不同育秧方式对水稻苗床N2O排放的影响

Effects of different seedling raising methods on N_2O emissions from rice nurseries

基于不同水分管理方式下的水稻育秧方式(分为持续淹水方式下的水育苗床和湿润灌溉水分管理方式下的旱育苗床),研究了不同水稻育秧方式对水稻苗床期N2O排放的影响。研究结果表明:综合不同氮肥施用类型,常规水育苗床系统生育期的N2O平均排放通量介于28.64-34.35μg/(m2.h)。与常规水育方式相比,旱育苗床不同施肥处理的生育期N2O排放总量增加了72%-186%。基于本研究中苗床系统的N2O排放强度,估算出20世纪90年代我国苗床系统的N2O排放总量介于1.46-1.96 Gg/a,占稻田本田N2O排放总量的3%-6%。相对于现在所广泛采用的旱育秧方式,常规采用持续淹水管理方式的水育苗床并增加有机氮肥的投入可以有效地减少水稻苗床期的N2O排放。

Many methods have been employed sofar for forfield measurement of N2O emissions after dee seedlings are transplanted from nursery patches into paddy fields, while N2O fluxes from the seedling nurseries are not well documented in China. We measured N2O fluxes in flee seedling nurseries under the watering regimes of continuous flooding and moist irrigation without waterlogging in southeastern China in 2010. Fluxes of N2O from continuously flooded nurseries averaged 28.64-34.35 μg/（m^2.h） for the different fertilizer applied plots. Compared with the continuous flooding regime, moist irrigation increased the total N2O by 72% - 186% for the different fertilizer applied plots. The N2O emissions from rice seedling nurseries amounted to 1.46-1.96 Gg/a in the 1990s, accounting for 3%-6% of the total amount in dee paddies in China. Applying continuous waterlogging, instead of moist irrigation that has been largely adopted, together with increasing organic N fertilizer inputs would benefit for mitigating N2O emissions in rice seedling nurseries in China.