不同施肥措施对河套灌区盐化潮土氨挥发及氧化亚氮排放的影响

本研究以河套灌区农田盐化潮土为研究对象,通过静态暗箱-气相色谱法和田间土壤氨挥发原位测定法(通气法),研究了4种不同施肥措施(农民习惯施肥、膨润土+农民习惯施肥、生物炭+农民习惯施肥、腐殖酸+农民习惯施肥,分别标记为CK、B、C、HA)对土壤氨(NH_3)挥发及氧化亚氮(N_2O)排放的影响。结果表明:B处理可以显著降低土壤N_2O的排放,其N_2O累计排放量较CK降低30.9%,氮肥损失率较CK降低31.5%;其他处理N_2O累计排放量与CK无显著差异。各处理NH_3挥发速率于施肥灌水后3~5 d达到峰值,之后逐渐降低趋于平稳。B、C、HA处理可以显著降低土壤NH_3挥发,NH_3累计挥发量较CK降低56.0%、41.2%、49.0%,氮肥损失率较CK降低56.0%、41.2%、52.1%。相关性分析表明,土壤温度和空气温度与土壤N_2O的排放呈显著正相关;生育期土壤含水量处于151.2~203.3 g/kg,在这一范围内,土壤含水量与土壤N_2O的排放呈正相关关系。B处理可显著降低土壤NH3挥发及N_2O排放,且比CK增产11.1%,是较为合理的施肥措施。

Influence of Different Fertilization Measures on NH3 Volatilization and N2O Emission in Salined Flavo-aquic Soil of Hetao Irrigation Area

NH3 volatilization and N2O emission under different fertilization of a salined flavo-aquic soil in Hetao Irrigation Area studied through the static chamber gas chromatography and in situ field determination, the different fertilization included 1) CK, farmer conventional fertilization, 2) B, bentonite + CK, 3) C, biochar + CK, and 4) HA, humic acid + CK. The results showed that: compared with CK, B fertilization significantly reduced the cumulative emission of soil N2O by 30.9% and decreased nitrogen loss by 31.5%, but there were no significant difference between the other fertilization and CK in N2O cumulative emission. The NH3 volatilization rate of each treatment reached the peak value in 3–5 days after fertilization, and then gradually tended to be stable. Compared with CK, B, C, and HA treatments significantly reduced total amount of soil NH3 volatilization by 56.0%, 41.2% and 49.0%, and decreased nitrogen loss rate by 56.0%, 41.2% and 52.1%, respectively. Soil temperature and air temperature were significantly positively correlated with soil N2O emission; Soil water content ranged from 151.2 g/kg to 203.3 g/kg in maize growth period in which soil moisture content and soil N2O emission were positively correlated. B fertilization significantly reduced soil NH3 volatilization and N2O emission, and increased crop yield by 11.1% compared to CK, which indicate it is the more reasonable fertilization.