控释肥料对稻田氧化亚氮排放的影响

采用静态箱法研究了控释肥料和常规肥料处理对华南赤红壤发育的稻田N₂O排放的影响. 结果表明,施用控释肥处理与非包膜复合肥处理,在水稻移栽后10 d内水层中NH₄+-N和NH₃--N浓度间差异达极显著水平,各处理水层中NH₃--N浓度与2 d后或当天N₂O排放量间的偏相关系数达极显著水平.包膜型控释肥比未包膜复合肥能极显著地降低稻田N₂O的排放量.在施肥后100 d内,控释肥的N₂O累积排放量仅为未包膜型复合肥料的13.45%～21.26%,是尿素处理的71.17%～112.47%.复合肥处理的N₂O排放主要集中在施肥后1～25d和水稻晒田期间,控释肥在此时期的排放量显著降低,尿素处理则延缓并减小了N₂O排放峰.控释肥一次施用和尿素分次施用都能减少N₂O排放.

Effects of controlled release fertilizers on N2O emission from paddy field

With close chamber method,this paper studied the effects of controlled release fertilizer (CRF),non-coated compound fertilizer (Com) and conventional urea (CK) on N₂O emission from paddy field. The results showed that within 10 days after transplanting,the ammonium and nitrate concentrations in the surface water of the plot treated with CRF were significantly different from those treated with Com. The partial coefficient between N₂O emission rates and corresponding nitrate concentrations in the water was significantly high (r=0.6834). Compared with Com,CRF was able to reduce N₂O emission from the paddy field. Within 100 days after basal application,the N₂O emission rate of treatment CRF was only 13.45%～21.26% of Com and 71.17%～112.47% of CK. The N₂O emission of Com was mainly concentrated in 1～25 d after basal fertilization and mid-aeration period,but that of CRF was remarkably lower during same period,while the peak of N₂O emission of CK was postponed and reduced. It was concluded that both one-time fertilization of CRF and several-time fertilizations of conventional urea were able to reduce N₂O emission from the paddy field.