控释肥料对覆膜栽培稻田N_2O排放的影响

Effect of controlled release fertilizer on nitrous oxide emission from paddy field under plastic film mulching cultivation

采用静态箱-气相色谱法,研究了控释肥料对四川丘陵地区覆膜节水高产栽培稻田N2O排放的影响.结果表明:稻田施用尿素及控释肥料后水稻生长期N2O排放总量分别为(38.2±4.4)和(21.5±5.2)mg N·m-2;施用尿素处理N2O排放系数为0.25%,施用控释肥料处理N2O排放系数为0.14%,减少了43.6%(P<0.05),其中烤田前减少了49.6%(P<0.05);控释肥料可抑制施肥引起的N2O排放峰值,降幅达52.6%;控释肥料对水稻不同生长季节土壤微生物生物量氮、NH4+-N含量和水稻产量均无显著影响;N2O排放与5 cm土壤温度、土壤Eh值无显著相关性.

A field experiment was conducted to assess the effect of controlled release fertilizer on N2O emission in paddy field under plastic film mulching cultivation （PM） with water-saving irriga- tion. Results showed that in the rice growing season, cumulative N2O emissions from the plots applied with urea （PM＋U） and with controlled release fertilizer （PM＋CRF） were （38.2±4.4） and （21.5±5.2） mg N . m^-2, respectively. The N2O emission factors were 0.25% and 0.14% in the treatments PM＋U and PM＋CRF, respectively. The controlled release fertilizer decreased the total N2O emission by 43.6% compared with urea, of which 49.6% was reduced before the drying period. It also reduced the peak of N2O emission by 52.6%. However, it did not affect soil microbial biomass N and soil NH4 ^＋-N content at any rice growing stage, and grain yield either. No significant correlation was observed between N2O flux and soil Eh or soil temperature at the depth of 5 era.