施肥模式对菠萝产量及农田氧化亚氮排放的影响

为探究不同施肥模式下菠萝（Ananas comosus）种植地土壤氧化亚氮（N₂O）的排放特征，筛选出既高产又减少N₂O排放的施肥方法。本试验以热带地区菠萝农田为研究对象，设置不施肥（CK）、常规施肥（NPK）、减量单施化肥（INF）、无机肥+有机肥配施（INF+M）、无机肥+有机肥+缓控肥配施（INF+M+S）等5个处理，利用静态暗箱?气相色谱法对菠萝整个生育期土壤的N₂O排放特征进行监测，并分析不同施肥模式下土壤温度、土壤含水量、硝态氮和铵态氮对N₂O排放的影响及菠萝产量间的差异。结果表明:INF+M+S，INF+M和INF处理下的菠萝产量比NPK处理的分别增加16.77%、6.66%和6.53%，且INF+M+S显著高于NPK。整个菠萝生育期，N₂O累积排放量和平均通量表现为NPK>INF>INF+M>INF+M+S>CK,且处理间差异显著；N₂O排放强度依次为NPK>INF>INF+M>INF+M+S>CK，处理间也表现出显著差异；同时，INF+M+S处理的排放系数也显著低于其他施肥处理；相关性分析发现，土壤硝态氮和铵态氮含量与N₂O排放通量呈极显著正相关。INF+M+S处理能够显著提高菠萝产量，降低菠萝整个生育期农田N₂O的排放量与排放强度，可作为菠萝较优的施肥模式。

Effects of Fertilizer Application on Pineapple Yield and Nitrous Oxide Emission from the Pineapple Field

An attempt was made to explore the N₂O emission characteristics of pineapple (Ananas comosus) soil under different fertilizer treatments to screen out an optimum fertilizer application approach which reduces N₂O emissions and gives high pineapple yield. A fertilizer application trial was arranged in a pineapple field in the tropical region, and five treatments were arranged in the trial: no fertilizer (CK), conventional fertilizer (NPK), single application of fertilizer at a reduced rate (INF), combined application of inorganic fertilizer + organic fertilizer (INF+M), combined application of inorganic fertilizer + organic fertilizer + slow-control fertilizer (INF+M+S). The soil N₂O emissions were monitored by using static black box-gas chromatography, and the relationship of soil temperature, soil moisture, nitrate nitrogen and ammonium nitrogen with N₂O emissions and pineapple yield was analyzed under different treatments. The results showed that the INF+M+S, INF+M and INF treatments increased pineapple yield by 16.77%, 6.66% and 6.53%, respectively, when compared with the NPK treatment. During the whole pineapple growth stage, the N₂O cumulative emission and average flux detected in the treatments were increased in the order of NPK> INF> INF+M> INF+M+S> CK and were significantly different between the treatments. The emission intensity was increased in the order of NPK>INF>INF+M>INF+M+S>CK and was significantly different between the treatments. The INF+M+S treatment had a significantly lower emission coefficient than all the other treatments. The soil N₂O emission flux was significantly positively correlated with soil ammonium nitrogen content and soil nitrate nitrogen content. The INF+M+S treatment increased pineapple yield significantly and reduced the N₂O emission in the pineapple field at the whole growth stage, and it can hence be used as an optimum approach for fertilizer application to pineapple.