氮肥和磷肥对稻田N2O排放的影响

通过模拟南方稻田施用不同量的氮肥和磷肥的实验来探讨N和P对稻田释放N2O的影响.结果表明,水稻田N2O排放通量的较大值主要出现在3次烤田期;氮肥和磷肥对土壤中产生N2O的贡献主要在水稻生长中后期,从第1次烤田起(移栽后34d),氮肥和磷肥都表现为对N2O排放有促进作用;而低氮对N2O排放的刺激作用没有高氮的作用明显,且N2处理(180kg/hm2)、N1处理(90kg/hm2)和N0处理(没有施肥)之间的平均N2O排放差异不显著.在水稻生长中后期(第1次烤田后),N3处理(270kg/hm2)和N4处理(360kg/hm2)的较高水平的氮肥加入能强烈刺激N2O排放.

Influence of nitrogen and phosphorus fertilizers on N2O emissions in rice fields

Through the experiment simulating the application of different amount of nitrogen to explored the influence of N and P and N2O emissions in nice field. The higher N2O emissions flux appeared mainly in the period of three times soil drying in the fields; the contribution of nitrogen and phosphorus fertilizers to the N2O produce in soil occurred mainly in the medium and latter stages of rice growth. Nitrogen and phosphorus fertilizers promoted N2O emissions from the first soil drying in field (after the 34d transplant); but the stimulation of low nitrogen on N2O emission was not obvious as the high emission; and there are no remarked differences in N2O of average emissions among N2 (180kg/hm2), N1(90kg/hm2) and N0(0kg/hm2). In the medium and latter stages (after the first soil drying in field) addition of higher level N fertilizer N3(270kg/hm2) and N4(360kg/hm2) could stimulate strongly N2O emissions.