Zhang Jia-En, Ouyang Ying, Huang Zhao-Xiang
Department of Ecology, College of Agriculture, South China Agricultural University, Guangzhou, China.
Arch Environ Contam Toxicol. 2008 Feb;54(2):167-72. doi: 10.1007/s00244-007-9014-4. Epub 2007 Aug 25.
Agricultural activities are important contributors to the emissions of greenhouse gases. This study ascertained the dynamic emission of nitrous oxide (N(2)O) from a paddy field under a rice-duck farming system in South China. Two different cultivation and fertilizer treatments, namely, organic fertilizer + ducks (OF+D) and chemical fertilizer + ducks (CF+D) treatments, were employed in this study. Experimental data showed that diurnal variations of N(2)O emission were highly correlated with the activities of ducklings. The rates of N(2)O emission were normally increased in the early morning and late afternoon due to the frequent movement of ducklings at these time periods. Our study further revealed that the rates of N(2)O emission from the paddy field varied with the types of fertilizers used as well as with the stages of the rice growth. In general, the rates of N(2)O emission were higher for the CF+D treatment than for the OF+D treatment, whereas more N(2)O was emitted from the paddy field at the tillering stage than at the heading stage. The global warming potential with the use of the organic fertilizer was about 22% lower than with the use of the chemical fertilizer.
农业活动是温室气体排放的重要来源。本研究测定了中国南方稻鸭共作系统下稻田一氧化二氮（N₂O）的动态排放情况。本研究采用了两种不同的种植和施肥处理方式，即有机肥+鸭（OF+D）处理和化肥+鸭（CF+D）处理。实验数据表明，N₂O排放的日变化与小鸭的活动高度相关。由于小鸭在清晨和傍晚时段频繁活动，这两个时段的N₂O排放速率通常会增加。我们的研究进一步表明，稻田N₂O的排放速率会因所用肥料类型以及水稻生长阶段的不同而有所变化。总体而言，CF+D处理的N₂O排放速率高于OF+D处理，而稻田在分蘖期的N₂O排放量高于抽穗期。使用有机肥时的全球变暖潜势比使用化肥时低约22%。
