Abstract: Different methods were used to estimate N₂O emissions from croplands in China, characteristics of the emissions analyzed and potential mitigation options discussed in this study. Direct N₂O emissions from croplands estimated on the basis of field measurements and with the IPCC Phase Ⅱ methodology were 398 and 336 Gg, respectively for the year of 1995. By using the methodology, the input of N of four different sources Chinas croplands received in 1949,1955,1960,1965,1970,1975,1980,1985,1990 and 1995 was calculated with results showing that the skyrocketing of the consumption of synthetic N fertilizers was the main reason for the increase in N₂O emissions from croplands in China. Nitrous oxide emissions from paddy fields and uplands were identified. About 22% of the direct N₂O emissions from croplands in China were from paddy fields. Nitrous oxide emissions from paddy field during the rice growing season accounted for 9% of the total emissions from croplands. Therefore, paddy field is a non negligible source of N 2O. According to agricultural characteristics such as cropping system, fertilization and water management, options like modifying N∶P∶K ratios, narrowing the interregional differences in fertilizer N application rate, applying nitrification inhibitors and controlled release fertilizers may help reduce N₂O emissions from the croplands of China.

Key words: croplands, analysis, estimation, mitigation, N₂O emissions, China