[Estimation of N2O Emission from Anhui Croplands by Using a Regional Nitrogen Cycling Model IAP-N]

N2O emissions from seven categories of Anhui croplands in 2011 were estimated by using a regional nitrogen cycling model IAP-N. The required statistical data were from each city's statistical yearbook in Anhui Province. The emission factors were from the published field data. The results showed that total N2O emissions from Anhui croplands in 2011 were 35. 1 thousand ton, in which direct and indirect N2O emissions were, respectively, 27. 6 thousand ton and 6. 6 thousand ton, and N2O emission from residues/straws burning in the field was 800 ton. Huaibei Plain (Region I) and Jianghuai Hilly (Region II) were the main contribution regions in Anhui, accounting for 41% and 35% of its regional total N2O emissions, respectively. The most important source for direct N2O emission is the year round upland fields with 74% contribution of the province total direct N2O emission. The second important source in Region II and Region III is upland cropping season of the rotation fields with rice and upland-crops, accounting for 19% and 14% , respectively. While in Region IV, the second direct N2O emission sources are tea gardens and orchards, accounting for 22%. About two-thirds of the indirect N2O were from atmospheric nitrogen deposition. The results can provide a scientific basis for policy makers to make agricultural soils GHG mitigation measures in Anhui Province, such as reasonable use of fertilizers.