~(15)N制剂价格昂贵,特别是随丰度提高,其价格按几何级数增加,是在田间进行氮肥示踪试验的限制因子.目前国内在这类实验中,多采用10%左右的丰度水平.一项田间微区试验,加上样品质谱分析费用,往往需要数千元的经费,大大限制了试验工作的开展.如果采用较低的丰度水平,也能达到示踪实验的目的,则试验经费可大量节约,试验规模可能扩大,应用范围可更加普及.过去的~(15)N示踪实验中,曾有过不少应用较低丰 ~ (15) N preparation is expensive, especially with the increase in abundance, the price increases by geometric series, is the limiting factor in the field of nitrogen fertilizer tracer test currently used in such experiments, the use of about 10% Abundance level.A field micro-area test, coupled with the cost of sample mass spectrometry analysis, often requires several thousand yuan of funding, greatly limiting the test work carried out.If the lower abundance level, but also to achieve the tracer experiment Purpose, the trial funding can be a lot of savings, the pilot scale may be expanded, the scope of application can be more universal. In the past ~ (15) N tracer experiments, there have been many applications less abundant