脲胺氮肥对太湖地区稻田氨挥发及氮肥利用率的影响

Effects of Urea-ammonium Mixed Nitrogen Fertilizer on Ammonia Volatilization and Nitrogen Use Efficiency in Paddy Field of Taihu Lake Region

采用田间小区试验，以普通尿素和氯化铵为对照，研究脲胺氮肥对太湖地区稻田氨挥发及氮肥利用率的影响。结果表明：氮肥施入后，氨挥发损失主要发生在施肥后5 - 7天内，氨挥发损失量与田面水 NH4＋ -N浓度呈线性正相关关系。不同氮肥的氨挥发损失差异显著（P〈0.05），脲胺氮肥的氨挥发损失分别比普通尿素和氯化铵减少了2.71和6.41 kg/hm^2，并且该氮肥对水稻有增产的趋势，氮肥利用率分别比普通尿素和氯化铵显著提高了10.43% 和10.64%。此外，综合考虑经济和环境效益，该氮肥净收益高于尿素和氯化铵。因此，脲胺氮肥值得在太湖地区推广。

A field plot experiment was conducted in Taihu Lake region to investigate the effects of urea-ammonium mixed nitrogen fertilizer versus an individual form of urea or ammonium chloride on ammonia volatilization （NH3）, rice yield and nitrogen use efficiency （NUE） in rice cropping system. Regardless of types of fertilizers, the flux pulse of NH3 volatilization mainly appeared after N fertilizer applications with a duration of 5–7 days, and its value linearly increased with the increasing ammonium concentrations in the surface water of paddy field. Compared to urea or ammonium chloride, urea-ammonium mixed nitrogen fertilizer significantly reduced the NH3 emission by 2.71 and 6.41 kg/hm^2, respectively （P〈0.05）. Urea-ammonium mixed nitrogen fertilizer also led to the greater rice yields and higher economic benefit than single application of urea or ammonium chloride. The NUE of urea-ammonium mixed nitrogen fertilizer was increased by 10.43% and 10.64% compared with single application of urea and ammonium chloride, respectively. Taking account of NH3 emission, yield and NUE, the urea-ammonium mixed nitrogen fertilizer should be a promising nitrogen for increasing economic benefits and decreasing the environment risk in Taihu lake region.