Abstract:With the increasing chemical fertilizers application and serious soil degradation, the greenhouse gas emissions from agriculture field have been also concerned. The experiment combined organic nitrogen and inorganic nitrogen in order to study N2O emissions in dry tobacco field. There were 6 treatments:CK0 (no fertilizer), CK1 (100% inorganic nitrogen), T1 (50% inorganic nitrogen/50% cake fertilizer nitrogen), T2 (50% inorganic nitrogen/50% sheep manure nitrogen), T3 (25% inorganic nitrogen/75% cake fertilizer nitrogen), T4 (25% inorganic nitrogen/75% sheep manure nitrogen). Totally 45 kg/hm2 nitrogen was applied for each treatment. With in 142 days from applying basic fertilizer, the N2O emission flux, NO3-, NH4+, 0—5 cm soil temperature and moisture content were analyzed. The results showed that:(1) The N2O emission flux of the soil reached a high flux after 3~7 days of basic fertilization. The inorganic fertilizer and the combined fertilizer of inorganic and organic for the first high flux were lasting about 20 days and 9 days respectively. The N2O emission flux of the soil reached a high flux one more time after 3 days of the second fertilization, and lasted 9 days. During the tobacco growing, soil N2O emissions tended to be stable. (2) The cumulative emissions of N2O could reach 27.4%~32.6% of the total emissions after one month of basic fertilization. The relationship of the emissions flux and the N2O emission factors among treatments was inorganic>organic + inorganic (1:1)>Organic + Inorganic (3:1). The organic fertilizer reduced the loss of nitrogen in the fertilizer in the form of N2O. Compared with the inorganic fertilizers, the yield of T1 and T2 increased by 9.44% and 6.37% respectively; and the N2O emission intensity of each treatment were reduced. (3) Principal component analysis results showed that soil temperature and moisture content of 0~5 cm were the dominant factors of N2O flux in non-fertilized tobacco fields. Analyzing correlation, temperature and moisture in this treatment were significantly positively and extremely significantly positively correlated with N2O flux, respectively. After fertilization, soil NH4+and soil moisture content were the dominant factors of N2O flux from, and the correlation showed a significant positive correlation (P<0.01). In summary, the N2O flux of tobacco soil was extremely affected by the type of nitrogen fertilizer. After fertilizing, the responses of tobacco field N2O fluxes to soil temperature declined, and the main influencing factors were NH4+ and soil moisture. Under the same nitrogen content, the combined fertilizer of organic and inorganic rate of 1:1 reduced the N2O cumulative emissions significantly, and enhanced the tobacco yield. The cake fertilizer and sheep manure with this organic and inorganic rate reduced the emission intensity by 20.4% and 23.7%, respectively.