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本试验利用渗滤池设施，采用化学分析和同位素技术相结合的方法研究了北京地区潮土表层中施用氮肥后ＮＯ－Ｎ的转化积累及其１３０ｃｍ土体的淋洗状况。常规分析结果表明，在春小麦和夏玉米的生育前期可以观察到氮素明显地向ＮＯ－Ｎ的转化积累，其强度随尿素施用量的增加而明显增加，而尿素、硝铵、硫铵等不同氮肥品种处理之间有差异但大多不显著。同时夏玉米期间转化积累作用比春小麦期间强烈。￣（１５）Ｎ标记试验结果表明，在春小麦生育前期氮素向ＮＯ－Ｎ转化积累的过程中，同时发生了肥料氮的固持和损失，并且土壤本身氮素在这种转化过程的初期占有优势。ＮＯ－Ｎ淋洗出１３０ｃｍ土体主要发生在降雨集中季节，淋失量与同期降雨量线性相关显著；淋失水中ＮＯ－Ｎ含量在施氮肥的处理区大多超过饮用水卫生标准即１０ｍｇＮＯ－Ｎ／Ｌ的限额，平均含量最高可达３３ｍｇＮＯ－Ｎ／Ｌ，这对本地的地下水会造成短期的硝酸盐污染。但是淋洗损失的总量不高。
In this experiment, we use the method of chemical analysis and isotope techniques to study the conversion and accumulation of NO-N and the rinsing of 130cm soil in the surface layer of alluvial soil in Beijing area. Routine analysis showed that the accumulation of NO-N significantly increased in the early growth stages of spring wheat and summer maize, and its intensity increased significantly with the increase of urea application. However, urea, ammonium nitrate and ammonium sulfate were different There are differences between the treatment of nitrogen fertilizer varieties but mostly not significant. At the same time, the effect of transformation and accumulation during summer maize was stronger than that of spring wheat. (15) N-labeled test results showed that during the early stage of spring wheat nitrogen accumulation and conversion to nitrogen and nitrogen, fertilizer nitrogen fixation and loss occurred at the same time, and the soil nitrogen itself in the early stage of this transformation dominated . NO-N leaching out of 130cm soil mainly occurs in the rainfall season, the leaching loss is linearly correlated with the rainfall in the same period; the content of NO-N in the leaching water mostly exceeds the sanitary standard of drinking water, namely 10mgNO- N / L limits, the average content of up to 33mgNO-N / L, which will cause short-term nitrate pollution of local groundwater. However, the total amount of leaching loss is not high.