包膜/抑制剂联合调控对农田土壤N2O排放和氨挥发的影响

Combined effects of coating/inhibitors on N_2O emission and ammonia volatilization in farmland soil

采用密闭式静态箱-气相色谱法和通气法研究了盆栽试验条件下包膜/抑制剂结合型肥料对土壤N_2O排放和氨挥发的影响。结果表明:与普通尿素(U)相比,包膜/抑制剂结合型尿素(T2~T4)延迟了土壤N_2O排放和氨挥发出现峰值的时间。包膜尿素(T1)、含有抑制剂的包膜尿素(T2)、抑制剂涂层尿素后包膜(T3)、包膜尿素与抑制剂混合(T4)处理N_2O累积排放量比U处理显著减少了27%、39%、49%、39%(P<0.05),T3处理N_2O累积排放量最小,为0.87 kg N·hm-2,显著低于其他处理(P<0.05),T2和T4处理之间差异不显著(P>0.05);包膜/抑制剂型肥料能够减少土壤氨挥发,T3处理氨挥发量最小,为13.68 kg N·hm-2,与U处理相比,T2、T3和T4处理氨挥发量分别显著减少了34%、45%和31%(P<0.05);T2和T3处理玉米产量分别比U处理显著提高13.03%和17.98%(P<0.05);T3处理氮素利用率最高,为58.22%;成本效益分析结果表明,T3与其他处理相比经济净效益最大,为3 061.6元·hm-2。综上,包膜/抑制剂结合型尿素可以减少土壤N_2O排放和氨挥发的气态损失,提高产量和氮素利用率,其中抑制剂涂层尿素后包膜(T3)处理效果最佳。

We examined the effects of coated fertilizer plus inhibitors on N2O emission and ammonia volatilization from soil using both closed static chamber-gas chromatography and aeration methods in pot experiments. Our results showed that the application of encapsulated urea in combination with inhibitors could delay the peak occurrence of N2O emission and ammonia volatilization compared with urea treatment（U）alone. Cumulative N2O emissions from the treatments using film-coated urea（T1）, film plus inhibitor-coated urea（T2）, inhibitor-coated urea encapsulated by film（T3）, and film-coated urea blended with inhibitors（T4）were significantly lower than that of U by 27%, 39%, 49%,and 39%, respectively. The N2O emission from T3 was the lowest（0.87 kg N·hm^-2）. There was no significant difference in N2O emission between T2 and T4 treatments. Similarly, coated fertilizer plus inhibitors reduced soil ammonia volatilization. Ammonia volatilization under the T3 treatment was the lowest, at 13.68 kg N·hm^-2. The amount of ammonia volatilization under treatments T2, T3, and T4 were significantly lower than that under U by 34%, 45%, and 31%, respectively. Maize yields under treatments T2 and T3 were 13.03% and 17.98% higher than that under U treatment, respectively. Nitrogen utilization efficiency under treatment T3 was up to 58.22%. Ultimately, the cost and benefit analysis results showed that, compared with that of the other treatments, the net benefit of T3 was the largest（3 061.6 yuan·hm^-2）. Thus,coated urea plus inhibitors could reduce ammonia volatilization and N2O emission, and subsequently increase nitrogen utilization efficiency and maize yield. Moreover, T3 was more effective than other fertilizers.