节水灌溉稻田氨挥发损失及影响因素

为了揭示节水灌溉稻田氨挥发特征，开展了不同灌溉模式稻田氨挥发损失的田间试验，分析了节水灌溉稻田氨挥发速率季节变化规律与稻季氨挥发损失量，以及稻田氨挥发速率与影响因素之间的相互关系。结果表明，控制灌溉稻田氨挥发速率与淹水灌溉稻田变化规律基本一致，且在分蘖肥引起氨挥发出现峰值后的大部分时间里都要低于淹水灌溉；控制灌溉与淹水灌溉稻田稻季氨挥发损失总量（以纯氮计）分别为125.27 kg/hm2和145.64 kg/hm2，分别占稻季施氮量的31.06%和36.11%。除了受施肥影响外，稻田氨挥发还与田面水（表层土壤水）铵态氮浓度、空气温度、风速、日照时数及空气湿度等有密切关系。与淹水灌溉相比，控制灌溉减少了稻田氨挥发损失。

Ammonia volatilization and its influence factors of paddy field under water-saving irrigation

In order to study the characteristics of ammonia volatilization from paddy field under water-saving irrigation, ammonia volatilization under different irrigation techniques were measured through field experiment. Variations of ammonia volatilization rate and volatilization amount of paddy field during rice growing season were analyzed, as well as the relationships between ammonia volatilization rate and its influence factors. The results showed that the ammonia volatilization rate during rice growing season under controlled irrigation varied with the same pattern as that under flooding irrigation, and was lower than that under flooding irrigation in the most time after reaching the peak value of ammonia volatilization induced by tiller fertilizer. Volatilization amount during rice growing season was 125.27 kg/hm2 under controlled irrigation, and it was 145.64 kg/hm2 under flooding irrigation, account for 32.06% and 36.11% of the applied N respectively. In addition to fertilization, the ammonia volatilization from paddy field had close relationship with NH4+-N concentration in surface water or surface soil water, air temperature, wind speed, day light hours and the air humidity. Compared with flooding irrigation technique, controlled irrigation can reduce ammonia volatilization.