilization from rice shoot in the whole growth stage.Significant variance could be observed in the total amount of ammonia volatilization from shoots of these 4 genotypes in late growth stage (F=4.47, P<0.05) ,while the amount of ammonia volatilization had no correlation with the shoot dry weight and the leaves dry...
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