[Ammonia volatilization loss of nitrogen fertilizer from rice field and wet deposition of atmospheric nitrogen in rice growing season].

Plot and field experiments showed that the NH3 volatilization loss from rice field reached its maximum in 1-3 days after N-fertilization, which was affected by the local climate conditions (e.g., sun illumination, temperature, humidity, wind speed, and rainfall), fertilization time, and ammonium concentration in surface water of the rice field. The wet deposition of atmospheric nitrogen was correlated with the application rate of N fertilizer and the rainfall. The amount of nitrogen brought into soil or surface water by the wet deposition in rice growing season reached 7.5 kg.hm-2. The percent of NH4(+)-N in the wet deposition was about 39.8%-73.2%, with an average of 55.5%. There was a significant correlation of total ammonia volatilization loss with the average concentration of NH4(+)-N in wet deposition and total amount of wet deposition in rice growing season.