三种控释肥在赤红壤中的氧化亚氮排放

Effects of applying controlled release fertilizers on N_2O emission from a lateritic red soil

采用静态箱收集和对比法,研究了无作物种植条件下包膜与否对高氮、均衡及高钾3种氮磷钾配比复合肥在华南赤红壤发育的菜园土中氧化亚氮(N2O)排放情况.结果表明:肥料氮磷钾配比不同,N2O排放量差异显著,3种类型复合肥N2O累积排放量表现为均衡型≥高氮型>高钾型;同一类型复合肥,包膜控释能显著降低N2O排放量,包膜控释高氮、均衡及高钾型复合肥N2O排放总量分别为不包膜复合肥N2O排放量的34.4%、30.5%和89.3%;与不包膜相比,复合肥包膜能降低肥料在土壤中的N2O日排放通量,滞后和削减N2O排放高峰,减少土壤氮素损失以及由N2O排放造成的全球增温潜势.

Static closed chamber technique and contrast method were adopted to study the effects of three coated compound fertilizers （N：P2O5：K2O=19：8.6：10.5, high N; 14.4：14.4：14.4, balanced NPK; and 12.5：9.6：20.2, high K） on the N2O emission from a lateritic red soil under the condition of no crop planting, taking uncoated compound fertilizers （N：P2O5：K2O=20：9：11, high N; 15：15：15, balanced NPK; and 13：10：21, high K） as the contrasts. Different formula of fertilizer NPK induced significant difference in the N2O emission. Under the application of uncoated compound fertilizers, the cumulative N2O emission was in the order of balanced NPK ≥ high N high K. Applying coated compound fertilizers decreased the N2O emission significantly, and the emission amount under the application of high N, balanced NPK, and high K was 34.4%, 30.5%, and 89.3% of the corresponding uncoated compound fertilizers, respectively. Comparing with the application of uncoated compound fertilizers, applying coated compound fertilizers also decreased the daily N2O flux significantly, and delayed and shortened the N2O peak, suggesting that coated fertilizers could reduce soil nitrogen loss and the global warming potential induced by N2O emission.