氮素在盐碱稻田内的动态变化及潜在环境影响分析（摘要）

目的]分析氮素在盐碱稻田内的动态变化及潜在环境影响。方法]以松嫩平原典型苏打盐碱地水稻田为研究对象,采用田间试验方法研究了该区水稻田中的氮素动态变化及其对环境的潜在影响。结果]试验区土壤属强碱土,CEC、C/N比值都较高,保肥能力差;2年试验期内,田表水中的盐碱化指标含量波动较大;试验初期总氮和氨氮浓度达到最高值,之后随时间的推移而下降,强降雨对其影响较大;硝态氮浓度出现峰值晚于总氮和氨态氮,之后随时间的推移而下降;试验期间,氨挥发损失占总氮损失的18.9%～28.8%;田面水中总氮浓度均高于国家地表水环境质量III类标准;农田退水中的非离子氨浓度较高,对下游查干湖鱼类养殖存在危害。结论]为盐碱地治理和水体和渔业资源保护提供了理论依据。

Dynamic Changes of Nitrogen in Saline-alkaline Paddy Field and Its Potential Environmental Impacts

Objective] The paper was to study the dynamic changes of nitrogen in saline-alkaline paddy field and its potential environment impacts. Method] With typical sodic saline-alkaline paddy fields of Songnen Plain as study object,field test method was used to explore the dynamic changes was strong alkof nitrogen in paddy field of the region and its potential impact on environment. Result] The soil in test regionaline with high CEC and C/N ratios,as well as poor preserving capacity of fertilizer. During the two-year field experiment,the indicators of salinization fluctuated. Initially,the concentrations of total nitrogen and ammonia nitrogen reached their maximum values,then decreased over time as a result of heavy rain. The maximum of nitrate concentration appeared later than those of total nitrogen and ammonia nitrogen. Ammonia volatilization accounted for 18.9%-28.8% of the nitrogen loss. The total nitrogen concentration in surface water was higher than the national Class Ⅲ surface water environmental quality standard. The concentration of ammonia from the recession flow of agricultural field was considerably high,which would potentially threaten the fishery in the downstream of Chagan Lake. Conclusion] The study provided theoretical basis for saline-alkaline soil management and conservation of water and fishery resources.