Influence Of Nitrogen And Phosphorus Fertilizers On Soil N₂O Emissions In Chinese Fir Plantation Ecosystem

N2O is an important member of the greenhouse gases, and is a important factorcausing global warming. Forest is an important source of atmospheric N2O, in ourcountry, the area of subtropical Chinese fir plantation is big, and people may havesome fertilization activity in forest management, so explore the N2O emission on thesubtropical Chinese fir plantation soil under these fertilization activities is veryimportant. In this study, we choose the Subtropical Chinese fir plantation in the shixiforestry station of qianyanzhou experimental station of CAS as the research object,and using the method of static chamber-gas chromatograph techniques. To study thesoil N2O emissions under the6kinds of fertilizer treatments (blank control (CK),low nitrogen (N1), high nitrogen (N2), add phosphorus (P), low nitrogen andphosphorus (N1P) and high nitrogen and phosphorus (N2P)). The main conclusionsare as follows.Under different fertilizer treatments, the Chinese fir plantation soil N2Oemissions have some differences. CK, N1, N2, P, N1P and N2P average soil N2Oflux of2013were10.49±0.73、13.13±1.10、22.98±2.82、13.28±1.24、12.55±0.36and28.15±3.58μg·m-2·h-1. Nitrogen fertilizer could increase soil N2O emissions,especially high nitrogen treatment can significantly increase the soil N2O emissions(P <0.05). Phosphorus fertilizer also could increase soil N2O emission. Nitrogen andphosphorus mix fertilizer could increase soil N2O emission too. Low nitrogen andphosphorus mix fertilizer compared with low nitrogen fertilizer has the trend ofreduce soil N2O emission, high nitrogen and phosphorus mix fertilizer in contrast tothe high nitrogen fertilizer has the trend of increase soil N2O emission. The influencethat nitrogen and phosphorus fertilizer to the soil N2O emission and to the NO3--Nand NH4+-N content in the soil is the same. Under different fertilizer treatments, The soil N2O emissions in Chinese firplantation have the same trend of seasonal change. But in the different season theN2O emission have large gap. accounted for more than60%in summer, thedifference in spring, autumn and winter is small, which is lowest in winter.Fertilization can only change the extent of the soil N2O emission change on the basisof season change. CK, N1, N2, P, N1P and N2P total soil N2O emissions of2013were0.92、1.14、1.91、1.17、1.12and2.43kg·hm-2.Under different fertilizer treatments, there is a significant correlation betweensoil N2O emission and soil temperature (P <0.05), no matter in wet or dry season orthroughout the year. But there isn’t a significant correlation between soil N2Oemission and soil moisture. Soil N2O emission was significantly affected by soiltemperature. And the relationship between them is affected by the soil moistureand fertilizer. The correlation between soil temperature and soil N2O emission inhigh soil moisture (wet season) is more significantly than the dry season. Therelationship between soil temperature and soil N2O emissions has large disturbanceunder high nitrogen fertilizer treatment.