Ammonia volatilization was a major path of nitrogen losses in Paddy field. In order to evaluate the effects of different nitrogen schemes on ammonia volatilization and nitrogen use efficiency in Jianghuai hilly region

a field experiment by the closed airflow chamber method was conducted. The results showed that the ammonia volatilization loss ratio was the highest at tillering stage

followed by basal stage

and finally heading stage. Compared with the conventional fertilization

the ammonia volatilization loss amount and the ratio under the application of slow-release urea combined with common urea were decreased by 26.23% and 4.52%

respectively

while the nitrogen use efficiency increased by 6.07%. Ammonia volatilization loss was positive correlated with ammonium nitrogen concentration in the surface water. Therefore

the application of slow-release urea combined with common urea can not only reduce ammonia volatilization loss

but also obtain higher economic benefit

which is suitable to be recommended in Jianghuai hilly region.