肥水管理方式对蔬菜田N2O释放影响的模拟研究

通过田间静态箱监测和DNDC模型模拟的方法，对比研究了崇明岛东滩蔬菜田在常规肥水管理和精确滴灌施肥方式下N2O的排放情况，从排放特征、全年通量、单位氮肥N2O损失率以及单位作物产量排放量等方面分析了不同肥水管理方式对旱田土壤N2O排放的影响。 结果表明，基于土壤和作物养分平衡管理的精确滴灌施肥技术，由于减少了氮肥施用量并改进了肥水分配方式，提高了肥料的利用效率，在保持农作物产量的基础上减少了N2O的排放。与常规肥水管理方式相比，滴灌施肥区2006年和2007年的N2O排放通量分别减少6.2和6.8 kg N·hm^-2·a^-1，单位氮肥N2O损失率明显降低，2006年和2007年单位产量排放量分别削减53.2％和58.9％。

Simulation of Some Impacts of Fertilization and Water Management on Nitrous Oxide Emissions from Vegetable Field

The emissions of nitrous oxide from vegetable fields were studied through the field monitoring with the static chamber method and the simulation with DNDC model. The impacts of drip fertigation on nitrous oxide emission were compared to the conventional irrigation and fertilization strategy in terms of emission characteristics, annual fluxes, losses rates of nitrogen fertilizers, and emission flux per crop yields. It was showed that with the drip fertilizer irrigation, due to the saving of the nitrogen fertilizers and the increase of fertilizer utilization efficiency, the N2O emission flux was reduced significantly without compromising crop yields. Compared with the conventional fertilization and irrigation strategy, the N2O flux was reduced by 6.2 kg ·hm^-2·a^-1 and 6.8 kg ·hm^-2·a^-1 in 2006 and 2007, respectively, and the loss rate of nitrogen fertilizer was lowered as well. Meanwhile, the N2O flux per unit crop yield was decreased by 53.2% and 58.9% in 2006 and 2007, respectively.