降雨对岩溶区水田旱地土壤溶液氮素运移的影响OA
Impact of Rainfall on Nitrogen Transport in Soil Solution of Paddy Fields and Drylands in Karst Regions
理解降雨事件中不同水分管理模式农田氮素的垂向迁移规律,对于脆弱岩溶农业生态系统的水污染防治至关重要.以桂林市会仙湿地岩溶农业区为研究对象,开展原位监测与相关性分析,对比研究了旱作与稻田降雨事件中土壤溶液氮素(氨氮NH4+-N、硝酸盐氮NO3--N、总氮TN)的时空动态,采用皮尔逊相关性分析了土壤溶液氮素与降雨特征、地下水位的关系.结果表明,氮素迁移转化在两种耕作模式中存在显著差异:旱作条件下,降雨淋溶导致NO3--N在60 cm土层显著累积(峰值:41.138 mg/L)并快速淋溶至地下水,驱动氮素向深层土壤中迁移;淹水系统中,受地下水位波动引发的氧化还原界面位移影响,雨后NO3--N在深层土壤富集(NO3--N占TN比例高达80.78％),易引发地下水突发性污染.结论表明,岩溶区农业区域60～100 cm土层可作为氮素转化迁移的关键缓冲带,应优化灌溉施肥时序,尽量避开降雨高峰从而减少土壤养分流失.
This study investigates the vertical migration and transformation of nitrogen in response to rainfall events under dryland and paddy farming systems in a vulnerable karst agricultural area in the Huixian Wetland,Guilin.Through in-situ monitoring and Pearson correlation analysis,distinct patterns were identified between the two systems.In dryland conditions,rainfall leaching led to significant nitrate-nitrogen(NO3--N)accumulation in the 60 cm soil layer(peak:41.138 mg/L),with rapid leaching into groundwater.In contrast,paddy systems exhibited a marked decrease in the NO3--N/TN ratio and an increase in the NH4+-N/TN ratio in the top 30 cm soil.However,NO3--N dominated(up to 80.78％of TN)in deeper soil layers(>60 cm)and groundwater,driven by redox interface shifts associated with water table dynamics.The 60～100 cm soil horizon was identified as a critical buffer zone for nitrogen migration.Optimizing irrigation and fertilization timing to avoid rainfall peaks is recommended to mitigate groundwater contamination.
谭映晴;代俊峰;龚春瑾;万祖鹏;黄凯
桂林理工大学环境科学与工程学院,广西 桂林 541006流域保护与绿色发展广西高校工程研究中心,广西 桂林 541006||广西环境污染控制理论与技术重点实验室,广西 桂林 541006桂林理工大学环境科学与工程学院,广西 桂林 541006流域保护与绿色发展广西高校工程研究中心,广西 桂林 541006||广西环境污染控制理论与技术重点实验室,广西 桂林 541006广西水利科学研究院,广西 南宁 530023
农业科技
土壤溶液降雨氮素迁移岩溶区旱地水田
soil solutionrainfallnitrogen transportkarst areadrylandpaddy field
《节水灌溉》 2026 (4)
79-85,7
国家自然科学基金项目(52269010)广西重点研发计划(桂科AB25069160).
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