【摘要】 为探明下辽河平原几种旱作农田N2O排放通量及相关因素的影响,采用静态箱(暗箱)/气相色谱法对东北地区3种典型的旱地作物(玉米、大豆和春小麦)的N2O排放进行了原位测量,同时测量了土壤湿度等相关影响因子。结果表明,3种旱田作物的N2O排放在其各自生长季内均表现出比较明显的季节变化规律。在整个生长季观测中,常规处理N2O排放通量变化范围和平均通量分别为:玉米田-26.2～822.1μg·m-2·h-1,平均通量110.3μg·m-2·h-1;大豆田-96.8～281.0μg·m-2·h-1,平均通量66.0μg·m-2·h-1;春小麦田-27.1～183.1μg·m-2·h-1,平均通量46.3μg·m-2·h-1。研究还表明,土壤湿度是制约旱田N2O释放的关键因素,在土壤湿度较低时,施N肥并不会增加N2O的排放量。从作物的整个生长季来看,施N肥处理比未施N肥处理的N2O排放量要高,具体表现在玉米田和春小麦田常规处理N2O排放总量分别是无N处理的3.88倍、1.10倍。更多还原

【Abstract】 The N2O emission fluxes and seasonal variations from maize, soybean and spring wheat fields under different treatments were measured by static closed chamber-gas chromatograph. In order to find the relationship between the N2O emission and the impact factors, the temperature and soil moisture etc, were observed in the meanwhile. The results showed that there were significant seasonal variations of N2O emissions between different treatments and crops. The N2O emission flux of normal treatment in maize field ranged from -26.2 to 822.1μg N2O·m-2·h-1, with the mean of 110.3 μg N2O·m-2·h-1, much higher than the other two crops. The N2O emission flux ranged from -96.8 to 281.0 μg N2O·m-2·h-1 and -27.1 to 183.1 μg N2O·m-2·h-1, with the averages of 66.0 and 46.3 μg N2O·m-2·h-1 respectively in soybean field and spring wheat field. The soil moisture was the primary factor that influenced N2O emission in dryland fields. Generally, there was a remarkable increase of N2O emission when the soil moisture increased rapidly. At the low soil moisture, the nitrogen fertilizer could not increase the N2O emission. During the growing season, the N2O flux in the nitrogen-fertilized treatment was higher than the treatment without nitrogen fertilizer. The total N2O emission flux in the normal treatment was 3.88 times and 1.10 times of that in the no nitrogen-fertilized treatment in the maize field and the spring wheat field, respectively.更多还原