Snowfall is a general natural phenomenon in winter-spring alternate season in northeast of China. Snow was melt with the increase of temperature, i.e. freezing-thawing alternations affects soil properties. Static chamber technique was used to monitor nitrous oxide (N2O) flux from black soils in a snowfall process. The fertilization treatments are none (CK), 150 kg N ha-1 (N1), 300 kg N ha-1 (N2) and 150 kg N ha-1 organic manure plus 150 kg N ha-1 chemical nitrogen fertilizer (M1N1). Before snowfall, there is insignificant difference in N2O emission from four treatments. After snowfall, N2O emission from CK, N1, N2 and M1N1 is 9.56, 9.16, 9.86, 9.91 mg N2O-N m-2 during 55-hour monitoring period, respectively (p<0.05). Snowmelt increase soil moisture content, which significantly stimulated the soil N2O emissions, meanwhile, freezing-thawing alternations influences N2O emission. The findings indicate that effect of snow on N2O emission should be considered separately, i.e. before and after snowfall.
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机译：降雪是中国东北冬春交替季节的普遍自然现象。雪随着温度的升高而融化，即冻融交替影响土壤性质。在降雪过程中，静态室技术用于监测来自黑土的一氧化二氮（N2O）通量。不施肥（CK），150 kg N ha-1（N1），300 kg N ha-1（N2）和150 kg N ha-1有机肥加上150 kg N ha-1化学氮肥（M1N1） 。在降雪之前，四种处理的N2O排放差异不大。降雪后，在55小时的监测期内，来自CK，N1，N2和M1N1的N2O排放分别为9.56、9.16、9.86、9.91 mg N2O-N m-2（p <0.05）。融雪增加了土壤的水分含量，这极大地刺激了土壤中N2O的排放，同时，冻融交替影响N2O的排放。调查结果表明，应考虑降雪对N2O排放的影响，即降雪前后。
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